弥散张量成像在弥漫性轴索损伤中的应用价值

Application of diffusion tensor imaging in diffuse axonal injury

目的:探讨弥散张量成像(diffusion tensor imaging,DTI)在弥漫性轴索损伤(diffuse axonal injury,DAI)中的临床应用价值。方法:收集临床证实DAI患者40例及正常对照组40例,DAI组于外伤后12、24h及72h常规进行DTI扫描,正常对照组行DTI扫描,测量并记录患者大脑额叶皮质下、胼胝体及脑干处各个时间点的各向异性分数(fractional anistrophy,FA)及表观弥散系数(apparent diffusion coefficient,ADC)的变化,比较FA、ADC与格拉斯哥昏迷评分(GCS)的相关性。结果:DAI患者各个部位、各个时间点的FA值较对照组明显下降(P<0.05),并随时间延长呈逐渐降低趋势;ADC值随时间延长有逐渐降低趋势,但各个部位、各个时间点与正常对照组差异均无统计学意义(P>0.05)。DAI患者各个部位FA值与GCS呈明显负相关(r=-0.729),各个部位ADC值与GCS评分相关性不大(r=0.480)。结论:相对于ADC值,DAI患者FA值更能准确反映轴索损伤程度,与患者GCS评分具有良好相关,能及时反映病情严重程度,值得临床进一步研究。

Objective. To discuss the clinical application value of diffusion tensor imaging （DTI） in diffuse axonal injury （DAI）. Methods： A total of 40 DAI patients who were clinical confirmed and normal control group 40 cases were selected. Diffusion tensor imaging of the DAI group and normal control group was performed in 12 h, 24 h and 72 h after trauma conventionally. Patients variation of fractional anistro- phy （FA） and the apparent coursing together coefficient （ADC） of frontal cortex, corpus callosum and brainstem at all time points were measured and recorded. Correlation of FA and ADC with Glasgow coma scale （GCS） was also analyzed. Results： FA values of each time point and each part of the DAI patients was decreased significantly compared with the control group （P〈0.05）, and they were gradually declined along with prolonged time. ADC values were also gradually declined along with prolonged time, but each part and each time point had no statistical difference （P〈0.05） from the normal control group. DAI pa- tients FA value of each part was significantly negative correlated with GCS （r=-0. 729）. The ADC val- ues of each part had little correlation of the GCS score （r=0. 480）. Conclusions： Compared with ADC val- ues, FA values of the DAI patients can reflect the axon damage degree more accurately. It has more close correlation with the patients＇ GCS score and has response to the illness severity in time. It is worthy fur ther clinical study.