单纯疱疹病毒性脑炎的MRI诊断

目的：回顾分析单纯疱疹病毒性（ＨＳＶ）脑炎的ＭＲ成像表现，为临床早期诊断和治疗提供依据。材料和方法：１０例（男４例，女６例；平均年龄３９．５岁）经脑脊液ＰＣＲ证实的ＨＳＶ脑炎患者，采用高磁场（１．０Ｔ）磁共振扫描仪，以自旋回波序列行横断／冠状面Ｔ１加权、质子加权、Ｔ２加权成像和注造影剂后Ｔ１加权成像。结果：１０例中，８例ＭＲ像存在异常信号（广泛、多发、双侧者６例，局灶改变２例）。Ｔ１加权像呈均质低信号５例，该５例在Ｔ２加权像呈均质高信号，提示病理上病灶区坏死，伴周围水肿；３例Ｔ１加权像呈片状低信号内伴脑回状高信号，Ｔ２加权像呈不均质信号，病理上代表出血；增强后Ｔ１加权像呈脑回状强化３例，１例呈结节状改变。结论：以颞叶、岛叶、额底分布为主（尤其为扣带回受累）的多发病灶、伴脑回状出血和强化是ＨＳＶ脑炎的特征性ＭＲ成像表现。不典型表现须与脑瘤、脑梗塞和其它类型病毒性脑炎鉴别诊断。

MRI Diagnosis of Herpes Simplex Virus Encephalitis

Purpose:To analyse retrospectively MR imaging manifestations of HSV encephalitis for providing early diagnosis and therapy in clinically.Materials and Methods:10 cases(male 4 cases,female 6 cases;mean age 39.5 yrs)with HSV encephalitis certified by CSF PCR examination were imaged on MR system with 1.0T superconducted magnets using spin echo sequences for T1-weighted images,PDI,T2-weighted images and T1-weighted images after administration of Gd-DTPA in both axial and corornal planes.Results:MR imaging showed abnormal signals in 8 of 10 cases(extensive,multiple and bilateral in 6 cases,local in 2 cases).In 5 cases,T1-weighted images showed homogeneous low-signal intensity and homogeneous high-signal intensity in T2-weighted images representing pathologically necrotising form with surrounding edema;In 3 cases T1-weighted images showed high signal intensity with a gyriform and T2-weighted images showed a heterogeneous signal pattern suggesting hemorrhage;Enhanced T1-weighted images showed a gyriform enhancement in 3 cases and nodular enhancement in one case.Conclusion:The multiple and extensive involvement with temporal,frontobasal lobes,insulate,especially in the cingulate gyrus,gyriform hemorrhage and enhancement are the characteristic MRI findings in HSV encephalitis.The differential diagnosis include cerebral tumor,cerebral infarction and miscellaneous viral encephalitis.