Feasibility of quantitative water T2 mapping for detection of renal tubulointerstitial changes in radiation nephropathy

Motivation: As the current diagnostic tools are insensitive to early kidney damage in radiation nephropathy, there is a clinical need for improved biomarkers that can be used to noninvasively assess tubulointerstitial changes in RN. Goal(s): To verify whether MRI-based T2 mapping can detect microstructural changes in renal parenchyma resulting from radiation-induced kidney damage. Approach: We performed T2 mapping in two mouse models of radiation nephropathy, one involving external beam irradiation and the other utilizing internal irradiation with α-particle-emitting actinium (225Ac) radiolabeled antibody. Results: Increased T2 values were found in the cortex and outer medulla of the treated mice compared to the healthy controls. Impact: MRI-based T2 values could serve as a quantitative biomarker for detecting microstructural changes specific to EBRT and αRPT.