Diabetes and peripheral arterial occlusive disease: Prospective comparisonof contrast-enhanced three-dimensional MR angiography with conventional digital subtraction angiography

OBJECTIVE. The purpose of this study was to compare contrast-enhanced three -dimensional MR angiography with conventional digital subtraction angiograp hy (DSA) for identifying and evaluating arteries of the distal calf and foo t in diabetic patients with severe arterial occlusive disease who will unde rgo distal bypass surgery. SUBJECTS AND METHODS. Twenty-four feet of 24 consecutive patients with diab etes and Limb-threatening lower extremity ischemia were prospectively image d using an ultrafast three-dimensional fast low-angle shot sequence on a 1. 5-T MR scanner. All patients also underwent DSA of the diseased extremity w ithin 5 days. Images were interpreted in a randomized manner by two observe rs in conference. Each lower extremity was divided into seven potential art erial segments. Image analysis included the detection of patent, stenosed, or occluded vessel segments. A vascular surgeon formulated treatment plans on the basis of findings from DSA and then formulated treatment plans on th e basis of findings from both DSA and MR angiography. RESULTS. MR angiography was significantly better than DSA in revealing peri pheral runoff vessels (p < 0.001). In nine (38%) of the 24 patients, MR ang iography showed patent pedal vessels suitable for distal bypass grafting th at were not revealed by DSA. Because of the results of MR angiography, trea tment plans changed in seven of the nine patients in whom patent vessels we re subsequently used as target vessels for distal pedal bypass grafts. CONCLUSION. Contrast-enhanced three-dimensional MR angiography is superior to DSA in revealing patent vessel segments of the foot in diabetic patients with severe arterial occlusive disease. Contrast-enhanced three-dimensiona l MR angiography should be part of the diagnostic algorithm for patients in whom pedal bypass grafting is a therapeutic option.