Rapid renal MR fingerprinting for characterizing chronic kidney disease: A feasibility study

The aim of this prospective study was to investigate the feasibility of rapid renal MRF-based quantitative mapping for noninvasive assessment of renal functional and microstructural characteristics in patients with chronic kidney disease (CKD).

Participants with CKD who consented to renal MRF examination were prospectively enrolled from June 2023 to January 2024. T1 and T2 values of the renal cortex and medulla in both kidneys were derived from manually delineated ROIs and compared across CKD groups. Spearman correlation coefficients, following normality testing, were used to examine associations between MRF-derived metrics and serum creatinine (Scr) and measured glomerular filtration rate (mGFR). For participants who underwent renal biopsy, two-way ANOVA was used to compare MRF-derived metrics of biopsied kidney with histopathologic findings.

Fifty-two participants (median age, 49 years [IQR, 39-59 years]) were included, of whom 42 underwent renal biopsy. Higher CKD stages were associated with increased cortical T1 values (P < .001 for the left kidney, P < .0001 for the right kidney, at one-way ANOVA) and higher medullary T2 values (P < .001 for the left kidney, P < .01 for the right kidney, at one-way ANOVA). Scr and mGFR were well correlated with cortical-medullary T1 difference (△T1) of the left kidney (r = -0.543, P = .0004; r = 0.657, P < .0001, respectively). Renal MRF-derived cortical T1, △T1, and whole-kidney T1 showed difference between the low-grade and high-grade renal fibrosis groups (15 % and 20 % fibrosis thresholds, P = .040; 15 % and 30 % fibrosis thresholds, P = .046; and 20 % fibrosis threshold, P = .0264, at two-way ANOVA).

MR Fingerprinting quantitation correlated well with the renal functional and pathological findings, and demonstrated promise for characterizing CKD status.