Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Value of "large" FOV calcium score as as screening method for detection of extracardiac incidental findings Poster No.: C-0997 Congress: ECR 2012 Type: Scientific Paper Authors: A. S. Ibrahim, W. Tantawy; Cairo/EG Keywords: Cardiac, CT-Angiography, CAD, Obstruction / Occlusion DOI: 10.1594/ecr2012/C-0997 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myESR.org Page 1 of 16 Purpose The purpose of this study was to emphasize the value of calcium scoring (Ca score) using a large field of view ("large FOV") as a screening method for detection of extracardiac incidental findings Methods and Materials Between July 2010 and December 2011, 382 consecutive patients candidate for coronary MDCT exam were scanned starting by a calcium score exam - using a "large FOV" - followed by a routine "small FOV" coronary CT angiography examination (CCTA). Patientswere excluded if they declined to enter this study (n=5) ordid not have an accessible large intravenous line (n=2). The remaining patients gave their informed consent and a total of 375 patients, 203 men and 172 women, ranging between 40-80 years (mean, 60 years), were included in study. Image Acquisition All MDCTA examinations were performed with a MDCT scanner (Toshiba® Aquilion 64 CT Scanner) at Misrscan center located in east Cairo, Egypt. As a preparatory phase non-contrast calcium score was preliminary done using a "large FOV" of 32-50 cm, other CT technical parameters included mA: 250-300; kV: 120; and section thickness, 3mm x 4 detectors. Then arterial enhancementwas provided by IV administration, in an antecubital vein throughan 18- to 20-gauge IV catheter, of 65-85 mL of nonionic iodinatedcontrast material (Ultravist 370 [iopromide], Bayer HealthCare [formerly Schering] at an injectionrate of 5-5.5mL/s with a power injector (double syringe pump), sure start 160, "small FOV": 18-24 cm (Fig 1,2); mA: 300-400; kV: 120; and section thickness, 0.5 mm x 64 detectors. CT Reconstruction ® All images werereviewed on Vitrea Workstation in axial, coronal and sagittal planes as well as MIP, MPR, 3D volume rendering and curved MPR after evaluation of calcium score. Image Analysis/Interpretation Page 2 of 16 Two experienced radiologists, in a blind protocol, independently reviewedall cases. The reviewers surveyedeach calcium score exam using axial source images for evaluation of extracardiac findings. No specific window level settingswere prescribed for image analysis. Instead, each reviewer modifiedthese settings to better depict the extracardiac incidental findings. Usually all images were reviewed in the axial plane using all of the following settings: mediastinal windows (width=400, level=40), lung windows (width=1500, level= 500), vascular (width=700, level=200) and bone windows (width=2000, level=350) and in general, the window level settingswere quite large, progressing to very wide settings in the casesof dense calcifications (usually around W2093:L792). Results were classified into four groups: 1) Emergent findings where therapy is often needed 2) Intermediate findings where timely workup is often needed 3) Mild findings where later follow-up is often needed 4) Incidental lesions where follow-up is often not needed (Figure 4). Afterwards, the two radiologists reviewed the findings together and reached a consensus about the findings. Images for this section: Page 3 of 16 Fig. 1: MDCT Ca score using a "small FOV" Page 4 of 16 Fig. 2: MDCT Ca score using "large FOV". Dose calculation and analysis of our cases, on a 64 MDCT scanner, showed an increase of +/- 1.2-1.9 mSv in dose, comparing ca score with a "large FOV" technique dose versus that of a "small FOV" technique Page 5 of 16 Results 375 patients, 203 men and 172 women, 40-80 years old (mean, 60 years), were included in this study; incidental extracardiac findings were found in 62.4% of scanned patients (figure 2,3,4). Usage of "large FOV" technique during Ca score acquisition in all our cases permitted detection of a higher percentage of incidental extracardiac findings. Among whole incidental extracardiac findings, "significant" extracardiac abnormalities (emergent and intermediate findings) were detected in 93 out of 375 cases (24.8%), 42 cases (11.2%) out of these 93 cases were detected by using "small FOV" technique, so 51 out of remaining 93 cases (13.6%) would have been missed if only using a "small FOV" technique (Table 1,2,3). Dose calculation and analysis of our cases, on a 64 MDCT scanner, showed an increase of +/- 1.2-1.9 mSv in dose, comparing ca score with a "large FOV" technique dose versus that of a "small FOV" technique. Images for this section: Page 6 of 16 Fig. 3: MDCT angiography for coronary assessment using the standard "small FOV" revealing a left sided bronchogenic carcinoma. Page 7 of 16 Fig. 4: MDCT: "Large FOV" Ca score for Fig 3 patient revealing suspicious pulmonary deposit, that would only have been detected with the "large FOV" technique. Page 8 of 16 Fig. 5: MDCT: "Large FOV" Ca score for another patient revealing benign pulmonary deposit, that would only have been detected with the "large FOV" technique. Page 9 of 16 Page 10 of 16 Table 1: Distribution of emergent and intermediate significant findings. Extra cardiac findings detected using "large FOV" compared to "small FOV" technique Table 2: Distribution of all extracardiac incidental abnormalities Table 3: Calculation of additional significant extracardiac abnormalities using "Large FOV" compared to "small FOV". Table 4: Distribution of all extracardiac incidental abnormalities according to their anatomical location: extracardiac upper mediastanal findings - from lung apex to level of carina, and extracardiac peripheral findings representing findings outside the confines of the pericardium. Page 11 of 16 Fig. 6: Distribution of extra cardiac findings detected via "large FOV" Ca score among 375 consecutive patients candidate for coronary MDCT between June 2010 and December 2011. Results were classified into four groups: 1) Emergent findings where therapy is often needed 2) Intermediate findings where timely workup is often needed 3) Mild findings where later follow-up is often needed 4) Incidental lesions where followup is often not needed. Among whole incidental extracardiac findings, "significant" extracardiac abnormalities (emergent and intermediate findings) were detected in 24.8%, among which 13.6% would have been missed if only using a "small FOV" technique. Page 12 of 16 Conclusion Using a "large FOV"; Incidental extracardiac abnormalities were detected in 62.4% of the scanned patients. Among those incidental extracardiac findings, "significant" extracardiac abnormalities (emergent and intermediate findings) were detected in 24.8%, among which 13.6% would have been missed if only using a "small FOV" technique. For ca scoring with "large FOV" technique; only a small increase in patient dose was needed (1.2 -1.9 mSv). We would specially recommend with new MDCT including dual, 256 and 320 detectors CT machines -using a sub mSv dose- routine acquisition of "large FOV" for detection of more extra-cardiac findings including serious significant findings as lung cancer or metastatic nodules at a very small expense in dose. We confirmed that the frequency of incidental findings is influenced by the scanning range. Larger scanning ranges containing more anatomic structures would reveal a greater number of incidental findings and several serious diagnoses would be missed with the limited viewing approach. 6.6% of our cases were extracardiac upper mediastinal findings while 14.9% of our cases were extracardiac peripheral findings Our results showed that before performing a coronary MSCT angiography with contrast, carrying out a Ca score with a "large FOV" is important for detection of extracardiac incidental findings in addition to usage of ca scorring as a risk factor for assessment of cardiac disease and anticipation of the degree of difficulty in the evaluation of the coronaries especially in cases where high Ca burden was detected in a single major artery. Using "large FOV", only a subtle increase in dose was noted in our study estimated at +/- 1.2-1.9 mSv. Radiologists should aim at analyzing the non-cardiac findings as meticulously as possible to ensure that important findings that might be responsible for a patient's symptoms are not missed and unnecessary follow-up examinations are avoided. A patient with absolutely normal coronary arteries could have a potentially life-threatening finding in the thorax accounting for chest pain, such as acute pulmonary embolism, acute aortic syndrome, or a relatively benign finding such as a large hiatal hernia. Thus, interpreters of cardiac CTA images should have adequate training and skill in differentiation between benign and potentially clinically significant lesions so as not to cause undue cost or patient anxiety and reducing additional work-up. References Page 13 of 16 [1] Colletti PM.: Incidental findings on cardiac imaging. Am J Roentgenol, 2008; 191:882-884. [2] Lee CI, Tsai EB, Sigal BM, et al: Rubin GD. Incidental extracardiac findings at coronary CT: clinical and economic impact. AJR Am J Roentgenol. 2010 Jun;194(6):1531-8. [3]Turkvatan A., Akdur O P., Akgul A. et al: Prevalence of incidental extra-cardiac findings on multidetector computed tomographic coronary angiography.Turkiye klinikleri J med sci., 2009; 29(1):169-75. [4] Mueller J., Jeudy J., Poston R. et al: Cardiac CT angiography after coronary bypass surgery: prevalence of incidental findings Am J Roentgenol, 2007; 189:414-419. [5] Kim TJ , Han DH , Jin KN , Won Lee K . Lung cancer detected at cardiac CT: prevalence, clinicoradiologic features, and importance of full-field-of-view images . Radiology 2010 ; 255 ( 2 ): 369 - 376. [6] Elizabeth R. Brown, Richard A. Kronmal, David A. Bluemke et al: Coronary Calcium Coverage Score: Determination, Correlates, and Predictive Accuracy in the Multi-Ethnic Study of Atherosclerosis. Radiology June 2008 247:669-675; [7] Sosnouski D., Bonsall RP., Mayer FB. Et al:Extra-cardiac findings at cardiac CT.A Practical approach J thoracic imaging, 2007; 22 (1):77-85. [8] Sun Z.:Multislice CT angiography in cardiac imaging: prospective ECG-gating or retrospective ECG-gating? Biomed imaging Interv J, 2010; 6(1):e4. [9] Sun Z. and Ng KH:Multislice CT angiography in cardiac imaging. Part III: radiation risk and dose reduction Singapore Med J, 2010; 51(5): 374. [10] Lehman SJ , Abbara S , Cury RC , et al . Significance of cardiac computed tomography incidental findings in acute chest pain Am JMed 2009 ; 122 ( 6 ): 543 - 549. Page 14 of 16 [11] Dewey M., Schnapauff D., Teige F et al: Non-cardiac findings on coronary computed tomography and magnetic resonance imaging. Eur Radiology, 2007; 17: 2038-2043. [12] Venkatesh Vikram, You John J., Landry David J. et al: Extra-cardiac findings in cardiac computed tomographic angiography in patients at low to intermediate risk for coronary artery disease. Canadian association of radiologists journal, 2010; 61: 286-290. [13] Kim JW., Kang EY. and Yong HS. et al: Incidental extra-cardiac findings at cardiac CT angiography: comparison of prevalence and clinical significance between precontrast low-dose whole thoracic scan and postcontrast retrospective ECG-gated cardiac scan Int J Cardiovasc imaging, 2009; 25:75-81. [14] Sundaram Baskaran, Patel Smita, Agarwal Prachi et al: Anatomy and terminology for the interpretation and reporting of cardiac MDCT: Part 2, CT angiography, cardiac function assessment, noncoronary and extra-cardiac findings AJR, 2009; 192:584-598. [15] Godoy MC, Naidich DP. Subsolid pulmonary nodules and the spectrum of peripheral adenocarcinomas of the lung: recommended interim guidelines for assessment and management. Radiology. 2009 Dec;253(3):606-22. [16] Fantauzzi John, MacArthur Alex, Lu Minh et al: Quantitative Assessment of Percentage of Lung Parenchyma Visualized on Cardiac Computed Tomographic Angiography. J computed assist tomography, 2010; 34(3): 385-387. [17] Johnson Kevin M.:Extra-cardiac findings on cardiac computed tomography.A radiologist's perspective. Journal of the american college of cardiology, 2010; 55(15): 1566-8. [18] Kirsch J., Araoz PA., Steinberg FB. et al:Prevalence and significance of incidental extra-cardiac findings at 64-multidetector coronary CTA. J thoracic imaging, 2007; 22(4):330-334. [19] Rumberger John A.: Noncardiac abnormalities in diagnostic cardiac computed tomography. Within normal limits or we never looked Journal of the American College of Cardiology, 2006; 48(2): 407-8. [20] White CS. The pros and cons of searching for extracardiac findings at cardiac CT: use of a restricted field of view is acceptable. Radiology. 2011 Nov;261(2):338-41. Page 15 of 16 Personal Information Ahmed S. Ibrahim Radiodiagnosis Department, Ain Shams University, Cairo, Egypt [email protected] Page 16 of 16