CT artifacts: Causes and reduction techniques
... soft tissue boundaries may be obscured. For conventional filtered backprojection (FBP) images, the standard deviation in Hounsfield units (HU) due to Poisson noise [2] is proportional to 1/ slice thickness mAs . This relationship applies when comparing corresponding regions in two images acquired ...
... soft tissue boundaries may be obscured. For conventional filtered backprojection (FBP) images, the standard deviation in Hounsfield units (HU) due to Poisson noise [2] is proportional to 1/ slice thickness mAs . This relationship applies when comparing corresponding regions in two images acquired ...
RADIATION PROTECTION IN DIAGNOSTIC RADIOLOGY
... Intensifying screen structure (I) Supporting Base (mainly polyester material) – chemically neutral, resistant to X-ray exposure, flexible, ...
... Intensifying screen structure (I) Supporting Base (mainly polyester material) – chemically neutral, resistant to X-ray exposure, flexible, ...
IAEA - Human Health Campus
... EQUIPMENT-SPECIFIC CHECK SHEET FORMS FOR SECTIONS 3-5 The audit team members should use the Equipment-Specific Check sheet forms as internal tools to assist them in conducting the audit review. The assessments made using these check sheets will be summarized on the Audit Report Forms in Appendix II. ...
... EQUIPMENT-SPECIFIC CHECK SHEET FORMS FOR SECTIONS 3-5 The audit team members should use the Equipment-Specific Check sheet forms as internal tools to assist them in conducting the audit review. The assessments made using these check sheets will be summarized on the Audit Report Forms in Appendix II. ...
News Letter - Association of Medical Physicists of India
... analyzed 10 VMAT clinical cases shows average gamma of less than 1 (γ ≤ 1) at 3%-3mm gamma criteria. In addition to the tests discussed above EPID signal response with gantry angles (Gravity effect) has been evaluated and found maximum deviation of 0.41% & 0.15% for 6MV & 15MV respectively. Short te ...
... analyzed 10 VMAT clinical cases shows average gamma of less than 1 (γ ≤ 1) at 3%-3mm gamma criteria. In addition to the tests discussed above EPID signal response with gantry angles (Gravity effect) has been evaluated and found maximum deviation of 0.41% & 0.15% for 6MV & 15MV respectively. Short te ...
Physics Radiology In-Training Test Questions for Diagnostic
... A. Incorrect. Necrosis of the skin has dose threshold of >16 Gy. B. Incorrect. The dose threshold for main erythema is 6 Gy C. Incorrect. Desquamation occurs above 14 Gy. D. Correct. This effect has a lower dose threshold of 2 Gy. It may begin within hours after irradiation and peak at about 24 hour ...
... A. Incorrect. Necrosis of the skin has dose threshold of >16 Gy. B. Incorrect. The dose threshold for main erythema is 6 Gy C. Incorrect. Desquamation occurs above 14 Gy. D. Correct. This effect has a lower dose threshold of 2 Gy. It may begin within hours after irradiation and peak at about 24 hour ...
18. Optimization of protection in CT - RPOP
... practice in 1972 and revolutionized X Ray imaging by providing high quality images which reproduced transverse cross sections of the body. • Tissues are not superimposed on the image as they are in conventional projections • The CT provides improved low contrast resolution for better visualization o ...
... practice in 1972 and revolutionized X Ray imaging by providing high quality images which reproduced transverse cross sections of the body. • Tissues are not superimposed on the image as they are in conventional projections • The CT provides improved low contrast resolution for better visualization o ...
Flat detectors and their clinical applications
... larger dose range can be addressed without risking wrong exposures. This feature reduces the need for retakes substantially which is particularly handy if external dose sensing devices are not available, for example in case of free exposures. A word of caution, however, is necessary, as the large dy ...
... larger dose range can be addressed without risking wrong exposures. This feature reduces the need for retakes substantially which is particularly handy if external dose sensing devices are not available, for example in case of free exposures. A word of caution, however, is necessary, as the large dy ...
Imaging of Facet Joint Pathology - Washington Association of Nurse
... nuclear physicist, in 1963 described the mathematical basis for constructing a CT ...
... nuclear physicist, in 1963 described the mathematical basis for constructing a CT ...
Dose Reduction Strategies for SPECT/CT and PET/CT
... Diagnostic Reference Levels “Diagnostic reference levels (DRLs), which are a form of investigation levels, represent an important tool to optimize image quality and the radiation dose delivered to patients.” DRL’s help promote (not dictate) good practice for a more specific medical imaging task; an ...
... Diagnostic Reference Levels “Diagnostic reference levels (DRLs), which are a form of investigation levels, represent an important tool to optimize image quality and the radiation dose delivered to patients.” DRL’s help promote (not dictate) good practice for a more specific medical imaging task; an ...
New Technologies in 3D Conformal Radiation Therapy: Introduction
... tumor patients are suffering from a malignant localized tumor which has not yet disseminated, i.e., no metastatic disease has yet occurred; thus, these patients can be considered to be potentially curable. Nevertheless, about one-third of these patients (18% of all cancer patients) cannot be cured, ...
... tumor patients are suffering from a malignant localized tumor which has not yet disseminated, i.e., no metastatic disease has yet occurred; thus, these patients can be considered to be potentially curable. Nevertheless, about one-third of these patients (18% of all cancer patients) cannot be cured, ...
Managing Patient Dose in Computed Tomography (CT)
... INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION ...
... INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION ...
Diagnostic Medical Imaging Radiation Exposure and Risk of
... is associated with increased excess relative risk of developing radiation-induced malignancy during one’s lifetime. Given these data, risk of malignancy increases in a dose-dependent manner. Therefore, it is important to determine current patient exposures from diagnostic radiology studies and ident ...
... is associated with increased excess relative risk of developing radiation-induced malignancy during one’s lifetime. Given these data, risk of malignancy increases in a dose-dependent manner. Therefore, it is important to determine current patient exposures from diagnostic radiology studies and ident ...
Osteopenia – loss of bone mass (used more of a descriptive word)
... bones and flat bones except occiput, ribs, and portions of the pelvis. This type of growth never ends Initiated by proliferation of mesenchymal cells about a network of capillaries. Collagen fibers and ground substance join in forming a mesh-like matrix. The cells enlarge and become arranged in la ...
... bones and flat bones except occiput, ribs, and portions of the pelvis. This type of growth never ends Initiated by proliferation of mesenchymal cells about a network of capillaries. Collagen fibers and ground substance join in forming a mesh-like matrix. The cells enlarge and become arranged in la ...
Clinical applications of virtual, non
... Background: This study set out to evaluate the u lity of cerebrovascular virtual non-contrast (VNC) scans. Materials and Methods: Conven onal non-contrast (CNC) and dual-energy computed tomography angiography (DE-CTA) head scans were conducted on 100 subjects, of which 46 were normal, 15 had parench ...
... Background: This study set out to evaluate the u lity of cerebrovascular virtual non-contrast (VNC) scans. Materials and Methods: Conven onal non-contrast (CNC) and dual-energy computed tomography angiography (DE-CTA) head scans were conducted on 100 subjects, of which 46 were normal, 15 had parench ...
Standardized medical terminology for cardiac computed tomography
... The writing group focused on terms most relevant to cardiac CT. Not included within the scope of this document were more general terms related to vascular interpretation and analysis such as cross-sectional area or percent diameter stenosis. These were thought to be well understood or have been clea ...
... The writing group focused on terms most relevant to cardiac CT. Not included within the scope of this document were more general terms related to vascular interpretation and analysis such as cross-sectional area or percent diameter stenosis. These were thought to be well understood or have been clea ...
Effective dose range for dental cone beam computed tomography
... number of projections) and volume of the exposed field. Also, many devices allow a degree of versatility regarding the exposure, allowing the operator to select certain exposure parameters. It is clear that the range of devices and imaging protocols that are available will result in different absorbe ...
... number of projections) and volume of the exposed field. Also, many devices allow a degree of versatility regarding the exposure, allowing the operator to select certain exposure parameters. It is clear that the range of devices and imaging protocols that are available will result in different absorbe ...
DoseWatch - GE Healthcare
... Different combinations of imaging parameters can result in obtaining an answer to a specific clinical question. The goal of protocol optimization is to realize opportunities for dose conservation while maintaining image quality at levels acceptable for clinical interpretation.2 Another goal of proto ...
... Different combinations of imaging parameters can result in obtaining an answer to a specific clinical question. The goal of protocol optimization is to realize opportunities for dose conservation while maintaining image quality at levels acceptable for clinical interpretation.2 Another goal of proto ...
Specification And Acceptance Testing Of Computed
... The Computed Tomography (CT) Scanner Task Group was formed to provide a reference document of suggested procedures for acceptance testing of CT systems for clinical medical physicists. The AAPM first addressed performance testing of CT systems with the publication of AAPM Report No. 1, “Phantoms for ...
... The Computed Tomography (CT) Scanner Task Group was formed to provide a reference document of suggested procedures for acceptance testing of CT systems for clinical medical physicists. The AAPM first addressed performance testing of CT systems with the publication of AAPM Report No. 1, “Phantoms for ...
190047_190047 - espace@Curtin
... diagnostic imaging 1. Despite the benefits that these innovations have brought, concerns have been expressed about the escalating cost of unrestrained use of medical imaging. Introduction of helical (spiral) Computed Tomography (CT) scanning resulted in large increases in examinations performed and ...
... diagnostic imaging 1. Despite the benefits that these innovations have brought, concerns have been expressed about the escalating cost of unrestrained use of medical imaging. Introduction of helical (spiral) Computed Tomography (CT) scanning resulted in large increases in examinations performed and ...
mdct trauma protocol made efficient - SCBT-MR
... Body part Delay Recon Thickness Noise Index CTA of pelvis, ~ 23 sec 0.625 mm long bones bolus tracking ...
... Body part Delay Recon Thickness Noise Index CTA of pelvis, ~ 23 sec 0.625 mm long bones bolus tracking ...
ACR–AAPM Technical Standard for Management of the
... fluoroscopy safety standards. These physicians must also have documented evidence of at least 4 hours of didactic lectures and laboratory instruction in radiation physics, radiobiology, radiation safety, and radiation management ― including imaging of pediatric patients and pregnant patients [7,8] ― ...
... fluoroscopy safety standards. These physicians must also have documented evidence of at least 4 hours of didactic lectures and laboratory instruction in radiation physics, radiobiology, radiation safety, and radiation management ― including imaging of pediatric patients and pregnant patients [7,8] ― ...
Medical Scanners
... and was taken in 1895. The first medical use was just a few months later in 1896. X-rays are the most important and widespread of the modalities we will look at in this talk. The method of production is essentially ...
... and was taken in 1895. The first medical use was just a few months later in 1896. X-rays are the most important and widespread of the modalities we will look at in this talk. The method of production is essentially ...
Sample pages 1 PDF
... 2000). The increased performance allowed for the optimization of a variety of clinical protocols. Examination times for standard protocols could be significantly reduced; alternatively, scan ranges could be significantly extended. Furthermore, a given anatomic volume could be scanned within a given ...
... 2000). The increased performance allowed for the optimization of a variety of clinical protocols. Examination times for standard protocols could be significantly reduced; alternatively, scan ranges could be significantly extended. Furthermore, a given anatomic volume could be scanned within a given ...
Backscatter X-ray
Backscatter X-ray is an advanced X-ray imaging technology. Traditional X-ray machines detect hard and soft materials by the variation in transmission through the target. In contrast, backscatter X-ray detects the radiation that reflects from the target. It has potential applications where less-destructive examination is required, and can be used if only one side of the target is available for examination.The technology is one of two types of whole body imaging technologies that have been used to perform full-body scans of airline passengers to detect hidden weapons, tools, liquids, narcotics, currency, and other contraband. A competing technology is millimeter wave scanner. An airport security machine of this type is also referred to as ""body scanner"", ""whole body imager (WBI)"", ""security scanner"", and ""naked scanner"".