Coronary artery bypass grafts: evaluation of patency with cine MR imaging

This report describes our first experiences in using cine MR imaging to assess the status of a coronary artery bypass graft (CABG). This technique uses a low flip angle, a fast repetition rate, and gradient-refocused echoes to produce images in which the signal of flowing blood within even small vascular structures (e.g., CABGs) is enhanced. Twenty-eight CABGs were evaluated by using both cine MR imaging and coronary angiography (as "gold standard"), and the MR images were interpreted blindly for determination of patency or occlusion of the CABGs. The sensitivity of cine MR imaging for determination of CABG patency was 93%, the specificity was 86%, and the overall predictive accuracy was 89%. Because cine MR imaging facilitates the identification of patent vascular structures by enhancing the signal intensity of flowing blood, this technique seems particularly attractive for noninvasively determining CABG patency.