急性播散性脑脊髓炎的脑部MRI表现

目的 探讨急性播散性脑脊髓炎(ADEM)的脑部MBI表现特点。资料与方法符合临床诊断标准的ADEM患者9例,在症状出现后1个月内行MRI平扫及增强扫描,采用自旋回波(SE)或快速自旋回波(FSE)序列,常规行横轴位、矢状位及冠状位扫描。结果 (1)病变主要位于大脑白质内,其中累及半卵圆中心及侧脑室旁白质9例。(2)大脑半球内病灶特点为多发且分布不均匀,4例在侧脑室旁可见“垂直征”。(3)8例呈大小不等的片状合并部分点状分布,1例点状分布为主。(4)均表现为TlWI低信号,T2WI高信号。(5)9例注射Gd-DTPA后,7例可见显著异常强化,其中4例以环形强化为主,3例为点片状强化,另2例未强化。(6)4例急性期见灶周水肿,其中2例有占位效应。结论ADEM的脑部MRI表现有一定的特征性,MRI具有重要诊断价值。

MRI Manifestations of Acute Disseminated Encephalomyelitis

Objective To discuss cerebral MRI features of acute disseminated encephalomyelitis (ADEM). Materials and Methods Plain and enhanced MRI scanning was performed in 9 cases with ADEM within one month after the patient developed clinical symptoms. Using SE or FSE sequences, axial, sagittal and coronal scanning was accomplished. Results (1) The lesions were mainly located in cerebral white matter, with semiovale centrum and the white matter by lateral ventricles being involved in 9 cases. (2) In hemisphere, the lesions were multiple and unevenly distributed. "Perpendicular sign" by lateral ventricle was seen in 4 cases. (3) The lesions were manifested as irregular patchy with spotted shadow ( n = 8), or mainly spotted shadow (n = 1). (4) The lesions were presented as low signal on T1WI and high signal on T2WI. (5) After injection of Gd-DTPA, marked enhancement was seen in 7 cases, presenting as ring-shaped ( n = 4) or spotted ( n = 3) enhancement. The remaining two cases showed no enhancement. (6) Perifocal edema was seen in 4 cases during acute stage, 2 of which showed space-occupying effect. Conclusion ADEM carries certain characteristics on MRI. MRI is of great value in its diagnosis.