Multiparametric MRI for Predicting Renal Function Deterioration and Chronic Kidney Disease Development in Patients...

Patients with solid renal masses (SRMs) are at risk of chronic kidney disease (CKD) after surgical resection without a reliable pre-operative predictor.

To investigate whether pre-operative multiparametric MRI (mpMRI) can predict CKD development and progression to stage 3 CKD.

Prospective.

Forty-three participants (female = 13, mean age: 59 ± 12 years) undergoing nephrectomy for SRM.

1.5 T, diffusion-weighted echo-planar imaging (DWI) using nine b-values (0-800 s/mm²), T₁-mapping using variable flip angle, multi-echo gradient-echo blood-oxygen-level-dependent (BOLD), and dynamic-contrast-enhanced MRI (DCE-MRI) using 3D T₁-weighted gradient-echo.

A clinical CKD risk score was calculated from estimated glomerular filtration rate (eGFR), age, diabetes, and surgery (partial or radical nephrectomy). mpMRI parameters included cortical and medullary apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM), tri-exponential diffusion (fast, medium, and slow), and spectral diffusion (vascular, tubule, and tissue) from DWI, native T₁ from T₁-mapping, R₂* from BOLD, and renal plasma flow and eGFR from DCE-MRI. Outcomes were a correlation with baseline eGFR, prediction of postoperative 12-month eGFR decline > 5 mL/min/1.73 m², and stage 3 CKD development (eGFR < 60 mL/min/1.73 m²).

Mann-Whitney U-test and Spearman's rank correlation coefficient (r). Diagnostic ability was determined by leave-one-out cross-validated logistic regression area-under-the-receiver-operator-curve (AUC) and diagnostic odds ratio (DOR) with p-value < 0.05 considered significant.

Thirty of 43 (67%) participants had normal baseline renal function (eGFR ≥ 60 mL/min/1.73 m²). Twenty-nine participants completed 12-month follow-up: among 66% (19/29) who had baseline normal eGFR, 37% (7/19) developed stage 3 CKD. eGFR from DCE-MRI and tubule diffusion correlated with baseline eGFR ( $r^2$ = 0.43 and 0.33 respectively). Reduced vascular diffusion predicted eGFR decline (AUC = 0.75-0.83, DOR = 6.8-16.5). A larger contralateral ADC corticomedullary difference (AUC = 0.89; DOR = 22.5), and clinical CKD risk score (AUC = 0.81; DOR = 5.5) were the strongest predictors of CKD development.

Pre-operative mpMRI predicted post-nephrectomy CKD development. A larger corticomedullary difference in ADC may indicate reduced functional reserve.

1.

Stage 2.