小儿流行性乙型脑炎的MR成像及其扩散加权成像特征  

Japanese encephalitis in children:conventional MR imaging and diffusion weighted imaging features

作　　者：严志汉[1] 虞志康[1] 毛传万[1] 白光辉[1] 张弦[1] 蔡志胜[1] 何家维[1] 

机构地区：[1]温州医学院附属第二医院育英儿童医院放射科,325027

出　　处：《中华放射学杂志》2007年第6期633-636,共4页Chinese Journal of Radiology

基　　金：浙江省医药卫生科研项目(2004B147)

摘　　要：目的探讨小儿乙型脑炎的 MRI 表现及其扩散加权成像(DWI)的特征。方法 16例临床诊断符合小儿乙型脑炎的患者,均行头颅常规 MRI 和轴面 DWI,其中7例在发病10 d 内检查,9例在10 d 后检查。观察患者脑 DWI、T_2WI 序列的表现;同时测量感兴趣区的表观扩散系数(ADC)值,并将病灶的 ADC 值与其对应的发病持续时间作相关分析。结果脑部病变区主要呈稍长 T_1、长T_2信号,丘脑受累最常见。16例患者中,15例丘脑受累,其中6例病变仅累及丘脑。7例10 d 内行MR 检查者,病灶在 DWI 较 T_2WI 信号高,而且病变范围更清楚,其中2例在 DWI 还显示了 T_2WI_未能显示的病灶;9例发病10 d 后行 MR 检查者,T_2WI 显示病变较 DWI 清晰。丘脑病灶的 ADC 值与其病程呈正相关(r=0.84,P<0.01)。结论小儿乙型脑炎在 MRI 上常表现为较特征的丘脑受累,结合临床,DWI 对乙型脑炎的早期诊断有一定帮助。Objective To study the conventional MRI and diffusion weighted imaging （DWI） features of Japanese encephalitis （JE） in children. Methods Sixteen patients with JE were included. Conventional MRI and DWI sequences were performed in all patients. Seven patients received MRI within 10 days of onset and 9 after 10 days. The appearances on DWI and T2WI were recorded. The ADC values of lesions were calculated, and then were correlated with the corresponding time interval between onset of neurological symptoms and MRI scanning. Results The lesions of JE mainly showed long T1 and long T2 signal intensity on MRI. The thalami were the most frequently involved areas, and 15 out of 16 showed thalamic involvement and 6 patients only showed thalamic abnormalities without other lesions. Seven patients within 10 days of onset showed lesions with high signal intensity on both DWI and T2WI, but whole or partial lesions showed clearer on DWI than on T2WI, and 2 patients showed extra lesions that were invisible on T2WI. As for the other 9 patients after 10 days of onset, the lesions showed clearer on T2WI than on DWI. There was a direct correlations between thalamic ADC values and the disease duration （ r = 0. 84, P 〈 0. 01 ）. Condusion JE often shows characteristic thalamic involvement on MRI, and DWI is helpful in the early diagnosis of JE.

关 键 词：脑炎 日本 磁共振成像 弥散 

分 类 号：R445.2[医药卫生—影像医学与核医学]