弥散张量成像对弥漫性轴索损伤的定量研究

A Quantitative Study of Diffuse Axonal Injury Using Diffusion Tensor Imaging

目的:探讨磁共振弥散张量成像(DTI)各向异性分数(FA)对弥漫性轴索损伤(DAI)患者伤情判断及预后评估的价值。方法:DAI患者28例为DAI组,健康志愿者10例为对照组;入院时格拉斯哥昏迷量表(GCS)评价昏迷程度,伤后2周内行MR检查,得到DTI序列影像资料,伤后6个月采用格拉斯哥预后量表(GOS)评估预后;测量感兴趣区(ROI)FA值,比较2组之间FA值、DAI组患侧可视性病灶和健侧对称部位的FA值,并分析DAI组病灶区FA均值与GCS、GOS评分的相关性。结果:DAI组各ROI区FA值显著低于对照组(P<0.01),DAI组各部位可视性病灶区FA值较健侧对称处显著降低(P<0.01),脑干部位(中脑、脑桥及延髓)FA值与GCS、GOS评分正相关(P<0.01),胼胝体FA值与GCS评分正相关(P<0.01)。结论:DTI为诊断DAI病灶的敏感序列,其ROI区FA值变化有助于DAI患者伤情判断及预后评估。

Objective： To investigate the value of fractional anisotropy（FA） of diffusion tensor imaging（DTI） in severity assessment and prognosis prediction of diffuse axonal injury（DAI）.Methods： Twenty-eight patients with DAI（DAI group） and 10 healthy control volunteers（control group） were recruited for the study.Glasgow coma scale（GCS） was used to assess the consciousness of DAI patients at admission.Patients received MR inspection within two weeks after onset and the data of DTI were collected.Glasgow outcome score（GOS） was used to evaluate the patients 6 months later.The fractional anisotropy（FA） values in different regions of interest（ROI） were measured and compared.The correlation between FA values in different ROIs and GCS,GOS scores were analyzed.Results： When compared with the control group,the FA value was significantly decreased in each ROI of DAI group（P0.01）.In DAI group,FA values were significantly lower in the visualized lesions than in the homologous ones in contralateral hemisphere（P0.01）.The FA values in the brainstem（midbrain,pons and medulla oblongata） were positively correlated with GCS and GOS scores（P0.01）.The FA values in the corpus callosum were positively correlated with GCS scores（P0.01）.Conclusion： DTI is a potentially useful imaging modality to detect DAI lesions.Changes of FA value in ROIs help to assess the severity and the outcome of DAI.