EVALUATION OF ELECTRON-BEAM CT CORONARY ANGIOGRAPHY IN HEALTHY-SUBJECTS

OBJECTIVE. This study evaluated the performance characteristics of ele ctrocardiographically triggered, contrast-enhanced electron beam CT (E BCT) in defining the coronary artery lumen in healthy subjects, SUBJEC TS AND METHODS. The coronary arteries of 11 healthy young men (mean ag e, 24 years old) were evaluated by contrast-enhanced EBCT. Measured pa rameters included degree of luminal enhancement, intravascular contras t-to-noise ratio, apparent luminal diameter, and length of continuousl y visualized lumen (100-H threshold for diameter and length measuremen ts). RESULTS. Aortic blood pool attenuation was 44 +/- 5 H (mean +/- S D) before and 278 +/- 35 H after IV injection of contrast material. Co ntrast-to-noise ratios ranged from a high of 10.0 +/- 2.6 in the proxi mal right coronary artery to a low of 3.2 +/- 2.7 in the distal left c ircumflex artery, decreasing from proximal to distal within each vesse l. Apparent luminal diameters were as follows: left main coronary arte ry, 4.5 +/- 0.6 mm; left anterior descending artery, 3.7 +/- 0.5 mm; l eft circumflex artery, 2.9 +/- 0.6 mm; and right coronary artery, 3.5 +/- 0.5 mm. The mean lengths of visualized lumina were as follows: lef t main coronary artery, 10 +/- 4 mm; left anterior descending artery, 65 +/- 26 mm; left circumflex artery, 45 +/- 20 mm; and right coronary artery, 58 +/- 24 mm. CONCLUSION. EBCT angiography can reveal the lum en of long segments of the major coronary arteries.