IVIM评估不同尿白蛋白排泄率2型糖尿病患者肾功能损伤的价值

Evaluation of Renal Impairment Using IVIM in Type 2 Diabetes Mellitus with Different Urinary Albumin Excretion Rates

目的探讨体素内不相干运动(IVIM)对不同尿白蛋白排泄率2型糖尿病(T2DM)患者肾功能损伤的评估价值。方法选取临床确诊的T2DM患者46例,根据24 h尿微量白蛋白(UMA)水平将其分为正常白蛋白尿(NAU)组和微量白蛋白尿(MAU)组,同时纳入性别、年龄相匹配的33名健康志愿者作为正常对照组。所有受试者均行腹部IVIM扫描,分别测量双肾皮、髓质的真实扩散系数(D),假性扩散系数(D*)和灌注分数(f)。采用单因素方差分析、χ^(2)检验、秩和检验比较各组受试者临床资料的差异;采用配对样本t检验比较左、右侧肾脏IVIM参数及肾脏皮、髓质之间各参数值的差异;采用单因素方差分析比较多组间IVIM参数值的差异;采用Pearson相关分析比较IVIM参数值与生化指标的相关性。结果NAU组、MAU组的体重、体重指数(BMI)、体表面积(BSA)较对照组明显升高(P均<0.05);MAU组血清肌酐(SCr)升高,肾小球滤过率估计值(eGFR)显著减低,与对照组(P<0.05,P<0.05)、NAU组(P<0.001,P<0.01)差异显著。同组受试者肾皮质D值、f值高于髓质,髓质D*值高于皮质(P均<0.01)。NAU组肾皮、髓质D值、皮质f值较对照组明显升高(P均<0.05)。MAU组肾皮、髓质D值、f值及髓质D*值均明显减低,与对照组、NAU组差异显著(P均<0.05)。肾皮、髓质D值、皮质f值与eGFR呈正相关,与SCr、24 h UMA呈负相关(P均<0.05)。结论IVIM能够无创评价不同肾功能阶段T2DM患者肾脏的水分子扩散、微循环灌注变化特点,这有助于临床早期发现和客观评估肾脏损害的严重程度。

Objective To evaluate the application of intravoxel incoherent motion MRI(IVIM)in detecting the renal function in type 2 diabetics with different urinary albumin excretion rates.Methods A total of 46 T2 DM patients were divided into normoalbuminuria(NAU)group and microalbuminuria(MAU)group based on the absence or presence of microalbuminuria,a cohort of 33 healthy volunteers were included as control group.All of the subjects underwent IVIM examination.The IVIM parameters(D,D*,f)in the cortical and medullary were measured.One-way ANOVA,Chi-square test and rank sum test were used to compare the differences in clinical data.A paired t test was used to compare the differences of IVIM parameters between the left and right kidneys,also the cortical and medullary.The differences of IVIM parameters between the groups were compared by the One-way ANOVA.Pearson correlation analysis was used to compare the correlation between IVIM parameters and biochemical indexes.Results The body weight,BMI and BSA of NAU and MAU groups were significantly higher than those of control group(all P<0.05).The Scr increased,while eGFR decreased in the MAU group,which were significantly different from control group(P<0.05,P<0.05)and NAU group(P<0.001,P<0.01).The values of D and f in the renal cortex were higher than those in the medulla,and D*in the medulla were higher than those in the cortex(all P<0.01).The values of D in the cortex and medulla and f in the medulla were significantly higher in the NAU group than control group(all P<0.01),while compared with the control and NAU group,the values of D and f in the cortex and medulla,and D*in the medulla in MAU group were significantly lower(all P<0.05).The D and f values in the cortex and medulla,f values in the cortex were positively correlated with eGFR,and negatively correlated with Scr and 24 h UMA(all P<0.05).Conclusion IVIM can noninvasively evaluate the characteristics of water molecular diffusion and microcirculation perfusion in patients with T2 DM at the different stages of the renal function,which is helpful early detection and objective assessment of the severity of renal impairment.