Pelvic and lower extremity arterial imaging: diagnostic performance of three-dimensional contrast-enhanced MR angiography.

Abstract

The diagnostic performance of a three-dimensional MR angiography-based strategy was assessed with regard to its ability to characterize the arterial vasculature from the aortic bifurcation to the lower extremity runoff vessels. A single-injection, two-station protocol in combination with a lower-extremity vascular coil was used. Both conventional digital subtraction angiography and three-dimensional contrast-enhanced MR angiography with a dedicated peripheral vascular coil were performed in 61 patients with suspected peripheral vascular disease. In a prospective analysis, one reviewer evaluated the digital subtraction angiographic images and a second reviewer evaluated the MR angiographic images; both were unaware of the results of the other imaging technique. Each vascular segment (29 segments per patient) was evaluated for the presence of occlusive vessel disease. The following grading system was applied: 0, normal; 1, vessel irregularity with a luminal reduction of less than 10%; 2, mild stenosis (lumen reduction, 10-49%); 3, severe stenosis (lumen reduction, 50-99%); and 4, occlusion (lumen reduction, 100%). In 11 patients surgical graft patency was assessed. MR angiography provided an image quality comparable with that of digital subtraction angiography. Overall sensitivity and specificity for MR angiography were 92% and 96.6%, respectively, for the detection of hemodynamically significant disease and 92.3% and 99.4%, respectively, for the detection of occlusions. Two-station contrast-enhanced three-dimensional MR angiography with a dedicated lower-extremity vascular coil proved effective enough to consider it as a noninvasive alternative to digital subtraction angiography in the assessment of the pelvic and lower extremity arterial vasculature.