【摘要】 目的 探讨成人乙型脑炎的MRI表现及DWI早期特点,提高对其的认识。方法 收集经临床确诊32例成人乙型脑炎患者资料,均常规T₁WI、T₂WI扫描、FLAIR序列,28例行DWI检查。其中23例早期（1～7 d内）均应用扩散加权像,分析DWI、ADC图、T₂WI病灶信噪比,同时测感兴趣ADC值。结果 32例中MRI阳性的28例,4例为阴性病例,22例累及丘脑,13例累及中脑黑质,9例累及海马,7例累及基底节,4例累及胼胝体压部,3例累及脑桥,2例累及岛叶,2例伴广泛大脑水肿。其中23例早期DWI显示:3例以细胞毒性水肿为主,12例以血管源性水肿为主,5例为2种水肿共同存在,3例阴性。DWI优于T₂WI 6例,T₂WI优于DWI 9例,DWI和T₂WI显示病灶大小、信号相仿5例。结论 成人乙型脑炎好发于丘脑、中脑黑质和海马。急性期病灶以血管源性水肿为主,全面分析DWI、ADC图和T₂WI细节有助于成人乙型脑炎病灶早期检出及定性。更多还原

【Abstract】 Objective To study the conventional MRI features of adult Japanese encephalitis（JE） and explore the early features of diffusion weighted imaging（DWI）.Methods Thirty-two patients with adult JE were included.MR scanning including T₁ WI,T₂ WI and FLAIR were done in all patients,and DWI in 28 patients.Twenty-three patients received DWI in the early stage（within 1 to 7days）,in which the appearances of DWI were analyzed,ADC graphs were obtained and the signal noise ratio and the ADC values of lesions were calculated.Results Twenty-eight cases were abnormal on MRI,and 4 patients were normal.The lesions of JE involved the thalamus in 22 cases,the substantia nigra of midbrain in 13,kellogg’ s seahorse in 9,the basal ganglia in 7,the splenium corporis callosi in 4,the pons in 6 and the insular lobe in 2,extensive cerebral edema in 2.The early features of DWI in 23 patients showed cytotoxic edema in 2,vasogenic edema in 12,both two edemas existing in 5,and normal in 3.DWI were superior to T₂WI in 6 cases,and T₂ WI were superior to DWI in 9 cases,DWI was similar to T₂ WI in 5 cases on showing the size and signal of the lesions.Conclusion Adult JE often occurs in the thalamus,substantia nigra of midbrain and kellogg’ s seahorse.DWI shows vasogenic edema in the early stage.Comprehensive analysis of DWI,ADC and T₂ WI details helps to early detection and qualitative adult JE lesions.更多还原