Triple rule-out and dedicated coronary artery CTA: comparison of coronary artery image quality

The aim of this study was to compare image quality on dedicated and triple rule-out coronary computed tomographic (CT) angiography (CTA) with respect to motion artifacts and the quality of coronary artery opacification.

Twenty dedicated coronary CT angiographic studies and 20 emergency department triple rule-out CT angiographic studies (ie, to rule out pulmonary embolism, aortic dissection, and acute coronary syndrome) performed on 64-slice CT scanner were selected. Two radiologists, blinded to type of CTA, scored coronary artery image quality. Up to 14 coronary artery segments were scored for motion artifact on a scale ranging from 1 (no motion artifact) to 4 (severe motion artifact). The radiologists also scored the quality of opacification (1 = good opacification, 2 = limited opacification, 3 = vessel not seen). The average of all segments and dedicated larger and smaller coronary artery segments was compared.

The average motion-artifact scores per vessel segment for dedicated and triple rule-out studies were 1.64 and 1.72, respectively (P = .6). For larger segments, the average motion-artifact score was 1.41 for dedicated CTA compared to 1.55 for triple rule-out CTA (P = .2). The average coronary artery opacification for dedicated studies was 1.05 for all segments and 1.03 for larger segments, compared to triple rule-out studies, which had scores of 1.09 (P = .5) for all segments and 1.06 (P = .5) for larger segments. No statistically significant differences in favor of dedicated CTA were identified.

The image quality of triple rule-out CTA is comparable to that of dedicated coronary CTA, showing no statistically significant difference in motion artifacts or opacification, and therefore may be an alternative and useful diagnostic study in a select group of emergency department patients.