MR Angiography of the Lower Extremities with a Moving-Bed Infusion-Tracking Technique

Purpose: To assess the value of MR angiography (MRA) with automatic table movement in a consecutive series of patients with peripheral arterial disease. Methods: Seventy-two patients underwent both conventional angiography (CA) and MRA for peripheral arterial occlusive disease. Both techniques were scored in a masked way. Consensus scoring for CA was compared with MRA scoring per observer. If there was a discrepancy in scoring of a segment on MRA and CA, the images were reviewed and a consensus arrived at. Results: Observer A found 7.4% and observer B found 6.5% of the segments could not be analyzed on MRA. Observer A scored 11.4% dissimilar on MRA and CA, observer B 15.2%. In the aortoiliac arteries, this was mainly caused by stents and overestimation of stenoses; in the crural arteries it resulted from underestimation of the stenoses on MRA. Overall sensitivity and specificity for the aortoiliac, femoropopliteal and crural vessels were respectively 90% and 91%, 90% and 96%, 59% and 96% for observer A, and 85% and 91%, 84% and 89%, 68% and 85% for observer B. Conclusion: Although MRA of the lower extremities is a promising technique, improvements still need to be made. In particular, MRA below the knee is suboptimal for clinical use.