RENAL MAGNETIC-RESONANCE ANGIOGRAPHY IN THE PREOPERATIVE DETECTION OFSUPERNUMERARY RENAL-ARTERIES IN POTENTIAL KIDNEY DONORS

RATIONALE AND OBJECTIVES. Careful evaluation of the renovascular anato my in potential living-related kidney donors is essential regarding th e presence of accessory renal arteries. Conventional arteriography rem ains the standard of evidence for delineating the renal arterial suppl y. We assessed the utility of two-dimensional phase contrast (PC) magn etic resonance angiography (MRA) in the workup of potential living-rel ated renal donors. METHODS. Thirty-nine patients were examined with co nventional arteriography and MRA, which was performed on a 1.5-T syste m using a two-dimensional PC technique in both coronal and axial plane s (repetition time[TR]/echo time [TE] = 39/8.5 msec; flip 60-degrees; matrix 256 x 128; field of view, 28 cm2; 2 excitations; first-order gr adient-moment nulling; 7-mm section with 2-mm overlap). The number of hilar and polar supernumerary renal arteries was determined. Hilar sup ernumerary arteries were classified as co-dominant if they were simila r in size to the ipsilateral main renal artery. RESULTS. Conventional arteriography identified 78 dominant and 13 supernumerary (3 co-domina nt, 10 accessory) renal arteries. Magnetic resonance angiography ident ified the proximal 35 mm of all 78 dominant and the 3 co-dominant rena l arteries. Of the remaining ten (7 polar and 3 hilar) accessory vesse ls, only four were correctly identified with MRA. CONCLUSION. The high error rate (60%) suggests that two-dimensional PC MRA, as implemented , should not be used in the preoperative evaluation of potential renal donors.