脑灰质异位的CT及MRI诊断

目的:分析脑灰质异位(HGM)的CT及MRI表现,加深对本病的认识,减少漏诊及误诊的分生。方法:搜集我院经临床、CT和/或MRI证实的HGM17例,CT检查9例,MRI检合5例,CT MRI检查3例,回顾性分析其影像学表现。结果:17例中,单侧12例(左侧8例,右侧4例),其中室管膜下结节型3例,混合型桥带型5例,非室管膜下结节型4例。非室管膜下结节型均为单发,额顶叶、颞顶叶、顶枕叶及半卵圆中心各1例:双侧5例,室管膜下结节型2例,其中1例合并胼胝体发育不全;室管膜下弥漫型2例,其中1例合并四叠体池及枕大池蛛网膜囊肿;非室管膜下弥漫性1例。上述病灶位于脑白质内、侧脑室室管膜下或两省均有,呈结节、团块或条带状,在CT及MRI各序列上均与脑灰质密度或信号相同。结论:HGM在CT及MRI上具有特征性的影像学表现,因MRI为多参数成像,在对不典型及小HGM的检出优于CT。

CT and MRI diagnosis of heterotopic gray matter of brain

Objective:To analyze CT and MRI features of heterotopic gray matter of brain(HGM),improve recognition and reduce missed-and mis-diagnosis of HGM.Methods:17 patients with HGM were included in the study.9 cases wre scanned with CT,5 with MRI,and 3 with both CT and MRI.The CT and MRI features of HGM were evaluated retrospectively.Results:In 17 cases,12 were unilateral with 8 in the left and 4 in the right.Among the 12 cases,3 were subependymal nodular type,5 mixed bridge-belt type and 4 non-subependymal nodular type.The lesion of non-subependymal nodular type was singular,with each in fronto-paritetal lobe,temporo-parietal lobe,parieto-occipital lobe,and semiovale center.5 cases were bilateral HGM,with 2 subependymal nodular type(1 case complicated with callosal agenesis),2 subependymal diffuse type(1 case complicated with arachnoid cyst in quadrigeminal cistern and cistern magna) and 1 non-subependymal diffuse type.All the above-mentioned lesions were located in cerebral white matter or subependymal regions of lateral ventricles or both,which characterized as nodules,irregular masses or strips.HGM presented the same density or signal as cerebral gray matter on CT and every sequence of MRI images.Conclusion:HGM has characteristic features on CT and MRI images.MRI examintion is superior to CT in the detection of atypical and small HGM because of its multi-parameter imaging.