Preliminary study of “double low”Dual-source coronary CT angiography in coronary artery bypass grafts

XU Lei; WANG Hui; ZHANG Nan; YANG Lin; FAN Zhan-ming; LV Biao; YU Wei

Abstract：Objective To evaluate the feasibility and effectiveness of “double low”coronary CT angiography (CCTA) in patients with coronary artery bypass grafts (CABG) .Methods A total of 38 consecutive patients underwent CABG follow up with CCTA were prospectively enrolled .Prospectively ,ECG‐triggered sequential imaging with low tube voltage and it‐erative reconstruction integrating with low concentration Iodixanol 270 (270 mgI/ml) were used in CCTA study .Of the enrolled patients ,20 cases also underwent invasive coronary angiography (CAG) .Subjective assessment of image quality and presence of significant stenosis (≥50% ) and occlusion of coronary grafts was performed .The sensitivity ,specificity , positive predictive value (PPV) ,and negative predictive value (NPV) were calculated using CAG as the reference stand‐ard .Results A total of 76 CABG vessels were analyzed .In total 387 segments of coronary grafts evaluated ,385(99 .5% ) segments were diagnostically evaluable .The sensitivity ,specificity ,PPV ,and NPV of CCTA for diagnosing the signifi‐cant stenosis of coronary grafts were 100% (4/4) ,97 .6% (40/41) ,80 .0% (4/5) ,and 100% (40/40) .Nine occluded coro‐nary grafts were accurately diagnosied with CCTA .Conclusion “Double low” CCTA is feasible in patients with CABG . This protocol can reduce the radiation dose and iodine load while maintaining diagnostic image quality and is accurate to di‐agnose significant stenosis and occlusion of CABG .