The use of computed tomography in the diagnosis of coronary artery bypass graft patency.

In a preliminary evaluation of the use of dynamic computed tomography (CT) for the detection of patent aortocoronary bypass grafts, 30 patients were scanned either during the early postoperative period or after graft patency was determined by angiography. To visualize the proximal grafts, CT scans were taken through the aortic root following an intravenous bolus injection of contrast medium. Patent bypass grafts to the left anterior descending and right coronary arteries were demonstrated in 77.5%, while posterior grafts to the circumflex and obtuse marginal coronary arteries were detected in 40%. With its potential for extracting dynamic events, CT scanning provides a new, noninvasive modality for the diagnosis of patent bypass grafts, which heretofore have only been visualized by selective angiography.