Effects of Kidney Perfusion levels on Renal Stiffness and Fluidity measured with Tomoelastography in an MRI-compatible ex-vivo model

Motivation: Tomoelastography allows for early detection of changes in the renal stiffness of various kidney pathologies. However, variations in tissue perfusion can have a strong impact on the assessment of renal stiffness. Goal(s): To characterize the effect of tissue perfusion on renal stiffness and tissue fluidity. Approach: Five ex vivo porcine kidneys were separately perfused in an MRI-compatible normothermic machine perfusion setup and simultaneously examined by Tomoelastography. Results: Our results show a strong positive correlation between increasing tissue perfusion and stiffness in the cortex and medulla of ex vivo porcine kidneys being observed after readily one minute of altered tissue perfusion. Impact: Stiffness is an essential factor in diagnosing renal fibrosis. When the renal vasculature is highly perfused, it can mimic increased stiffness associated with renal fibrosis. Our study emphasizes the strong dependency of renal stiffness and fluidity on perfusion.