流行性乙型脑炎的MRI诊断及临床意义

MRI Diagnosis and Clinical Significance of Japanese Encephalitis

目的探讨流行性乙型脑炎(乙脑)的MRI影像表现和临床应用价值。资料与方法经临床血清学检测确诊的14例乙脑患者。全部行MRI扫描,扫描序列包括:T1-液体衰减反转恢复序列(FLAIR)、T2WI、T2-FLAIR和扩散加权成像(DWI)。分析病灶累及部位和各序列的MRI信号特征。结果病灶单独累及丘脑者3例,累及双侧丘脑同时伴有单个或多个其他部位受累10例,其中大脑脚、基底节、大脑皮层及小脑齿状核受累分别为6、4、2、1例。1例为右侧额叶广泛受累。病灶在T1-FLAIR多数呈低信号,在T2WI呈高信号。DWI上高信号7例,等信号4例,低信号3例。14例在T2-FLAIR上全部呈高信号。2例病灶中合并有出血灶。结论乙脑可以累及多个部位,但以双侧丘脑损害为特征性表现。T2-FLAIR和DWI对乙脑诊断及治疗中随访观察有很高的诊断价值,MRI可作为乙脑的首选影像诊断手段。

Objective To study the MR features and clinical significance of Japanese encephalitis （JE）. Materials and Methods 14 patients with clinically serum examination proved JE underwent MR imaging, the image features and lesion characteristics were retrospectively analyzed. The MR sequences included T1 fluid attenuated inversion recovery （T1 FLAIR） ,T2 weighted image ,T2 FLAIR and diffusion weighted image （DWI） , the location and MRI features of lesions were analyzed. Results MRI revealed lesions only in thalamie in 3 cases. 10 cases showed bilateral thalamic involvement combined with other regions, including 6 cases in caudex cerebri,4 in basal ganglia,2 in cerebral cortex, and 1 case in dentate body of cerebellum respectively. The lesions had hypointensity signal on T1 weighted images and hyperintensity signal on T2 weighted images in most patients. On DWI images, hyperintensity signal in 7 cases, isointensity signal in 4 cases, and hypointensity signal in 3 cases, all of the cases had hyperintensity signal on T2 FLAIR images. Hemorrhage were found in 2 cases. Conclusion The JE can invade multiple brain tissue, and the bilateral thalamic involvement is the conspicuous characteristic. T2 FLAIR and DWI have important value in the diagnosis and follow up during treatment, MRI is suggested to be the first choice in diagnosis of JE.