Assessment of intrarenal oxygenation in renal donor with blood oxygenation level-dependent magnetic resonance imaging.

Objective To examine change of the apparent relaxation rate R2* values in living kidney donors after uninephrectomy using blood oxygenation level–dependent magnetic resonance imaging. Methods Between July 2011 and January 2012, 45 kidney donors were enrolled into this study. Blood oxygenation level–dependent magnetic resonance imaging scanning was performed before surgery, 3 and 7 days postoperatively. Participants were followed up for 1 year. Results The R2* values in medulla (mR2*) were significantly greater than that of cortex (cR2*), both in resected kidney and remaining one. cR2* values of the remaining kidney was 17.52 ± 1.36 s −1 and then decrease significantly by 8.97% to 15.95 ± 1.14 s −1 at 3 days ( P −1 at 7 days. No significant modification occurred in mR2* after surgery. Multivariate regression analysis showed that the decrease in cR2* values of the remaining kidney was positively associated with sex (r = 0.418), body surface area (r = 0.307), and preoperative cR2* values (r = 0.659). Comparing with glomerular filtration rate at 7 days, a further increment in the glomerular filtration rate was noted at 1 year in patients with cR2* values decrease of ≥10% at 1 week (62.63 ± 11.69 vs 56.97 ± 7.51 mL/min/1.73 m 2 , P  = .02) but not in the other patients (66.43 ± 10.89 vs 62.78 ± 13.74, P  = .064). Conclusion Kidney donation will induce early, profound oxygenation modification within the renal cortex of the remaining kidney. Donors with cR2* value decrease of ≥10% at 1 week have a more favorable renal function compensation at 1 year.