Diagnostic pitfalls in postinterventional intraarterial magnetic resonance angiography after recanalization of femoropopliteal arterial occlusions

Abstract

Magnetic resonance (MR)-guided vascular interventions are of increasing interest, and, with the use of contrast-enhanced techniques, intraarterial contrast-enhanced MR angiography (ia-ce-MRA) competes with intraarterial digital subtraction angiography (ia-DSA) for the diagnostic evaluation of the infrainguinal vessel tree. To assess the diagnostic value of ia-ce-MRA and high-resolution T1-weighted (hr-T1w) imaging compared to the gold-standard ia-DSA for residual stenosis and local dissections after femoropopliteal recanalization in patients with peripheral arterial occlusive disease (PAOD). Eight patients with PAOD and short vessel occlusion of their femoropopliteal arteries underwent recanalization and balloon positioning under DSA. Patients were transferred to a short-bore MR scanner. Percutaneous transluminal angioplasty (PTA) was accomplished under MR fluoroscopy. Pre- and postinterventional ia-ce three-dimensional (3D) gradient-echo MRA with gadopentate dimeglumine was performed using the intraarterial introducer sheath. Maximum intensity projections (MIP) and multiplanar reconstructions (MPR) were calculated from the data set. High-resolution T1w images of the angioplasty region before and after dilatation were acquired. Control ia-DSA images were obtained. The postinterventional angioplasty results for stenosis grading were comparable in ia-MRA and ia-DSA. Only two of five local dissections in ia-DSA were visualized with the ia-ce-MRA runs including MIPs and MPRs. To clearly depict dissection, hr-T1w images were needed. Grading of stenotic lesions with ia-ce-MRA after PTA is comparable to ia-DSA. Intraarterial ce-MRA with calculated MIPs and MPRs is only partially sufficient to visualize local dissections after PTA. High-resolution T1w images are required for precise diagnosis of dissections in magnetic resonance tomography.