The evaluation of coronary bypass graft patency: direct and indirect techniques other than coronary arteriography.

Patients having one or more coronary artery bypass graft operations constitute an important part of the practice of cardiac radiology. Bypass graft patency can be determined by indirect and direct methods. The indirect imaging methods include radionuclide ventriculography, thallium-201 scintigraphy, and positron emission tomography. The direct methods include conventional CT, ultrafast CT, MR imaging, digital subtraction angiography, and Doppler sonography. This review discusses the advantages and limitations of these methods and attempts to define the relative importance of each of these techniques in the evaluation of bypass graft patency.