Coronary CT angiography with 64-MDCT: Assessment of vessel visibility

OBJECTIVE. The objective of our study was to evaluate the image quality of 64-MDCT coronary angiography. SUBJECTS AND METHODS. Fifty consecutive CT coronary angiograms obtained on a scanner were independently reviewed by two reviewers. Segments were scored as no motion (score of 1), minimal motion (2), moderate motion (3), respiratory motion (4), vessel blurting (5). Opacification was graded as good (score of 1) or limited (2). Segments < 2 were graded as well seen; or as poorly seen or not seen. The scores for motion artifact, opacification, and visibility were combined for overall vessel assessment. Segments with a motion of 1 or 2 that had good opacification and were well seen were judged to be assessable. RESULTS. A total of 714 segments were analyzed in 50 patients. Seven hundred segments assessed in all patients (segments 1-3, 11-20, 4, or 27), and a ramus intermedius segment evaluated in 14 patients. Combining the scores for both reviewers, the average motion score I for 619 segments (86.7%), the average motion score for all segments in an individual patient 1.14 (range, 1-3.35), and the average opacification score for all segments in a patient was (range, 1-1.38). A total of 374 segments were less than 2 min in diameter. Combining the for both reviewers, an average of 36 segments (5.0% of 714) could not be identified by the 319.5 segments (85.4%) were well seen, and 18.5 segments (4.9%) were poorly seen. an average of 637 segments (89.2%) were judged assessable by the reviewers. On a per-patient basis, 10 or more vessel segments werejudged assessable in 47 patients (94%). CONCLUSION. On 64-MDCT, 89% of coronary artery segments are assessable. Ten or vessel segments are assessable in 94% of patients.