OBJECTIVETo identify reasons for poor image quality and nonassessability of coronary artery segments, and compare results between early and late diastolic triggering on coronary electron beam angiography (EBA).

METHODSOne hundred patients referred for EBA were studied. Contrast-enhanced transaxial coronary images were acquired using electrocardiographic triggering and reconstructed three-dimensionally using volume rendering techniques. The image quality of coronary segments and image artifacts were analyzed statistically.

RESULTSVolume rendering was failed in 7 patients (7%) due to cardiac and breathing motions. Image quality was the best with the left main (LM), and worst with the left circumflex (LCX) coronary artery (P < 0.001). The image quality decreased systematically from proximal to distal within each coronary artery (P < 0.001). Forty percent R-R interval triggering on electrocardiography was better than 80% for image quality. The nonassessable segments occurred in 3% of LM, 2%, 8%, and 5% of proximal, 24%, 22%, and 12% of mid, 64%, 45%, and 20% of distal segments of the left anterior descending (LAD), LCX, and right coronary artery (RCA), respectively (P < 0.05).

CONCLUSIONSThe major limitations of coronary EBA are in suboptimal spatial resolution and image artifacts. The image quality could be improved by using optimal electrocardiographic triggering.