DTI各向异性分数与椭球面积比在儿童特发性全面性癫痫中的比较研究

A comparative study between fractional anisotropy and ellipsoidal area ratio of idiopathic generalized epilepsy in children using diffusion tensor imaging

目的:探讨DTI各向异性分数(FA)和椭球面积比(EAR)在特发性全面性癫痫(IGE)中的诊断价值。方法:根据脑电图对发作间期痫样放电(IED)的定侧结果,将33例IGE患儿分为3组,IGE-A组15例(双侧IED),IGE-B组9例(左侧IED),IGE-C组9例(右侧IED)。将32例健康志愿者纳入对照组(NC),并根据年龄、性别分别与A、B、C组相匹配的方法,进一步分为NC-A组、NC-B组和NC-C组,显示阈值为50个体素(Px)。结果:IGE-A和NC-A组比较,FA和EAR异常分布最大区域为左侧半球额叶和颞叶脑白质,EAR异常还见于右中央颞区(222 Px)、顶叶(198 Px)、脑下回(126 Px)、中央后回(125 Px)等右侧大脑半球白质区域。与NC-B组比较,IGE-B组的FA和EAR异常分布区位于左侧大脑白质梭状回和枕叶,此外左额叶(65Px)白质内有少量EAR异常区域。IGE-C与NC-C组比较,FA和EAR异常改变均位于左侧大脑半球,EAR异常区的体素簇范围较FA体素簇大(169 vs.50 Px),EAR图还显示了左侧颞叶(123 Px)、左侧颞中回(112 Px)和颞上回(111 Px)等部位白质及灰质的异常改变。结论:EAR和FA均可反映IGE脑白质异常,EAR比FA更敏感,能发现更多白质异常区域,可用于人类脑部病变的研究。

Objective:To compare and further evaluate the diagnosis performance of fractional anisotropy(FA)and ellipsoidal area ratio(EAR)indices in children of idiopathic generalized epilepsy(IGE).Methods:Diffusion tensor images(DTI)were obtained from three IGE groups according to the EEG results of 33 children with IGE.15 children with bilateral interictal epileptiform discharges(IED)were included in group A,9 children with left IED and 9 children with right IED were included in group B and group C,respectively.Thirty-two healthy children(normal control group,NC)were subdivided into three groups(NC-A,NC-B and NC-C)and compared with the three corresponding IGE groups.FA and EAR were estimated through voxel-based analysis.Statistics results for group analysis were compared among the three IGE groups and age-and sex-matched NC groups.Results:Compared with NC-A group,both FA and EAR abnormalities were found in the white matter(WM)of left cerebrum of including frontal and temporal lobes in IGE-A group,and EAR abnormalities were also shown in the WM of right cerebrum,including rolandic_oper_R(222 Px),parietal lobe(198 Px),Sub-Gyral(126 Px)and postcentral gyrus(125 Px).Compared with NC-B group,reduction of FA and EAR was found in the left fusiform and occipital lobe of the WM.EAR also revealed reductions in the left frontal lobe(65 Px).In group C,the abnormalities in the left cerebrum were revealed both in FA and EAR indices.The cluster size was bigger on EAR images(169 Px)than that on FA images(50 Px).EAR also revealed differences in the left temporal lobe(123 Px),temporal_mid_L(112 Px)and superior temporal gyrus(111 Px).Conclusion:EAR and FA can reflect WM abnormalities in children with IGE,while EAR is more sensitive in detecting WM alterations than FA,which can be used for the study of human brain diseases.