Renal Ischemia and Reperfusion Assessment With Three-Dimensional Hyperpolarized 13C, 15N2-Urea

Purpose: The aim of this work was to investigate whether hyperpolarized C-13, N-15(2)-urea can be used as an imaging marker of renal injury in renal unilateral ischemic reperfusion injury (IRI), given that urea is correlated with the renal osmotic gradient, which describes the renal function. Methods: Hyperpolarized three-dimensional balanced steady-state C-13 magnetic resonance imaging (MRI) experiments alongside kidney function parameters and quantitative polymerase chain reaction measurements were performed in rats subjected to unilateral renal ischemia for 60-minute and 24-hour reperfusion. Results: We revealed a significant reduction in the intrarenal gradient in the ischemic kidney in agreement with cortical injury markers neutrophil gelatinase-associated lipocalin and kidney injury molecule 1, as well as functional kidney parameters. Conclusion: Hyperpolarized functional C-13, N-15(2) urea MRI can be used to successfully detect changes in the intrarenal urea gradient post-IRI, thereby enabling in vivo monitoring of the intrarenal functional status in the rat kidney. (C) 2016 International Society for Magnetic Resonance in Medicine