摘要目的 分析成人流行性乙型脑炎的磁共振成像(magnetic resonance imaging,MRI)表现特征,探讨MRI对成人流行性乙型脑炎的诊断价值.方法 2016年8月至2018年9月宁夏医科大学总医院诊治并进行MRI检查的成人流行性乙型脑炎患者32例,均在8月至9月份发病,年龄范围17 ～ 83岁.回顾性分析患者临床资料、实验室检查、MRI各序列的信号表现特征和颅内病灶累及部位.结果 32例患者中,29例(90.6％)急性发病,28例(87.5％)意识不清及认知障碍,26例(81.2％)出现高颅压症状,3例(9.4％)脑膜刺激征阳性,3例(9.4％)出现帕金森样症状,10例(31.2％)出现癫痫症状,15例(46.9％)四肢肌力减低.20例患者乙脑病毒特异性IgM抗体阳性.28例行脑脊液检查,15例(53.6％)颅内压≥180 mmH20(1 mmH20=0.009 8 kPa),7例(25.0％)出现淋巴细胞反应,16例(57.1％)出现混合细胞反应.23例(71.9％) MRI表现阳性,其中累及丘脑17例(73.9％)、海马13例(56.5％)、大脑脚6例(26.1％)、大脑皮层4例(17.4％)、基底节2例(8.7％)、脑干1例(4.3％)和胼胝体压部1例(4.3％).T1加权成像(weighted imaging,WI)、T2WI结果阳性者各21例,T2-液体衰减反转恢复序列(fluid attenuated inversion recovery,FLAIR)结果阳性为23例,弥散加权成像(diffusion weighted imaging,DWI)结果阳性为20例,其中T2-FLAIR、DWI成像结果比T1WI、T2WI显示的病灶更多,病变范围大,且皮层受累范围边界清楚.结论 成人流行性乙型脑炎病变好累及双侧丘脑和海马,T2-FLAIR和DWI更易于显示病灶.颅脑MRI结合流行病学特征、临床表现和实验室检查,对早期诊断具有较好的辅助作用.

abstractsObjective To analyze the magnetic resonance imaging (MRI) images of patients with adult Japanese encephalitis (JE),and to investigate the diagnostic value of MRI for the disease.Methods Thirty-two adult JE patients who underwent cranial MRI at General Hospital of Ningxia Medical University between August 2016 and September 2018 were enrolled.All patients had disease onset between August and September and they aged 17 to 83 years old.The clinical data,laboratory results,MRI signal characteristics of each scanning sequence and the distribution of the brain lesions were retrospectively analyzed.Results Of the 32 adult JE patients,29 (90.6％)cases had acute onset,28 (87.5％) cases had unconsciousness and cognitive impairment,26 (81.2％) cases had intracranial hypertension,3 (9.4％) cases had meningeal irritation,3 (9.4％) cases had Parkinson-like symptoms,10 (31.2％) cases had epilepsy,and 15 (46.9％) cases had decreased muscle strength.Twenty patients were positive for JE virus-specific IgM antibodies.Twenty-eight patients underwent cerebrospinal fluid examination,15 (53.6％) cases showed intracranial pressure ≥180 mmH2O (1 mmH2O =0.009 8 kPa),7 (25％) cases developed lymphocyte reaction,and 16 (57.1％) cases showed mixed cell reaction.Twenty-three cases (71.9％) showed lesions of brain on MRI,including thalamus (17 cases,73.9％),hippocampus (13 cases,56.5％),cerebral peduncle (6 cases,26.1％),cortical and subcortical (4 cases,17.4％),basal ganglia (2 cases,8.7％),brainstem (1 case,4.3％) and splenium of corpus callosum (1 case,4.3％).Positive T1 weight image (T1WI) and T2 weight image (T2WI) results were found in 21 patients,respectively,23 patients had positive T2-fluid attenuated inversion recovery (FLAIR) images,and 20 patients had positive diffusion weighted imaging (DWI) images.Among them,T2-FLAIR and DWI images showed more lesions,wider range of lesions and clearer boundary of cortical involvement range than T1WI and T2WI images.Conclusions Bilateral thalamus and hippocampus are often involved in adult JE.T2-FLAIR and DWI sequences are more sensitive to detect lesions.Combining MRI images with epidemiological characteristics,clinical manifestations,and laboratory tests is of great assistance for early diagnosis of JE.