Figure 12c. Preoperative evaluation for epicardial placement of an automatic implantable cardioverter/defibrillator in an 82-year-old man. (a) Axial CT image shows a central filling defect within the proximal left saphenous vein graft (arrow). (b) MPR image of the left coronary graft shows extensive filling defects within the saphenous vein graft (arrow). (c) Virtual endoscopic image of the left-sided saphenous vein graft reveals extensive mural thrombus (arrow) within the graft. This finding places the patient at risk for peripheral embolization with surgical manipulation of the graft.