Extent of microstructural white matter injury in postconcussive syndrome correlates with impaired cognitive reaction time: A 3T diffusion tensor imaging study of mild traumatic brain injury
Extent of microstructural white matter injury in postconcussive syndrome correlates with impaired cognitive reaction time: A 3T diffusion tensor imaging study of mild traumatic brain injury
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DOI：
10.3174/ajnr.a0970
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发表时间：
2008-05-01
影响因子：
3.5
通讯作者：
McCandliss, B. D.
中科院分区：
文献类型：
--
作者：
Niogi, S. N.;Mukherjee, P.;McCandliss, B. D.
背景和目的：弥散张量成像（DTI）可能是一个有用的指标的微结构变化牵连在弥漫性轴索损伤（DAI）与持续性脑震荡后症状，特别是在轻度创伤性脑损伤（TBI），传统的MR成像技术可能缺乏敏感性。我们假设对于轻度TBI，DAI的DTI测量值与反应时间的损伤相关，而常规3 T MR成像上的局灶性病变数量与反应时间的损伤无关。材料和方法：34例有持续症状的轻度TBI成人患者，通过量化常规T2* 加权梯度回波图像上检测到的创伤性微血管，并通过DTI测量各向异性分数（FA）在一组先验感兴趣区域内。FA值低于区域平均值2.5 SD，基于26名健康对照成年人的组，被编码为表现出DAI。DTI测量显示了几个主要的损伤区域，包括前放射冠（41%的患者），钩束（29%），胼胝体下束（21%），下纵束（21%），和扣带束（18%）。通过DTI量化的受损白色结构的数量与简单认知任务的平均反应时间显著相关（r = 0.49，P = 0.012）。相比之下，创伤性微血管病变的数量与反应时间无关（r =-0.08，P =.71）。结论：DTI检测到的微结构白色病变与轻度TBI的持续认知功能障碍相关，即使在常规措施不相关的人群中也是如此。因此，DTI测量可以提供与DAI相关的额外诊断信息。
BACKGROUND AND PURPOSE: Diffusion tensor imaging (DTI) may be a useful index of microstructural changes implicated in diffuse axonal injury (DAI) linked to persistent postconcussive symptoms, especially in mild traumatic brain injury (TBI), for which conventional MR imaging techniques may lack sensitivity. We hypothesized that for mild TBI, DTI measures of DAI would correlate with impairments in reaction time, whereas the number of focal lesions on conventional 3T MR imaging would not.MATERIALS AND METHODS: Thirty-four adult patients with mild TBI with persistent symptoms were assessed for DAI by quantifying traumatic microhemorrhages detected on a conventional set of T2*-weighted gradient-echo images and by DTI measures of fractional anisotropy (FA) within a set of a priori regions of interest. FA values 2.5 SDs below the region average, based on a group of 26 healthy control adults, were coded as exhibiting DAI.RESULTS: DTI measures revealed several predominant regions of damage including the anterior corona radiata (41 % of the patients), uncinate fasciculus (29%), genu of the corpus callosum (21 %), inferior longitudinal fasciculus (21 %), and cingulum bundle (18%). The number of damaged white matter structures as quantified by DTI was significantly correlated with mean reaction time on a simple cognitive task (r = 0.49, P =.012). In contradistinction, the number of traumatic microhemorrhages was uncorrelated with reaction time (r = -0.08, P =.71).CONCLUSION: Microstructural white matter lesions detected by DTI correlate with persistent cognitive deficits in mild TBI, even in populations in which conventional measures do not. DTI measures may thus contribute additional diagnostic information related to DAI.