病毒性脑炎的磁共振成像和扩散加权成像表现

目的探讨病毒性脑炎的核磁共振成像（MRI）和扩散加权成像（DWI）表现。方法71例病毒性脑炎患者,28例颅内有病灶者为A组,43例颅内无病灶者为B组;100例正常成人作为对照组。3组均进行常规MRI及DWI检查,比较病毒性脑炎与正常成人的额叶白质、颞叶白质、侧脑室旁及基底节-丘脑区的平均表观扩散系数（ADC）值的差异。结果 A组病毒性脑炎患者额叶白质、颞叶白质、侧脑室旁及基底节-丘脑区的平均ADC值分别为（1.070±0.21）×10-3mm2/s、（1.110±0.21）×10-3mm2/s、（1.080±0.19）×10-3mm2/s、（1.030±0.18）×10-3mm2/s;B组病毒性脑炎患者额叶白质、颞叶白质、侧脑室旁及基底节-丘脑区的平均ADC值分别为（0.789±0.05）×10-3mm2/s、（0.813±0.04）×10-3mm2/s、（0.789±0.04）×10-3mm2/s、（0.779±0.03）×10-3mm2/s;正常成人的额叶白质、颞叶白质、侧脑室旁及基底节-丘脑区的平均ADC值分别为（0.7961±0.04）×10-3mm2/s、（0.805±0.05）×10-3mm2/s、（0.785±0.03）×10-3mm2/s、（0.770±0.02）×10-3mm2/s。A组的平均ADC值较B组及对照组均升高,差异具有统计学意义（P均〈0.05）,而B组与对照组差异无统计学意义（P均〉0.05）。结论DWI及ADC可反映病毒性脑炎病变组织的微观结构变化信息,是常规MRI非常有价值的补充,与临床诊断相结合,有助于病毒性脑炎的诊断。但在病毒性脑炎早期尚未形成可见的颅内病灶者,MRI包括DWI及ADC对病毒性脑炎的诊断受到限制,尚需进一步探讨。

The application of magnetic resonance imaging and diffusion-weighted imaging in viral encephalitis

Objective To explore the applied value of magnetic resonance imaging（MRI） and diffusion-weighted imaging（DWI） in viral encephalitis.Methods The conventional MR imaging and DWI were performed in 71 patients with viral encephalitis diagnosed by clinical standard and 100 normal adults（control group）,and the former redivided into group A（n=28） and group B（n=43）according to yes or no focus discovered by MRI and CT.The average apparent diffusion coefficient（ADC） values of white matter of frontal lobe and temporal lobe,para-lateral ventricle and basal ganglia-thalamus region were compared in the patients with viral encephalitis and in normal adults.Results The average ADC values of white matter of frontal lobe and temporal lobe,para-lateral ventricle and basal ganglia-thalamus region were（1.070±0.21）×10-3mm2/s,（1.110±0.21）×10-3mm2/s,（1.080±0.19）×10-3mm2/s and（1.030±0.18）×10-3mm2/s,respectively in group A;the values were（0.789±0.05）×10-3mm2/s,（0.813±0.04）×10-3mm2/s,（0.789±0.04）×10-3mm2/s and（0.779±0.03）×10-3mm2/s,respectively in group B;the values were（0.796±0.04）×10-3mm2/s,（0.805±0.05）×10-3mm2/s,（0.785±0.03）×10-3mm2/s and（0.770±0.02）×10-3mm2/s,respectively in control group.The mentioned above values were all higher in the group A than those matched values in group B and control group（all P0.05）,while there was no significant difference between group B and control group（all P0.05）.Conclusions DWI and ADC values can reflect the information of microstructure changes of viral encephalitis and provide supplement informations for MRI.Combined with clinical diagnosis,DWI and ADC greatly contribute to the diagnosis of viral encephalitis,but the diagnostic value is limited due to the visible focus has not arisen in early stage of viral encephalitis and would need further investigation.