磁共振弥散张量成像技术对创伤性脑损伤的评价

目的：本研究通过分析不同损伤程度的创伤性脑损伤（TBI）患者弥散张量成像（DTI）动态变化的规律，评价其与临床资料的相关性，探讨其在反映TBI的损伤程度及预后方面的价值。方法：对59例共计89人次的TBI患者和60例对照者行常规MRI、DTI检查。测量对照者及TBI患者（急性期、亚急性期、伤后1~3月）胼胝体、内囊、脑干的FA值、ADC值。比较对照组和TBI患者间以及轻、中重度患者间的差异，将不同时期各观察区的测量值与GCS评分行相关性分析，并在不同预后组之间进行比较。结果：TBI患者多数观察区的FA值呈伤后持续减低趋势，FA值与GCS评分呈明显正相关，预后较差者FA值的减低更为明显。伤后1~3月时胼胝体、内囊处的FA值仍具有上述统计学意义。ADC值在伤后呈双相性改变，与GCS、GOS评分间相关性不及FA值。结论：FA值的减低与TBI患者的损伤程度之间具有良好的相关性，并能提示预后改变。在伤后1~3月时，DTI仍能反映出白质纤维束的损伤。ADC值与损伤程度、预后之间的相关性不及FA值敏感、准确。

Assessment of traumatic brain injury by DTI

Objective: To evaluate the correlation between diffusion tensor imaging(DTI) and clinical scores in traumatic brain injury(TBI),and to explore the value of DTI in evaluating the severity of injury and to predict the prognosis of TBI.Methods: Fifty-nine cases of TBI patients with a total of 89 exams and 60 cases of matched healthy controls underwent conventional MRI and DTI exams.FA and ADC in the corpus callosum,internal capsule,and brainstem of controls and TBI patients in the acute phase,subacute phase,and 1-3 months post-trauma were measured.The data between controls and TBI patients,as well as between mild and moderate-severe TBI groups,were compared.The results of different time points were correlated with the GCS scores respectively.The differences of MRI data between different outcome groups were also analyzed.Results: FA of the majority of the observation sites was significantly reduced in the three post-injury phases of TBI patients.FA positively correlated with GCS scores significantly and the reduction of FA was more significant in poor-outcome group.Even 1-3 months after trauma,FA of the corpus callosum and internal capsule still exhibited significant decrease.ADC presented a biphasic trend with time following trauma,and its correlations with GCS and GOS scores were not as significantly as FA.Conclusion: The decreased FA correlates well with the severity of injury and can indicate the prognosis of TBI patients.Even 1-3 months after trauma,the injury of axons can still be revealed by DTI.The correlations of ADC with the injury severity and prognosis are not as sensitive and accurate as FA.