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.
目的： 探究磁共振体素内不相干运动扩散加权成像（IVIM-DWI）在鉴别糖尿病患者中糖尿病肾病（DN）和非糖尿病肾病（NDRD）中的价值。 方法： 诊断性试验。2017年10月至 2021年9月前瞻性、连续性纳入在解放军总医院第一医学中心行IVIM-DWI扫描并接受肾脏穿刺活检的2型糖尿患者，测得肾脏皮质、髓质及实质IVIM-DWI参数：灌注分数（f）、纯扩散系数（D）、微循环扩散系数（D*）值，根据肾脏穿刺结果将患者分为DN组和NDRD组。使用Mann-Whitney U检验或独立样本t检验比较两组间的IVIM-DWI参数、临床信息及糖尿病相关生化指标，并通过Spearman相关性分析评估DN组IVIM-DWI参数与DN病理分级、间质病变评分、肾间质纤维化/肾小管萎缩（IFTA）评分、间质炎症评分、血管病变评分、玻璃样变评分及血管硬化评分的相关性，应用受试者工作特征（ROC）曲线评估IVIM-DWI参数对DN与NDRD的诊断效能。 结果： 共27例DN患者及23例NDRD患者纳入了本研究。其中DN组男性19例、女性8例，年龄（52±9）岁；NDRD组男性16例，女性7例，年龄（49±10）岁。相较于NDRD组，DN组具有较高的肾皮质D*值及较低的髓质f值（9.84×10-3 mm2/s比7.35×10-3 mm2/s，Z=-3.65；41.01%比46.74%，Z=-2.29，均P<0.05）。肾髓质D*值与DN分级、间质病变评分及IFTA评分呈负相关（r=-0.571、-0.409、-0.409，均P<0.05）；肾皮质f值与血管硬化评分呈正相关（r=0.413，P=0.032）。在IVIM-DWI相关参数中，肾皮质D*值鉴别DN组与NDRD组的ROC曲线下面积（AUC）为0.802，灵敏度为91.3%，特异度为55.6%。 结论： 基于IVIM-DWI的肾皮质D*值可用于无创鉴别2型糖尿病患者中DN和NDRD，具有辅助临床对糖尿病患者进行无创筛查的潜能。.