[The role of intravoxel incoherent motion diffusion-weighted imaging in distinguishing diabetic nephropathy from non-diabetic renal disease in diabetic patients].

ABSTRACT

Objective: To investigate the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in the differential diagnosis of diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) among patients with type 2 diabetes mellitus (T2DM). Methods: A diagnostic test. In this prospective study, patients with T2DM who underwent both IVIM-DWI and renal biopsy at the First Medical Center of Chinese PLA General Hospital between October 2017 and September 2021 were consecutively enrolled. IVIM-DWI parameters including perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were measured in the renal cortex, medulla, and parenchyma. Patients were divided into the DN group and NDRD group based on the renal biopsy results. IVIM-DWI parameters, clinical information, and diabetes-related biochemical indicators between the two groups were compared using Student's t-test or Mann-Whitney U test. The correlation of IVIM-DWI parameters with diabetic nephropathy histological scores were analyzed using Spearman's correlation analyzes. The diagnostic efficiency of IVIM-DWI parameters for distinguishing between DN and NDRD were assessed using the receiver operating characteristic (ROC) curves. Results: A total of 27 DN patients and 23 NDRD patients were included in this study. The DN group comprised 19 male and 8 female patients, with an average age of 52±9 years. The NDRD group comprised 16 male and 7 female patients, with an average age of 49±10 years. The DN group had a higher D* value in the renal cortex and a lower f value in the renal medulla than the NDRD group (9.84×10-3 mm2/s vs. 7.35×10-3 mm2/s, Z=-3.65; 41.01% vs. 46.74%, Z=-2.29; all P<0.05). The renal medulla D* value was negatively correlated with DN grades, interstitial lesion score, and interstitial fibrosis and tubular atrophy (IFTA) score (r=-0.571, -0.409, -0.409; all P<0.05) while the renal cortex f value was positively correlated with vascular sclerosis score (r=0.413, P=0.032). The renal cortex D* value had the highest area under the curve (AUC) for discriminating between the DN and NDRD groups (AUC=0.802, sensitivity 91.3%, specificity 55.6%). Conclusion: IVIM-derived renal cortex D* value can be used non-invasively to differentiate DN from NDRD in patients with T2DM that can potentially facilitate individualized treatment planning for diabetic patients.