Department of Biomedical Engineering at Carnegie Mellon University and Medical Scientist Training Program (S.K.), University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
Department of Radiology (A.G.), Banner Health and Hospital Systems, Mesa, Arizona.
AJNR Am J Neuroradiol. 2019 Jul;40(7):1117-1123. doi: 10.3174/ajnr.A6087. Epub 2019 Jun 13.
Cognitive deficits are among the most commonly reported post-concussive symptoms, yet the underlying microstructural injury is poorly understood. Our aim was to discover white matter injury underlying reaction time in mild traumatic brain injury DTI by applying transport-based morphometry.
In this retrospective study, we performed DTI on 64 postconcussive patients (10-28 years of age; 69% male, 31% female) between January 2006 and March 2013. We measured the reaction time percentile by using Immediate Post-Concussion Assessment and Cognitive Testing. Using the 3D transport-based morphometry technique we developed, we mined fractional anisotropy maps to extract the common microstructural injury associated with reaction time percentile in an automated manner. Permutation testing established statistical significance of the extracted injuries. We visualized the physical substrate responsible for reaction time through inverse transport-based morphometry transformation.
The direction in the transport space most correlated with reaction time was significant after correcting for covariates of age, sex, and time from injury (Pearson = 0.44, < .01). Inverting the computed direction using transport-based morphometry illustrates physical shifts in fractional anisotropy in the corpus callosum (increase) and within the optic radiations, corticospinal tracts, and anterior thalamic radiations (decrease) with declining reaction time. The observed shifts are consistent with biologic pathways underlying the visual-spatial interpretation and response-selection aspects of reaction time.
Transport-based morphometry discovers complex white matter injury underlying postconcussive reaction time in an automated manner. The potential influences of edema and axonal loss are visualized in the visual-spatial interpretation and response-selection pathways. Transport-based morphometry can bridge the gap between brain microstructure and function in diseases in which the structural basis is unknown.
认知缺陷是最常见的脑震荡后症状之一，但对其潜在的微观结构损伤知之甚少。我们的目的是通过应用基于转运的形态计量学发现轻度创伤性脑损伤 DTI 中反应时间背后的白质损伤。
在这项回顾性研究中，我们对 2006 年 1 月至 2013 年 3 月期间的 64 名脑震荡后患者（10-28 岁；69%为男性，31%为女性）进行了 DTI 检查。我们通过即时脑震荡后评估和认知测试测量反应时间的百分位数。使用我们开发的 3D 基于转运的形态计量学技术，我们从分数各向异性图中提取与反应时间百分位数相关的常见微观结构损伤，以自动方式进行提取。置换检验确定了提取损伤的统计学意义。我们通过反向基于转运的形态计量学变换来可视化负责反应时间的物理基质。
在对年龄、性别和受伤时间等协变量进行校正后，与反应时间相关性最强的转运空间方向具有统计学意义（Pearson = 0.44， <.01）。使用基于转运的形态计量学对计算出的方向进行反转，说明了胼胝体（增加）和视辐射、皮质脊髓束和前丘脑辐射（减少）中分数各向异性的物理位移与反应时间的降低有关。观察到的位移与反应时间的视觉空间解释和反应选择方面的生物学途径一致。
基于转运的形态计量学以自动方式发现脑震荡后反应时间背后的复杂白质损伤。在视觉空间解释和反应选择途径中可以观察到水肿和轴突丢失的潜在影响。基于转运的形态计量学可以弥合大脑微观结构和功能之间的差距，而疾病的结构基础尚不清楚。
