Spiral CT and CT-Angiography of Coronary Grafts: Experimental and Clinical Studies

Using conventional and dynamic computed tomography (CT) the rate of correctly demonstrated patent coronary vein grafts (sensitivity) was reported 80–93%. But the rate of suspected graft occlusions confirmed by angiography (specificity) was only 72–78% (Heuser et al. 1982, Godwin et al. 1983,Muhlberger et al. 1990). The lower specificity was mostly caused by confusing occluded grafts with contrasted cardiac structures, coronary arteries, bronchial arteries and graft stumps. Spiral-CT has the potential to improve specificity due to its multislice capability and to improve sensitivity by using peak contrast scanning. However small diameters, curved and wavy courses of grafts and cardiac motions require special imaging conditions.