BOLD-fMRI对2型糖尿病患者早期肾脏功能变化的研究

Effect of BOLD-fMRI on early renal function in patients with type 2 diabetes mellitu

目的探讨基于血氧水平依赖的功能MRI(blood oxygenation level dependent functional MRI,BOLD-fMRI)对2型糖尿病(diabetes mellitus,DM)患者早期肾脏功能性缺氧的评估价值。材料与方法将55例2型DM患者按照是否含有微量白蛋白分为单纯DM组27例和早期糖尿病肾病(diabetic nephropathy,DN)组28例,同时招募年龄、性别匹配的30例健康志愿者作为对照组(normal control,NC)。行BOLD-fMRI扫描,计算得到皮质R2^(*)值(cortical R2^(*),CR2^(*))、髓质R2^(*)值(medullary R2^(*),MR2^(*))及髓质/皮质R2^(*)(R2^(*)ratio between medulla and cortex,MCR),进行组内及组间比较分析,并绘制受试者工作特征(receiver operating characteristic,ROC)曲线。结果三组内MR2^(*)值均显著高于CR2^(*)值(P均<0.05)。三组间CR2^(*)值差异无统计学意义(P>0.05);DM组的MR2^(*)值、MCR均显著高于NC组和早期DN组(P均<0.05),而早期DN组与NC组间差异无统计学意义(P>0.05)。MR2^(*)值、MCR及二者联合鉴别NC组与DM组的曲线下面积(area under the curve,AUC)值分别为0.884[95%置信区间(confidence interval,CI):0.802~0.966]、0.802(95%CI:0.690~0.915)和0.891(95%CI:0.811~0.971);鉴别DM组与早期DN组的AUC值分别为0.819(95%CI:0.707~0.931)、0.759(95%CI:0.630~0.889)和0.824(95%CI:0.714~0.934),均具有良好的诊断价值。各指标的诊断效能上差异无统计学意义(P>0.05)。结论BOLD-fMRI可以从氧合水平无创评估DM患者早期的肾脏损害情况,并能监测到在临床尚未出现蛋白尿阶段的肾脏髓质功能性缺氧改变,为临床早期诊断、及时治疗和改善预后提供依据,具有重要的临床价值。

Objective:To explore the value of blood oxygen level-dependent functional magnetic resonance imaging(BOLD-fMRI)in the evaluation of early renal functional hypoxia in patients with type 2 diabetes.Materials and Methods:Fifty-five patients with type 2 diabetes were divided into diabetes mellitus group(DM group,n=27)and early diabetic nephropathy group(DN group,n=28)according to the presence or absence of microalbuminuria.Thirty age-and sex-matched healthy volunteers were recruited as normal control group(NC group).The cortical R2^(*)value(cortical R2^(*),CR2^(*)),medulla R2^(*)value(medullary R2^(*),MR2^(*))and medulla/cortical R2^(*)(R2^(*)ratio between medulla and cortex,MCR)were calculated by BOLD-fMRI program scan.The intra-group and inter-group comparative analysis was performed.Then receiver operating characteristic(ROC)are plotted.Results:The value of MR2^(*)was significantly higher than that of CR2^(*)in the three groups(all P<0.05).There was no significant difference in CR2^(*)among the three groups(P>0.05),but the values of MR2^(*)and MCR in DM group were significantly higher than those in NC group and early DN group(P<0.05),but there was no significant difference between early DN group and NC group(P>0.05).MR2^(*)value,MCR and MR2^(*)+MCR had good diagnostic value in differentiating NC group from DM group,early DM group and early DN group,the AUC values were 0.884[95%(confidence interval,CI):0.802-0.966],0.802(95%CI:0.690-0.915)and 0.891(95%CI:0.811-0.971);0.819(95%CI:0.707-0.931),0.759(95%CI:0.630-0.889)and 0.824(95%CI:0.714-0.934)respectively.There were no significant difference in diagnostic efficacy among all indexes(P>0.05).Conclusions:BOLD-fMRI can non-invasively evaluate the early renal damage in patients with diabetes from the level of oxygenation,and can monitor the functional hypoxia changes of renal medulla in the stage of clinical proteinuria,which provides a basis for early clinical diagnosis,timely treatment and improvement of prognosis,and has important clinical value.