病毒性脑炎的MRI诊断

目的探讨病毒性脑炎MR I表现特点及与急性播散性脑脊髓炎(ADEM)鉴别的可能性。方法分析56例病毒性脑炎及50例ADEM的脑部MR I表现,重点分析病毒性脑炎的脑部MR I表现。结果病毒性脑炎脑内有多发或单发的对称或不对称大片状病灶,主要位于皮层、皮层下及基底节-丘脑区,MR I呈长T1长T2信号,增强扫描27例,显示病灶强化者17例,其中呈大片状或脑回状强化者10例。ADEM则脑内有多发不对称斑点、斑片状病灶,主要位于双侧脑室周围及额颞顶枕叶脑白质区,MR I呈长T1长T2信号,增强扫描20例,显示病灶强化者15例,均为环形或斑点状强化。结论MR I是诊断病毒性脑炎重要的辅助检查方法,可在一定程度上为临床的早期诊断及鉴别诊断提供依据。

MRI Diagnosis of Viral Encephalitis

Objective To study MRI characteristics of viral encephalitis and the possibility of differentiating diagnosis with acute disseminated encephalomyelitis(ADEM).Methods MRI findings in 56 patients with viral encephalitis and 50 patients with ADEM were analysed and emphasized on MR findings of viral encephalitis.Results The abnormal signal lesions were found in 56 patients with viral encephalitis,including multiple or single,symmetrical or asymmetrical large patch shape lesions,the lesions located mainly in cortices,subcortical and basal ganglia and thalami.The lesions appeared as long T_1 and long T_2 on MRI.Enhanced MRI was performed in 27 cases,and demonstrated abnormal enhancement in 17 cases,including large patch or gyrus shape enhancement in 10 cases.Multiple and asymmetrical spot-patch white matter lesions were revealed in the frontal lobe,parietal lobe,occipital lobe,temporal lobe,and periventricular areas with ADEM.The lesions were long T_1 and long T_2 on MRI.Enhanced MRI was performed in 20 cases,and demonstrated abnormal enhancement in 15 cases,peripheral ring-type or patch shape enhancement was observed in all cases.Conclusion MRI is one of the important methods in diagnosis of viral encephalitis,it can provide evidences for early diagnosis and differentiation in the certain degree.