23Na Magnetic Resonance Imaging in Sepsis-Induced Acute Kidney Injury: A Preclinical Study

Motivation: Currently, there is a lack of research in 23Na-MRI, investigating the renal sodium concentration gradient in Sepsis-Induced acute kidney injury (AKI). Goal(s): This study aimed to investigate sodium concentration changes across the renal parenchyma and to compare them with T1, T2, and T2* alterations as well as kidney perfusion. Approach: 38 mice (N=19 as control and N=19 with septic AKI) were investigated by multi-parametric MRI. Results: In septic AKI, thrombi developed in kidneys and caused renal hypoperfusion. Lack of blood supply to kidneys resulted in sodium retention at cortex and little sodium output at pelvis even in the absence of detectable edema. Impact: This study helps to better understand the radiological pathology of sepsis-induced acute kidney injury in 23Na-MRI. It connects the concept of altered sodium concentration with changes in renal perfusion, T1, T2, and T2* relaxation constants.