This study evaluates 23Na-MRI and renal injury disease biomarkers in a porcine model of unilateral renal ischemia-reperfusion injury. Pigs were distributed into groups of healthy controls, 2 ischemia times, and three survival times (n = 25). We found a significant difference between thecorticomedullary sodium gradients in pigs exposed to long ischemia. Neutrophil gelatinase-associated lipocalin (NGAL) was increased immediately after the ischemia-reperfusion injury regardless of the length of ischemia, but only remained elevated in the long-time ischemia group. Our results suggest a kidney injury model with the ability to differentiate between reversible and progressive acute kidney injury.