Assessment of the Added Value of Intravoxel Incoherent Motion Diffusion‐Weighted MR Imaging in Identifying Non‐Diabetic Renal Disease in Patients With Type 2 Diabetes Mellitus

Background Identification of non‐diabetic renal disease (NDRD) in patients with type 2 diabetes mellitus (T2DM) may help tailor treatment. Intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI) is a promising tool to evaluate renal function but its potential role in the clinical differentiation between diabetic nephropathy (DN) and NDRD remains unclear. Purpose To investigate the added role of IVIM‐DWI in the differential diagnosis between DN and NDRD in patients with T2DM. Study Type Prospective. Population Sixty‐three patients with T2DM (ages: 22–69 years, 17 females) confirmed by renal biopsy divided into two subgroups (28 DN and 35 NDRD ). Field Strength/Sequence 3 T/ T2 weighted imaging (T 2 WI), and intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI). Assessment The parameters derived from IVIM‐DWI (true diffusion coefficient [ D ], pseudo‐diffusion coefficient [ D *], and pseudo‐diffusion fraction [ f ]) were calculated for the cortex and medulla, respectively. The clinical indexes related to renal function (eg cystatin C, etc.) and diabetes (eg diabetic retinopathy [DR], fasting blood glucose, etc.) were measured and calculated within 1 week before MRI scanning. The clinical model based on clinical indexes and the IVIM‐based model based on IVIM parameters and clinical indexes were established and evaluated, respectively. Statistical Tests Student's t ‐test; Mann–Whitney U test; Fisher's exact test; Chi‐squared test; Intraclass correlation coefficient; Receiver operating characteristic analysis; Hosmer–Lemeshow test; DeLong's test. P < 0.05 was considered statistically significant. Results The cortex D *, DR, and cystatin C values were identified as independent predictors of NDRD in multivariable analysis. The IVIM‐based model, comprising DR, cystatin C, and cortex D *, significantly outperformed the clinical model containing only DR, and cystatin C (AUC = 0.934, 0.845, respectively). Data Conclusion The IVIM parameters, especially the renal cortex D * value, might serve as novel indicators in the differential diagnosis between DN and NDRD in patients with T2DM. Evidence Level 2 Technical Efficacy Stage 2