功能磁共振成像在早期诊断儿童自身免疫性脑炎及评估患儿预后中的应用价值

Application value of functional magnetic resonance in early diagnosing autoimmune encephalitis in and evaluating the prognosis in children

目的探究功能磁共振成像(functional magnetic resonance imaging,fMRI)对儿童自身免疫性脑炎(autoimmune encephalitis,AE)的早期诊断和预后预测价值。材料与方法选取2018年1月至2019年5月在内蒙古医科大学附属医院收治的50例AE患儿和80例病毒性脑炎(viral encephalitis,VE)患儿分别为作为AE组和VE组,分别进行MRI平扫、磁共振扩散加权成像(diffusion weighted imaging,DWI)、动脉自旋标记(arterial spin label,ASL)灌注成像和波谱分析(1H-magnetic resonance spectroscopy,1H-MRS),其中DWI图像测量病灶区、正常区及两者相对表观扩散系数(relative apparent diffusion coefficient,rADC)值,ASL检测局部脑血流量(relative cerebral blood flow,rCBF),1H-MRS图像检测3.2 ppm附近胆碱(choline,Cho)、2.01 ppm附近N-乙酰天冬氨酸(N-Acetyl-L-aspartic acid,NAA)、3.03 ppm附近肌酸(creatine,Cr)等各标记物及CHo/NAA、Cho/Cr、NAA/Cr波峰下面积,计算标记物面积的相对比值。按照预后不同对VE患儿进行分组,采用SPSS 22.0统计软件包进行数据分析,建立ROC曲线分析各功能参数对VE的诊断价值和对患儿预后的预测价值。结果AE组患儿rADC、NAA/Cr值高于VE组,相对局部脑血流量(relative regional cerebral blood flow,rrCBF)、Cho/Cr值低于VE组,差异具有统计学意义(t=17.979、7.250、4.982、5.174,P<0.05),两组Cho/NAA比较差异无统计学意义(P>0.05);预后不良VE患儿rADC、rrCBF值高于预后良好患儿,NAA/Cr值低于预后良好患儿,差异具有统计学意义(t=2.835、2.282、2.162,P<0.05);rADC、rrCBF、NAA/Cr诊断AE的AUC分别为0.845、0.790、0.868,诊断AE预后不良的AUC分别为0.799、0.706、0.679。结论DWI中的rADC值、ASL中的rrCBF值、1H-MRS中的NAA/Cr值对AE与VE的早期鉴别诊断有一定应用价值,且可能在一定程度上反映AE患儿预后。

Objective:To explore the early diagnostic and prognostic value of functional magnetic resonance imaging(fMRI)in children with autoimmune encephalitis(AE).Materials and Methods:From January 2018 to May 2019,50 children with AE and 80 children with viral encephalitis(VE)who were admitted to the Affiliated Hospital of Inner Mongolia Medical University Hospital were selected as the AE group and the VE group,respectively.MRI scans,diffusion weighted imaging(DWI),arterial spin label(ASL)perfusion imaging and 1H-magnetic resonance spectroscopy(1H-MRS)were performed respectively.The relative apparent diffusion coefficient(rADC)values of the lesion area,the normal area and the two relative ADC values were measured using DWI images,relative cerebral blood flow(rCBF)using ASL,and choline(Cho)near 2.01 ppm,N-Acetyl-L-aspartic acid(NAA)near 2.01 ppm,creatine(Cr)near 3.03 ppm and other markers and the areas under the peaks of CHo/NAA,Cho/Cr,and NAA/Cr using 1H-MRS image;the relative ratio of the area of the markers was calculated.The children with VE were grouped according to the different prognosis,and the SPSS 22.0 statistical software package was used for data analysis.ROC curve was established to analyze the diagnostic value of each functional parameter for VE and the predictive value of the prognosis of the children.Results:The values of rADC and NAA/Cr in the AE group were higher than those in the VE group,and the values of relative regional cerebral blood flow(rrCBF)and Cho/Cr were lower than those in the VE group(t=17.979,7.250,4.982,5.174,P<0.05).There was no significant difference in Cho/NAA between the two groups(P>0.05).The values of rADC and rCBFof children with poor prognosis VE were higher than those with good prognosis,and values of NAA/Cr were lower than those with good prognosis(t=2.835,2.282,2.162,P<0.05).Conclusions:The rADC value in DWI,the rrCBF value in ASL,and the NAA/Cr value in 1H-MRS have a certain application value in the early differential diagnosis of AE and VE,and may reflect the prognosis of children with AE to a certain extent.