Magnetic resonance imaging as a sole method for the morphological and functional evaluation of live kidney donors

To evaluate gadolinium-enhanced dynamic magnetic resonance imaging (MRI) as the sole method for the anatomical and functional assessment of potential live-kidney donors.

The study included 50 consecutive kidney donors; in addition to routine donor evaluation, the kidney was imaged with Gd-enhanced dynamic MRI, which was also used for selectively determining the glomerular filtration rate (GFR) of each kidney. All donors had a m99Tc-mercaptoacetyltriglycine (MAG3) renal scan as the reference standard to measure GFR. The anatomical results of MRI were compared with the findings at donor nephrectomy, and the GFR estimated from MRI compared with that from MAG3 scintigraphy.

MR angiography had 100% sensitivity, 94% specificity and 96% overall accuracy for detecting the number of renal arteries, and 100% sensitivity, 98% specificity and 98% overall accuracy for the number of renal veins. There was a close correlation (r = 0.54, P < 0.01) between the GFR of each kidney estimated by MRI or MAG3. For the right and left kidneys the mean isotope clearance was not significantly different from that of mean MRI clearance. MR urography allowed visualization of the urinary tract and the detection of any abnormality.

Gd-enhanced dynamic MRI can provide accurate information about the anatomy of the urinary tract and vasculature of the kidney, and can be used to accurately estimate the selective GFR of each kidney. Therefore, we recommend MRI as a single imaging diagnostic method for assessing potential live kidney donors.