Coronary Artery Disease: Cheng V

Raff GL, Abidov A, Achenbach S, Berman DS, Boxt LM, Budoff MJ, Cheng V, DeFrance T, Hellinger JC, Karlsberg RP, Anonymous00022. · Society of Cardiovascular Computed Tomography, 2400 N Street NW, Washington, DC 20037, USA. · J Cardiovasc Comput Tomogr. · Pubmed #19272853 No free full text.

This publication has no abstract.

Gutstein A, Dey D, Cheng V, Wolak A, Gransar H, Suzuki Y, Friedman J, Thomson LE, Hayes S, Pimentel R, Paz W, Slomka P, Le Meunier L, Germano G, Berman DS. · Department of Imaging, Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, USA. · J Cardiovasc Comput Tomogr. · Pubmed #19083968 No free full text.

Abstract: BACKGROUND: Strategies to reduce the radiation dose of coronary computed tomography angiography (CCTA), while maintaining diagnostic image quality, are imperative for cardiac CT. OBJECTIVE: We aimed to reduce radiation dose during helical dual-source CCTA by combining lower tube voltage, shortest possible full tube current (FTC) window, and minimal tube current outside the FTC window, and to develop a patient-based algorithm for applying these dose-reduction components. METHODS: We compared FTC at 70% of the cardiac cycle (FTC70) to a 45% to 75% window (FTC45-75) using both 100 and 120 kVp (N=118). FTC70 was used in patients with heart rates <70 beats/min, no arrhythmia, age <65 years; 100 kVp was used in patients with body mass index (BMI) <30, a low coronary calcium score (CCS), and no stents. Objective and subjective image quality were assessed. RESULTS: Compared with FTC45-75 at 120 kVp, radiation dose was reduced by 66% for FTC70 at 100 kVp (mean radiation dose: 4.4 +/- 0.9 mSv) and by 43% for FTC70 at 120 kVp. 99% of 780 segments in the FTC70 group were of diagnostic quality. Noise, signal-to-noise ratio, and contrast-to-noise ratio were comparable between FTC70 and FTC45-75 for both 100 and 120 kVp. BMI, CCS and maximal heart rate variation were predictors of image quality. Tube voltage, FTC window width, scan length, and average heart rate were predictors of radiation dose. CONCLUSIONS: A successful patient-based algorithm for radiation dose reduction during helical CCTA using DSCT has been developed and validated in clinical practice.

Dey D, Lee CJ, Ohba M, Gutstein A, Slomka PJ, Cheng V, Suzuki Y, Suzuki S, Wolak A, Le Meunier L, Thomson LE, Cohen I, Friedman JD, Germano G, Berman DS. · Department of Imaging, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Taper Building, A1258, Los Angeles, CA 90048, USA; David-Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA, USA. · J Cardiovasc Comput Tomogr. · Pubmed #19083930 No free full text.

Abstract: INTRODUCTION: We aimed to characterize artifacts observed in a routine clinical coronary CT angiography (CCTA) performed by a dual-source CT (DSCT) scanner (Definition; Siemens Medical Solutions). METHODS: Studies of 167 consecutive patients referred for CCTA, performed after beta-blockade (if not contraindicated), were prospectively analyzed for artifacts with a predefined visual approach. American Heart Association coronary segments (n = 2589) were assessed in 40%-80% R-R interval phases by 2 experts for stenosis, plaque presence or composition, and presence or type of artifacts. Each segment was considered evaluable when image quality was diagnostic in at least one cardiac phase. Artifacts included motion (cardiac, respiratory, patient), phase misregistration because of varying heart beats, calcified plaque blooming or beam hardening, metal beam hardening, large patient size, and contrast timing error. RESULTS: Maximum HR (HR) during CCTA ranged from 45 to 120 beats/min (66.4 +/- 14.8 beats/min). Artifacts of some type were observed in 69 (41.3%) of 167 studies. Calcified plaque was the most common source of artifacts (14.4%), followed by misregistration (13.8%). Only 25 (1%) of 2589 coronary segments, in 6 (4%) of 167 patients were unevaluable, primarily because of calcified plaque blooming (coronary calcium score [CCS], 1112 +/- 1255]. Artifacts were associated with CCS (P = 0.002), change in HR (P = 0.01), age (P = 0.03), and body mass index (P = 0.048). The optimal phase for evaluation of all coronary arteries was 70% (mid-diastole), with a shift toward the systolic phases for HR > 70 beats/min. CONCLUSION: CCTA artifacts with DSCT were related primarily to calcified plaque and cardiac phase misregistration. When correctly recognized, the artifacts did not have a serious effect on the final interpretation.

Gutstein A, Wolak A, Lee C, Dey D, Ohba M, Suzuki Y, Cheng V, Gransar H, Suzuki S, Friedman J, Thomson LE, Hayes S, Pimentel R, Paz W, Slomka P, Berman DS. · Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. · J Cardiovasc Comput Tomogr. · Pubmed #19083926 No free full text.

Abstract: BACKGROUND: Prospectively gated coronary computed tomographic angiography (CCTA) with dual-source CT allows substantial reduction of radiation exposure but requires prospective single-phase selection and assessment of likelihood of adequate image quality. OBJECTIVE: We developed and tested the model for predicting success of prospectively gated CCTA. METHODS: Retrospectively gated CCTA was acquired with dual-source CT in 162 patients. Two cardiologists assessed by consensus whether diagnostic quality images could have been obtained in a single predefined phase, 70% of R-R interval (70P), thereby identifying patients in whom a prospectively gated scan at 70P would have been successful. Logistic regression models were built with and without a coronary calcium scan. The obtained criteria were applied on 42 additional patients. RESULTS: By logistic regression, heart rate before CCTA of >or=70 beats/min, maximal heart rate variation before CCTA of >or=10 beats/min, coronary calcium score >or= 400 U, and body mass index (in kg/m(2)) >or= 30 were independent predictors of unsuccessful prospectively gated CCTA using 70P. Excluding coronary calcium score from the model, these same variables in addition to age > 65 years were found to be predictors of unsuccessful prospectively gated CCTA. Applying this model to 42 additional patients, using prospective gating, only 5 segments in 4 patients were nondiagnostic. Mean radiation dose for prospectively gated CCTA was 2.2 +/- 0.8 mSv. CONCLUSION: Prospectively gated CCTA with dual-source CT can be successfully implemented with consideration of prescan heart rate, heart rate variability, body mass index, and coronary calcium score.