Application of high-pitch dual-source CT with prospective ECG gated double scan mode in postoperative follow-up of coronary artery bypass grafting / 解放军医学杂志

ABSTRACT

Objective To evaluate the application of high-pitch dual-source CT with prospective ECG gated double scan mode (Double Flash) in postoperative follow-up of coronary artery bypass grafting (CABG).Methods Sixty-one patients undergone CABG and received coronary CT angiography (CCTA) from Apr.2012 to Dec.2014 were enrolled in present study.The patients were randomly divided into two groups according to scanning modegroup A (Double Flash mode,30 cases) and group B (retrospective ECG gated spiral mode,31cases).Evaluation parameters included volumetric CT dose index (CTDIvol) and effective radiation dose (ED).All the coronary segments were evaluated with double blind method by two independent observers according to the image quality (IQ) on 4-point scale (1excellent to 4non-diagnostic).Results There were 139 coronary artery bypass grafts in 2 groups.Group A had 69 grafts,including 25 artery grafts and 44 venous grafts.Group B had 70 grafts,including 29 grafts and 41 venous grafts.No significant difference was found in IQ.between the two groups for all coronary segments (1.22 ± 0.57 vs.1.21 ± 0.61,P=0.975).ED (4.34 ± 1.88 vs.17.07 ± 2.13mSv,P＜0.001) and CTDIvol (5.70 ± 2.36 vs.40.95 ± 3.12mGy,P＜0.001) were significantly lower in group A than in group B.Conclusion Double Flash spiral protocol of dual-source CCTA can acquire good image quality with reduced radiation dose during assessment of CABG patency,and might have potential value in the follow-up of CABG patency.