A REnal Flow and Microstructure AnisotroPy (REFMAP) MR assessment of renal function: comparison with measured glomerular filtration rate

Motivation: Monitoring and predicting stability of bilateral renal function is necessary for renal cancer patients. Estimated glomerular filtration rate (eGFR), from serum creatinine, provides an estimate of renal function without considering laterality and has demographic biases and limited accuracy. Alternatively, the measured GFR (mGFR) provides more accurate measures of renal function but requires injection of radioactive tracers. Goal(s): We tested the performance of an advanced diffusion-weighted MRI method as a non-invasive alternative for renal function assessment. Approach: Quantitative diffusion-weighted parameters and kidney volumes were used to estimate renal function in renal cancer patients. Results: The MR estimates highly correlated with mGFR of individual kidneys. Impact: We present a diffusion-weighted MR method to assess the function of individual kidneys in a cohort of kidney cancer patients. The technique outputs accurate information complementary to routinely used estimated glomerular filtration rate (eGFR).