3.0T磁共振DTI和DTT技术对病毒性脑炎的应用研究

目的 探讨磁共振扩散张量成像(DTI)及白质纤维束成像(DTT)技术对病毒性脑炎的临床应用价值. 方法 对25例临床确诊为病毒性脑炎患者(脑炎组)和25例常规MRI检查显示正常的检查者(对照组)行DTI扫描.将DTI扫描数据后处理获得扩散系数(ADC)图、各向异性(FA)图和DTT图,采用ROI测量脑炎组病变区与对照组正常脑组织的ADC值、FA值并对测值进行统计学分析.结果 在病程早期,脑炎组病变区的平均ADC值较对照组明显减低且差异具有显著统计学意义(P＜0.01),而平均FA值较对照组略升高但差异无统计学意义(P＞0.05).在病程中期及晚期,脑炎组病变区平均ADC值较对照组明显升高且差异有显著统计学意义(P＜0.01),平均FA值较对照组明显降低且差异具有统计学意义(P＜0.05).DTT白质纤维示踪成像显示白质纤维主呈浸润性改变,部分纤维中断、缺失,而无推压移位等改变. 结论 DTI与DTT技术能够为病毒性脑炎的诊断及鉴别诊断提供有价值信息.

Application Study of the Diffusion Tensor Imaging and Diffusion Tensor Tractography in Viral Encephalitis at 3.0T Magneton

Objective To analyze the diagnostic value of diffusion tensor imaging(DTI)and diffusion tensor tractography(DTT) in viral encephalitis at 3.0T magneton. Methods 25 patients with viral encephalitis confirmed by clinic and 25 age-match healthy patients were examined by conventional MRI and DTI. The average diffusion coefficient (ADC) map, fractional anisotropy (FA) map and diffusion tensor tractography (DTT) was acquired through image post processing technique. The ADC value, FA value of lesions and normal tissues were measured by region of interest (ROI) with the same standard and the results were statistically analyzed.Results In the acute stage of viral encephalitis: The ADC values were significantly lower than that in normal tissues of control group (P<0.01), FA values of lesions were higher than that of control group and had no statistical significance (P＞0.05). In the subacute and chronic stage of viral encephalitis: The ADC values were higher than that of control group and had statistical significance(P＜0.01), FA values of lesions were significantly lower than that of control group(P<0.05). DTT imaging showed infiltrative changes of white matter fibers in the lesion areas.Conclusion DTI and DTT technique may provide some complementally informations and clinical diagnostic value for viral encephalitis.