Pretransplant assessment of renal viability by phosphorus-31 magnetic resonance spectroscopy. Clinical experience in 40 recipient patients.

A group of 40 cadaveric kidneys was studied just prior to planned transplantation to further assess the applicability of 31P-MRS in the analysis of clinical renal transplant viability. Renal intracellular high-energy phosphorus metabolites (ATP [or NADP], phosphomonoester [PME] and inorganic phosphate [Pi]) and pH were measured noninvasively with MRS surface coils external to cold storage containers. Pretransplant MRS parameters were correlated with subsequent renal function in recipient patients (measured one week postoperatively by the need of dialysis, drop in serum creatinine, urine output, and 123I or 131I Hippuran assessed renal tubular function). ATP and NADP was detected in eleven kidneys and was significantly (P less than 0.001) associated with the best renal function posttransplantation. These kidneys also had the highest PME/Pi ratios (1.66-0.54), while lower ratios (0.36-0.10) were associated with prolonged acute tubular necrosis. The PME/Pi ratios significantly (P less than 0.0001) correlated with subsequent clinical renal function, whereas cold storage times (37 +/- 10 hr) or intracellular renal pH (6.53-7.91) did not. These preliminary data suggest that MRS is a noninvasive, nondestructive and sterile method for assessing clinical viability during hypothermic storage of human cadaver kidneys and the subsequent recovery of renal function postrenal transplantation.