Hybrid contrast-enhanced MR angiography of pelvic and lower extremity vasculature at 3.0 T: Initial experience

Purpose: The objective of this study was to describe contrast-enhanced magnetic resonance angiography (MRA) of the lower extremities at 3.0T system for assessment of high resolution images in patients with peripheral arterial occlusive disease (PAOD). Material and methods: 21 Patients with suspected PAOD were examined with four-station MRA at a 3.0T MR system. The MRA protocol consisted of a hybrid technique with two contrast media injections, the first one for visualization of the calf and foot vasculature (non-moving-table technique), the second one for imaging the aortoiliacal and femoral arteries (moving-table technique). For the femoropopliteal and calf station a randomly segmented central k-space ordering (contrast-enhanced timing-robust angiography [CENTRA]) was used. MR-images were analyzed independently by two radiologists with regard to image quality, venous overlap and grade of stenosis. In 6 patients digital subtraction angiography was performed within the following 7 days and evaluated by two radiologists in consensus with regard to the grade of stenosis. The vasculature-tree of each leg was divided in 12 segments, and 3 anatomical regions (iliacal, femoropopliteal, calf/foot). Results: 490 and 488 of 495 arterial segments were visualized with diagnostic image quality by observer I and observer 2, respectively. Image quality was excellent in 470 and 457 arterial segments, respectively. Only 4 segments were rendered as non-diagnostic due to venous overlap. Relevant arterial stenoses (50-99%) were detected in 43 and 47 segments by observer I and observer 2, 66 and 65 arterial segments, respectively, were interpreted as occluded. Conclusion: The hybrid MRA protocol at 3.0T offers high diagnostic quality for the whole peripheral arterial tree without venous contamination at high spatial resolution. (C) 2007 Elsevier Ireland Ltd. All rights reserved.