病毒性脑炎的MRI诊断及临床意义

目的：研究病毒性脑炎的MRI表现特点，探讨MRI对病毒性脑炎的诊断价值。材料和方法：搜集55例经临床诊断为病毒性脑炎的病例，其中男31例。回顾分析其脑部MRI表现。结果：55例中共54例脑部MRI有异常表现。病灶单发或多发，可见于大脑半球、小脑及脑干。大部分病灶不对称分布，少数累及基底节、丘脑病例可对称分布，病灶呈不规则片状或斑片状、点状，可局限于脑皮质或白质，亦可皮髓质同时累及，T1WI呈等、低信号，TWI呈高信号，大部病灶FLAIR呈高信号，部分病程较长者可见软化灶，FLAIR呈低信号。27例增强扫描见8例病灶无强化，19例增强病灶呈不规则片状、环形、结节状及半环形强化。结论：MRI是诊断病毒性脑炎重要的辅助检查方法，具有敏感、准确的优点，结合临床可提高病毒性脑炎的诊断准确率。

Diagnosis and Clinical Significance of Viral Encephalitis on MRI

Purpose: To study the characteristic of viral encephalitis on MRI.Materials and Methods: 55 consecutive cases(31 men and 24 women) with clinical diagnosis of viral encephalitis were reviewed.Patients' MRI of encephalon was retrospectively analyzed.Results: Single or multi - lesions could be seen on hemisphere, cerebellum and brain stem in 54 cases of all. All lesions distributed asymmetry except minority displayed symmetry on basal nuclei area or thalamus. Abnormity pieces, patch or dot lesions could be found in either gray matter or white matter or even both. Lesions showed iso - or low intensity signal on T1WI, high intensity signal on T2 WI and FLAIR. Some cases with a long illness history displayed soft lesions which were low intensity on FLAIR.After administration of contrast medium, 19 cases showed patch, nodule, circular or half - circular shape enhancement with the other 8 cases no enhancement. Conclusion: As one of the important assistant examining methods, MRI has the character of high sensibility and correctness.Combining clinical data and MRI will contribute the dignosis of viral encephalitis.