病毒性脑炎与急性播散性脑脊髓炎的MRI鉴别

目的　探讨病毒性脑炎与急性播散性脑脊髓炎(ADEM)脑部MRI表现及鉴别两种疾病的可能性。 资料与方法　分析47例病毒性脑炎及43例ADEM病例的脑部MRI表现,按疾病分组,分析病灶的分布区域、大小、数目、强化的范围及形态的差别。 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,MRI呈长T1 长T2 信号,增强扫描22例,显示病灶强化者11例,其中呈大片状或脑回状强化者7例。ADEM中脑内有多发对称或不对称斑片状病灶,主要位于双侧脑室周围及额颞顶枕叶白质区,MRI呈长T1 长T2 信号,增强扫描18例,显示病灶强化,呈环形或斑点状强化者13例。两种疾病在病灶的分布区域、大小、强化的范围及形态存在差异(P<0.05);病灶的数目无明显差异(P>0.05)。 结论　综合分析病毒性脑炎及ADEM病例的脑部MRI表现,MRI可在一定程度上为临床的鉴别诊断、治疗方案、治疗监测及评估预后提供依据。

MRI Differentiation of Viral Encephalitis and Acute Disseminated Encephalomyelitis

Objective To evaluate the possibility of differentiation on MRI findings between viral encephalitis and acute disseminated encephalomyelitis (ADEM).Materials and Methods A study was conducted on 47 patients with viral encephalitis and 43 patients with ADEM, in which the differences were evaluated by SPSS10.0 software between the grouped lesions on MRI (T 2WI) according to location, size, number and extension, shape of contrast enhancement of the lesions.Results Abnormal signal lesions were found in 47 patients with viral encephalitis, including multiple or single, symmetrical or asymmetrical large patch shape lesions, the located mainly in cortices, subcortical and basal ganglia and thalami. The lesions carried long T 1 and long T 2 on MRI. Enhanced MRI was performed in 22 cases, and demonstrated abnormal enhancement in 11 cases, including large patch or gyrus shape enhancement in 7 cases. Multiple and symmetrical or 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 18 cases, and demonstrated abnormal enhancement in 13 cases, peripheral ring type or patch shape enhancement was observed in 13 cases. There were significant differences between the two groups in location, size of the lesions, extension and shape of contrast enhancement of the lesions (P<0.05). No difference was found in the number of the lesions.Conclusion Analyzing comprehensively the MRI findings in viral encephalitis and ADEM, to a certain extent, can provide evidences for differentiation, therapy, supervision and prognosis.