病毒性脑炎常规磁共振及弥散加权成像表现分析

The performance of MRI and diffusion-weighted images of viral encephalitis

目的:探讨病毒性脑炎的常规磁共振(MRI)及弥散加权成像(PWI)的影像学表现。方法:回顾性分析经临床确诊的21例病毒性脑炎患儿的常规MRI及DWI表现,比较病毒性脑炎和对侧正常脑组织的表观弥散系数值(ADC)差异有无统计学意义。结果:18例患儿病灶主要累及皮层及皮层下、基底节、丘脑以及中脑;呈斑片状或大片状稍长T1、稍长及长T2信号,T2FLAIR呈稍高信号,增强扫描16例呈轻度斑片样强化;3例患儿常规MRI未见明确异常,仅增强扫描局部轻度强化。DWI呈稍高信号8例,高信号13例,患侧ADC值[(0.54±0.17)×10-3mm2/s]较对侧正常脑组织[(0.92±0.16)×10-3mm2/s]降低,差异具有统计学意义(P<0.05)。结论:DWI能够早期发现病毒性脑炎病灶,应该常规作为病毒性脑炎检查序列,DWI结合传统MRI能较好诊断病毒性脑炎。

Objective To investigate the performance of MRI and diffusion-weighted images of viral encephalitis.Method Retrospectively analyze the performance of MRI and DWI in 21 cases.And compare the viral encephalitis and contralateral normal brain tissue apparent diffusion coefficient values(ADC) whether the difference were statistically significant.Results Lesions(18 patients) involving the cortex and subcortex,basal ganglia,thalamus,and midbrain;the lesion carried slightly long T1,slightly long T2 signal,T2FLAIR was slightly hyperintense,16 cases showed mild patchy enhancement by contrast-enhanced scan,3 patients showed abnormalities in MRI,only contrast-enhanced scan showed local mild enhancement.8 cases was slightly hyperintense in DWI,13 cases of hyperintense.Ipsilateral ADC value[(0.54±0.17)×10-3 mm2/s] were lower compared with the contralateral normal brain tissue[(0.92±0.16)×10-3 mm2/s],the difference was statistically significant(P<0.05).Conclusion DWI can be early detection of viral encephalitis lesions,and should be applied to conventional MRI scan.DWI combined with MRI are better to diagnosis of viral encephalitis.