Reliability of electron beam computed tomography to detect coronary artery calcification

Electron beam computed tomography (CT) provides a safe, rapid, and noninvasive means to detect the presence and quantitate the deposition of calcium in the coronary arteries. To examine the reproducibility of a coronary calcification screen using electron beam CT, 50 subjects underwent two studies, averaging 12 minutes between studies. The number, volume, and calcification scores were determined for each artery as well as a total score of coronary calcification. Thirty-four of the 50 subjects had evidence of coronary calcification. The reliability score for total coronary artery calcification was 0.99. The reliability score for the total number of lesions and total volume was at or above 0.98. There were 8 cases in which a negative calcium score on retest was positive or where a positive calcium score on retest was negative. In both instances, the amount of calcium detected was very small. Therefore, evidence suggests that electron beam CT is reliable in the detection of coronary artery calcification and may be a useful tool for the early detection of coronary atherosclerosis before flow impairment.