The importance of angled right anterior oblique views in improving visualization of the coronary arteries. Part II: Craniocaudal view.

The craniocaudal right anterior oblique view (RAO) of the left coronary artery was employed for 100 angiograms. Visualization of the proximal and left distal circumflex, first and second marginal, and proximal left anterior descending artery (LAD) and its branches was compared with that on the non-angled RAO projection. Diagnostic accuracy was increased with the caudal RAO view in 88% of proximal circumflex segments, 69% of distal circumflex segments, 52% of first marginal segments, 33% of second marginal segments, and 33% of proximal LAD systems. Of 68 lesions identified, 15 (22%) were seen only on the caudal RAO view. The authors feel that this projection is a valuable and necessary addition to routine views of the left coronary artery, and that optimum evaluation is achieved by routine use of a combination of caudal, non-angled, and cranial RAO views.