Magnetic resonance angiography in the evaluation of living-related renal donors.

Live-donor kidney donation requires an accurate determination of renal arterial anatomy. Traditionally, conventional angiography has supplied this information. The present study was undertaken to determine the accuracy of magnetic resonance angiography (MRA) compared with conventional angiography (CA) in the evaluation of potential living renal donors. Fifteen potential living renal donors underwent both conventional angiography (midstream aortic injection) and three-dimensional phase contrast MRA. Two overlapping volumes of 64 slices (slice thickness 1.5 mm) were obtained in the axial plane to allow coverage from the celiac trunk to the aortic bifurcation. Conventional angiography demonstrated single renal arteries in 24 kidneys and multiple renal arteries in 6 kidneys. Magnetic resonance angiography demonstrated multiple renal arteries in 5 of the 6 kidneys. The sensitivity of MRA in determining kidneys with multiple renal arteries was 83% (5/6). One kidney with an accessory 2-mm polar artery was incorrectly identified as having a single renal artery by MRA. The overall accuracy of MRA in identifying the number of renal arteries was 97% (29/30). Fibromuscular dysplasia was demonstrated in 2 patients by CA, but was not visualized prospectively by MRA. Based on standard physician and hospital fees for each procedure, use of MRA alone would represent a cost savings of approximately $1900 over CA. Despite its minimally invasive and economic attractions, MRA does not achieve the level of accuracy required to replace CA in the evaluation of potential living kidney donors.