Effects of Ischemia-Reperfusion Injury on 23Na Relaxation Times and Its Implications on Quantification of Corticomedullary Sodium Concentration by 23Na MRI

Bharath Atthe¹, Andriy Babsky¹, Navin Bansal¹

²³Na MRI and MRS are applied to evaluate the effects of renal ischemia and reperfusion on ²³Na MRI signal intensity (SI), relaxation times and [Na⁺] in the medulla and cortex of rat kidney. ²³Na relaxation times were found to be similar in renal medulla and cortex in the normal kidney. Ischemia caused a significant decrease in the relaxation times which affected the calculation of [Na⁺] from MRI data. However, the changes in relaxation times for the medulla and cortex were identical, thus the medulla to cortex ²³Na SI ratio represents [Na⁺] ratio in the two compartments during ischemia and reperfusion.