Evaluation of electron beam CT coronary angiography in healthy subjects

OBJECTIVE. This study evaluated the performance characteristics of electrocardiographically triggered, contrast-enhanced electron beam CT (EBCT) in defining the coronary artery lumen in healthy subjects, SUBJECTS AND METHODS. The coronary arteries of 11 healthy young men (mean age, 24 years old) were evaluated by contrast-enhanced EBCT. Measured parameters included degree of luminal enhancement, intravascular contrast-to-noise ratio, apparent luminal diameter, and length of continuously visualized lumen (100-H threshold for diameter and length measurements). RESULTS. Aortic blood pool attenuation was 44 +/- 5 H (mean +/- SD) before and 278 +/- 35 H after IV injection of contrast material. Contrast-to-noise ratios ranged from a high of 10.0 +/- 2.6 in the proximal right coronary artery to a low of 3.2 +/- 2.7 in the distal left circumflex artery, decreasing from proximal to distal within each vessel. Apparent luminal diameters were as follows: left main coronary artery, 4.5 +/- 0.6 mm; left anterior descending artery, 3.7 +/- 0.5 mm; left 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: left 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 lumen of long segments of the major coronary arteries.