Helical and single-slice conventional CT versus electron beam CT for the quantification of coronary artery calcification

OBJECTIVE. We compared electron beam CT with conventional CT to determine t he best method for the assessment of the coronary calcium score. We used co nventional CT to examine symptomatic and asymptomatic patients suspected of having coronary artery disease. SUBJECTS AND METHODS. One hundred sixty male patients underwent electron be am CT and helical CT with a pitch of 1 (n = 30) and 2 (n = 30) and using a single-slice mode with (n = 50) and without (n = 50) prospective ECG trigge ring. In another 50 patients, we determined reproducibility for repeated sc anning using electron beam CT. For all images, we derived the calcium score according to the Agatston method. We performed regression analysis and det ermined mean variability. Mean variability was calculated as the ratio of t he absolute difference to the mean of the corresponding calcium scores. RESULTS. The correlation coefficients for electron beam CT and all conventi onal CT modes were very high (range, 0.93-0.98). The mean variability was h ighest in the helical mode with a pitch of 2 (61.4%) and lowest for the sin gle-slice mode with prospective ECG triggering (25.4%). For repeated electr on beam CT, the correlation coefficient and mean variability were 0.99 and 22.1%, respectively. CONCLUSION. ECG-triggered single-slice conventional CT had the best agreeme nt with electron beam CT calcium scores.