Feasibility of peripheral contrast-enhanced magnetic resonance angiography at 3.0 tesla with a hybrid technique - Comparison with digital subtraction angiography

Purpose: To prospectively determine feasibility and diagnostic accuracy of 3D contrast-enhanced MR-angiography (CE-MRA) at 3.0 tesla (T) in patients with peripheral arterial occlusive disease. Digital subtraction angiography (DSA) was used as reference standard. Material and Methods: Thirty consecutive patients with suspected peripheral arterial occlusive disease were examined on a 3.0 T MR system by using the integrated whole body coil. A 4-station examination protocol in hybrid technique was chosen, containing 2 gadodiamide injections, the first one for imaging the calf and foot arteries (single-step technique) and the second injection for the visualization of the aortoiliacal and femoral arteries (bolus-chase MRA). All patients underwent DSA within the following 48 hours. The arterial tree of each leg was divided in 15 segments and 4 anatomic regions (iliacal, femoral, popliteal/proximal calf, distal calf/foot). Two radiologists analyzed the MR-images with regard to image quality, grade of stenosis, and venous overlap. DSA-images were analyzed by 2 radiologists in consensus with regard to the stenosis grade. Results: Eight hundred eighty-five and 884 of 889 arterial segments at CE-MRA were rated with excellent or good diagnostic image quality by observer 1 and observer 2, respectively. In only 3 segments image quality was affected by venous contamination. Sensitivity of CE-MRA for determination of relevant arterial stenoses (50%-99%) and occlusions-as compared with DSA-was 95.3% (both observer) and specificity was 98.5% and 97.8% for observer 1 and observer 2, respectively. Conclusion: Peripheral hybrid CE-MRA at 3.0 T is feasible and proved to be reliable at depiction of stenoses and occlusions of the whole pelvic and lower leg arterial system.