Comparison of different scan protocols in dual-source CT coronary artery bypass graft angiography / 实用放射学杂志

ABSTRACT

Objective To compare the image quality and radiation dose of prospective electrocardiogram(ECG)-triggered high-pitch spiral scan,prospectively triggered sequential scan and retrospectively triggered spiral scanning mode by dual-source CT in the follow-up of coronary artery bypass graft(CABG).Methods Totally 90 patients with stable heart rate(≤65 beats per minute)after bypass surgery were randomized to undergo prospective high-pitch spiral scan in group A (n=30),prospective sequential scan in group B (n=30),and retrospective spiral scan in group C (n=30).The patency and image quality of the grafts were blindly evalua-ted by two independent readers.Moreover,radiation dose of the three modes were evaluated.Results Scanning time of group A was significantly shorter than that of group B and group C (P<0.05).The average image quality score had no significant difference among three groups(H=0.449,P=0.799).The effective radiation dose of group A,group B and group C were (2.64±1.21)mSv, (6.48±2.58)mSv and(18.95±7.16)mSv,which was significantly lower in group A(H=101.21,P=0.00).Conclusion In pa-tients with a stable HR of 65 beats per minute or less,high-pitch spiral CT scan provides similar image quality at lower radiation dose compared with sequential scan and retrospective spiral scan,which can be widely used as a non-invasive effective tool for the post-operative follow-up of CABG.