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Emergency Radiology ER001-EB-X Ultrasound Evaluation of the Symptomatic Popliteal Fossa: It's Not All Baker's Cysts All Day Room: ER Community, Learning Center Participants Peter M. Ghobrial, MD, Chardon, OH (Presenter) Nothing to Disclose Richard L. Barger JR, MD, Painesville, OH (Abstract Co-Author) Nothing to Disclose Ravi Guttikonda, MD, Cleveland, OH (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The popliteal fossa is a common site of pain and other symptoms for patients prompting evaluation. Ultrasound (US) is very often used to begin, and frequently complete imaging evaluation of symptomatology at this location. After viewing this presentation the learner will accomplish the following:1. Review constituent anatomy of the popliteal fossa. 2. Discuss a concise US scanning protocol for popliteal fossa evaluation, with emphasis on normal sonographic anatomy. 3. Review the differential diagnosis of various causes of popliteal fossa symptoms through an US case based approach, with multimodality correlation in some instances. TABLE OF CONTENTS/OUTLINE Introduction Anatomy of the Popliteal Fossa Ultrasound Protocol for Popliteal Fossa Evaluation The "Normal" Popliteal Fossa at Ultrasound Ultrasound Diagnosis of the "Baker's Cyst" Case Based Review of Causes of Popliteal Fossa "Lump" and "Pain" Conclusion References ER003-EB-X Pitfalls in Pediatric Musculoskeletal Imaging: Normal Variants Causing Problems for the Radiologist in the Pediatric Emergency Department All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Matthew Hermann, MD, Ann Arbor, MI (Presenter) Nothing to Disclose Jessica R. Leschied, MD, Ann Arbor, MI (Abstract Co-Author) Nothing to Disclose Suzanne T. Chong, MD, Ann Arbor, MI (Abstract Co-Author) Nothing to Disclose Peter J. Strouse, MD, Ann Arbor, MI (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Following review of this educational exhibit, the learner will:1. Recognize the more common osseous variants in the pediatric cervical spine and extremities that can cause difficulty in radiographic interpretation. 2. Identify some of the accessory centers of ossification in the foot and ankle that should not be confused for fractures. 3. Understand the variable appearance of centers of ossification in the pediatric extremities. 4. Contrast normal variants with actual pathology using case examples. TABLE OF CONTENTS/OUTLINE A. Background and relevance in the pediatric emergency departmentB. Cases and review of imaging findings (examples of what will be shown):Skull: normal and accessory suturesC-spine: Pseudosubluxation of the cervical spinePelvis: Ischiopubic synchondrosis; os acetabuli; superior pubic ramus developmental variantExtremities:- Physiologic Periosteal reaction of the infant- Irregularity of the distal femoral epiphysis- Bipartite patella/dorsal defect of the patella- Irregularity of the distal femoral metaphysis/cortical desmoid- Accessory ossicles of the foot and ankle- Fifth metatarsal apophysis- Bifid great toe phalangeal epiphysisDifferentiation of normal metaphyseal development from child abuse fracturesC. Normal variants vs. actual pathologyD. Conclusion ER005-EB-X Abdominal Vascular Emergencies (AVE): How to Improve Diagnosis using DECT All Day Room: ER Community, Learning Center Participants Khalid W. Shaqdan, MD, Boston, MA (Presenter) Nothing to Disclose Anushri Parakh, MBBS, MD, Basel, Switzerland (Abstract Co-Author) Consultant, Bayer AG Laura L. Avery, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose George R. Oliveira, MD, East Boston, MA (Abstract Co-Author) Nothing to Disclose Avinash R. Kambadakone, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Dushyant V. Sahani, MD, Boston, MA (Abstract Co-Author) Research support, General Electric Company; Medical Advisory Board, Allena Pharmaceuticals, Inc TEACHING POINTS Abdominal vascular emergencies are challenging clinical pathologies with high mortality. Imaging patients for AVE is continually increasing, with CT as the preferred modality. Dual-energy CT (DECT) offers material-specific reconstructions, monoenergetic imaging, and increasing CNR reducing iodine utilization and radiation exposure while improving lesion detection. TABLE OF CONTENTS/OUTLINE Introduction Clincal aspects of AVE and management CT protocols Aorta CTA CTV Mesenteric bowel ischemia DE data acquisition, image processing, and reconstruction VNC Monoenergetic images Case based review of vascular pathologies Rupture and impending rupture of AAA Celiac artery dissection Acute mesenteric ischemia Rupture of visceral aneurysms Portal vein and IVC thrombosis DECT workflow Limitations Conclusion Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Dushyant V. Sahani, MD - 2012 Honored Educator Dushyant V. Sahani, MD - 2015 Honored Educator Dushyant V. Sahani, MD - 2016 Honored Educator Laura L. Avery, MD - 2016 Honored Educator ER006-EB-X Imaging of Penetrating Trauma to the Brain All Day Room: ER Community, Learning Center Participants Ajay K. Singh, MD, Boston, MA (Presenter) Nothing to Disclose Mona T. Vakil, MD, Los Angeles, CA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. CT is helpful in deciding definitive surgical management in patients who necessitated surgery after CT. 2. CT, MR and CT angiography are key imaging modalities that are frequently used to determine the course of the foreign object and the extent of brain tissue injury as well as to rule out vascular injury. 3. Early surgical exploration by a multidisciplinary team approach is essential to attain good recovery and a favorable outcome. TABLE OF CONTENTS/OUTLINE Self-inflicted trauma is the more common mechanism Types: High velocity & low-velocity trauma Mortality from isolated intracranial injury = approx 41% Imaging: CT with and without CT angiography Imaging provides information on entrance and exit wounds, missile track & secondary changes CT angiography has limited overall sensitivity in detecting arterial injuries but is accurate in identifying traumatic intracranial aneurysm.Pathophysiology: Biometry reveals destruction zone of 3.6 cm around the permanent track (temporary cavity). Axonal injury present at sites remote from the permanent cavity Complications: Local wound infection Meningitis Brain abscess Cerebrospinal fluid leaks Aneurysm and bleeding HydrocephalusTreatment: Removal of a penetrating foreign object with direct visualization and after preparations for vascular control. ER007-EB-X Imaging of Necrotising Fasciitis All Day Room: ER Community, Learning Center Participants Ajay K. Singh, MD, Boston, MA (Presenter) Nothing to Disclose Sergey Kochkine, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Necrotising fasciitis is rapidly progressive, often fatal infection of soft-tissue fascia deep to the skin and superficial to the muscles.2. The diagnostic feature on CT is the presence of soft tissue gas and deep fascial crescenteric fluid collections. TABLE OF CONTENTS/OUTLINE Necrotising fasciitis is rapidly progressive, often fatal infection of soft-tissue fascia deep to the skin and superficial to the muscles.Epidemiology More common in immunocompromised patients (HIV, DM etc.).Pathology Most common type: polymicrobial infection Single organism (most commonly group A streptococci) LocationExtremities, perineum, and truncal areas most commonly involved Radiographic features Soft-tissue thickening from cellulitis Gas in the soft tissues Asymmetrical fascial thickening associated with fat stranding Edema extending into the inter-muscular septa Thickening of superficial and/or deep fascial layers Abscess MRI: Modality of choice for detailed evaluation of soft tissue infectionTreatment and prognosis Fasciotomy with debridement ER100-ED-X Leaking Ureter: Why Do We Struggle to Detect Ureteral Injuries on Multimodality Imaging? All Day Room: ER Community, Learning Center Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Christine O. Menias, MD, Chicago, IL (Abstract Co-Author) Nothing to Disclose David Dreizin, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Sanjeev Bhalla, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Man Hon, MD, Forest Hills, NY (Abstract Co-Author) Nothing to Disclose Andres O'Brien, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To illustrate critical imaging findings in blunt and penetrating traumatic and iatrogenic ureteral injuries. To discuss the advantages and disadvantages of different imaging modalities for the diagnosis of ureteral injuries. To review the clinical and imaging literature on ureteral injuries, with an emphasis on potential pitfalls, and missed injuries. TABLE OF CONTENTS/OUTLINE Traumatic ureteral injuries are rare and can be easily overlooked by the radiologist due to multiple concomitant injuries, the absence of delayed images, and the non-specific clinical presentation. The majority of non-iatrogenic cases are caused by gunshot wounds. Blunt ureteral injuries are very uncommon, but can be encountered in severe multitrauma patients. Iatrogenic injuries can occur during gynecologic, bowel and vascular surgery. The role of MDCT, IVP and retrograde pyelography will be explored and demonstrated. Potential pitfalls in imaging evaluation, including specific features of incomplete ureteral transection, will be highlighted. Differential diagnosis and management options with an emphasis on interventional radiology will be discussed. This exhibit offers an opportunity to review the imaging appearance of traumatic and iatrogenic ureteral injuries and emphasizes the role of radiologist in the detection and management of these life-threatening entities. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Christine O. Menias, MD - 2013 Honored Educator Christine O. Menias, MD - 2014 Honored Educator Christine O. Menias, MD - 2015 Honored Educator Christine O. Menias, MD - 2016 Honored Educator Sanjeev Bhalla, MD - 2014 Honored Educator Sanjeev Bhalla, MD - 2016 Honored Educator Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator ER102-ED-X Gallbladder: What's New in Gallbladder Imaging with Emphasis on Dual Energy CT All Day Room: ER Community, Learning Center Awards Identified for RadioGraphics Participants Jennifer W. Uyeda, MD, Boston, MA (Presenter) Nothing to Disclose Ian Richardson, BS, Boston, MA (Abstract Co-Author) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG TEACHING POINTS Common gallbladder pathologies can be evaluated on varioius imaging modalities including US, CT, MRI, HIDA, and PET.Application of DECT post-processing can aid in diagnosis of various gallbladder pathologies including cholelithiasis, acute cholecystitis, and carcinoma and potentially decrease the need for subsequent imaging. TABLE OF CONTENTS/OUTLINE Review pathophysiology of gallstones and other pathologies Review of imaging findings of gallstones and various pathologies on multiple modalities including US, CT, MR, HIDA, and PET. Illustrate the potential applications of dual energy CT post-processing utilizing creation of iodine maps, virtual noncontrast, and virtual monoenergetic images Ability to make noncalcified gallstones visible with virtual monochromatic images Improve detection of acute cholecystitis on CT with iodine maps Differentiate stones from carcinoma Future directions and summary Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ER103-ED-X Missed Acute Appendicitis on MDCT and MRI: Legal Ramifications, Challenges, and Avoidance Strategies All Day Room: ER Community, Learning Center Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Eitan Sosner, BA, Stony Brook, NY (Abstract Co-Author) Nothing to Disclose Abraham H. Dachman, MD, Chicago, IL (Abstract Co-Author) Nothing to Disclose Victoria Chernyak, MD, Bronx, NY (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To discuss the legal ramifications of the missed or incorrect imaging diagnosis of acute appendicitis (AA) by radiologists, which is highly relevant to the current practice of emergency radiologyTo illustrate common misinterpretations in the diagnosis of AA on MDCT and MRI examinations, based on lessons learned from Morbidity & Mortality Rounds. TABLE OF CONTENTS/OUTLINE The failure to diagnose AA is the third most common incorrect gastrointestinal diagnosis resulting in medical malpractice allegations. The medical-legal aspects of missed and/or delayed diagnosis of AA will be reviewed. The misinterpretation of imaging examinations in patients with suspected appendicitis may be caused by suboptimal technique, failure to review a portion of the examination, satisfaction of search error, and the misinterpretation of imaging findings. This exhibit will review optimised MDCT and MRI protocols for the detection of AA. MDCT and MR imaging findings of the following challenging presentations of AA will be also illustrated: tip appendicitis; stump appendicitis; peri-appendicits; and appendicitis on non-enhanced MDCT. This exhibit offers an opportunity to review common mistakes in diagnosis of the AA on MDCT and MRI, to review the imaging, clinical, and legal literature on this specific topic, and also suggests strategies to avoid potential misinterpretations. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator ER104-ED-X Orbital Hemorrhage: Can You Localize the Blood? All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Jeanne Amuta, MD, Bronx, NY (Abstract Co-Author) Nothing to Disclose Meir H. Scheinfeld, MD, PhD, Bronx, NY (Presenter) Nothing to Disclose TEACHING POINTS To understand the anatomy of the orbit and globe.To correctly localize hemorrhage within the orbit and globe.To appreciate the significance of hemorrhage within different locations of the orbit and globe and what are the typical treatments for these conditions. TABLE OF CONTENTS/OUTLINE Orbital anatomy will be illustrated and reviewedCases of orbital hemorrhage will be presented and discussed, including:Hemorrhage within the globe: Retinal hemorrhage Choroidal hemorrhage Vitreous hemorrhage Anterior chamber hemorrhage (hyphema)Hemorrhage anterior to globe: Preseptal hematoma Subconjunctival hemorrhageHemorrhage posterior to the globe: Retrobulbar hemorrhage Retrobulbar hematoma Hemorrhage into the optic nerve sheath Hemorrhage into an extra-occular muscle ER105-ED-X Pelvic CT Angiography in Trauma: 10 Year's of Experience at a Level I Trauma Center All Day Room: ER Community, Learning Center Participants Shahnaz Rahman, MD, Boston, MA (Presenter) Nothing to Disclose Arthur Baghdanian, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Armonde Baghdanian, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Alessandra J. Sax, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jorge A. Soto, MD, Boston, MA (Abstract Co-Author) Royalties, Reed Elsevier Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Pelvic CT angiography may be employed in the trauma setting to evaluate for vascular injuries.2. Understand the utility of arterial, portal venous, and delayed phase imaging in characterizing traumatic vascular injuries. 3. Discuss protocol considerations for incorporation of arterial phase imaging in patients who sustain pelvic trauma. TABLE OF CONTENTS/OUTLINE 1. Illustrate and discuss various CT findings of traumatic vascular injury using arterial, portal venous phase and delayed phase imaging.2. Understand the utility of arterial, portal venous, and delayed phase imaging in characterizing traumatic vascular injuries. 3. Discuss protocol considerations for incorporation of arterial phase imaging in patients who sustain pelvic trauma.4. Illustrate pelvic anatomy using 3D models. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator ER106-ED-X What an On Call Radiology Resident Needs to Know About MR Imaging in Spinal Trauma All Day Room: ER Community, Learning Center Participants Yogesh Kumar, MD, Bridgeport, CT (Presenter) Nothing to Disclose Gerard J. Muro, MD, Southport, CT (Abstract Co-Author) Nothing to Disclose Joshua M. Sapire, MD, Bridgeport, CT (Abstract Co-Author) Nothing to Disclose Kusum Hooda, MBBS, Stratford, CT (Abstract Co-Author) Nothing to Disclose Francisco J. Lazaga, MD, Bridgeport , CT (Abstract Co-Author) Nothing to Disclose Francisco E. Valles, MD, Bridgeport, CT (Abstract Co-Author) Nothing to Disclose Daichi Hayashi, MBBS, PhD, Bridgeport, CT (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To discuss the indications of magnetic resonance imaging (MRI) in spinal trauma. 2. To review the normal anatomy and various MR sequences for adequate evaluation of spinal trauma. 3. To discuss the MRI findings of ligamentous and spinal cord injuries. 4. To explain the role of MRI in evaluating stable versus unstable spinal injuries and predicting prognosis in spinal cord injury. 5. To discuss vascular injuries and their complications, extra medullary collections such as epidural hematoma, subdural hematoma and CSF leaks.6. To review the role of MRI in differentiating benign versus malignant vertebral fractures, and acute versus chronic compression fractures . 7. To review various pitfalls in MRI in spinal trauma. TABLE OF CONTENTS/OUTLINE Normal MRI appearances of spinal ligamentous structures.Mechanisms of Spinal TraumaWhen to suspect ligamentous and cord injuries based on CT findings?Review of imaging findingsSample cases- Various ligament tears. Spinal cord contusions-hemorrhagic and non hemorrhagic. Traumatic disc herniation, vascular injuries and extradural/subdural hematoma. Benign versus malignant vertebral fractures. Acute versus chronic compression fractures. Various artifacts and pitfalls in spinal MRI in trauma. ER107-ED-X Acute Abdominal Diseases on CT and MRI; The Underlying Etiology of Lumber Pain All Day Room: ER Community, Learning Center Participants SHOTA TAKEHARA, Okinawa, Japan (Presenter) Nothing to Disclose Masahiro Okada, MD, Nishihara-Cho, Japan (Abstract Co-Author) Nothing to Disclose Yuko Iraha, Nishihara-cho, Japan (Abstract Co-Author) Nothing to Disclose Kimei Azama, Nishihara City, Japan (Abstract Co-Author) Nothing to Disclose Yuka Morita, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Sadayuki Murayama, MD, PhD, Nishihara-Cho, Japan (Abstract Co-Author) Research Grant, Toshiba Corporation TEACHING POINTS Gastric ulcer, duodenal ulcer, acute cholecystitis, acute pancreatitis, pancreatic necrosis, pyelonephritis, renal cell carcionoma and pancreas cancer etc, which show lumber pain, are reviewed by typical and/or atypical images on CT and MRI.For these acute abdominal diseases, points to bear in mind are shown in this exhibit. TABLE OF CONTENTS/OUTLINE Contents1. General education of acute abdominal diseases with lumber pain.2. CT and MR applications for these abdominal diseases.3. Technical developments for abdominal CT and MR. 4. Quizzes of CT and MR images for acute abdominal diseases with lumber pain.Gastric ulcerDuodenal ulcerUreteral stoneAcute cholecystitisAcute pancreatitisPancreatic necrosisPyelonephritisRenal cell carcionomaPancreas cancerGallbladder cancerIschemic colitis These general review and quizzes are provided for every radiology resident/ fellow. ER108-ED-X New Trends in the Management of Acute Diverticulitis: Imaging Findings and Implications All Day Room: ER Community, Learning Center Participants Marina C. Bernal Fernandez, MD, Boston, MA (Presenter) Nothing to Disclose David D. Bates, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Cecilia Ponchiardi, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Joshua Teich, Boston, MA (Abstract Co-Author) Nothing to Disclose Michael von Plato, Boston, MA (Abstract Co-Author) Nothing to Disclose Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Chaitan Narsule, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Avneesh Gupta, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Detail the recent changes in the surgical management of patients with acute diverticulitis2. Review CT imaging features of diverticulitis that can help guide management3. Discuss the clinical implications of the Hinchey classification as well as the complications of diverticulitis TABLE OF CONTENTS/OUTLINE Epidemiology of Acute Diverticulitis Pathophysiology of Acute Diverticulitis Current Trends and Recent Literature on the Changing Surgical Management of Acute Diverticulitis Imaging Features of Acute Diverticulitis on CT -- Hinchey Classification -Complications and Fistulas -- Pathologic Correlation Images Summary ER109-ED-X Whole Body CT Protocol for Trauma: Review of Arm Positioning with Emphasis on Image Quality and Radiation Dose All Day Room: ER Community, Learning Center Participants Alessandro A. Lemos, MD, Milan, Italy (Presenter) Nothing to Disclose Roberto Brambilla, PhD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Vincent R. Tatco, MD, Quezon City, Philippines (Abstract Co-Author) Nothing to Disclose Maria C. Firetto, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Lucrezia Marica Gentile, l'Aquila, Italy (Abstract Co-Author) Nothing to Disclose Cristiano Sorge, RT, Milan, Italy (Abstract Co-Author) Nothing to Disclose Pietro R. Biondetti, MD, Milano, Italy (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The purpose of this exhibit is:1. To review arm positioning at whole-body CT protocol for trauma. 2. To review the influence of different arm positioning techniques on image quality and radiation dose.3. To learn optimal strategies to minimize beam-hardening artefacts and to reduce radiation dose in patients unable to abduct both or a single arm over the head. TABLE OF CONTENTS/OUTLINE Arm positioning techniques.-Standard arm positioning with overhead abduction of both arms (modified swimmer's position)-Alongside the abdomen in foam sponge ramps (astronaut's position)-On a pillow ventrally (traveler's position).-Only one arm abducted over the head (swimmer's position).Effect on image quality and radiation dose-Summary -The modified swimmer's position is the standard technique to scan polytrauma patients when both arms can be fully abducted over the head.-The traveler's position is the most appropriate technique to reduce beam hardening artefacts when both arms cannot be moved up. However, the radiation dose is higher than that of standard swimmer's position.-We selectively employed swimmer's position to reduce beam hardening artifacts at the base of neck and thoracic inlet. -The astronaut's position should be employed selectively when standard (arms up) CT cannot be performed (i.e.shoulder fractures). ER110-ED-X Chasing the Dragon: America's Opiate Epidemic and the Emergency Radiologist All Day Room: ER Community, Learning Center Awards Identified for RadioGraphics Participants David D. Bates, MD, Boston, MA (Presenter) Nothing to Disclose Katherine M. Gallagher, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer W. Uyeda, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Akira M. Murakami, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Bindu Setty, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Mariza O. Clement, MD, East Meadow, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To recognize key emergency radiology findings by system in patients with opiate use2. To review the pathophysiology of various opiate related conditions that are seen in emergency radiology3. To familiarize the audience with a multimodality imaging approach to opiate related emergency conditions TABLE OF CONTENTS/OUTLINE Epidemiology of opiate abusePathophysiology of opioid related conditionsReview of imaging findings, Pitfalls and Sample Cases-Neuro (including hypoxic brain death, embolic stroke, mycotic aneurysm, heroin leukoencephalopathy)-- Chest (including cardiac valve vegetations, septic embolic, pulmonary artery pseudoaneurysms)-- Gastrointestinal/Genitourinary (including intra-abdominal abscesses, septic emboli to solid viscera)-- Musculoskeletal (including rhabdomyalysis, septic joint, osteomyelitis, bacterial tenosynovitis of the hands on ultrasound)Summary ER111-ED-X Acute Presentations of Colorectal Carcinomas: What Radiologists Need To Know All Day Room: ER Community, Learning Center Participants Manickam Subramanian, MBBS, FRCR, Singapore, Singapore (Presenter) Nothing to Disclose Kabilan Chokkapan, MBBS, MD, chennai, India (Abstract Co-Author) Nothing to Disclose Ashish Chawla, MD, MBBS, Singapore, Singapore (Abstract Co-Author) Nothing to Disclose Jagadish Narayana Shenoy, Singapore, Singapore (Abstract Co-Author) Nothing to Disclose Dinesh D. Chinchure, FRCR, Singapore, Singapore (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To briefly review various acute presentations of colorectal carcinomas. To briefly describe the vital role of computed tomography in the evaluation of acute presentations of colorectal carcinomas. To present in an interactive manner a series of acute presentations of colorectal carcinomas. To briefly review the diagnostic clues that will help radiologists to make an accurate diagnosis. TABLE OF CONTENTS/OUTLINE The cases will be presented in an interactive manner. Key diagnostic points will be highlighted in the discussion of each case. The list of acute presentations of colorectal carcinoma cases includes:Intestinal obstructionPerforation and peritonitisAcute appendicitis and small bowel obstructionAbscessDiverticulitisColovesical fistulaIntussusceptionBleeding due to vascular invasion/erosion. ER113-ED-X Pediatric Non Accidental Head Trauma: Role of MRI and What a Radiologist Should Know ? All Day Room: ER Community, Learning Center Participants Amin Kathan, MD, Chicago, IL (Presenter) Nothing to Disclose Dheeraj Reddy Gopireddy, MD, Chicago, IL (Abstract Co-Author) Nothing to Disclose Oluwaseun O. Babalola, MD, Chicago, IL (Abstract Co-Author) Nothing to Disclose Osbert O. Egiebor, MD, Chicago, IL (Abstract Co-Author) Nothing to Disclose Alexander Ree, MD, Oak Park, IL (Abstract Co-Author) Nothing to Disclose Corinne E. Atty, DO, Chicago, IL (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Trauma is the most common cause of death in childhood, and non accidental head trauma is the most common cause of traumatic death and morbidity in infants younger than 1 year. In this electronic exhibit we demonstrate key MRI imaging features indicative of brain trauma in this pediatric population.Emphasis is also laid on key imaging sequences, common pitfalls and differential diagnosis as well. TABLE OF CONTENTS/OUTLINE MRI imaging detected nearly four times as many intraparenchymal lesions (43%) as compared with CT imaging (11%). Cases of abusive head trauma in young children five years of age and younger has more than doubled, from 13.7 to 28.9 per 100,000 in last few years.3 times as many intraparencheymal lesions were detected by MRI (44%) compared to CT (15%) Key focus areas include : Skull fracturesSubdural and epidural hematomasHemorrhagic contusionDiffuse axonal injury ER114-ED-X Radiology Reflexes: When Recommending Another Study is Required for a Complete Diagnosis All Day Room: ER Community, Learning Center Awards Cum Laude Participants Meir H. Scheinfeld, MD, PhD, Bronx, NY (Presenter) Nothing to Disclose Robert J. Dym, MD, Bronx, NY (Abstract Co-Author) Nothing to Disclose Mike Spektor, MD, New Haven, CT (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To identify emergency musculoskeletal imaging cases where a finding in a specific area requires additional imaging to complete the diagnosisTo identify emergency thoracic, abdominal and pelvic imaging cases where a finding in a specific area requires additional imaging to complete the diagnosisTo identify emergency neurological imaging cases where a finding in a specific area requires additional imaging to complete the diagnosis TABLE OF CONTENTS/OUTLINE Using a quiz format, for each item, the imaging scenario will be presented and the viewer will be asked to choose the next appropriate test to complete the diagnosis:Musculoskeletal Isolated medial or posterior malleolus fracture Isolated greater trochanter fracture Calcaneal fracture(s) Pediatric bucket handle/corner fracture Hypertrophic osteoarthropathy Subtrochanteric femoral fractureTorso Peripheral wedge shaped pulmonary opacity on non-contrast CT imaging Young male with lung masses Isolated right varicocele Hyperenhancement of Segment IV of the liverNeurological Spinal lesion(s) on MRI Stroke in multiple vascular territories Stroke in two separate vascular territories High medial temporal lobe T2 weighted signal on MRI ER115-ED-X More than Appendicitis: Imaging and Differential Diagnosis of Acute Right Lower Quadrant Pain All Day Room: ER Community, Learning Center Participants Christopher J. Steel, MD, Travis AFB, CA (Abstract Co-Author) Nothing to Disclose Trevor A. Thompson, MD, Columbus, OH (Abstract Co-Author) Nothing to Disclose Dell P. Dunn, MD, Newton, MA (Abstract Co-Author) Nothing to Disclose Valerie Hostetler, MD, Travis AFB, CA (Presenter) Nothing to Disclose TEACHING POINTS The purpose of this exhibit is: 1. To review the ACR appropriateness criteria of imaging for right lower quadrant pain in different patient populations. 2. Discuss utility of intravenous, oral, and rectal contrast in imaging for acute abdominal pain. 3. Case review of abdominal and pelvic disease that often result in acute right lower quadrant pain. TABLE OF CONTENTS/OUTLINE Introduction ACR appropriateness criteria of imaging for right lower quadrant pain in different patient populations Use of intravenous, oral, and rectal contrast in imaging for acute abdominal pain Comprehensive case review of abdominal and pelvic disease resulting in acute right lower quadrant pain -Bowel -Omentum/Mesentery -Urinary -Uterine/Ovarian -Vascular -Musculoskeletal Summary ER116-ED-X Urinary Bladder Injury: Pearls and Pitfalls All Day Room: ER Community, Learning Center Participants Krystal Archer-Arroyo, MD, Baltimore, MD (Presenter) Nothing to Disclose Robin B. Levenson, MD, Newton, MA (Abstract Co-Author) Nothing to Disclose Stuart E. Mirvis, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Review the types of bladder injury and associated findings on cystography, computed tomography (CT) and CT cystography.2. Discuss the most appropriate imaging technique(s) to assess for urinary bladder injury.3. Demonstrate potential pitfalls in urinary bladder injury evaluation to help avoid misdiagnosis. TABLE OF CONTENTS/OUTLINE I. Introduction II. AnatomyA. MaleB. Female III. Mechanisms of injuryA. BluntB. PenetratingC. Spontaneous IV. Classification Systems A.American Association for the Surgery of Trauma (AAST)-Organ Injury Scale B. Societe Internationale D'Urologie V. Imaging evaluation:A. CystographyB. Computed Tomography C. CT cystography VI. Types of Injury, including imaging findings and treatment/managementA. ContusionB. Interstitial injuryC. Intraperitoneal ruptureD. Extraperitoneal rupture i. Simple ii. ComplexE. CombinedVII. Pitfalls, including but not limited to:A. Intraluminal blood clot in the bladder obscuring bladder injuryB. Penetrating pelvic trauma with rectal injury mimicking bladder injuryC. Arterial bleed mimic VIII. Summary IX. References Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Stuart E. Mirvis, MD - 2015 Honored Educator ER117-ED-X Update and Review of Dual-Energy CT Clinical Applications of the Urolithiasis All Day Room: ER Community, Learning Center FDA Discussions may include off-label uses. Participants Xiaohu Li, MD, Hefei, China (Presenter) Nothing to Disclose Yongqiang Yu, MD, Hefei, China (Abstract Co-Author) Nothing to Disclose TEACHING POINTS • Review DECT technique and discuss clinically specific renal protocols • Apply various DECT imaging displays and advance post-processing techniques to differentiate urinary stone composition and use Ultra-low-dose to find urinary stone TABLE OF CONTENTS/OUTLINE Dual energy implies at two different kV(80KV,140KV) levels simultaneously., which allows characterizing the imaged tissue or material.Imaging review of DECT protocols used to characterize different urinary stone composition: v UA stone. with high accuracy. Urinary calculi can be effectively evaluated at Ultra-lowdose with use of lower tube voltages and the adaptive statistical iterative reconstruction algorithm not only in vitro but also in vivo.DECT provides diverse, easily utilized series that aid in more accurate characterization of diffe ER118-ED-X The Use of Split Bolus Single Pass Whole Body CT in the Severely Injured Trauma Patient All Day Room: ER Community, Learning Center Participants Vincent Leung, MBCHB, Stoke-On-Trent, United Kingdom (Presenter) Nothing to Disclose Sahithi Nishtala, MBBS, Stoke On Trent, United Kingdom (Abstract Co-Author) Nothing to Disclose Hefin Jones, FRCR, Birmingham, United Kingdom (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Split bolus contrast CT provides angiographic and venous phase imaging with a single pass of the CT gantry. Following this exhibit the learner should: Have the technical knowledge to implement a split bolus protocol. Understand the advantages and disadvantages of split bolus CT compared to traditional multi-pass trauma CT Begin to recognise the appearance of solid organ and vascular injury on split bolus CT TABLE OF CONTENTS/OUTLINE Physiology behind a split bolus CT protocol Technical requirements for split bolus CT An example split bolus CT protocol: Contrast regime and timing Advantages of split bolus CT Disadvantages of split bolus CT Sample trauma cases performed with split bolus CT including normal appearances, solid organ injury and vascular injury ER119-ED-X Hip Dislocations in the Emergency Department: What the Orthopedic Surgeon Needs to Know All Day Room: ER Community, Learning Center Awards Cum Laude Participants Jacob C. Mandell, MD, Waltham, MA (Presenter) Nothing to Disclose Richard A. Marshall, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Michael Weaver, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Mitchell A. Harris, PhD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG Bharti Khurana, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To understand the anatomy of the hip joint and how the mechanism of hip dislocation leads to certain patterns of osseous and soft tissue injury. To understand the types of hip fracture dislocations, associated injuries, and sequelae. To describe key imaging findings that the surgeon needs to know upon initial presentation and in the post-reduction setting. TABLE OF CONTENTS/OUTLINE Review the relevant anatomy of the hip joint using illustrations and radiological images. Demonstrate the different types of hip dislocations, associated injuries, and complications on various imaging modalities. Describe and illustrate the classification systems of hip fracture dislocation most commonly used by orthopedic surgeons, in a simplified manner. Describe key imaging findings that the orthopedic surgeon needs to know to properly manage a hip dislocation upon its initial presentation and on post reduction imaging. Review the imaging findings of dislocated hip arthroplasty. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Bharti Khurana, MD - 2014 Honored Educator Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ER120-ED-X Imaging Overlap in Inflammatory and Neoplastic Abdominopelvic Conditions in the Emergency Setting All Day Room: ER Community, Learning Center Participants Tarek N. Hanna, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Gayatri Joshi, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Jacqueline Junn, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Tadeusz Ciszak, MD, Atlanta, GA (Presenter) Nothing to Disclose Keith D. Herr, MD, San Francisco, CA (Abstract Co-Author) Nothing to Disclose Jamlik-Omari Johnson, MD, Atlanta, GA (Abstract Co-Author) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press TEACHING POINTS 1. Review emergent abdominopelvic inflammatory or infectious conditions that have imaging overlap with neoplasm. 2. Recognize morphologic patterns and imaging features favoring neoplasm versus infection/inflammation. 3. Be comfortable with the spectrum of imaging overlap, understanding that certain cases will be equivocal. Review management of these equivocal cases. 4. Learn appropriate imaging follow-up for both neoplastic and inflammatory/infectious conditions. TABLE OF CONTENTS/OUTLINE Emergent abdominopelvic inflammatory or infectious conditions, which have overlapping imaging features with neoplasm will be presented in tandem, with an emphasis on imaging features favoring one condition or the other. These conditions include esophagitis/esophageal cancer, gastritis/gastric adenocarcinoma, colitis/colon cancer, appendicitis/mucinous tumor or carcinoid, pancreatitis/pancreatic adenocarcinoma, cholecystitis/gallbladder carcinoma, cholangitis/cholangiocarcinoma, hepatitis/infiltrative hepatocellular carcinoma, focal pyelonephritis/renal cell carcinoma or renal lymphoma, ureteritis/transitional cell carcinoma, cystitis/transitional cell carcinoma, mesenteric fat stranding/infiltrative lymphoma or peritoneal carcinomatosis, and aortitis/lymphoma. Additionally, appropriate imaging follow-up will be addressed for further elucidation of these conditions. ER121-ED-X Volleyball Injuries: Musculoskeletal Trauma of the Extremities and the Spine All Day Room: ER Community, Learning Center Participants Daichi Hayashi, MBBS, PhD, Bridgeport, CT (Presenter) Nothing to Disclose Akira M. Murakami, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Ali Guermazi, MD, PhD, Boston, MA (Abstract Co-Author) President, Boston Imaging Core Lab, LLC Research Consultant, Merck KgaA Research Consultant, Sanofi-Aventis Group Research Consultant, TissueGene, Inc Research Consultant, OrthoTrophic Research Consultant, AstraZeneca PLC Frank W. Roemer, MD, Boston, MA (Abstract Co-Author) Chief Medical Officer, Boston Imaging Core Lab LLC; Research Director, Boston Imaging Core Lab LLC; Shareholder, Boston Imaging Core Lab LLC; ; Yogesh Kumar, MD, Bridgeport, CT (Abstract Co-Author) Nothing to Disclose Michel D. Crema, MD, Boston, MA (Abstract Co-Author) Shareholder, Boston Imaging Core Lab, LLC TEACHING POINTS To describe acute trauma and chronic overuse injuries in volleyball players at their most common sites and to discuss the available imaging methods for diagnosis and detailed assessment focusing on therapeutic relevance To illustrate and discuss the mechanisms of injuries in volleyball players TABLE OF CONTENTS/OUTLINE 1. Epidemiology of volleyball injuries 2. Pictorial review of characteristic injuries in volleyball players, including the following pathologies and mechanism of injury:Lower extremities: Ankle – inversion sprain, talofibular ligament tear, calcaneofibular ligament tear Knee – jumper’s knee, anterior cruciate ligament tear, medial collateral ligament tearUpper extremities: Shoulder – internal and external impingement resulting in rotator cuff injury, labral tear and muscle denervation Hand – tear of collateral ligaments at the interphalangeal joints of fingers, Mallet fingerBack and spine: spondylolysis, stress-related bone marrow edema of pars interarticularis, paravertebral muscle strainInjuries in youth and children: tibial tuberosity apophysitis3. Role of multimodality imaging for treatment decisions and conclusion Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Ali Guermazi, MD, PhD - 2012 Honored Educator ER122-ED-X A Hazard at Home? Facilitating the Safe Imaging of Repatriated Patients with Confirmed Ebola Virus Disease All Day Room: ER Community, Learning Center Participants Josephine E. Bretherton, MA, MBBS, London, United Kingdom (Presenter) Nothing to Disclose Gary Cross, MBBCHIR, London, United Kingdom (Abstract Co-Author) Nothing to Disclose Fiona Lam, MBBS, London, United Kingdom (Abstract Co-Author) Nothing to Disclose Carla Papagiorcopulo, MD, London, United Kingdom (Abstract Co-Author) Nothing to Disclose Dylan R. Tsukagoshi, MBBS, London, United Kingdom (Abstract Co-Author) Nothing to Disclose TEACHING POINTS By viewing this exhibit, the reader will be able to:1. Gain insight into the standard operating protocol developed in our institution for the safe diagnostic imaging of contagious patients on our High Level Isolation Unit, specifically with regard to X-ray and ultrasound imaging of patients with confirmed Ebola Virus Disease.2. Consider the technical limitations and challenges of performing imaging investigations on this patient cohort.3. Share the lessons learned when the protocol was exercised, and the plans we made to prepare for a wider outbreak. TABLE OF CONTENTS/OUTLINE 1. Background: Ebola Virus Disease in Africa and the international response2. The High Level Isolation Unit at our institution: history, description, photographs and floorplan3. Role of imaging in patients with confirmed Ebola Virus Disease4. Scope for imaging of patients with confirmed Ebola Virus Disease5. Outline of departmental protocol created in anticipation of the first patient's arrival (X-ray and limited ultrasound)6. Lessons learned from the first admission and subsequent development of protocol for portable ultrasound imaging7. Planning for increased numbers of patients in isolation (overflow unit) and for cases no longer considered infectious ER123-ED-X Twist and Shout: A Resident's Guide to Recognizing Volvulus and Torsion in Organs across the Body All Day Room: ER Community, Learning Center Participants Heather Schultz, MD, Santa Barbara, CA (Presenter) Nothing to Disclose Maximilian Cho, MD, Santa Barbara, CA (Abstract Co-Author) Nothing to Disclose Tara A. Bloom, MD, Santa Barbara, CA (Abstract Co-Author) Nothing to Disclose Bernard Chow, MD, Santa Barbara, CA (Abstract Co-Author) Nothing to Disclose Christopher D. Kuzminski, MD, Charlottesville, VA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Torsion consists of a structure twisting on a pedicle around its axis. This serious condition can lead to vascular constriction within a twisted pedicle and result in visceral ischemia. The gastrointestinal tract is a well-recognized site of volvulus. Abnormally long or lax peritoneal attachments can predispose organs to hypermobility and eventual twisting. Ovarian and testicular anatomy similarly prediposes these organs to torsion. Although less frequent, torsion can occur in other organs, including the heart and lungs. Since clinical presentations of torsion may be nonspecific, imaging often plays a crucial role in diagnosis and management. Knowledge of specific imaging findings for both common and rare forms of torsion is critical for diagnosis and guides timely intervention. TABLE OF CONTENTS/OUTLINE This exhibit will provide a thorough review of intra-abdominal volvulus and torsion as well discuss less common extra-abdominal correlates. The incidence, risk factors, pathophysiology, imaging findings, complications and management will be presented in a case-based format. Unique institutional examples include volvulus of the stomach, gallbladder, cecum and sigmoid colon, as well as cases of ovarian, testicular and lobar lung torsion. Additionally, examples of cardiac, splenic and renal torsion will be presented to supplement our institution's cases. ER124-ED-X Beyond Appendicitis: Ultrasound Findings of Acute Bowel Pathology All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Jihee Choe, MD, Boston, MA (Presenter) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aya Michaels, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Asha Sarma, MD, Jamaica Plain, MA (Abstract Co-Author) Nothing to Disclose Urvi P. Fulwadhva, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG TEACHING POINTS 1) Bowel pathology is a common unexpected finding on routine pelvic and abdomen ultrasound; therefore, familiarity with characteristic ultrasound features of bowel pathologies is essential. 2) Graded compression scan technique is an important component of ultrasound evaluation of the bowel and can significantly improve the ability to identify bowel pathology. 3) Real time sonographic assessment of wall thickening and bowel motility provides important clues to underlying bowel pathology. TABLE OF CONTENTS/OUTLINE 1) Basic ultrasound scan technique for bowel evaluation.2) Anatomic review of the ultrasound appearance of normal small and large bowel.3) Case based review of the ultrasound features of acute bowel abnormalities including appendicitis, enteritis, colitis, bowel obstruction, ileus, and bowel ischemia.4) Common mimics and diagnostic pitfalls in ultrasound evaluation of the bowel. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ER125-ED-X It's a Bleeder! Traumatic Intracranial Hemorrhage and Associated Complications All Day Room: ER Community, Learning Center Participants Neha Gowali, MD, Morristown, NJ (Presenter) Nothing to Disclose Elana B. Smith, MD, Denver, CO (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. 2. 3. Recognize the types of traumatic intracranial hemorrhage. Review the complications associated with traumatic intracranial hemorrhage. Discuss imaging pitfalls that may be misinterpreted as intracranial hemorrhage. TABLE OF CONTENTS/OUTLINE I. Introduction II. Types of Hemorrhage A. Epidural Hematoma – Arterial and Venous B. Subdural Hematoma C. Subarachnoid hemorrhage D. Intraventricular Hemorrhage E. Parenchymal hemorrhage/contusion F. Diffuse Axonal Injury III. Special Cases A. Penetrating Trauma B. Non-accidental Trauma IV. Pitfalls/Mimics of hemorrhage A. Pseudosubarachnoid hemorrhage B. Failure of FLAIR suppression C. Contrast staining D. Calcifications V. Complications A. Herniation Patterns 1. Uncal 2. Descending Transtentorial 3. Ascending Transtentorial 4. Subfalcine 5. External 6. Cerebellar Tonsillar B. Secondary Hemorrhage C. Infarct D. Encephalomalacia/Gliosis VI. Summary ER126-ED-X Small Object, Big Trouble: Dangerous Foreign Body in Adults All Day Room: ER Community, Learning Center Participants Wei Wang, Beijing, China (Presenter) Nothing to Disclose Xiaoying Wang, MD, Beijing, China (Abstract Co-Author) Nothing to Disclose Xiaoyu Hu, Beijing, China (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Discuss the role of CT in the diagnosis and evaluation of complications for foreign body in adults. Describe the characteristics of foreign bodies that may cause trouble in adults. Recognize the critical situations that may require aggressive treatment. TABLE OF CONTENTS/OUTLINE □Predisposed patients & Clinical history□Types of foreign bodies in adults–Common types–The trouble ones□Imaging approach –Plain film & CT–The importance of CT •Existence, location, characteristics, complications •Fast and accurate □More cautions, prefer CT– Special shape –Special composition –Special location –Special history □Treatment ER127-ED-X Imaging Diagnosis of Various Appendiceal Disease: Beyond Acute Appendicitis All Day Room: ER Community, Learning Center Participants Akitoshi Inoue, MD, Shiga, Japan (Presenter) Nothing to Disclose Shinichi Ota, MD,PhD, Otsu, Japan (Abstract Co-Author) Nothing to Disclose Akira Furukawa, MD, PhD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Takayasu Iwai, Omihachiman, Japan (Abstract Co-Author) Nothing to Disclose Ryo Kuwahara, MD, Kyoto, Japan (Abstract Co-Author) Nothing to Disclose Shigetaka Sato, MD, Otsu, Japan (Abstract Co-Author) Nothing to Disclose Kenji Furuichi, Osaka, Japan (Abstract Co-Author) Nothing to Disclose Michio Yamasaki, MD, Ritto, Japan (Abstract Co-Author) Nothing to Disclose Norihisa Nitta, MD, Kyoto, Japan (Abstract Co-Author) Nothing to Disclose Kiyoshi Murata, MD, Otsu, Japan (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Various pathologic conditions including inflammatory processes may arise in the appendix. Besides, other diseases required to be distinguished from acute appendicitis may also arise in and around the appendix. Radiologist should be familiar with the modalities and pathophysiology of the appendceal disease.The aims of this presentation include the following:1) To describe anatomy of the appendix and imaging modalities for appendiceal disease2) To review many variations and differential diagnoses of acute appendicitis3) To describe other diseases of the appendix besides appendicitis TABLE OF CONTENTS/OUTLINE 1, Anatomy, variation, and anomaly of the appendix2, Imaging modalities for diagnosis of appendicitis3, Acute Appendicitis 3-1, Cause 3-2, Severity 3-3, Complications 3-3, Treatment 3-4, Atypical appendicitis 3-5, Differential diagnosis4, Beyond appendicitis 4-1, Appendiceal diverticulum Diverticulitis, acute appendicitis with diverticulum 4-2, Intussusception Caused by acute appendicitis, adenocarcinoma 4-3, Neoplasms Benign: appendiceal neuromak, endometriosis Malignant: carcinoid, mucinous cyst adenoma, adenocarcinoma, lymphoma 4-4, Miscellaneous Small bowel obstruction due to adhesive appendix5, Summary ER128-ED-X Cross-Sectional Imaging Spectrum of Uterine and Fallopian Tube Emergencies All Day Room: ER Community, Learning Center Participants Ameya J. Baxi, MBBS, DMRD, San Antonio, TX (Presenter) Nothing to Disclose Vijayanadh Ojili, MD, San Antonio, TX (Abstract Co-Author) Nothing to Disclose Dhanashree Rajderkar, MD, Gainesville, FL (Abstract Co-Author) Nothing to Disclose Arpit M. Nagar, MBBS, Columbus, OH (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To describe the imaging manifestations of uterine and fallopian tube emergencies and discuss the clinical implications of specific imaging findings.2. To discuss the role of imaging and image-guided interventions in the management of these patients. TABLE OF CONTENTS/OUTLINE 1. Introduction, etiopathogenesis and clinical presentation of uterine and fallopian tube emergencies.2. Role of cross-sectional imaging modalities (particularly MDCT)3. Imaging spectrum of uterine and fallopian tube emergencies. A. Uterus (gas gangrene of the uterus, prolapsing fibroid, red degeneration of fibroids, uterine perforation from a wide variety of causes etc.) B. Fallopian tube (tubal torsion, tubo-ovarian abscess, ruptured tubal ectopic etc.) C. Miscellaneous (uterine AVM, uterine artery aneurysm/pseudoaneurysm, uterine rupture with abscess, fistulas etc.) ER129-ED-X Ultrasound of Right Upper Quadrant Abdominal Pain: The Gallbladder is Not Always to Blame! All Day Room: ER Community, Learning Center Awards Certificate of Merit Identified for RadioGraphics Participants Gayatri Joshi, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Kevin A. Crawford, MD, Chattanooga, TN (Presenter) Nothing to Disclose Tarek N. Hanna, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Keith D. Herr, MD, San Francisco, CA (Abstract Co-Author) Nothing to Disclose Kathryn A. Robinson, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Nirvikar Dahiya, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Review the causes of right upper quadrant pain using an organ-system approach Illustrate the sonographic appearance of select pathologies from each organ-system with multimodality imaging correlates Discuss the pathophysiology and management of these entities as relevant to the radiologist TABLE OF CONTENTS/OUTLINE Though acute cholecystitis is the most common diagnosable cause for right upper quadrant (RUQ) pain presenting in the Emergency Department, over 1/3 of these patients have RUQ pain attributable to other causes. This exhibit is a systematic organbased review of etiologies for RUQ pain in a case-based format. The cases shown will demonstrate gallbladder/biliary, pancreatic, hepatic, gastrointestinal, renal, adrenal, vascular, and thoracic etiologies for RUQ pain. As ultrasound (US) is the modality of choice for evaluation of RUQ abdominal pain in the Emergency setting, each entity will be illustrated with initial sonographic appearance followed by multimodality imaging correlates and a short discussion of pathophysiology and management of these entities as relevant to the radiologist. ER130-ED-X Is That A Fracture? Differentiating Spine Fractures From Their Mimics All Day Room: ER Community, Learning Center Participants Thomas F. Flood, MD, PhD, Aurora, CO (Abstract Co-Author) Nothing to Disclose Elana B. Smith, MD, Denver, CO (Presenter) Nothing to Disclose TEACHING POINTS 1. Demonstrate developmental variants and disease processes that can simulate spine fractures. 2. Recognize imaging artifacts that may simulate spine fractures and how they can be distinguished from fractures. 3. Review the pathogenesis/technical factors that result in these spine fracture mimics. TABLE OF CONTENTS/OUTLINE Spine fracture mimics will be directly compared and contrasted to similar appearing fractures. The information will be presented in quiz format. Cases will include: I. Normal Variants A. Os odontoidium and os terminale B. Butterfly vertebrae C. Limbus body D. Neural arch clefts E. Unfused apophysis F. Venous channels G. Physiologic wedging H. Trapezoidal L5 vertebral body I. Transverse foramen defect II. Pathologic Processes A. Schmorl node B. Osteophytes C. Scheuerman’s disease D. Kyphosis E. Spondylolysis III. Technical A. Mach lines B. Motion artifact C. Beam hardening artifact D. Parallax ER131-ED-X Detection and Management of FISHBONE Ingestion All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants SHOTA TAKEHARA, Okinawa, Japan (Presenter) Nothing to Disclose Masahiro Okada, MD, Nishihara-Cho, Japan (Abstract Co-Author) Nothing to Disclose Maho Tsubakimoto, MD, Nishihara, Japan (Abstract Co-Author) Nothing to Disclose Tsuneo Yamashiro, MD, Nishihara, Japan (Abstract Co-Author) Research Grant, Toshiba Corporation Yuko Iraha, Nishihara-cho, Japan (Abstract Co-Author) Nothing to Disclose Sadayuki Murayama, MD, PhD, Nishihara-Cho, Japan (Abstract Co-Author) Research Grant, Toshiba Corporation Yurika Agarie, MD, Okinawa, Japan (Abstract Co-Author) Nothing to Disclose Kimei Azama, Nishihara City, Japan (Abstract Co-Author) Nothing to Disclose Nanae Tsuchiya, Okinawa, Japan (Abstract Co-Author) Nothing to Disclose Makoto Takara, Okinawa, Japan (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The purposes of this exhibit are:1. To review the findings of plain X-ray, CT and US in patients with FISHBONE.2. To discuss the relationship between clinical and image findings in patients with FISHBONE, including emergency (perforation and abscess, etc).3. To explain the utility of CT for the complications associated with FISHBONE.This review article is provided for every radiology resident/ fellow. TABLE OF CONTENTS/OUTLINE 1. Signs and symptoms of FISHBONE; including risk factors of FISHBONE ingestion; acute inflammation type and chronic status 2. CT applications for acute abdominal diseases 3. X-ray, CT and US findings of FISHBONE ingestiona) X-ray; linear calcification, b) CT; linear high density, c) US; linear high echoic shadow4. When FISHBONE is inserted into different locations, such asa) Pharynx, b) Esophagus, c) Stomach, d) Duodenum, e) Small intestine, f) Colon, g) Passing from stomach to liver5. Treatment strategy corresponding to the location and symptom of FISHBONEa) Surgical resection, b) Endoscopic resection c) Laparoscopic resection, d) Abscess drainage, e) Conservative management6. Perforation from GI tract 7. The utility of the workstation (reconstructed CT images) 8. Pitfalls of FISHBONE imaging 9. Quizzes of CT imaging for acute abdomen ER132-ED-X First Trimester Emergencies: What the Radiologist Needs to Know and What the Clinician Wants to Know All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Catherine Phillips, MD, Boston, MA (Presenter) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Elizabeth Ginsburg, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG Bharti Khurana, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. First trimester embryologic development is a stepwise process and knowledge of the findings suspicious for pregnancy failure is critical.2. Complications of early pregnancy include ectopic implantation, subchorionic hematoma, ectopic implantation, pregnancy failure, retained productions of conception, and gestational trophoblastic disease.3. To provide meaningful interpretation and improve the value of image interpretation, radiologists must understand what the ER and OB/GYN physicians need to know to guide effective treatment of first trimester emergencies. TABLE OF CONTENTS/OUTLINE 1. The anatomy of the developing embryo including illustrations, ultrasound, and MRI examples.2. Radiologic appearance and management of early pregnancy complications, including ectopic pregnancy, gestational trophoblastic disease, subchorionic hematoma, retained products of conception, and pregnancy failure.3. Frequently seen complications of pregnancy associated with assisted reproductive techniques.4. Imaging appearance of common pitfalls and mimics in imaging early pregnancy, including trauma, hemorrhagic ovarian cysts, and pre-existing lesions such as pedunculated fibroids. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator Bharti Khurana, MD - 2014 Honored Educator ER133-ED-X The Many Faces of Ectopic Pregnancy All Day Room: ER Community, Learning Center Participants Arash Bedayat, MD, Worcester, MA (Presenter) Nothing to Disclose Byron Y. Chen, MD, Worcester, MA (Abstract Co-Author) Nothing to Disclose Carolyn S. Dupuis, MD, Worcester, MA (Abstract Co-Author) Nothing to Disclose William Parkhurst, MD, Jefferson, MA (Abstract Co-Author) Nothing to Disclose Michael J. Caruso, DO,BS, Worcester, MA (Abstract Co-Author) Nothing to Disclose Hao S. Lo, MD, Worcester, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Review the typical and atypical imaging findings of ectopic pregnancy. 2. Discuss the imaging pitfalls and clinical complications associated with the diagnosis. TABLE OF CONTENTS/OUTLINE Knowledge of the different manifestations of ectopic pregnancy and differentiation of ectopic pregnancy from other causes of first trimester abdominal pain or bleeding (i.e., intrauterine pregnancy, intrauterine fetal demise and molar pregnancy) is critical in the emergency setting. Ectopic pregnancy is the most common cause of pregnancy-related mortality in the first trimester. Key imaging findings and pertinent recommendations to include in the radiology report will be discussed in this educational exhibit. ER134-ED-X Secondarily Caused Acute Abdomen: What is the "True" Causative, but Covert Disease in the Patient? All Day Room: ER Community, Learning Center Participants Maho Tsubakimoto, MD, Nishihara, Japan (Presenter) Nothing to Disclose Tsuneo Yamashiro, MD, Nishihara, Japan (Abstract Co-Author) Research Grant, Toshiba Corporation Nanae Tsuchiya, Okinawa, Japan (Abstract Co-Author) Nothing to Disclose Masahiro Okada, MD, Nishihara-Cho, Japan (Abstract Co-Author) Nothing to Disclose Sadayuki Murayama, MD, PhD, Nishihara-Cho, Japan (Abstract Co-Author) Research Grant, Toshiba Corporation TEACHING POINTS Although acute abdomens are very common for radiologists, we rarely encounter acute abdomens secondarily caused by unexpected, covert diseases in daily practice. The purpose of this exhibit is to introduce these rare acute abdominal conditions with actual CT images. TABLE OF CONTENTS/OUTLINE Classification of the etiology Imaging findings and details of cases from our institutions in a quiz format. Endocrine abnormality Acute pancreatitis due to parathyroid adenoma Jejunum perforation due to pyloric gastrinoma = Zollinger-Ellison Syndrome Megacolon with severe constipation in multiple endocrine neoplasia type 2bAutoimmune disease Severe enteritis due to systemic lupus erythematosus Bilateral adrenal infarction due to antiphospholipid antibody syndrome Intestinal bleeding due to polyarteritis nodosa Enteritis due to Henoch–Schönlein purpuraInfection Intestinal obstruction by anisakiasis Intestinal strongyloidiasis coinfected with human T-lymphotropic virus type 1Foreign body Liver abscess due to fish bone migration Pelvic actinomycosis due to an intrauterine device Esophageal perforation by a press-through packOther Renal vein thrombosis due to nephrotic syndrome Bowel obstruction and liver subcapsular hematoma due to heterotopic endometriosis Bowel obstruction by a gallstone ER135-ED-X Diverticulosis Stem-to-Stern: A New Look at an Old Disease with Emphasis on Diagnosis and Treatment of Complications All Day Room: ER Community, Learning Center Participants Jessica Wen, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Satomi Kawamoto, MD, Laurel, MD (Abstract Co-Author) Nothing to Disclose Margaret Fynes, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Richard M. Fleming, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Elliot K. Fishman, MD, Baltimore, MD (Abstract Co-Author) Institutional Grant support, Siemens AG; Institutional Grant support, General Electric Company; Pamela T. Johnson, MD, Baltimore, MD (Presenter) Consultant, National Decision Support Company Franco Verde, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Diverticular disease can affect any gastrointestinal segment from esophagus to the distal colon. Radiologists must be cognizant of potential complications of diverticulosis in each anatomic segment. This exhibit reviews: Pathophysiology of diverticulosis Classification including rare forms (meckels, appendiceal) CT technique for optimal evaluation CT findings in setting of complications Management of complications TABLE OF CONTENTS/OUTLINE Background Pathophysiology Classification Esophageal Gastric Duodenal Jejunal Meckels Ileocecal Appendiceal Colonic Imaging Fluoroscopy CT protocols tailored to suspected complications PO and IV contrast for inflammation water soluble PO contrast if perforation suspected neutral/no PO if GI bleeding optimal timing delay to avoid pseudothrombus of mesenteric veins MPRs facilitate identification of complications (mesenteric inflammation, hemorrhage)Complications Dysphagia Aspiration Bacterial overgrowth Obstruction/inflammation Perforation Abscess (subserosal, peritoneal, hepatic) Septic thrombophlebitis Hemorrhage Bladder/vaginal fistulaTreatment Conservative management Abscess drainage Surgical resection Embolization of active bleeding Anticoagulation for septic thrombophlebitis Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Pamela T. Johnson, MD - 2016 Honored Educator Elliot K. Fishman, MD - 2012 Honored Educator Elliot K. Fishman, MD - 2014 Honored Educator Elliot K. Fishman, MD - 2016 Honored Educator ER136-ED-X No Way Out: Causes of Duodenal and Gastric Outlet Obstruction All Day Room: ER Community, Learning Center Awards Identified for RadioGraphics Participants Kris Tantillo, MD, Bronx, NY (Presenter) Nothing to Disclose Benjamin Taragin, MD, Teaneck, NJ (Abstract Co-Author) Medical Advisory Board, Carestream Health, Inc Meir H. Scheinfeld, MD, PhD, Bronx, NY (Abstract Co-Author) Nothing to Disclose Victoria Chernyak, MD, Bronx, NY (Abstract Co-Author) Nothing to Disclose Alla M. Rozenblit, MD, Bronx, NY (Abstract Co-Author) Nothing to Disclose Robert J. Dym, MD, Bronx, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The purpose of this exhibit is to:1. Provide an image rich review of common and uncommon causes of duodenal and gastric outlet obstruction, providing classic imaging findings when appropriate, which may be encountered in ER setting2. Demonstrate the overlap in the imaging appearance of many of these conditions on radiography and upper GI series and to show how cross sectional imaging can be used for further evaluation TABLE OF CONTENTS/OUTLINE Outline: Pediatric/Congenital:Including cases such as pyloric stenosis, duodenal atresia, duodenal web/diaphragm, malrotation with midgut volvulus, annular pancreas, and obstructing duplication cyst Infectious/inflammatory:Including cases such as retroperitoneal fibrosis, peptic ulcer disease, Crohns stricture, duodenitis, and pancreatitis Neoplastic:Including cases such as gastric/duodenal mass, pancreatic mass, and colon mass Mechanical:Including cases such as Bouveret syndrome, gastric volvulus, gastroparesis, bezoar, SMA syndrome, gastric volvulus, post-traumatic/spontaneous duodenal hematoma, and iatrogenic/post-surgical ER137-ED-X Computed Tomography in Elderly Patients with Acute Abdominal Pain: What Surgeons Need to Know All Day Room: ER Community, Learning Center Participants Lourdes Del Campo, PhD, Madrid, Spain (Presenter) Nothing to Disclose Elena Ocon, MD, PhD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Pablo Rodriguez Carnero, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Ricardo Rivas Cuadrado, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Paloma Largo Flores, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Ramiro Pedro Campos Rivas, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Jose M. Munoz, Madrid, Spain (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Review the most frequent pathology in elderly patients with abdominal pain in the emergency room.Evaluate the imaging findings in computed tomography (CT) in common and uncommon abdominal pathology in elderly peopleDiscuss the principal imaging findings that influences the management and decision-making in these patients. TABLE OF CONTENTS/OUTLINE As the population in the world continues to age, it is frequent to find in the emergency room patients older than 80 years old presenting with acute abdominal pain.The most common diagnosis in this subset of patients includes small and large bowel obstruction, inflammatory-infectious diseases, bowel ischemia and infarction, vascular related emergency, perforation, neoplasm, appendicitis and hernias. Our institution attends a great number of patients older than 80 years old suffering abdominal pain in the emergency department. Abdominopelvic CT is the method of choice used in these patients. This poster shows the typical and atypical radiological findings to illustrate the most frequent conditions associated with acute abdominal pain, specially emphasizing on how the clinical or surgical management may be influenced by the imaging. Diagnosis was confirmed with final clinical diagnosis, surgical intervention and/or follow-up. ER138-ED-X IVC Trauma. What are We Missing? A Fresh Look and Proposal for a Comprehensive Location Based IVC Injury Grading All Day Room: ER Community, Learning Center Participants Razia Rehmani, MD, New York, NY (Presenter) Nothing to Disclose TEACHING POINTS What is the current AAST IVC injury grading? How can you improve it? TABLE OF CONTENTS/OUTLINE Introduction: IVC injuries although rare are associated with a high mortality rate. Inspite of the recent advances in imaging and surgical techniques, IVC trauma accounts for 25% of abdominal vascular trauma, of which more than a third of patients expire before reaching the hospital. About half of the patients who reach hospital expire within 48 hours. AAST qualifies IVC injury as a grade III or more. Penetrating wounds account for 85-95% of trauma to IVC and blunt abdominal trauma (BAT) accounts for only 310%.Role of Imaging: Key identifers of IVC injury on CECT include (1) irregular contour (2) retroperitoneal hematoma, (3) contrast extravasation. We propose a more systematic location based approach to grade IVC injuries; Grade 1 (Infrarenal), Grade 2 (Suprarenal/Infrahepatic) & Grade 3 (Suprahepatic/Retrohepatic). Suprarenal injuries usually result from BAT, whereas infrarenal are more often due to penetrating wounds with a better prognosis. Retrohepatic injuries are associated with other severe injuries and have a very high mortality rate and are often seen at laparotomy.Summary: Stakes are high when dealing with IVC injuries. A simplified location based approach such as ours can allow quick assessment and appropriate triage of these critical patients. ER139-ED-X Rectal Trauma: Current Concepts in Imaging Diagnosis and Management All Day Room: ER Community, Learning Center Participants Justin Holder, MD, Brooklyn, NY (Presenter) Nothing to Disclose Patrick J. Hammill, MD, Brooklyn, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Review the anatomy of the rectum and perirectal spaces, including regional arterial supply and venous drainage. Describe and demonstrate the spectrum of imaging findings seen with rectal injuries. Highlight pitfalls in imaging interpretation. Discuss management of rectal injuries, including surgical and nonoperative approaches. Demonstrate important imaging findings to guide trauma management. TABLE OF CONTENTS/OUTLINE Injuries to the rectum have become increasingly common with rises in urban violence, and considerable debate exists regarding their optimal treatment. This exhibit will review the rectal and anal canal anatomy and imaging appearance. A comprehensive spectrum of injuries found in blunt and penetrating rectal trauma will then be presented in a quiz format, which will include various grading scales used in clinical practice. The multiple management approaches to rectal injury will be highlighted, and emphasis will be placed on current controversies in operative and nonoperative practices. After reviewing the exhibit, the participant will be able to identify the imperative imaging findings that influence management decisions. ER140-ED-X High Energy Facial Fractures: Ten Key Points. A Systematic Approach for an Easy Diagnostic and Classification All Day Room: ER Community, Learning Center Participants Luis S. Cueto, MD, PhD, Sevilla, Spain (Presenter) Nothing to Disclose Daniela D. Martins-Romeo, MD, Seville, Spain (Abstract Co-Author) Nothing to Disclose Alejandro Garcia de la Oliva, MD, Sevilla, Spain (Abstract Co-Author) Nothing to Disclose Teresa Ruiz Garcia, MD, PhD, Sevilla, Spain (Abstract Co-Author) Nothing to Disclose Amparo Rivera, MD, Sevilla, Spain (Abstract Co-Author) Nothing to Disclose Esther Piriz, Sevilla, Spain (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Know the types of complex fractures of the face. Evaluate the structures affectec specifically in each type. Use of check list for a correct diagnosis. Exhibition of interactive cases. TABLE OF CONTENTS/OUTLINE Review of facial butresses system. Describe the face high energy fractures: Le Fort I, Le Fort II, Le Fort III and N.O.E. Fractures. Key structures affected in each fracture. CT protocols. The best views for evaluate them. Chek list for a easy, rapid and safe diagnostic. Synchronous skull and spine involvement. Presentation of cases problem. ER141-ED-X Torsion of Wandering Spleen: A Rare Cause of Acute Abdomen All Day Room: ER Community, Learning Center Participants Michele Porcu, MD, Cagliari, Italy (Presenter) Nothing to Disclose Giovanni M. Argiolas, MD, Monserrato, Italy (Abstract Co-Author) Nothing to Disclose Giovanna Demurtas, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose Grazia T. Bitti, MD, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose Paolo Siotto, MD, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose Luca Saba, MD, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose Stefano Cossa, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose Stefano Cossa, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Recognise the main radiological features of the torsion of wandering spleen. Distinguish this condition from other causes of acute abdomen. TABLE OF CONTENTS/OUTLINE Acute abdomen is one of the most frequent clinical syndromes in emergency department. The quick recognition of the etiology of this clinical pattern is of primary importance in order to correctly manage the patient and limit complications.Among the possible causes of acute abdomen, the torsion of not fixed organs (such as spleen, ovaries, omentum and testes) have always to be considered.The “wandering spleen” is a very rare condition, due to the absence or accentuated laxity of the spleen suspensory ligaments, in particular the gastrolienal and the lienorenal. This condition is more frequent in the paediatric and female population.The torsion of the vascular pedicle of the spleen on its longitudinal axis, with splenic ischemia and the onset of the acute abdomen syndrome, is one of the possible complications of this condition. ER142-ED-X MDCT Review of Intravenous Drug Abuse Complications All Day Room: ER Community, Learning Center Participants Franco Verde, MD, Baltimore, MD (Presenter) Nothing to Disclose Constantine Burgan, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Elliot K. Fishman, MD, Baltimore, MD (Abstract Co-Author) Institutional Grant support, Siemens AG; Institutional Grant support, General Electric Company; TEACHING POINTS Intravenous drug abuse is becoming an epidemic in the US Multiple complications can occur from simple cellulitis to large open wounds, vascular injury, and septic emboli. Radiologists must be aware of such complications and imaging findings for optimal patient care TABLE OF CONTENTS/OUTLINE A. Introduction Statistics on IV drug abuse in the US B. Role of imaging Extent of disease Benefits of MPR/3Ds C. Case examples of Cellulitis without abscess Cellulitis with abscess Cellulitis with ulceration Cellulitis with thrombophlebitis Chronic wounds Deep extension of abscess Arterial pseudoaneurysm Retained needles Septic emboli D. Management of complications Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Elliot K. Fishman, MD - 2012 Honored Educator Elliot K. Fishman, MD - 2014 Honored Educator Elliot K. Fishman, MD - 2016 Honored Educator ER143-ED-X A Tale of Two Ovaries: Cross-Sectional Imaging Spectrum of Ovarian Emergencies All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Ameya J. Baxi, MBBS, DMRD, San Antonio, TX (Presenter) Nothing to Disclose Arpit M. Nagar, MBBS, Columbus, OH (Abstract Co-Author) Nothing to Disclose Dhanashree Rajderkar, MD, Gainesville, FL (Abstract Co-Author) Nothing to Disclose Vijayanadh Ojili, MD, San Antonio, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To describe the imaging manifestations of ovarian emergencies and discuss the clinical implications of specific imaging findings.2. To discuss the role of imaging and image-guided interventions in the management of these patients.3. To highlight the usefulness of imaging in evaluating the rare systemic manifestations such as Anti-NMDA encephalitis, thyrotoxicosis, pulmonary embolism, congestive heart failure etc. which are associated with specific ovarian disorders. TABLE OF CONTENTS/OUTLINE Introduction, etiopathogenesis and clinical presentation of ovarian emergencies.Role of cross-sectional imaging modalities (particularly MDCT)Imaging spectrum of ovarian emergencies. Torsion (torsion of an otherwise normal ovary, teratoma, cysts and cystic neoplasm) Infections (oophoritis, tubo-ovarian abscess) Rupture (ruptured ovarian cyst with hemoperitoneum, ruptured teratoma with hemorrhage and chemical peritonitis, etc. Oncologic emergencies (peritoneal carcinomatosis with small bowel obstruction, hydronephrosis from mass effect etc.) Miscellaneous (ovarian vein thrombosis, gonadal AVM, ovarian hyperstimulation syndrome, Anti-NMDA receptor encephalitis due to ovarian teratoma) ER144-ED-X Is There Osteo? Magnetic Resonance Imaging (MRI) of the Neuropathic Foot for Suspected Osteomyelitis in the Emergency Department (ED) All Day Room: ER Community, Learning Center Participants Rosan Patel, MD, Ann Arbor, MI (Presenter) Nothing to Disclose Adam Wright, MD, Ann Arbor, MI (Abstract Co-Author) Nothing to Disclose Corrie M. Yablon, MD, Ann Arbor, MI (Abstract Co-Author) Nothing to Disclose Jon A. Jacobson, MD, Ann Arbor, MI (Abstract Co-Author) Consultant, BioClinica, Inc; Royalties, Reed Elsevier; ; ; Suzanne T. Chong, MD, Ann Arbor, MI (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Review the pathophysiology of osteomyelitis in the setting of neuropathic feet, implications for clinical management, and the recommended imaging tests for suspected osteomyelitis per ACR Appropriateness Criteria.2. Discuss MRI evaluation of the neuropathic foot for suspected osteomyelitis including key imaging findings, protocol optimized for streamlined interpretation in the ED, and potential imaging pitfalls.3. Reinforce the understanding of these concepts through the use of interactive, illustrative cases. TABLE OF CONTENTS/OUTLINE Cases from a quaternary care, academic teaching hospital with a Level 1 trauma center were reviewed for this exhibit. In patients who present to the ED with foot pain and skin ulcer in the setting of a neuropathic foot, the diagnosis of osteomyelitis can be clinically challenging. Initial radiographs are limited in sensitivity and MRI is often ordered to provide a more definitive diagnosis. We will discuss our MRI protocol for foot osteomyelitis streamlined for expedited interpretation through the ED, present cases to illustrate the spectrum of disease from reactive edema in neuropathic foot to frank osteomyelitis, and highlight imaging pitfalls for radiologists to avoid. Cases will be presented to reinforce and challenge the reader's understanding of this topic. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jon A. Jacobson, MD - 2012 Honored Educator ER145-ED-X Renal 911 - Renal Emergencies All Day Room: ER Community, Learning Center Awards Identified for RadioGraphics Participants Soumya Maddula, MD, New Hyde Park, NY (Presenter) Nothing to Disclose John J. Hines JR, MD, New Hyde Park, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To become aware of various disease processes that can present as acute renal emergencies, including neoplastic, vascular, infectious, iatrogenic, and obstructive causesTo become familiar with CT imaging findings of acute renal emergencies, and to develop accurate and reasonably specific diagnosis for such findings.To improve knowledge of proper CT protocol for various suspected renal diseases, including appropriate use of non IV-enhanced, arterial, nephrographic and urographic phases. TABLE OF CONTENTS/OUTLINE Review of CT protocol for various renal diseasesReview of Imaging findings/ Mimics Neoplasm a.Hemorrhagic cysts b. Hemorrhagic angiomyolipoma c. Hemorrhagic Renal Cell Carcinoma 2. Infection a. Xanthogranulomatous pyelonephritis b. Renal abscess c. Emphysematous pyelonephritis d. Fungus ball in collecting system 3. Obstruction (unusual causes) a. Steinstrasse b. Congenital causes- UPJ obstruction, retrocaval ureter c. Retroperitoneal micrometastases 4. Iatrogenic a. Post surgical bleeding b. Urinoma c. Pseudoaneurysm 5. Vascular a. Spontaneous and post-surgical infarction b. Renal artery aneurysm d. Renal Artery DissectionSummary ER146-ED-X Imaging Pitfalls in Pelvic Trauma All Day Room: ER Community, Learning Center Participants Carson A. Kisner, MD, Shreveport, LA (Presenter) Nothing to Disclose Guillermo P. Sangster, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Simon Long, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Justin W. Skweres, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Luis M. De Alba Padilla, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Alberto A. Simoncini, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Purpose/aim:Pelvic trauma injuries can range from benign to life threatening. Pelvic injuries are often associated with significant bleeding, concomitant internal injuries, and high mortality. In this setting, the role of the sonographic FAST scan and pelvic radiograph is suboptimal and commonly obscures severe internal injuries. Multidetector Computed Tomography (MDCT) plays an essential role in diagnosing and characterizing pelvic trauma. Adequate knowledge of typical and atypical MDCT imaging patterns is essential for a prompt and correct diagnosis to avoid diagnostic pitfalls and unnecessary surgical interventions. This educational review aims to highlight the limitations of evaluating pelvic injuries in isolation. Learning objectives: Emphasize the limitations in determining the extent of pelvic injuries if radiographs or sonography are used in isolation. Demonstrate the importance of active distention of the urinary bladder when evaluating urinary tract injuries. Highlight MDCT‘s role as the modality of choice for detection, characterization and pre-operative planning in hemodynamically stable patients with pelvic injuries. TABLE OF CONTENTS/OUTLINE Content organization: Skeletal Pelvic Injury Secondary injuries Genitourinary Gastrointestinal Vascular ER147-ED-X Taking Run-off CT Angiography to TASC - Acute Vascular Pathology and the Role of Imaging for the Emergency Radiologist All Day Room: ER Community, Learning Center Participants Yaseen Oweis, MD, MBA, Saint Louis, MO (Presenter) Nothing to Disclose Zachary J. Viets, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Yuntong Ma, St. Louis, MO (Abstract Co-Author) Nothing to Disclose Anup S. Shetty, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Review abdominopelvic and lower extremity vascular anatomy CT Protocols and techniques for specific indications in the emergency department TASC classification and its role in triaging the acute vascular emergency Review case examples of traumatic and nontraumatic vascular diseases in the acute setting TABLE OF CONTENTS/OUTLINE Role of imaging in acute vascular pathology in the Emergency Department Review of abdominopelvic and lower extremity vascular anatomy CT Protocols Arterial/Venous/Delayed series Out-running bolus and other pitfalls Review of TASC II Classification - TransAtlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease Clinical cases of emergent peripheral vascular conditions Traumatic Iatrogenic Accidental Peripheral vascular disease ‘Typical’ peripheral vascular disease Stenosis Occlusion Embolic Vasculitis Bypass grafts Thrombosis Infection Aneurysm Summary and take-home points ER148-ED-X Cross-Sectional Musculoskeletal Imaging in the Emergent Setting: Indications and Common Cases All Day Room: ER Community, Learning Center Participants Talentshia Vethanayagamony, MD, Bolingbrook, IL (Presenter) Nothing to Disclose Suraj Chandrasekar, MD, MS, Hoffman Estates, IL (Abstract Co-Author) Nothing to Disclose Rina Patel, MD, San Francisco, CA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To highlight the importance and utility of further imaging evaluation with cross sectional imaging including CT, MRI, and ultrasound in specific emergency room situations.2. To understand indications for cross sectional imaging in the emergent setting3. To understand CT and MR features of commonly encountered emergent MSK cases including commonly encountered mimics TABLE OF CONTENTS/OUTLINE Commonly encountered Scenarios in the Emergency Room1. Fracturesa. Pelvis - Discuss ACR recommendations for secondary imaging to detect occult fractures in the sacrum, hip, etc. - Examples of occult fracturesb. Knee - ACR recommendation for secondary imaging and examples of cases - tibial plateau fracture.c. Ankle2. Infectiona. septic joint - ACR recommendation for further evaluation - US and MRIb. Osteomyelitis - ACR recommendation - MRI3. Miscellaneous/Mimicsa. Tendon injury - Hamstring strain/tear on MRI presenting as hip pain - US diagnosis of triceps tear after fallb. HADD/CPPD - Mimicking infection/septic joint ER149-ED-X Myonecrosis: The Obscurity of Rhabdomyolysis All Day Room: ER Community, Learning Center Participants Simon Long, MD, Shreveport, LA (Presenter) Nothing to Disclose Jared R. Garrett, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Alberto A. Simoncini, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Guy T. Alexander, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose Gabriel H. Aguilar, MD, Buenos Aires, Argentina (Abstract Co-Author) Speaker, sanofi-aventis Group; Speaker, AbbVie Inc Guillermo P. Sangster, MD, Shreveport, LA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS PURPOSE/AIMThis educational exhibit identifies the spectrum of findings associated with different imaging modalities in rhabdomyolysis including radiography, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy.TEACHING POINTS Recognize the different modality-based imaging patterns in patients with rhabdomyolysis. Review radiologic, clinical, and laboratory findings of potential rhabdomyolysis mimics. TABLE OF CONTENTS/OUTLINE CONTENT ORGANIZATIONRhabdomyolysis has traditionally been a clinical diagnosis with healthcare providers utilizing historical context, physical exam, and laboratory data to arrive at a diagnosis. However, there are a plethora of imaging findings which can support a presumptive diagnosis while ruling out differentials. This exhibit seeks to review imaging findings associated with rhabdomyolysis using different modalities including radiographs, US, CT, MRI, and bone scintigraphy. ER150-ED-X Leg Veins Ultrasound and Pulmonary Artery CT Angiography for Deep Vein Thrombosis and Pulmonary Embolism Rule Out. When and How to Perform. When Not to Perform. What to Expect All Day Room: ER Community, Learning Center Participants Demosthenes D. Cokkinos, MD, Athens, Greece (Presenter) Speaker, Bracco Group Eleni Antypa, Athens, Greece (Abstract Co-Author) Nothing to Disclose Sofia Tsolaki, Athens, Greece (Abstract Co-Author) Nothing to Disclose Eleni Lazaridou, Athens, Greece (Abstract Co-Author) Nothing to Disclose Anastasia Anagnostopoulou, Athens, Greece (Abstract Co-Author) Nothing to Disclose Ploutarhos A Piperopoulos, MD, PhD, Athens, Greece (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To outline imaging guidelines for performing emergency ultrasound (US) of leg veins for deep vein thrombosis (DVT) rule out and CT pulmonary angiography (CTPA) in patients with suspected pulmonary embolism (PE). To study the place of these imaging modalities in appropriateness criteria after performing pre-test probability evaluation of Wells Score and D-dimer blood count. TABLE OF CONTENTS/OUTLINE Different chapters of the presentation include: Description of pre-test probability evaluation of Wells Score and D-dimer blood count according to guidelines before performing leg veins US and CTPA. Indications, technique description, findings, limitations, diagnostic value and pitfalls of leg veins US for DVT detection and CTPA technique for PE detection. Examples of clinical scenarios in which these imaging modalities are not indicated. Imaging examples of DVT and PE are presented and findings are explained. The questions of difficulty in performing US below the knee and reporting subsegmental branches PE are assessed. Dose reduction techniques for CTPA are also discussed. ER151-ED-X Acetabular Fractures: A Radiologic Review in Multiple Modalities Utilizing a Novel Teaching Approach with 3Dprinted Models All Day Room: ER Community, Learning Center Participants Scott Honowitz, MD, San Jose, CA (Presenter) Nothing to Disclose Ryan Chao, MD, San Jose, CA (Abstract Co-Author) Nothing to Disclose Jeffrey Tseng, MD, Menlo Park, CA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Important cause of morbidity and mortality following trauma. Two classification schemes include the more widely used JudetLetournel system and the modern CT-based Harris-Coupe system. Teaching this complex subject may be aided by the use of 3Dprinted models. TABLE OF CONTENTS/OUTLINE Normal acetabular anatomy. Fracture patterns in two classification systems with imaging pearls for both radiography and CT. Clinical significance of the fracture classifications. 3D-Printed models for educational purposes: Graphic comparisons of different acetabular fracture patterns in multiple modalities including radiography, CT 2D images, CT 3D reformations, and 3D printed models. If platform space is available at the RNSA exhibit, actual 3D-printed models will be displayed for inspection and manipulation by attendees. ER152-ED-X Nontraumatic Perforation in the Gastrointestinal Tract: CT Diagnosis and Its Differentiation All Day Room: ER Community, Learning Center Participants Nam Kyung Lee, MD, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Jeongmyeong Kim, MD, Pusan, Korea, Republic Of (Presenter) Nothing to Disclose Suk Kim, MD, Pusan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Ga Jin Han, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Sang Jeong Ahn, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Tae Un Kim, MD, Yangsan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To describe the CT features of various pathologic conditions causing gastointestinal perforation beyound trauma. To discuss the characteristic CT features to differentiate malignant from benign causes in the gastointestinal perforation. To differentiate gastrointestinal perforation requiring emergency surgery from balanced penumoperitoneum. TABLE OF CONTENTS/OUTLINE IntroductionVarious conditions causing nontrauamtic GI tract perforation1. Neoplastic conditions Adenocarcinoma GIST Metastasis Lymphoma Appendiceal neoplasm2. Nonneoplastic condition Peptic ulcer Strangulation: Volvulus Diverticulosis Diverticultis, colon Meckel’s diverticulum Appendicitis Stercoral perforation Inflammation Balanced penumoperitoneum3. MicellaneousConclusion ER153-ED-X Buckle Fracture of the Proximal Tibia Associated with Trampoline Use in Children All Day Room: ER Community, Learning Center Participants Saurabh Gupta, MD, Philadephia, PA (Presenter) Nothing to Disclose Victor M. Ho-Fung, MD, Philadelphia, PA (Abstract Co-Author) Nothing to Disclose Sayed Ali, MD, Aston, PA (Abstract Co-Author) Nothing to Disclose Summer L. Kaplan, MD, MS, Philadelphia, PA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Recognize subtle buckle fractures of the proximal tibia associated with trampoline and inflatable bouncer use in young children.2. Be aware that young children may not localize pain to the site of fracture and the radiologist may suggest imaging the proximal tibia in patients with trampoline related injury to the lower extremity.3. Reassure clinician of good outcomes associated with healing of these fractures. TABLE OF CONTENTS/OUTLINE 1. Demographics of trampoline use and injury2. Patient presentation3. Mechanisms: a. Hyperextension b. Bouncing with others, especially larger person4. Sample cases and mimics5. Treatment and prognosis6. Future directions and summary ER154-ED-X Stop Blaming the Gallbladder! Imaging of the Unlikely Suspects of Right Upper Quadrant Pain All Day Room: ER Community, Learning Center Participants Refky Nicola, DO, MSc, Worcester, MA (Presenter) Nothing to Disclose Adib R. Karam, MD, Worcester, MA (Abstract Co-Author) Nothing to Disclose Mariam Moshiri, MD, Seattle, WA (Abstract Co-Author) Consultant, Reed Elsevier; Author, Reed Elsevier; Puneet Bhargava, MD, Shoreline, WA (Abstract Co-Author) Editor, Reed Elsevier Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Mariano Scaglione, MD, Castel Volturno, Italy (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Discuss the advantages and disadvantages of US, CT and MRI for the evaluation of patient with acute right upper quadrant (RUQ) pain Review imaging pitfalls in a patient with RUQ pain Illustrate causes of right upper quadrant pain when the gallbladder is normal. Discuss the role of point of care ultrasound in the emergency department. TABLE OF CONTENTS/OUTLINE US mimics of acute cholecystitis will be reviewed Sonographic findings of the following non traumatic emergencies will be illustrated and reviewed: perforated duodenal ulcer, acute pancreatitis, portal vein thrombosis, tumor thrombus, ruptured hepatocellular carcinoma, acute hepatitis, giant cavernous hemangioma, hepatic steatosis, choledocholithiasis, gallbladder carcinoma, emphysematous cholecystitis, gangrenous cholecystitis, adenomyomatosis Imaging pitfalls, differential diagnosis and management options will be discussed...... . Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator Mariam Moshiri, MD - 2013 Honored Educator Mariam Moshiri, MD - 2015 Honored Educator Puneet Bhargava, MD - 2015 Honored Educator ER155-ED-X Potpourri of Emergency Radiology Abdominopelvic Cases: A Quiz for the Aces All Day Room: ER Community, Learning Center Participants Carlos Francisco M. da Silva, MD, Setubal, Portugal (Presenter) Nothing to Disclose Pedro M. Alves, MD, Lisboa, Portugal (Abstract Co-Author) Nothing to Disclose Hugo A. Rio Tinto, MD, Lisbon, Portugal (Abstract Co-Author) Nothing to Disclose Joao R. Inacio, MD, Ottawa, ON (Abstract Co-Author) Nothing to Disclose Ana N. Monica, MD, Oeiras, Portugal (Abstract Co-Author) Nothing to Disclose Jorge Brito, MD, Portimao, Portugal (Abstract Co-Author) Nothing to Disclose Maria Teresa F. Guerra, Setubal, Portugal (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The gamut of acute abdominopelvic pathology encountered in everyday practice can be varied and rare.The purpose of this exhibit is to expose radiologists to a series of challenging and rare cases in order to help improve the radiologist’s awareness and diagnostic accuracy. TABLE OF CONTENTS/OUTLINE The cases will be presented in a quiz format.Key differential diagnostic points will be highlighted in the discussion of each case.The list of cases includes: • Interparietal type of inguinal hernia • Small-bowel obstruction due to Meckel's Diverticulum • Cholecystitis presenting in a woman with agenesis of the right hepatic lobe • Situs inversus totalis • Intestinal nonrotation • Cecal volvulus • Wandering Spleen • Omental Infarct ER156-ED-X Internal Hernias: Imaging Features and Complications All Day Room: ER Community, Learning Center Participants Bella P. Desai, MD, Houston, TX (Presenter) Nothing to Disclose Latifa L. Sanhaji, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The purpose of this exhibit1. Review normal anatomy and congenital or acquired defects of the abdominal cavity2. Discuss clinical and imaging presentation of internal hernias3. Explain appropriate intervention for complications related to internal hernias TABLE OF CONTENTS/OUTLINE 1. Normal anatomy of the abdominal cavity2. Congenital and acquired defects of the abdominal cavity 3. Imaging features of internal hernias - paraduodenal, foramen of Winslow, transmesenteric, pericecal, bowel anastomoses 4. Imaging of complications of internal hernias 5. Summary ER157-ED-X It's a Soft Call: Diagnosable Soft Tissue Injury by CT in Setting of Osseous Trauma All Day Room: ER Community, Learning Center Participants Matthew L. Uriell, MD, Atlanta, GA (Presenter) Nothing to Disclose Philip K. Wong, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Yara Younan, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Ty K. Subhawong, MD, Miami, FL (Abstract Co-Author) Nothing to Disclose Monica B. Umpierrez, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Walter A. Carpenter, MD, PhD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Adam D. Singer, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS In the setting of trauma, CT is often used to assess degree of osseous injury and for surgical planning. While CT is accurate in the characterization of osseous injuries, soft tissue damage can often also be detected, however may be overlooked. Early detection of soft tissue injury by CT could serve to change management of these patients. MRI anatomy is relevant to CT anatomy and should be considered when interpreting CT soft tissue windows. TABLE OF CONTENTS/OUTLINE Introduction to Soft Tissue Injury: muscle, tendon, ligament, meniscus, nerve, vessel, skin Importance of Soft Tissue Injury for Surgical Planning, Prognosis, and Rehabilitation Case Examples Tendon/ligament/meniscus tears and avulsions Tendon entrapment Nerve injury Vascular injury Skin/soft tissue (degloving) and coverage issues ER158-ED-X Dual Energy CT Characterization of Adnexal Lesions in the Emergency Department All Day Room: ER Community, Learning Center Participants Michael T. Caton, MD, Boston, MA (Presenter) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer W. Uyeda, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Urvi P. Fulwadhva, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG TEACHING POINTS 1. Adnexal lesions are common in patients presenting to the emergency room, both as the cause of symptoms and as incidental findings on pelvic CT performed for other reasons.2. Dual Energy CT (DECT) can aid assessment of common adnexal lesions.3. DECT analysis of adnexal pathology may augment pelvic ultrasound and in some cases, obviate the need for further imaging studies. TABLE OF CONTENTS/OUTLINE 1. DECT overview: review relevant aspects of DECT technology including three material decomposition for creation of iodine maps and virtual noncontrast images, and highlight technical and workflow challenges.2. Case-based review of DECT characterization of adnexal lesions commonly encountered in the Emergency Department including ovarian torsion, tubo-ovarian abscess, and common benign and malignant adnexal masses.3. Future directions: expanding the role of DECT to increase diagnostic accuracy, reduce follow-up imaging, and improve radiology workflow. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ER161-ED-X Acute Abdomen Due to Hemorrhagic Liver Lesions All Day Room: ER Community, Learning Center Participants Elsa Camuera Gonzalez, Bilbao, Spain (Presenter) Nothing to Disclose Jenny Catalina Correa Zapata, Barakaldo, Spain (Abstract Co-Author) Nothing to Disclose Itziar Tavera Bahillo, Barakaldo, Spain (Abstract Co-Author) Nothing to Disclose Leticia Mugica, Barakaldo, Spain (Abstract Co-Author) Nothing to Disclose Ana Rosa Gil Martin, Bilbao, Spain (Abstract Co-Author) Nothing to Disclose Ricardo Ituarte Uriarte, Barakaldo, Spain (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The purpose of this exhibit is: To review the hemorrhagic liver lesions and their imaging findings. To recognize the importance of CT in the diagnosis of acute hemoperitoneum. To show different types of embolization procedures.The major teaching points are: The first diagnosis in patients with cirrhosis and hemorrhagic liver lesion will be a HCC. Young woman using long-term oral contraceptives with subcapsular hematoma may have an adenoma. TABLE OF CONTENTS/OUTLINE Spontaneous liver bleeding is an uncommon entity that usually occurs in a pathological liver. Hepatic hemorrhage, in absence of trauma or anticoagulant therapy, has been linked to anatomical lesions. The most common non-traumatic causes are hepatocellular carcinoma and adenoma. Other hemorrhagic liver lesions are metastasis, focal nodular hyperplasia or haemangiomas. This condition is potentially lethal. Patients present to emergency room with abdominal pain and hemodynamic instability.CT is the most useful technique to determine the cause and the site of bleeding. In addition, it allows for realizing a vascular map. The immediate therapy is selective arterial embolization. This procedure can produce haemostasis in hemodynamically unstable patients.Radiologists play a crucial role in the diagnosis and immediate management of hemorrhagic liver lesions. ER162-ED-X Application of Dual Energy CT for Abdominal Emergency All Day Room: ER Community, Learning Center Participants Ryosuke Abe, Tokyo, Japan (Presenter) Nothing to Disclose Takehiko Gokan, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Yuichi Nakai, tokyo, Japan (Abstract Co-Author) Nothing to Disclose Naruki Mizobuchi, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Keita Yamana, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Masanori Hirose, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To review the technology of dual energy CT including a variety of image reconstruction and postprocessing techniquesTo discuss the advantages and disadvantages of dual energy CT for the emergency abdominal radiologyTo learn how to use the advantages of dual energy CT for the emergency abdominal radiology TABLE OF CONTENTS/OUTLINE 1 Technology of dual energy CT2 Case presentation to show advantages of dual energy CT for the emergency abdominal radiology.All cases were performed with 3rd generation dual energy CT. Iodine map image can show ischemic status due to torsion of intestine, ovarian mass etc.Monoenergy low KeV image can reduced contrast dose, salvage suboptimal studies because of enhanced vascular visualization.Artifact reduction with monoenergy high KeV imageRadiation reduction with virtual noncontrast imageVirtual noncalcium image in the evaluation of bone marrow edema due to acute vertebral compression fracture3 . Case presentation to demonstrate disadvantages of dual energy CT.Suboptimal scan time of DECT etc. ER163-ED-X MDCT of Duodenal Emergencies: Utility of 2D MPRs and 3D Rendering for Challenging but Critical Diagnoses All Day Room: ER Community, Learning Center Awards Identified for RadioGraphics Participants Mikhael Polotsky, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Margaret Fynes, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Elliot K. Fishman, MD, Baltimore, MD (Abstract Co-Author) Institutional Grant support, Siemens AG; Institutional Grant support, General Electric Company; Pamela T. Johnson, MD, Baltimore, MD (Presenter) Consultant, National Decision Support Company TEACHING POINTS Emergency department patients with upper abdominal pain are often imaged with MDCT to evaluate for pancreatic, biliary, gastric or duodenal pathology. Acute, critical duodenal pathology may be overlooked if the radiologist is not knowledgable about the range of potential pathology and does not include the duodenum in their search pattern, using both axial and multiplanar MDCT interpretation. This exhibit reviews: Spectrum of acute, emergent pathology that can arise from the duodenum MDCT findings with emphasis on importance of supplementing axial with coronal and sagittal views Importance of inspecting the duodenum for accurate diagnoses TABLE OF CONTENTS/OUTLINE IntroductionMDCT technique IV contrast trend toward PO water for oral contrast in ED patients narrow reconstruction sections for high quality MPRs and 3D renderingPathology and MDCT findings severe duodenitis perforation perforated duodenal ulcer (contained and free perforation) following ERCP traumatic perforation due to stab wound duodenal hemorrage from GDA pseudoaneurysm duodenal diverticulitis duodenal hematoma duodenal obstruction Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Pamela T. Johnson, MD - 2016 Honored Educator Elliot K. Fishman, MD - 2012 Honored Educator Elliot K. Fishman, MD - 2014 Honored Educator Elliot K. Fishman, MD - 2016 Honored Educator ER164-ED-X Imaging of Acetablar Fractures: From Wreck to Rehab All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Nicholas M. Beckmann, MD, Houston, TX (Presenter) Nothing to Disclose TEACHING POINTS 1. Follow the imaging course of trauma patients with pelvic fractures from initial presentation through pelvic fracture fixation.2. Along course of following patient discuss: Controversies in pelvic fracture imaging Accurately reporting acetabular fractures using Judet-Letournel classification Important CT findings beyond fracture pattern classification Indications for non-operative vs operative managment TABLE OF CONTENTS/OUTLINE Intro/Statistics on pelvic and acetabular fx Initial presentation of patient with pelvic trauma What to look for on AP pelvis xray Are AP xrays needed if pelvis CT is done? (literature review) Acetabular fracture is identified on CT How to describe the fracture (Judet-Letournel classification) Associated findings to look for on CT Acetabular articular impaction Femoral head fx Morel-Lavallee lesion Intra-articular fragments Extravasation Pre-operative planning Is surgery even needed? (outcomes discussion) Percutaneous fixation vs open reduction-internal fixation Pre-operative imaging: Have 3D CT reformatted images obviated need for AP pelvis and Judet views? (literature review) Post-operative hardware assessment Are xray adequate or should CT be performed? (literature review) New technology: intra-operative CT ER165-ED-X Spectrum of Abdominal Aortic Emergencies: MDCT Appearance All Day Room: ER Community, Learning Center Participants Nagaramesh Chinapuvvula, MBBS, Houston, TX (Presenter) Nothing to Disclose David A. Spak, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose Suresh Cheekatla, MBBS, Houston, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To review the MDCT appearance of abdominal aortic emergencies, both traumatic and non traumatic2. To discuss the MDCT protocol that needs to be adopted for evaluating the abdominal aorta in the acute setting TABLE OF CONTENTS/OUTLINE a. MDCT signs and appearance of traumatic and non traumatic abdominal aortic emergencies which include1. Abdominal aortic aneurysm/rupture2. Aortic dissection, non traumatic3. Intramural hematoma4. Acute aortic thrombus5. Penetrating atherosclerotic ulcer6. Traumatic aortic injury7. Endoleaksb. MDCT protocol for evaluating the abdominal aorta in the emergency setting ER167-ED-X Panscan CT Techniques for Patients with High-energy Injuries All Day Room: ER Community, Learning Center Participants Keishi Ogura, RT, PhD, Sapporo, Japan (Presenter) Nothing to Disclose Kei Miyata, MD, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Syogo Misumi, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Junpei Suzuki, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Taiki Chono, RT, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Masaki Abukawa, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Yoshiya Oohashi, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Kenta Yoshikawa, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Syunpei Katoh, Sapporo, Japan (Abstract Co-Author) Nothing to Disclose Masamitsu Hatakenaka, MD, PhD, Sapporo, Japan (Abstract Co-Author) Research Grant, Toshiba Corporation; TEACHING POINTS This exhibit will:Demonstrate the necessity of panscan computed tomography (CT) for patients with high-energy injuries. Demonstrate optimized scan protocols for high diagnostic performance using reduced radiation dose.Present the impact of using panscan CT with increased sensitivityDescribe the methods for using clinical data to create three-dimensional (3D) images in patients with high-energy injuries. TABLE OF CONTENTS/OUTLINE This exhibit is designed to highlight important issues and considerations during imaging of patients with high-energy injuries.Necessities for panscan CT:High accuracy for a wide range of injuriesHigh rates of detectionRapid application.Optimal scan conditions:Demonstrate the optimal scanning protocols to maintain high diagnostic performance with minimized radiation dose.Determine the optimal timing for panscan CT and administration of contrast agents.Present methods for reducing image noise and artifacts using iterative reconstruction.Benefits of using 3D images for high diagnostic accuracy in high-energy injury cases:Immediate determination of the presence and extent of active bleeding.Provision of a map of injured vessels to determine the appropriate therapeutic strategy.Improved understanding of the complex fractures. ER168-ED-X Reporting More Than Just Emergent Findings - Role of Detailed Abdominal and Pelvic Imaging in Oncologic Emergencies All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Alexa O. Levey, MD, Atlanta, GA (Presenter) Nothing to Disclose Peter A. Harri, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Pardeep K. Mittal, MD, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Lauren F. Alexander, MD, Atlanta, GA (Abstract Co-Author) Spouse, Stockholder, Abbott Laboratories; Spouse, Stockholder, AbbVie Inc; Spouse, Stockholder, General Electric Company Courtney A. Coursey Moreno, MD, Suwanee, GA (Abstract Co-Author) Nothing to Disclose Frank H. Miller, MD, Chicago, IL (Abstract Co-Author) Research Grant, Siemens AG Bobby T. Kalb, MD, Tucson, AZ (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Review the types of diagnoses that present emergently to radiologists on cross sectional imaging secondary to malignancies. 2. Describe the important details and subtle findings of the malignancy that go beyond reporting the presenting diagnosis and can speed up oncologic treatment. 3. Discuss the impact of accurate initial diagnosis of a malignancy, characterization, and early description, on clinical management and reducing repeat imaging. TABLE OF CONTENTS/OUTLINE 1. Review common primary and secondary abdominal and pelvic malignancies that cause morbidity requiring emergent imaging. 2. Review important findings of the underlying malignancies that should be discussed to expedite oncologic treatment. a. The hepatic system: masses causing intrapertioneal hemorrhage. b. The pancreaticobiliary system: cholangiocarinoma and pancreatic cancer causing jaundice and right upper quadrant pain. c. The gastrointestinal tract: colorectal adenocaricoma and ovarian cancer causing bowel obstruction. d. The genitourinary tract: renal cell carcinoma and urothelial cell carcinoma causing hematuria and cervical cancer causing urinary obstruction. 3. Discuss the impact of accurate pre-surgical evaluation and staging on management and treatment options. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Courtney A. Coursey Moreno, MD - 2016 Honored Educator Pardeep K. Mittal, MD - 2016 Honored Educator Frank H. Miller, MD - 2012 Honored Educator Frank H. Miller, MD - 2014 Honored Educator ER169-ED-X Posterior Reversible Encephalopathy Syndrome: What's in a Name? Catch Subtle Signals! All Day Room: ER Community, Learning Center Participants Madhav Hegde, MD, Bangalore, India (Presenter) Nothing to Disclose Anuradha Rao, Bangalore, India (Abstract Co-Author) Nothing to Disclose Sharath Kumar G.G, MBBS,MD, Bangalore, India (Abstract Co-Author) Nothing to Disclose Balakrishna P. Shetty, MBBS, Bangalore, India (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1.To understand that PRES is not a single diagnostic entity,but is an inclusive term for “similar” imaging appearance in various clinical scenarios in emergency room2.To acquiant radiologists the typical and atypical imaging features in PRES3.To highlight the importance of identifying this entity distinctly in its subtle forms from other imitators in confusing clinical scenarios,thus preventing delay in patient care4.To stress on the 'non posterior' and 'irreversible' components masked in its name TABLE OF CONTENTS/OUTLINE 1.Common clinical associations with typical clinical presentations.2. Pathogenesis.3.Usual imaging features,highlighting on reversibility.4.Unusual,atypical imaging features,various patterns on imaging including holohemisphereic, superior frontal sulcus pattern,dominant parieto-occipital pattern,assymetric/partial expressions.5.Imaging appearance on CT,MR,MRA and DWI.6.Complications of PRES-hemorrhage and infarction.7.Imaging Mimics : PML, infectious encephalitis, acute disseminated encephalomyelitis, cerebral venous sinus thrombosis,ischemic stroke; In isolated brain stem variety-pontine infarct,osmotic demyelination,brainstem encephalitis as mimics.8.Clinical mimics of PRES-seizures of various causes, migraine.9.Mimics in hemorrhagic variety-ADEM. ER170-ED-X A Race Against the Clock: Imaging of Life Threatening Cardiovascular Emergencies All Day Room: ER Community, Learning Center Participants Malay Bhatt, MD, Royal Oak, MI (Presenter) Nothing to Disclose Nick Sousaris, MD, Rootstown, OH (Abstract Co-Author) Nothing to Disclose Sayf A. Al-Katib, MD, Royal Oak, MI (Abstract Co-Author) Nothing to Disclose Syed Zafar H. Jafri, MD, Royal Oak, MI (Abstract Co-Author) Nothing to Disclose Kostaki G. Bis, MD, Bloomfield Hills, MI (Abstract Co-Author) Nothing to Disclose Hanh V. Nghiem, MD, Royal Oak, MI (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Advanced imaging studies are continuing to become more quickly accessible. This trend has increased the demand for timely and accurate interpretations by the radiologist. The purpose of this exhibit is: To display a myriad of cases to alert the radiologist to a variety of common and uncommon life threatening cardiovascular emergencies. To review the pertinent imaging findings of each diagnosis and highlight the key elements to consider in one’s diagnostic search pattern. TABLE OF CONTENTS/OUTLINE A multitude of cases will be displayed with subsequent case discussions that provide pertinent imaging findings and review key diagnostic and differential considerations. Cardiovascular Emergencies Cardiac Cardiac tamponade Ventricular pseudoaneurysm Coronary artery anomalies LIMA graft pseudoaneurysm Thoracic Massive pulmonary embolism Aortic dissection Traumatic aortic pseudoaneurysm Aorto-esophageal fistula Abdominal Aortic aneurysm rupture Aortoenteric fistula Mycotic aneurysm Portal vein thrombosis with bowel ischemia SMA thrombus Mesenteric vascular traumatic injury Pelvic Pelvic hemorrhage due to various traumatic vascular injuries ER171-ED-X Wooden Foreign Bodies in the Gastro-intestinal Tract: A Challenge for the Radiologist All Day Room: ER Community, Learning Center Participants Michele Porcu, MD, Cagliari, Italy (Presenter) Nothing to Disclose Giovanni M. Argiolas, MD, Monserrato, Italy (Abstract Co-Author) Nothing to Disclose Federica Schirru, MD, Nurri, Italy (Abstract Co-Author) Nothing to Disclose Paolo Siotto, MD, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose Jasjit S. Suri, Pocatello, ID (Abstract Co-Author) Nothing to Disclose Luca Saba, MD, Cagliari, Italy (Abstract Co-Author) Nothing to Disclose TEACHING POINTS To review the main direct and undirect findings of the presence of a ingested wooden foreign body along the gastro-intestinal tract To expose the complication that can origin from the presence of wooden foreign bodies along the gastro-intestinal tract. TABLE OF CONTENTS/OUTLINE The ingestion of foreign bodies, accidental or not, is a frequent cause of admission to the emergency department, especially in the paediatric population. In case of the presence of a foreign body in the gastro-intestinal tract the radiologist has to work with the other members of the clinical team in order to promptly recognise the causes of disease, to detect the foreign body and to avoid or limit complications (in particular perforations, occlusions or sub-occlusions and haemorrhages). The wooden objects (in particular those with sharp ends, such as toothpicks), represent a challenge for the Radiologist because of its composition; in fact it is not as much radiopaque as other objects, and its detection with conventional radiology or computed tomography can be very difficult. In this job we expose a case report of a man who came in our emergency department with a two days story of acute abdomen following the accidentally ingestion of a toothpick. ER173-ED-X Thinking Outside the Myocardium: Imaging Review of Non-cardiac, Non-traumatic Causes of Acute Chest Pain All Day Room: ER Community, Learning Center Awards Certificate of Merit Participants Junichi Tsuchiya, MD, Tokyo, Japan (Presenter) Nothing to Disclose Yasuyuki Kurihara, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Ryo Miyazawa, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Masaki Matsusako, MD, PhD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Jay Starkey, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose TEACHING POINTS (1) To teach the differential diagnoses of acute chest pain in the emergency room in cases of non-cardiac, non-traumatic causes.(2) To teach relevant anatomy and pathophysiology. TABLE OF CONTENTS/OUTLINE I. Review of anatomy on chest radiograph, CT, and MRI, including: great vessels, mediastinum, pleura, pericardium, esophagus, and spinal cord.II. The cases will be presented in a quiz format. Review of pathophysiology and images as unknowns in cases where the patient presents with acute chest pain and without history of trauma to the Emergency Dept. Cases include:-Pulmonary Pulmonary embolism Idiopathic pneumomediastinum Pneumothorax-Aorta Aortic dissection Aortic rupture-Pericardium Pericarditis-Esophagus Idiopathic esophageal rupture; Boerhaave syndrome Esophageal Anisakis-Spine Spinal epidural hematoma-Mediastinum Benign matured teratoma Malignant lymphoma ER174-ED-X Traumatic Retroperitoneal Hemorrhage: MDCT Evaluation and Importance of Zonal Anatomy for Management All Day Room: ER Community, Learning Center Participants Nagaramesh Chinapuvvula, MBBS, Houston, TX (Presenter) Nothing to Disclose Suresh Cheekatla, MBBS, Houston, TX (Abstract Co-Author) Nothing to Disclose O. C. West, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. To discuss the zonal anatomy of the retroperitoneum ( Zones I,II,III) on MDCT which is critically important to the surgeon for management.2. To familiarize the viewer the appearance of retroperitonel hemorrhage on MDCT and elaborate the common sources of hemorrhage in the trauma setting.3. To emphasize the importance of including the location of retroperitonel hemorrhage ( Zone I,II,III) in the CT report, especially when no obvious contributing source can be identified in the trauma patient .5. To give an insight into how retroperitoneal hemorrhage is managed. TABLE OF CONTENTS/OUTLINE 1. Zone 1 ( central ) retroperitoneal hemorrhage: MDCT appearance of major vascular injuries including abdominal aorta and IVC injuries with or without active vascular extravasation; pancreatico duodenal injuries which are major contributors to central retroperitoneal hemorrhage2. Zone 2 ( lateral) retroperitoneal hemorrhage: MDCT appearance of renal, adrenal and proximal ureteral injuries contributing to lateral retroperitoneal hemorrhage3. Zone 3 ( pelvic) retroperitoneal hemorrhage: MDCT appearance of iliac vascular injuires, pelvic fractures contributing to pelvic retroperitoneal hemorrhage4. Management of retroperitoneal hemorrhage ER175-ED-X Multimodality Imaging of Non-Aortic Cardiothoracic Trauma All Day Room: ER Community, Learning Center Participants Sachin S. Saboo, MD, FRCR, Dallas, TX (Presenter) Nothing to Disclose Kirk G. Jordan, MD, Dallas, TX (Abstract Co-Author) Nothing to Disclose Kiran Batra, MD, Coppell, TX (Abstract Co-Author) Nothing to Disclose Prabhakar Rajiah, MD, FRCR, Dallas, TX (Abstract Co-Author) Institutional Research Grant, Koninklijke Philips NV; Speaker, Koninklijke Philips NV Asha Kandathil, MD, Dallas, TX (Abstract Co-Author) Nothing to Disclose Suhny Abbara, MD, Dallas, TX (Abstract Co-Author) Author, Reed Elsevier; Editor, Reed Elsevier; Institutional research agreement, Koninklijke Philips NV; Institutional research agreement, Siemens AG Jacqueline T. Caire, MD, Dallas, TX (Abstract Co-Author) Nothing to Disclose Devri L. Weakley, MD, Dallas, TX (Abstract Co-Author) Nothing to Disclose Ashish R. Khandelwal, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Prashant Nagpal, MBBS, Iowa, IA (Abstract Co-Author) Nothing to Disclose Michael J. Landay, MD, Dallas, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Describe plain radiographic and CT features of various manifestations of non-aortic injury in the chest associated with blunt, penetrating, and barotrauma Review classical radiographic signs associated with thoracic injury Radiologist and clinicians should be able to recognize imaging findings of trauma in acute and chronic settings involving airway, parenchyma, mediastinum, diaphragm, and chest wall that may require further imaging and/or surgical or interventional management. TABLE OF CONTENTS/OUTLINE Trauma associated visits to the Emergency Room: High-speed motor vehicles Blunt trauma related to fall Penetrating trauma BarotraumaNon-aortic traumatic chest injury: Mediastinal: Pericardial, Myocardial, Esophageal Vascular: Systemic and Pulmonary arterial Lungs and Airways:Hemorrhage/Contusions, Lacerations, Bronchopleural Fistula,Pulmonary Interstitial Emphysema Diaphragmatic:Rupture, Paralysis Chest wall:Flail Chest, Lung Hernia, FracturesRadiographic Signs Deep sulcus Double Diaphragm Mediastinal shift Contiguous Diaphragm Thymic Sail Ring around the Artery Fallen Lung Dependent Viscera Collar Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Suhny Abbara, MD - 2014 Honored Educator Prabhakar Rajiah, MD, FRCR - 2014 Honored Educator ER176-ED-X Gynecological Emergencies: Pictorial Review All Day Room: ER Community, Learning Center FDA Discussions may include off-label uses. Awards Certificate of Merit Participants Catarina A. Silva, MD, Senhora da Hora, Portugal (Presenter) Nothing to Disclose Ines Sarmento, Matosinhos, Portugal (Abstract Co-Author) Nothing to Disclose Joao C. Pinto, Matosinhos, Portugal (Abstract Co-Author) Nothing to Disclose TEACHING POINTS The purpose of this exhibit is: Provide concise imaging review of gynecological emergencies, focusing on the cross sectional techniques (MDCT and MRI) Learn to recognize the differential diagnosis Know how to optimize imaging protocols, based on personal experience, in order to assure the correct diagnosis. TABLE OF CONTENTS/OUTLINE Anatomy of the female internal genitalia Gyn emergencies: how to optimize the protocols MDCT MRI Common Gyn emergencies: Cross sectional Imaging findings with pathological correlation Ovarian/adnexal torsion Ruptured hemorrhagic cyst Tubo-ovarian abscess/PID Ectopic pregnancy Uncommon Gyn emergencies: Cross sectional Imaging Findings with pathological correlation Infected uterine tumor Uterine rupture Bleeding uterine tumor /AVN Acute teratoma complications Diferential diagnosis Acute appendicitis Diverticular perforation Diverticulitis Ureterolithiasis Cystitis Spontaneous iliopsoas haematoma GI invasive/perforated tumor Summary ER177-ED-X The Fart and The Furious: A Pictorial Review of the Mild and the Severe Intestinal Disorders an ER Radiologist Should Master All Day Room: ER Community, Learning Center Participants Natalia Romero, MD, Hospitalet De Llobregat, Spain (Presenter) Nothing to Disclose Lara Farras Roca, MD, Barcelona, Spain (Abstract Co-Author) Nothing to Disclose Ivan Carrion, MD, Hospital de Llobregat, Spain (Abstract Co-Author) Nothing to Disclose Camilo Pineda Ibarra, MD, Barcelona, Spain (Abstract Co-Author) Nothing to Disclose Teresa Martinez Fernandez, Lhospitalet De Llobregat, Spain (Abstract Co-Author) Nothing to Disclose Eugenia De Lama Salvador, MD, Barcelona, Spain (Abstract Co-Author) Nothing to Disclose TEACHING POINTS - To describe the main clinical presentation of acute intestinal conditions most frequently seen in the ER department.- To review the typical radiological findings of each entity and potential imaging pitfalls.- To identify benign conditions that present with similar symptoms as potentially severe conditions.- To provide useful tools and appropiated CT protocols for each scenario. TABLE OF CONTENTS/OUTLINE There are several scenarios in the ER with potentially fast and fatal course (rigid wooden abdomen, lower tract occlusion, hypovolemic shock…) which push us to establish an immediate diagnosis. Most of the time, however, we will find benign disease as the cause (enteritis, constipation, Ogilvie's, ), which will be properly studied at a later time.However, there are some other entities we should take into account and should be included as a possible differential diagnosis as we face an acute abdomen, such as:Inflammatory conditions: diverticulitis, intestinal inflamatory disease, pseudomembranous colitis- Lower tract occlusion: secondary to tumor cause, bezoar or foreign body.- Acute rectal bleeding; intestinal or extrinsecal (aortic fistulae)- Colonic volvulus, internal hernias.- Ischaemic conditions with associated pneumatosis.We aim to help provide a fast and accurate diagnosis in a timesensitive environment ER179-ED-X Role of Dual Energy CT in Pancreatic Disease: A Pictorial Review All Day Room: ER Community, Learning Center Participants Elizabeth George, MD, Boston, MA (Presenter) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer W. Uyeda, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Urvi P. Fulwadhva, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG TEACHING POINTS 1. Dual energy CT acquisition enables the creation of iodine maps, virtual noncontrast, and virtual monoenergetic images from a single post-contrast acquisition. 2. Pancreatic pathologies offer a particular challenge in abdominal CT due to the subtlety of critical imaging findings. The use of dual energy CT can improve characterization of pancreatic diseases, including adenocarcinoma, cystic lesions, and pancreatitis. 3. Application of dual energy CT post-processing can potentially aid early and accurate diagnosis of pancreatic pathologies, while avoiding the need for additional imaging phases or modalities. TABLE OF CONTENTS/OUTLINE 1. Review of the relevant physics and principles of dual energy CT. 2. Current applications of dual energy CT for various pancreatic pathologies.A. Case based review of the use of iodine maps, virtual non-contrast, and virtual monoenergetic images in the identification and characterization of focal pancreatic lesions, such as adenocarcinoma, cystic lesions, and other neoplasms such as neuroendocrine tumors. Correlation with other imaging modalities and potential reduction in follow-up imaging will be discussed. B. Review of potential applications of dual energy technology in pancreatitis, including early detection of necrosis and vascular complications, and characterization of pancreatic/peripancreatic collections. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ER180-ED-X Abdominal Emergencies in Patients with Undiagnosed Tumor: A Diagnostic Dilemma All Day Room: ER Community, Learning Center Participants Sandra M. Ramirez, MD, Medellin, Colombia (Presenter) Nothing to Disclose Vanessa Garcia, Medellin, Colombia (Abstract Co-Author) Nothing to Disclose Claudia P. Huertas, MD, Medellin, Colombia (Abstract Co-Author) Nothing to Disclose Viviana Marcela Palacio Castano, Medellin, Colombia (Abstract Co-Author) Nothing to Disclose Tatiana Suarez, MD, Medellin, Colombia (Abstract Co-Author) Nothing to Disclose TEACHING POINTS Acute complications caused by abdominal malignancies in patients with undiagnosed tumor are potentially fatal conditions.Complications represent a diagnostic dilema in the ER and some of them include hemorrhagic cholecystitis in gallbladder carcinoma, hemoperitoneum secondary to rupture of HCC, bleeding from adrenocortical carcinoma, urinoma due to ureter obstruction from nodal lymphoma, bladder outlet obstruction due to prostatic sarcoma, bowel obstruction due to invaginated lymphoma in the ileocecal valve, abdominal abscess due to rupture of cholangiocarcinoma, acute abdominal pain due to renal artery thrombosis by renal cell carcinoma, acute pancreatitis due to pancreatic adenocarcinoma, acute abdominal pain due to appendiceal neuroendocrine, among others. The purpose of this exhibit is: - To identify the CT imaging appearances of acute and potentially fatal complications caused by abdominal malignancies in patients with undiagnosed tumor as differential diagnosis from classic acute abdomen etiologies.- To discuss clinical scenarios that may lead to the development of abdominal emergencies secondary to abdominal neoplasms. TABLE OF CONTENTS/OUTLINE - Tumors presenting with abdominal bleeding- Obstructive conditions secondary to neoplasms- Tumors presenting as perforated hollow viscus- Tumors presenting with acute abdominal pain ED004-SU Emergency Radiology Sunday Case of the Day Sunday, Nov. 27 7:00AM - 11:59PM Room: Case of Day, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose David Dreizin, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Manickam Kumaravel, MD, FRCR, Houston, TX (Abstract Co-Author) Nothing to Disclose Constantine A. Raptis, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose David D. Bates, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thomas Battey, Timonium, MD (Abstract Co-Author) Nothing to Disclose Nicholas M. Beckmann, MD, Houston, TX (Program Committee Staff) Nothing to Disclose TEACHING POINTS 1) Recognize key imaging findings on multimodality imaging of emergency/trauma patients. 2) Develop differential diagnosis based on the clinical information and imaging findings. 3) Recommend appropriate management including image-guided interventions. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator SSA06 Emergency Radiology (Utilization and Practice Management) Sunday, Nov. 27 10:45AM - 12:15PM Room: N226 CT ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Karen S. Lee, MD, Boston, MA (Moderator) Nothing to Disclose Michael N. Patlas, MD, FRCPC, Hamilton, ON (Moderator) Nothing to Disclose Sub-Events SSA06-01 Accuracy of Outside Radiologists' Reports of Computed Tomography Exams of Emergently Transferred Patients Sunday, Nov. 27 10:45AM - 10:55AM Room: N226 Participants Jeffrey D. Robinson, MD, MBA, Seattle, WA (Presenter) Consultant, HealthHelp, LLC; President, Cleareview, Inc; Ken F. Linnau, MD, MS, Seattle, WA (Abstract Co-Author) Royalties, Cambridge University Press; Speaker, Siemens AG Daniel S. Hippe, MS, Seattle, WA (Abstract Co-Author) Research Grant, Koninklijke Philips NV; Research Grant, General Electric Company Kellie L. Sheehan, Seattle, WA (Abstract Co-Author) Nothing to Disclose Joel A. Gross, MD, MS, Seattle, WA (Abstract Co-Author) Nothing to Disclose PURPOSE Determine the concordance rate of CT interpretations of emergently transferred patients to a Level 1 trauma center. METHOD AND MATERIALS The IRB determined this retrospective study to be exempt after reviewing the study protocol. Outside CT scans of all adult patients transferred to the Emergency Department of a Level 1 trauma center from May 9, 2015 to June 9, 2015 were retrospectively reviewed. Patients were categorized as trauma or non-trauma transfers. The original imaging report was compared to the reviewer’s findings, and categorized as concordant or discordant. Discordant findings were rated as minor, moderate or major. Major discordances were defined as having the potential to impact clinical management. Rates of each type of discordance and 95% confidence intervals (CIs) were calculated per transfer and per exam. RESULTS 628 CT scans from 327 transfers were reviewed. There were 213 (65%) trauma transfers and 114 (35%) non-trauma transfers, corresponding to 490 trauma-related exams and 138 non-trauma exams. Of the 327 total transfers, there were 119 (36%, 95% CI: 31-42%) with any discordance and 56 (17%, 95% CI: 13-22%) with at least one major discordance. These major discordances were identified in 49 (23%, 95% CI: 18-29%) of the 213 trauma transfers and 7 (6.1%, 95% CI: 2.7-13%) of the non-trauma transfers (p<0.001 for the difference). On a per exam basis, 59 of 628 (9.4%) total exams had a major discordance. Among the trauma-related exams and non-trauma exams there were 51 (10%) and 8 (5.8%) major discordances, respectively. The rates of major, moderate and minor discordances are further summarized in the Figure. CONCLUSION We identified major interpretive discrepancies in the CT scans of 17% of patients emergently transferred to a Level 1 trauma center. Trauma transfer patients were significantly more likely to have a major discordance than non-trauma transfer patients. CLINICAL RELEVANCE/APPLICATION Routine over-reading of pre-transfer CT scans may be justified due to the substantial likelihood of a major discordance in interpretation that may impact the clinical management of patients. SSA06-02 Repeated CT Scans in Trauma Transfers: An Analysis of Indications, Radiation Dose Exposure, and Costs Sunday, Nov. 27 10:55AM - 11:05AM Room: N226 Participants Ricarda M. Hinzpeter, MD, Zurich, Switzerland (Presenter) Nothing to Disclose Kai Sprengel, MD, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Hatem Alkadhi, MD, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose PURPOSE To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. METHOD AND MATERIALS This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using. RESULTS Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n=45, 52.9%) and major body trauma (n=23; 27.1%) not manageable in the referring hospital, repatriation from a foreign country (n=14; 16.5%), and no ICU-capacity (n=3; 3.5%). Of these 85 patients, 74 (87.1%) had repeated CT in our center because of inadequate CT data transfer (n=29; 39.2%), repetition of head CT with completion to WBCT (n=24; 32.4%), and follow-up of known injury (n=21; 28.4%). None occurred because of poor image quality. Cumulative DLP and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81’304mGy*cm) and 40’192$, respectively.The mean time from trauma to admission to our center was significantly shorter in patients without repeated CT (median 1.5 ± 3 hours) as compared to those with repeated CT (median 3.0 ± 19 hours, p<0.001). CONCLUSION A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system. CLINICAL RELEVANCE/APPLICATION Repetition of CT in trauma patients occurs relatively often and mainly is caused by inadequate image data transfer. SSA06-03 Prospective Implementation of a Triage System to Prioritize Review and Finalization of Preliminary Reports with Emergent Findings Sunday, Nov. 27 11:05AM - 11:15AM Room: N226 Awards Student Travel Stipend Award Participants Hriday Shah, MD, San Francisco, CA (Presenter) Nothing to Disclose Stanley Lee, San Francisco, CA (Abstract Co-Author) Nothing to Disclose Joseph Mesterhazy, BS, San Francisco, CA (Abstract Co-Author) Nothing to Disclose Eric C. Ehman, MD, Pacifica, CA (Abstract Co-Author) Nothing to Disclose Javier Villanueva-Meyer, MD, San Francisco, CA (Abstract Co-Author) Nothing to Disclose Soonmee Cha, MD, San Francisco, CA (Abstract Co-Author) Nothing to Disclose Jason F. Talbott, MD, PhD, San Francisco, CA (Abstract Co-Author) Data Safety Monitoring Board, StemCells, Inc PURPOSE In an academic center, expedient finalization of radiology reports with emergent findings is challenging but clinically critical. We prospectively investigated the efficacy of a PACS-based system that allows trainees taking independent call to rapidly prioritize attending review and finalization of preliminary reports with critical findings. METHOD AND MATERIALS On-call trainees triaged studies using a PACS-based system based on their impression of study acuity. "Prelim 1" was defined as studies with emergent radiologic findings, "Prelim 2" as studies with subacute or no concerning findings, and "Prelim 3" as outpatient studies with non-urgent findings. Triage status and final dictation times were queried for consecutive CT preliminary reports from weeknights between July 1, 2015 and March 23, 2016. Discrepancies between preliminary and final reports were scored as major or minor by a board-certified radiologist. Dictation times between triage statuses were compared using ANOVA testing. The proportion of reports finalized before 12pm and discrepancy rates were compared by triage status using Fisher's exact test. RESULTS A total of 6597 studies were initially interpreted by trainees on call over 9 months. Of these, 2671 (40.4%) were triaged as Prelim 1, 3427 (51.9%) as Prelim 2, 199 (3.0%) as Prelim 3, and 300 (4.5%) were not triaged. Prelim 1 studies were finalized earlier than the remainder of the studies (p<0.01). The average final dictation time was 9:50am for Prelim 1 studies, 10:23am for Prelim 2 studies, and 10:38am for Prelim 3 studies. The percentage of studies dictated before 12 pm was also significantly different by triage status: 93% for Prelim 1, 87% for Prelim 2 and 83% for Prelim 3 (p<0.01). Major discrepancies occurred in 1% of Prelim 1 studies compared to 0.5% of Prelim 2 studies (p=0.24). CONCLUSION We successfully implemented a triage system at a large academic center to expedite attending review and finalization of preliminary reports ruling acute findings. Our data shows that this triage system is effective in prioritizing finalization of high-priority studies with acute clinical implications. CLINICAL RELEVANCE/APPLICATION At teaching institutions, finalization of preliminary reports can be triaged based on acuity of findings to improve patient care. Our triage method is easy to implement and generalizable to other academic institutions. SSA06-04 Impact of Insurance Status on Obtaining Recommended Imaging Follow-Up of Incidental Pulmonary Nodules Identified in the Emergency Department Sunday, Nov. 27 11:15AM - 11:25AM Room: N226 Participants Michael S. Kelleher Jr, MD, New Haven, CT (Abstract Co-Author) Nothing to Disclose Lauren Sapienza, New Haven, CT (Abstract Co-Author) Nothing to Disclose Howard P. Forman, MD, New Haven, CT (Presenter) Nothing to Disclose PURPOSE Communication of imaging follow-up recommendations is essential for optimal patient care. Despite effective communication, many patients do not receive recommended follow-up. We sought to determine if patient insurance status impacts the percentage of patients who successfully complete recommended imaging follow-up in the emergency department setting METHOD AND MATERIALS Our institution’s IRB deemed this study a QI project. During the month of February 2016, a retrospective chart review identified patients who presented to our ED during the year 2014 who were found to have 4-8mm incidental pulmonary nodules. Patients with a history of pulmonary nodules or malignancy were excluded, as were those who died during the recommended follow-up period. We then determined if follow-up imaging was performed. Patient demographics, including insurance status were recorded. We then contacted the primary care providers for patients who did not undergo imaging follow-up in our healthcare system to determine if the provider was aware of follow-up and if it had been performed at an outside facility. Descriptive statistics were then calculated and p values were determined using a Fisher’s exact test. RESULTS 87 patients met study criteria. 27 patients were excluded with the most common reason being death during the follow-up period (11/27). Average patient age was 62.6 years (range 36-91 years). 21% (21/87) of patients received follow-up imaging. A significantly higher percentage of patients with private insurance received follow-up compared to those on Medicare (p=0.02) as well as compared to those on Medicaid or uninsured (p=0.02). Of patients who did not receive imaging follow-up within our health care system, 11% had imaging follow-up performed at an outside facility, 11% did not show up for follow-up imaging, and in 78% of patients the primary care provider was not aware of the need for follow-up. CONCLUSION A minority of our emergency department patients obtain recommended lung nodule follow-up. Of those who do, the majority have private insurance. These findings suggest that reporting and communicating is not enough and that additional strategies must be implemented in order to “close the loop.” CLINICAL RELEVANCE/APPLICATION We have found that despite appropriately communicating critical results, the "loop" is infrequently closed for emergency department patients found to have incidental pulmonary nodules. SSA06-05 Assessing the Gap in First or Senior Female Authorship in the Journal Emergency Radiology: Trends Over a 20-year Period Sunday, Nov. 27 11:25AM - 11:35AM Room: N226 Awards Student Travel Stipend Award Participants Kristopher McKenzie, MD, Pontiac, MI (Presenter) Nothing to Disclose Milita Ramonas, MD, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose PURPOSE To examine trends in female first and senior (listed last) authors in the journal Emergency Radiology, from January 1994 to December 2014. METHOD AND MATERIALS Two researchers retrospectively reviewed a total of 1617 articles in the journal Emergency Radiology. Original articles, case reports, review articles, and pictorial essays were included. However, articles including letters, acknowledgements, communications, commentaries, editorials, status reports, book reviews, technical notes, annual meeting reports, proceedings, point counterpoints, clinical quizzes, challenge cases, and abstract reviews were all excluded. Special editions or supplementary issues were also excluded from analysis. Author’s gender was categorized as male or female using the knowledge of basic names that are commonly associated with gender (such as Anna for female and John for male). For less common names, a Google search was performed with the author’s names. The first 30 search listings were examined to determine the gender of the author. If the gender was still uncertain, the author was excluded. Comparative statistical tests were performed using a commercially available statistical package (SPSS). RESULTS Out of a total of 1617 articles reviewed, there were 1420 articles fulfilling the inclusion criteria. There were a total of 1420 first authors and 1295 senior authors.125 were solo authors. We were able to confidently determine the gender of 96% of first authors (1368 of 1420), and 96% of last authors (1246 of 1295). Overall, female authors constituted 20% of first authors (290 of 1420), and 14% of last authors (180 of 1295). The increase in female first authors throughout the last 20 years was non-significant, from 17.5% in 1994 to 20.9% in 2014 (P = 0.514). However, there was significant increase in female last authors, from 12.9% in 1994, to 21.3% in 2014 (P= 0.026). CONCLUSION Over last 20 years, there has been statistically significant upward linear trend of female senior authorship in the journal Emergency Radiology, and a non-statistically significant increase in female first authorship. CLINICAL RELEVANCE/APPLICATION Despite an increase in female authors in the Emergency Radiology journal over last two decades, the authorship remains low and female participation should be encouraged. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator SSA06-06 Inadequate Clinical Information in Emergency Radiology Consultations-Does it Really Affect the Error Rate or is it Merely a Bugbear? Sunday, Nov. 27 11:35AM - 11:45AM Room: N226 Participants Anjali Agrawal, MD, Delhi, India (Presenter) Nothing to Disclose Arjun Kalyanpur, MD, Bangalore, India (Abstract Co-Author) CEO, Teleradiology Solutions Pvt Ltd PURPOSE The frustration of receiving inadequate clinical information during a referral is well known to any practicing radiologist. We sought to determine if there was any correlation between the quality of clinical information and the types of errors in our emergency teleradiology practice. METHOD AND MATERIALS We maintain a record of cases sent for quality assurance (QA) review by our client radiology practices. These comprise less than 1% of all cases and are scored as per ACR RADPEER guidelines, ranging from 1 (no error) to 4 (obvious miss), further denoted as “a” (clinically insignificant) or “b” (clinically significant). In 831 cases flagged for QA review, we additionally scored the quality of clinical information – category 1 (inadequate), 2 (adequate), 3 (detailed), for the study type ordered, and without knowledge of the missed findings or the QA grade. Similarly, we also scored 304 cases where no QA was flagged. Chi-square tests and regression models were used to determine the associations between quality of clinical information and radiologic error. RESULTS Surprisingly, detailed histories (Category 3) were less frequent in the cases without QA than those with QA or error (p < 0.01). There was no significant influence of clinical information score upon QA category. More history did not reduce the rates of obvious errors or any errors. Stronger effects were seen for the type of study, with MR studies being significantly associated with increased rates of clinically significant (ACR “b”) errors (p=0.008). The level of clinical information was not associated with any reduction in the proportion of significant error (ACR2b, 3b, 4b), when compared to no error. CONCLUSION It is likely that experienced radiologists do not require much clinical information to reach an accurate radiological diagnosis in the emergent setting with a relatively well defined mix of cases. Whether this is also true for radiologists-in-training or those in the early years of practice needs to be tested. CLINICAL RELEVANCE/APPLICATION Perceived inadequate clinical information by radiologists does not translate to increased rates of radiologic error, at least in an emergency radiology setting with experienced radiologists. SSA06-07 Emergency Radiology Resident Interpretation in an Era of 24-7 Radiology Attending Coverage and Supervision Sunday, Nov. 27 11:45AM - 11:55AM Room: N226 Awards Student Travel Stipend Award Participants Siavash Behbahani, MD, Mineola, NY (Presenter) Nothing to Disclose A. Orlando Ortiz, MD, MBA, Mineola, NY (Abstract Co-Author) Nothing to Disclose PURPOSE To assess the impact of 24-7 in-house radiology attending coverage on radiology resident performance METHOD AND MATERIALS We retrospectively reviewed radiology resident reports on emergent diagnostic radiology procedures over an 11 month period. The emergent studies included plain radiographs and cross sectional examinations (US, CT and MRI). All reports where assessed for accuracy in terms of missed findings as compared to the final attending reading. Missed findings were identified using emergency room call back forms. The missed findings were categorized as minor or major depending on whether or not the finding impacted on subsequent patient management. A radiology attending and resident reviewed each missed finding in order to determine, by consensus, the significance of the missed finding. Resident performance was also stratified by year of training. These data were compared to a metanalysis of historical resident performance as gleamed from the radiology literature. RESULTS During 11 months, a total number of 29,636 studies were preliminary interpreted by 17 radiology residents on call under 24/7 supervision of an in-house radiology attending. The resident-faculty discrepancy rate for radiographs is 0.8% vs. 1.4% (based on literature). For cross-sectional studies the rates were: CT 0.5% vs. 2.4%, US 0.1% vs. 0.6%, MR 1.1% vs. 3.7%, based on literature, respectively. With respect to plain radiographs the most common area for discrepant findings was chest radiography. The rate of minor and major discrepancy substantially decreased by increasing resident year of training CONCLUSION Radiology resident on-call performance, with respect to diagnostic radiology interpretations, improves with the presence of 24-7 inhouse radiology attending coverage. In-house radiology attending coverage and supervision ultimately improves patient care, emergency room management/discharge time, and appropriateness of management. CLINICAL RELEVANCE/APPLICATION In a new era of the provision of real-time radiology services, a concern has arisen regarding the educational experience and performance of radiology residents who take call in programs where an in-house radiology attending is available. Our results show a favorable impact on resident performance based on a reduction of missed findings. SSA06-08 Criteria-based Direct Access to Polytrauma Whole-body CT in the Emergency Department Leads to a Dramatic Fall in Use of Plain Radiographs Prior to Whole-body CT at a Major Trauma Centre Sunday, Nov. 27 11:55AM - 12:05PM Room: N226 Awards Student Travel Stipend Award Participants Nikola Tomanovic, MBBS, Brighton, United Kingdom (Presenter) Nothing to Disclose Ahmed Daghir, MRCP, FRCR, Oxford, United Kingdom (Abstract Co-Author) Nothing to Disclose PURPOSE A set of criteria for direct Emergency Department access to polytrauma whole-body CT were introduced in 2013 to help guide clinical decision making and speed up patient imaging in the Emergency Department.This study aims to determine whether the use of criteria based patient selection protocols affects the numbers of plain radiographs performed prior to CT acquisition. METHOD AND MATERIALS A retrospective sample of 60 polytrauma whole-body CT scans, performed over a two month period, at a major trauma centre was analysed in 2012, 2014 and 2015.Criteria-based direct Emergency Department access to polytrauma whole-body CT scans was introduced over 2013 at our hospital, with criteria modified from the patient inclusion criteria for the REACT-2 trial. When the criteria are met the patient proceeds directly to CT without prior discussion with a radiologist.The proportion of patients undergoing a plain radiograph examination of the chest or pelvis prior to CT was compared before (2012) and after (2014 and 2015) introduction of these criteria. RESULTS In 2012, prior to the implementation of the direct ED access to CT protocol, 73% of polytrauma patients (44/60) had a plain chest radiograph and 60% (36/60) had a plain pelvic radiograph prior to CT.Following protocol implementation, however, these numbers reduced drastically. In 2014, 37% of polytrauma patients (22/60) had a plain chest radiograph and 25% (15/60) had a plain pelvic radiograph prior to CT.In 2015, no patients (0/60) had a plain chest radiograph and only 2% (1/60) had a plain pelvic radiograph prior to CT.None of the plain pelvic and chest radiographs in this study yielded any results that were not also noted on the subsequent CT. CONCLUSION Our results show that a criteria-based direct access to CT protocol in the Emergency Department is associated with a dramatic decrease in the use of plain chest and pelvic radiographs prior to whole-body CT. As expected our data also confirm that there were no additional findings shown on plain film over CT. CLINICAL RELEVANCE/APPLICATION The introduction of a “direct access to CT” protocol is associated with a dramatic reduction in the use of plain radiographs before CT. This implies that faster access to CT removes the need for plain radiographs to direct urgent intervention for life-threatening injuries. SSA06-09 National Trends in Imaging Suspected Appendicitis: Current Status Sunday, Nov. 27 12:05PM - 12:15PM Room: N226 Awards Student Travel Stipend Award Participants Victoria F. Tan, MD, Hamilton, ON (Presenter) Nothing to Disclose Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose PURPOSE To assess the current trends in the imaging of suspected appendicitis in adult patients presenting to emergency departments of academic medical centers across our country. METHOD AND MATERIALS A questionnaire was sent electronically to all 17 academic centers in our country to be completed by Emergency Radiology Section Chiefs. The questionnaires were sent over a period of 3 months staring on October 1, 2015. The survey and analysis of the resulting data was approved by the IRB at our institution. RESULTS Fifteen centers (88%) responded to the questionnaire. Eleven respondents (73%) used IV contrast - enhanced CT as the imaging modality of choice in imaging of all patients with suspected appendicitis. Twelve respondents (80%) use ultrasound as the initial modality of choice in imaging pregnant patients with suspected appendicitis. Ten respondents (67%) use ultrasound as the modality of choice in patients younger than 40 years of age. When CT is used, 80% use non-focused CT of the abdomen and pelvis, and 47% of centers routinely use oral contrast. Twelve centers (80%) have ultrasound available 24 hours/7 days a week. At twelve centers (80%), the ultrasound examinations are performed by trained ultrasound technologists. Ten centers (67%) have MRI available 24/7. All fifteen centers (100%) use non-enhanced MRI. However, MRI is used as first modality for the imaging of pregnant patients in only three centers (20%) and as first modality for the imaging of patient younger than 40 years in only one center (7%). CONCLUSION There is heterogeneity in the imaging practice and protocols for patients with suspected appendicitis at our country, which varies depending on patient demographics, resource availability and institutional protocols. CLINICAL RELEVANCE/APPLICATION Imaging trends should be considered to develop a national imaging algorithm to permit standardization across our country. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator ERS-SUA Emergency Radiology Sunday Poster Discussions Sunday, Nov. 27 12:30PM - 1:00PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Moderator) Nothing to Disclose Karen S. Lee, MD, Boston, MA (Moderator) Nothing to Disclose Sub-Events ER200-SDSUA1 Trauma - Attenuation of Abdominal and Pelvic Structures on Computed Tomography in the Setting of Shock Station #1 Awards Student Travel Stipend Award Participants Michael Wasserman, MD, Boston, MA (Presenter) Nothing to Disclose Michael J. Hsu, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Venkata Satyam, Boston, MA (Abstract Co-Author) Nothing to Disclose Tina Shiang, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer Xiao, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Deepan Paul, Boston, MA (Abstract Co-Author) Nothing to Disclose Ahmed Y. El-Araby, MD , West Warwick, RI (Abstract Co-Author) Nothing to Disclose Vaeman Chintamaneni, Boston, MA (Abstract Co-Author) Nothing to Disclose Robert Burns, Boston, MA (Abstract Co-Author) Nothing to Disclose Arthur Baghdanian, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jorge A. Soto, MD, Boston, MA (Abstract Co-Author) Royalties, Reed Elsevier Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE Hypotension is an important marker of a patient’s clinical condition in the setting of trauma. Contrast-enhanced computed tomography of the abdomen and pelvis (CTAP) is an invaluable tool in evaluating blunt or penetrating trauma. The purpose of this study is to investigate the effects of hypotension on the enhancement of a patient’s abdominopelvic structures in the setting of trauma. METHOD AND MATERIALS This HIPAA-compliant, retrospective study performed at our urban academic teaching hospital was approved by the Institutional Review Board (IRB); informed consent was waived.A database of patients, aged 18 and older, receiving CTAP in the setting of blunt or penetrating trauma during 2014 was assembled using our hospital’s EMR. Two cohorts were selected. One cohort comprised of individuals who were hypotensive with a systolic blood pressure of less than 90 on initial presentation to the Emergency Department (ED). The second cohort was comprised of individuals with normal vital signs and lab values on initial presentation to the ED, and without any clinically significant findings on CTAP.Attenuation of the patient’s abdominal and pelvic vascular structures and solid organs were measured in Hounsfield Units (HU). Measurements were obtained in the arterial and portal venous phases. 14 hypotensive individuals were evaluated. Mann Whitney U-tests were used in data analysis. RESULTS In the arterial phase, scanned at 30 seconds, hypotensive individuals demonstrated statistically significant increased attenuation of the aorta, portal vein and renal medulla compared to normotensive individuals. In the portal venous phase, scanned at 70 seconds, hypotensive individuals had significantly decreased attenuation of the renal cortex, spleen, pancreas and liver compared to normotensive individuals. CONCLUSION In the setting of trauma, hypotensive individuals have significant differences in perfusion compared to normotensive individuals, as evidenced by increases in attenuation of the aorta, portal vein and renal medulla in the arterial phase and decreases in attenuation of the renal cortex, spleen, pancreas and liver in the portal venous phase. CLINICAL RELEVANCE/APPLICATION In the setting of trauma, hypotensive individuals have significant differences in perfusion compared to normotensive individuals, which are demonstrated on CTAP. Awareness of these differences may assist in triaging patients and predicting clinical outcomes. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator ER201-SDSUA2 Emergency Ultrasound for Acute Appendicitis: Technical Factors that Influence Follow-up Radiation in Pediatric Patient Populations with Suspected Appendicitis Station #2 Awards Student Travel Stipend Award Participants Joshua Ewell, DO, Norwalk, CT (Presenter) Nothing to Disclose Alicia DeRobertis, MD, Norwalk, CT (Abstract Co-Author) Nothing to Disclose Ichiro Ikuta, MD, MMedSc, Norwalk, CT (Abstract Co-Author) Nothing to Disclose Steven M. Bernstein, MD, Weston, CT (Abstract Co-Author) Nothing to Disclose PURPOSE The purpose of this study is to optimize technical skills to support successful identification of normal and pathologic appendices and to identify technical factors that contribute to non-diagnostic US, with subsequent CT radiation exposure in pediatric patients. METHOD AND MATERIALS All exams were performed by trained radiology residents (RR) or ultrasound technicians (UT). PACS query criteria: date: 01/0112/31/2015; modality: US; procedure: Appendix. 266 studies met criteria. Data-points: performed by RR or UT; time imaging; visualization/non-visualization; subsequent CT and MRI; ave radiation exposure from subsequent imaging; surgical and pathologic concordance; patient demographics. The primary endpoint of the study is to establish exam optimization/best-practice guidelines for diagnostic identification of the appendix during sonographic evaluation. Secondary endpoints include minimizing radiation dose to pediatric patients and pre-empting more costly follow-up MRI imaging. RESULTS Preliminary results (17/266) are provided. Sensitivity (visualized) US = 24%. Specificity (surgically proven) = 50%. Ave time scanning 8 min (vis/non-vis). RR = average of 12 min scanning. UT = average of 5.9 min scanning. RR were twice as likely to identify the appendix (33% of the time versus UT 18%). 6/17 US were followed by CT, with 1 surgically proven appendicitis. Total ave effective dose = 2.8 mSv. 11/17 had no followup imaging, with unrelated discharge diagnoses. The remaining 4 were discharged with diagnoses of abdominal pain NOS. 6/17 were followed by CT. 1 went to surgery with surgical and pathologic concordance. The remaining 5 CTs demonstrated normal appendices on CT. The only abnormal appendix in this group was correctly identified on US. CONCLUSION RR are better at identifying the appendix, suggesting multi-modality correlation and anatomic knowledge may improve success. Low suspicion (screening) ultrasounds from the ED were never positive. Average dose to patients = 2.84 mSv, with 1/6 CT positive for acute appendicitis. CLINICAL RELEVANCE/APPLICATION Preliminary data suggests use of US as a screening tool for nonspecific abdominal pain in the ED is frequent and inappropriate. UT exams may benefit from anatomic review and landmark identification. Further analysis should identify additional factors that contribute to visualization and non-visualization of the appendix and the associated effective radiation doses of subsequent imaging. ER203-SDSUA4 National Trends in Imaging Suspected Appendicitis: Current Status Station #4 Participants Victoria F. Tan, MD, Hamilton, ON (Presenter) Nothing to Disclose Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose PURPOSE To assess the current trends in the imaging of suspected appendicitis in adult patients presenting to emergency departments of academic medical centers across our country. METHOD AND MATERIALS A questionnaire was sent electronically to all 17 academic centers in our country to be completed by Emergency Radiology Section Chiefs. The questionnaires were sent over a period of 3 months staring on October 1, 2015. The survey and analysis of the resulting data was approved by the IRB at our institution. RESULTS Fifteen centers (88%) responded to the questionnaire. Eleven respondents (73%) used IV contrast - enhanced CT as the imaging modality of choice in imaging of all patients with suspected appendicitis. Twelve respondents (80%) use ultrasound as the initial modality of choice in imaging pregnant patients with suspected appendicitis. Ten respondents (67%) use ultrasound as the modality of choice in patients younger than 40 years of age. When CT is used, 80% use non-focused CT of the abdomen and pelvis, and 47% of centers routinely use oral contrast. Twelve centers (80%) have ultrasound available 24 hours/7 days a week. At twelve centers (80%), the ultrasound examinations are performed by trained ultrasound technologists. Ten centers (67%) have MRI available 24/7. All fifteen centers (100%) use non-enhanced MRI. However, MRI is used as first modality for the imaging of pregnant patients in only three centers (20%) and as first modality for the imaging of patient younger than 40 years in only one center (7%). CONCLUSION There is heterogeneity in the imaging practice and protocols for patients with suspected appendicitis at our country, which varies depending on patient demographics, resource availability and institutional protocols. CLINICAL RELEVANCE/APPLICATION Imaging trends should be considered to develop a national imaging algorithm to permit standardization across our country. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator ER101-EDSUA5 Dual Energy CT for Abdominal and Pelvic Trauma: A Pictorial Review Station #5 Awards Certificate of Merit Identified for RadioGraphics Participants Jeremy R. Wortman, MD, Boston, MA (Presenter) Nothing to Disclose Jennifer W. Uyeda, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Urvi P. Fulwadhva, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG TEACHING POINTS 1) Dual energy CT enables a number of applications that can be useful in assessing patients with abdominal and pelvic trauma, including creation of iodine overlay and virtual non-contrast (VNC) images, evaluation of bone marrow edema, and creation of virtual monoenergetic images to accentuate differential enhancement or to reduce metal artifact. 2) Dual energy post-processing in trauma patients can be particularly useful in assessment of active contrast extravasation as well as evaluation of decreased enhancement of abdominal and pelvic viscera, which can be crucial in appropriate management of patients with abdominal and pelvic trauma. 3) Routine dual energy CT imaging and post-processing can be performed in trauma patients in the Emergency Department setting, and can be incorporated into clinical workflow. TABLE OF CONTENTS/OUTLINE 1) Applications of dual energy CT to patients with abdominal and pelvic trauma: review the variety of post-processing applications available with dual energy CT, and how these can benefit assessment of trauma patients2) Case based review of dual energy CT findings in trauma patients3) Future directions and summary Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ERS-SUB Emergency Radiology Sunday Poster Discussions Sunday, Nov. 27 1:00PM - 1:30PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 FDA Discussions may include off-label uses. Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Moderator) Nothing to Disclose Karen S. Lee, MD, Boston, MA (Moderator) Nothing to Disclose Sub-Events ER205-SDSUB2 An Unusual Complication of a Common Finding: Acute Epiploic Appendagitis within Abdominal Wall Hernias - Frequency and Subtypes Station #2 Awards Student Travel Stipend Award Participants Renata R. Almeida, boston, MA (Presenter) Nothing to Disclose Mohammad Mansouri, MD, MPH, Boston, MA (Abstract Co-Author) Nothing to Disclose Ajay K. Singh, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Bernardo C. Bizzo, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Michael H. Lev, MD, Boston, MA (Abstract Co-Author) Consulant, General Electric Company; Institutional Research Support, General Electric Company; Stockholder, General Electric Company; Consultant, MedyMatch Technology, Ltd; Consultant, Takeda Pharmaceutical Company Limited; Consultant, D-Pharm Ltd PURPOSE Acute Epiploic Appendagitis (AEA) as a complication of abdominal wall hernias is poorly studied in the literature. Our aim was to assess the prevalence of AEA within abdominal wall hernias, stratified by hernia subtype. METHOD AND MATERIALS This was an IRB approved HIPAA-compliant retrospective study. Our medical data base was searched for Computed Tomography (CT) cases of abdominal wall hernias occurring between 2003 and 2015, to assess the prevalence of AEA within hernia sacs. Imaging findings on CT were analyzed in the positive cases. Medical records were searched for clinical features and treatment. RESULTS Among 4352 abdominal wall hernias from 4069 patients, 44% (1952/4352) were inguinal, 4.1% (185/4352) Spigelian, 1.5% (64/4352) femoral and 49.4% (2151/4352) ventral hernias. Nine patients had AEA within hernia sacs (Mean age: 70.7 years; 66.7% males). The prevalence of AEA was 0.2% (9/4352) within all abdominal wall hernias, 2.2% within Spigelian (4/185), 0.25% (5/1952) within inguinal, and 0% within femoral and ventral hernias. 77.8% (7/9) of the patients had previous history of anterior abdominal wall surgery. Imaging features included fat stranding (88.9%;8/9), central dot (44.5%;4/9), two inflamed epiploic appendages (33.3%;3/9) and fluid inside the hernia sac (33.3%;3/9). In 66.7% (6/9) only the inflamed appendage was herniated. All the cases presented with local pain. Hernia sacs were incarcerated in 4 cases; strangulated in 1 case, and non-palpable in 4 cases. Hernia treatment was conservative in 55.5% (5/9) and surgical in 44.5% (4/9). CONCLUSION AEA within hernia sacs is rare. This complication is exceedingly unlikely (0%) among ventral or femoral hernias, very unusual in inguinal hernias (0.25%), and most likely to occur within Spigelian hernias (2.2%). Patients were most commonly elderly males with a history of previous abdominal wall surgery. CLINICAL RELEVANCE/APPLICATION Emergency radiologists should be aware that AEA as a complication of abdominal wall hernia is very rare, but when it does occur is most likely within Spigelian hernias. ER206-SDSUB3 Performance of an Ultrasound-First ED Consensus Imaging Algorithm for Suspected Acute Appendicitis Above and Below an Alvarado Score of 3 Station #3 Participants Urvi P. Fulwadhva, MD, Boston, MA (Presenter) Nothing to Disclose Sarah Frasure, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Wendy B. Landman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Amy Hildreth, Boston, MA (Abstract Co-Author) Nothing to Disclose Naomi Schimizu, Boston, MA (Abstract Co-Author) Nothing to Disclose Micheal Stone, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG PURPOSE We recently implemented an US-first consensus-imaging algorithm for suspected acute appendicitis in non-obese patients younger We recently implemented an US-first consensus-imaging algorithm for suspected acute appendicitis in non-obese patients younger than 40 years old. The purpose of this study was to evaluate algorithm performance stratified by Alvarado scores above and below a threshold of 3. METHOD AND MATERIALS Methods and Materials:This HIPAA compliant, IRB approved retrospective study included 277 consecutive ER patients who underwent appendix ultrasound from May 2015 to Feb 2016 based on a new interdepartmental US-first consensus algorithm with CT following inconclusive US. The Alvarado score for all patients was calculated, and patients stratified into scores 3. The patients were then divided based on results of US (normal appendix, appendix not seen no secondary, equivocal US and acute appendicitis). Sensitivity and specificity was calculated. RESULTS Of 111 patients with Alvarado =/<3, US reported a normal appendix in 4, appendix not seen in 92, equivocal findings in 13, and suspected appendicitis in 2. 53 (47.7%) proceeded to CT, 2 (1.8%) to the OR, and none ultimately proved to have appendicitis. 17 (15.3%) had alternative diagnoses explaining symptoms by US, 13 (24%) by CT. The specificity is 98% with NPV of 100%.Of 165 patients with Alvarado >3, US reported a normal appendix in 3, appendix not seen in 99, equivocal findings in 41, and suspected appendicitis in 22. 101 (60%) proceeded to CT, 49 (29%) to the OR, and 44 had pathology proven appendicitis. 27 (16%) had alternative diagnoses explaining symptoms by US, 23 (22%) by CT. Sensitivity and specificity is 44% and 98% with NPV of 82%. CONCLUSION Ultrasound has a higher negative predictive value and should be used as a first tool for evaluation of non-obese young patients with suspected appendicitis with Alvarado score less than 3. Percentage of patients with alternative diagnosis on either CT or US was similar between the two groups. CLINICAL RELEVANCE/APPLICATION Appendix US has higher negative predictive value and should be used as first tool for evaluation of non-obese young patients age less than 40 years with Alvarado score less than 3. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator ER207-SDSUB4 Inadequate Clinical Information in Emergency Radiology Consultations - Does It Really Affect the Error Rate or Is It Merely a Bugbear? Station #4 Participants Anjali Agrawal, MD, Delhi, India (Presenter) Nothing to Disclose Arjun Kalyanpur, MD, Bangalore, India (Abstract Co-Author) CEO, Teleradiology Solutions Pvt Ltd PURPOSE The frustration of receiving inadequate clinical information during a referral is well known to any practicing radiologist. We sought to determine if there was any correlation between the quality of clinical information and the types of errors in our emergency teleradiology practice. METHOD AND MATERIALS We maintain a record of cases sent for quality assurance (QA) review by our client radiology practices. These comprise less than 1% of all cases and are scored as per ACR RADPEER guidelines, ranging from 1 (no error) to 4 (obvious miss), further denoted as “a” (clinically insignificant) or “b” (clinically significant). In 831 cases flagged for QA review, we additionally scored the quality of clinical information – category 1 (inadequate), 2 (adequate), 3 (detailed), for the study type ordered, and without knowledge of the missed findings or the QA grade. Similarly, we also scored 304 cases where no QA was flagged. Chi-square tests and regression models were used to determine the associations between quality of clinical information and radiologic error. RESULTS Surprisingly, detailed histories (Category 3) were less frequent in the cases without QA than those with QA or error (p < 0.01). There was no significant influence of clinical information score upon QA category. More history did not reduce the rates of obvious errors or any errors. Stronger effects were seen for the type of study, with MR studies being significantly associated with increased rates of clinically significant (ACR “b”) errors (p=0.008). The level of clinical information was not associated with any reduction in the proportion of significant error (ACR2b, 3b, 4b), when compared to no error. CONCLUSION It is likely that experienced radiologists do not require much clinical information to reach an accurate radiological diagnosis in the emergent setting with a relatively well defined mix of cases. Whether this is also true for radiologists-in-training or those in the early years of practice needs to be tested. CLINICAL RELEVANCE/APPLICATION Perceived inadequate clinical information by radiologists does not translate to increased rates of radiologic error, at least in an emergency radiology setting with experienced radiologists. ER112-EDSUB5 Imaging of the Perineum in the Emergency Setting: A Pictorial Review Station #5 Awards Certificate of Merit Identified for RadioGraphics Participants Jihee Choe, MD, Boston, MA (Presenter) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG Bharti Khurana, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer W. Uyeda, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1) The perineal area can be easily overlooked by radiologists as pathologies are relatively infrequent and potentially complicated. 2) The anatomy of the perineum is complex. It is important for radiologists to be familiar with relevant anatomy of the perineum for accurate identification of origin and extent of the disease. 3) Various imaging modalities can be used to evaluate the perineum; however, CT is most commonly utilized in the acute setting. The widespread availability and rapid acquisition afforded by CT allows for the evaluation of acute perineal pathologies such as traumatic injury, infectious/inflammatory process, neoplastic process, and foreign body. TABLE OF CONTENTS/OUTLINE 1) Review anatomy of the perineum 2) Discuss role of the imaging modalities in evaluating the perineum3) Illustrate characteristic imaging features of common traumatic perineal injuries encountered in the emergency setting 4) Demonstrate various cases and imaging features of nontraumatic pathologies including infectious/inflammatory processes, neoplasms, and foreign bodies Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator Bharti Khurana, MD - 2014 Honored Educator RC108 Emergency Neuroradiology (An Interactive Session) Sunday, Nov. 27 2:00PM - 3:30PM Room: N227B NR CT MR ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Sub-Events RC108A Non-traumatic Subarachnoid Hemorrhage Participants Diego B. Nunez JR, MD, MPH, Boston, MA (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Analyze the various causes, patterns of distribution and imaging features of non-traumatic subarachnoid hemorrhage. 2) Identify the different diagnostic pitfalls encountered in the initial assessment of patients with suspected subarachnoid hemorrhage. 3) Assess the contribution of additional imaging (CTA, MR, DSA) as integral part of the admitting evaluation of patients with subarachnoid hemorrhage. ABSTRACT RC108B CT and MRI of Neck Infections Participants Wayne S. Kubal, MD, Tucson, AZ (Presenter) Stockholder, Stryker Corporation; Stockholder, Sarepta Therapeutics Inc; Stockholder, CVS Health Corporation; Stockholder, Gilead Sciences, Inc; Author, Reed Elsevier; Editor, Reed Elsevier LEARNING OBJECTIVES 1) To diagnose neck infection on CT and MR. 2) To characterize the nature and the location of the infection. 3) To appreciate the complications that may result from the infection. ABSTRACT Active Handout:Wayne Scott Kubal http://abstract.rsna.org/uploads/2016/16000635/ACTIVE Handout for Course RC108B.pdf RC108C CT and MRI of Spine Infections Participants A. Orlando Ortiz, MD, MBA, Mineola, NY (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Review the epidemiology and pathophysiology of spine infection. 2) Focus on making the diagnosis of infectious spondylitis utilizing: Clinical findings, Imaging findings, Biopsy. 3) Distinguish infectious spondylitis from other radiographic mimics. RC131 Interventional Stroke Treatment: Practical Techniques and Protocols (An Interactive Session) Sunday, Nov. 27 2:00PM - 3:30PM Room: S103AB ER NR IR AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Joshua A. Hirsch, MD, Boston, MA (Moderator) Consultant, Medtronic plc; Data Safety Monitoring Board, Johnson & Johnson; LEARNING OBJECTIVES 1) Describe the diagnostic evaluation and decision making algorithms leading to urgent endovascular treatment of acute stroke. 2) Review endovascular techniques for the treatment of acute stroke from microcatheter set up to intraarterial thrombolysis to mechanical thrombectomy. 3) Discuss case examples of endovascular treatment including patient selection, technique, and pitfalls. ABSTRACT Rapid advances in the evaluation, selection, treatment and management of the acute stroke patient necessitates an ongoing educational event highlighing the newest information, techniques and strategies for obtaining the best outcomes for our patients. In this session, all of these topics will be covered in a practical "how to" and case based approach which is designed to help the practitioner implement best practices. The course is useful for those performing imaging, treatment or both. Analysis of the latest ongoing trials, devices and techniques will be presented. Endovascular tips and tricks will be discussed, as well as pitfalls in the treatment of these patients. Sub-Events RC131A Devices and Data that Support IA Treatment as the Standard of Care for Ischemic Stroke Participants Allan L. Brook, MD, Bronx, NY (Presenter) Nothing to Disclose LEARNING OBJECTIVES View learning objectives under main course title. RC131B Optimizing Patient Selection with Imaging Participants Ramon G. Gonzalez, MD, PhD, Boston, MA (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Understand the essential ischemic stroke physiology parameters that are essential in selecting patients for endovascular treatment of a large vessel occlusion. 2) Be familiar with the imaging methods that can measure ischemic stroke physiology parameters and their relative accuracy. 3) Use the best available evidence, recognize the optimal imaging approach to select patients with acute ischemic stroke for endovascular treatment. RC131C Minimally Invasive Surgery for ICH - The Next Frontier Participants David J. Fiorella, MD, PhD, Stony Brook, NY (Presenter) Institutional research support, Siemens, AG; Institutional research support, Terumo Corporation; Institutional research support, Sequent Medical, Inc; Consultant, Medtronic plc; Consultant, Penumbra, Inc; Consultant, Sequent Medical, Inc; Consultant, Johnson & Johnson; Stockholder, Vascular Simulations LLC; Consultant, Vascular Simulations LLC; Owner, TDC Technologies; Owner, CVSL; Royalties, Johnson & Johnson; ; ; LEARNING OBJECTIVES 1) Understand the essential ischemic stroke physiology parameters that are essential in selecting patients for endovascular treatment of a large vessel occlusion. 2) Be familiar with the imaging methods that can measure ischemic stroke physiology parameters and their relative accuracy. 3) Use the best available evidence, recognize the optimal imaging approach to select patients with acute ischemic stroke for endovascular treatment. ABSTRACT Properly selected patients with acute ischemic stroke caused by large vessel occlusion (LVO) may be effectively and safely treated endovascularly with modern thrombectomy devices. We have developed a high-precision imaging tool for selecting such patients. It is an experience and evidence-based clinical triage tool that uses advanced imaging to identify INDIVIDUAL patients most likely to benefit from endovascular stroke therapy. It was based on over a decade of using advanced imaging (CT, CTA, CT perfusion, DWI, MR perfusion) in acute stroke patients and a critical review of the literature and has been validated in clinical trials. The approach focuses on answering the following key questions using modern imaging: 1. Is there a hemorrhage? Noncontrast CT 2. Is there an occlusion of the distal ICA and/or proximal MCA? CTA 3. Is irreversible brain injury below a specific threshold (e.g. <70ml)? DWI Perfusion imaging is not employed unless patients cannot undergo MRI, or they do not meet the criteria for intervention. Investigations to understand the reasons for the unsuitability of perfusion CT to substitute for DWI have revealed theoretical and practical shortcomings of CTP. A major problem is the low signal-to-noise (SNR) ratio of CT perfusion that results in a poor contrast-to-noise (CNR) ratio in severely ischemic brain. In a comparison between DWI and CTP in over 50 consecutive patients with LVA, Schaefer, et al. showed that the mean CNR of DWI was >4 while it was <1 for CTP derived CBF. The poor CNR results in large measurement error: using Bland-Altman analyses it was found that the 95% confidence interval was ~+/- 50 ml for ischemic lesion volume measurements in individual patients. The Cleveland Clinic adopted a nearly identical algorithm and their results were published. They reported that after the new algorithm was adopted, there was a ~50% reduction in mortality and a ~3-fold increase in good outcomes, despite a ~50% decrease in the number of procedures. A recent prospective observational trial at the MGH using stentrievers and this imaging approach demonstrated >50% favorable outcomes (mRS 0-2) that is similar to recent randomized clinical trials. However, only 3 patients were evaluated for every patient that was treated, a screening to treatment ratio that is much lower than in recently published clinical trials.1. Gonzalez RG, Copen WA, Schaefer PW, Lev MH, Pomerantz SR, Rapalino O, et al. The Massachusetts General Hospital acute stroke imaging algorithm: an experience and evidence based approach. Journal of neurointerventional surgery. 2013;5 Suppl 1:i7-12. 2. Wisco D, Uchino K, Saqqur M, Gebel JM, Aoki J, Alam S, et al. Addition of hyperacute MRI AIDS in patient selection, decreasing the use of endovascular stroke therapy. Stroke; a journal of cerebral circulation. 2014;45(2):467-72. 3. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986 Feb 8;1(8476):307-10.4. Schaefer PW, Souza L, Kamalian S, Hirsch JA, Yoo AJ, Kamalian S, Gonzalez RG, Lev MH. Limited reliability of computed tomographic perfusion acute infarct volume measurements compared with diffusion-weighted imaging in anterior circulation stroke. Stroke. 2015 Feb;46(2):419-24. ED004-MO Emergency Radiology Monday Case of the Day Monday, Nov. 28 7:00AM - 11:59PM Room: Case of Day, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose David Dreizin, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Manickam Kumaravel, MD, FRCR, Houston, TX (Abstract Co-Author) Nothing to Disclose Constantine A. Raptis, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose David D. Bates, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thomas Battey, Timonium, MD (Abstract Co-Author) Nothing to Disclose Nicholas M. Beckmann, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose Matt H. Kwon, Mineola, NY (Abstract Co-Author) Nothing to Disclose Aderonke Ramos, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1) Recognize key imaging findings on multimodality imaging of emergency/trauma patients. 2) Develop differential diagnosis based on the clinical information and imaging findings. 3) Recommend appropriate management including image-guided interventions. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator RC205 Neuroradiology Series: Stroke Monday, Nov. 28 8:30AM - 12:00PM Room: N227B NR ER AMA PRA Category 1 Credits ™: 3.25 ARRT Category A+ Credits: 4.00 FDA Discussions may include off-label uses. Participants Ajay Gupta, MD, New York, NY (Moderator) Consultant, Biomedical Systems; Howard A. Rowley, MD, Madison, WI, ([email protected] ) (Moderator) Research Consultant, Bracco Group Research Consultant, Guerbet SA Research Consultant, General Electric Company Consultant, F. Hoffmann-La Roche Ltd Consultant, W.L. Gore & Associates, Inc Consultant, Lundbeck Group Sub-Events RC205-01 Stroke Systems of Care and Implications for the Radiologist Monday, Nov. 28 8:30AM - 9:00AM Room: N227B Participants Edward C. Jauch, MD, MS, Charleston, SC (Presenter) Research Support, F. Hoffmann-La Roche Ltd; Research Support, Ischemia Technologies; Research Support, Medtronic plc; Research Support, Stryker Corporation; Research Support, Penumbra, Inc; Research Support, NoNO, Inc; Research Support, ZZ Biotech, LLC; ; RC205-02 Prediction of Treatment Response to IV Thrombolysis in Acute Ischemic Stroke Patients using CT Perfusion-Based Wavelet-Transformed Angiography Monday, Nov. 28 9:00AM - 9:10AM Room: N227B Participants Wolfgang G. Kunz, MD, Munich, Germany (Abstract Co-Author) Nothing to Disclose Matthias Fabritius, Munich, Germany (Abstract Co-Author) Nothing to Disclose Lukas Havla, Munich, Germany (Abstract Co-Author) Nothing to Disclose Birgit B. Ertl-Wagner, MD, Munich, Germany (Abstract Co-Author) Board Member, Koninklijke Philips NV; Board Member, Bracco Group; Board Member, Springer Science+Business Media; Consultant, MMI Munich Medical International GmbH; Consultant, Koninklijke Philips NV; Consultant, Springer Science+Business Media; Consultant, Thieme Medical Publishers, Inc; Consultant, Bracco Group; Institutional Research Grant, Eli Lilly and Company; Institutional Research Grant, F. Hoffmann-La Roche Ltd; Institutional Research Grant, Guerbet SA; Institutional Research Grant, Merck KGaA; Institutional Research Grant, Bayer AG; Institutional Research Grant, Novartis AG; Speaker, Siemens AG; Author, Springer Science+Business Media; Author, Thieme Medical Publishers, Inc; Author, Bracco Group; Royalties, Springer Science+Business Media; Royalties, Thieme Medical Publishers, Inc; Stockholder, Siemens AG; Travel support, Siemens AG; Wieland H. Sommer, MD, Munich, Germany (Abstract Co-Author) Founder, QMedify GmbH Kolja M. Thierfelder, MD,MSc, Munich, Germany (Presenter) Nothing to Disclose Maximilian F. Reiser, MD, Munich, Germany (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the predictive value of vessel occlusions that were only detected using CT perfusion-based wavelet-transformed angiography (waveletCTA) on morphologically determined response to IV thrombolysis. METHOD AND MATERIALS In this IRB-approved study, patients out of a retrospective cohort of 929 consecutive subjects who had undergone multiparametric CT including whole-brain CT perfusion due to suspected ischemic stroke were included. Inclusion criteria were: (1) significant cerebral blood flow (CBF) deficit, (2) no evidence of single phase CTA (spCTA) occlusion, and (3) acute ischemic non-watershed infarction as confirmed by follow-up imaging. waveletCTA defines angiographic signal by best fitting of time-attenuation curves to a generic contrast bolus curve in each voxel as described before. Two blinded and experienced readers analyzed the waveletCTA images with respect to presence and location of vessel occlusions. Morphologic outcome was defined as relative final infarction volume using the ratio (final infarction volume) / (CBF deficit volume), of which smaller values were considered favorable. Multivariate linear regression analyses were performed to identify independent associations. RESULTS Seventy-six patients (mean age 71.6 years, SD 12.7) fulfilled the inclusion criteria. Among all 76 patients with unremarkable spCTA, 39 (51.3%) patients showed an occlusion on waveletCTA (vascular territories: MCA 34, PCA 2, ACA 1, SCA 2). Patient subgroups receiving IV thrombolysis (IVT) (N=39) or supportive care (SC) (N=37) showed no statistically significant difference in age, sex, time from symptom onset, early infarction signs, CTP mismatch, waveletCTA-detected occlusions or NIHSS on admission (all p>0.05). In patients treated with IVT, linear regression analysis showed that the presence of a waveletCTA-detected occlusion was an independent predictor of a favorable morphologic outcome (beta=-0.524; p=0.015), while it failed to predict morphologic outcome in patients receiving SC (beta=0.046; p=0.812). CONCLUSION The presence of an spCTA occult vessel occlusion detected using waveletCTA is an independent predictor of a favorable response to IVT in terms of a smaller relative final infarction volume. CLINICAL RELEVANCE/APPLICATION waveletCTA has the potential to contribute to decision making in acute stroke as occlusions that are detected with this technique waveletCTA has the potential to contribute to decision making in acute stroke as occlusions that are detected with this technique (but not on spCTA) seem to predict a more favorable response to IVT. RC205-03 Cost-Utility Analysis of MR Selection with DWI for Thrombectomy in Proximal Large Vessel Occlusion Stroke Monday, Nov. 28 9:10AM - 9:20AM Room: N227B Awards Student Travel Stipend Award Participants Brian C. Cristiano, MD, Loma Linda, CA (Presenter) Nothing to Disclose Rajeev Nowrangi, MD,MPH, Loma Linda, CA (Abstract Co-Author) Nothing to Disclose Udo Oyoyo, Loma Linda, CA (Abstract Co-Author) Nothing to Disclose Matthew D. Pond, MD, Loma Linda, CA (Abstract Co-Author) Nothing to Disclose Somnath Basu, MD, Toluca Lake, CA (Abstract Co-Author) Nothing to Disclose J. Paul Jacobson, MD, Loma Linda, CA (Abstract Co-Author) Shareholder, Genelux Corporation PURPOSE Mechanical thrombectomy improves outcomes for patients with proximal large vessel occlusion (LVO) stroke. Treatment selection strategies however remain poorly defined. At our institution we have observed favorable results among patients with small presenting DWI core volume regardless of time from onset. Here we leveraged data from an institutional stroke database to model the cost and effectiveness of a time-independent, MR-driven treatment selection strategy compared with the present standard of care, which emphasizes time from onset and excludes late candidates. METHOD AND MATERIALS A decision-analysis model was constructed using outcomes, probabilities and cost data from published sources and an institutional stroke database. Willingness to pay (WTP) was set at $50k/QALY. Two selection strategies were modeled: (1) treat all early LVO patients if reasonable to achieve access within 6 hours of onset (standard of care), (2) treat all LVO patients with small presentation core infarct (≤50 mL diffusion restriction on MRI), regardless of time from onset. Probabilistic and one-way sensitivity analyses were performed. RESULTS Using a US cost structure, MR screening dominates the standard-of-care, with improved QALYs (0.42 v. 0.40) and reduced costs ($33,800 v. $35,410). In a probabilistic sensitivity analysis, MR screening was more cost-effective in 99% of simulations. In a separate Monte Carlo simulation using a UK cost environment, MR screening was more cost-effective 89% of the time. CONCLUSION A time-independent, MR-driven treatment selection strategy is more cost effective than the current standard of care, which emphasizes time from symptom onset as the major criterion for selection. CLINICAL RELEVANCE/APPLICATION Improved outcomes and reduced costs may be achievable in proximal LVO stroke by selecting patients for thrombectomy based on presenting DWI infarct volume rather than time from onset. RC205-04 Machine Learning in the Detection of Brain Infarct on Computed Tomography Monday, Nov. 28 9:20AM - 9:30AM Room: N227B Awards Student Travel Stipend Award Participants Ashley Knight-Greenfield, MD, New York, NY (Presenter) Nothing to Disclose Lohendran Baskaran, New York, NY (Abstract Co-Author) Nothing to Disclose Praneil Patel, MD, Philadelphia, PA (Abstract Co-Author) Nothing to Disclose Tong Zhang, Piscataway, NJ (Abstract Co-Author) Nothing to Disclose Peng Sun, Piscataway, NJ (Abstract Co-Author) Nothing to Disclose Qi Chang, Piscataway, NJ (Abstract Co-Author) Nothing to Disclose Hooman Kamel, MD, New York, NY (Abstract Co-Author) Speaker, F. Hoffmann-La Roche Ltd Ajay Gupta, MD, New York, NY (Abstract Co-Author) Consultant, Biomedical Systems; James K. Min, MD, New York, NY (Abstract Co-Author) Speakers Bureau, General Electric Company Advisory Board, General Electric Company Stockholder, General Electric Company Consultant, Koninklijke Philips NV PURPOSE To utilize a deep learning technique in which a computer is trained and tested in the detection of infarct on computed tomography (CT). METHOD AND MATERIALS 56 head CT scans from an IRB-approved institutional stroke database were selected at random and uploaded to an annotation system. A total of 1482 axial CT slices were annotated by a single radiologist. Brain centerline was drawn, and brain area and infarct area were manually traced on CT slices. Categories of annotation included presence of infarct, chronicity of infarct, type of infarct (ischemic/hemorrhagic), and sidedness of infarct. CT slices from 47 scans were utilized as a training set, while slices from 9 scans were used as a test set. In order to train the computer, 60 x 60 pixel sections, or patches, were utilized with a 10 pixel stride for a total of 1.8 million training patches and 360,000 test patches. Patches were input into a max-pooling convolutional neural network, a type of deep learning architecture, for the purposes of training and testing the computer. Sensitivity, specificity, and receiver operating characteristic (ROC) analysis for pixel accuracy was performed on the test set. Heat maps were generated by the computer denoting possibility of infarct. RESULTS 387 (31%) slices were positive for infarct in the training set, 223 (58%) of which were acute, while 76 (30%) slices were positive in the test set, 35 (46%) of which were acute. Increased accuracy for infarct detection by the computer was observed on sequential testing cycles. Sensitivity for infarct detection in the test set was 76.6%, with specificity of 90.25%. ROC analysis revealed area under the curve of 0.93. CONCLUSION We demonstrated that a deep learning technique can be used as a tool to train computers in infarct detection, with ultimate selflearning capability. With future optimization of this learning process, we hope to develop a highly accurate assistive tool for radiologists in the detection of infarct. CLINICAL RELEVANCE/APPLICATION Early stages of brain infarction can oftentimes be difficult to detect with computed tomography, and thus an assistive tool, such as a computer, would be of use to radiologists. RC205-05 A Simplified Alberta Stroke Program Early CT Score (sASPECTS) for Prognostication and Treatment Triage of Anterior Circulation Acute Ischemic Stroke Monday, Nov. 28 9:30AM - 9:40AM Room: N227B Participants Seyedmehdi Payabvash, MD, San Francisco, CA (Presenter) Nothing to Disclose Siamak Noorbaloochi, Minneapolis, MN (Abstract Co-Author) Nothing to Disclose Adnan I. Qureshi, MD, Minneapolis, MN (Abstract Co-Author) Nothing to Disclose PURPOSE To develop a predictive tool based on the topology of early ischemic changes on the admission noncontrast CT scan of anterior circulation ischemic stroke. METHOD AND MATERIALS The study cohort was derived from the ALIAS (Albumin in Acute Stroke) multicenter trials. Patients with admission noncontrast CT scan and anterior circulation stroke were included. Two expert readers graded ischemic change on admission CT scan using the Alberta Stroke Program Early CT Score (ASPECTS). A stepwise penalized logistic regression determined those components of the ASPECTS on admission scans that were independent predictors of favorable outcome – defined by 3-month modified Rankin Scale (mRs) score ≤2. Follow-up 24-hour CT/MRI scans were reviewed for evidence of intracranial hemorrhage (ICH). RESULTS A total of 1115 patients were included. The ischemic changes of the caudate, lentiform nucleus, insula, and M5 components of ASPECTS on admission CT scan were independent predictors of favorable outcome based on stepwise penalized logistic regression. A 0-to-4 point simplified ASPECTS (sASPECTS) was developed including these components. There was no significant difference between the ASPECTS and sASPECTS in prediction of clinical outcome (p=0.738). Among patients with sASPECTS≥1, the rate of favorable outcome was higher in patients with IV thrombolytic therapy (501/837, 59.9%) versus those without treatment (91/183, 49.7%, p=0.013); whereas, among patients with sASPECTS of 0, IV thrombolysis was not associated with improved clinical outcome. Moreover, patients with sASPECTS of 0 were more likely to develop symptomatic ICH (odds ratio=2.62, 95% confidence interval: 1.49–4.62), compared to those with sASPECTS≥1 (p=0.004). CONCLUSION In anterior circulation stroke patients, topographic assessment of acute ischemic changes in the caudate, lentiform nucleus, insula, and M5 (as part of sASPECTS) can predict clinical outcome as accurately as the ASPECTS. Moreover, sASPECTS may identify those patients with favorable outcome associated with thrombolytic therapy, and those who are at risk of developing symptomatic ICH. CLINICAL RELEVANCE/APPLICATION A semi-quantitative assessment of central MCA territory early ischemic changes can assist stroke treatment triage by identifying patients who may benefit from IV tPA therapy and those at risk of developing symptomatic ICH. RC205-06 One Year Out from the 2015 Trials- Where does Endovascular Treatment Stand? Monday, Nov. 28 9:40AM - 10:10AM Room: N227B Participants Philip M. Meyers, MD, New York, NY (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) The participant will appreciate the significance of recent endovascular stroke trials demonstrating safety and efficacy of mechanical thromboectomy for treatment of acute large artery ischemic stroke. 2) The participant will understand the context in which additional NIH stroke trials address outstanding questions about endovascular treatment of acute ischemic stroke in a broader patient population. ABSTRACT Stroke remains a leading cause of adult death and disability throughout the world. During the last two years, a series of randomized, controlled trials comparing mechanical thrombo-embolectomy plus medical therapy to medical therapy alone have demonstrated superior clinical outcomes with rapid revascularization using catheter-based techniques. In carefully selected patients, the odds of recovery are better. These studies show benefit most often when treatment is performed as quickly as possible and within 6 hours of stroke onset. For a variety of reasons, many stroke victims – perhaps even a majority – present outside of the conventional time window. With imaging to assess directly or indirectly for cerebral viability, identification of additional treatment candidates is possible. This is an important goal of the next set of ischemic stroke trials. LEARNING OBJECTIVES 1) The participant will appreciate the significance of recent endovascular stroke trials demonstrating safety and efficacy of mechanical thromboectomy for treatment of acute large artery ischemic stroke. 2) The participant will understand the context in which additional NIH stroke trials address outstanding questions about endovascular treatment of acute ischemic stroke in a broader patient population. ABSTRACT Stroke remains a leading cause of adult death and disability throughout the world. During the last two years, a series of randomized, controlled trials comparing mechanical thrombo-embolectomy plus medical therapy to medical therapy alone have demonstrated superior clinical outcomes with rapid revascularization using catheter-based techniques. In carefully selected patients, the odds of recovery are relatively good. These studies show benefit most often when treatment is performed as quickly as possible and within 6 hours of stroke onset. For a variety of reasons, many stroke victims – perhaps even a majority – present outside of the conventional time window. With imaging to assess directly or indirectly for cerebral viability, identification of additional treatment candidates is possible. This is an important goal of the next set of ischemic stroke trials. RC205-07 Excluded Patients from the 2015 Trials: The Silent Majority Monday, Nov. 28 10:20AM - 10:50AM Room: N227B Participants Achala S. Vagal, MD, Cincinnati, OH, ([email protected] ) (Presenter) Research Grant, F. Hoffmann-La Roche AG LEARNING OBJECTIVES 1) Recognize the imaging features of patients who were included in the 2015 endovascular trial. 2) Discuss which groups of patients were excluded from the 2015 trials. 3) Discuss the current evidence and future research directions in these excluded subgroups. ABSTRACT RC205-08 Acute Reperfusion without Recanalization: Assesment of Collaterals Using Perfusion-Weight MRI Monday, Nov. 28 10:50AM - 11:00AM Room: N227B Participants Leila Chamard, BRON, France (Presenter) Nothing to Disclose Nikolaos Makris, BRON, France (Abstract Co-Author) Nothing to Disclose Tae-Hee Cho, MD, Bron, France (Abstract Co-Author) Nothing to Disclose Marc Hermier, MD, PhD, Lyon, France (Abstract Co-Author) Nothing to Disclose Roxana R. Ameli, Bron, France (Abstract Co-Author) Nothing to Disclose Guy Louis-Tisserand, MD, Bron Cedex, France (Abstract Co-Author) Nothing to Disclose Norbert Nighoghossian, MD, PHD, Lyon, France (Abstract Co-Author) Nothing to Disclose Yves Berthezene, MD, PhD, Bron, France (Abstract Co-Author) Nothing to Disclose PURPOSE Acute reperfusion despite persistent vessel occlusion can occur in about 30% of patients. Retrograde reperfusion through leptomeningeal collaterals may explain this phenomenom. The present study evaluated relationship between colaterals and reperfusion and clinical outcome in acute stroke. METHOD AND MATERIALS From a multicenter prospective database (I-KNOW), 46 patients with MR-angiography-visible occlusion and in whom both reperfusion and recanalization were assessed within 6 hours of symptoms onset where identified. Maps of collateral flow at arterial, capillary and late veinous phases were automatically generated from dynamic susceptibility-contrast perfusion images through inter-frame registration, baseline signal substraction and temporal summation, and graded according to the American Society of Interventional and Therapeutic Neuroradiology system. Flow direction (anterograde vs retrograde) was visually assessed from the dynamic images. The acute evolution of collateral grades was evaluated against the reperfusion and recanalization status. RESULTS Acute reperfusion was associated with better collateral grades at baseline (OR: 36.02; 95% CI: 8.5-207.7; p<0.001). Among patients without recanalization, collateral grades significantly improved between admission and acute follow-up in reperfused patients (OR: 4.57; 95% CI: 1.1-22.7; p=0.048), but not in those without reperfusion (OR: 1.34; 95% CI: 0.4-4.5; p=0.623). Acute reperfusion was associated with favourable clinical outcome, regardless of flow direction. CONCLUSION Acute reperfusion without recanalization is related to a significant improvement of retrograde collateral flow. CLINICAL RELEVANCE/APPLICATION Collateral status is usefull for management in patient with acute stroke RC205-10 MR Perfusion to Determine the Status of Collaterals in Patients with Acute Ischemic Stroke: Look Beyond Perfusion Time-Maps Monday, Nov. 28 11:10AM - 11:20AM Room: N227B Participants Kambiz Nael, MD, New York, NY (Presenter) Research Consultant, Olea Medical James R. Knitter, BS, Tucson, AZ (Abstract Co-Author) Nothing to Disclose Amish H. Doshi, MD, New York, NY (Abstract Co-Author) Nothing to Disclose J. Mocco, MD, Nashville, TN (Abstract Co-Author) Nothing to Disclose Reade Deleacy, MD, New York, NY (Abstract Co-Author) Nothing to Disclose Joshua Bederson, MD, New York, NY (Abstract Co-Author) Nothing to Disclose Thomas P. Naidich, MD, New York, NY (Abstract Co-Author) Nothing to Disclose PURPOSE MR perfusion time-maps show delayed perfusion but are unable to differentiate antegrade from collateral flow if used alone. Using a multiparametric approach, we aimed to identify perfusion parameter/s that can represent the extent of collaterals in comparison to angiographic findings in patients with acute ischemic stroke (AIS). METHOD AND MATERIALS AIS patients with anterior circulation proximal occlusion who had baseline MR perfusion and cerebral angiography were evaluated. MR perfusion data were processed using Bayesian method to generate arterial tissue delay (ATD) maps at thresholds of 2, 6 seconds. The volume of delayed perfusion (Vol-ATD2sec), critical hypoperfusion (Vol-ATD6sec), and hypoperfusion (Vol-ATD 2sec6sec) in addition to corresponding values of rCBV and rCBF were calculated using volume-of-interest (VOI) analysis. Collateral status was dichotomized to poor (ASITN/SIR 0-2) or good (ASITN/SIR 3–4) using baseline cerebral angiography. Statistical analysis was performed using multivariate logistic regression and receiver operating characteristic (ROC) analysis. RESULTS In 37 patients included, 20 (54%) had good collaterals using cerebral angiography. After controlling for age, baseline NIHSS and infarct volume, multivariate logistic regression analysis identified rCBV (p=0.001) and hypoperfused volume (Vol-ATD 2sec-6sec) (p=0.01), but not rCBF (p=0.08), Vol-ATD 2sec (p=0.3) or Vol-ATD 6sec (p=0.07), as independent predictors of good collaterals. For rCBV, ROC analysis showed the greatest AUC (0.89) at the threshold > 2.1 with sensitivity/specificity of 85%/90%. For Vol-ATD 2sec-6sec, ROC analysis showed the greatest AUC (0.78) at a threshold > 51 ml with sensitivity/specificity of 70%/82%. Hypoperfused tissue volume (Vol-ATD 2sec-6sec) multiplied by its rCBV, termed hypoperfused tissue collateral index, remained an independent predictor of good collaterals, with improved diagnostic accuracy over each measure alone (AUC: 0.96 at a threshold > 90, sensitivity/specificity of 91%/100%). CONCLUSION Hypoperfused tissue collateral index defined as hypoperfused volume (Vol-ATD 2sec-6sec) x rCBV is a new perfusion index with diagnostic accuracy of 96% compared to angiographic findings to predict status of collaterals. CLINICAL RELEVANCE/APPLICATION In patients with AIS, evaluation of collateral flow using baseline imaging can have therapeutic and prognostic implications. RC205-12 Don't Fall for These Stroke Mimics Monday, Nov. 28 11:30AM - 12:00PM Room: N227B Participants Pamela W. Schaefer, MD, Boston, MA (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Recognize the key neuroimaging characteristics of acute ischemic stroke and common stroke mimics. 2) Use pertinent imaging features and key clinical factors to differentiate acute ischemic stroke from stroke mimics. 3) Discuss the utility of various imaging techniques to distinguish stroke mimics from acute ischemic stroke. ABSTRACT This talk will discuss the key imaging features of common stroke mimics and how to distinguish them from acute ischemic stroke. Entities resembling acute ischemic stroke due to restricted diffusion - such as seizures, tranisent global amnesia, hypoglyycemia, central pontine myelinolysis and other metaqboilc disorders, methotrexate and other drug toxicities, diffuse axonal injury, some metastases, fat emboli, demyelinative lesions, some products of hemorrhage, and some infections - will be discussed. Entities resembling subacute stroke with vasogenic edema and elevated diffusion - such as venous thrombosis, hyperperfusion syndrome, and PRES - will be presented. Entities with gyrifrom enhancement resembling subacute stroke - such as some neoplasms, infectious processes and inflammatory processes - will be discussed. RC208 Emergency Radiology Series: Current Imaging of the Acute Abdomen Monday, Nov. 28 8:30AM - 12:00PM Room: S102AB GI CT MR ER AMA PRA Category 1 Credits ™: 3.50 ARRT Category A+ Credits: 4.00 FDA Discussions may include off-label uses. Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON, ([email protected]) (Moderator) Nothing to Disclose Zachary S. Delproposto, MD, Ann Arbor, MI (Moderator) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Moderator) Nothing to Disclose LEARNING OBJECTIVES 1) To discuss common and uncommon causes of acute abdomen relevant to emergency imagers. ABSTRACT Sub-Events RC208-01 CT of Gastroduodenal Ulcers and Related Disorders Monday, Nov. 28 8:30AM - 9:00AM Room: S102AB Participants Perry J. Pickhardt, MD, Madison, WI, ([email protected] ) (Presenter) Co-founder, VirtuoCTC, LLC; Stockholder, Cellectar Biosciences, Inc; Stockholder, SHINE Medical Technologies, Inc; Research Grant, Koninklijke Philips NV LEARNING OBJECTIVES 1) Comprehend the underestimated role of CT in diagnosing gastroduodenal ulcer disase. 2) Analyze the CT findings of gastroduodenal ulcers, related conditions, and differential diagnosis. 3) Apply these CT features into daily clinical practice to affect patient outcomes. ABSTRACT Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Perry J. Pickhardt, MD - 2014 Honored Educator RC208-02 Diagnosing Gastric Band Slippage in the Emergency Department: Performance of 4 Imaging Signs on Both Radiography and Computed Tomography Monday, Nov. 28 9:00AM - 9:10AM Room: S102AB Participants Michael S. Furman, MD, Providence, RI (Presenter) Nothing to Disclose David W. Swenson, MD, Brooklyn, CT (Abstract Co-Author) Nothing to Disclose Kevin J. Chang, MD, Sharon, MA (Abstract Co-Author) Nothing to Disclose David J. Grand, MD, Providence, RI (Abstract Co-Author) Nothing to Disclose Albert A. Scappaticci, MD, Providence, RI (Abstract Co-Author) Nothing to Disclose Grayson L. Baird, PhD, Providence, RI (Abstract Co-Author) Nothing to Disclose Anna Ellermeier, MD, Seattle, WA (Abstract Co-Author) Nothing to Disclose PURPOSE Gastric band slippage occurs in up to 30% of gastric band patients. We previously reported the performance of 4 signs (2 old, and 2 new) of slippage on barium swallow exams. This study now evaluates the applicability of these signs to plain radiographs and CT studies performed in the emergency department. METHOD AND MATERIALS We identified 45 gastric band patients who underwent radiography and/or CT in the emergency department from 1/1/2008 – 12/31/2014. Of these patients, 13 were surgically diagnosed with band slippage, while 32 were discharged and returned to standard clinical follow-up without evidence of slippage. Three board-certified radiologists retrospectively reviewed all imaging studies while blinded to patient symptoms and clinical outcomes. The following signs were assessed: (1) abnormally increased phi angle (>58º), (2) inferior displacement of the superolateral gastric band margin from the diaphragm by >2.4 cm, (3) presence of an “O Sign”, and (4) presence of an air-fluid level above the gastric band. Sensitivity, specificity, and interobserver agreement (Cohen’s Kappa statistic) were calculated for each sign. RESULTS For a phi angle >58º, sensitivity and specificity for gastric band slippage were 100% and 81%, respectively, on CT (k=0.93), but 73% and 75% on radiography (k=0.94). For inferior displacement by >2.4 cm, sensitivity and specificity were 89% and 100% on CT (k=0.98), while 100% and 98% on radiography (k=0.92). For presence of an “O sign”, sensitivity and specificity were 13% and 100% on CT (k=0.04), while 30% and 94% on radiography (k=0.64). For presence of an air-fluid level above the gastric band, sensitivity and specificity for slippage were 83% and 99% on CT (k=0.92), while 90% and 100% on radiography (k=0.95). CONCLUSION Both inferior gastric band displacement by >2.4 cm from the diaphragm, and the presence of an air-fluid level above the gastric band, are highly reproducible signs of band slippage in the emergency department, and can be identified on both radiography and CT. CLINICAL RELEVANCE/APPLICATION Signs of gastric band slippage that were recently defined on barium swallow studies can be effectively applied to simple radiography and CT, thus improving efficiency of diagnosis in the emergency department. RC208-03 Epiploic Appendagitis is Associated with Peritoneal Inflammation and Visceral Obesity Monday, Nov. 28 9:10AM - 9:20AM Room: S102AB Participants James P. Nugent, Vancouver, BC (Presenter) Nothing to Disclose Hugue A. Ouellette, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose D. P. O'Leary, PhD, Limerick, Ireland (Abstract Co-Author) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG PURPOSE The location, size and coexisting local inflammatory findings in acute epiploic appendagitis have not been reported outside of isolated case reports. The association between EA and increased body mass index is controversial and disputed in the radiological and surgical literature. Our aim is to investigate if abdominal adipose volume (AAV), visceral adipose area (VAA) and subcutaneous adipose area (SAA) quantified by CT scans is higher in EA patients than matched controls. We also report the location, size and frequency of coexisting local inflammatory findings in a series of patients with acute epiploic appendagitis. METHOD AND MATERIALS Consecutive patients with an imaging diagnosis of EA scanned between January 2009 and June 2014 were selected for inclusion (n = 100). 100 consecutive patients imaged with abdominal CT for non-EA related acute abdominal pain were selected as controls. OsiriX v.5.5.2 (Pixmeo, Geneva, Switzerland) was used to retrospectively quantify abdominal adipose tissue volume and crosssectional area using Hounsfield unit threshold based semi-automated segmentation between -50 HU and -180 HU. The site, size and severity of inflammation of the involved appendage was also recorded. RESULTS EA had a male sex predilection, with 67% of EA versus 41% of acute abdominal cases (p = 0.0002). EA patients had 34% greater AAV, 197% greater VAA, and 135% greater SAA than the control subjects (p < 0.0001). The inflamed appendage was found in the sigmoid colon in 49% of cases, descending colon in 23% and right colon in 19%. Peritoneal thickening was a frequently reported associated sign of inflammation found in 76% of cases. Bowel wall thickening was common (47%) and diverticulosis co-existed incidentally in 28% of cases. CONCLUSION VAA was almost 200% larger in patients with EA as compared with control subjects. Peritoneal thickening was a frequently reported associated sign of inflammation found in 76% of cases. Inflammation of the parietal peritoneum may contribute to the clinical presentation with acute pain. CLINICAL RELEVANCE/APPLICATION The association between EA and increased body mass index is controversial and disputed in radiological and surgical literature. Our study finds that visceral adipose area is almost 200% higher in EA. RC208-04 CT and MRI of Biliary Tract Emergencies Monday, Nov. 28 9:20AM - 9:50AM Room: S102AB Participants Jorge A. Soto, MD, Boston, MA, ([email protected] ) (Presenter) Royalties, Reed Elsevier LEARNING OBJECTIVES 1) Understand the clinical situations where CT or MR are appropriate alternatives to US for the diagnosis of acute conditions affecting the biliary tract. 2) Recognize the CT and MR findings that allow the specific diagnosis of common acute diseases of the biliary tract. 3) Be aware of potential imaging pitfalls that can lead to missed diagnoses or misinterpretations of CT or MR examinations in the setting of suspected acute biliary disease. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator RC208-05 Abdominal Ultrasound for Identifying Cholecystitis after Pain Medication Administration Monday, Nov. 28 9:50AM - 10:00AM Room: S102AB Awards Student Travel Stipend Award Participants Joel P. Thompson, MD, Rochester, NY (Presenter) Nothing to Disclose Jason G. Birnbaum, MD, Rochester, NY (Abstract Co-Author) Nothing to Disclose Timothy M. Baran, PhD, Rochester, NY (Abstract Co-Author) Research Consultant, Zenalux Biomedical Inc Vikram S. Dogra, MD, Rochester, NY (Abstract Co-Author) Editor, Wolters Kluwer nv ; PURPOSE The Murphy sign is reported to have the highest likelihood ratio and specificity for the diagnosis of acute cholecystitis with or without the presence of gallstones. However, many patients receive pain medication prior to ultrasound (US) examination, limiting the ability to elicit a Murphy sign. We sought to identify US signs of cholecystitis in patients after pain medication administration. METHOD AND MATERIALS IRB-approved retrospective review of adult emergency department and inpatients with right upper quadrant pain who received an US within 2 hours of receiving pain medication. Cholescintigraphy (HIDA) performed within 48 hours of the US served as the gold standard to identify patients with and without cholecystitis. Patients post cholecystectomy were excluded. US exams were reviewed for the presence of gallstones, gallbladder distention, wall thickening, sludge, wall hyperemia, and pericholecystic fluid. Gallbladder length and width was measured on a single sagittal image and were used to calculate gallbladder volume.57 patients met inclusion criteria; 6 patients with hepatitis or choledocholithiasis were excluded. US findings compared between 16/51 patients with normal HIDA and 35/51 with positive HIDA. RESULTS Stones in the gallbladder neck were highly associated with cholecystitis (40% vs 6% of controls, p=0.002), particularly when stones were immobile (29% vs 0%, p=0.001). Increased gallbladder distention and lumen width were associated with cholecystitis (67 mL3 vs 34 mL3, p=0.002; width 34 mm vs 27 mm, p=0.014). Lumen width >31 mm had a sensitivity of 60% and specificity of 88% for cholecystitis. Gallbladder sludge was also associated with cholecystitis (54% vs 25%, p=0.045). The presence of gallstones, gallbladder wall thickening, and wall hyperemia were not significantly associated with cholecystitis. No US findings significantly differentiated acute from chronic cholecystitis. CONCLUSION US can reliably identify cholecystitis even when a Murphy's sign cannot be elicited in patients medicated for pain. Immobile gallbladder neck stones, sludge, gallbladder distention, and gallbladder lumen width >31mm are highly associated with cholecystitis. CLINICAL RELEVANCE/APPLICATION US can reliably identify cholecystitis even when a Murphy's sign cannot be elicited in patients medicated for pain, potentially decreasing time to diagnosis and treatment. RC208-06 Seeing is Believing: Visualization of Radiolucent Gallstones on Dual-Energy CT Monday, Nov. 28 10:00AM - 10:10AM Room: S102AB Participants Tim O'Connell, MD, Meng, Vancouver, BC (Presenter) President, Resolve Radiologic Ltd Speake, Siemens AG Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG Faisal Khosa, FFR(RCSI), FRCPC, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Mohammed F. Mohammed, MBBS, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Luck J. Louis, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG PURPOSE Gallstone disease affects 10-15% of the population, and is a frequent cause of presentation to the ER for abdominal pain. Unfortunately, up to 80% of gallstones are radiolucent, making their diagnosis on x-ray or CT very difficult, and requiring an ultrasound or MRI for diagnosis. In this study, we hypothesized that radiolucent calculi not visible on standard CT could be diagnosed using dual-energy CT with post processing using a virtual noncalcium (VNC) technique. METHOD AND MATERIALS 40 dual-energy CT scans in unique patients without evidence of cholelithiasis were obtained, in 20 patients with cholelithiasis and 20 without as proven on a recent ultrasound. CT scans were performed on a dual-tube, dual-energy multidetector CT scanner (either a Siemens Definition Flash or Force). Post processing was performed with Siemens Syngo.Via software using VNC with a threshold set at 0 HU, and these images were reviewed alongside the standard blended-energy greyscale images. Three reviewers (two staff and one fellow), all with abdominal radiology fellowships, reviewed all 40 cases in a blinded and randomized fashion, and scored whether cholelithiasis was present or absent, along with a confidence rating (0-10). RESULTS Of the 20 cases with radiolucent cholelithiasis, 15 were identified correctly by all readers. Of the 20 cases without cholelithiasis, 19 were identified correctly by all readers. Across all readers, diagnostic performance (95% CI) was: Sensitivity 85% (72.9-92.5%), Specificity 98.3% (89.8-99.9%), PPV 98.1%(88.4-99.8%), NPV 86.8% (75.8%-93.4%). Average reader confidence was 9.6/10. If only cases with calculi > 5mm are included, performance improves to: Sensitivity 91.1% (79.6-96.7%), Specificity 98.1% (88.899.9%), PPV 98.1% (88.4-99.9%), NPV 91.3% (80.3-96.8%). CONCLUSION We have demonstrated that dual-energy CT can be used to diagnose cholelithiasis in cases of radiolucent calculi. It is suggested that sensitivity may be better in cases where calculi are larger. Limitations of this study include the small sample size, and a lack of post-surgical correlation for calculus type. Future study will expand the sample size, include ex-vivo calculus evaluation, and also evaluate for cases of choledocholithiasis. CLINICAL RELEVANCE/APPLICATION Diagnosing cholelithiasis at CT will reduce costs of US and MRI usage and will help patients through diagnosis of biliary colic and may improve diagnostic accuracy for cholecystitis. RC208-07 Imaging of Bowel Obstruction Monday, Nov. 28 10:10AM - 10:40AM Room: S102AB Participants Vincent M. Mellnick, MD, Saint Louis, MO (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Utilize CT to identify and characterize bowel obstruction and to correlate these findings with plain film and fluoroscopy. 2) Identify patients for whom MRI would be a reasonable alternative diagnostic imaging choice when radiation dose is a primary concern. 3) Compare the underlying causes and imaging findings of bowel obstruction, including common causes such as adhesions, malignancy, and hernias, emphasizing the differences in epidemiology between small and large bowel obstruction. 4) Assist referring clinicians in identifying the cause and severity of bowel obstruction, including cases complicated by or at risk for ischemia, to guide operative versus nonoperative management. ABSTRACT Bowel obstruction is a common cause for abdominal pain in emergency department patients. A timely diagnosis is critical – when left untreated, bowel obstruction can lead to vascular compromise and potentially necrosis and perforation. CT has become the diagnostic mainstay for evaluating bowel obstruction, and is typically preferred over plain film and fluoroscopy due to its superior performance in identifying an underlying cause as well as patients who have or are at risk for intestinal ischemia. In young patients, particularly those with chronic bowel obstruction and/or who are pregnant, MRI can be a reasonable alternative imaging exam choice, however. Causes of bowel obstruction vary based on anatomic location, but broadly include adhesions, tumors, and hernias. These common causes as well as more rare diagnoses will be discussed in this case-based review. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Vincent M. Mellnick, MD - 2016 Honored Educator RC208-08 New Trends in the Management of Acute Diverticulitis: Predicting Outcomes with MDCT and Clinical Parameters Monday, Nov. 28 10:40AM - 10:50AM Room: S102AB Awards Student Travel Stipend Award Participants David D. Bates, MD, Boston, MA (Presenter) Nothing to Disclose Marina C. Bernal Fernandez, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Cecilia Ponchiardi, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Michael von Plato, Boston, MA (Abstract Co-Author) Nothing to Disclose Joshua Teich, Boston, MA (Abstract Co-Author) Nothing to Disclose Chaitan Narsule, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Avneesh Gupta, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE To determine whether MDCT imaging features and clinical findings can predict outcomes in patients with acute diverticulitis in the Emergency Department (ED). METHOD AND MATERIALS This retrospective study was IRB approved; informed consent was waived. All adult patients (>18 years old) diagnosed with acute diverticulitis in the ED via contrast-enhanced abdominopelvic MDCT from 1/1/2015-12/31/2015 were included. 169 patients met inclusion criteria (males n=69, female n=100, mean age 54.7 years, range 23-90 years). The CT studies were blind reviewed by an abdominal radiologist for the presence of bowel wall thickening, inflamed diverticulum, pericolonic inflammation, pericolonic fluid collection, free fluid, free air or fistula. A Hinchey classification was also determined. Clinical data was acquired via medical chart review. Clinical parameters and CT imaging findings were compared with the clinical outcomes. Statistical analysis was performed using Fisher's exact test and Student's t-test. RESULTS Statistically significant imaging features on MDCT for patients requiring surgical management at any point during the study period included the presence of a pericolonic fluid collection (p = 0.0011), a Hinchey classification of 1b or greater (p = 0.0002) and the presence of a colonic fistula (p = 0.0007). There was no significant difference for the presence of bowel wall thickening, an inflamed diverticulum, pericolonic inflammation, free fluid, or free air. No laboratory values or vital sign parameters were significantly different. CONCLUSION Imaging features demonstrating a significant association with the need for surgery when compared with diverticulitis patients who were successfully managed non-operatively include the presence of a pericolonic collection, a colonic fistula, or a Hinchey classification of 1b or higher. In addition, increased hospital length of stay was associated with the need for surgical management. CLINICAL RELEVANCE/APPLICATION In light of a trend in surgical management away from colonic resection, CT imaging and clinical parameters may predict which patients will require operative management in acute diverticulitis. RC208-09 Inter-Reader Agreement of CT Features of Acute Mesenteric Ischemia Monday, Nov. 28 10:50AM - 11:00AM Room: S102AB Participants Pauline Copin, MD, Clichy, France (Presenter) Nothing to Disclose Maxime Ronot, MD, Clichy, France (Abstract Co-Author) Nothing to Disclose Matthieu Lagadec, MD, Clichy, France (Abstract Co-Author) Nothing to Disclose Julie Benzimra, Paris, France (Abstract Co-Author) Nothing to Disclose Anne Kerbaol, Paris, France (Abstract Co-Author) Nothing to Disclose Magaly Zappa, MD, Clichy, France (Abstract Co-Author) Nothing to Disclose Valerie Vilgrain, MD, Clichy, France (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the inter-reader agreement of CT features of acute mesenteric ischemia (AMI) METHOD AND MATERIALS This study was approved by the IRB and informed consents were waived. Between 2006 and 2014, all patients admitted in our institution with the diagnosis of acute mesenteric ischemia were included. CT scans were retrospectively reviewed by two abdominal radiologists. Inter-observer agreement of imaging features of vascular insufficiency, bowel ischemia, and complication was assessed with the percentage of agreement and the kappa statistics. RESULTS The final population included 109 patients (57 men, 52%, mean age 50 years [17-83]), including 42% initially managed in our institution. AMI was occlusive in 102 patients (94%), including 72 (66%), 30 (28%), and 10 (9%) patients with an arterial, venous, and combined cause of AMI. respectively. The median time delay between symptoms onset and CT scan acquisition was 1 day, and 71% were performed during the first 48-hours. CT protocol included unenhanced images in 77 (71%) patients, arterial phase images in 73 (67%) patients, and oral contrast media ingestion in 11 (10%) patients. The image quality was rated as excellent for the majority of the patients (65% for reader 1 and 75% for reader 2). Inter-observer agreement was highly variable (k=0.25-0.98). Decreased/absent bowel wall enhancement showed moderate inter-observer agreement (k=0.52), but rose to excellent (k=0.82) in the 47 patients (43%) with both unenhanced and arterial phase images, no oral contrast medium, and excellent image quality ("optimal" CT protocol). It was also improved in patients with serum lactate level >2mmol/L and when CT scan was performed during the first 24-hours after the symptoms onset. Inter-observer agreement for thickened wall (k = 0.56 vs. k = 0.61), and bowel loop dilatation (k = 0.63 vs. k = 0.65) were not improved in patients with an optimal CT protocol, but that for the small bowel feces sign was significantly higher (k = 0.65 vs. k = 0.44). CONCLUSION Most imaging features of AMI show moderate to substantial inter-reader agreement. An optimal CT protocol acquisition leads to an improved inter-observer agreement of imaging features of AMI, especially for the decreased/absent bowel wall enhancement. CLINICAL RELEVANCE/APPLICATION An optimal CT scan protocol acquisition should be performed to improved inter-observer agreement of imaging features of AMI, and better identify patients with bowel necrosis. RC208-10 MRI of Acute Right Lower Quadrant Pain Monday, Nov. 28 11:00AM - 11:30AM Room: S102AB Participants Jennifer W. Uyeda, MD, Boston, MA, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) To review the current utilization of MR imaging in acute right lower quadrant pain in the emergency setting. 2) To describe potential pitfalls in interpretation of MR in acute right lower quadrant pain. 3) To illustrate cases of various etiologies for acute right lower quadrant pain and their imaging manifestations on MR imaging. ABSTRACT RC208-11 Magnetic Resonance Imaging of Pregnant Appendicitis: Sensitivity, Specificity and Inter-reader Reliability Monday, Nov. 28 11:30AM - 11:40AM Room: S102AB Participants Richard Tsai, MD, Saint Louis, MO (Presenter) Nothing to Disclose Joseph W. Owen, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Vincent M. Mellnick, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Constantine A. Raptis, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose Kathryn J. Fowler, MD, Chesterfield, MO (Abstract Co-Author) Nothing to Disclose PURPOSE The literature on MR imaging of suspected appendicitis in pregnancy demonstrates a low negative predictive value which may be the result of a low incidence of disease. Despite this low reported negative predictive value, the MR diagnosis of appendicitis is not binary, with findings such as free fluid and increased appendiceal diameter alone lacking specificity and frequently producing an indeterminate result. A retrospective review was performed of all cases of suspected appendicitis in pregnancy imaged with MR to assess the rate of acute appendicitis after an indeterminate interpretation. METHOD AND MATERIALS A retrospective chart review of MR interpretations for pregnant patients with suspected appendicitis presenting to the emergency room was performed from 1/1/2003 to 4/1/2015. MR interpretations that were not read as unequivocally positive or negative were categorized as "indeterminate" for appendicitis. Patient outcomes were categorized as "acute appendicitis," "no acute appendicitis," and "other appendiceal pathology”. Reference standard was surgical pathology and clinical outcomes. RESULTS There were 240 cases of abdominal MR performed in pregnant women for suspected appendicitis at our institution with 13 cases of acute appendicitis. 206 cases were interpreted as negative with 1 false negative. 19 cases were interpreted as positive, 12 had acute appendicitis, 3 had non acute appendiceal pathology, 3 had a normal appendix, and 1 patient was observed and released without antibiotics (7 false positives). 15 cases were interpreted as indeterminate (e.g. upper limits of normal appendix with adjacent free fluid or dilated appendix but no free fluid or stranding), 4 patients went to surgery and 8 patients were admitted for observation, no patient had acute appendicitis and 1 patient who was observed was a new presentation of Crohn disease which was included in the differential. CONCLUSION MR imaging of appendicitis has a low negative predictive value, likely due to the low prevalence, and a high rate of indeterminate interpretations. Equivocal findings of appendicitis including adjacent free fluid and “upper limits of normal appendix” should not be managed surgically, but may warrant admission for observation. CLINICAL RELEVANCE/APPLICATION MR imaging of pregnant appendicitis can help triage patients to those that may be managed conservatively, surgically, or may provide an alternative diagnosis. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Vincent M. Mellnick, MD - 2016 Honored Educator RC208-12 Anatomic Reasons for Failure to Visualize the Appendix with Graded Compression Sonography: Insights from Concurrent CT Monday, Nov. 28 11:40AM - 11:50AM Room: S102AB Awards Trainee Research Prize - Resident Participants Wilson Lin, MD, Redwood City, CA (Presenter) Nothing to Disclose Angela Trinh, MD, Palo Alto, CA (Abstract Co-Author) Nothing to Disclose Eric W. Olcott, MD, Palo Alto, CA (Abstract Co-Author) Nothing to Disclose R. Brooke Jeffrey Jr, MD, Stanford, CA (Abstract Co-Author) Nothing to Disclose PURPOSE To identify anatomic reasons from CT for non-visualization of the appendix on graded compression sonography (GCS) METHOD AND MATERIALS A searchable database retrospectively yielded 197 consecutive patients with suspected appendicitis, enrolled over 22 months, who met inclusion criteria including: 1) appendiceal GCS was the initial imaging examination, performed in typical fashion at 8-15 MHz, 2) appendix was not visualized on GCS, and 3) appendix was visualized on CT performed within 48 hours after sonography. The following were evaluated on post-sonography CT, defining appendix position as that of the appendiceal tip: depth from the skin surface, position above or below the iliac crest, and axial location in one of four quadrants centered on the ileocecal valve, designated anteromedial (AMQ), posteromedial (PMQ), posterolateral (PLQ), and anterolateral (ALQ). Statistical evaluations with Stata 14.1 software employed the two-sided multinomial test to evaluate appendiceal distribution among quadrants collectively, and the exact binomial test to evaluate appendiceal distribution in quadrants specifically and to determine 95% confidence intervals (CI). RESULTS The depth of the appendix from the skin surface ranged 7 to 163 mm (mean 78.9 mm, 95% CI 75.1 - 82.7 mm) overall, and 94 to 163 mm in the deepest quartile of appendices. Of the 197 patients, 39 (19.8%, 95% CI 14.4-26.1%) had appendices lying above the iliac crest. Frequencies of the appendix found in the ALQ, PMQ, PLQ, and AMQ were 18 (9.1%), 123 (62.4%), 43 (21.8%), and 13 (6.6%), respectively, with highly significant non-uniformity among the quadrants collectively (P < 0.0001) favoring the PMQ specifically (P < 0.0001). CONCLUSION Appendices not visualized on sonography are significantly likely to lie in the PMQ, at a depth of 94-163 mm in 25% of patients and above the iliac crest in 19.8% of patients. Because these regions are not typically scanned in GCS, additional scanning for the nonvisualized appendix is indicated specifically through the PMQ, above the iliac crest, and with atypically low frequency (e.g., 6 MHz or less) sufficient to reach 9-16 cm in depth. CLINICAL RELEVANCE/APPLICATION When the appendix is not initially visualized on sonography, further specific scanning should be performed posteromedially to the ileocecal valve as well as above the iliac crest, and with sufficiently low frequency (i.e. 6 MHz or less) to interrogate 9-16 cm from the skin surface. RC208-13 Are Spectral Doppler Waveforms Useful to Diagnose Acute Appendicitis? Monday, Nov. 28 11:50AM - 12:00PM Room: S102AB Participants Lewis Shin, MD, Stanford, CA (Presenter) Nothing to Disclose Eric W. Olcott, MD, Palo Alto, CA (Abstract Co-Author) Nothing to Disclose Gerald Berry, MD, Stanford, CA (Abstract Co-Author) Nothing to Disclose R. Brooke Jeffrey Jr, MD, Stanford, CA (Abstract Co-Author) Nothing to Disclose PURPOSE To test the hypothesis that appendiceal spectral Doppler waveforms distinguish patients with and without acute appendicitis. METHOD AND MATERIALS With IRB approval and HIPAA compliance, sonograms performed for suspected appendicitis in 337 consecutive patients over 5 months were retrospectively blindly reviewed. Of the 155 (46%) patients in whom the appendix was visualized, spectral Doppler tracings with peak systolic velocities (PSV) and resistive indices (RI) were successfully acquired in 95 (61%). These 95 patients were categorized as appendicitis-positive [A(+)] by histopathologic examination after appendectomy or by CT confirmation of appendicitis, or as appendicitis-negative [A(-)] when 6-week post-sonography clinical chart review demonstrated no further evidence of appendicitis. Data were compared and confidence intervals (CI) obtained with Stata 14.1 software utilizing the 2-tailed T test for means and the exact binomial test for proportions. RESULTS The 95 patients with spectral Doppler tracings included 74 children (age <19 years) and 21 adults (ages 1-56 years, mean 13.3 years), with 54 males and 41 females, of whom 56 were A(-) and 39 were A(+).The mean PSV for A(-) and A(+) subjects were 7.1cm/s (95% CI 6.4-7.8 cm/s) and 19.2cm/s (95% CI 7.1-21.2 cm/s), respectively (P<0.0001). The mean RI for A(-) and A(+) subjects were 0.49 (95% CI 0.47-0.52) and 0.68 (95% CI 0.64-0.73), respectively (P<0.0001).Utilizing PSV >10 cm/s as abnormal, sensitivity and specificity for appendicitis were 87.2% (95% CI 72.6-95.7%) and 94.6% (95% CI 85.1-98.9%), respectively. Utilizing RI >0.60 as abnormal, sensitivity and specificity were 69.2% (95% CI 52.4-83.0%) and 89.3% (95% CI 78.1-96.0%), respectively. Utilizing both PSV >10cm/s and RI >0.60 as abnormal, sensitivity and specificity were 64.1% (95% CI 47.2-78.8%) and 96.4% (95% CI 87.7-99.6%), respectively. CONCLUSION Patients with appendicitis exhibit significantly higher PSV and RI than patients without appendicitis, and are distinguishable with high specificity utilizing PSV >10cm/s and RI >0.60 as diagnostic criteria. CLINICAL RELEVANCE/APPLICATION Spectral Doppler interrogation appears potentially useful for distinguishing patients with appendicitis from those without appendicitis, providing a high level of specificity utilizing straightforward criteria based on PSV and RI. ERS-MOA Emergency Radiology Monday Poster Discussions Monday, Nov. 28 12:15PM - 12:45PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Ferco H. Berger, MD, Toronto, ON (Moderator) Nothing to Disclose Sub-Events ER208-SDMOA1 Multi Detector CT Angiography (CTA): Influence of Its Findings in Therapeutic Decision-making in Patients with Acute Lower Gastrointestinal Bleeding in the Emergency Service Station #1 Participants Alfonso Martin Diaz, BMedSc, San Sebastian De Los Reyes, Spain (Presenter) Nothing to Disclose Lucia Fernandez Rodriguez, BMBS, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Lorena F. Rodriguez-Gijon, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Milagros Marti De Gracia, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Alberto Borobia, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Aurea Diez Tascon, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Jose Maria Artigas, Zaragoza, Spain (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the influence of multidetector CTA findings in therapeutic management of patients with ALIB. METHOD AND MATERIALS Retrospective observational study that includes patients with ALIB signs in the Emergency Service of a tertiary Hospital, from October 2009 to October 2013. Adults with rectal bleeding/ hematochezia (anorectal source excluded) or patients with melena and negative upper endoscopy are included. A triphasic CT examination was performed.Studied variables: demographics, nature, source and etiology of bleeding, and therapeutic procedure.Descriptive results are expressed as absolute frequencies and percentages. Univariate analysis (chi-square and student-T, or their non parametric equivalent) was performed to evaluate differences in variables between patients with and without active bleeding. Statistic software IBM SPSS Statistic v.20 was used.This study has been approved by Etical Comitee of Clinical Investigation from La Paz Universitary Hospital. RESULTS In this period of time 173 CTA were performed in patients with ALIB signs. 30 of them were excluded because of insufficient information. Final analysis was made over 143 patients (68 women; 75 men), mean age 72,6 years (SD 19,6). CTA indicated bleeding lesion in 121 patients (84,6%) and showed active bleeding in 48 (33,6%), 43 arterial and 5 venous source.32 patients (66,7%) from the group with active bleeding required immediate therapeutic procedure (8 angiography, 17 endoscopy and 7 surgery) versus 5,3% in patients without demonstrated active bleeding(p<0,001). CONCLUSION Presence of active bleeding on CTA is an independent factor in the therapeutic decision-making. CLINICAL RELEVANCE/APPLICATION CT angiography has become the image modality of chice for the management of patients with acute lower gastrointestinal bleeding in Emergency Service. ER209-SDMOA2 Variability in Emergency Department Utilization of Lumbar spine MRI for Evaluation of Low Back Pain: How Much Inappropriate Imaging is Being Done, and for What Reasons Station #2 Participants Travis Smith, BS,MS, Hershey, PA (Presenter) Nothing to Disclose Michael A. Bruno, MD, Hershey, PA (Abstract Co-Author) Nothing to Disclose Timothy J. Mosher, MD, Hershey, PA (Abstract Co-Author) Research Consultant, Medical Metrics, Inc Stockholder, Johnson & Johnson PURPOSE Managing the appropriate use of advanced medical imaging is both an essential element and a significant challenge for radiologists seeking to optimizing value in imaging. The high value for patients of appropriately utilized imaging services is readily apparent; however no value is added when imaging is chosen inappropriately. Determining appropriate uses of Magnetic Resonance Imaging (MRI) for evaluation of patients with low back pain is under review by several agencies, based on evidence of comparative effectiveness and as an opportunity to increase value of clinical care. The National Quality Forum (NQF) currently has two quality measures under consideration addressing imaging of patients with low back pain; NQF measure number 0052 "Use of Imaging Studies for Low Back Pain”, and NQF measure number 0514 MRI Lumbar Spine for Low Back Pain. METHOD AND MATERIALS A total of 233 MRI examinations of the lumbar spine were performed on patients seen in our ED in CY 2014, of which 63 were requested for evaluation of low back pain and another 76 were listed as “other.” We scored these studies via a detailed manual audit of the EMR in order to assess the level of appropriate utilization based on the National Quality Forum (QPS) Measure 0514. Secondarily, we have attempted to identify factors that drive inappropriate ED utilization of lumbar spine MRI for patients with low back pain, testing the hypotheses that (1) there is inappropriate use of the ED specifically for the purpose of circumventing outpatient MRI utilization controls and (2) that there is significant self-referral of patients to ED in order to expedite their care, i.e., to “jump the queue.” RESULTS Of the 233 examinations, 41 (17.6%) were considered to be inappropriate based on our standard. A significant fraction of these appear to represent misuse of the Emergency Department either to circumvent outpatient utilization controls or to expedite a scheduled outpatient study . CONCLUSION While most utilization of MRI in the Emergency Setting was appropriate, a significant fraction of patients appear to be misusing the ED to circumvent utilization controls or wait times for routine outpatient care. CLINICAL RELEVANCE/APPLICATION This study is clinically relevant in that it evaluates the use of evidence-based medicine vs. other factors in the utilization of advanced medical imaging in the ED setting. ER210-SDMOA3 Very Affordable Immersion Pump for Post Mortem CT Angiography in Forensic Pathology: First 10 Cases. The Results Were Comparable, In That No Notable Differences Remained Station #3 Participants Wolf Schweitzer, MD, Zuerich, Switzerland (Presenter) Nothing to Disclose Patricia M. Flach, MD, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Michael J. Thali, MD, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Dominic Gascho, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Stamatios Stamou, MD, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose PURPOSE About ten years after the usage of roller pumps for post mortem CT angiography was introduced into forensic pathology, it remains an open question why that relatively expensive pump mechanism (costing around 1000 USD for a used old heart lung machine to 80 000 USD for dedicated top of the line post mortem equipment) is actually necessary for post mortem CT angiography (PMCTA).Roller pumps make sense for non-Newtonian fluids like blood, where also mechanical hemolysis is a factor. In PMCTA, however watery or oily liquid is pumped into the vascular system of a body.After we established in a feasibility study that a simple immersion pump (priced around 15-20 USD) can be calibrated to obtain a linear voltage - flowrate relationship for the contrast agent solution used, and that vascular filling compared to a roller pump is basically the same, we present the results of the first ten cases in this talk. METHOD AND MATERIALS Cantonal ethics review board waived responsibility (retrospective anonymized data usage).10 cases from forensic pathology caseload were selected where PMCT angiography (PMCTA) was seen as relevant to the case. 10 control cases examined with a conventional heart lung machine roller pump were used as comparison. Both arterial and venous sides were filled from a femoral access.Immersion pump: a Barwig model 0444 pump (max. 10L/min) was used (required PMCTA flow rate 0,2 - 0,8L/min).Roller pump: Stoeckert Shiley heart lung machine (max. 10L/min) was employed.PMCT / PMCTA: Dual source / energy CT scanner (Somatom Flash Definition, Siemens, Germany) was used (100 kVp tube voltage, automatic dose modulation). RESULTS Vascular filling was compared related to large vessels, coronary arteries, neck and head arteries, extremity arteries and on the same level, veins. Figure (IP: immersion pump: HLM: heart lung machine). CONCLUSION With a very low fraction of the cost, forensic pathology may be supplemented with high quality PMCTA when using a cheap immersion pump. CLINICAL RELEVANCE/APPLICATION To be able to perform a post mortem CT angiography with very affordable equipment means that a parametrized method can be validated and employed in far more institutes than when very expensive equipment is used. ER211-SDMOA4 Absent Secondary Signs of Appendicitis When the Appendix is Not Visualized Station #4 Participants Vivek Patel, MD, New Haven, CT (Abstract Co-Author) Nothing to Disclose Aditi Vyas, MD, Norwalk, CT (Abstract Co-Author) Nothing to Disclose Saad Hussain, MD, New Haven, CT (Presenter) Nothing to Disclose Mahan Mathur, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Mike Spektor, MD, New Haven, CT (Abstract Co-Author) Nothing to Disclose PURPOSE The purpose of this study is to determine the negative predictive value (NPV) of the sonographic secondary signs of appendicitis when the appendix is not visualized. The secondary signs of appendicitis seen on ultrasound (US) include free fluid, hyperemia, lymphadenopathy, and phlegmon formation. METHOD AND MATERIALS A retrospective review was completed looking for ultrasound images and reports that did not visualize the appendix in its entirety and also specifically stated that no secondary signs of appendicitis were visualized. The review spans 2013-2015. 130 studies were found meeting the inclusion criteria. RESULTS Of the 130 total studies, 95 did not have imaging follow up or surgery for appendicitis. Either the ultrasound revealed an alternate diagnosis (example: mesenteric adenitis) or the patient was discharged with an alternate clinical diagnosis (example: constipation). 35 studies had follow up imaging with CT (31), MRI (2) or US (2). Of the 31 follow up CTs, 4 did not visualize the appendix (and the patients were discharged) and the remaining 27 revealed normal appendices. The 2 MRI examinations showed normal appendices and the patients were discharged. One repeat ultrasound was negative and the patient was discharged. The other repeat ultrasound was positive and the patient was taken to surgery and had pathology proven appendicitis.The negative predictive value for absent secondary signs of appendicitis when the appendix is not visualized is 97%. CT, MRI, and repeat US that visualized a negative appendix were considered true negatives. CONCLUSION When the appendix is not visualized clinicians are often left to make a decision on whether or not to subject the patient (often pediatric) to ionizing radiation (CT), a lengthy MRI or a repeat US. It is important that radiologists and technologists look for the secondary signs of appendicitis when the appendix is not visualized. The radiologist should specifically mention the lack of secondary signs when appropriate. Based on the findings of this study, such a statement carries a high NPV. Armed with such information, the clinicians will be better suited in making the difficult decision in regards to further imaging or intervention. CLINICAL RELEVANCE/APPLICATION Secondary signs of appendicitis carry a high negative predictive value and should be evaluated for when the appendix is not visualized on ultrasound. ER212-SDMOA5 Epiploic Appendagitis is Associated with Peritoneal Inflammation and Visceral Obesity Station #5 Participants James P. Nugent, Vancouver, BC (Presenter) Nothing to Disclose Hugue A. Ouellette, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose D. P. O'Leary, PhD, Limerick, Ireland (Abstract Co-Author) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG PURPOSE The location, size and coexisting local inflammatory findings in acute epiploic appendagitis have not been reported outside of isolated case reports. The association between EA and increased body mass index is controversial and disputed in the radiological and surgical literature. Our aim is to investigate if abdominal adipose volume (AAV), visceral adipose area (VAA) and subcutaneous adipose area (SAA) quantified by CT scans is higher in EA patients than matched controls. We also report the location, size and frequency of coexisting local inflammatory findings in a series of patients with acute epiploic appendagitis. METHOD AND MATERIALS Consecutive patients with an imaging diagnosis of EA scanned between January 2009 and June 2014 were selected for inclusion (n = 100). 100 consecutive patients imaged with abdominal CT for non-EA related acute abdominal pain were selected as controls. OsiriX v.5.5.2 (Pixmeo, Geneva, Switzerland) was used to retrospectively quantify abdominal adipose tissue volume and crosssectional area using Hounsfield unit threshold based semi-automated segmentation between -50 HU and -180 HU. The site, size and severity of inflammation of the involved appendage was also recorded. RESULTS EA had a male sex predilection, with 67% of EA versus 41% of acute abdominal cases (p = 0.0002). EA patients had 34% greater AAV, 197% greater VAA, and 135% greater SAA than the control subjects (p < 0.0001). The inflamed appendage was found in the sigmoid colon in 49% of cases, descending colon in 23% and right colon in 19%. Peritoneal thickening was a frequently reported associated sign of inflammation found in 76% of cases. Bowel wall thickening was common (47%) and diverticulosis co-existed incidentally in 28% of cases. CONCLUSION VAA was almost 200% larger in patients with EA as compared with control subjects. Peritoneal thickening was a frequently reported associated sign of inflammation found in 76% of cases. Inflammation of the parietal peritoneum may contribute to the clinical presentation with acute pain. CLINICAL RELEVANCE/APPLICATION The association between EA and increased body mass index is controversial and disputed in radiological and surgical literature. Our study finds that visceral adipose area is almost 200% higher in EA. ER166-EDMOA6 MDCT of Midfacial Fractures: Classification Systems, Principles of Reduction, and Common Complications Station #6 Awards Certificate of Merit Identified for RadioGraphics Participants David Dreizin, MD, Baltimore, MD (Presenter) Nothing to Disclose Silviu Diaconu, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Uttam Bodanapally, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Arthur Nam, MD, MS, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Felipe Munera, MD, Miami, FL (Abstract Co-Author) Nothing to Disclose TEACHING POINTS After completing this exhibit, viewers will be able to… 1. Understand the dependent nature of midfacial fractures and importance of sagittal buttresses for restoring facial projection.2. Explain why Le Fort fracture level is the most important aspect of these fractures to plastic and reconstructive surgeons. 3. Describe common fracture classifications of the palatoalveolar, naso-orbito-ethmoid, zygomatic (malar), and orbital regions, and how they influence operative decision making.4. Deduce the surgeon’s reasoning for operative approach, mandibulo-maxillary fixation, choice of plate-fixation points, use of bone grafting, trans-nasal canthal wiring and other techniques based on postoperative MDCT. TABLE OF CONTENTS/OUTLINE Beyond buttresses: “stability” in midface fractures. Know your sutures. Palatoalveolar fractures: classifactions Le Fort fractures: Le Fort I/II/III - review/limitations. Level is key. coexisting ZMC and NOE fractures. Orbital fractures: herniated fat, orbital volume, and enophthalmos; Blow in and blow out; Defect size mattersNOE fractures: NOE I/II/III; Know your anatomy; post-op findingsZMC fractures: Grading ZMCs- the zygomaticosphenoid suture; How many plates are enough? A note on zygomatic archLooking to the future: 3D printing and intra-operative CBCT Lunch & Learn: Transitioning to DR, Clinical and Financial Benefits Beyond Preventing Reimbursement Penalties: Supported by Fujifilm (invite-only) Monday, Nov. 28 12:30PM - 1:30PM Room: S403B Participants PARTICIPANTS Jerry Thomas, MS, FAAPM, DABR, CHP, DABSNM Wichita, KS William Tobin BS, Tyler, TX PROGRAM INFORMATION This course does not offer CME credit. ERS-MOB Emergency Radiology Monday Poster Discussions Monday, Nov. 28 12:45PM - 1:15PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Ferco H. Berger, MD, Toronto, ON (Moderator) Nothing to Disclose Sub-Events ER213-SDMOB1 Clinical Parameters Predict Subsequent Traumatic Hepatic and Splenic Injury Identified on Computed Tomography Station #1 Participants Michael J. Hsu, MD, Boston, MA (Presenter) Nothing to Disclose Michael Wasserman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer Xiao, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Venkata Satyam, Boston, MA (Abstract Co-Author) Nothing to Disclose Tina Shiang, Boston, MA (Abstract Co-Author) Nothing to Disclose Deepan Paul, Boston, MA (Abstract Co-Author) Nothing to Disclose Ahmed Y. El-Araby, MD , West Warwick, RI (Abstract Co-Author) Nothing to Disclose Vaeman Chintamaneni, Boston, MA (Abstract Co-Author) Nothing to Disclose Robert Burns, Boston, MA (Abstract Co-Author) Nothing to Disclose Arthur Baghdanian, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jorge A. Soto, MD, Boston, MA (Abstract Co-Author) Royalties, Reed Elsevier Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE The purpose of this study was to examine commonly collected clinical parameters in the trauma patient, and to determine which parameters predict subsequent traumatic injury to the liver and spleen as identified on computed tomography (CT). METHOD AND MATERIALS This HIPAA-compliant, retrospective study performed at our urban academic teaching hospital was approved by the Institutional Review Board (IRB); informed consent was waived.All adult patients presenting over a two-year period with hepatic or splenic trauma as evidenced by CT imaging were enrolled (n=49). A control group of 50 patients presenting with trauma but with negative CT findings was included for comparison. Admission clinical parameters such as heart rate (HR) and blood pressure (BP) as well the admission lab values hematocrit (Hct), lactate, blood urea nitrogen (BUN) and creatinine (Cr) were collected for each patient. Subsequently, the differences in these clinical parameters between the two groups were analyzed using a t-test with pvalue of <0.05 considered statistically significant. RESULTS The mean Hct was 39.5 for females and 43.4 for males in the control group and 35.0 for females and 40.6 for males in the hepatosplenic injury group. Hematocrit was significantly lower in the hepatosplenic injury group (p = 0.003 for females and p = 0.006 for males).Mean lactate was 1.72 and 3.28 for the control and hepatosplenic injury groups, respectively. While lactate was abnormally elevated for both groups, the hepatosplenic injury group demonstrated a significantly greater degree of lactate elevation (p = 0.0001).Heart rate and blood pressure were similar between the two groups with no statistically significant differences identified.Additional laboratory values which were analyzed, including BUN and Cr, were not predictive of hepatosplenic injury as no statistically significant differences were identified. CONCLUSION The admission clinical parameters of HCT and lactate are predictive of traumatic hepatic and splenic injury identified on CT imaging. Awareness of the potential utility of these clinical parameters may assist in triage and CT protocol considerations during the initial patient evaluation in the trauma setting. CLINICAL RELEVANCE/APPLICATION Identifying clinical parameters that predict hepatosplenic injury on CT alerts physicians to possible hepatosplenic injury, which may help CT protocol decision-making and support earlier CT imaging. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator ER214-SDMOB2 Evaluating the Predictive Value of Risk Factors for Retroperitoneal Hemorrhage Station #2 Participants Ahmed Fadl, MD, Mineola, NY (Presenter) Nothing to Disclose Rishi Chopra, Mineola, NY (Abstract Co-Author) Nothing to Disclose Abieyuwa Eweka, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Amanjit S. Baadh, MD, New York, NY (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Jason C. Hoffmann, MD, Mineola, NY (Abstract Co-Author) Consultant, Merit Medical Systems, Inc; Speakers Bureau, Merit Medical Systems, Inc Sameer Mittal, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose PURPOSE Retroperitoneal bleed (RPB) is an uncommon and potentially life threatening condition, often requiring a high index of suspicion to diagnose correctly. Concern for RPB is often raised given physical examination findings and pertinent laboratory values. Noncontrast computed tomography (CT) has proven to be a fast and accurate means to emergently assess these patients. We retrospectively evaluated specific risk factors in a series of patients and determined their predictive values in developing RPB when correlating with CT findings, with the goal of determining which factors are important to consider when determining if emergent imaging is warranted. METHOD AND MATERIALS A single institutional retrospective analysis of 1,000 consecutive patients who underwent a non-contrast CT of the abdomen and pelvis to evaluate specifically for RPB was conducted. Patients were selected from a database of CT imaging requests (June 2008June 2011). Values including vital signs, recent invasive procedures, coagulation panel, hematologic status, and anticoagulant use were documented. Corresponding CT imaging at the time of evaluation was analyzed by two board-certified radiologists for the presence of a retropertioneal bleed. Findings were subsequently compared between the RPB and non-RPB cohorts. RESULTS Of the 1,000 patients meeting inclusion criteria, 29 were found to have CT confirmed RPB. A randomly selected equal size cohort with CT confirmed studies negative for RPB was gathered for comparison. Analysis demonstrated that the CT confirmed RPB patients had a statistically significant low mean arterial pressure (MAP), with average MAP 76 mmHg versus 86 mmHg in control group (p=0.0008). Recent invasive procedure was also found to have significance, with 24 of 29 in the RPB group having recent invasive procedures, compared to 3 of 29 in the control group (p=0.0068). Drop in hemoglobin/hematocrit, coagulation panel, and anticoagulant use were not found to have statistical significance. CONCLUSION Although uncommon, RPB warrants a high index of suspicion and prompt evaluation due to associated morbidity and mortality. Low mean arterial pressure and recent invasive procedure have predictive value in determining which patients should be emergently imaged. CLINICAL RELEVANCE/APPLICATION Low mean arterial pressure and history of a recent invasive procedure have predictive value in deciding whether emergent imaging is appropriate to evaluate for RPB. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator ER215-SDMOB3 The Combination of SWI and DTI in Diagnosing Different Severity's Traumatic Brain Injury Station #3 Participants Chengru Song, Zhengzhou, China (Presenter) Nothing to Disclose Jingliang Cheng, MD,PhD, Zhengzhou, China (Abstract Co-Author) Nothing to Disclose Yong Zhang, DO, Zhengzhou, China (Abstract Co-Author) Nothing to Disclose PURPOSE To explore the diagnostic value of SWI and DTI on different severity's traumatic brain injury(TBI). METHOD AND MATERIALS Totally 60 TBI patients (including 20 mild TBI patients, 20 moderate TBI patients and 20 severe TBI patients) and 20 health volunteer underwent SWI, DTI and conventional MRI examination. The numbers of involving regions, numbers and areas of hemorrhagic lesions detected by SWI, and FA values of 37 brain regions (including knee, body, splenium of corpus callosum, cingulate bundle, et al.) were compared between each two groups. The correlation analysis between GCS scores and the number of involving regions, number of hemorrhagic lesions, areas of hemorrhagic lesions detected by SWI, and FA values of each region were performed. RESULTS The differences of involving regions' number, lesions' number, lesion's areas detected by SWI between each two groups were statistically significant (P<0.05). Severe TBI group got the maximum number of involving regions, lesions, and the largest areas. Followed by moderate group and mild group. Among the 37 regions, totally 30 regions differ in FA values between the four groups (P<0.05). And among these 30 regions, 18 regions' FA values, for example corpus callosum region, gradually reduce as the severity of TBI aggravate. The GCS scores are highly negatively correlated with the number of involving regions, number of lesions, areas of lesions detected by SWI, but are positively correlated with 30 regions' FA values. The descending order of relevance is hemorrhagic lesions’ areas(r=-0.932), lesions' number(r=-0.911), involving regions' number(r=-0.900), FA values of right cingulum(r=0.872), right anterior limb of internal capsule(r=0.801), left cingulum (r=0.787), the splenium of corpus callosum(r=0.775), the body of corpus callosum (r=0.765), et al. CONCLUSION The clinical applications of SWI and DTI is valuable in diagnosing different severity's TBI. CLINICAL RELEVANCE/APPLICATION SWI and DTI can be applied in the diagnosis of different severity's TBI. ER216-SDMOB4 Reducing the Use of CT Angiography in Low Risk Patients with Suspected Pulmonary Embolism via Implementation of Decision Points in the Emergency Room Setting Station #4 Awards Student Travel Stipend Award Participants Andrew J. Cantos, MD, East Meadow, NY (Presenter) Nothing to Disclose Michael Drabkin, MD, East Meadow, NY (Abstract Co-Author) Nothing to Disclose Harold Hunt, MD, East Meadow, NY (Abstract Co-Author) Nothing to Disclose Alexander Martynov, MD, East Meadow, NY (Abstract Co-Author) Nothing to Disclose Eli Q. Harris, BA, East Meadow, NY (Abstract Co-Author) Nothing to Disclose Victor J. Scarmato, MD, East Meadow, NY (Abstract Co-Author) Nothing to Disclose PURPOSE To reduce waste in spending, radiation exposure to patients and Radiology Department resources by using accepted criteria and obtaining D-dimers in order to minimize ordering of CT angiography (CTA) for exclusion of pulmonary embolus. METHOD AND MATERIALS Following IRB approval, we reviewed 697 consecutive patients who had CTA to exclude PE over an 18-month period. We set out to determine whether the appropriate decision points were being used. We systematically documented patients’ presenting symptoms, demographic information, comorbidities and the results of their hospital workup. Risk categories were assigned, including consideration of the Wells Criteria. RESULTS Of the 697 patients reviewed, 319 were considered low risk for PE using Well’s criteria. D-dimer was ordered in only 89 of these low risk patients. Overall, 16 of 319 CTAs were positive (5.0%) in the low risk patient group. Of the 89 patients in whom D-dimer was performed, 24 had a negative D-dimer (<0.5 µg/mL), all of which yielded negative CTA. Of the 65 patients with positive D-dimers, 5 demonstrated PE on CTA (avg. D-dimer = 7.23 µg/mL). Of 230 patients in whom a CTA was performed without D-dimer being ordered, 11 were found to have CT findings suspicious for PE (4.8%). CONCLUSION Data suggests that we are underutilizing D-dimer, and not effectively using that D-dimer value when it is obtained; for both of these reasons CTAs are not being ordered efficiently. This is evidenced by the low rate of positive CTAs in our selected patient group, (5.0%) and high number needed to treat (20). By being more discerning in pursuing CTA to evaluate for PE, we can reduce costs ($27 per D-dimer versus $2,104 per CTA) and patient radiation exposure (7 mSv per CTA), while also allowing our radiologists more time to focus on more strongly indicated studies. We have since proposed to the ED that all patients meeting “low-risk criteria” have a D-dimer. We have begun collecting prospective data on patients in whom PE is considered; documenting Wells score, D-dimer and CTA results. CLINICAL RELEVANCE/APPLICATION Excessive ordering of CTA to “rule out” PE results in increased costs, and patient radiation exposure, as well as taking up the time of our radiologists. ER217-SDMOB5 The Utility of Early CT of Patients with a First Attack of Acute Pancreatitis in Emergency Department Station #5 Participants So Hyun Park, MD, Incheon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Seung Joon Choi, Incheon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Young Sup Shim, MD, Incheon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Sungjin Yoon, Incheon, Korea, Republic Of (Presenter) Nothing to Disclose PURPOSE Contrast-enhanced computed tomography (CT) is considered a diagnostic tool of acute pancreatitis (AP) and ideal time is after 72 hours from onset of symptoms. However, in the emergency department (ED), CT has been used in the early stage of AP recently. This study is to investigate whether early CT affects clinical management of AP. METHOD AND MATERIALS Of 116 consecutive adults of AP with a first attack in the ED between March 2015 and March 2016, 56 patients (56/116, 48.3%) of AP (M:F, 34:22; 50.3 ±15.6) underwent CT in the ED within 48 hours from onset of symptoms. CT images were retrospectively evaluated for the stage of AP and assessment of complications. Urgent clinical management including endoscopic retrograde cholangiopancreatitis (ERCP), percutaneous drainage (PCD) or percutaneous transhepatic biliary drainage (PTBD) within 24 hours after early CT was assessed in AP patients. RESULTS Of 56 patients, four patients showed acute necrotizing pancreatitis (3 patients in peripancreatic tissue only, 1 in both pancreas and peripancreatic tissue) and 52 patients had acute interstital pancreatitis. Alcohol abuse (25/56, 44.6%) and biliary obstruction or cholangitis (20/56, 35.7%) were the most common causes of AP. Of 20 biliary pancreatitis, 11 received urgent therapeutic ERCP (mean time interval between CT and ERCP, 11.4 ± 5.4). Of 11 patients, 5 received stone removal from the common bile duct (CBD) and endoscopic sphincterotomy (EST), 2 received interposition of biliary stent, 2 underwent EST, 1 underwent removal of pancreatic ductal stones, and 1 underwent CBD stone removal. CONCLUSION In conclusion, early CT is useful when a patient suspected of acute biliary pancreatitis and could be applied in clinical management of AP. CLINICAL RELEVANCE/APPLICATION Early CT may be useful in diagnosis and management of suspicious acute biliary pancreatitis. ER172-EDMOB6 CT Evaluation of Suspected Small Bowel Obstruction and Its Etiology. The Role of CT/CTA with Multiplanar and 3D Imaging in Diagnosis, Determining Cause, Identifying Complications and Guiding Patient Management: An Interactive Quiz Station #6 Participants Christopher R. Bailey, MD, Baltimore, MD (Presenter) Nothing to Disclose Pamela T. Johnson, MD, Baltimore, MD (Abstract Co-Author) Consultant, National Decision Support Company Elliot K. Fishman, MD, Baltimore, MD (Abstract Co-Author) Institutional Grant support, Siemens AG; Institutional Grant support, General Electric Company; TEACHING POINTS MDCT has become the primary imaging modality for patients with small bowel obstruction. Evidence in the literature underscores the importance of multiplanar evaluation to optimally interpret these studies.Following review of the exhibit the user will understand the role MPR/3D imaging in detection and differential diagnosis of small bowel obstruction recognizethe various CT appearances of small bowel obstruction learn how specific CT findings help define the cause of small bowel obstruction be cognizant of CT findings that define the urgency of surgical management TABLE OF CONTENTS/OUTLINE Critical CT findings for each diagnosis are emphasized and the importance ofhigh value interpretations to guidemanagement of these patients.Case studies (10) in quiz formatwith specific diagnosis include: SBO due to adhesions from prior surgery SBO following robotic prostatectomy andport site hernia incarcerated inguinal hernia internal hernia with midgut volvulus SBO secondary to volvulus with SMA and SMV occlusion as well as bowel infarction obstruction due to intussuception of a primary small bowel tumor obstruction due to intussuception of a metastatic tumor to the small bowel obstruction due to stricture from Crohn's disease SBO due to radiation enteritis SBO due to gallstone ileus Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Elliot K. Fishman, MD - 2012 Honored Educator Elliot K. Fishman, MD - 2014 Honored Educator Elliot K. Fishman, MD - 2016 Honored Educator Pamela T. Johnson, MD - 2016 Honored Educator SSE06 Emergency Radiology (Thoracoabdominal Emergencies) Monday, Nov. 28 3:00PM - 4:00PM Room: N227B GI GU CT ER AMA PRA Category 1 Credit ™: 1.00 ARRT Category A+ Credit: 1.00 Participants Jamlik-Omari Johnson, MD, Atlanta, GA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press Stephan W. Anderson, MD, Boston, MA (Moderator) Nothing to Disclose Sub-Events SSE06-01 Absent Secondary Signs of Appendicitis When the Appendix is Not Visualized Monday, Nov. 28 3:00PM - 3:10PM Room: N227B Awards Student Travel Stipend Award Participants Saad Hussain, MD, New Haven, CT (Presenter) Nothing to Disclose Vivek Patel, MD, New Haven, CT (Abstract Co-Author) Nothing to Disclose Aditi Vyas, MD, Norwalk, CT (Abstract Co-Author) Nothing to Disclose Mahan Mathur, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Mike Spektor, MD, New Haven, CT (Abstract Co-Author) Nothing to Disclose PURPOSE The purpose of this study is to determine the negative predictive value (NPV) of the sonographic secondary signs of appendicitis when the appendix is not visualized. The secondary signs of appendicitis seen on ultrasound (US) include free fluid, hyperemia, lymphadenopathy, and phlegmon formation. METHOD AND MATERIALS A retrospective review was completed looking for ultrasound images and reports that did not visualize the appendix in its entirety and also specifically stated that no secondary signs of appendicitis were visualized. The review spans 2013-2015. 130 studies were found meeting the inclusion criteria. RESULTS Of the 130 total studies, 95 did not have imaging follow up or surgery for appendicitis. Either the ultrasound revealed an alternate diagnosis (example: mesenteric adenitis) or the patient was discharged with an alternate clinical diagnosis (example: constipation). 35 studies had follow up imaging with CT (31), MRI (2) or US (2). Of the 31 follow up CTs, 4 did not visualize the appendix (and the patients were discharged) and the remaining 27 revealed normal appendices. The 2 MRI examinations showed normal appendices and the patients were discharged. One repeat ultrasound was negative and the patient was discharged. The other repeat ultrasound was positive and the patient was taken to surgery and had pathology proven appendicitis.The negative predictive value for absent secondary signs of appendicitis when the appendix is not visualized is 97%. CT, MRI, and repeat US that visualized a negative appendix were considered true negatives. CONCLUSION When the appendix is not visualized clinicians are often left to make a decision on whether or not to subject the patient (often pediatric) to ionizing radiation (CT), a lengthy MRI or a repeat US. It is important that radiologists and technologists look for the secondary signs of appendicitis when the appendix is not visualized. The radiologist should specifically mention the lack of secondary signs when appropriate. Based on the findings of this study, such a statement carries a high NPV. Armed with such information, the clinicians will be better suited in making the difficult decision in regards to further imaging or intervention. CLINICAL RELEVANCE/APPLICATION Secondary signs of appendicitis carry a high negative predictive value and should be evaluated for when the appendix is not visualized on ultrasound. SSE06-02 Evaluation of the Diagnostic Value of a Venous Phase in CT Angiography of the Extremities in the Setting of Trauma Monday, Nov. 28 3:10PM - 3:20PM Room: N227B Participants Zachary Masi, MD, Camden, NJ (Presenter) Nothing to Disclose Kathryn Gussman, Camden, NJ (Abstract Co-Author) Nothing to Disclose Joshua Hazelton, DO, Camden, NJ (Abstract Co-Author) Nothing to Disclose Ron Gefen, MD, Camden, NJ (Abstract Co-Author) Nothing to Disclose PURPOSE Patients with traumatic injury to extremities are often evaluated at hospital trauma centers by computed tomography angiography (CTA) to evaluate for vascular injury, which can utilize arterial and venous phases. The purpose of this study is to assess whether the venous phase contributes added value to the diagnostic study. METHOD AND MATERIALS Institutional IRB approval was obtained. Retrospective analysis of a radiology information system at a level I trauma center identified adult patients evaluated for injury by upper or lower extremity CTA between September, 2014 and September, 2015 with both arterial and venous phases. Images were evaluated by a diagnostic radiologist for diagnosis of “no injury”, “arterial injury”, “venous injury” or “vasospasm”, made by the arterial phase alone, or in conjunction with the venous phase. Statistical analysis utilized McNemar test and Kappa agreement values (a p value of < 0.05 was considered significant). RESULTS There were 157 studies performed on 154 patients, 131 (83%) male and 23 (17%) female (mean age 39). Studies comprised 49 upper and 108 lower extremities. Most common mechanisms of injury were gunshot wound (63), motor vehicle accident (26), and stab wound (13). There were 99 diagnoses of no injury, 35 arterial injuries, 16 vasospasms, and 7 venous injuries. Four diagnoses were changed between interpreting the arterial phase alone and both phases together: three venous injuries including one deep vein thrombosis, and one vasospasm. Only the case of deep vein thrombosis resulted in a change in clinical management. Overall there was no significant difference in diagnosis between the two methods (p > 0.125). There was high agreement for diagnosis of no injury (Kappa 0.99), arterial injury (0.96), and vasospasm (0.97), and moderate agreement in diagnosing venous injury (0.59) (p < 0.001). CONCLUSION The venous phase of CTA extremity studies for trauma does not add statistically significant value in diagnosing vascular injury and can be safely removed from the imaging protocol, thereby decreasing patient scan time and radiation dose. CLINICAL RELEVANCE/APPLICATION CT angiography studies of extremities for vascular trauma can be accurately performed with an arterial phase only and do not require a venous phase. SSE06-03 Toward an MDCT-based Decision Support Tool for Bleeding Pelvic Fractures using Semi-automated Volumetric Hematoma Analysis and Probabilistic Modeling: Preliminary Results Monday, Nov. 28 3:20PM - 3:30PM Room: N227B Participants David Dreizin, MD, Baltimore, MD (Presenter) Nothing to Disclose Nikki Tirada, MD, Brookline, MA (Abstract Co-Author) Nothing to Disclose Uttam Bodanapally, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Eliot L. Siegel, MD, Baltimore, MD (Abstract Co-Author) Board of Directors, Brightfield Technologies; Board of Directors, McCoy; Board of Directors, Carestream Health, Inc; Founder, MedPerception, LLC; Founder, Topoderm; Founder, YYESIT, LLC; Medical Advisory Board, Bayer AG; Medical Advisory Board, Bracco Group; Medical Advisory Board, Carestream Health, Inc; Medical Advisory Board, Fovia, Inc; Medical Advisory Board, McKesson Corporation; Medical Advisory Board, Merge Healthcare Incorporated; Medical Advisory Board, Microsoft Corporation; Medical Advisory Board, Koninklijke Philips NV; Medical Advisory Board, Toshiba Corporation; Research Grant, Anatomical Travelogue, Inc; Research Grant, Anthro Corp; Research Grant, Barco nv; Research Grant, Dell Inc; Research Grant, Evolved Technologies Corporation; Research Grant, General Electric Company; Research Grant, Herman Miller, Inc; Research Grant, Intel Corporation; Research Grant, MModal IP LLC; Research Grant, McKesson Corporation; Research Grant, RedRick Technologies Inc; Research Grant, Steelcase, Inc; Research Grant, Virtual Radiology; Research Grant, XYBIX Systems, Inc; Research, TeraRecon, Inc ; Researcher, Bracco Group; Researcher, Microsoft Corporation; Speakers Bureau, Bayer AG; Speakers Bureau, Siemens AG; Daniel C. Mascarenhas, BS, Cinnaminson, NJ (Abstract Co-Author) Nothing to Disclose Louis Bivona, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Edward H. Herskovits, MD, PhD, Baltimore, MD (Abstract Co-Author) Consultant, BioClinica, Inc; Shareholder, Galileo CDS, Inc; PURPOSE No single CT sign, including intravenous contrast extravasation (ICE), predicts the need for angioembolization with sufficient accuracy. ICE is only up to 60% sensitive. Active bleeding on angio (AB) is often seen w/o ICE. Pelvic hematoma volumes are predictive of AB, but have not been validated for point of care use because time consuming slice-by-slice segmentation was employed. We aimed to developed a multivariate probabilistic model and online calculator incorporating rapid pelvic hematoma segmentation. METHOD AND MATERIALS A retrospective cohort of 116 patients were selected. Inclusion criteria: age > 18, blunt pelvic trauma; arterial phase MDCT prior to angio. Exclusion criteria: no angio was performed; CT only after angio. Image review: data collected: presence/absence of ICE; greatest diameter of contrast blush (mm); # vessels with blush; hematoma volumes from seeded region growing segmentation(mL); fractures of the obturator canal or greater sciatic notch; pubic diastasis; osteopenia; age; gender. Stepwise logistic regression with forward selection and backward elimination was performed to determine informative variables for AB at angio. RESULTS The variable with the strongest correlation with AB was hematoma vol (p<0.001). Age and the greatest diameter of blush were also explanatory and included in the model. Osteopenia; fractures and diastasis; and # of vessels dropped out during successive forward selection and backward elimination steps. Logit transformation was performed to derive a probabilistic formula: P=e[(0.027*age)+ (0.004*hematoma vol)+(0.036*diameter largest blush)-3.014]/(1+e[(0.027*age)+(0.004*hematoma vol)+ (0.036*diameter largest blush)-3.014]). A prototype online active bleed calculator was developed- age(yrs) diameter(mm), and hematoma vol(mL) is entered to determine probability of AB. CONCLUSION Prior work using manual segmentation found that hematoma vols<200mL result in 5% likelihood of AB, and vols> 500mL have 45% likelihood. Our model provides a greater degree of practicality because 1) rapid segmentation can be done at the point of care, and 2) the model is highly granular.For example, an intermediate sized hematoma of 321 mL, even without blush, results in high likelihood (56%) of AB in an elderly (73yo) victim of blunt trauma. CLINICAL RELEVANCE/APPLICATION The proposed model can be used at the point of care to guide trauma/ER radiologists, interventionalists, and trauma surgeons in The proposed model can be used at the point of care to guide trauma/ER radiologists, interventionalists, and trauma surgeons in determining the need for angio. SSE06-04 Colonic Wall Thickening: Can Iodine Quantification Using Dual Source Dual Energy CT Differentiate Diverticulitis from Adenocarcinoma? Monday, Nov. 28 3:30PM - 3:40PM Room: N227B Participants Kathryn Darras, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Sheldon J. Clark, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Heejun Kang, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Alison C. Harris, MBChB, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Silvia D. Chang, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Mohammed F. Mohammed, MBBS, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Tim O'Connell, MD, Meng, Vancouver, BC (Abstract Co-Author) President, Resolve Radiologic Ltd Speake, Siemens AG Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Presenter) Speaker, Siemens AG PURPOSE To evaluate the role of iodine quantification in differentiating colonic diverticulitis from colonic adenocarcinoma. METHOD AND MATERIALS Institutional review board approval was obtained, with no informed consent required, for this retrospective analysis. 146 consecutive patients with acute diverticulitis were scanned using a standard protocol on a 128-section dual source, dual energy CT system (100/140 keV). Patients who did not have follow up colonoscopy, which served as the gold standard, or who received large volumes of positive oral contrast were excluded. This left 52 patients for analysis, 8 with proven colonic adenocarcinoma and 44 with diverticulitis. Using the virtual non-contrast application, iodine maps and virtual non-contrast datasets were created for all patients. The coloured iodine maps were superimposed onto the virtual non-contrast images to provide both iodine distribution and anatomic detail. The iodine concentration was recorded within the thickened bowel wall using a region of interest analysis (mg/ml). The two groups were compared using two tailed unpaired t tests and the sensitivity and specificity were established. RESULTS The average iodine concentration was 1.41±0.56 mg/ml (range 0.2-2.7 mg/ml) in bowel wall thickening due to diverticulitis and 3.15±0.57 mg/ml (range 2.5-4.3 mg/ml) in bowel wall thickening due to adenocarcinoma. This difference was statistically significant (p < 0.0001). Using a threshold of 2.5 mg/ml, the sensitivity for identifying adenocarcinoma was found to be 100% and the specificity 95.5%. CONCLUSION Using a threshold value of 2.5 mg/ml, dual energy CT iodine quantification was found to have a high sensitivity and specificity for distinguishing colonic wall thickening due to diverticulitis from thickening due to adenocarcinoma. CLINICAL RELEVANCE/APPLICATION Identifying the cause of colonic wall thickening, which is generally regarded as a nonspecific CT finding, will allow for appropriate patient referral and triage for colonoscopy. SSE06-05 Evaluation of Pancreatic Injury: Correlation between Pancreas Injury Grade (PIG) Scoring on MDCT and Clinical Features and other Organ Injuries Monday, Nov. 28 3:40PM - 3:50PM Room: N227B Participants Jung Hyun Noh, MD, Cheonan-si, Korea, Republic Of (Presenter) Nothing to Disclose Sang Wook Son, MD, Cheon-an, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Mi-Hyun Park, MD, Cheonan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Young-Seok Lee, MD, Cheonan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Keum-Nahn Jee, MD, PhD, Cheonan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose PURPOSE To assess the correlation of radiological PIG scoring on MDCT and clinical features and other associated organ injuries retrospectively METHOD AND MATERIALS 38 patients (mean age = 38.1, male to female ratio = 22 : 16), diagnosed as traumatic pancreatic injury by clinical and initial MDCT findings, were included from Mar. 2006 to Feb. 2016. Their imaging findings were analyzed about five-scale PIG scoring on MDCT based on AAST grade by consensus of two radiologists. Clinical records were reviewed about injury type, initial vital sign, hospitalization period, prognosis and treatment. Associated abdominal MDCT findings were analyzed about other hollow and solid visceral injury, vascular injury and injuries of other body parts. Evaluation of correlation between radiological PIG scoring on MDCT and other associated organ injuries, and clinical features was done using statistical analyses by Fisher’s exact test and KruskalWallis test. RESULTS Patients with PIG scoring scale from I to V on MDCT included 13, 5, 11, 7, and 2 patients. Among 38 patients, 23 patients (60.5%) had associated other organ injuries and 4 patients (10.5%) expired early due to unstable vital sign with active arterial bleeding in liver or abdominal cavity and their PIG scoring was grade I (n=2), grade III (n=1) and grade V (n=1). Their injury types were out car accident (n=3), in car accident (n=22), fall down (n=2) and blunt trauma (n=11). Patients with high PIG scoring had characteristics of associated duodenal injury, vascular injury, and treatment choice of operation with statistical significance (p < 0.05). And no statistical significant correlations were between PIG scoring and other associated organ injuries in abdomen except duodenal and vascular injury, interventional treatment, and other clinical findings of initial vital sign, injury type, hospitalization period and death rate. CONCLUSION Patients with high PIG scoring have the characteristics of associated duodenal and vascular injuries, and treatment choice of surgery. Associated other organ injuries and mortality cases were not correlated with PIG scoring. CLINICAL RELEVANCE/APPLICATION Evaluation of correlation degree between PIG scoring scale and associated every other organ injury and various clinical findings can be clinically meaningful and these results could be considered as a reference of clinical evaluation of pancreatic injury patient despite of limitation of number of included patients. SSE06-06 Focused Abdomino Pelvic CT in Children with Suspected Acute Appendicitis: Assessing Accuracy and Radiation Dose Reduction by Limiting the Scan Field Monday, Nov. 28 3:50PM - 4:00PM Room: N227B Awards Student Travel Stipend Award Participants Andrew Fox, MD, Montreal, QC (Presenter) Nothing to Disclose Christine Saint-Martin, MD, Montreal, QC (Abstract Co-Author) Nothing to Disclose PURPOSE Imaging is widely used in cases of suspected appendicitis with ultrasound the most common first-line modality in pediatric patients. When sonography is non-diagnostic, a complete abdominopelvic CT is often used as an adjunct to rule in the diagnosis prior to OR. CT has diagnostic superiority over sonography but the associated radiation is a concern and thus methods to reduce radiation are of great interest. The concept of Z-axis limitation with combined analysis of accuracy and radiation dose reduction is yet to be studied in the pediatric population. METHOD AND MATERIALS Data was collected from PACS between January 2010-present. The upper limit of the appendix was correlated with the superior endplate of the corresponding vertebra. Subsequently, an upper limit Z-axis for interpretation was set based on the average location of the appendix in our series (μ - 2σ), to include >97.5% of the visualized appendices. The studies were then revisited to assess diagnostic accuracy over this focused range, assessing detection of both primary pathology and incidental findings. Radiation dose reduction will be calculated using the Radimetrics software suite. RESULTS On the initial scans, the appendix was identified in 116/125 patients and not visualized in 9 patients. The average scan range was 438mm. 27 scans were positive for appendicitis and alternate pathology was identified in 17 patients. The average upper limit of the appendix minus 2 SD corresponded to the L2 vertebra. From L2 caudally, the appendix was completely visualized in 115 scans, and partially visualized in 1 scan. All of the positive appendicitis cases were diagnosed over the limited scan range. 10 alternate diagnoses were completely identified, and 2 were partially identified. 5 cases of pulmonary pathology were missed. The average Zaxis Delta was 141mm, corresponding to a 32% reduction in scan field. Radiation dose reduction is being calculated. CONCLUSION Focused abdominopelvic CT for appendicitis in the pediatric population reduces the scan range by approximately 32%, while maintaining 100% diagnostic accuracy for appendicitis (radiation dose reduction pending). Alternate abdominal pathology was either completely or partially identified over this limited range. CLINICAL RELEVANCE/APPLICATION By limiting the scanning range of CTs performed for appendicitis, we are hoping to significantly reduce radiation dose to the patient, while maintaining diagnostic accuracy. ED004-TU Emergency Radiology Tuesday Case of the Day Tuesday, Nov. 29 7:00AM - 11:59PM Room: Case of Day, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose David Dreizin, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Manickam Kumaravel, MD, FRCR, Houston, TX (Abstract Co-Author) Nothing to Disclose Constantine A. Raptis, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose David D. Bates, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thomas Battey, Timonium, MD (Abstract Co-Author) Nothing to Disclose Nicholas M. Beckmann, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1) Recognize key imaging findings on multimodality imaging of emergency/trauma patients. 2) Develop differential diagnosis based on the clinical information and imaging findings. 3) Recommend appropriate management including image-guided interventions. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator RC308 Emergency Radiology Series: Imaging of Thoracic and Related Emergencies Tuesday, Nov. 29 8:30AM - 12:00PM Room: N230B CH ER AMA PRA Category 1 Credits ™: 3.50 ARRT Category A+ Credits: 4.00 Participants Martin L. Gunn, MBChB, Seattle, WA, ([email protected]) (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press; Spouse, Consultant, Reed Elsevier; Spouse, Consultant, athenahealth, Inc; ; Stephen Ledbetter, MD, Boston, MA (Moderator) Nothing to Disclose Active Handout:Martin Lee David Gunn http://abstract.rsna.org/uploads/2016/16000652/RC308 Gunn Aortic Injury.pdf Sub-Events RC308-01 Esophageal Emergencies Tuesday, Nov. 29 8:30AM - 9:00AM Room: N230B Participants Francis J. Scholz, MD, Burlington, MA, ([email protected] ) (Presenter) Owner, FSpoon Company LEARNING OBJECTIVES After this presentation the radiologist will:Understand how to optimally examine for pharyngeal and esophageal trauma using fluoroscopyRecognize and stage trauma as either A. Mucosal Tear B Intramural Dissection C Transmural Tear ABSTRACT Esophageal trauma is common in practice and includes a broad spectrum of clinical and radiologic entities including perforation, hematoma, and foreign body ingestion that must be recognized promptly in order to reduce morbidity and mortality. Imaging findings are often subtle or may not be demonstrable by conventional radiography or CT. Recognizing subtle fluoroscopic findings of disease may avoid additional work up including more invasive endoscopy.Radiologists frequently perform esophageal fluoroscopy for not only possible spontaneous trauma but also complex post-surgical and endoscopic trauma. In addition, spontaneous or post traumatic pneumodemiatstinum or air in soft tissues of the neck lead to an urgent request to evaluate for esophageal perforation. This presentation will provide concise details of our fluoroscopic technique and the findings that permit staging of traumatic insults for clinical treatment choices, correlated with CT findings. Mucosal tears, intramural dissections, and transmural perforations are shown. Classic eponymic esophageal traumas - Boerhaave and Mallory Weiss - are discussed and illustrated. ABSTRACT Esophageal trauma is common in practice and includes a broad spectrum of clinical and radiologic entities including perforation, hematoma, and foreign body ingestion that must be recognized promptly in order to reduce morbidity and mortality. Imaging findings are often subtle or may not be demonstrable by conventional radiography or CT. Recognizing subtle fluoroscopic findings of disease may avoid additional work up including more invasive endoscopy.Radiologists frequently perform esophageal fluoroscopy for not only possible spontaneous trauma but also complex post-surgical and endoscopic trauma. In addition, spontaneous or post traumatic pneumodemiatstinum or air in soft tissues of the neck lead to an urgent request to evaluate for esophageal perforation. This presentation will provide concise details of our fluoroscopic technique and the findings that permit staging of traumatic insults for clinical treatment choices, correlated with CT findings. Mucosal tears, intramural dissections, and transmural perforations are shown. Classic eponymic esophageal traumas - Boerhaave and Mallory Weiss - are discussed and illustrated. Active Handout:Francis Joseph Scholz http://abstract.rsna.org/uploads/2016/16000653/rc30801 Esophageal Emergencies DONE 6p.pdf LEARNING OBJECTIVES 1) Understand presentations of esophageal trauma that warrant prompt fluoroscopic imaging. 2) Know esophageal anatomy and structure required for fluoroscopic imaging. 3) Use techniques that optimally define esophageal pathology. 4) Diagnose esophageal trauma, and stage perforations. ABSTRACT Esophageal emergencies are common and the radiologist is a key member of the team involved in the diagnosis, staging, and treatment of many esophageal emergencies. CT and Fluoroscopy remain the principle diagnostic tools in patients with emergent esophageal symptoms.Introduction to esophageal perforation, fluoroscopy and CT technique, diagnostic findings, and staging concepts will be discussed and illustrated, including classic diagnoses: Taco Tear, Mallory Weiss, Boerhaave SyndromeSigns and symptoms of esophageal trauma: odynophagia, pain after endoscopy, neck crepitus, abnormal breath sounds. PERFORATION ETIOLOGIES:Instrumentation and Surgery Ingestion/vomiting: Mallory Weiss, Boerhaave, Taco Tear, often alcohol associated Fragile mucosa: Bullous Dermatoses, Eosinophilic Esophagitis Radiation Stricture Caustic agentsTECHNIQUE:If critically ill: CT and/or straight to surgery. If not critically ill and high suspicion, fluoroscopy is the FIRST BEST TEST for esophageal trauma. It is best suited for finding subtle intramural perforations and for severity staging.FLUOROSCOPY:Review prior swallow, find prior stricture site Water-soluble, 90 cc, 4/s AP pharynx; 1/sec AP Esophagus. If negative: bariumEsophagus: 1/s, upright AP, LAO and prone LPO.Pharynx: 4/s AP, LateralESOPHAGEAL TRAUMA STAGINGMucosal Intramural Transmural Distant tracking, pleural and mediastinal inflammation RC308-02 Chest Pain CT in the Emergency Department: Watch Out the Myocardium Tuesday, Nov. 29 9:00AM - 9:10AM Room: N230B Participants Kai Higashigaito, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Ricarda M. Hinzpeter, MD, Zurich, Switzerland (Presenter) Nothing to Disclose Stephan Baumueller, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Hatem Alkadhi, MD, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose Fabian Morsbach, Zurich, Switzerland (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the frequency and significance of hypodense myocardium (HM) and coronary culprit lesions in chest-pain CT in the emergency department. METHOD AND MATERIALS In this IRB- and ethics committee approved study, ECG-triggered chest-pain CT examinations of 300 consecutive patients (mean age 59±17 years, 71% male) with acute chest pain referred to our emergency department for DRO (rule-out pulmonary embolism (PE) and aortic dissection (AD), n=179) and TRO (n=121) between 06/2012 and 11/2015 were retrospectively analyzed. Chest-pain CT for TRO was performed with s.l. nitroglycerine and without nitroglycerine for DRO. Each myocardial segment was assessed for the presence of hypodense myocardium (HM). Attenuation of HM was measured and compared to normal myocardium. Coronary arteries were searched for the presence of culprit lesions and coronary plaques were classified into non-calcified, mixed and calcified. Presence of positive remodeling was noted. Patient histories were reviewed for the indications of CT, cardiovascular risk factors, known previous myocardial infarction (MI), and final diagnosis causing acute chest pain. RESULTS HM was identified in 27/300 patients (9%): 12/179 in DRO-CT (7%) and 15/121 in TRO-CT (12%). Mean attenuation of HM (59±40HU) was significantly lower than that of healthy myocardium (112±20HU, p<0.05), with a mean difference of 83±32HU. In 16/27 patients (59%) with HM, the final diagnosis was acute MI, and in the remaining 11/27 patients (41%) previous MI was found in the patients’ history. DRO-CT identified HM and the corresponding culprit lesion in 6/16 patients (37%) with a final diagnosis of acute MI. In 13/16 patients (81%), a culprit lesion causing MI was correctly identified and subsequently confirmed with catheter angiography. Of the identified 13 plaques in culprit lesions, 4 (31%) were non-calcified, 4 (31%) mixed, and 5 (38%) calcified. 9/13 (69%) plaques showed positive remodeling. CONCLUSION Hypodense myocardium and the culprit coronary lesion causing acute MI is encountered often in chest-pain CT examinations, even if only a DRO-CT was performed. This indicates that the myocardium should be analyzed for hypodense regions also if no dedicated CT of the coronaries and heart was asked for. CLINICAL RELEVANCE/APPLICATION Acute MI can be detected in both DRO- and TRO- chest-pain CT examinations and may facilitate the diagnostic workup of acute chest pain patients. RC308-03 MDCT of Aortic Dissection Tuesday, Nov. 29 9:10AM - 9:40AM Room: N230B Participants Stephen Ledbetter, MD, Boston, MA, ([email protected]) (Presenter) Nothing to Disclose LEARNING OBJECTIVES To optimize imaging approach for the ED patient To review the typical CT imaging findings To understand the spectrum of disease RC308-04 Novel CT Predictors of Type A Aortic Dissection Tuesday, Nov. 29 9:40AM - 9:50AM Room: N230B Awards Student Travel Stipend Award Participants Nigel R. Munce, MD,PhD, Hamilton, ON (Presenter) Founder, Conavi Medical Inc; Shareholder, Conavi Medical Inc Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Ali Alsagheir, MD, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Forough Farrokhyar, DPhil, PhD, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Dominic Parry, MD, Hamilton, ON (Abstract Co-Author) Nothing to Disclose PURPOSE To retrospectively evaluate the clinical relevance of novel MDCT parameters in patients with type A aortic dissection when compared to a control group having MDCT for the evaluation of thoracic aorta. METHOD AND MATERIALS An IRB- approved retrospective review of patients presenting with Type A aortic dissection at our institution (n=51 with available An IRB- approved retrospective review of patients presenting with Type A aortic dissection at our institution (n=51 with available MDCT) was conducted from January 2008 - January 2016. MDCT parameters measured were: length of the ascending aorta (AA), maximal AA diameter, aortic root diameter, the left ventricular outflow tract (LVOT) angle (the angle between an imaginary line drawn at right angles to the plane of the aortic annulus and a second line representing the transverse plane) and the cardiac apex (CA) angle (the angle between an imaginary line drawn from left ventricular apex to the mid point of the aortic valve and a second line representing the transverse plane). Similar measurements were performed in an age and gender matched control group (n=76). Statistical comparison were made with Student’s t-tests. RESULTS 51 cases of acute Type A dissection with available MDCT were identified (mean age= 61; M:F= 35:16). Review of 123 urgent CTs of the complete aorta yielded 76 cases without significant acute aortic pathology or prior thoracic aortic intervention which served as age and gender matched controls. The mean length of the ascending aorta in the Type A dissection population versus control group was 12.00 vs 9.27 cm (p < .0001). The maximal aortic diameter was 4.97 vs 3.15 cm (p < .0001) and aortic root diameter was 4.35 vs 2.89 cm (p<.001). The LVOT and CA angles were both significantly less in the type A dissection group measuring 31.70 vs 44.13 degrees (p< .0001) and 20.44 vs 30.34 degrees (p <.0001), respectively. CONCLUSION Our study shows, for the first time to our knowledge, that there is a statistically significant increase in the length of the ascending aorta in patients with Type A dissection as compared to control group. We also demonstrate that there is a decrease in the angle of the LVOT and CA angle. CLINICAL RELEVANCE/APPLICATION AA length, LVOT angle and CA angle are significantly different in patients with Type A dissection as compared to a control group and thus may serve as novel predictors for type A aortic dissection. RC308-05 Morphological Changes between Acute and Chronic Type B Communicating Aortic Dissection on MDCT: A Retrospective Study Tuesday, Nov. 29 9:50AM - 10:00AM Room: N230B Participants Yumi Imamura, Tokyo, Japan (Presenter) Nothing to Disclose Satoru Morita, MD, PhD, Shinjuku-ku, Japan (Abstract Co-Author) Nothing to Disclose Shuji Sakai, MD, Shinjuku-Ku, Japan (Abstract Co-Author) Nothing to Disclose PURPOSE No reports have systematically clarified the differences between acute and chronic type B communicating aortic dissection on computed tomography (CT), though such clarification is sometimes required clinically. Thorough understanding of these differences from disease onset is important for determining optimal therapeutic methods and accurately estimating the prognosis. The purpose of this study was to compare the morphological changes between acute and chronic type B communicating aortic dissection on multidetector row CT (MDCT). METHOD AND MATERIALS We analyzed 21 patients with type B communicating aortic dissection who underwent acute-phase contrast-enhanced MDCT. The flap curvature, flap thickness, long and short diameter of the aorta, and false lumen length were measured at a representative portion of the descending aorta. The numbers of slices with 5-mm thickness with a fluttering flap, calcification on the flap, and thrombosis in the false lumen were counted. These findings in the acute and chronic phases before any intervention (median 0 and 181 days after onset) were compared using the Mann–Whitney U test. RESULTS The mean flap curvature in the acute phase was significantly larger than in the chronic phase (66.0 ± 18.0 vs. 35.5 ± 30.9 1/m, p = 0.009). The median number of slices with a fluttering flap in the acute phase was larger than in the chronic phase (10 vs. 1, p = 0.008). The mean ratio of the long to short diameter in the acute phase was relatively lower than in the chronic phase (1.07 ± 0.06 vs. 1.14 ± 0.12, p = 0.073). The mean ratio of the false lumen length to long diameter in the acute phase was significantly lower than in the chronic phase (0.41 ± 0.10 vs. 0.59 ± 0.16, p < 0.001). No significant differences in the mean flap thickness, median number of slices with calcification on the flap, and median number of slices with thrombosis in the false lumen were observed (2.4 ± 0.5 vs. 2.7 ± 0.6, p = 0.176; 8 vs. 10, p = 0.651; and 2 vs. 12, p = 0.086). CONCLUSION Acute and chronic type B communicating aortic dissection can be differentiated on MDCT. Findings suggestive of acute phase are a curved flap, flap fluttering, and complete round shape of the descending aorta. CLINICAL RELEVANCE/APPLICATION MDCT findings of a curved flap, flap fluttering, and complete round shape of the descending aorta suggest the acute rather than chronic phase of type B communicating aortic dissection. RC308-06 Aortic MRA Can Guide ED Management of Suspected Acute Aortic Dissection Tuesday, Nov. 29 10:00AM - 10:10AM Room: N230B Participants Gary X. Wang, MD, PhD, Boston, MA (Presenter) Nothing to Disclose Sandeep S. Hedgire, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thang Le, MD, Cambridge, MA (Abstract Co-Author) Nothing to Disclose Jonathan Sonis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Brian Yun, MD,MBA, Boston, MA (Abstract Co-Author) Nothing to Disclose Michael H. Lev, MD, Boston, MA (Abstract Co-Author) Consulant, General Electric Company; Institutional Research Support, General Electric Company; Stockholder, General Electric Company; Consultant, MedyMatch Technology, Ltd; Consultant, Takeda Pharmaceutical Company Limited; Consultant, D-Pharm Ltd Ali Raja, MD, MBA, Boston, MA (Abstract Co-Author) Nothing to Disclose Anand M. Prabhakar, MD, Somerville, MA (Abstract Co-Author) Nothing to Disclose PURPOSE Though ACR Appropriateness Criteria recommends MRA for suspected acute aortic dissection when CTA is not possible, the feasibility and utility of this strategy in the ED is unclear. This study examines the indications and outcomes of MRA in suspected acute aortic dissection evaluation in the ED. METHOD AND MATERIALS This study was completed in an urban, academic Level 1 trauma center. An IRB approved retrospective electronic medical record review identified patients who underwent MRA in the ED for suspected acute thoracic aortic dissection from 2010-2015. Age, gender, clinical assessment, CTA contraindications, MRA results, clinical outcomes, and times of ED arrival and dismissal, and of MRA completion were analyzed. RESULTS 47 patients (mean age 58 years old) underwent MRA: 19 (40%) due to iodinated contrast allergy, 21 (45%) due to renal insufficiency (eGFR < 30 ml/min/1.73 m² or clinical concern for declining renal function), 2 (4%) due to both, 2 (4%) to spare ionizing radiation, 2 (4%) for further work-up after CTA, and 1 (2%) due to prior contrast-enhanced CT within 24 hours. Mean ED arrival to MRA completion time was 381±279 min. 40 studies were fully diagnostic; 7 were limited. Two (4%) patients had acute dissection on MRA and 45 (96%) had negative exams. 18 (38%) received gadolinium: 14 (78%) had iodinated contrast allergy and none had renal insufficiency. 29 (62%) patients did not receive gadolinium: 21 (72%) had renal insufficiency and 2 (6%) were on hemodialysis; 7 (24%) had iodinated contrast allergy. No significant difference exists in ability to achieve a fully diagnostic MRA with or without gadolinium (p = 0.225, Fisher’s exact test). 16 (34%) of patients were discharged home from the ED; 2 (4%) were admitted for acute dissection seen on MRA and 29 (62%) for further evaluation after dissection was excluded or to manage an alternative diagnosis. CONCLUSION MRA has a clear role in the evaluation for acute thoracic aortic dissection in the ED, where it can guide management and facilitate safe discharge to home. Nearly all MRA exams in this study cohort were performed when CTA was not possible, which follows ACR Appropriateness Criteria and demonstrates its feasibility in the ED. CLINICAL RELEVANCE/APPLICATION With increased MRI availability in the ED, MRA can be useful in evaluating suspected acute aortic dissection in ED patients unable to undergo CTA and can allow for safe discharge to home. RC308-07 Advanced Imaging of Traumatic Thoracic Aortic Emergencies Tuesday, Nov. 29 10:10AM - 10:40AM Room: N230B Participants Martin L. Gunn, MBChB, Seattle, WA, ([email protected] ) (Presenter) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press; Spouse, Consultant, Reed Elsevier; Spouse, Consultant, athenahealth, Inc; ; Active Handout:Martin Lee David Gunn http://abstract.rsna.org/uploads/2016/16000655/ACTIVE RC308 07.pdf LEARNING OBJECTIVES 1) Review multi-modality imaging findings of traumatic thoracic aortic injuries. 2) Describe the most appropriate use of CT in the patient at risk of traumatic aortic injury. 3) Explain recent advances in the understanding of blunt aortic injuries, and current evidence-based management. 4) Identify imaging pitfalls and explain how to differentiate "pseudo-disease" from a true injury. ABSTRACT RC308-08 The Incidence and Effect on Mortality of Costochondral Fractures in Blunt Polytrauma Patients- A Review of 1461 Consecutive Whole Body CT Studies for Trauma Tuesday, Nov. 29 10:40AM - 10:50AM Room: N230B Awards Student Travel Stipend Award Participants Mari Nummela, MD, Helsinki, Finland (Presenter) Nothing to Disclose Frank Bensch, MD, PhD, Helsinki, Finland (Abstract Co-Author) Nothing to Disclose Seppo K. Koskinen, MD, PhD, Stockholm, Sweden (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the incidence of costal cartilage fractures (CCfx’s) in blunt polytrauma patients, related injuries, trauma mechanism and mortality. METHOD AND MATERIALS All patients with a history of blunt trauma in a level I trauma center over a period of 36 months were included. All whole body CT (WBCT) studies were initially double read and retrospectively reviewed by a board certified radiologist blinded to initial reports. RESULTS A total of 1461 WBCT studies were found, of which 574 (39%) had thoracic injuries (M 425; 74.0%, mean age 46.6 (range 18-91), F 149; 26.0%, mean age 48.9 (range 18-97)). Of these, 118 patients (M 101; 85.6%, mean age 48.8 (range 18-84), F 17; 14.4% mean age 47.4 (range 20-82)) had a total of 225 CCfx’s. The incidence of CCfx’s was 8.1% (118/1461) in all WBCT studies and 20.6% (118/574) in thoracic trauma patients. CCfx’s were categorized as costochondral (101; 44.9%), midchondral (112; 49.8%) or costosternal (12;5.3%). Costal cartilages of ribs 6 (37/225; 16.4%) and 7 (38/225; 16.9%) were most commonly injured. Multiple CCfx’s were found in 50% (59/118) and 16/118 patients (13.6%) had bilateral CCfx’s. No correlation between CC calcifications and fractures was found. However, posttraumatic calcifications were seen adjacent or in the fracture line on follow up CT-studies of 16 patients starting from 21 days after initial trauma. No internal mammary or subclavian artery injuries were detected. Acute traumatic aortic injury was rare (4/118; 3.4%). Multiple bony rib fx’s occurred in 96 cases of 118 (81.4%) of which 42 cases had bilateral fx’s. Associated intrathoracic injuries were pneumothorax (76; 64.4%), hemothorax (61; 51.7%), and pulmonary contusions (62; 52.5%). Intra-abdominal injuries were seen in 29 patients (24.6%). The main trauma mechanisms were MVA (40; 33.9%) and fall (34; 28.8%). The 30-day mortality of patients with CCfx’s was 7.63% (9/118) in comparison to 4.61% (21/456) of patients with no CCfx’s (OR 1.71, 95% CI (0.762-3.839)). CONCLUSION Costochondral fractures are common in blunt thoracic trauma. CC fx’s are related to high-energy trauma; patients with CCfx’s had a slightly higher mortality rate than thoracic trauma patients with no CCfx’s. CLINICAL RELEVANCE/APPLICATION Costochondral fractures increase rib cage instability and often contribute to the formation of a flail chest. They are usually painful and may impair respiratory function of chest trauma patients. RC308-09 Prognostic Value of CT-derived Left Atrial and Left Ventricular Measures in Patients with Acute Chest Pain Tuesday, Nov. 29 10:50AM - 11:00AM Room: N230B Participants Paul Apfaltrer, MD, Vienna, Austria (Presenter) Nothing to Disclose Rozemarijn Vliegenthart, MD, PhD, Groningen, Netherlands (Abstract Co-Author) Nothing to Disclose U. Joseph Schoepf, MD, Charleston, SC (Abstract Co-Author) Research Grant, Astellas Group; Research Grant, Bayer AG; Research Grant, General Electric Company; Research Grant, Siemens AG; Research support, Bayer AG; Consultant, Guerbet SA; ; ; John W. Nance JR, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Richard A. Takx, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE The aim of this study was to determine the prognostic value of computed tomography (CT)-derived measures of left ventricular (LV) and left atrial (LA) geometry and function for future major adverse cardiac events (MACE). METHOD AND MATERIALS We retrospectively analyzed data of 225 subjects who had undergone coronary CT angiography (CCTA) using a dual-source CT system for acute chest pain evaluation between September 2006 and March 2009. LV mass, LV ejection fraction (EF), LV endsystolic volume (ESV) and LV end-diastolic volume (EDV), LA ESV and LA diameter, septal wall thickness and cardiac chamber diameters were measured. MACE was defined as cardiac death, non-fatal myocardial infarction, unstable angina, or late revascularization. The association between cardiac CT measures and the occurrence of MACE was quantified using Cox proportional hazard analysis, adjusting for traditional risk factors (age, sex, body mass index, hypertension and Framingham risk score), coronary calcium score, and obstructive coronary artery disease on CCTA. RESULTS 225 subjects (mean age±SD, 56.2±11.2; 140 males) were analyzed, of whom 42 (18.7%) experienced a MACE during a median follow-up of 13 months (range 9-17 months). LA diameter (HR: 1.07, 95% confidence interval [CI] 1.01-1.13 per mm) and LV mass (HR: 1.05, 95% CI 1.00-1.10 per gram) remained significant prognostic factor of MACE after controlling for Framingham risk score. LA diameter and LV mass were also found to have prognostic value independent of each other. The other morphologic and functional cardiac measures were no significant prognostic factors for MACE. CONCLUSION CT-derived LA diameter and LV mass are associated with future MACE in patients undergoing evaluation for chest pain, and portend independent prognostic value beyond traditional risk factors, coronary calcium score, and obstructive coronary artery disease on CCTA. CLINICAL RELEVANCE/APPLICATION The results of the study indicate that CT-derived left atrial diameter and left ventricular mass are prognostic markers of cardiovascular events in patients with acute chest pain independent of traditional risk factors, coronary calcium score, and obstructive coronary artery disease on coronary CT angiography. RC308-10 Multi-modality Imaging of Deep Venous Thrombosis Tuesday, Nov. 29 11:00AM - 11:30AM Room: N230B Participants Douglas S. Katz, MD, Mineola, NY, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) To review the multi-modality current imaging of deep venous thrombosis (DVT) of the upper and lower extremities. 2) To review the advantages and disadvantages of the individual modalities for imaging known or suspected DVT in the upper and lower extremities - ultrasound, CT, MR, and conventional venography. 3) To demonstrate typical and less typical examples of acute as well as chronic DVT. 4) To review the potential pitfalls in the imaging of DVT. ABSTRACT Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator RC308-11 A Review of Modified Well's Criteria Score as a Predictor of Lower Limb Venous Thromboembolism Tuesday, Nov. 29 11:30AM - 11:40AM Room: N230B Participants Ronan Waldron, BMBCh, Galway, Ireland (Abstract Co-Author) Nothing to Disclose Brian M. Moloney, MBBCh, Galway, Ireland (Presenter) Nothing to Disclose Mary Clare Casey, Co Mayo, Ireland (Abstract Co-Author) Nothing to Disclose PURPOSE We aim to assess the use of the Modified Wells Criteria (MWC) score as a determinant for eligibility for Doppler Ultrasound (DUS) and to determine the diagnostic accuracy of D-Dimers in positively predicting the presence of deep venous thrombosis (DVT) METHOD AND MATERIALS All patients who underwent lower limb DUS following suspicion of DVT between November 2012 and September 2014 were reviewed. Pre-imaging MWC score was recorded and D-Dimer result noted if performed. RESULTS A total of 764 patients underwent lower limb DUS. 415(54.3%) of patients involved were female. 10.34% (n=80) of those who underwent Lower Limb DUS had a positive finding of DVT. 364 patients had a MWC Score of 2, with a positive result in 23(6.32%). 257 patients had a MWC Score of 3, with a positive result in 24 (9.33%). 114 patients had a MWC score of 4, with a positive result for DVT identified in 21 (18.42%). 29 patients had a MWC score of 5, 9(31.01%) of whom had a DVT. 7 patients had a MWC score of 6, with a positive result for DVT in 3 (42.85%). The most common presenting symptoms were lower limb oedema (n= 731, 95.7%) and pain (n=715, 93.6%). D-Dimer was elevated in all cases it was performed (n=564 (73.8%)). A mean elevation of 6.3 times normal level was recorded with a DVT diagnosed at DUS. CONCLUSION Requests for DUS has increased significantly over the past decade in order to provide diagnostic certainty with consequent significant burden on radiology services. The low positive outcome (10.3%) following DUS, as compared to antiquated international comparisons of 12-25% supports suggestions of a deluge in reliance on this investigation for a negative diagnosis. Average pre-test MWC scores suggested the majority of patients were within ‘likely range” for existence of a lower limb DVT, which may suggest a need to reassess interpretation of the MWC CLINICAL RELEVANCE/APPLICATION Venous thromboembolism is a common cause of morbidity and a potentially fatal complication of hospitalization. DVT is the most common form of venous thrombosis with an estimated incidence of 67 per 100,000 in the general population and a cumulative lifetime incidence of 2 to 5%. The diagnosis of DVT is initially based on clinical suspicion, clinical examination and the use of the MWC. DUS is only indicated to confirm the diagnosis of a DVT in a patient with a MWC score of two or greater. A D-Dimer test may be utilized as an adjunct to an elevated MWC score to support a diagnosis. RC308-12 Clinical Utility of CT Pulmonary Angiography in the Emergency Department when Providers Override Evidence-Based Clinical Decision Support Tuesday, Nov. 29 11:40AM - 11:50AM Room: N230B Awards Student Travel Stipend Award Participants Zihao Yan, BS, Boston, MA (Presenter) Nothing to Disclose Ali Raja, MD, MBA, Boston, MA (Abstract Co-Author) Nothing to Disclose Ivan Ip, MD, MPH, Brookline, MA (Abstract Co-Author) Nothing to Disclose Joshua Kosowsky, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jeremiah Schuur, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Ramin Khorasani, MD, Boston, MA (Abstract Co-Author) Consultant, Medicalis Corp PURPOSE Assess frequency of clinically useful diagnoses other than pulmonary embolism (PE) found on CT pulmonary angiography (CTPA) in emergency department (ED) patients with suspected PE when providers’ imaging request is inconsistent with evidence-based clinical decision support (CDS). METHOD AND MATERIALS This Institutional Review Board-approved study was performed at a tertiary-care, academic medical center ED with approximately 60,000 annual visits. We included all adult patients with suspected PE undergoing CTPA between 1/1/2011-8/31/2013. Each order was exposed to CDS based on the Wells Criteria. We compared the frequency of clinically useful alternative diagnoses (alternative diagnoses/ number of CTPAs) when providers overrode CDS alerts (e.g., CTPAs in patients with Well Score (WS) ≤4 with normal or no–D-dimer) to orders adherent to CDS (CTPAs in patients with WS >4 or WS ≤4 with elevated D-dimer). We defined clinically useful alternative diagnosis as imaging findings other than PE that could potentially explain the patient’s signs and symptoms (e.g. shortness of breath) and result in changes in clinical management within 3 months (e.g. thoracentesis 2 days post-CTPA for pleural effusion not seen on prior X-ray). Incidental findings resulting in changes in clinical management within 3 months (e.g. newly discovered enlarged mediastinal or hilar lymph nodes resulting in oncology admission) were also included. We hypothesized 20% rate of alternative diagnoses in the CDS adherent group, and 35% in the non-adherent group, requiring a sample size of 138 CTPAs in each group to provide 80% power (α = 0.05; two-tailed test). After removing positive PE studies in both groups, 150 CTPAs were randomly selected from each group. We performed patient chart review to investigate existence of alternative diagnosis. Chisquared test was used for statistical analysis. RESULTS Among 2993 CTPA studies, 589 studies were performed against CDS recommendations. The frequency of alternative diagnoses in the override group was 32% (48/150), compared to 15% (22/150) in the adherent group (p< 0.001). CONCLUSION CTPAs performed against the recommendation of evidence-based CDS were more than twice as likely to result in alternative diagnoses. CLINICAL RELEVANCE/APPLICATION CTPA use inconsistent with evidence-based CDS may provide clinical utility in nearly 1/3 of patients, prompting further research to determine if alternative tests would be more optimal in such patients. RC308-13 Cardiac and Hemodynamic Effects of Arterial Obstruction in Cancer-related Acute Pulmonary Embolism Tuesday, Nov. 29 11:50AM - 12:00PM Room: N230B Participants Juana M. Plasencia-Martinez, MD, Murcia, Spain (Presenter) Nothing to Disclose Alberto Carmona-Bayonas, MD, Murcia, Spain (Abstract Co-Author) Nothing to Disclose David Calvo-Temprano, MD, Oviedo, Spain (Abstract Co-Author) Nothing to Disclose Paula Jimenez-Fonseca, MD, Oviedo, Spain (Abstract Co-Author) Nothing to Disclose PURPOSE To analyze the impact of acute pulmonary embolism (PE) on right ventricle (RV), and their hemodynamic effects in patients with cancer. METHOD AND MATERIALS 303 consecutive patients with symptomatic cancer-related PE were ambispectively enrolled in the multicenter (14 hospitals) observational EPIPHANY study. All PEs were diagnosed by computed tomography pulmonary angiography. Arterial obstruction severity was quantified with the Qanadli index (QI). Patients were stratified by PE location as central (trunk, main and/or lobar) or peripheral (segmentary and/or subsegmentary branches). RV-dysfunction signs were defined as dilated RV (≥39 mm), increased right-to-left ventricle (RV/LV) diameter ratio (≥1) and abnormal (flattened or inverted) interventricular septum (IVS). RESULTS Mean QI scores were higher in subjects with dilated RVs (30.4±21.7 vs. 23.6±18.5, P=0.007) and abnormal IVSs (39.5±20.7 vs. 22.1±18.2, P<0.001). QI measurements correlated with the RL/LV ratio and RV diameter (r=0.39 and 0.28, respectively, P<0.001). Correlation between QIs and systemic blood pressure (SBP) was weak overall. However, progressively decreased heart adaptive capacity, as expressed by dilated RVs or abnormal IVSs, QI showed an inverse correlation with SBP that increased gradually (r=0.56, P=0.09; r=-0.998, P<0.001, respectively). Correlations between QI measurements, RV/LV ratios and RV diameters were stronger in hypotensive subjects (r=0.55 and r=0.64, respectively, P<0.001). In subjects with RV-dysfunction, the QI increased from normotensive to hypotensive patients (28.7±21.8 vs. 42.1±17.6, P=0.004). All those effects were unrelated with PE location (central or strictly peripheral). CONCLUSION In acute pulmonary embolism, the arterial obstruction index, assessed by Qanadli index, affects the hemodynamic status, but only when the right-sided heart adaptive capacity fails. CLINICAL RELEVANCE/APPLICATION The evaluation of right ventricular dilation by CT pulmonary angiography is more useful than the degree of occlusion of the pulmonary vasculature in predicting the outcome of cancer-related pulmonary embolism, likely because it evaluates better the hemodynamic impact of the increased afterload produced by PE on ventricular function, especially in patients with reduced cardiac contractility ERS-TUA Emergency Radiology Tuesday Poster Discussions Tuesday, Nov. 29 12:15PM - 12:45PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 FDA Discussions may include off-label uses. Participants Jamlik-Omari Johnson, MD, Atlanta, GA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press Martin L. Gunn, MBChB, Seattle, WA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press; Spouse, Consultant, Reed Elsevier; Spouse, Consultant, athenahealth, Inc; ; Sub-Events ER218-SDTUA1 Potentially Important Unreported Incidental Findings in Urgent Nonenhanced Abdominal CT Performed for Renal Colic Station #1 Participants Elena Belloni, MD, Castel San Giovanni, Italy (Abstract Co-Author) Nothing to Disclose Paola Scagnelli, Castel san Giovanni, Italy (Abstract Co-Author) Nothing to Disclose Ilaria Fiorina, Pavia, Italy (Presenter) Travel support, Shenzhen Mindray Bio-Medical Electronics Co, Ltd; Consultant, Esaote SpA; Consultant, Shenzhen Mindray Bio-Medical Electronics Co, Ltd; Consultant, SuperSonic Imagine; Consultant, Hitachi, Ltd; Consultant, Toshiba Corporation PURPOSE To retrospectively evaluate the prevalence of potentially important unreported incidental findings in consecutive nonenhanced abdominal CTs performed specifically for renal colic in the urgent setting. METHOD AND MATERIALS One radiologist with eight years of experience in CT (two as resident and six as specialist) retrospectively evaluated 156 consecutive nonenhanced abdominal CTs performed specifically for renal colic in 156 patients from the Emergency Department. The incidental findings, both urinary and extraurinary, were classified as potentially important if they required further imaging and/or clinical workup. The radiologist was blinded to the potentially important incidental findings highlighted in the finalized reports performed in the urgent setting, but was aware of the reports of previous radiological examinations, if any. It was evaluated if the CTs were performed, and the report generated, in the morning shift (hrs 8-14), in the afternoon shift (hrs 14-20) or in the night shift (hrs 20-8). RESULTS The 156 patients in the study were 104 males and 52 females, aged 51 ± 15 years (range 24-89 years). 98 CTs were performed and reported in the morning shift, 49 in the afternoon shift, 9 in the night shift. In the finalized reports, 19 potentially important incidental findings in 19 different CTs were highlighted (12.2%), 10 in the morning, 8 in the afternoon and 1 at night. The blinded retrospective evaluation confirmed all the 19 reported findings and added 24 unreported potentially important incidental findings in 24 different CTs (13 in the morning, 8 in the afternoon, 3 at night) (total of 43 findings in 156 CTs, 27.6%) (p<0.01). CONCLUSION A fair amount of potentially important additional findings was present in urgent nonenhanced abdominal CTs performed for renal colic. Even in the urgent setting, when the radiologist is under pressure, care should be taken to avoid underreporting (that in our series was particularly frequent in the night shift) and its possible consequences. CLINICAL RELEVANCE/APPLICATION CT is a pan-exploratory radiologic technique. For this reason, the radiologist should evaluate every body part included in the fieldof-view, in order to avoid underreporting, even in the urgent setting. ER220-SDTUA3 Retrospective Study of the Clinical Predictors of a Positive Abdominal Renal CT Scan in Patients Suspected to Nephro-ureteral Obstruction Station #3 Awards Student Travel Stipend Award Participants Francisco E. Valles, MD, Bridgeport, CT (Presenter) Nothing to Disclose Nisarg A. Parikh, MD, MBBS, Bridgeport, CT (Abstract Co-Author) Nothing to Disclose Yogesh Kumar, MD, Bridgeport, CT (Abstract Co-Author) Nothing to Disclose Stephen Stein, MD, Westport, CT (Abstract Co-Author) Nothing to Disclose Scott C. Williams, MD, Westport, CT (Abstract Co-Author) Nothing to Disclose PURPOSE Renal CT scans are often used to evaluate patients suspected of having renal colic, which are often negative despite best clinical judgement. The purpose of this retrospective study is to aid clinicians to more selectively order renal CT scans, thereby minimizing radiation risk to those with a low likelihood of a positive result. METHOD AND MATERIALS A retrospective study of 200 consecutive patients who arrived at a Level I trauma center and subsequently underwent a renal CT scan. Indications for renal CT scan were analyzed statistically using univariate and multivariate models. RESULTS Univariate chi-square tests showed pyuria (OR=2.41; 95% CI; P=0.02) was a predictor of positive renal CT scan. Unilateral flank pain (OR=2.00; 95% CI; P=0.06) and male sex (OR=1.81; 95% CI; P=0.05) had a tendency towards predicting a positive renal CT scan. Multivariate logistic regression demonstrated that males with unilateral pain (OR=2.14; 95% CI; P=0.02), males with hematuria (OR=3.01; 95% CI; P=0.01), and males with pyuria (OR=3.17; 95% CI; P=0.01) were significant predictors of positive renal CT scan. Males with unilateral flank pain and hematuria (OR=4.09; 95% CI; P=0.002), and males with unilateral flank pain, pyuria and hematuria (OR=4.52; 95% CI; P=0.01) yielded the highest likelihood of predicting a positive renal CT scan. Women with non-lateral pain were statistically more likely to have a negative CT scan (P<0.0001). CONCLUSION Our data suggests that pyuria is a significant risk factor for a positive renal CT scan in both men and women. Males with unilateral flank pain, hematuria and/or pyuria have a statistically significant risk for a positive renal CT scan due to nephro-ureteral obstruction. Conversely, women with non-lateralizing abdominal or back pain have a statistically significant likelihood of negative renal CT scan. CLINICAL RELEVANCE/APPLICATION Clinical predictors for positive renal CT scans would aid clinicians to more selectively order a renal CT scan minimizing radiation risk to those that have a low likelihood of a positive result. ER221-SDTUA4 Image Quality and Dose Reduction of CT Pulmonary Angiogram with 100 kVp and Iterative Reconstruction to Detect Pulmonary Embolism in Emergency Room Patients Station #4 Awards Trainee Research Prize - Resident Participants Edward Kuoy, MD, Orange, CA (Presenter) Nothing to Disclose Jeanie C. Zhang, MD, Orange, CA (Abstract Co-Author) Nothing to Disclose Phillip Reich, MD, Orange, CA (Abstract Co-Author) Nothing to Disclose Thangavijayan Bosemani, MBBS, MD, Orange, CA (Abstract Co-Author) Nothing to Disclose Pablo J. Abbona, MD, Orange, CA (Abstract Co-Author) Nothing to Disclose Mayil S. Krishnam, MBBS, MRCP, Orange, CA (Abstract Co-Author) Nothing to Disclose PURPOSE To assess image quality (IQ) and dose savings of CTPA for detecting pulmonary embolism (PE) in patients with 100kVp and iterative reconstruction(IR) and to compare results with 120kVp and filtered back projection(FBP). METHOD AND MATERIALS CTPA performed on 256-slice scanner for 96 consecutive ER patients with suspected PE using 100kVp protocol with adaptive IR (iDose3) (Group A), and 28 consecutive patients previously imaged for PE with 120kVp and FBP (Group B), stratified by BMI of 25, were evaluated for dose length product (DLP), volume CT dose index (CTDIv) and effective dose(ED). Arterial contrast density (Hounsfield Units,HU), contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of 27 pulmonary artery(PA) segments were calculated per patient. Two experienced radiologists independently assessed PA segments for IQ, noise, motion artifacts (MA) and PE. RESULTS The median CTDIv in Group A vs B with BMI<25: 6(IQR 5-7) and 10(IQR 9-13) mGy, respectively, and BMI>25: 9(IQR 7-13) and 17(IQR 13-20) mGy, respectively. Median DLP in Group A vs B with BMI<25: 227(IQR 178-283) and 366(IQR 303-486) mGy•cm, respectively, and BMI>25: 320(IQR 271-448) and 685(IQR 520-824) mGy•cm, respectively. ED in Group A vs B with BMI<25: 3(IQR 2-4) & 5(IQR 4-7) mSv, respectively (40% reduction), and BMI>25: 4(IQR 4-6) & 10(IQR 7-12) mSv, respectively (60% reduction). CNR and SNR were lower in Group A than B across BMI (p<0.01). Median arterial HU in Group A vs B with BMI<25: 438(IQR 320-519) & 310(IQR 249-451) HU, respectively, and BMI>25: 359(IQR 301-447) & 285(IQR 230-348) HU, respectively (both p<0.01). Overall IQ was statistically better in Group A than B with BMI<25, but vice versa for BMI>25 (p<0.01) with good inter-observer agreement (K>0.6). Minimal subjective noise without affecting diagnostic contents was more in Group A than B across BMI (p<0.01, K>0.6). There was no difference in MA between groups (p>0.05, moderate K>0.5). Acute segmental and subsegmental PEs (3) and findings of pulmonary infarcts, nodules and adenopathy were noted in Group A. CONCLUSION CTPA with 100kVp and IR results in significant dose reduction and provides improved arterial attenuation with sufficient CNR and SNR to reliably detect PE in patients with BMI<25. CLINICAL RELEVANCE/APPLICATION CTPA with 100kVp and IR can be employed in patients with BMI<25 to achieve significant dose reduction, while also preserving diagnostic ability for assessment of PE. ER178-EDTUA6 Blunt Traumatic Vascular Injuries of the Neck in the ED: What the Radiologist Must Know Station #6 Awards Identified for RadioGraphics Participants Elizabeth George, MD, Boston, MA (Presenter) Nothing to Disclose Ashish R. Khandelwal, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christopher A. Potter, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG Srinivasan Mukundan, MD, PhD, Boston, MA (Abstract Co-Author) Institutional research support, Siemens AG Institutional research support, Toshiba Corporation Consultant, Toshiba Corporation Bharti Khurana, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Diego B. Nunez JR, MD, MPH, Boston, MA (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1. Blunt trauma to the neck is associated with distinct patterns of vascular injuries. These include intramural hematoma, dissection, pseudoaneurysm, occlusion, transection and fistula.2. The mechanism of trauma, associated fractures and soft tissue injuries can be indicative of the likelihood and nature of vascular injury.3. Increased use of screening CTA in high-risk trauma patients has resulted in increased detection of these injuries. It is essential that radiologists are cognizant of the evidence for the screening criteria for CTA and understand the imaging features, grading, and management of such vascular injuries. TABLE OF CONTENTS/OUTLINE 1. Evidence for screening criteria for the initial evaluation of patients with suspected cerebrovascular injury.2. Systematic approach to CTA interpretation in trauma patients.3. Imaging features of vascular injuries of the neck, including the vertebral and carotid arterial system and the grades of blunt cerebrovascular injury.4. Review the mechanism of injury by analyzing the associated fractures and soft tissue injuries. The basic mechanisms, such as shearing from flexion/extension/rotational injury and direct trauma from fracture fragments will be discussed.5. Describe current management strategies, specifically anticoagulation and the limited indications for intervention. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator Bharti Khurana, MD - 2014 Honored Educator ERS-TUB Emergency Radiology Tuesday Poster Discussions Tuesday, Nov. 29 12:45PM - 1:15PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Jamlik-Omari Johnson, MD, Atlanta, GA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press Martin L. Gunn, MBChB, Seattle, WA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press; Spouse, Consultant, Reed Elsevier; Spouse, Consultant, athenahealth, Inc; ; Sub-Events ER223-SDTUB1 Perisiplenic Hematoma Volume Calculation with a New Formula Confirmed with Semi-Automated Method Station #1 Participants Uygar Teomete, MD, Coral Gables, FL (Presenter) Nothing to Disclose Tuncer Ergin, MD, Ankara, Turkey (Abstract Co-Author) Nothing to Disclose Ozgur Dandin, MD, Bursa, Turkey (Abstract Co-Author) Nothing to Disclose Onur Osman, PhD, Istanbul, Turkey (Abstract Co-Author) Nothing to Disclose Ferhat Cuce, MD, PhD, Van, Turkey (Abstract Co-Author) Nothing to Disclose Gokalp Tulum, Istanbul, Turkey (Abstract Co-Author) Nothing to Disclose Adlan Olsun, Istanbul, Turkey (Abstract Co-Author) Nothing to Disclose PURPOSE The correct calculation of intraperitoneal hematoma is vital for the management of patients who have trauma. Our aim is to present a new formula for calculating perisplenic hematoma due to abdominal trauma comparing to the conventional method. METHOD AND MATERIALS Data of the patients who had traumatic spleen injuries were evaluated from the database of trauma registry. Randomly selected 25 CT scans from 25 patients with traumatic perisplenic hematomas were studied. We developed a semi-automated system calculating the perisplenic hematoma volumes in trauma patients utilized as the reference standard. By two radiologists, the calculations were performed by using conventional formula, trilinear formula, direct method and semiautomatic computer-aided method. Finally, the results were compared. Total volume (spleen+ hematoma) was provided by using the W1T1L1/2 formula in the conventional method. The spleen volume was obtained as 0.36(W2T2L2)+28. The total volume was provided as total volume minus spleen volume. We proposed trilinear approximation functions as total volume=13.96W1-3.20T1-0.44L1-0.067W1T10.13W1L1+0.0417T1L1+9.66x10-4W1T1L1, spleen volume==6.055W2+1.75T2-2.76L2-0.119W2T20.0154W2L2+0.0255T2L2+8.82x10-4W2T2L2. The hematoma volume was provided by the subtracting of spleen volume from total volume. With direct method, the hematoma volume was calculated as hematoma volume=3.713W1+5.834W20.606T1+0.503T2+1.52L1-4.257L2+0.016W1T1-0.128W2T2 -0.0691W1L1+0.015W2L2+0.006T1L1+0.0326T2L2+5.51 x104W1T1L1-4.89x10-4W2T2L2 where W,T, L are width, thickness and length.All co-efficient were obtained by least squares method which minimize the error. RESULTS The root mean square error of hematoma volume for, the conventional method, trilinear and direct method were 78.54, 67.60 and 24.07 mL, respectively. CONCLUSION The volume of perisplenic hematoma calculation was feasible for all cases. Our new formula created with direct method had high accuracy rate comparing the conventional method. This new formula considered to has an important role in the management of patients who have perisplenic hematoma due to trauma. CLINICAL RELEVANCE/APPLICATION The correct and rapid calculation of perisplenic hematoma volume with our new formula and semiautomatic methods will help to clinicians by affecting the management and outcome of the patients who have abdominal trauma. ER224-SDTUB2 Perinephric Fat Stranding on Abdominal CT in Adult Emergency Department Patients: What Are The Clinical Implications? Station #2 Participants Erin N. Gomez, MD, Columbia, MD (Abstract Co-Author) Nothing to Disclose Susan Lin, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Elliot K. Fishman, MD, Baltimore, MD (Abstract Co-Author) Institutional Grant support, Siemens AG; Institutional Grant support, General Electric Company; Linda Regan, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Amit Pahwa, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Pamela T. Johnson, MD, Baltimore, MD (Presenter) Consultant, National Decision Support Company PURPOSE Perinephric fat stranding (PFS) is a common finding on abdominal CT. Practitioners have voiced uncertainty regarding the clinical significance of patients with PFS on CT and whether it is an indicator of urinary tract infection (UTI). The purpose of this study is to determine the frequency of UTI and define an evidence-based management algorithm for adult emergency department patients with PFS on CT. METHOD AND MATERIALS CT reports of adult patients imaged in the ED were retrospectively searched to identify “perinephric stranding” in the dictated report. Medical records of 166 subjects imaged between 2013 and 2015 were reviewed for clinical presentation, laboratory and culture data, CT findings, medical diagnosis and management.Criteria for clinical diagnoses were defined as follows: Uncomplicated cystitis: asymptomatic pyuria UTI: symptomatic pyuria Pyelonephritis: symptomatic pyuria + fever OR flank pain elevated WBC + fever + flank pain Statistical analysis was performed using Microsoft Excel and Stata version 14. RESULTS Preliminary data includes 93 male and 73 female subjects with average age of 53 years (range 20-88 years).The most common additional CT finding reported in subjects with PFS was obstructing stone (72/166, 43%). These subjects were removed from further evaluation. Of the 94 patients without an obstructing stone, 17% (16/94) met criteria for UTI and 12% (11/94) met criteria for pyelonephritis. Of the 91 patients without an obstructing stone who had urinalysis, 70% (64/91) had pyruia, but 52% (47/91) had asymptomatic pyuria. Additional analyses of the imaging and clinical findings for the entire cohort of 300 subjects will be used to generate a management algorithm defining which patients with PFS should be treated for urinary tract infection. CONCLUSION Most adult emergency department patients in this cohort with perinephric stranding on abdominal CT had pyuria, but it was asymptomatic in the majority of cases. Clinical criteria for UTI and pyelonephritis were met in < 30% and should be heavily weighted in management decision making. CLINICAL RELEVANCE/APPLICATION Practitioners and radiologists must recognize that perinephric fat stranding, even in patients with pyuria, does not necessarity indicate the presence of a clinically significant urinary tract infection. Evidence based management algorithms are warranted to define which patients require treatment. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Pamela T. Johnson, MD - 2016 Honored Educator Elliot K. Fishman, MD - 2012 Honored Educator Elliot K. Fishman, MD - 2014 Honored Educator Elliot K. Fishman, MD - 2016 Honored Educator ER225-SDTUB3 Non-contrast MDCT for Ureteral Calculi and Alternative Diagnoses: Yield in Adult Women versus in Adult Men Station #3 Awards Student Travel Stipend Award Participants Parisa Fani, MD, Hamilton, ON (Presenter) Nothing to Disclose Michael N. Patlas, MD, FRCPC, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Sandra Monteiro, PhD, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose PURPOSE To determine the yield of non-contrast CT(NCCT) for the diagnosis of ureteral calculi and alternative diagnoses in adult men versus adult women presenting with suspected renal colic to the emergency department (ED) of a teaching hospital. METHOD AND MATERIALS Our IRB-approved a retrospective review of the non-contrast CT scans of the abdomen and pelvis (APNCCT) performed on adult patients (18 years and older) presenting to a single emergency department with acute flank pain over a 25-month period. Patients with known obstructive ureteral calculi, or with known urinary tract infection, malignancy, or trauma, prior to CT, were all excluded. We compared the prevalence of ureteral calculi and alternative diagnoses between the men and the women, based on review of the images. P values and Confidence Intervals (CI) were determined using the chi-square test. RESULTS One attending radiologist and one radiology resident randomly selected (using a number generator) and reviewed 400 scans from a total of 1097 APNCCT examinations performed from October 1, 2011, to October 30, 2013, at our institution (representing approximately 1/3 of the examinations). The mean patient age was 55.2 years, with a range of 19 to 90 years. This included 170 women (mean age 56.8 years), and 230 men (mean age 54.2 years). Ureteral calculi were observed in 42.5% of all patients, including in 111 men (48%) and 59 women (34.7%). The prevalence of ureteral calculi in men was significantly higher than in women (p<0.01, Confidence Level of 95%, and CI of 13.3). Alternative diagnoses were demonstrated on APNCCT in 12.5% of patients, including 23 in men (5.7%) and 27 in women (6.7%). Alternative diagnoses in women included ovarian cyst (n=1), ovarian torsion (n=1), and degeneration of a uterine fibroid (n=1).There was no statistically significant difference in the overall prevalence of alternative diagnoses between men and women (p>0.2). CONCLUSION Based on our single-institution retrospective review of a subset of adult patients, the likelihood of a ureteral calculus being present Based on our single-institution retrospective review of a subset of adult patients, the likelihood of a ureteral calculus being present on APNCCT performed for suspected renal colic was significantly higher in men compared with in women. CLINICAL RELEVANCE/APPLICATION APNCCT had a lower yield in women presenting to a single teaching hospital’s ED with suspected renal colic, compared with in men, although the alternative diagnosis rate was not statistically different. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator ER227-SDTUB5 The Feasibility of Dual Energy Computed Tomography in Cardiac Contusion Imaging Station #5 Awards Student Travel Stipend Award Participants Recep Sade, MD, Erzurum, Turkey (Presenter) Nothing to Disclose Mecit Kantarci, MD, PhD, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose Hayri Ogul, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose Ummugulsum Bayraktutan, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose Mustafa Uzkeser, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose Sahin Aslan, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose Enbiya Aksakal, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose Necip Becit, Erzurum, Turkey (Abstract Co-Author) Nothing to Disclose PURPOSE The purpose of this study is the evaluation of the efficiency and feasibility of DECT use in the diagnosis of cardiac contusion with the mildest blunt cardiac injury (BCI) METHOD AND MATERIALS From February 2014 to September 2015, a total of 17 consecutive patients (10 men and 7 women; median age 51 years [20-78]) were enrolled in the study. DECT was performed within 48 hours of the trauma and a subsequent control DECT was performed a little less than one year after the first examination. All examinations were analyzed on iodine map images by two experienced radiologists. Interobserver agreement was calculated. RESULTS The contusion areas were amorphous, with considerable variation in their size, shape, and density. Contusions were primarily located in the left ventricle’s free wall, the ventricular septum, and the apex, respectively. In 10 patients, contusion areas disappeared upon control examination. In four patients, the contusion areas decreased but were still present in the control examination. The interobserver agreements were almost perfect with respect to the presence of cardiac contusion, the anatomic location of contusions, and the contusion areas (kappa values of 1.0, 1.0, and 0.9, respectively). CONCLUSION DECT can show cardiac contusion and can be usable and feasible for the diagnosis and follow-up study in BCIs. DECT is a very new, user-independent and valuable imaging technique CLINICAL RELEVANCE/APPLICATION DECT can show cardiac contusion and can be usable and feasible for the diagnosis and follow-up study in BCIs. SSJ06 Emergency Radiology (Dual Energy CT) Tuesday, Nov. 29 3:00PM - 4:00PM Room: N227B CT ER AMA PRA Category 1 Credit ™: 1.00 ARRT Category A+ Credit: 1.00 FDA Discussions may include off-label uses. Participants Martin L. Gunn, MBChB, Seattle, WA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press; Spouse, Consultant, Reed Elsevier; Spouse, Consultant, athenahealth, Inc; ; Aaron D. Sodickson, MD, PhD, Boston, MA (Moderator) Research Grant, Siemens AG; Consultant, Bayer AG Sub-Events SSJ06-01 Role of a Novel Material Decomposition Algorithm in Detection of Acute Infarction Tuesday, Nov. 29 3:00PM - 3:10PM Room: N227B Awards Student Travel Stipend Award Participants Mohammed F. Mohammed, MBBS, Vancouver, BC (Presenter) Nothing to Disclose Faisal Khosa, FFR(RCSI), FRCPC, Atlanta, GA (Abstract Co-Author) Nothing to Disclose David J. Ferguson, MBBCh, FRCR, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Reem S. Zakzouk, MD, Riyadh, Saudi Arabia (Abstract Co-Author) Nothing to Disclose Olivia Marais, BEng, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Tim O'Connell, MD, Meng, Vancouver, BC (Abstract Co-Author) President, Resolve Radiologic Ltd Speake, Siemens AG Heiko Schmiedeskamp, PhD, Malvern, PA (Abstract Co-Author) Employee, Siemens AG Bernhard Krauss, PhD, Forchheim, Germany (Abstract Co-Author) Employee, Siemens AG Michael E. O'Keeffe, MBBCh, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG Axel C. Rohr, MD, Kiel, Germany (Abstract Co-Author) Nothing to Disclose Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG PURPOSE The role of the non-enhanced CT in the setting of acute stroke has always been that of a quick rule-out tool to exclude haemorrhage, with low accuracy in detecting acute infarcts and reported accuracy of 61%.DECT with material decomposition (MD) has shown promise in post post intra-arterial revascularization. We present a novel material decomposition algorithm which improves detection of acute infarcts on non-enhanced DECT by subtracting grey and white matter, accentuating cytotoxic edema. METHOD AND MATERIALS A retrospective study was conducted on consecutive patients that presented to the Emergency Department (ED) at our institution between January, 2016 and March, 2016, with clinical suspicion of stroke within the last 4 hours and underwent non-enhanced Dual Energy CT (DECT) of the head (N = 26). Informed consent was waived for this retrospective study. Follow up CT, MRI or catheter angiography served as the reference standard.DECT images were acquired on a 3rd generation Dual Source DECT scanner at 100 kV and 150 kV. Material decomposition (MD) images were reconstructed on the Syngo.Via platform, allowing subtraction of Grey Matter (GM) from White Matter (WM).The images were reviewed by 2 neuroradiology fellowship trained radiologists, blinded to outcomes, and independently rated concordance of 120 kV images and MD images with the reference standard. RESULTS 15 of 26(57.7 %) patients presented with confirmed acute infarcts. 120 kV images had a sensitivity, specificity, PPV and NPV of 80% (95% CI = 51.9%-95.7%), 72.7% (95% CI = 39%-94%), 80% (95% CI = 51.9%-95.7%) and 72.73% (95% CI 51.91%-95.67%) respectively.MD images provided greater sensitivity, specificity, PPV and NPV of 93.33% (95% CI = 68.05%-99.83%), 100% (95% CI = 71.51%-100%), 100% (95% CI = 76.84%-100%) and 91.67% (95% CI = 61.52%-99.79%) respectively when assessed in conjunction with the conventional images. MD images improved confidence by 30.77% and were found useful in 85% of studies. CONCLUSION Head DECT with MD images reconstructed to subtract GM from WM improve the PPV and NPV of non-enhanced CT in the setting of acute infarction, up to 100% and 91.67% respectively while boosting confidence by 30.77% when read in conjugation with conventional 120 kV blended images. CLINICAL RELEVANCE/APPLICATION MD images provide a novel tool in assessment of acute stroke on the non-enhanced CT of the head. SSJ06-02 Advanced Virtual Monoenergetic Imaging in Low-dose Dual-energy Unenhanced Head CT: Evaluation of Image Quality, Delineation of Intracranial Hemorrhage and Radiation Exposure Tuesday, Nov. 29 3:10PM - 3:20PM Room: N227B Participants Christoph Polkowski, MD, Frankfurt, Germany (Presenter) Nothing to Disclose Moritz Kaup, Frankfurt, Germany (Abstract Co-Author) Nothing to Disclose Doris Leithner, MD, Frankfurt am Main, Germany (Abstract Co-Author) Nothing to Disclose Moritz H. Albrecht, MD, Charleston, SC (Abstract Co-Author) Nothing to Disclose Julian L. Wichmann, MD, Charleston, SC (Abstract Co-Author) Nothing to Disclose Claudia Frellesen, Frankfurt, Germany (Abstract Co-Author) Nothing to Disclose Thomas J. Vogl, MD, PhD, Frankfurt, Germany (Abstract Co-Author) Nothing to Disclose Jan-Erik Scholtz, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate quantitative image quality parameters of advanced monoenergetic imaging algorithm (VMI+) in low-tube-current dualenergy unenhanced head CT and diagnostic accuracy for the detection of intracranial hemorrhage (ICH) compared to standard 120kVp. METHOD AND MATERIALS In this retrospective IRB-approved study with a waiver for written consent, 94 patients underwent unenhanced head CT to detect or rule out ICH on a third-generation dual-source CT. Standard 120-kVp CT (n=44; CTDIvol, 39.5±0.4mGy) was compared with lowtube-current dual-energy CT (DECT, 80/140-kVp; n=50, CTDIvol, 23.7±2.7mGy) with post-processing VMI+ algorithm. Gray matter (GM) signal-to-noise ratio (SNR), white matter (WM) SNR, GM-WM contrast-to-noise ratio (CNR), ICH-GM CNR, and posterior fossa artifact index (PFAI) were calculated. Measurements in VMI+ were performed at energy levels from 40-190-keV with 5-keV increment. Image series with highest GM-WM CNR and ICH-GM CNR in VMI+ were reconstructed for subjective image analysis. Three radiologists performed diagnostic evaluation for ICH for both protocols, “gold standard” for ICH evaluation was the medical report. RESULTS GM SNR (18.5±3.5 vs. 11.7±1.9) and WM SNR (15.5±2.5 vs. 8.2±1.2) were significantly better at 110-keV VMI+ compared to 120kVp. GM-WM CNR was highest at 40-keV with no significant difference compared to 120-kVp (2.3±0.6 vs 2.2±0.6). ICH-GM CNR was significantly higher in 140-keV compared to 120-kVp (7.7±3.7 vs. 3.4±2.7, p<0.001). 110-keV VMI+ showed slightly, but not significantly lower values for ICH-GM CNR compared to 140-keV. PFAI was significantly lower at 110-keV compared to 120-kVp (2.1±0.3 vs 4.9±0.5HU, p<0.001). All examinations were sufficient for evaluation of ICH in 120-kVp and 110-keV VMI+ with no nondiagnostic cases. 40-keV VMI+ with best values for GM-WM CNR was inadequate for evaluation of ICH non-diagnostic to poor ratings. Diagnostic accuracy for detection of ICH was excellent in both 110-keV VMI+ (n=14) and 120-kVp (n=11) with no significant difference and almost perfect interobserver agreement (ICC, 0.88). CONCLUSION 110-keV VMI+ low-dose dual-energy unenhanced head CT provides increased CNR between ICH and GM with excellent diagnostic accuracy of ICH while radiation dose is significantly reduced compared to 120-kVp. CLINICAL RELEVANCE/APPLICATION 110-keV VMI+ allows low-dose unenhanced head dual-energy CT with superior ICH to GM contrast compared to 120-kVp. SSJ06-03 The Dual Energy Hot Gallbladder and Rim Signs: Evaluation of DECT Iodine Content in Acute Cholecystitis Tuesday, Nov. 29 3:20PM - 3:30PM Room: N227B Participants Jennifer W. Uyeda, MD, Boston, MA (Presenter) Nothing to Disclose Tony W. Trinh, MD, Salt Lake City, UT (Abstract Co-Author) Nothing to Disclose Jeremy R. Wortman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Aaron D. Sodickson, MD, PhD, Boston, MA (Abstract Co-Author) Research Grant, Siemens AG; Consultant, Bayer AG PURPOSE ED patients often undergo abdominal CT as the initial imaging examination for nonspecific abdominal pain. The purpose of this study was to assess differences in the dual energy CT (DECT) iodine content of pericholecystic hepatic parenchyma and of the gallbladder wall in acute cholecystitis compared with controls. METHOD AND MATERIALS 17 patients (10M, 7F) who underwent cholecystectomy with pathology confirmed acute cholecystitis were included in this IRB approved, HIPAA compliant study. All patients underwent contrast enhanced DECT on a dual-source 128x2 slice scanner (Siemens FLASH) with either 80/Sn140 or 100/Sn140 kV pairs depending on patient size. Within 3 mm reconstructed slices, the following regions of interest (ROI) were placed on iodine overlay images to measure dual energy iodine concentration derived from three material decomposition: 1 cm2 hepatic parenchyma around the gallbladder fossa, 1 cm2 hepatic parenchyma in a different hepatic segment, and 5 mm2 on the gallbladder wall. These values were normalized to the iodine concentration in a main portal vein ROI to calculate a normalized iodine concentration. Measurements were compared to 20 control patients who underwent DECT without gallbladder pathology. Normalized iodine content in each of the three ROI locations was compared between the two groups using a t-test. RESULTS There was no significant difference between cholecystitis and control patients in normalized iodine content within the hepatic parenchyma remote from the gallbladder fossa (p=0.72). However, compared with controls, acute cholecystitis patients demonstrated higher normalized iodine concentration values within the hepatic parenchyma of the gallbladder fossa and within the gallbladder wall (p<0.001 for both comparisons). CONCLUSION DECT can detect increased pericholecystic hepatic parenchymal and gallbladder wall iodine content in patients with acute cholecystitis. Further work is needed to determine appropriate threshold values of iodine content that may aid in the diagnosis of acute cholecystitis. CLINICAL RELEVANCE/APPLICATION Cholecystitis patients demonstrate increased iodine content within the gallbladder wall and pericholecystic hepatic parenchyma by Dual Energy CT. This may prove helpful in improving CT diagnosis of acute cholecystitis. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Aaron D. Sodickson, MD, PhD - 2014 Honored Educator SSJ06-04 Detection of Isodense Gallstones using Monoenergetic Dual Energy CT: Evaluation of Stone Size Thresholds Tuesday, Nov. 29 3:30PM - 3:40PM Room: N227B Awards Student Travel Stipend Award Participants Jun Wang, MD, Vancouver, BC (Presenter) Nothing to Disclose Yuhao Wu, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Faisal Khosa, FFR(RCSI), FRCPC, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG Tim O'Connell, MD, Meng, Vancouver, BC (Abstract Co-Author) President, Resolve Radiologic Ltd Speake, Siemens AG Luck J. Louis, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG PURPOSE To establish the size threshold for identifying previously undetectable isodense gallstones using monoenergeticDual Energy CT (DECT) METHOD AND MATERIALS A retrospective review was performed on 3464 consecutive DECT scans of the abdomen acquired using a dual-source 128-slice CT (Definition FLASH; Siemens Healthcare, Forcheim, Germany) between the dates January 2013-June 2015. These patients were cross-referenced using our Picture Archival and Communication System (Impax; Agfa Healthcare, Mortsel, Belgium) to select those who had undergone an ultrasound of the gallbladder, MRCP or ERCP within six weeks of the DECT scan. Inclusion criteria were patients who had a DECT scan that did not demonstrate cholelithiasis, but a subsequent investigation (US, MRCP, or ERCP) that did demonstrate gallstones. Monoenergetic reconstructions were then performed at 40 keV and 190 keV using the DECT raw data from these patients with gallstone disease that was missed on conventional CT. Overall sensitivity for using monoenergetic reconstructions to detect isodense gallstones was calculated. Attenuation measurements were made using 1cm2 regions of interest in the gallbladder as well as the gallstones at 190 kev and 40 kev. RESULTS Monoenergetic reconstructions at 40 keV and 190 keV were performed on a total of 31 patients who fit the inclusion criteria and reviewed for the presence of gallstones. Eight patients had identifiable gallstones. Using a size threshold of <10mm, the sensitivity of monoenergetic imaging to detect previously missed isodense gallstones was 25.8%. When a threshold size of >10mm was used, the sensitivity of monoenergetic reconstructions to identify previously missed isodense gallstones increased to 88.9%. ROI measurements of the gallbladder at 190 keV (mean attenuation 7.77±5.80 HU) were significantly different from gallstone ROI attenuation (44.9±14.5 HU, p<0.001.). ROI measurements of the gallstones and gallbladder at 40 keV did not differ significantly (3.70±47.6 HU vs. 23.9±22.5 HU). CONCLUSION Monoenergetic dual energy CT acquisitions of the abdomen at 190 keV can identify gallstones that appear iso-dense on conventional CT with a sensitivity of 88.9% at a size threshold of 10mm. CLINICAL RELEVANCE/APPLICATION The use of monoenergetic dual energy CT imaging allows identification of previously undetectable isodense gallstones at a size threshold of 10mm and improves the sensitivity of CT in the investigation of gallstone disease. SSJ06-05 Improved Signal and Image Quality at the Cervicothoracic Junction Utilizing Third Generation Dual Source CT Technology Tuesday, Nov. 29 3:40PM - 3:50PM Room: N227B Participants Sudha R. Muly, MBBS, FRCR, Vancouver, BC (Presenter) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG Luck J. Louis, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Tim O'Connell, MD, Meng, Vancouver, BC (Abstract Co-Author) President, Resolve Radiologic Ltd Speake, Siemens AG Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG Faisal Khosa, FFR(RCSI), FRCPC, Atlanta, GA (Abstract Co-Author) Nothing to Disclose Nizar Bhulani, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose Heiko Schmiedeskamp, PhD, Malvern, PA (Abstract Co-Author) Employee, Siemens AG Bernhard Krauss, PhD, Forchheim, Germany (Abstract Co-Author) Employee, Siemens AG PURPOSE Evaluation of the cervicothoracic junction is frequently limited by beam hardening and scatter radiation artifacts. Previous studies have shown the usage of dual energy CT (DECT) to reduce this artifact and improve image quality utilizing Monoenergetic algorithm (Mono +). The purpose of our study is to determine if the artifacts at the cervicothoracic junction can be further reduced and image quality can be improved using the third generation dual source CT scanner. METHOD AND MATERIALS In this retrospective study, 20 consecutive trauma patients who underwent cervical spine DECT using a third generation dual source CT scanner (Definition FORCE, Siemens Health care, Germany) between February to April 2016. The DECT data sets (100 and 150 sn kv) were reconstructed using Mono + algorithm at energy levels ranging from 70 to 190 Kev. Attenuation of the spinal cord at each energy level was compared to the values on the simulated 120kv scan images obtained from the mixed DECT data sets. Subjective analysis of image quality was conducted on a semi-objective 4 point scoring scheme by 2 radiologists. RESULTS Our data demonstrates reduction of noise on the images of 110-130keV range, when compared to the mixed data set images of 120 kvp. We found that the optimal energy level for reduction of artifacts and noise is around 130Kev. The attenuation values of the spinal cord at C2 and at the cervico-thoracic level are most stable between 110 and 130Kev reconstruction. Semi-quantitative analysis showed improvement of visualization of the soft tissue structures at 130Kev (p value of 0.002). The diagnostic confidence of the reader in identifying bone and soft tissue abnormality at the cervico-thoracic junction was significantly increased at the higher energy levels 130 Kev (p value 0.001 compared to 70 Kev CONCLUSION DECT assessment using Mono + algorithm shows significantly reduced artifact at the cervicothoracic junction with increased reader confidence of assessing structures. Our study demonstrates that reconstruction of images on mono+ at energy levels closer to 130 Kev provide the best image quality with reduced beam hardening artifact reduction and noise levels. CLINICAL RELEVANCE/APPLICATION Due to its superior image quality, third generation dual source CT images using Mono + algorithm can provide a significant benefit by reducing artifact and improving assessment of cervicothoracic junction without increasing the radiation dose. RC405 Emergency Neuroradiology (An Interactive Session) Tuesday, Nov. 29 4:30PM - 6:00PM Room: S406B NR ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 FDA Discussions may include off-label uses. Participants Michael H. Lev, MD, Boston, MA (Moderator) Consulant, General Electric Company; Institutional Research Support, General Electric Company; Stockholder, General Electric Company; Consultant, MedyMatch Technology, Ltd; Consultant, Takeda Pharmaceutical Company Limited; Consultant, D-Pharm Ltd Sub-Events RC405A Found Down Participants John L. Go, MD, Los Angeles, CA (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Choose the best imaging for each patient. 2) Discuss the Differential Dx for “found down”. 3) Develop a “checklist” for imaging to identify significant findings. 4) Recognize imaging findings that will acutely change patient management. ABSTRACT The "found down" patient is unable to provide a history - and often unable to cooperate for a clinical exam. Up to 1/3 are mistriaged and require consultation to another service. Common "medical" conditions include: Hypoxia/Hypotension, Subarachnoid Hemorrhage Hypoglycemia/Hyperglycemia Drugs and Intoxicants Post-ictalCommon "surgical" conditions include: Extraaxial and Intraaxial Hemorrhage Hydrocephalus Herniation (e.g. from a neoplasm) Large Vessel Occlusion and InfarctionA systematic analysis using a "checklist" can help identify life-threatening lesions and may be life-saving. RC405B Head & Neck Emergencies Participants Jenny K. Hoang, MBBS, Durham, NC (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Develop a systematic approach to evaluating patients with head and neck infections. 2) Recognize head and neck emergencies that result in morbidity and mortality presenting as fever, trauma, difficulty breathing, and bleeding. RC405C Emergency Neuroradiology: Don't Miss these Lesions! Participants Michael H. Lev, MD, Boston, MA (Presenter) Consulant, General Electric Company; Institutional Research Support, General Electric Company; Stockholder, General Electric Company; Consultant, MedyMatch Technology, Ltd; Consultant, Takeda Pharmaceutical Company Limited; Consultant, D-Pharm Ltd LEARNING OBJECTIVES 1) Summarize the role of imaging in the assessment of acute neurologic emergencies. 2) Apply an evidence based approach to devise effective and efficient neuroimaging algorithms. 3) Describe technological advances in CT and MRI as they relate to imaging acute neuro-vascular and traumatic injuries to the brain. 4) Determine imaging predictors in outcome assessment of cerebral hemorrhage and acute stroke. ABSTRACT RC408 Trauma Imaging Pitfalls Tuesday, Nov. 29 4:30PM - 6:00PM Room: N228 GI MK ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Sub-Events RC408A Abdomen (Solid Organs and Vessels) Participants Felipe Munera, MD, Miami, FL, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1. Identify common pitfalls in interpretation of abdominal trauma CT studies - focus on solid organs and vascular structures. 2. Optimize CT acquisition techniques to reduce likelihood of missing potentially significant injuries. 3. Develop a search pattern that includes organs and structures where important lesions are commonly missed. 4. Describe strategies to improve detection of easily missed injuries RC408B Diaphragm Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) To describe direct and indirect signs of blunt and penetrating diaphragmatic injury. 2) To highlight factors affecting detection of diaphragmatic injury. 3) To discuss pitfalls in diagnosis of diaphragmatic injury. ABSTRACT The traumatic diaphragmatic injury is an uncommon entity. Blunt diaphragmatic injury is undiagnosed at initial presentation in 766%. Penetrating diaphragmatic injury can be occult in 7% of cases. Diaphragmatic injury does not resolve spontaneously and can cause disastrous complications. The misinterpretation in patients with diaphragmatic injury may be caused by suboptimal technique, failure to review portion of examination e.g. MPRs, or satisfaction of search error. Potential pitfalls in interpretation include congenital diaphragmatic hernias and atraumatic defects simulating diaphragmatic injury. RC408C Bowel/Pelvis Participants Stephan W. Anderson, MD, Boston, MA (Presenter) Nothing to Disclose RC408D Extremities Participants O. C. West, MD, Houston, TX (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Find upper extremity injuries that are difficult detect on screening radiographs. 2) Employ search patterns that may improve detection of easily missed injuries. ABSTRACT Summary of upper extremity pitfalls: Posterior shoulder dislocation; Supracondylar fracture (anterior humeral line); Monteggia fracture-dislocation (radio-capitellar line); Proximal radius including vertical head fracture (external oblique view), impacted neck fracture, flipped radial head fracture-dislocation, Galeazzi fracture-dislocation – beware the lateral radiograph.Imaging joints requires 3 radiographic projections. The 3rd view varies: Axillary view of shoulder and External oblique of elbow. The wrist needs 4 views: PA, lateral, external oblique and “Scaphoid” view (ulnar deviated PA view).Words to live by: watch for the least obvious of multiple injuries. Active Handout:O. Clark West http://abstract.rsna.org/uploads/2016/16000641/ACTIVE RC408D.pdf ED004-W E Emergency Radiology Wednesday Case of the Day W ednesday, Nov. 30 7:00AM - 11:59PM Room: Case of Day, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose David Dreizin, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Manickam Kumaravel, MD, FRCR, Houston, TX (Abstract Co-Author) Nothing to Disclose Constantine A. Raptis, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose David D. Bates, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thomas Battey, Timonium, MD (Abstract Co-Author) Nothing to Disclose Nicholas M. Beckmann, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose Sanjeev Bhalla, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1) Recognize key imaging findings on multimodality imaging of emergency/trauma patients. 2) Develop differential diagnosis based on the clinical information and imaging findings. 3) Recommend appropriate management including image-guided interventions. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator RC508 Emergency Radiology Series: Contemporary Topics in Imaging of Trauma W ednesday, Nov. 30 8:30AM - 12:00PM Room: S405AB ER AMA PRA Category 1 Credits ™: 3.50 ARRT Category A+ Credits: 4.00 Participants Scott D. Steenburg, MD, Zionsville, IN, ([email protected] ) (Moderator) Nothing to Disclose Clint W. Sliker, MD, Ellicott City, MD (Moderator) Nothing to Disclose Bharti Khurana, MD, Boston, MA (Moderator) Nothing to Disclose LEARNING OBJECTIVES 1) Understand the role of radiology in the setting of mass casualty scenarios. 2) Discuss the current role of imaging in the assessment of liver injuries. 3) Discuss the role of medical imaging in the setting of hip trauma. 4) Discuss the role of CT angiography for the evaluation of suspected peripheral vascular injuries. 5) Assess and evaluate current trauma radiology research and it's relevance to clinical practice. Sub-Events RC508-01 Disaster/Mass Victim Imaging W ednesday, Nov. 30 8:30AM - 9:00AM Room: S405AB Participants Ferco H. Berger, MD, Toronto, ON, ([email protected]) (Presenter) Nothing to Disclose Active Handout:Ferco H. Berger http://abstract.rsna.org/uploads/2016/16000643/RC508 01 MCI - handout.pdf LEARNING OBJECTIVES 1) Describe the setting of a mass casualty incident. 2) Develop participation of the radiology department in preparation for disaster management plan activations. 3) Explain why simmulation is crucial and recommend strategies to increase effectiveness of simulation drills. ABSTRACT In the setting of mass casualty incidents (MCI), hospitals need to divert from normal routine to delivering the best possible care to the largest number of victims. This should be accomplished by activating an established hospital Disaster Management Plan (DMP), known to all staff through prior training drills.Over the recent decades, imaging has increasingly been used to evaluate critically ill patients. It can be used as well to increase the accuracy of triaging MCI victims, since over-triage and under-triage can severely impact resource availability and mortality rates. This presentation emphasizes the importance of including the radiology department in hospital preparations for an MCI, and highlights factors expected to influence performance during hospital DMP activation including issues pertinent to effective simulation. RC508-02 Damage Control Surgery: Significance of CT Imaging in the 24 Hour Window W ednesday, Nov. 30 9:00AM - 9:10AM Room: S405AB Awards Student Travel Stipend Award Participants Armonde Baghdanian, MD, Boston, MA (Presenter) Nothing to Disclose Arthur Baghdanian, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Tina Shiang, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jorge A. Soto, MD, Boston, MA (Abstract Co-Author) Royalties, Reed Elsevier PURPOSE To retrospectively investigate the imaging findings, diagnostic accuracy, and clinical significance of CT imaging within 24 hours of Damage Control Surgery in abdominal trauma. METHOD AND MATERIALS This is a retrospective IRB approved and HIPAA compliant study. Informed consent was waived. All patients that sustained abdominal trauma and underwent immediate damage control surgery upon presentation were included if they had a diagnostic CT within 24 hours. From 3/2006-8/2013, 49 patients (46 male, 3 female; age range, 17-73 years) met our inclusion criteria. Two radiologists blinded to original radiology reports retrospectively reviewed CT examinations and recorded acute findings in consensus. A third investigator compared traumatic injuries from the original radiology reports, retrospective imaging reports, and original operative notes to determine the incidence of injuries in our patient cohort. A CT examination was categorized as missing a traumatic injury if the injury was identified on both retrospective imaging review and at surgery. In addition, an exploratory laparotomy was categorized as missing a traumatic injury if it was diagnosed on retrospective imaging review. Finally, a missed injury on either CT or surgery was categorized as clinically significant if it necessitated a repeat operation. RESULTS The etiology of trauma was blunt in 13/49 (26.5%) and penetrating in 36/49 (73.4%) patients. Overall incidence of injuries in our patient cohort included: diaphragm 6/49 (12.2%), liver 23/49 (46.9%), spleen 11/49 (22.4%), pancreas 4/49 (8.2%), bowel 38/49 (77.6%), adrenal 4/49 (8.2%), kidney 18/49 (36.7%), ureter 5/49 (10.2%), bladder 4/49 (8.2%), osseous (fracture) 34/49 (69.4%), and vascular 20/49 (40.8%). Significant CT findings were seen in 17/49 (34.7%) of which 6/17 were secondary to failed surgical repairs. 8/17 were in surgically explored areas and 9/17 were in unexplored areas. 5/17 radiology reports missed clinically significant findings found on follow up imaging or surgery. CONCLUSION Trauma patients that undergo Damage Control Surgery upon presentation have a broad spectrum of clinically significant injuries that are not diagnosed at laparotomy and therefore benefit from diagnostic CT imaging in the first 24 hours. CLINICAL RELEVANCE/APPLICATION Knowledge of surgical approaches and potential surgical and imaging pitfalls can aid in detection of injuries on MDCT in patients that undergo Damage Control Surgery. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator RC508-03 Measuring the Impact of Whole Body Computed Tomography (CT) on Emergency Department (ED) Lenghth of Stay in Blunt Trauma W ednesday, Nov. 30 9:10AM - 9:20AM Room: S405AB Awards Student Travel Stipend Award Participants Jessica Chan, MD, Salt Lake City, UT (Presenter) Nothing to Disclose Marta E. Heilbrun, MD, Salt Lake City, UT (Abstract Co-Author) Nothing to Disclose Christopher S. Johnson, Salt Lake City, UT (Abstract Co-Author) Nothing to Disclose Tom H. Greene, Salt Lake City, UT (Abstract Co-Author) Nothing to Disclose PURPOSE Whole-body CT (WBCT) imaging has become commonplace in many emergency departments (ED) in the adult blunt trauma setting, despite a growing body of research that has found no mortality or hospital length of stay (LOS) benefit for patients who received WBCT. The purpose of this study was to assess the value that WBCT imaging contributes to ED work flow, in blunt trauma patients by retrospectively comparing ED LOS between WBCT and selective CT imaging. METHOD AND MATERIALS This study is IRB approved. The Institutional Trauma Registry Database was cross-referenced with our radiology information system database to identify adult patients who sustained blunt trauma between July 2011- June 2013, and received CT imaging. Propensity score weighting was utilized to achieve balance in baseline covariates, including demographics, hemodynamic stability, Glasgow coma scale, and socio-economic factors. We generated standardized differences between imaging groups both before and after propensity-score weighting to assess the effectiveness of our model. A linear regression with log-transformed ED length of stay was used to assess percent change in the geometric means between imaging strategies. RESULTS 2,291 patients were identified meeting inclusion criteria, of which 333 (14.5%) underwent WBCT imaging. After propensity score weighting, the arithmetic mean ED LOS was 55 ± 105 min and 83 ± 56 min for WBCT and selective CT patients respectively. Overall, there was a 21.2% (95% CI 29.4%, 11.9%) reduction in the geometric mean of ED LOS (in minutes) for those receiving whole-body scans compared to those receiving selective CT (p<0.001), after propensity score adjustment for baseline covariates. Without adjustment, we found a 38.7% (95% CI 45.3%, 31.3%) reduction in the geometric mean of ED LOS (in minutes) for those receiving WBCT compared to those receiving selective CT (p<0.001). CONCLUSION WBCT imaging was associated with a statistically and clinically significant reduction in ED LOS for blunt trauma patients. CLINICAL RELEVANCE/APPLICATION Our results suggest that WBCT in the blunt trauma setting significantly reduces ED length of stay, thus improving efficiency and workflow within the ED, and leads to downstream health care cost savings. RC508-04 The Role of Post Mortem CT in Determining Major Pathological Abnormalities Related to the Cause of Death with Autopsy Comparison W ednesday, Nov. 30 9:20AM - 9:30AM Room: S405AB Participants Yuichi Sugino, MD, Tsu, Japan (Presenter) Nothing to Disclose Hajime Sakuma, MD, Tsu, Japan (Abstract Co-Author) Departmental Research Grant, Siemens AG; Departmental Research Grant, Bayer AG; Departmental Research Grant, Guerbet SA; Departmental Research Grant, DAIICHI SANKYO Group; Departmental Research Grant, FUJIFILM Holdings Corporation; Departmental Research Grant, Nihon Medi-Physics Co, Ltd Atsuhiro Nakatsuka, MD, Tsu, Japan (Abstract Co-Author) Nothing to Disclose PURPOSE To assess the role of whole-body postmortem CT (PMCT) in determining major pathological abnormalities related to the cause of death. METHOD AND MATERIALS From September 2012 to March 2016 PMCT was performed to investigate the causes of death in 507 cases. Among them, the causes (e.g. bleeding, massive trauma, major aortic disease) in 241 cases (47.5%, 241/507) were established by PMCT and 94 cases (18.5%, 94/507) underwent autopsy because of unknown cause of death from clinical course. Fifty-five (58.5%, 55/94) cases were in-hospital death, 17 (18.1%, 17/94) cases were out-of-hospital cardiac arrest (OHCA) and 22 (23.4%, 22/94) patients were forensic cases. All cases were performed PMCT within 24 hours after death and two board-certified radiologists were evaluated the detection of cause of death comparing autopsy. RESULTS Autopsy diagnosed the cause of death including acute heart failure (n=14, 14.9%, 14/94), malignancy (n=13, 13.8%, 13/94), liver failure (n=8, 8.5%, 8/94), pneumonia (n=8, 8.5%, 8/94), trauma (n=7, 7.4%, 7/94), infection (n=5, 5.3%, 5/94), GI bleeding (n=4, 4.3%, 4/94), major vascular disease (n=2, 2.1%, 2/94), and others or unknown (n=26, 27.7%, 26/94). PMCT obtained the findings of the suspected cause of death in 43 cases (45.7%, 43/94) including 27 of 55 (49.1%) in-hospital death cases, 7 of 17 (41.1%) OHCA cases, and 9 of 22 (40.9%) forensic cases. There were no significant differences between PMCT and autopsy in detection of the cause of death among in-hospital death cases, OHCA cases, and pre forensic cases. PMCT accurately diagnosed major pathological abnormalities related to death significantly in pulmonary disorders [odds ratio (OR) = 54.5, P = 0.0016], malignancy (OR=27.8, P =0.005), liver failure (OR=14.7, P =0.015), and trauma related findings (OR=12.7, P =0.04). There were no significant differences between PMCT and autopsy in identification of cause of death in acute heart failure, major vascular disease, GI bleeding, and infection. CONCLUSION PMCT could accurately detect the cause of death in pulmonary disorders, malignancies, liver failures, and trauma related findings. CLINICAL RELEVANCE/APPLICATION PMCT provides diagnostic information about pulmonary disorders, malignancies, liver failure, and trauma related findings. RC508-05 Update on Imaging of Hepatic Injuries W ednesday, Nov. 30 9:30AM - 10:00AM Room: S405AB Participants Stuart E. Mirvis, MD, Baltimore, MD (Presenter) Nothing to Disclose LEARNING OBJECTIVES View learning objectives under the main course title. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Stuart E. Mirvis, MD - 2015 Honored Educator RC508-06 Emergency CT for Assessment and Management of Splenic Traumatic Injuries in a Level-I Trauma Center: 10-year Study W ednesday, Nov. 30 10:00AM - 10:10AM Room: S405AB Participants Sergio Margari, MD, Milan, Italy (Presenter) Nothing to Disclose Diana Artioli, MD, Milano, Italy (Abstract Co-Author) Nothing to Disclose Ettore Colombo, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Fabrizio Sammartano, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Stefania Cimbanassi, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Osvaldo Chiara, Milan, Italy (Abstract Co-Author) Nothing to Disclose Angelo Vanzulli, MD, Segrate, Italy (Abstract Co-Author) Travel support, Bracco Group PURPOSE Assessing the role of emergency CT in guiding management modality (Operative Management-OM or Non-Operative ManagementNOM) in patients with splenic traumatic injuries. METHOD AND MATERIALS We retrospectively analyzed 280 traumatic splenic injuries in 4659 patients, admitted to the emergency room of a Level-I Trauma Center from October 2002 to December 2013. Based on CT imaging, splenic injuries were classified into 5 degrees from I (the mildest) to V (the severest), according to the Organ Injury Scale (OIS) of the American Association for the Surgery of Trauma. Moreover, we considered intraparenchymal (bleed A) or extraparenchymal (bleed B) contrast blush (the active extravasation of the contrast medium in arterial phase CT scans) as an independent parameter. RESULTS We performed 202 CT scans (78 patients were excluded due to hemodynamic instability) and patients were classified on the basis of OIS degrees (29 OIS I, 46 OIS II, 87 OIS III, 35 OIS IV, 5 OIS V). Moreover, we identified 86 vascular lesions (13 pseudoaneurysms, 34 pseudoaneurysms with blush, 11 bleed A, 7 bleed B, 21 bleed A+B). There were 136 patients treated with OM (48.57%). Statistically significant predictors of OM were systolic blood pressure <90 mmHg, OIS degrees IV and V, bleed B (p<0.05). On the other hand, 144 patients underwent NOM (51.43%), all hemodynamically stable or stabilized, and with OIS ≤ III in 94.4%. NOM failed (FNOM) in 23 patients (15.97%): 2 OIS I, 4 OIS II, 16 OIS III, 1 OIS IV. FNOM occurred in 75% of cases within 30 hours from damage, without significant correlation to OIS degree and without increase of death rate. Arterial blush was predictive of FNOM (p<0.05). CONCLUSION Contrast enhanced CT scan is a useful diagnostic tool for the management of splenic traumatic injuries. CLINICAL RELEVANCE/APPLICATION CT-imaging permits an accurate assessment of splenic traumatic injuries by identifying parenchymal damage (OIS degrees) and vascular lesions (mainly arterial blush). CT scan safely influences emergency management of splenic trauma, allowing splenectomy sparing without any increase in mortality. RC508-07 Whole-Body Computed Tomography in Trauma Patients: Optimized Patient Positioning Allows a Significant Shorter Examination Time While Maintaining Image Quality W ednesday, Nov. 30 10:10AM - 10:20AM Room: S405AB Participants Tilman Hickethier, MD, Cologne, Germany (Presenter) Nothing to Disclose Kamal Mammadov, Cologne, Germany (Abstract Co-Author) Nothing to Disclose Bettina Baessler, MD, Cologne, Germany (Abstract Co-Author) Nothing to Disclose David C. Maintz, MD, Koln, Germany (Abstract Co-Author) Nothing to Disclose De-Hua Chang, Cologne, Germany (Abstract Co-Author) Nothing to Disclose PURPOSE Whole-body computed tomography (WBCT) plays a key role in the management of severely injured patients, but still no broad consensus exists regarding the ideal examination procedure. Hence, we compared examination time and artifact vulnerability of WBCTs performed either using a conventional or an optimized patient positioning. METHOD AND MATERIALS In 200 trauma patients who received a WBCT (with additional head and neck CTA (hnCTA) in 84 patients) the time from initiation of the scan to completion of the last series was measured. The presence of image artifacts in the most relevant regions was assessed using a 4-points Likert-scale (1=no artifacts, 2=minor artifacts without relevance, 3=stronger artifacts but maintained diagnostic image quality (IQ), 4= severe artifacts with non-diagnostic IQ). In 100 patients (including 41 hnCTAs) the arms were positioned alongside the body for imaging of head and neck, followed by repositioning of the arms over the head for imaging of the trunk (group “A”). In the other 100 patients (including 43 hnCTAs) the arms were flexed on a pillow anteriorly to the chest with continuous acquisition of all study regions without need for repositioning (group “B”). RESULTS The total duration of the procedure was significant shorter in “B” than in “A” for patients with hnCTA (6:55±1:54min vs. 10:54±2:04min; p<.001) and without hnCTA (6:46±1:49min vs. 10:19±2:42min; p<.001) resulting in a time saving of 3:59min or 3:33min respectively. Artifacts in aorta, liver and spleen occurred more commonly in patients from “B”, which resulted in a slight decline in IQ (mean score for lung 1.07±2.56 “A” vs. 1.02±1.41 “B”, p=0.09; aorta 1.07±2.93 vs. 1.27±4.46, p<.001; liver 1.09±3.21 vs. 1.43±5.55, p<.001; spleen 1.05±2.19 vs. 1.20±4.49, p<.001). No artifacts were observed in the spine and there was no examination with nondiagnostic IQ. Random forests and logistic regression analyses showed that the increase in artifacts was not only due to the optimized positioning itself but also to amendable causes (foreign objects/positioning faults). CONCLUSION The continuous acquisition of all study regions by using an optimized positioning protocol for WBCT in trauma patients allows reducing the examination time by more than 30% while maintaining diagnostic image quality. CLINICAL RELEVANCE/APPLICATION A significant reduction in examination time allows a faster diagnosis of severely injured patients and a smoother workflow for the involved medical employees. RC508-08 Low-Dose CT with the Adaptive Statistical Iterative Reconstruction (ASIR)-V Technique in Abdominal Organ Injury Grading: Comparison with Routine-Dose CT with Filtered Back Projection (FBP) W ednesday, Nov. 30 10:20AM - 10:30AM Room: S405AB Participants Nam Kyung Lee, MD, Busan, Korea, Republic Of (Presenter) Nothing to Disclose Jeongmyeong Kim, MD, Pusan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Suk Kim, MD, Pusan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Seung Hyun Lee, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Ga Jin Han, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose PURPOSE Whole-body multidetector CT examination has been proposed to evaluate patient who has sustained multisystem trauma. However, whole-body exposure leads to an increase in radiation dose. Most recently, a novel iterative reconstruction technique, ASIR-V has potential for significant dose reduction with better image quality than conventional ASIR, at real time speed. Thus, the purpose is to evaluate American association for the surgery of trauma (AAST) abdominal organ injury grading in low-dose CT with ASIR-V, in comparsion with routine-dose CT with FBP. METHOD AND MATERIALS Eighty-three trauma patients underwent both routine-dose CT using FBP and low-dose CT using ASIR-V in the abdomen. Two readers reviewed the presence, absence, and the grading of abdominal organ injuries (liver, kidney, spleen or pancreas) using AAST scales. CT detection rates of abdominal organ injury, and AAST grading were compared between two different CT protocols, using McNemar test. Additionally, objective image noise was compared between two CT protocols, using paired t-test. RESULTS The radiation dose for low-dose CT with ASIR-V was 3.4 mSv, in comparison with 8.8 mSv for routine-dose CT with FBP. Abdominal organ injury was detected in 33 organs of 21 patients on routine-dose CT with FBP, and 29 organs in 20 patients on low-dose CT with ASIR-V. The detection rate was not significantly different between two different protocols (p > 0.05). The diagnostic performance of the AAST grading was also not significantly different between two different protocols (p > 0.05). Image noise was significantly lower in low-dose CT with 50% ASIR-V than routine-dose CT with FBP (p < 0.001). CONCLUSION Low-dose CT with ASIR-V may assess multi-organ abdominal trauma without impairment of image quality, compared to routinedose CT with FBP. CLINICAL RELEVANCE/APPLICATION Low-dose CT with ASIR-V can allowed reduction of radiation exposure while maintaining the diagnostic performance in the evaluation of multi-organ trauma. RC508-09 Imaging of Hip Trauma W ednesday, Nov. 30 10:30AM - 11:00AM Room: S405AB Participants Bharti Khurana, MD, Boston, MA (Presenter) Nothing to Disclose LEARNING OBJECTIVES View learning objectives under the main course title. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Bharti Khurana, MD - 2014 Honored Educator RC508-10 A Pathomorphometric Study of Pelvic Ring Reduction by Binders after Trauma and Effects on Hemorrhage Control W ednesday, Nov. 30 11:00AM - 11:10AM Room: S405AB Participants David Dreizin, MD, Baltimore, MD (Presenter) Nothing to Disclose Daniel C. Mascarenhas, BS, Cinnaminson, NJ (Abstract Co-Author) Nothing to Disclose Jason Nascone, MD, Baltimore, MD (Abstract Co-Author) Royalties, Johnson & Johnson Consultant, Smith & Nephew plc Royalties, Imaging Diagnostic Systems, Inc PURPOSE Clinical markers of hemorrhage and unidimensional plain film measurements are limited for determining benefit from pelvic binders. We assessed adequacy of reduction in 3 orthogonal planes at CT and effects on segmented pelvic hematoma volumes (HMVs) for 3 major classes of instability METHOD AND MATERIALS The CT studies of 56 consecutively selected patients with binders were compared to 53 non-binder controls frequency-matched to within 15% differences for a given Tile grade determined by an orthopedist (Tile A-stable, B-rotationally unstable, C- rotationally and vertically unstable). All underwent CT prior to any surgery. CT measurements of pubic symphysis diastasis/offset (PSD) and SI joint diastasis/offset (SID) were made (mm) in 3 planes (AP/lateral/vertical). Semi-automated region-growing segmentation (iNtuition) was used to determine pelvic HMVs for each study. RESULTS Binders and controls had similar distributions of age, gender, and no significant difference in pelvic AIS or ISS. In Tile A (11 binders; 17 controls), there was no significant difference in morphometric measurements or HMVs, which were 80 mL and 107.2 mL respectively (p=0.32). In Tile B (rot unstable- 22 binders; 20 controls), AP PSD (1.91 vs 0.59), vert PSD (1.75 vs 1.12), and vert SID (0.44 vs 0.43) in binders vs controls were not significantly different, but lat PSD, lat SID, and HMVs were lower (6.82 vs 12.6, p=0.02; 2.45 vs 4.87, p <0.0001; and 160 vs 325 mL respectively, p=0.01) with binders. In Tile C (globally unstable) (21 binders; 16 controls), lat PSD (9.93 vs 10.3) & lat SID (7.72 vs 8.34) were not significantly different. There was substantial vert SID (4.56 vs 5.00, p=0.80) in Tile C, which did not reduce w binders. AP PSD (8.51 vs 1.88, p = 0.03), and vert PSD (8.22 vs 1.95, p < 0.0001) were increased w binders. AP SID (4.96 vs 2.44, p=0.09) increased in binders, approaching significance. Pubic bone override was only seen in the Tile C binder group (5 patients). HMVs were not decreased w/ binders (269 vs 255 mL, p=0.56) CONCLUSION Binders effectively reduce Tile B injuries and decrease hematoma volumes. In Tile C, binders increase distortion and fail to decrease hematoma volumes. CLINICAL RELEVANCE/APPLICATION Binders are thought to lmit hemorrhage by reducing the pelvic ring. We show that this is the case for rotationally unstable injuries, but binders further distort the globally unstable pelvis, and fail to reduce hemorrhage.in these injuries. RC508-11 CT Angiography of Peripheral Vascular Imaging W ednesday, Nov. 30 11:10AM - 11:40AM Room: S405AB Participants Scott D. Steenburg, MD, Zionsville, IN, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Describe optimal CTA imaging protocols and strategies for the evaluation of suspected peripheral vascular injuries. 2) Identify the various imaging manifestations of peripheral vascular injuries. 3) Recognize limitations and pitfalls in the diagnosis of peripheral vascular injuries. 4) Recognize when further evaluation with catheter angiography or surgical exploration are required. ABSTRACT Peripheral vascular injuries constitute between 40-75% of vascular injuries in civilian trauma centers, and may result from blunt or penetrating trauma. These injuries place the patient at risk for fatal exsanguination, multi-organ failure from hemorrhagic shock and limb loss. "Hard" signs of peripheral vascular injuries strongly correlate with the presence of injury, however injuries may still exist even in the absence of positive clinical findings. Thus, imaging supplementation is an important part of comprehensive patient evaluation. A multi-modality approach to peripheral vascular injuries will be presented, and reflecting current trends, emphasis will be placed on evaluation with MDCT angiography. The imaging appearances of the most common types of vascular injuries will be presented using a case based approach. RC508-12 Outcome in Renal Trauma: Is it Time to Revise the AAST Renal Injury Scale? A Retrospective Study in 367 Patients W ednesday, Nov. 30 11:40AM - 11:50AM Room: S405AB Participants Anna Luger, Innsbruck, Austria (Presenter) Nothing to Disclose Bernhard Glodny, MD, Innsbruck, Austria (Abstract Co-Author) Nothing to Disclose Alexander Loizides, MD, Innsbruck, Austria (Abstract Co-Author) Nothing to Disclose Johannes Petersen, MD, Innsbruck, Austria (Abstract Co-Author) Nothing to Disclose Leonhard Gruber, Innsbruck, Austria (Abstract Co-Author) Nothing to Disclose Peter Rehder, Innsbruck, Austria (Abstract Co-Author) Nothing to Disclose PURPOSE The aim of the study was to apply the AAST Renal Injury Scale (AAST RIS) in a large cohort, to show the weakness of the Scaling System and to find significant parameters for a new classification. METHOD AND MATERIALS All renal traumas over the last 10 years were analyzed, including demographics, the Injury Scaling System, accompanying injuries and radiologic methods. Cross-section of hematomas, infarcts and depth of lacerations were measured. Active bleeding, urinoma, persisting nephrogramm, congenital abnormalies and all accompanying injuries were documented. We performed regression analysis in order to predict therapeutic procedures such as angiography and surgery in renal trauma. RESULTS A total of 367 patients (61 female) with a mean age of 36.4 ± 19.5 years had blunt renal trauma. In 277 (60%) renal injuries the AAST Scale was not applicable. The main causes were undefined tissue infarction, persisting nephrogramms, active bleeding and adjacent renal vessels involved in trauma. Furthermore the AAST Score could not predict outcome, therapy or even length of hospitalization.Our findings indicate active bleeding as a predictor for angiography and the cross-section dimension of hematoma, infarction and depth of laceration as predictors for surgery. CONCLUSION The AAST Renal Injury Scale does not predict therapeutic procedures and is not applicable in 60 % of injured kidneys. Our findings indicate the needs to develop of a new Scaling System including significant parameters like active bleeding, cross-section dimension of hematoma and injuries like persisting nephrogram and adjacent renal vessel bleeding. CLINICAL RELEVANCE/APPLICATION The proposed predictors may change the current AAST Classification in order to enhance prognostic power in therapy. RC508-13 Trends in the Volume of Computed Tomography Imaging in Trauma W ednesday, Nov. 30 11:50AM - 12:00PM Room: S405AB Awards Student Travel Stipend Award Participants Michael J. Hsu, MD, Boston, MA (Presenter) Nothing to Disclose Michael Wasserman, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jennifer Xiao, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Venkata Satyam, Boston, MA (Abstract Co-Author) Nothing to Disclose Tina Shiang, Boston, MA (Abstract Co-Author) Nothing to Disclose Deepan Paul, Boston, MA (Abstract Co-Author) Nothing to Disclose Ahmed Y. El-Araby, MD , West Warwick, RI (Abstract Co-Author) Nothing to Disclose Vaeman Chintamaneni, Boston, MA (Abstract Co-Author) Nothing to Disclose Robert Burns, Boston, MA (Abstract Co-Author) Nothing to Disclose Arthur Baghdanian, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Jorge A. Soto, MD, Boston, MA (Abstract Co-Author) Royalties, Reed Elsevier Stephan W. Anderson, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE The purpose of this study is to examine seasonal trends in the volume of CT trauma imaging, and to determine what environmental and circumstantial factors influence the quantity of studies performed. METHOD AND MATERIALS This HIPAA-compliant, retrospective study performed at our urban academic teaching hospital was approved by the Institutional Review Board (IRB); informed consent was waived.The daily volume of trauma CT examinations performed at our urban Level 1 trauma center over a two-year period was collected. Our institution is located in a major city with large seasonal variations in weather. The effects of the time of day, day of the week, month of the year, as well as weather, on trauma imaging volume was analyzed. RESULTS When analyzed as a function of the time of day, there are hourly variations in volume of trauma CT imaging performed throughout the day. Uptrends in activity begin at 10 AM and 7 PM. There is a plateau of high volume from 8 PM to 12 AM. There is an additional peak at 4 AM. The lowest volume of trauma CT imaging is performed from the hours of 5 AM to 9 AM. When analyzed as a function of the day of the week, the highest volume of trauma CT imaging was performed on Saturday, followed by Friday and Sunday. There is a gradual downtrend from Monday to Thursday.When analyzed as a function of the month of the year, there are monthly variations in trauma imaging volumes with an 88% increase in CT trauma imaging during the peak month of July as compared to the nadir of April.When analyzed as a function of weather, the lowest months of activity coincide with the winter and there is strong correlation between volume of CT imaging and higher temperatures. There is also an inverse relationship between snowfall and quantity of trauma CT imaging. CONCLUSION There are predictable patterns in trauma CT imaging volume based on the time of day, day of the week and month of the year. Seasonal variations in temperature, snowfall and sunlight also affect volume. There is particularly high volume in the month of July. CLINICAL RELEVANCE/APPLICATION Identifying factors that influence changes in CT imaging volume is important for allocating departmental resources to appropriately address predictable variations in the amount of trauma imaging performed. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator RC512 Thoracic Aortic Emergencies (An Interactive Session) W ednesday, Nov. 30 8:30AM - 10:00AM Room: E353B VA ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Dominik Fleischmann, MD, Palo Alto, CA (Moderator) Research support, Siemens AG; Sub-Events RC512A The Spectrum of Type A Dissection Participants Anne S. Chin, MD, Palo Alto, CA (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Review the pathology, epidemiology, and natural history of acute type A aortic dissection. 2) Describe the imaging strategies for acute aortic syndromes. 3) Review the recent classification of acute aortic dissection. 4) Illustrate imaging findings of the spectrum of acute type A aortic dissection, with a focus on recognizing subtle CT angiographic findings related to the lesser known 'Class 3' aortic limited intimal tear or 'limited dissection.' ABSTRACT The traditional Stanford classification distinguishes between dissections involving the ascending aorta (Type A) from those that do not involve the ascending aorta (Type B). Type A aortic dissection is rare, but remains the most lethal of aortic disorders requiring prompt surgical intervention. The common pathologic denominator in patients with acute dissection is an abnormal aortic media ('cystic medial necrosis') which can be found in genetic/inherited diseases (e.g. Marfan's) but also in patients with severe hypertension. The CT imaging strategy of suspected acute aortic syndrome should always include (i) non-enhanced images to assess for intramural hematoma (IMH); when the index of suspicion for aortic dissection is high, also consider (ii) EKG-gating for motion-free evaluation of the aortic root/ascending aorta, and (iii) including common femoral arteries in the CTA scan range to assess lesion extent and identify a percutaneous access route. The spectrum of aortic dissection has recently been classified as the following: Class 1 classic dissection with true and false lumen separated by an intimal flap; Class 2 IMH; Class 3 limited intimal tear or limited dissection; Class 4 penetrating atherosclerotic ulcer (PAU); and Class 5 iatrogenic/traumatic. A clarification and modified conceptual classification of aortic dissection will be provided, along with illustrative examples of these aortic lesions. Particular focus will be given to the lesser known Class 3 'limited dissection' which is described as a subtle and eccentric bulge of the aortic wall. While it has been reported to elude current imaging techniques, emphasis will be made on recognizing subtle CTA imaging findings characteristic of this uncommon but important dissection variant. RC512B Acute and Chronic Complications of Aortic Dissection Participants Anna M. Sailer, MD, MBA, Maastricht, Netherlands, ( [email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Describe the natural history and radiological patterns of early and late complications of Type B aortic dissections. 2) Differentiate the mechanisms of branch ischemia and false lumen dilatation. 3) Assess different treatment strategies for acute and chronic dissections. ABSTRACT RC512C Traumatic Aortic Injuries Participants Savvas Nicolaou, MD, Vancouver, BC (Presenter) Institutional research agreement, Siemens AG LEARNING OBJECTIVES 1) Discuss the different mechanisms of injuries, pathophysiology, and types of traumatic aortic injuries including aortic dissection, laceration, transection, pseudoaneurysm and intramural hematoma. 2) Review techniques and advances in imaging including DECT/Spectral and ultra-high-pitch imaging to optimize imaging of traumatic aortic injuries and the role of gating, MRI, and TEE. 3) Discuss and demonstrate examples of the grading scheme for traumatic aortic injuries. 4) Demonstrate imaging pitfalls which can cause misinterpretation of traumatic aortic injuries. 5) Review the appropriate management and treatment options, including open surgical repair and percutaneous endovascular repair, for the traumatic aortic injuries. ABSTRACT ERS-W EA Emergency Radiology Wednesday Poster Discussions W ednesday, Nov. 30 12:15PM - 12:45PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Douglas S. Katz, MD, Mineola, NY (Moderator) Nothing to Disclose Sub-Events ER228-SDWEA1 Evaluation of Bone Marrow Edema in Thoracolumbar Spinal Trauma: Early Experience with the Third Generation Dual Source CT Technology in the Acute Setting Station #1 Participants Sudha R. Muly, MBBS, FRCR, Vancouver, BC (Presenter) Nothing to Disclose Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG Luck J. Louis, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG PURPOSE Traumatic bone marrow edema results in small but measurable increase in CT attenuation values due to hemorrhage and increased interstitial fluid within the bone marrow cavity. To evaluate the sensitivity and specificity of dual energy CT (DECT) in detecting bone marrow edema (BME) in thoracic and lumbar spine. To identify the pitfalls and common artifacts which limit DECT bone marrow assessment. METHOD AND MATERIALS In this retrospective study, 26 trauma patients who underwent DECT scanning of the thoracic and lumbar using a third generation dual source CT scanner (Definition FORCE, Siemens Health care, Germany) between January and April of 2016 were evaluated. There were 57 vertebral bodies assessed for bone marrow edema. The DECT data (100 kv and 150kvSN) was reconstructed using bone marrow edema algorithm on the syngovia platform VB 10. Visual analysis using color overlay images and quantitative objective analysis was performed using dual energy region of interest on the vertebral bodies to evaluate presence of bone marrow edema RESULTS Dual energy CT showed a sensitivity of 89% and specificity of 88%. The positive predictive value of was close to 96% and a negative predictive value close to 70%. There were 12 cases, which were indeterminate on grey scale mixed data CT sets simulating a 120 kvp scan and analysis of dual energy CT BME helped differentiate acute versus chronic fractures.Subtle end plate compression fracture may be difficult to evaluate on dual energy due to close proximity of the area of interest to the cortex. Movement and streak artifact cause spurious positive results and that could be alleviated with faster rotation, wider collimation and higher pitch. CONCLUSION Due to its superior quality and the advancements in dual-energy CT technology with materialdecomposition, detection of bone marrow edema helps to identify subtle fractures and to differentiate acute from chronic fractures with high sensitivity and specificity. CLINICAL RELEVANCE/APPLICATION We believe that dual-energy CT will serve as a good replacement for detection of bone marrow edema for patients who have a contraindication to MR imaging or when there is no immediate availability MRI due to resource constraints. But more importantly DECT can increase the diagnostic confidence in confirming a spinal fracture as acute when BME is present in the setting of trauma where CT is recognized as the Gold standard for the evaluation of spinal trauma. ER229-SDWEA2 Utilization of MRI and CT Imaging for ED Patients with Clinically Suspected Stroke: A Retrospective Institutional Review, Comparing True Negatives to True Positive Stroke Population Station #2 Participants Sarika Pamarthy, MBBS, MS, Columbus, OH (Abstract Co-Author) Nothing to Disclose Manav Bhalla, MD , Milwaukee, WI (Presenter) Nothing to Disclose John L. Ulmer, MD, Milwaukee, WI (Abstract Co-Author) Stockholder, Prism Clinical Imaging, Inc Medical Advisory Board, General Electric Company Andrew P. Klein, MD, Pewaukee, WI (Abstract Co-Author) Nothing to Disclose Kieran E. McAvoy, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Leighton P. Mark, MD, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Stephen A. Quinet, MD, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Namrata Bhalla, Brookfield, WI (Abstract Co-Author) Nothing to Disclose PURPOSE CT/MRI neurologic stroke (3rd leading cause of death in the US) imaging has immense value in guiding patient management. However, the rate of CT and MRI utilization in patients ultimately found not to have stroke is understandably high in the ED setting, as ‘time is brain’ and the consequences of misdiagnosing a vascular event are profound. Yet, the judicious utilization of imaging resources in today’s healthcare environment is more important than ever. Our study seeks to evaluate the clinical parameters that differentiate stroke negative patients to those who were positive. The information could aid clinical decision-making and optimize stroke imaging algorithms. METHOD AND MATERIALS The EHR of 500 patients who presented with stroke like symptoms, and had CT/MRI performed in a span of 24 hours, were retrospectively reviewed. The predictive values of CT and MRI were obtained by comparing imaging diagnosis with the final clinical diagnosis at discharge. Final diagnosis of stroke negative patients were reviewed, and their clinical profile (age, gender, race and risk factors) were compared with stroke positive patients. RESULTS Radiologic data analysis revealed 250/500 patients (50%) were ‘true negative for stroke based on final clinical discharge diagnoses. The clinical non-stroke diagnoses were as follows: 53/250 with TIA, 19/250 with migraine, 15/250 with seizure, 10/250 with emergent hypertension, 10/250 with behavioral or psychogenic (depression, adjustment disorder, etc.), 9/250 with UTI, and 138 with miscellaneous neurologic or non-neurologic diagnoses. Significant differences in mean age, absence of vascular risk factors and mean NIHSS score were noted between the true negatives and true positives. CONCLUSION Many neurological presentations may mimic stroke clinically, requiring imaging for diagnosis and management. However, imaging resources are limited and are ever shrinking in the current healthcare environment, fostering an emphasis on appropriate utilization. Our data indicates that up to 50% of patients imaged for stroke are ultimately found to have other diagnoses, providing a baseline to test refinements in clinical stroke algorithms that may optimize utilization of neuroimaging in the ED. CLINICAL RELEVANCE/APPLICATION Clinical parameters of patients presenting with stroke like symptoms may be used to optimize algorithms that facilitate appropriate utilization of imaging modalities for stroke imaging. ER230-SDWEA3 Spontaneous Visceral Artery Dissection: Clinical and Radiologic Characteristics, Management Strategies and Patients' Outcome Station #3 Participants Min Yeong Kim, MD, Seoul, Korea, Republic Of (Presenter) Nothing to Disclose PURPOSE To report CT finidngs of spontaneous visceral artery dissection (SVAD) with clinical circumstances.To evaluate treatment strategies correlated with patients' prognosis. METHOD AND MATERIALS For 4 years, 18 patients had been diagnosed as SVAD on enhanced abdominal CT scans. The clinical characteristics, comorbidities, risk factors and the treatment with prognosis were evaluated by data from the electronic medical records. Analysis of CT exams included location of SVAD, affected visceral organs, abnormalities of other abdominal arteries. If endovascular intervention was performed, angiographic finidngs were also reviewed. RESULTS Fifteteen patients were men and average age was 49.9 years (range, 29-84). The location of SVAD was superior mesenteric artery (SMA) only in 9, celiac axis (CA) only in 5, both SMA and CA in 2, renal artery (RA) in 2 patients. In one patient, CA dissection developed 20 months after SMA dissection. Most common symptoms were acute abdominal pain in 10 patients, but all two patients with RA dissection complained acute flank pain with segmental infarct in corresponding renal parenchyma. There are no organic ischemia in SMA dissection and only one case of CA dissection resulted in segmental splenic infarct. Only 7 patients had hypertension, no patients had coronary arterial diseases while metabolic diseases were more common: diabetus mellitus (DM) in 5, impaired glucose tolerance (IGT) in 7, dyslipidemia in 8 patients. Smokers were 6 patients and CT finidngs of atherosclerosis were found in 3 patients. No patients underwent for surgical procedures and 4 patient underwent endovascular procedures, one stenting and 3 angioplasty. The others were managed by medical treatment. CONCLUSION Clinical manifestation of SVAD is very similar to other conditions of acute abdomen. Most affected persons are late thirties to ealry fifties males. SMA is most common site of SVAD. The major risk factors are metabolic disease such as DM, IGT and dyslipidemia, however smoking, hypertension or other cardiovascular diseases are not frequent in SVAD. Most SVAD do not result visceral ischemia and are treated by medical management. Although dissection in RA is rarer than in CA or SMA, renal infarct is serious problem and prompt management must be performed. CLINICAL RELEVANCE/APPLICATION SVAD is emerging disease entity in acute abdomen. It is important to understand both CT finidngs and clinical characteristics of SVAD for accurate diagnosis and appropriate management. ER231-SDWEA4 Criteria-based Direct Access to Polytrauma Whole-body CT Scans in the Emergency Department, and Impact on Proportion of Normal Scans at a Major Trauma Centre Station #4 Awards Student Travel Stipend Award Participants James S. Kho, MBBCh, Brighton, United Kingdom (Presenter) Nothing to Disclose Ahmed Daghir, MRCP, FRCR, Oxford, United Kingdom (Abstract Co-Author) Nothing to Disclose PURPOSE A set of criteria for direct Emergency Department access to polytrauma whole-body CT scans, was introduced to help guide clinical decision making and speed up patient imaging in the Emergency Department. This study aims to determine if use of criteria-based patient selection for polytrauma whole-body CT scans in the Emergency Department is associated with a change in proportion of normal polytrauma whole-body CT scans. METHOD AND MATERIALS Criteria-based direct Emergency Department access to polytrauma whole-body CT scans was introduced over 2013 at our institution, with criteria modified from patient inclusion criteria to the REACT-2 trial. When the criteria are met the patient proceeds directly to CT without prior discussion with a radiologist. A retrospective sample of 60 polytrauma whole-body CT scans per year was obtained over a fixed 2 month period in 2012, 2014 and 2015. The consultant radiology reports of these CT scans were retrieved from the hospital's radiology information system. Scans were categorised based on the consultant reports as normal (no acute injury or subcutaneous soft tissue injury only), or abnormal (any acute injury other than subcutaneous soft tissue injury). The proportion of normal polytrauma CT scans for 2012 prior to the introduction of the criteria-based patient selection, was compared to 2014 and 2015 post-introduction of the criteria. RESULTS The proportion of normal polytrauma whole-body CT scans in this major trauma centre, rose from 27% in 2012, to 33% in 2014, to 47% in 2015 (p = 0.02, Z test for equality of proportions). The introduction of criteria-based direct Emergency Department access to polytrauma whole-body CT scans in 2013 thus appears to be associated with a significant rise in proportion of normal scans in our major trauma centre. Our percentage of normal polytrauma whole-body CT scans in 2015 of 47% exceeds published percentages of 27-37% for such scans at other trauma centres in this country. CONCLUSION Introduction of criteria-based direct access of Emergency Department to polytrauma whole-body CT has been associated with a rise in proportion of normal scans at our major trauma centre, from 27% to 47%. CLINICAL RELEVANCE/APPLICATION The rising proportion of normal polytrauma CT studies suggests criteria-based direct access to polytrauma whole-body CT in our institution has lowered the threshold for selection of patients that receive these scans. ER232-SDWEA5 Reasonable Utilization of CT Angiogram for Evaluation of Spontaneous Parenchymal Hemorrhage Station #5 Awards Student Travel Stipend Award Participants Li-Hsiang Yen, MD, West Orange, NJ (Presenter) Nothing to Disclose Ali F. Jon, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Shira Slasky, MD, Tenafly, NJ (Abstract Co-Author) Nothing to Disclose PURPOSE Spontaneous, non-traumatic parenchymal hemorrhage may be caused by a variety of etiologies. CT angiogram (CTA) is a fast and effective modality to diagnose underlying vascular malformations. CTA has limitations due to its high ionizing radiation dose and its cost. Judicious utilization of CTA is necessary to follow the dictum of ALARA. Current guidelines (AHA/ASA 2015) recommend using CTA to evaluate for an underlying structural lesion if there is clinical or radiological suspicion. Risk factors for underlying structural lesions include: age <65 years, female sex, nonsmoker, lobar hemorrhage, intraventricular extension, and absence of hypertension or coagulopathy. Our hypothesis was that many low risk patients with parenchymal hemorrhage in our institution were imaged with CTA unnecessarily. METHOD AND MATERIALS We reviewed our PACS for CT angiograms of the head performed during 2014 and 2015 to identify all patients with intracranial parenchymal hemorrhage. Any abnormality of the cerebral vasculature was subsequently reviewed. Arteriovenous malformation or cerebral aneurysm that may have potentially caused the hematoma were considered positive findings. Other vascular abnormalities such as stenosis were considered negative. Electronic medical records were reviewed for relevant clinical information. RESULTS We identified a total of 74 patients with parenchymal hemorrhage, 36 male and 38 female. 12% of the total patients had positive CTA findings. 20% of these patients were older than 65 years. 10 patients (13.5%) were imaged despite not having any of the risk factors and all had a negative CTA result. The yield of CTA for evaluation of parenchymal hemorrhage was previously reported as 14.6% (AJNR 2009), which is similar to our study. CONCLUSION 13.5% of CT angiograms of the head performed for parenchymal hemorrhage were unnecessary as per the AHA/ASA guidelines. Implementation of clinical guidelines into a clinical decision making system may be helpful to reduce unnecessary examinations. We will try to implement the guidelines into our electronic ordering system and follow up on results after implementation. CLINICAL RELEVANCE/APPLICATION We have identified a number of unnecessary examination that may be avoided by following the AHA/ASA guideline and will perform a follow-up study to assess the reduction of unnecessary examinations after implementing a check list into our electronic ordering system. ERS-W EB Emergency Radiology Wednesday Poster Discussions W ednesday, Nov. 30 12:45PM - 1:15PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Douglas S. Katz, MD, Mineola, NY (Moderator) Nothing to Disclose Sub-Events ER233-SDWEB1 The role of MD-CECT in the Diagnosis of Necrotizing Fasciitis and Correlation with the LRINEC Score Station #1 Participants Marco Di Girolamo, MD, Rome, Italy (Presenter) Nothing to Disclose Francesco Carbonetti, MD, Rome-Roma, Italy (Abstract Co-Author) Nothing to Disclose Antonio Cremona, Rome, Italy (Abstract Co-Author) Nothing to Disclose Daniela Sergi, Rome, Italy (Abstract Co-Author) Nothing to Disclose Valentina Caturano, Rome, Italy (Abstract Co-Author) Nothing to Disclose Elsa Iannicelli, MD, Rome, Italy (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the diagnostic efficacy of the CT findings in predicting the diagnosis of Necrotizing Fasciitis (NF). METHOD AND MATERIALS In a period of a year 36 pts with a clinical suspicion of NF underwent to CE-MDCT .CT findings studied were : involvement and thickening of the muscular fascia, fluid collections along the deep fascial sheaths , extension of oedema into the intramuscular septa and the muscles, low attenuation areas in the deeper fascial planes suggestive for colliquative necrosis, a non enhancement of the muscular fascia and vascular thrombosis.Radiological findings were compared with the LRINEC score and with the surgical data. RESULTS CT findings were suggestive for NF in 10 pts , for non-NF in 2 pts and for gas-gangrene in 2 pts .The rest of the pts showed CT finding suggestive for cellulitis (10 pts) , myositis (5 pts) , soft tissue abscess ( 7 pts).Among the patients with CT findings suggestive for NF, non-NF and gas gangrene , 9 pts showed a non enhancing fascia, subcutaneous gas was present in 12 pts, involvement of the fascia in 12 pts, fluid collections along the deep fascial sheaths in 7 pts ,low attenuation areas in the deeper fascial planes in 3 pts. Surgical examination confirmed the diagnosis of NF in 12 pts who showed at the CE-MDCT a non enhancement of the fascia (9/12), low areas of attenuation (3/12), fluid collections ( 4/12), presence of subcutaneous gas (10/12) . The LRINEC score in pts with NF was equal or superior to 6 points : 6 pts had a score of 6/8 , 4 pts a score of 7/8 , 2 pts a score of 8/8 . The diagnoses of the other pts (cellulitis 10 pts, myositis 5 pts, musculoskeletal abscess 7 pts) were confirmed. CONCLUSION The presence of a non-enhancing fascia after contrast medium administration, the involvement of the fascia and the presence of subcutaneous gas are the radiological findings mostly related to NF, and could strongly suggest to the radiologist the presence of NF; these findings with an intermediate-high LRINEC should address to a surgical evaluation. CT could discriminate NF from the most common musculoskeletal infections. CLINICAL RELEVANCE/APPLICATION NF is a fatal disease if it is not treated, in order to permit a prompt surgical intervention radiological findings correlated with the LRINEC score permit a better evaluation of the pts disease and a prompt surgical intervention in order to avoid the complication of NF. ER234-SDWEB2 Acute Mesenteric Isquemia? Can We Predict It? Station #2 Participants Lorena F. Rodriguez-Gijon, MD, Madrid, Spain (Presenter) Nothing to Disclose Angel Aguado, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Milagros Marti, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Aurea Diez Tascon, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Maria Jose Simon, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Alfonso Martin Diaz, BMedSc, San Sebastian De Los Reyes, Spain (Abstract Co-Author) Nothing to Disclose Lucia Fernandez Rodriguez, BMBS, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Carolina Martinez Gamarra, MD, Madrid, Spain (Abstract Co-Author) Nothing to Disclose Maria Claudia Pulido, Madrid, Spain (Abstract Co-Author) Nothing to Disclose PURPOSE Acute mesenteric ischemia remains a difficult diagnosis to establish on a clinic base, so diagnosis requires advanced imaging techniques, such as CT angiography or invasive techniques.Recent studies suggest that the elevation of the neutrophyl to lymphocyte ratio (NLR) is present in the moment of the acute mesenteric ischemia (AMI) diagnosis.The objective of our work is to study the association between NRL and radiological signs of AMI by all causes. METHOD AND MATERIALS A retrospective, case-control study has been performed, within the years 2013-2016 in a third level hospital. 34 cases with AMI diagnosed by TC and confirmed by histology or clinical outcome has been taken. As control group, there were 34 patients diagnosed with a no-AMI disease by TC and confirmed by surgical or histological findings.Study variables were sex, age, NRL, CT diagnosis, pathological diagnosis, cause of AMI and radiological signs described in other reports for AMI.Non parametric test (MannWhitney) and chi 2 or Fischer`s exact test were performed to analyze the differences between case and control groups. To evaluate the NLR discriminative capacity, ROC curves were used. RESULTS We observed statistically significant association of NRL with the following radiological signs in patients with AMI: parietal thickening of the ascending colon (p = 0.04), transverse colon (p = 0.04), descending colon (p = 0.029) and sigma (p = 0.03) and with occlusion of the superior mesenteric artery (SMA) (p = 0.03).Including AMI of any cause, the area under the ROC curve (AUC) was 0.6 (CI 95%: 0.46-0.74; p=0.151). In the cases of AMI by SMA occlusion, the AUC was 0.83 (CI 95%: 0.67-0.98; p=0.004). There was no patient with diagnose of SMA occlusion AMI with a NLR <5. (Negative predictive value: 100%). The optimal cut-off by Youden’s index was 18.7 (sensitivity 77.8% and specificity of 80%). CONCLUSION In our study, ability NRL to discriminate between cases and controls was low but the area under the curve of NRL to classify AMI by SMA occlusion with respect to other causes was 0.83, so we propose that at high values of NRL, an arterial phase helix should be performed. CLINICAL RELEVANCE/APPLICATION The results of our study show an association between NRL and ischemia of arterial origin, so that a high NRL value could consider a predictor factor of arterial origin AMI and an arterial phase helix should be performed in these cases. ER235-SDWEB3 Role of CT in the Definition of Therapeutic Approach in Polytrauma Patients with Kidney Injury Station #3 Awards Student Travel Stipend Award Participants Bruno Tuscano, MD, Milano, Italy (Presenter) Nothing to Disclose Luca Caschera, MD, Milano, Italy (Abstract Co-Author) Nothing to Disclose Ettore Colombo, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Stefania Cimbanassi, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Osvaldo Chiara, Milan, Italy (Abstract Co-Author) Nothing to Disclose Angelo Vanzulli, MD, Segrate, Italy (Abstract Co-Author) Travel support, Bracco Group PURPOSE To evaluate the role of CT in the management of kidney injury, on basis of OIS degree (Organ Injury Scale) and outcome. METHOD AND MATERIALS Retrospective study of 91 polytrauma patients with kidney lesions classified according to the American Association of Trauma Surgery in five degrees of gravity. Patients were admitted to a large metropolitan hospital from 2011 to 2015 (44 OIS 1, 18 OIS 2, 11 OIS 3, 16 OIS 4 and 2 OIS 5). For each case imaging data (CT) and treatment strategy were collected. RESULTS In almost all OIS 1 to 3 degree kidney lesions conservative treatment was chosen, while in lesions of OIS 4 and 5, surgical (n = 2) or minimally invasive (n = 12) procedures were performed. CT revealed urinoma in 12.1% of cases. In 6 cases a ureteral stent was positioned after ascending pyelography which confirmed the injury; in 5, with limited spreading of the contrast agent, a conservative approach was chosen. The CT scan showed in 3 patients (OIS 4) arterial blushing of renal vessels and embolization was performed. In 1 patient (OIS 2) the first CT did not reveal the presence of renal artery branch pseudoaneurysm, identified in the subsequent CT, treated with embolization. In 2 patients (OIS 4) total nephrectomy was done for the impossibility to reconstruct the urinary tract and renal parenchyma. In 2 patients (1 OIS 4, 1 OIS 5) CT documented renal artery occlusion, and both cases were treated with stenting. CONCLUSION CT has provided reliable evaluation of all lesion degrees, allowing in most cases minimally invasive interventions and reducing nephrectomy rates. CT monitoring allowed non operative management in many patients. CLINICAL RELEVANCE/APPLICATION Contrast enhanced CT in polytrauma patients with renal injuries reduce total or partial nephrectomy rate in favor of conservative management. ER236-SDWEB4 The Application of Dual-energy Technique to Whole-body CT in Blunt Trauma Patients: Can the Virtual-unenhanced CT Images Substitute Unenhanced CT Images? Station #4 Participants Yukichi Tanahashi, MD, Tokyo, Japan (Presenter) Nothing to Disclose Hiroshi Kondo, MD, Tokyo, Japan (Abstract Co-Author) Nothing to Disclose Satoshi Goshima, MD, PhD, Gifu, Japan (Abstract Co-Author) Nothing to Disclose Nobuyuki Kawai, MD, Gifu, Japan (Abstract Co-Author) Nothing to Disclose Yoshifumi Noda, MD,PhD, Gifu, Japan (Abstract Co-Author) Nothing to Disclose Hiroshi Kawada, MD, Gifu, Japan (Abstract Co-Author) Nothing to Disclose Toshihisa Kojima, MD, Gifu, Japan (Abstract Co-Author) Nothing to Disclose Shigeru Furui, MD, Itabashi-Ku, Japan (Abstract Co-Author) Nothing to Disclose Masayuki Matsuo, Gifu, Japan (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate the efficacy of virtual-unenhanced CT for the assessment of blunt trauma patients. METHOD AND MATERIALS Eighty-two trauma patients (55 men and 27 women; mean age, 51.6 yrs; range, 12-90 yrs) who underwent whole-body dynamic contrast-enhanced CT with dual-energy technique, following unenhanced CT, constituted study population. The virtualunenhanced CT image was reconstructed. Two observers independently and randomly reviewed images in three image sets; 1st, contrast-enhanced images, 2nd, combined unenhanced and contrast-enhanced images, and 3rd, combined virtual-unenhanced and contrast-enhanced images for the evaluation of traumatic change. The confidence level of traumatic change probability (visceral trauma, bone trauma, and extravasation of contrast media) were scored by 5-point scale for each image sets. Areas under the receiver operating characteristic curve (AUC) for the detection of traumatic change was evaluated. The image quality and radiation exposure were assessed. RESULTS Diagnosis of 63 visceral injuries in 47 patients and 138 bone fracture in 59 patients were clinically established. No significant difference was found in AUCs for visceral (0.90, 0.90, and 0.90), bone injury (0.87, 0.87 and 0.87), extravasation of contrast media (0.72, 0.72, and 0.72) among three image sets (P = 0.68, 0.50, and 0.51). The artifact and noise were worth in virtual-unenhanced images (P < 0.017). The Diagnostic acceptability of virtual-unenhanced image was substantial for all image. Mean DLP of unenhanced CT, arterial phase and venous phase were 1249.9 mGy*cm, 742.2 mGy*cm, and 1246.0mGy*cm, respectively. CONCLUSION Combined virtual-unenhanced and contrast-enhanced images showed comparable diagnostic performance of trauma with contrastenhanced images alone and combined unenhanced and contrast-enhanced images. CLINICAL RELEVANCE/APPLICATION Our result showed unenhanced CT can be omitted in trauma patients and substituted by virtual-unenhanced CT reconstructed from dual-energy CT as needed, resulting in the decrease of radiation exposure. ER237-SDWEB5 Pattern of Head Injuries in the Elderly Station #5 Awards Student Travel Stipend Award Participants Kenedy A. Foryoung, MD, Hamden, DC (Presenter) Nothing to Disclose Felix T. Nautsch, MS, BA, New Haven, CT (Abstract Co-Author) Nothing to Disclose Xiao Wu, New Haven, CT (Abstract Co-Author) Nothing to Disclose Ajay Malhotra, MD, Stamford, CT (Abstract Co-Author) Nothing to Disclose Diego B. Nunez JR, MD, MPH, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE Head and cervical spine computed tomography (CT) are the workhorse modalities for the evaluation of neurologic trauma in the emergency setting. Knowledge of typical injury patterns and typical injury mechanisms as they occur in different age groups may help improve performance by guiding search patterns, key ancillary data given to the radiologist and possibly reformatting algorithms. METHOD AND MATERIALS CT studies of the brain and brain and cervical spine of adults performed in the Emergency Department between 2/15/2014 and 2/15/2015 were retrieved from the electronic medical records. For all studies with critical findings, the images, reports and associated medical record were manually reviewed. Histories of trauma or possible trauma with findings of traumatic injuries by CT were included. The data was separated by Age into two groups aged above 65 and 18-64. We grouped fractures and hemorrhages by type and anatomic location. Collateral information such as anticoagulation status and additional history were manually retrieved. RESULTS A total of 384 studies with patients above the age of 65 and 518 studies with patients aged between 18 and 65 with critical results were identified for manual review. Following preliminary manual review approximately 70% met inclusion criteria by history and findings in both age groups. 85% of the group aged above 65 suffered a traumatic fall and 37% were on anti-coagulation. The most common traumatic bleed above the age of 65 was an acute subdural bleed, which occurred 35% of the time. The predominant cranial area of fracture was the face in 30% of all studies above 65. High velocity mechanisms of injury in the elderly were present in only 6% of the cases. Diffuse axonal injuries, parenchymal hemorrhage and arterial epidural collections were rare. While epidural and subarachnoid hemorrhage remained a relatively rare finding in the younger age group, the preponderance of subdural hemorrhages decreased to 23%. Similarly, high velocity injury mechanisms occurred about 10% of the time and a second predominant mechanism of injury, assault, occurred 12% of the time. CONCLUSION The elderly suffer specific injury patterns closely associated with their typical mechanisms of injury and anti-coagulation state. CLINICAL RELEVANCE/APPLICATION Injury patterns after blunt trauma might be different in the elderly patients relative to younger population. SSM07 Emergency Radiology (Emergency Neuroradiology) W ednesday, Nov. 30 3:00PM - 4:00PM Room: S403B NR CT ER AMA PRA Category 1 Credit ™: 1.00 ARRT Category A+ Credit: 1.00 Participants Jamlik-Omari Johnson, MD, Atlanta, GA (Moderator) Research Grant, Koninklijke Philips NV; Royalties, Cambridge University Press Scott D. Steenburg, MD, Zionsville, IN (Moderator) Nothing to Disclose Sub-Events SSM07-01 Potential for Lower Dose Spiral Head CT to Detect Intracranial Findings Causing Neurologic Deficit W ednesday, Nov. 30 3:00PM - 3:10PM Room: S403B Participants Joel G. Fletcher, MD, Rochester, MN (Presenter) Grant, Siemens AG; ; David R. De Lone, MD, Rochester, MN (Abstract Co-Author) Nothing to Disclose Amy L. Kotsenas, MD, Rochester, MN (Abstract Co-Author) Nothing to Disclose Norbert G. Campeau, MD, Rochester, MN (Abstract Co-Author) Nothing to Disclose Vance Lehman, MD, Rochester, MN (Abstract Co-Author) Nothing to Disclose Lifeng Yu, PhD, Chicago, IL (Abstract Co-Author) Nothing to Disclose Maria Shiung, Rochester, MN (Abstract Co-Author) Nothing to Disclose Adam Bartley, Rochester, MN (Abstract Co-Author) Nothing to Disclose Shuai Leng, PhD, Rochester, MN (Abstract Co-Author) Nothing to Disclose David R. Holmes Iii, PhD, Rochester, MN (Abstract Co-Author) Nothing to Disclose Alicia Toledano, DSc, Kensington, MD (Abstract Co-Author) Consultant, iCAD, Inc Rickey Carter, PhD, Rochester, MN (Abstract Co-Author) Nothing to Disclose Cynthia H. McCollough, PhD, Rochester, MN (Abstract Co-Author) Research Grant, Siemens AG PURPOSE To evaluate the ability of lower dose head CT using either standard filtered back projection (FBP) or iterative reconstruction (IR) to display intracranial findings (ICF) that may cause neurologic deficit. METHOD AND MATERIALS Using a retrospective, case-control design, CT projection data from 83 unenhanced spiral head CT exams in patients with suspected neurologic deficit were collected. Positive cases required presence of histopathology, surgery, progression of findings, or corresponding neurological deficit. Negative cases required negative CT findings and negative neurological assessment. Routine clinical images were obtained using 250 effective. mAs (emAs) and IR. Based on prior results and using validated noise insertion, four additional lower dose configurations were reconstructed (25 emAs -IR, 50 emAs -FBP and -IR, 100 emAs -FBP and -IR, 200 emAs -FBP). Three neuroradiologists circled ICF’s and provided a diagnosis, confidence (0 – 100), and image quality rating. Matching of reference and reader markings was performed by a non-reader neuroradiologist. The difference between the JAFROC figure-of-merit (FOM) at routine and lower dose configurations was estimated along with 95% confidence intervals (CIs), with the lower 95% CI limit required to be greater than -0.10 to demonstrate non-inferiority. RESULTS 63 ICF’s (25 infarcts, 6 intra- and 9 extra-axial hemorrhages, 25 masses; non-exclusive) were identified by reference standard in 40/83 (48%) patients with routine head CT (CTDI 38.3 mGy). JAFROC FOM at 250 emAs routine dose was 0.82 (95% CI: 0.76, 0.89). Using non-inferiority criteria, the JAFROC FOM was non-inferior for dose levels corresponding to ≥ 100 emAs when IR was utilized [100 emAs -IR FOM 0.78 (95% CI: 0.71, 0.85), with the difference from routine dose being -0.04 (95% CI: -0.08, 0.01)]. For 100 emAs -FBP, this difference was -0.06 (95% CI: -0.11, -0.02). This difference was worse and larger for lower dose levels. Diagnostic image quality was better at higher dose levels and with IR (p<0.05). CONCLUSION Observer performance for dose levels from 100 to 200 emAs was non-inferior to that observed at 250 emAs with IR, with IR preserving non-inferiority at a mean CTDI/SSDE of 15.2/10.5 mGy. CLINICAL RELEVANCE/APPLICATION Substantial opportunity exists for lowering radiation dose at unenhanced head CT with the use of iterative reconstruction, but is limited by lower radiologist performance at very low doses. SSM07-02 Analysis of the Causes of Overuse of Head CT Examinations for the Investigation of Minor Head Trauma W ednesday, Nov. 30 3:10PM - 3:20PM Room: S403B Participants Arkadi Beytelman, MA, Rosh Haayin, Israel (Presenter) Nothing to Disclose Eli Konen, MD, Ramat Gan, Israel (Abstract Co-Author) Research Consultant, RadLogics Inc Dan Greenberg, Beer Sheva, Israel (Abstract Co-Author) Nothing to Disclose Eyal Zimlichman, Ramat Gan, Israel (Abstract Co-Author) Nothing to Disclose Eyal Klang, Ramat Gan, Israel (Abstract Co-Author) Nothing to Disclose PURPOSE Minor head injury is a common cause for emergency CT. There are known protocols in assessing the need for CT in minor head injury. One of the most recognizable protocols is the Canadian CT Head Rule (CCHR). The purpose of this study was to estimate the volume and rate of CTs performed in the emergency department of a large tertiary hospital that are unwarranted by CCHR criteria and to analyze factors that contribute to unnecessary examinations. METHOD AND MATERIALS One thousand brain CT scans performed due to minor head injury during 2014 were randomly collected.Medical records were assessed for the following parameters: whether the CT referral met the CCHR criteria, type of the referring physician (emergency physician, internal medicine, surgery, neurologist, other), seniority of the referring physician (beginning resident, experienced resident, senior), cause of head trauma (four wheels motor vehicle accident, two wheels accident, fall accident, etc.). RESULTS A total of 955 cases were included in the analysis of which 104/955 (10.9%) examinations were unjustified by the CHCR criteria. In patients younger than sixty five, 104/279 (37.3%) of the examinations were unjustified. When assessing contributing factors, we found that neurologists conducted more unwarranted CTs (odds ratio 3.5, p=0.011) while surgeons tended to order less (odds ratio 0.676, p=0.126). There was no statistically significant difference between the seniority of the referring physician and over referral. The type of injury that was found to cause the most unjustified CTs was involvement in a four wheels motor vehicle accident (odds ratio 3.034, p<0.001). CONCLUSION The study demonstrates excess use of CTs due to minor head injuries that are not justified by CCHR criteria, especially in the younger patients with an excess of 37.3%. Contributing factors are the type of the referring physician and the type of injury. CLINICAL RELEVANCE/APPLICATION CT overuse cause both unnecessary radiation exposure and waste of healthcare resources. Analysis of the causes for overuse can be implemented both for specific education programs and also for implementation of computerized referring protocols that can help as decision support. SSM07-03 Comparing CT/MRI Diagnostic Accuracy in Posterior Fossa Strokes, Analyzing Diagnostic Yield in Patients with Localizing Symptoms W ednesday, Nov. 30 3:20PM - 3:30PM Room: S403B Awards Student Travel Stipend Award Participants Manav Bhalla, MD , Milwaukee, WI (Presenter) Nothing to Disclose Andrew P. Klein, MD, Pewaukee, WI (Abstract Co-Author) Nothing to Disclose John L. Ulmer, MD, Milwaukee, WI (Abstract Co-Author) Stockholder, Prism Clinical Imaging, Inc Medical Advisory Board, General Electric Company Sarika Pamarthy, MBBS, MS, Columbus, OH (Abstract Co-Author) Nothing to Disclose Kieran E. McAvoy, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Brian Fitzsimmons, MD, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Leighton P. Mark, MD, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Stephen A. Quinet, MD, Milwaukee, WI (Abstract Co-Author) Nothing to Disclose Namrata Bhalla, Brookfield, WI (Abstract Co-Author) Nothing to Disclose PURPOSE Cerebellar and brain stem strokes present with diverse symptomatology and often may not present with the classic stroke symptom of unilateral weakness. Patients presenting with dizziness, vertigo, ataxia/gait disturbances, often receive suboptimal stroke imaging. Our study analyzes distribution patterns in CT and MRI accuracy in posterior fossa stroke to identify possible causes of under diagnosis and pitfalls in ED stroke screening protocols. Formulating refined clinical filters in the decision tree will improve effective use of imaging and patient outcomes. METHOD AND MATERIALS 77/500 patients (of 1000 planned in this ongoing retrospective institutional study) presented with posterior fossa symptoms including dizziness, vertigo, ataxia and gait disturbances. CT/MRI imaging was performed within a 24-hour interval. The accuracy, positive (PPV) and negative (NPV) predictive values of final CT/MRI interpretations were calculated using final clinical discharge diagnosis as the gold standard. RESULTS Overall, 42/500 patients had posterior fossa strokes which were all identified by MRI; 11 presented within the 0-4.5 hr tPA window period (only 1 CT positive, i.e. 9%), 6 within 4.5-24 hrs period (1 CT positive, i.e. 17%) and 25 after 24 hours (7 CT positive, i.e. 28%) of presentation. Amongst the patients presenting with localizing symptoms, 26/77 (33%) patients had stroke (compared to overall stroke incidence of 47.7%). Half of these strokes were located in cerebellar and/or brain stem, where CT is only 21% sensitive. If this happens to be in 0-4.5 hrs period, it further drops to 9%. MRI is highly sensitive and superior to CT, in accuracy and predictive value, across different time frames and symptom profiles. CONCLUSION Appropriate patient selection and robust clinical filters will improve quality of CT/MRI stroke evaluation of the posterior fossa. MRI has greater diagnostic value, especially in CT negative patients with unresolved symptoms. Other confounding factors that favor use of MRI include symptom overlap with varying territory of involvement and the need to rule out non-vascular etiology. CLINICAL RELEVANCE/APPLICATION Preferential utilization of MRI may be justified in critical posterior fossa strokes where there is significant risk of a missed diagnosis/mortality. SSM07-04 Eliminating Medical Waste: Unnecessary Head CTs in Healthy Adults W ednesday, Nov. 30 3:30PM - 3:40PM Room: S403B Awards Trainee Research Prize - Resident Participants Douglas T. Hidlay Jr, MD, Providence, RI (Presenter) Nothing to Disclose Jin K. Jung, MD, Providence, RI (Abstract Co-Author) Nothing to Disclose Matthew R. Shalvoy, MD, Cumberland, RI (Abstract Co-Author) Nothing to Disclose Brian L. Murphy, MD, Barrington, RI (Abstract Co-Author) Nothing to Disclose PURPOSE To examine the diagnostic yield of brain imaging in adults without trauma presenting to the emergency room. METHOD AND MATERIALS All brain computed tomography (CT) examinations performed at our institution as part of an emergency room (ER) visit during 2015 for patients age 18-40 were reviewed (n = 3302). Exclusion criteria were pregnancy or within 2 weeks postpartum, head trauma within the previous two weeks, prior known intracranial pathology and/or procedure, and referral based on outpatient imaging. In the end, 685 cases met inclusion criteria and were reviewed for positive findings. For each study, the patient's demographics and a brief clinical history were recorded, including presenting complaint(s), Glasgow Coma Scale (GCS), and both prior and subsequent imaging findings. RESULTS Nineteen cases had positive intracranial findings (2.8%). Their chief complaints were altered mental status (9), new/unevaluated seizures (5), hemiplegia (3), and progressive focal visual deficits (2). If a patient was GCS 15 at time of presentation without hypertensive emergency/urgency, a new/unevaluated seizure disorder, visual changes, or hemiplegia, their CT scan was negative. In absence of a known malignancy or hypertensive urgency/emergency, a prior negative CT brain examination also had a NPV of 100%. CONCLUSION During 2015, 685 head CTs performed in patients 18-40 years old presenting to the ER without trauma yielded 19 positive results, translating to a diagnostic yield of 2.8%. If CTs were only performed for patients with a GCS of 14 or less, hypertensive urgency/emergency, new/unevaluated seizures, persistent visual deficits, or hemiplegia, 579 head CTs (85%) could have been omitted without missing any of the 19 positives cases, eliminating substantial healthcare cost and reducing unnecessary radiation exposure to patients. This finding represents a significant opportunity for improving the quality of care delivered in the ER nationwide and warrants further investigation. CLINICAL RELEVANCE/APPLICATION Adults under 40 presenting to the ER without trauma are a low-risk population for intracranial pathology and as many as 85% of brain CTs could potentially be eliminated from the diagnostic work-up. SSM07-05 The Role of Computed Tomography (CT) in Predicting Diplopia in Orbital Blunt Trauma W ednesday, Nov. 30 3:40PM - 3:50PM Room: S403B Participants Michaela I. Cellina, Milan, Italy (Presenter) Nothing to Disclose Caterina Bebbere, Sassari, Italy (Abstract Co-Author) Nothing to Disclose Marcello A. Orsi, MD, Milan, Italy (Abstract Co-Author) Nothing to Disclose Giancarlo Oliva, Milan, Italy (Abstract Co-Author) Nothing to Disclose PURPOSE The management of orbital fracture, in terms of need of surgical repair and timing of surgery, is controversial: the evaluation of diplopia is the most important criterion for planning whether to undertake surgical intervention.Or aim was to determine the orbital CT findings that can be used to predict the development of permanent diplopia in patient with orbital fractures. METHOD AND MATERIALS We retrospectively evaluated CT of all patients presented to our Emergency Department for blunt craniofacial trauma (N=3334) from January 2014 to March 2016, selecting only patient with CT-demonstrated orbital fracture.The following CT variables were assessed: fracture location (medial wall, floor, lateral wall, roof, medial wall + floor, lateral wall +floor, lateral wall + roof, multiple locations), fracture multifocality, bone fragments displacement, extraocular muscle thickening, muscle entrapment, muscle displacement, muscle hooking, intraconal emphysema, extraconal emphysema, intraconal hematoma, extraconal hematoma, fat herniation.All patients underwent complete ophthalmological evaluation and Hess-Lancaster test, in order to establish the presence of diplopia.After performing group comparison with Pearson χ2 test, we derived our prediction model by using logistic regression, with diplopia as the prediction and CT variables as predictors. RESULTS We observed 299 patients (male: 221; female: 78; age range:4-93 years; mean age:46) with orbital fracture due to a blunt trauma, 46 (15.4 %) with a Hess Lancaster test-proven diplopia.The CT variables with statistically significant difference between the group with diplopia and the group without diplopia were as follows: floor fracture (p=.014), bone fragments displacement (p=.001), multifocality (p=.005), muscle thickening (p=.001), muscle entrapment (p<.001), muscle displacement (p<.001), fat herniation (p=.003)The CT variables with significance as predictors of diplopia were: floor location (odds ratio [OR], 2.87; 95% confidence interval [CI]:1.22, 6.73; p=.01), muscle thickening, muscle entrapment (OR, 10.69; 95% CI:3.76, 30.4; p<.001) and muscle displacement (OR, 11.51; 95% CI:3.05, 43.3; p<.001). CONCLUSION The development of persistent diplopia can be predicted on the basis of CT findings after an orbital trauma. CLINICAL RELEVANCE/APPLICATION Such patients should be directed toward early surgical repair in order to re-establish extraocular muscle function. SSM07-06 Blunt External Larynegeal Injuries: Factors that Influence Accurate Prospective Diagnosis with Computed Tomography W ednesday, Nov. 30 3:50PM - 4:00PM Room: S403B Awards Student Travel Stipend Award Participants Sonya Khan, MD, Baltimore, MD (Presenter) Nothing to Disclose Clint W. Sliker, MD, Ellicott City, MD (Abstract Co-Author) Nothing to Disclose Deborah M. Stein, MD, PhD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Elizabeth A. Guardiani, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose PURPOSE Determine accuracy of prospectively diagnosed blunt external laryngeal injury (BELI) with computed tomography (CT). Determine if available clinical history or observation of coexisting facial or cervical injuries on the CT influences diagnostic accuracy. METHOD AND MATERIALS IRB approved, retrospective review of patients who presented to a Level I Trauma Center between January 2000 and September 2015, diagnosed with BELI and imaged with CT. Initial CT reports were reviewed, noting: if BELI was prospectively diagnosed by reporting radiologist, the study indication, and if there were coexisting midfacial/mandible fractures and/or cervical artery or spine injury. Multivariate linear regression analysis (p > 0.05) was used to determine likelihood of prospective CT diagnosis of BELI when history suggesting injury or relevant mechanism was provided relative to when nonspecific history was provided. RESULTS 76 patients met inclusion criteria (age 15-77 years, mean 42.3, SD 15.7). BELI was prospectively diagnosed by CT in 57.89% (44/76) of patients. When history specifying laryngeal injury or anterior neck trauma was available at initial CT interpretation, BELI was prospectively diagnosed in 50% (26/44) and 36% (16/44) of patients, respectively. Frequencies of coexisting injuries were: 36.84% (28/76) midface/mandibular fractures, 13.16% (10/76) cervical spine injuries, and 6.67% (5/76) common or cervical internal carotid artery injuries. Multivariate linear regression analysis shows that clinical history suggesting laryngeal injury was significantly associated with accurate prospective diagnosis, coefficient 0.440222 (p = 0.044, CI [0.0125, 0.8678]). Cervical spine injury was also significantly associated with a positive diagnosis, coefficient 0.4825736 (p= 0.014, CI [0.1008, 0.8642]). CONCLUSION When reviewing CT scans of the cervical region in patients with history of acute blunt trauma, radiologists will accurately diagnose BELI more frequently if provided with a clinical history suggesting a laryngeal injury or if diagnosis is made of a coexisting cervical spine injury. CLINICAL RELEVANCE/APPLICATION Blunt external laryngeal injuries are rare (incidence 0.04-0.06%) but clinically significant injuries for which early intervention can improve outcomes. Early clinical diagnosis can be difficult, thus the radiologist may be first to suspect BELI, rendering it crucial for him/her to understand when risk for BELI is high when reviewing cervical CT’s in post-blunt trauma patients. MSES44 Essentials of Trauma Imaging W ednesday, Nov. 30 3:30PM - 5:00PM Room: S100AB ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 FDA Discussions may include off-label uses. Participants Sub-Events MSES44A Imaging of Pediatric Skeletal Trauma Participants Rutger A. Nievelstein, MD, PhD, Utrecht, Netherlands (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Discuss the important hallmarks of normal development of the pediatric skeleton relevant for the radiological evaluation of skeletal trauma. 2) Learn about the key issues in imaging of pediatric skeletal trauma. 3) Discuss the most important differential diagnoses including non-accidental injury. ABSTRACT Due to differences in anatomy, biomechanics, and physiology, the presentation of traumatic lesions in children will differ from that in adults. This is reflected in the types of fractures specific to the pediatric age group and its healing propensity. Conventional radiography is still the corner stone of imaging in pediatric skeletal trauma, although US, CT and MRI may be used for specific indications such as complex injuries and suspected involvement of ligaments and/or internal articular structures. This lecture will focus on the important hallmarks of normal skeletal development, the age-specific distribution and types of pediatric fractures, as well as several differential diagnostic considerations (including non-accidental injury). Furthermore, imaging strategies in pediatric skeletal trauma will be discussed. Active Handout:Rutger A. J. Nievelstein http://abstract.rsna.org/uploads/2016/16000917/MSES44A HANDOUT.pdf MSES44B Imaging Male Pelvic Trauma Participants Matthew T. Heller, MD, Gibsonia, PA, ([email protected] ) (Presenter) Author, Reed Elsevier; Consultant, Reed Elsevier LEARNING OBJECTIVES 1) List the most common injuries of the male pelvis. 2) Select the most appropriate imaging modality and summarize protocol optimization. 3) Describe the key imaging findings of male pelvic trauma and their role in management. ABSTRACT Emergency imaging plays a critical role in triage of male pelvic trauma patients.Evaluation of testis rupture and other scrotal injuries are accurately assessed with ultrasound. Characterization of bladder rupture as intraperitoneal versus extraperitoneal is efficiently diagnosed with CT cystography. Suspected urethral injuries are best depicted with retrograde urethrography. MR is useful in the evaluation of penile injuries. Choosing the most appropriate imaging modality and protocol optimization are essential components of prompt diagnosis and initiation of treatment. MSES44C Blunt Traumatic Aortic Injuries Participants Ferco H. Berger, MD, Toronto, ON, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Apply and choose the correct imaging protocol after blunt chest trauma. 2) Detect features indicating injury to the aorta after blunt trauma, including more subtle injuries. 3) Explain the trauma mechanisms and associated injuries. 4) Develop confidence in being a team player in the trauma team. ABSTRACT Blunt trauma to the chest can cause injury to the aorta and its major branching arteries. These injuries are still the second most lethal condition in blunt trauma patients, after head injuries, and need urgent detection and treatment. In this presentation, aortic injuries resulting from blunt trauma mechanisms will be discussed. These almost invariably result from high-impact trauma, usually with rapid deceleration forces. Patients sustaining blunt traumatic aortic injury (BTAI) usually have many concomitant injuries, that will distract from scrutinizing the aorta. Advancements in CT protocols, imaging findings, classification systems and practice guidelines dealing with BTAI will be discussed. The goal is to increase confidence in diagnosing BTAI and making recommendations for further treatment, increasing our value in the trauma team. Active Handout:Ferco H. Berger http://abstract.rsna.org/uploads/2016/16001482/mses44c BTAI - handout.pdf http://abstract.rsna.org/uploads/2016/16001482/mses44c BTAI - handout.pdf MSES44D Interventional Radiology in Trauma Patients Participants Brian J. Schiro, MD, Miami, FL, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Learn the role of interventional radiology in the evaluation and treatment of trauma patients. 2) Review the embolization methods in treating traumatic injury. 3) Review indications for IVC filters in trauma patients. ABSTRACT Interventional radiologists have a crucial role in the evaluation and management of trauma patients. Transcatheter arteriography for the diagnosis of traumatic injury has been supplanted by accurate and expedient advanced cross-sectional imaging. However, continued progress in endovascular and percutaneous therapies have propelled interventional radiology to the forefront of trauma care. This discussion will focus on the vital impact that interventional radiology has on the trauma patient and will review various therapeutic techniques and prophylactic interventions. Active Handout:Brian Jason Schiro http://abstract.rsna.org/uploads/2016/16000915/Trauma in IR_Handout.pdf SPSC42 Controversy Session: Emergency Imaging: Is Pain in the Chest a Pain in the Neck? W ednesday, Nov. 30 4:30PM - 6:00PM Room: E450B CA CT ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Charles S. White, MD, Baltimore, MD, ([email protected] ) (Moderator) Consultant, Koninklijke Philips NV LEARNING OBJECTIVES 1) Review the clinical challenges related to diagnosing the cause of acute chest pain in the ED. 2) Describe the role of current imaging techniques in evaluating patients who present with acute chest pain. 3) Discuss the feasibility, advantages, and challenges related to use of coronary CTA to evaluate ED chest pain. 4) Review the advantages and disadvantages of using a triple rule-out vs dedicated coronary CTA protocol to assess acute chest pain. ABSTRACT URL Sub-Events SPSC42A Traditional Strategies Are Still Valuable for Evaluating Acute Coronary Syndromes (ACS) Participants Vasken Dilsizian, MD, Baltimore, MD (Presenter) Research Grant, General Electric Company; Research Grant, Siemens AG LEARNING OBJECTIVES View learning objectives under the main course title. SPSC42B Coronary CT Angiography (CCTA) Improves Over Traditional Strategies for ACS Participants Ricardo C. Cury, MD, Miami, FL, ([email protected] ) (Presenter) Research Grant, General Electric Company; Research Consultant, General Electric Company LEARNING OBJECTIVES 1) Effectively utilize coronary computed tomography angiography (CTA) to properly diagnose, detect and evaluate emergency department patients with acute chest pain or other symptoms suggestive of coronary artery syndrome. 2) Explain the relationship between coronary CTA findings and the clinical outcome of patients with acute chest pain. 3) Utilize the appropriate noninvasive studies to assess risk of acute coronary syndrome. ABSTRACT Coronary computed tomography angiography (CCTA) is a rapid and accurate technique to exclude the presence of CAD. Furthermore, the immediate and future likelihood of cardiac events in patients with no or minimal CAD is extremely low for patients with acute chest pain. In light of these favorable test characteristics, several single-center and more recently, multicenter studies have demonstrated the feasibility, safety, and accuracy of CCTA in the ED to assess chest pain patients. URL SPSC42C Which is Better: Triple Rule-out or Standard CCTA? Participants Charles S. White, MD, Baltimore, MD, ([email protected]) (Presenter) Consultant, Koninklijke Philips NV LEARNING OBJECTIVES View learning objectives under the main course title. SPSC43 Controversy Session: Pelvic Imaging in the Emergency Department: Ultrasound, CT or MRI? W ednesday, Nov. 30 4:30PM - 6:00PM Room: S404CD GU OB CT MR US ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Douglas S. Katz, MD, Mineola, NY, ([email protected]) (Moderator) Nothing to Disclose Mariam Moshiri, MD, Seattle, WA, ([email protected]) (Moderator) Consultant, Reed Elsevier; Author, Reed Elsevier; LEARNING OBJECTIVES 1) To overview the current role of ultrasound, CT, and MR in the imaging of non-pregnant and pregnant women with known or suspected acute pelvic conditions, with an emphasis on evidence-based information and societal guidelines, to discuss the advantages and disadvantages of ultrasound, CT, and MR for imaging the acute female pelvis in several common/relatively common scenarios to overview specific protocols for performing effective and accurate ultrasound, CT, and MR imaging examinations of the acute female pelvis, to discuss current controversies regarding the roles of ultrasound, CT, and MR in the imaging of the acute female pelvis. ABSTRACT URL Sub-Events SPSC43A US Participants Sheila Sheth, MD, Cockeysville, MD, ([email protected]) (Presenter) Nothing to Disclose LEARNING OBJECTIVES View learning objectives under the main course title. ABSTRACT URL SPSC43B CT Participants Ana P. Lourenco, MD, Providence, RI, ([email protected]) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) To review radiation dose associated with current pelvic CT imaging. 2) To describe available strategies for minimizing radiation dose. 3) To identify CT imaging findings in a variety of diagnoses in both pregnant and non-pregnant patients presenting with acute pelvic pain. ABSTRACT In this session, we will review CT radiation dose, associated risks, and strategies to minimize patient dose. Cases will be shown to highlight the diagnostic accuracy of CT in the ED as well as to illustrate how protocols may be optimized depending upon the leading differential diagnosis. URL SPSC43C MRI Participants Christine O. Menias, MD, Chicago, IL, ([email protected]) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Review the Role of MRI in acute Pelvic conditions in the Pregnant and Nonpregnant Patient in Case-Based format. 2) Discuss the role of MRI in evaluating indeterminant lesions at US and CT in acute GYN conditions. ABSTRACT Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Christine O. Menias, MD - 2013 Honored Educator Christine O. Menias, MD - 2014 Honored Educator Christine O. Menias, MD - 2015 Honored Educator Christine O. Menias, MD - 2016 Honored Educator ED004-TH Emergency Radiology Thursday Case of the Day Thursday, Dec. 1 7:00AM - 11:59PM Room: Case of Day, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON (Presenter) Nothing to Disclose Douglas S. Katz, MD, Mineola, NY (Abstract Co-Author) Nothing to Disclose Christina A. LeBedis, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose David Dreizin, MD, Baltimore, MD (Abstract Co-Author) Nothing to Disclose Manickam Kumaravel, MD, FRCR, Houston, TX (Abstract Co-Author) Nothing to Disclose Constantine A. Raptis, MD, Saint Louis, MO (Abstract Co-Author) Nothing to Disclose David D. Bates, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thomas Battey, Timonium, MD (Abstract Co-Author) Nothing to Disclose Nicholas M. Beckmann, MD, Houston, TX (Abstract Co-Author) Nothing to Disclose TEACHING POINTS 1) Recognize key imaging findings on multimodality imaging of emergency/trauma patients. 2) Develop differential diagnosis based on the clinical information and imaging findings. 3) Recommend appropriate management including image-guided interventions. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator SPDL50 RSNA Diagnosis Live™: Musculoskeletal and Emergency Department Imaging-From Sports to Trauma Thursday, Dec. 1 7:15AM - 8:15AM Room: E451B MK MR ER AMA PRA Category 1 Credit ™: 1.00 ARRT Category A+ Credit: 1.00 Participants Eric B. England, MD, Cincinnati, OH, ([email protected] ) (Presenter) Nothing to Disclose Carl C. Flink, MD, Cincinnati, OH (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Identify a variety of common sports injuries utilizing MRI. 2) Review clinical presentations of sports injuries that present to orthopedic clinics and how these presentations can assist in the diagnosis when correlated with imaging. 3) Review a variety of typical and atypical musculoskeletal injuries that present to the Emergency Department. This interactive session will use RSNA Diagnosis Live™. Please bring your charged mobile wireless device (phone, tablet or laptop) to participate. ABSTRACT URL RC608 Updating Your Emergency Radiology Practice Thursday, Dec. 1 8:30AM - 10:00AM Room: E353B CT MR ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 FDA Discussions may include off-label uses. Participants Sub-Events RC608A Improving Imaging Appropriateness Participants Bruce E. Lehnert, MD, Seattle, WA (Presenter) Research support, Koninklijke Philips NV LEARNING OBJECTIVES 1) Discuss the variability in and appropriateness of advanced imaging utilization and address potential sources of variability in practice. 2) Review utilization control strategies and their effectiveness in improving imaging appropriateness, including Clinical Decision Support. 3) Discuss PAMA legislation and its implications for radiology. RC608B Optimizing Emergency Cardiothoracic CT and MR Imaging Protocols Participants Constantine A. Raptis, MD, Saint Louis, MO (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Discuss the key components of CT protocols which are appropriate for thoracic imaging in the emergency department setting. 2) Review indications and protocols for MRI of the thorax in the emergency department setting. 3) Identify potential pitfalls and artifacts which may be encountered on CT and MRI of the thorax which are relevant to imaging in the emergency department. ABSTRACT RC608C Update on Dual-energy CT in the Emergency Department Participants Savvas Nicolaou, MD, Vancouver, BC (Presenter) Institutional research agreement, Siemens AG LEARNING OBJECTIVES 1) Review the basic principles of dual energy CT/Spectral imaging. 2) Discuss novel techniques implemented using dual energy CT in the acute setting including: material characterization/decomposition, bone subtraction, virtual non-contrast, iodine distribution maps, and monoenergetic spectral imaging. 3) To explain the utility of dual energy/spectral imaging in the acute care setting with examples in cardiopulmonary imaging, vascular imaging, intracranial aneurysms and stroke imaging, blunt vascular neck injuries, abdominal imaging and musculoskeletal applications. ABSTRACT RC608D Optimizing Emergency Musculoskeletal CT and MR Protocols Participants Meir H. Scheinfeld, MD, PhD, Bronx, NY, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Identify clinical scenarios where MR or CT would be appropriate for the evaluation of emergency musculoskeletal conditions. 2) Optimize emergency department musculoskeletal CT protocols for detection of pathology. 3) Optimize emergency department musculoskeletal MR protocols for detection of pathology. ABSTRACT SSQ05 Emergency Radiology (Musculoskeletal and Spine Imaging) Thursday, Dec. 1 10:30AM - 12:00PM Room: S405AB MK CT MR ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 FDA Discussions may include off-label uses. Participants Clint W. Sliker, MD, Ellicott City, MD (Moderator) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Moderator) Institutional research agreement, Siemens AG Sub-Events SSQ05-01 Evaluating the AAST Clinical Decision Rule for Thoracolumbar Spine Evaluation after Blunt Trauma in a Large Level 1 Trauma Center-Is it as Effective as Screening Imaging? Thursday, Dec. 1 10:30AM - 10:40AM Room: S405AB Participants Enrique Rodriguez, MD, Detroit, MI (Presenter) Nothing to Disclose Brent D. Griffith, MD, Troy, MI (Abstract Co-Author) Nothing to Disclose Britton J. Carter, MD, Detroit, MI (Abstract Co-Author) Nothing to Disclose Feras Mossa-Basha, MD, Detroit, MI (Abstract Co-Author) Nothing to Disclose Stephen Zintsmaster, MD,MPH, Royal Oak, MI (Abstract Co-Author) Nothing to Disclose Suresh C. Patel, MD, Detroit, MI (Abstract Co-Author) Nothing to Disclose Todd Williams, MD, Detroit, MI (Abstract Co-Author) Nothing to Disclose Phyllis Vallee, MD, Detroit, MI (Abstract Co-Author) Nothing to Disclose PURPOSE Injuries to the thoracic and lumbar (TL) spine due to blunt trauma are a common cause for presentation to emergency departments (ED). In 2015, the American Association for the Surgery of Trauma (AAST) published a prospectively derived clinical decision rule for thoracolumbar spine evaluation after blunt trauma. The purpose of this study was to evaluate the accuracy of this decision rule and determine how many TL spine reformats would have been unnecessary had the rule been prospectively applied. METHOD AND MATERIALS 1000 consecutive patients who underwent CT Chest, Abdomen, Pelvis (CT CAP) with TL spine reformatted images following blunt trauma were retrospectively reviewed. Patients with penetrating injury, age < 15 yrs, injury > 48 hrs prior to presentation, known TL spine fracture, and those not evaluated by an ED physician were excluded. Clinical and imaging records of the patients were reviewed to identify all AAST decision rule criteria (alert and evaluable, physical exam, high risk mechanism, age > 60 yrs) and determine the presence of TL spine fracture. RESULTS Of the 1000 patients, 900 met study inclusion criteria, of which 66 (7.3%) had TL spine fractures. Of the 900, 535 patients were not evaluable by the AAST decision rule (i.e., not alert and evaluable, C-spine or other distracting injury)(Fig 1). Of the remaining 365 patients, 20 (5.5%) had TL spine fractures. The decision rule correctly identified 17 of these 20 patients with fractures for a sensitivity of 85%, but with a100% sensitivity for fractures requiring surgical management or bracing. Of the 365 patients evaluable by the AAST decision rule, 102 (27.9%) would have met the criteria for not requiring imaging, of which 3 had fractures detected (Fig 2). CONCLUSION The AAST clinical decision rule for TL spine evaluation after blunt trauma identified all fractures of the TL spine requiring surgical management or bracing and would have resulted in a 27.9% reduction in the number of required TL spine reformats. However, the performance of the decision rule in detecting fractures not requiring surgical management or bracing was suboptimal for a screening tool and further evaluation of its accuracy is necessary prior to widespread implementation. CLINICAL RELEVANCE/APPLICATION Fractures not requiring surgical management or bracing can still alter patient management and clinicians utilizing this clinical decision rule must take this into consideration when forgoing imaging. SSQ05-02 Revisiting the ACR Appropriateness Criteria for Acute Midfoot Fractures: 5-Year Study of Limitations of Radiography in 400 Patients Thursday, Dec. 1 10:40AM - 10:50AM Room: S405AB Awards Student Travel Stipend Award Participants Mohammad Mansouri, MD, MPH, Boston, MA (Presenter) Nothing to Disclose Renata R. Almeida, boston, MA (Abstract Co-Author) Nothing to Disclose Michael H. Lev, MD, Boston, MA (Abstract Co-Author) Consulant, General Electric Company; Institutional Research Support, General Electric Company; Stockholder, General Electric Company; Consultant, MedyMatch Technology, Ltd; Consultant, Takeda Pharmaceutical Company Limited; Consultant, D-Pharm Ltd Ajay K. Singh, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Efren J. Flores, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE Midfoot fractures are missed in 20%of initial visits.Missing midfoot fractures can cause pain, pseudoarthrosis,arthritis,deformity and amputation.Our aim is to analyze Lisfranc and Chopart fractures and to provide an evidence-based flowchart to reduce missed fractures. METHOD AND MATERIALS This is a HIPAA compliant,IRB approved,retrospective study conducted between 2010 and2014.PACS system of our institution was searched for Lisfranc and Chopart fractures.Diagnosis was made based on imaging modalities.Patients were divided into 2categories:high-energy(motor vehicle accidents,fall from height)and low-energy trauma(slips and twisting,simple fall,blunt trauma)based on medical records. RESULTS 400 patients were analyzed(mean 46.5 years;54.3% male).Lisfranc fracture was diagnosed in 65.0%(260/400), Chopart in 33.3% (133/400) and 1.8%(7/400)had both.The most common associated fracture was fibular diaphysis (8.5%;34/400).CT had the highest overall sensitivity (98.5%;203/206),followed by MRI (98.3%;58/59),weight bearing radiography (81.3%;65/80)and plain radiography (79.7%;286/359).Overall, CT and MRI were significantly more sensitive than plain radiography and weight bearing radiography(all p<0.001). Fractures were missed in 19.2%(77/400)of first visits.In missed cases,MRI and CT were significantly more sensitive (97.7% and 92.9% respectively)comparing weight bearing radiography(42.9%)and plain radiography (18.1%)(all p<0.05).Most common trauma history was low-energy (66.0%;264/400).Low-energy trauma cases were significantly missed more than highenergy trauma (p=0.04). In low-energy trauma,plain radiography and weight bearing radiography had the sensitivity of 77.5%and 80.3%respectively.CT and MRI are next steps and significantly more sensitive (99.1% and 98.0%respectively;both p<0.001).In high-energy trauma,first step is plain radiography (82.9%sensitive)followed by CT which is significantly more sensitive(97.9%;p<0.001). CONCLUSION Lisfranc and Chopart fractures were missed in the first presentation in19.2%of patients.Overall,CT and MRI were more sensitive to detect these fractures.If radiographs are negative in the first visit and clinical suspicion remains for midfoot fracture,CT or MRI are both equally efficient for the diagnosis of midfoot fractures. CLINICAL RELEVANCE/APPLICATION This study provides an opportunity to reassess imaging appropriateness of acute midfoot fractures to reduce delayed diagnosis that negatively impact patient care SSQ05-03 The (Lack of) Impact of Published Guidelines on Appropriate Imaging for Low Back Pain in the Emergency Department Thursday, Dec. 1 10:50AM - 11:00AM Room: S405AB Awards Student Travel Stipend Award Participants Sarvenaz Pourjabbar, MD, New Haven, CT (Presenter) Nothing to Disclose Ali Raja, MD, MBA, Boston, MA (Abstract Co-Author) Nothing to Disclose Ivan Ip, MD, MPH, Brookline, MA (Abstract Co-Author) Nothing to Disclose Ramin Khorasani, MD, Boston, MA (Abstract Co-Author) Consultant, Medicalis Corp PURPOSE To quantify the impact of a Clinical Practice Guideline for imaging of patients with low back pain (LBP) (published by the American College of Physicians and the American Pain Society in 2007) on imaging practices in the emergency department (ED). METHOD AND MATERIALS Informed consent was waived for this IRB-approved retrospective observational study. ICD-9 diagnosis codes were used to fetch ED visits related to low back pain in patients 18-64 years old in two 2-year periods: 2005/2006 (just before the guideline was published) and 2013/2014 (5 years after the guideline was published). Imaging performed within 24 hours of the ED admission was considered related to that visit. As per the guideline, each imaging indication was linked to specific diagnosis and procedure codes (ICD-9/CPT) which was used to confirm appropriateness of the imaging. In order to verify the accuracy of ICD-9/CPT method, 160 charts were randomly selected from the study cohort and manually reviewed. The primary outcome was the overall utility of imaging and the secondary outcome was the proportion of inappropriate imaging. Chi-square test was used to compare the pre and post guideline publication groups. RESULTS In 2005/2006, 3,221 unique ED visits (age: 40.4 ± 10, F:M 1235:1986 ) were due to low back pain, compared to 3,766 in 2013/2014 (age: 42.5 ± 12, F:M 1621:2145 ). Chart review of 160 charts showed a sensitivity and specificity of 89% & 96% using the ICD-9/CPT codes. The use of cross-sectional imaging for these patients increased from 46% to 58% over the two time periods (p=0.0001), however, the proportion of imaging not adherent to the guidelines remained the same (61%, p-value= 0.6). In patients with imaging indicated by the guideline, 29.8% (337/960) in 2005-2006 and 42% (412/986) in 2013-2014 had imaging performed (p=0.002). CONCLUSION The implementation of the guideline resulted in an overall increase in imaging, primarily due to an increase in the amount of imaging of patients who met appropriate guideline criteria. Inappropriate imaging did not decrease; suggesting that guideline publication alone is unlikely to change image-ordering behavior CLINICAL RELEVANCE/APPLICATION Publication of a Clinical Practice Guideline for low back pain imaging has not optimized imaging use. Publication of a Clinical Practice Guideline for low back pain imaging has not optimized imaging use. SSQ05-04 Is MR of the C-spine in Acute Trauma Patients Indicated? Thursday, Dec. 1 11:00AM - 11:10AM Room: S405AB Participants Marlen Pajcini, MD, San Jose, CA (Presenter) Nothing to Disclose Mahesh R. Patel, MD, San Jose, CA (Abstract Co-Author) Nothing to Disclose Rajul P. Pandit, MD, San Jose, CA (Abstract Co-Author) Nothing to Disclose John Sherck, MD, San Jose, CA (Abstract Co-Author) Nothing to Disclose Adella Garland, San Jose, CA (Abstract Co-Author) Nothing to Disclose Young S. Kang, MD, San Jose, CA (Abstract Co-Author) Nothing to Disclose PURPOSE In recent years, MR of the cervical spine has become part of the routine imaging protocol for selected indications in many trauma centers. Because of the expense and complex operational requirements of MR, it is imperative to establish its effectiveness. While there is ample anecdotal evidence and some clinical series demonstrating the utility of MR, we set out to examine the spectrum and frequency of findings in MR performed on patients presenting to our Level I trauma center. METHOD AND MATERIALS A retrospective review of consecutive C-spine MR imaging studies over a two-year period ordered in the context of an acute trauma was performed. Each study was assessed for the presence of the following findings: cord injury, ligamentous injury, soft tissue/muscle injury, marrow/disc injury, and/or vascular injury. If none of these acute findings were present or if the MR study demonstrated only findings that were seen on prior imaging studies, the study was categorized as negative for the purposes of the analysis. RESULTS 241 studies were identified. Indications included neurologic deficit or inability to perform clinical assessment. Cord injury was noted in 17% (41/241), ligamentous injury in 43% (104/241), soft tissue/muscle injury in 29% (69/241), marrow/disc injury in 28% (67/241), and vascular injury in 12% (28/241). 36% (86/241) of the analyzed studies were negative for acute findings or only demonstrated findings that were previously known from prior imaging. CONCLUSION Ligamentous injury is the most common pathological finding in MR. Cord injury, which can have the most severe clinical repercussions, was the least frequent finding at 17%. Slightly over one-third of analyzed cases were negative for any acute findings or demonstrated findings that had been previously described. This indicates that in the majority of trauma patients for which a C-spine MR study is ordered, an acute finding is generally present. While there may be variations in treatment protocols among trauma centers in response to specific findings on MR, the overall high frequency of positive findings found in our study validates the general concept of the use of MR in acutely injured patients who demonstrate neurologic deficit or cannot be assessed clinically. CLINICAL RELEVANCE/APPLICATION Understanding the frequency of findings on C-spine MR imaging studies on acute trauma patients can allow radiologists to guide ordering physicians in appropriate utilization. SSQ05-05 The Impact of Total Spine MRI on Targeted Patient Selection for Surgical Therapy of Geriatric Vertebral Fractures Thursday, Dec. 1 11:10AM - 11:20AM Room: S405AB Participants Christoph Weber, MD, Hamburg, Germany (Presenter) Nothing to Disclose Corinna Ossadnik, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose Theo Abel, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose Jonas Hafner, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose Hannah Hentschel, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose Peter Bannas, MD, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose PURPOSE To assess the diagnostic accuracy of total spine MRI in the diagnosis of vertebral fractures in comparison to conventional radiographs (CR) and to evaluate its effect on surgical therapy (vertebro-/kyphoplasty, spondylodesis etc.) in geriatric patients. METHOD AND MATERIALS The vertebral bodies (n=2736) of 114 "geriatric" patients, average age 84y (75-96y) were measured by the method of Genant on total spine MRI and CR performed on average within 2d (0-17d) before to determine morphology (normal, wedge, biconcave, crush) and to graduate deformity."Geriatric" was defined as age >75y. All patients suffered from back pain after mild trauma. Two radiologists independently evaluated the images (T1/T2/STIR sequences). Interobserver agreement was assessed by kappa statistics. Surgical treatment was indicated, when the fracture was fresh (fluid sign on edema sensitive STIR sequence, fracture line), the patient had <5 total fractures and the posterior border was involved. RESULTS Qualitatve analysis revealed n=520/2736 vertebral bodies fractured, quantitatve analysis by the method of Genant increased the amount of vertebral fractures/deformities to n=1062/2736. The presence of a fluid sign on STIR sequences and a fracture line indicated the recentness of the vertebral fracture in 7% (n=202/2736) of vertebral bodies measured. 38 % (n=78//202) of these recent fractures were missed on CR (p=0.019), 7 % (n=14/202) were distant from the location of pain and not imaged by CR. The method of Genant revealed a reduction of heights in deformed vertebral bodies of ~3 mm, either on CR and MRI. Surgical therapy was indicated in 53% (n=60/114) patients, 55% (n=33/60) rejected the recommended surgical intervention, 18% underwent vertebro-/kphoplasty, 6% spondylodesis. Surgical therapy was predominantly indicated based on MRI data. κ-scores for interobserver agreement for existing fractures were as follows: MRI, κ = 0,754; CR, κ = 0,488; for posterior border involvement, respectively: MRI, κ = 0,718; CR, κ = 0,567. CONCLUSION Interobserver agreements were much better for MRI than for CR. For an accurate selection of patients with vertebral fractures for surgical therapy after mild trauma total spine MRI represents a significant improvement to detect recent vertebral fractures in geriatric patients. CLINICAL RELEVANCE/APPLICATION Total spine MRI is the method of choice to detect vertebral fractures and to select vertebral fractures for surgical therapy in geriatric patients. SSQ05-07 140 kVp Spectral Filtration CT of the Lumbar Spine: Reduced Radiation Dose in the Emergency Setting Thursday, Dec. 1 11:30AM - 11:40AM Room: S405AB Awards Student Travel Stipend Award Participants Sheldon J. Clark, MD, Vancouver, BC (Presenter) Nothing to Disclose Bo Gong, MSc, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Patrick J. Slipp, MD, Vancouver, BC (Abstract Co-Author) Nothing to Disclose Michael E. O'Keeffe, MBBCh, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG Savvas Nicolaou, MD, Vancouver, BC (Abstract Co-Author) Institutional research agreement, Siemens AG Patrick D. McLaughlin, FFRRCSI, Vancouver, BC (Abstract Co-Author) Speaker, Siemens AG PURPOSE Imaging of the lumbar spine is often indicated in symptomatic patients who have undergone low velocity trauma. The purpose of this study is to compare image quality and diagnostic accuracy of a conventional 120 kVp CT with a 140 kVp CT with tin filter in acute trauma patients. A 140 kVp with tin filter CT can be obtained at 1/3 of the dose of a conventional 120 kVp CT. METHOD AND MATERIALS Institutional review board approval was obtained, with no informed consent required, for this retrospective analysis. 97 consecutive trauma patients underwent abdominal scans using a dual source, dual energy 128-slice CT system (Definition FLASH; Siemens Healthcare, Forchheim, Germany). Image noise, spatial resolution, contrast resolution, diagnostic acceptability, and diagnostic accuracy for fractures/soft tissue injuries were compared between the conventional 120 kVp CT (mixed data set) and the 140 kVp with tin filter CT (single data set) using a 10 point scoring system (1=unacceptable, 5=acceptable, 10=excellent). These parameters were reviewed by two radiologists. Analysis between the two CT data sets were analyzed using one-way paired-ttests. RESULTS The average radiation dose for the conventional 120 kVp CT was 6.1 +/- 2.3 mSv. The 140 kVp with tin filter CT is approximately 1/3 of the dose, and would be 2 mSv. Image noise, spatial resolution, contrast resolution, diagnostic acceptability, and diagnostic accuracy were well matched between the two readers. There were statistically significant (p<0.05) decreases in image noise (9.7+/-0.5 vs. 8.4 +/-0.9), spatial resolution (9.6+/-0.6 vs. 8.4+/-1.0), contrast resolution (9.3+/-0.8 vs. 8.0+/-1.0), and diagnostic acceptability (9.97 +/- 0.17 vs. 9.91+/-0.29). No fractures or soft tissue injuries were missed in either data sets. CONCLUSION No fractures or soft tissue injuries were missed on the 140 kVp with tin filter CT when compared with the conventional 120 kVp CT. While image quality was statistically decreased, all parameters were within the range of acceptability. These results suggest that in specific cases, an ultra low dose lumbar spine imaging protocol can be performed at 1/3 of the conventional dose. CLINICAL RELEVANCE/APPLICATION The ability to acquire a CT examination of the lumbar spine at approximately 1/3 of the conventional dose with no degradation in image quality or reduction in diagnostic accuracy for vertebral body fracture or soft tissue injury is a substantial benefit. SSQ05-08 Is Tomosynthesis More Accurate than Radiography in Detecting Subtle Hip Fractures? Thursday, Dec. 1 11:40AM - 11:50AM Room: S405AB Participants Naveen Parasu, MBBS, Hamilton, ON (Presenter) Nothing to Disclose Jane Castelli, Hamilton, ON (Abstract Co-Author) Nothing to Disclose Sandra Monteiro, PhD, Hamilton, ON (Abstract Co-Author) Nothing to Disclose David A. Koff, MD,FRCPC, Hamilton, ON (Abstract Co-Author) Stockholder, Real Time Medical, Inc Spouse, President, Real Time Medical, Inc Katelyn Nye, Waukesha, WI (Abstract Co-Author) Employee, General Electric Company John M. Sabol, PhD, Waukesha, WI (Abstract Co-Author) Employee, General Electric Company PURPOSE Digital tomosynthesis with flat-panel detector radiography is a novel application that allows easy, swift volume data acquisition of any anatomical site of interest with arbitrary patient posture. A single sweep of the X-ray tube provides multiple tomographic images of high resolution giving superior anatomical detail, potentially demonstrating fractures not identified on radiographs. The purpose of this study is to demonstrate that using digital tomosynthesis, in conjunction with radiographs, is better at detecting subtle and occult hip fractures than radiographs alone. METHOD AND MATERIALS This was a prospective 8-month study that assessed adult patients presenting to ER with a suspected hip fracture following a fall. For study purposes, a hip fracture was defined as involving either proximal femur or pelvis. Patients with prior hip fractures or surgery were excluded from study. 62 patients (M=24; F=38; average age=79 yrs) without an obvious hip fracture on radiographs (as determined by the technologist) proceeded immediately to tomosynthesis. Images were reviewed by musculoskeletal radiologists. RESULTS Of the 62 patients, 15 had hip fractures confirmed by either surgery or medical treatment. CT confirmed fracture in 3 patients.The fracture location and corresponding patient numbers were as follows: Femoral neck/intertrochanteric region (5); acetabulum (5); pubic rami (4); sacral ala (1). 6 patients (5 femoral and 1 acetabular fracture) had surgical management.Radiographs showed fracture in 8 of the 15 patients with no false positive cases (sensitivity=53%; specificity=100%). Tomosynthesis detected all 15 fractures with no false positive cases (sensitivity and specificity were both 100%).Among the 47 patients with no fractures, 3 had CT while 2 had MRI, which confirmed no evidence of bony trauma. The remaining 42 patients had their medical records reviewed 30 days following their initial ER visit and discharge, which confirmed no further admissions from the initial hip injury. CONCLUSION The study shows that tomosynthesis is an accurate imaging modality in detecting subtle, nondisplaced hip fractures which may not be readily apparent on initial radiographs. CLINICAL RELEVANCE/APPLICATION Digital tomosynthesis provides an early and accurate diagnosis of hip fractures, particularly in centers where CT or MRI is not readily available and is also significantly less expensive. SSQ05-09 Systematic Radiation Dose Reduction in Cervical Spine Computed Tomography of Human Cadaveric Specimens - How Low Can We Go? Thursday, Dec. 1 11:50AM - 12:00PM Room: S405AB Participants Anna Hirschmann, MD, Basel, Switzerland (Presenter) Nothing to Disclose Dorothee Harder, Basel, Switzerland (Abstract Co-Author) Nothing to Disclose Clemens Reisinger, MD, Basel, Switzerland (Abstract Co-Author) Nothing to Disclose Johanna Lieb, Basel, Switzerland (Abstract Co-Author) Nothing to Disclose Zsolt Szucs-Farkas, MD, PhD, Berne, Switzerland (Abstract Co-Author) Nothing to Disclose Sebastian T. Schindera, MD, Basel, Switzerland (Abstract Co-Author) Research Grant, Siemens AG; Research Grant, Ulrich GmbH & Co KG; Research Grant, Bayer AG; Speakers Bureau, Bayer AG Magdalini Tozakidou, MD , Basel, Switzerland (Abstract Co-Author) Nothing to Disclose PURPOSE To compare image quality of computed tomography (CT) images of the cervical spine of cadaveric specimens at different radiation dose levels reconstructed with a filtered back projection (FBP) and an iterative reconstruction (IR) algorithm. METHOD AND MATERIALS The cervical spine of four human formalin-fixated cadavers (mean BMI; 30.5 kg/m2 ± 5.2; range 24-36) was examined using a 128MDCT scanner (DefinitionAS/Siemens) at nine different reference tube current-time products (45/ 75/ 105/ 135/ 150/ 165/ 195/ 275/ 355 mAs) and a tube voltage of 120 kVp. Automatic tube current modulation was applied (CareDose 4D). Data were reconstructed using both FBP and IR (SAFIRE/Siemens; strength 3). Morphological characteristics (vertebral cortex, anterior/posterior vertebral integrity, conspicuity of trabecular bone, posterior vertebral alignment, facet joint alignment) were quantified on a Likert-scale for each cervical segment by four independent and blinded radiologists. Subjective image noise was evaluated on a three-point scale. Signal-to-noise ratio (SNR) was measured. Statistical analysis included analysis of variance and Tukey’s-test. RESULTS IR provided significantly better image quality than FBP (P<0,001); noise increased as radiation dose decreased. Subjective image noise at levels C1-C4 was rated as either “no noise” or as “acceptable noise” in all scans. At lower spine levels subjective image noise was not acceptable, even at 355 mAs. Shoulder position of all human cadaveric specimens was found to be at level C5. Analyzing all spinal levels, scores for morphological characteristics revealed no significant differences between 105 and 355 mAs (P=0,555), but were significantly worse in scans at lower 45 (P < 0,001) and 75 mAs (P=0,025). CONCLUSION Clinically acceptable image quality of the cervical spine of cadaveric specimens with different body habitus can be achieved with reference mAs of 105. High position of the shoulders is a limiting factor even with high radiation doses; therefore pulldown of both shoulders during acquisition is fundamental. CLINICAL RELEVANCE/APPLICATION Radiation dose for cervical spine CT may be significantly reduced in patients with a low shoulder position. ERS-THA Emergency Radiology Thursday Poster Discussions Thursday, Dec. 1 12:15PM - 12:45PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Clint W. Sliker, MD, Ellicott City, MD (Moderator) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Moderator) Institutional research agreement, Siemens AG Sub-Events ER238-SDTHA1 Clinical Relevance of Consecutive CT Scans for the Evaluation and Monitoring of Geriatric Pelvic Fractures Station #1 Participants Christoph Weber, MD, Hamburg, Germany (Presenter) Nothing to Disclose Peter Bannas, MD, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose Wolfgang Lehmann, MD, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose Thies H. Schroeder, MD, Hamburg, Germany (Abstract Co-Author) Nothing to Disclose PURPOSE To evaluate consecutive computed tomography (CT) imaging in fragility fractures of the pelvis (FFP) in geriatric patients and to prove its effect on the indication for surgical stabilisation treatment. METHOD AND MATERIALS 60 CT Scans of 29 consecutive patients >75y (mean age 83,8±7,8y, 27f/2m) with a history of low impact energy trauma and confirmed pelvic fracture, who had received CT for fracture evaluation and at least one consecutive CT for follow up during the following month after pain adapted ambulation, were evaluated. Pelvic fractures were classified according to the system established by Rommens/Hofmann for fragility fractures of the pelvis. The Barthel ADL index was used as a measure of physical disability after admittance. RESULTS Follow up CT was acquired 14±4,6 days after initial CT. Isolated fractures of the anterior pelvic ring (FFP Type Ia,b) were initially detected in 13,8% (n=4) of patients. Combined fractures of the anterior and posterior pelvic ring with moderate instability (FFP Type IIa,b,c) accounted for 65,5% (n=19), higher (FFP Type IIIa,b,c) for 3,4% (n=1) and highest instability (FFP Type IVa,b,c) for 17,2% (n=5). 10 patients (34,5%) deteriorated in fracture classification during follow up (3 patients within one category, 4 patients deteriorated by one category, and 3 patients by two categories). There was no significant difference in age or physical disability between patients that showed fracture deterioration and those that did not. CONCLUSION Aggravation of fractures in over a third of patients may indicate that a more aggressive, surgical approach is needed in the management of FFP in the elderly. A progressive surgical approach for FFP IIb+ fractures of the anterior and posterior pelvic ring may prevent aggravation, e.g.by sacro-iliacal screw osteosynthesis. CLINICAL RELEVANCE/APPLICATION Conventional Radiography is insufficient in detecting fragility fractures of the pelvis in geriatric patients. CT is mandatory for the initial grading with FFP-Classification and to indicate and plan surgical stabilisation therapy, e.g.by sacro-iliacal screw osteosynthesis. ER239-SDTHA2 Mild Traumatic Brain Injury (MTBI): Screening Computerized Tomography(CT)?Utility of Clinical Guidelines in a Tertiary Referral Hospital in Spain Station #2 Participants Susana Manso Garcia, DDS, valladolid, Spain (Presenter) Nothing to Disclose Maria J. Velasco-Marcos Sr, MD, PhD, Valladolid, Spain (Abstract Co-Author) Nothing to Disclose Santiago Marzoa Ruiz, Valladolid, Spain (Abstract Co-Author) Nothing to Disclose Marta Moya de la Calle, Valladolid, Spain (Abstract Co-Author) Nothing to Disclose Arnold Antonio Montes Tome, Valladolid, Spain (Abstract Co-Author) Nothing to Disclose PURPOSE To analyze two available prognostic tools sus as the Canadian standard(CT) and New Orleans(NO),both internationally accepted,in order to avoid unnecessary TC.To asses their applicability to decision making in the diagnosis of MTBI. METHOD AND MATERIALS Cross-sectional study in Emergency department of a tertiary hospital in patients with diagnosis of MTBI.SPSS20.0 computer program was used to analyze the variables: demographic,clinical,classification,diagnostic management,complementary test,results and CT and NO criteria.CT was performed to 308 out of 1329 patients with MTBI(23,17%).The data from these 308 patients who were submitted to CT as additional proof were analyzed,showing that 47,4% of the applications did meet NO criteria for CT and 73,4%met CT criteria RESULTS The results to CT were normal in 83,4% cases. Amog those in which CT showed pathology,74,5% met CT criteria an 58,8% NO criteria,statistically significant(ES).Among the pathological CT,56,9% patients suffered loss of consciousness and 37,6% were hospitalized.In 58,8% of cases with a pathologic Ct a dangerous mechanic of injury was found as a cause(ES). CONCLUSION Most of the CT requested in patients with MTBI were no pathological.The CT criteria shows greater sensitivity and specify than NO criteria.We haven,t found a relationship between pathological CT and loss of consciousness,however in this groupp a dangerous mechanism of injury is often found a cause. CLINICAL RELEVANCE/APPLICATION The use of clinical guidelines in MTBI avoid unnecessary CT and radiation.CT criteria is better predictor of Clinically Important CT Findings in our study. ER240-SDTHA3 Does Criteria-based Direct Access to Polytrauma Whole-body CT in the Emergency Department lead to Over-scanning? Could Plain Radiography have a Role in Selection of Patients for CT? Exploring a Delicate Interplay between Specificity and Sensitivity Station #3 Participants Oliver Duxbury, MBBCh, BSc, Brighton, United Kingdom (Abstract Co-Author) Nothing to Disclose Nikola Tomanovic, MBBS, Brighton, United Kingdom (Presenter) Nothing to Disclose Ahmed Daghir, MRCP, FRCR, Oxford, United Kingdom (Abstract Co-Author) Nothing to Disclose PURPOSE A set of criteria for direct Emergency Department access to polytrauma whole-body CT scans were introduced in 2013 to help guide clinical decision making and speed up patient imaging in the Emergency Department.This study looks at the use of plain radiographs (XR) prior to CT acquisition and the proportion of “normal” scans, before and after the criteria implementation. METHOD AND MATERIALS A retrospective sample of 60 polytrauma whole-body CT scans, performed over a 2 month period, at a major trauma centre was analysed in 2012, 2014 and 2015.We compare the proportion of patients undergoing XR of the chest or pelvis prior to whole body CT, as well as the proportions of XR and CT studies reported as negative for acute injury, before (2012) and after (2014 and 2015) introduction of these criteria. RESULTS The proportion of negative polytrauma whole-body CT scans rose from 27% in 2012, to 33% in 2014, to 47% in 2015.Over the same time period, the proportion of patients undergoing chest XR has decreased from 73% in 2012 to 37% in 2014 and 0% in 2015 and the number undergoing pelvic XR from 60% in 2012 to 25% in 2014 and 2% in 2015.Of the 73% undergoing XR in 2012, 20% of patients had negative XR and CT, 51% had positive XR and CT and 29% had a negative XR but positive CT. 27% of patients had no XR, with 57% having positive and 43% negative CT.Of the 37% undergoing XR in 2014, 33% had negative XR and CT, 38% had positive XR and CT and 28% had a negative XR but positive CT. 63% did not have XR, of which 48% had positive and 52% negative CT. CONCLUSION Our results show how a criteria-based direct Emergency Department access to CT protocol leads to a gradual increase in the numbers of negative CT scans but a dramatic decrease in the use of plain radiographs prior to CT. This suggests a lower threshold for selection of patients who receive whole-body CT.It is not clear from our data, that using plain radiographs to aid clinical judgement for patient selection would increase specificity sufficiently to lead to better outcomes. Further work is needed to better classify the positive CT findings not seen on XR. CLINICAL RELEVANCE/APPLICATION Current data implies that faster access to CT removes the need for plain radiographs to direct urgent intervention for lifethreatening injuries. However, further work is required to ascertain if plain radiographs have a role in patient selection for CT in certain patient subsets. ERS-THB Emergency Radiology Thursday Poster Discussions Thursday, Dec. 1 12:45PM - 1:15PM Room: ER Community, Learning Center ER AMA PRA Category 1 Credit ™: .50 Participants Clint W. Sliker, MD, Ellicott City, MD (Moderator) Nothing to Disclose Savvas Nicolaou, MD, Vancouver, BC (Moderator) Institutional research agreement, Siemens AG Sub-Events ER242-SDTHB1 Radiology Resident Interpretations of Diffusion-weighted MR Imaging in the Emergency Department: Is the Diagnostic Performance Influenced by Level of Residency Training? Station #1 Participants Hye Jin Baek, Changwon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Seung Jin Kim, MD, Basan, Korea, Republic Of (Presenter) Nothing to Disclose Kyungsoo Bae, MD, Changwon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Kyung Nyeo Jeon, MD, Changwon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Dae Seob Choi, BA, Jinju, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Soo Buem Cho, Jinju, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Bo Hwa Choi, Changwon, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Jin Il Moon, MD, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Hwa Seon Shin, Jinju, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose Hyun Kyung Jung, Busan, Korea, Republic Of (Abstract Co-Author) Nothing to Disclose PURPOSE To determine the diagnostic performance of radiology residents interpretations for diffusion-weighted MR imaging (DWI) in the emergency department at different levels of residency training. METHOD AND MATERIALS A total 160 patients who underwent DWI with acute neurologic symptoms were included in this retrospective study with institutional review board approval. Four radiology residents with different training years and one attending neuroradiologist independently assessed the results of DWI. Discordancies between the results of residents and attending neuroradiologist were classified as followings; false-positive (FP) and false-negative (FN). We also evaluated a diagnostic performance of four residents according to the reference standard. All data was analyzed by using Fisher’s exact test, kappa statistics, and ROC analysis. RESULTS Overall, the agreement rate was 84.8% with 15.2% of overall discrepancy rate. All of discrepancies were insignificant. There were 83 FN results. The most common misses were acute focal infarction (n=13), extraparenchymal hemorrhages (n=18), small vessel disease (n=34), diffuse axonal injury (n=7), solitary mass (n=6), osmotic demyelination syndrome (n=2), and postictal change (n=3). There were 14 FP results including hemorrhage and acute infarction. The 4-year resident showed the highest diagnostic performance (Az value: 0.906; 95% CI: 0.850, 0.947; 87.5% of sensitivity; and 93.8% of specificity). The level of training had a significant influence (P < 0.05) on their interpretations. Kappa statistics showed good agreement of results between residents and attending neuroradiologists. CONCLUSION The level of resident training had a significant effect on their diagnostic performance, and there was a good interobserver agreement between the results of residents and attending neuroradiologists. Therefore, radiology residents could safely make the initial interpretation of DWI which underwent in ER, and formal reporting may wait until a suitable experienced radiologist is available. CLINICAL RELEVANCE/APPLICATION Under on-call duty system, radiology residents can make the initial interpretation of emergent DWI safely , and formal reporting may wait until a suitable experienced radiologist is available. ER243-SDTHB2 Fractures of the Foot Sesamoids: 5-year Imaging Efficacy Analysis of an Underdiagnosed Acute Injury Station #2 Participants Mohammad Mansouri, MD, MPH, Boston, MA (Presenter) Nothing to Disclose Renata R. Almeida, boston, MA (Abstract Co-Author) Nothing to Disclose Michael H. Lev, MD, Boston, MA (Abstract Co-Author) Consulant, General Electric Company; Institutional Research Support, General Electric Company; Stockholder, General Electric Company; Consultant, MedyMatch Technology, Ltd; Consultant, Takeda Pharmaceutical Company Limited; Consultant, D-Pharm Ltd Ajay K. Singh, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Efren J. Flores, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose PURPOSE Sesamoid fractures of the foot are uncommon but often missed in the first radiology exam. Missing them can cause pain, nonunion, malunion and avascular necrosis. We aim to analyze sesamoid fractures of our large academic medical center and to investigate sensitivity of imaging modalities in detecting sesamoid fractures. METHOD AND MATERIALS This is a HIPAA compliant, IRB approved, retrospective study. The PACS system of our institution was searched for patients with sesamoid fracture of the foot between 2010 and 2014. Medical records of these cases were investigated for variables. RESULTS Total of 20 patients (13 females, 7 males) were collected with mean age of 37.5 years. 80% of fractures were due to stress fracture or blunt trauma. In 10% of cases (2/20), tight shoes were used at the time of starting the pain. Sesamoid fractures were missed in 55% (11/20) of patients in the first radiology exam; 36.4% of the missed fractures (4/11) were considered as bipartite at first. Fifty percent of patients (10/20) were diagnosed with fibular sesamoid fracture, 45% (9/20) with tibial and 5% (1/20) with fifth sesamoid fracture. MRI had the highest sensitivity (100%; 9/9), followed by weight-bearing film (66.7%; 4/6), and radiography (60%; 9/15). MRI had significantly higher sensitivity comparing radiography (p=0.02). Rate of sesamoid fractures in foot exams was 0.014% (15/104,962) in radiography, 0.268% (6/2242) in weight-bearing film, 0.032% (1/3164) in foot CT, 0.124% (9/7262) in foot MRI and 0.026% (31/117,630) in total foot exams. This represents a ratio of 1 sesamoid fracture for every: 6997 radiographs, 374 weight-bearing films, 3164 foot CTs, 807 foot MRIs and 3795 in total foot exams. 90% of patients (18/20) were treated conservatively, and 10% (2/20) were treated surgically. CONCLUSION Sesamoid fractures occur at a rate of 0.026% in total foot exams, are usually due to stress fracture or blunt trauma and are most commonly treated conservatively. This study showed radiography has a sensitivity of 60.0% in diagnosing sesamoid fractures. MRI has significantly higher sensitivity and is the next step in evaluating patients with normal radiographs. CLINICAL RELEVANCE/APPLICATION Radiography has a low sensitivity in diagnosing sesamoid fractures and MRI is the next step in evaluating patients with normal radiographs. ER244-SDTHB3 Quantitate Analysis of Initial Non-Contrast Computed Tomography in Acute Ischemic Stoke Station #3 Participants Wilson Altmeyer, MD, San Antonio, TX (Abstract Co-Author) Nothing to Disclose Mamie Gao, San Antonio, TX (Abstract Co-Author) Nothing to Disclose Junfei Li, San Antonio, TX (Abstract Co-Author) Nothing to Disclose Geoffrey D. Clarke, PhD, San Antonio, TX (Abstract Co-Author) Nothing to Disclose Feng Gao, MD, San Antonio, TX (Presenter) Nothing to Disclose PURPOSE Non-Contrast Computed Tomography (NCCT) is the imaging modality of choice for acute stroke because of its easy access, efficiency, and cost effectiveness in excluding hemorrhage. However, according to earlier reports, approximately 39% cases show no early signs of infarction on NCCT. The purpose of this study is to retrospectively compare the initial NCCT with the follow up MRI results in patients with acute ischemic infarction and use CT density quantification to detect subtle infarctions that would have been missed by routine qualitative evaluation by radiologist. METHOD AND MATERIALS We retrospectively reviewed 16 patients (20 foci) who presented to the emergency department with acute stroke symptoms, obtained both NCCT and MRI scans. CT Hounsfield Units (HU) of both the infarctions, as defined by the MRI examination, and contralateral normal brain were quantified and compared. The sizes of the infarctions also had been recorded. RESULTS MRI confirmed 20 different foci (3.9mm – 46.3mm) of infarction within the 16 patients with suspected stroke. 15 out of the 20 infarctions were not visualized on NCCT. The CT density of the 15 occult infarctions (16.23 to 29.53 HU) showed an average of 4.34 HU lower than the contralateral normal area (20.86 to 33.21 HU). 12 out of the 15 infarctions had an average difference more than 5.27 HU while the other 3 differed less than 0.61 HU. CONCLUSION Earlier phantom studies indicates that 2 HU hypo-attenuation can be detected by using appropriate parameter settings. By comparing the CT numbers of the ischemic region with the contralateral normal brain, it has been found that 12 out of the 15 negative NCCT results (80%) could have been correctly reported as positive. Therefore, systematic quantification of the initial NCCT may aid in the CT diagnosis rate of acute ischemic stroke. The results of this study may serve as a base to establish a threshold for automatic detecting software development. The method of this study, which quantifies the infarction by measuring CT numbers, may also be used for further research to predict the prognosis of a stroke. CLINICAL RELEVANCE/APPLICATION (dealing with acute ischemic stroke by CT density quantification) “CT numbers have been used to quantify CT scans of acute ischemic stroke patients and the results showed significant improvement in diagnostic rate.” ER245-SDTHB4 Added Value of CT in Characterizing Lisfranc Injuries Station #4 Awards Student Travel Stipend Award Participants Brandon Roller, MD, PhD, Winston Salem, NC (Presenter) Consultant, Bone Solutions, Inc Pat W. Whitworth III, MD, Boston, MA (Abstract Co-Author) Nothing to Disclose Thomas Kelsey, Winston-Salem, NC (Abstract Co-Author) Nothing to Disclose Anna N. Miller, MD, Winston Salem, NC (Abstract Co-Author) Nothing to Disclose Scott D. Wuertzer, MD, MS, Winston-Salem, NC (Abstract Co-Author) Nothing to Disclose Leon Lenchik, MD, Winston-Salem, NC (Abstract Co-Author) Nothing to Disclose Maha Torabi, MD, Winston Salem, NC (Abstract Co-Author) Nothing to Disclose PURPOSE To determine the added value of computed tomography (CT) compared to conventional radiography (CR) for the diagnosis of fractures associated with Lisfranc injuries. METHOD AND MATERIALS A review of CT reports that specifically assessed the Lisfranc joint over the past 6 years was conducted. Only patients with foot radiographs prior to CT were included. Patients with diabetes or neuropathic arthropathy were excluded. CR and CT diagnoses were reviewed for the presence of the following fractures: medial, intermediate, and lateral cuneiforms; first, second, third, fourth, and fifth metatarsal bases; cuboid. The rate of fractures and malalignment on CR and CT were compared. The number of patients that had operative fixation of the Lisfranc injury was determined. RESULTS 148 patients were included (5 patients had bilateral CTs). There were 79 men (3 bilateral) and 69 women (2 bilateral); mean age, 49 years; age range, 19-92 years. 65/153 (42%) showed Lisfranc malalignment on CR. 82/153 (54%) showed Lisfranc malalignment on CT. 139/153 (91%) had fractures on CT. Compared to CT, CR diagnosed 17% (16/96) of medial cuneiform, 11% (5/47) of intermediate cuneiform, 7% (5/73) of lateral cuneiform, 45% (26/58) of first metatarsal base, 41% (44/107) of second metatarsal base, 31% (26/85) of third metatarsal base, 39% (31/79) of fourth metatarsal base, 44% (14/32) of fifth metatarsal base, and 34% (23/68) of cuboid fractures. CR missed identifying a fracture 90% (125/139) of the time. 57/153 patients had operative fixations. 9/57 (16%) of the patients who required surgery were CR negative but CT positive for Lisfranc malalignment. CONCLUSION Compared to conventional radiography, CT provides a more accurate characterization of fractures associated with Lisfranc injuries. CLINICAL RELEVANCE/APPLICATION CT provides an accurate characterization of fractures associated with Lisfranc injuries, which impacts patient management. MSCA52 Case-based Review of Abdomen (An Interactive Session) Thursday, Dec. 1 3:30PM - 5:00PM Room: S406A GI ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Julie H. Song, MD, Providence, RI (Director) Nothing to Disclose Sub-Events MSCA52A Imaging of Abdominal Trauma Participants Michael N. Patlas, MD, FRCPC, Hamilton, ON, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Discuss common mistakes in interpretation of cases of blunt and penetrating abdominal trauma. 2) Analyze factors leading to errors. 3) Discuss advantages of intraluminal contrast, delayed phase of imaging and multiplanar reconstructions for detection of traumatic injuries. ABSTRACT This case-based presentation will focus on uncommon abdominal blunt and penetrating traumatic injuries including bowel, pancreatic, biliary, adrenal, ureteric and vascular injuries. Misses and misinterpretations in the diagnosis of traumatic injuries on MDCT will be illustrated, based on lessons learned from Morbidity & Mortality Rounds. Optimised imaging protocols will be reviewed. Multimodality imaging evaluation of complications related to missed abdominal injuries will be discussed. MSCA52B Imaging of the Acute Abdomen Participants Douglas S. Katz, MD, Mineola, NY, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Demonstrate and review a series of challenging cases of CT of the acute abdomen and pelvis, in a case-based review session. 2) Review the differential diagnosis and potential pitfalls in the diagnosis of these entities. 3) Briefly review the further workup/management of these entities. ABSTRACT This presentation, in conjunction with several other speakers demonstrating case-based examples of various aspects of abdominal/pelvic imaging, will review a series of challenging CT cases of the acute abdomen and pelvis, with an emphasis on differential diagnosis and potential pitfalls. The literature of these entities - clinical and imaging - will be briefly reviewed, and the optimal management/further workup of these entities will be briefly discussed. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Douglas S. Katz, MD - 2013 Honored Educator Douglas S. Katz, MD - 2015 Honored Educator MSCA52C Abdominal Pain in Pregnancy Participants Ana P. Lourenco, MD, Providence, RI, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Describe a differential diagnosis for abdominal pain in pregnancy, as well as the best initial imaging study depending upon the leading differential diagnosis. 2) Recognize diagnostic findings across multiple modalities, including US, CT and MRI. 3) Explain some of the imaging pitfalls associated with each modality. ABSTRACT In this session, we will review the varied differential of abdominal pain in pregnancy, both gynecologic and non-gynecologic. Cases will be used to illustrate the imaging findings across multiple modalities, highlighting the importance of making the diagnosis at the first opportunity whenever possible. RC708 Imaging of the Extremities (An Interactive Session) Thursday, Dec. 1 4:30PM - 6:00PM Room: E350 MK ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Sub-Events RC708A Shoulder Participants Manickam Kumaravel, MD, FRCR, Houston, TX, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Recognize subtle injuries of the glenohumeral joint, acromioclavicular joint complex, coracoid, scapula and other less recognized injuries around the shoulder. 2) Understand the pathophysiology of shoulder injuries. 3) Learn to use cross-sectional imaging to better evaluate for clinically pertinent injuries. 4) Identify postoperative hardware in treated shoulder injuries. 5) Correlate the clinical significance of various types of injuries around the shoulder, so as to produce reports which will be relevant to the referring clinician. ABSTRACT RC708B Pelvis Participants Ken F. Linnau, MD, MS, Seattle, WA, ([email protected] ) (Presenter) Royalties, Cambridge University Press; Speaker, Siemens AG LEARNING OBJECTIVES 1) Identify pelvic ring disruptions and acetabular fractures. 2) Examine emergency department radiographs and CT scans of the pelvis to detect and describe PRD and acetabular fractures. 3) Differentiate PRD associated with a high risk of major pelvic hemorrhage from less severe injuries in order to aide in efficient clinical decision making and patient triage to angiography. 4) Describe acetabular fractures in a way that allows efficient communication with consultants and aid in clinical decision making for treatment. ABSTRACT Injuries to the pelvic ring (pelvic ring disruption, PRD) and acetabulum are relatively uncommon. Accordingly, such injuries are often treated at tertiary care centers by highly specialized providers. On the other hand, such injuries are often detected on trauma bay radiographs in the Emergency Department. PRD and acetabular fractures tend to be complex and associated with substantial morbidity and mortality. Pelvic radiographs are common initial studies for detection of PRD and acetabular fractures, but tend to be insufficient for full characterization of them. As a result CT scanning is often performed to aid in treatment decision making and operative planning. The purpose of this interactive presentation is to highlight specific clinical features and settings of such injuries which mandate expedited clinical decision making while the patient is still in the emergency room. Active Handout:Ken Floris Linnau http://abstract.rsna.org/uploads/2016/16000649/RC708B RSNA 2016 Linnau pelvic trauma RC708.pdf RC708C Ankle/Foot Participants Claire K. Sandstrom, MD, Seattle, WA, ([email protected] ) (Presenter) Royalties, Cambridge University Press; Speaker, Siemens AG LEARNING OBJECTIVES 1) Detect common clinically significant imaging abnormalities encountered in the foot and ankle in the emergency setting. 2) Detect subtle imaging abnormalities seen in the foot and ankle in the emergency setting. 3) Recommend appropriate follow up for various findings in the foot and ankle in the emergency setting. ABSTRACT RC708D Hand/Wrist Participants Jonathan A. Flug, MD, MBA, Denver, CO, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Detect imaging abnormalities commonly seen in the hand and wrist in the emergency setting. 2) Identify commonly encountered hand and wrist pathology in the emergency setting. 3) Recommend appropriate follow up for various findings in the hand and wrist in the emergency setting. ABSTRACT Radiologists routinely encounter imaging of the hand and wrist in both the general and subspecialty radiology settings. Appropriate recognition of various types of injuries and pathology are crucial for accurate diagnosis and optimal patient care. This lecture will review the various types of pathology the radiologist may encounter in the hand and wrist with an explanation of injury mechanism and appropriate follow up care. RC712 Acute Abdominal Vascular Diseases (An Interactive Session) Thursday, Dec. 1 4:30PM - 6:00PM Room: N229 GI VA ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants Dominik Fleischmann, MD, Palo Alto, CA, ([email protected]) (Moderator) Research support, Siemens AG; Handout:Dominik Fleischmann http://abstract.rsna.org/uploads/2016/13012007/Fleischmann_RSNA2016_RC712_Aortic_Branch_Dissections_HANDOUT.pdf Sub-Events RC712A Aortic Branch Dissections Participants Dominik Fleischmann, MD, Palo Alto, CA (Presenter) Research support, Siemens AG; LEARNING OBJECTIVES 1) Review the epidemiology of aortic side-branch dissections, which can occur as a complication of aortic dissection, or as isolated spontaneous dissections of the visceral or renal arteries. 2) Explain the pathophysiology of side branch malperfusion syndromes in aortic dissection. 3) Present the spectrum of imaging findings in spontaneous aortic branch dissections, including the differential diagnosis (vasculitis, connective tissue diseases, fibromuscular dysplasia, segmental arterial mediolysis). ABSTRACT Dissections of aortic side branches is a common complication of Type A and Type B acute aortic dissection which substantially increases mortality. It is important to understand the pathophysiology and the two principle mechanisms of side branch malferfusion in aortic dissection: flow obstruction can be due to (A) local abnormalities, such as occlusive dissection flaps, blind ending false lumen with true lumen occlusion ('windsock'), or frank thrombosis. Side-branch malperfusion may also occur due to (B) limited inflow: The classic situation is complete true lumen collapse in the upstream aorta, resulting in underperfusion of all downstream branches supplied by the true lumen. Wile local obstructions are most commonly treated by stent placement into the diseased side branch, inflow-lesions typically require surgical or endovascular repair of the upstream aorta. Spontaneous dissections of the celiac, mesenteric, or renal arteries are relatively rare events, and typically present with acute abdominal or flank pain. Dissections of side branch arteries can lead to ischemic complications or to frank rupture with intra- or retroperitoneal hemorrhage. Patients presenting with mesenteric or renal artery dissection require a thorough workup to identify genetic disorders (notably Ehlers Danlos IV), inflammatory conditions (vasculitis), and other entities such as fibromuscular dysplasia and segmental arterial mediolysis (SAM). Imaging findings range from non-obstructive lesions such as intramural hematoma, doublebarrel lumen, to partial or complete obstruction ('windsock'). Complications include rupture or ischemia. Spontaneous dissections may heal, or evolve into aortic branch aneurysms. RC712B Symptomatic Aneurysms Participants Phillip M. Young, MD, Rochester, MN, ([email protected]) (Presenter) Nothing to Disclose ABSTRACT Symptomatic aneurysms cover the spectrum of arterial aneurysms presenting with a) localized symptoms secondary to aneurysm expansion and possible rupture b) regional symptoms secondary to dissection and embolism and c) systemic cardiovascular dysfunction related to hypotension and organ dysfunction. Common clinical scenarios include aneurysm rupture – most commonly abdominal aortic, popliteal and abdominal visceral aneurysms as well as thoracoabdominal aortic dissection. Symptomatic aneurysms may also occur in patients with known arterial pathology including connective tissue disorders such as Marfan’s and Ehlers-Danlos syndrome and Takayasu aortitis/arteritis. Patients with suspected rupture of abdominal aortic or ileofemoropopliteal artery aneurysms may initially be evaluated by sonography. However, in all circumstances, CT angiography due to its robust implementation and high-resolution imaging of the vasculature and regional anatomy that allows for planning of endovascular and surgical intervention is the preferred technique. CT Angiographic protocols appropriate to the suspected anatomic location of the aneurysm that provide an adequate roadmap for endovascular or surgical intervention are employed. Extended coverage is particularly important in patients with suspected thoracoabdominal aortic dissection or aneurysms associated with peripheral embolism. Cardiac gating should be utilized in any patient with a suspected type A aortic dissection or rupture of an ascending aortic aneurysm. Aortic, cardiac and coronary artery imaging are integral to the evaluation and management of these patients. A particular subset of the “symptomatic aneurysm” is post-trauma aortic disruption, usually thoracic in which diagnosis of traumatic aneurysm is critical and the aneurysm is associated with additional sites of soft tissue and skeletal trauma. Guidelines for endovascular or surgical intervention or non invasive management with serial CT Angiographic imaging will be discussed. RC712C Mesenteric Ischemia Participants Iain D. Kirkpatrick, MD, Winnipeg, MB, ([email protected] ) (Presenter) Nothing to Disclose LEARNING OBJECTIVES 1) Discuss the various categories of mesenteric ischemia (arterial occlusive, embolic, venous thrombotic, and nonocclusive), and the pathophysiologic basis behind the imaging findings in each case. 2) Understand the basis behind modern CT protocols for mesenteric ischemia, particularly the biphasic examination with CT mesenteric angiography. 3) Demonstrate techniques to rapidly analyze a mesenteric CT angiographic dataset. 4) Review the CT signs of mesenteric ischemia and their sensitivity and specificity. 5) Evaluate the current literature on mesenteric ischemia and discuss optimal diagnostic criteria. ABSTRACT Acute mesenteric schema (AMI) is a life-threatening condition said to affect up to 1% of patients presenting with an acute abdomen, and it carries a mortality rate ranging between 59-93% in the published literature. Time to diagnosis and surgical treatment are the only factors which have been shown to improve mortality, and evidence shows that the clear test of choice for AMI is now biphasic CT. Water is preferably administered as a negative contrast agent, followed by CT mesenteric angiography and then a portal venous phase exam. Diagnostic accuracy is significantly improved by analysis of the CT angiogram for arterial stenoses or occlusions, evidence of emboli, or angiographic criteria of nonocclusive ischemia. It is the use of CT angiography in addition to routine portal phase imaging which has pushed the sensitivity and specificity of the test to >90% in recent published articles. Other nonangiographic CT findings that are relatively specific for AMI in the appropriate clinical setting include pneumatosis intestinalis, portal or mesenteric venous gas or thrombosis, and decreased bowel wall enhancement. Bowel wall thickening, mesenteric stranding, ascites, and mucosal hyperenhancement are more nonspecific findings which may also be seen. Nonocclusive schema may be the most difficult form to diagnose, and findings of shock abdomen can aid in identification. Knowledge of the patient's clinical history is critical not only for the selection of an appropriate study protocol but also for interpretation of the imaging findings in context. RC712D Gastrointestinal Bleeding Participants Jorge A. Soto, MD, Boston, MA (Presenter) Royalties, Reed Elsevier LEARNING OBJECTIVES 1) To review the appropriate implementation of CT angiography in the evaluation of patients presenting with acute lower intestinal bleeding. 2) To describe the technical details that are necessary for acquiring good quality CT angiography examinations. 3) Illustrate the characteristic CT angiographic findings of active or recent bleeding with specific examples of multiple etiologies. ABSTRACT Acute gastrointestinal bleeding is a serious condiition that may threaten a patient’s life depending on the severity and duration of the event. Precise identification of the location, source and cause of bleeding are the primary objectivse of the diagnostic evaluation. Implementation of colonoscopy in the emergency setting poses multiple challenges, especially the inability to adequately cleanse the colon and poor visualization owing to the presence of intraluminal blood clots. Scintigraphy with technetium 99m–labeled red blood cells is highly sensitive but also has some limitations, such as the inability to precisely localize the source of bleeding and determine its cause. Properly performed and interpreted CT angiography examinations offer logistical and diagnostic advantages in the detection of active hemorrhage. A three-phase examination (non-contrast, arterial and portal venous) is typically performed. Potential technical and interpretation pitfalls should be considered and will be explained. The information derived from CT angiography helps direct therapy and select the most appropriate hemostatic intervention (when necessary): endoscopic, angiographic, or surgical. Precise anatomic localization of the bleeding point also allows a targeted endovascular embolization. The high diagnostic performance of CT angiography makes this test a good alternative for the initial emergent evaluation of patients with acute lower intestinal bleeding. Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jorge A. Soto, MD - 2013 Honored Educator Jorge A. Soto, MD - 2014 Honored Educator Jorge A. Soto, MD - 2015 Honored Educator RC801 Imaging of Cardiothoracic Emergencies (An Interactive Session) Friday, Dec. 2 8:30AM - 10:00AM Room: E353C CH ER AMA PRA Category 1 Credits ™: 1.50 ARRT Category A+ Credits: 1.50 Participants LEARNING OBJECTIVES 1) To review imaging manifestations of common life-threatening complications of thoracic trauma. 2) To highlight common difficulties radiologists encounter when interpreting imaging studies in patients with thoracic trauma. 3) Overview current imaging strategies and key facts in Pulmonary Embolism imaging. 4) Provide an update on current issues and challenges in Pulmonary Embolism imaging. Sub-Events RC801A Thoracic Trauma Participants Santiago Martinez-Jimenez, MD, Kansas City, MO (Presenter) Author, Reed Elsevier; Author, Oxford University Press LEARNING OBJECTIVES 1) To review imaging manifestations of common life-threatening complications of thoracic trauma. 2) To highlight common difficulties radiologists encounter when interpreting imaging studies in patients with thoracic trauma. ABSTRACT Thoracic trauma is common, may imply life-threatening complications, and could be especially challenging for radiologists. Several reasons known to add complexity of interpretation of imaging studies include: lack of direct interaction with patients, unawareness of the mechanism of trauma, inherent poor diagnostic quality, satisfaction of search, and lack of knowledge of resultant pathophysiologic mechanisms. In this case based lecture several scenarios are presented with detailed analyses of imaging studies, mechanisms of trauma and pertinent involved pathophysiological principles. Some of the cases included are: acute traumatic aortic injury, diaphragmatic rupture, airway injury, aspiration, flail chest, and stenoclavicular dislocation. Active Handout:Santiago Martinez-Jimenez http://abstract.rsna.org/uploads/2016/16000670/RC801A Trauma RSNA 2016 003.pdf Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Santiago Martinez-Jimenez, MD - 2014 Honored Educator Santiago Martinez-Jimenez, MD - 2015 Honored Educator RC801B Pulmonary Embolism Participants Ioannis Vlahos, MRCP, FRCR, London, United Kingdom, ([email protected] ) (Presenter) Research Consultant, Siemens AG; Research Consultant, General Electric Company; LEARNING OBJECTIVES 1) Overview current imaging strategies and key facts in Pulmonary Embolism imaging. 2) Provide an update on current issues and challenges in Pulmonary Embolism imaging. ABSTRACT Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Ioannis Vlahos, MRCP, FRCR - 2015 Honored Educator RC801C Acute Aortic Syndrome Participants Jonathan H. Chung, MD, Chicago, IL (Presenter) Royalties, Reed Elsevier; Consultant, F. Hoffmann-La Roche Ltd; Consultant, Boehringer Ingelheim GmbH; Consultant, Veracyte, Inc Honored Educators Presenters or authors on this event have been recognized as RSNA Honored Educators for participating in multiple qualifying educational activities. Honored Educators are invested in furthering the profession of radiology by delivering high-quality educational content in their field of study. Learn how you can become an honored educator by visiting the website at: https://www.rsna.org/Honored-Educator-Award/ Jonathan H. Chung, MD - 2013 Honored Educator RC801D Acute Coronary Syndrome Participants Harold I. Litt, MD, PhD, Philadelphia, PA (Presenter) Research Grant, Siemens AG ; Research Grant, Heartflow, Inc; Travel Support, General Electric Company; LEARNING OBJECTIVES 1) Understand the demographics and clinical presentations of patients with suspected acute coronary syndromes and the pathways and guidelines used in their care. 2) Describe the evidence supporting the use of coronary CT angiography, SPECT myocardial perfusion imaging and stress echocardiography in low to intermediate risk chest pain patients. 3) Demonstrate typical findings at coronary CT angiography in patients with suspected acute coronary syndromes.