Inter-rater reliability of electron beam computed tomography to detect coronary artery calcification

The electron beam computed tomography (EBCT) provides a safe, rapid, and noninvasive means to detect the presence and quantitate the deposition of calcium in the coronary arteries. To examine the inter-rater reliability of a coronary calcification screen using the EBCT, films from 50 subjects were scored by two technicians. The number, volume, and calcification scores were determined for each artery as well as a total score of coronary calcification. When scan results were interpreted qualitatively (all scores > 10 classified as positive) there was complete agreement between raters in identifying the 22 cases with a positive total scan, and only one instance of discrepancy in identifying positive results for specific arteries. When scores for the 32 cases with non-zero calcium scores were analyzed quantitatively, inter-rater correlation coefficients of 0.98 or higher were observed for the total scan scores and for scores in three of four arteries. In only four cases did the total scan scores from the two raters differ by more than 10%. Therefore, evidence suggests that EBCT films can be reliably scored, enhancing their potential usefulness in the early detection of coronary atherosclerosis.