Small lesions in the heart identified at electron beam CT: calcification or noise?

Abstract

PURPOSE: To identify a minimum definition of coronary artery calcification (CAC) at electron beam computed tomography (CT) that would give repeatable results and be accurate as a marker for coronary artery disease. MATERIALS AND METHODS: Hyperattenuating (> 130 HU) foci 0.69-3.09 mm2 in area were evaluated for 256 subjects who underwent two sequential electron beam CT examinations to determine the percentage of hyperattenuating foci seen on a first examination that were seen again on a second examination. Accuracies of varying minimum definitions of CAC were determined in 160 subjects who underwent electron beam CT and coronary arteriography. RESULTS: Hyperattenuating foci more than 2 mm2 in area were seen again at a second examination in more than 50% of cases (P < .0001). At this minimum definition of CAC, the sensitivity and specificity for identifying any angiographically defined coronary artery disease were 82% and 85%, respectively. CONCLUSION: The 2-mm2-area definition of CAC was reliable and provided an accurate indication of coronary artery disease.