Pediatric TBI and DAI: Normal Appearing Brain is Not Normal

描述（申请人提供）：我们正在使用两种很有前途的磁共振技术敏感加权成像（SWI）和磁共振波谱成像（MRSI），在TBI后早期获得，以确定它们是否更好地评估TBI的严重程度，通过显示常规MRI显示正常的脑损伤，SWI/MRSI单独或组合将更好地预测3个月和12个月的神经学（NL）和神经心理学（NP）结果。在本修订申请中，我们建议将DTI添加到我们的成像方案中。DTI提供了关于组织水扩散的程度和方向性的额外信息;表观扩散系数（ADC）、各向异性分数（FA）和轴向扩散率（||）所有这些都随着轴突损伤而降低，反映了沿着白色束的水扩散受到干扰，而径向扩散率（）随着损伤而增加，反映了轴突纤维中水扩散的增加。我们将获取3D SWI/MRSI/DTI来评估90名儿童（4-18岁）的11个大脑区域中度/重度（GCS< 13）TBI，受伤后7-17天，90名对照。将在区域、全球（所有区域合并）和3个合并脑区域（皮质、皮质下和后颅窝）对测量值进行比较。我们的目标是：1）证明DTI参数将检测轴突损伤，并与临床指标相比改善3个月和12个月NL/NP结局预测; 2）确定SWI/MRSI/DTI数据单独或组合是否更准确地预测结局;和3）在12个月时重复SWI/MRSI/DTI以分类损伤模式，定义为神经元变性，通过与整体功能结果相关的NAA或DTI参数的间隔变化来测量恢复和可塑性，并探索出血性SWI病变是否仍然存在。目前的成像技术无法识别儿童TBI的程度，因此，这对了解损伤的真实严重程度，做出治疗决策以及能够预测预后具有显著的不利影响。增加DTI将提供额外的直接测量轴突损伤和额外的信息，以评估儿童TBI。 公共卫生相关性：目前的成像技术低估或无法识别儿童TBI的程度，这对了解损伤的真实严重程度有显着的不利影响。扩散张量成像将与其他更灵敏的成像技术（SWI和MRSI）一起使用，以改善可能表现正常的脑损伤检测。我们相信，这项资助的成功将导致TBI后如何评估儿童的范式转变，这将改善神经学结果和生活质量。

DESCRIPTION (provided by applicant): We are using two promising MR techniques Susceptibility- Weighted Imaging (SWI) and Magnetic Resonance Spectroscopic Imaging (MRSI), acquired early after TBI to determine whether they are better at evaluating TBI severity by showing that injury is present in brain that appears normal with conventional MRI and that SWI/MRSI individually or combined will better predict 3- and 12-month neurological (NL) and neuropsychological (NP) outcome. In this revision application, we propose adding DTI to our imaging protocol. DTI provides additional information regarding the degree and directionality of tissue water diffusion; the apparent diffusion coefficient (ADC), fractional anisotropy (FA), and axial diffusivity (||) all of which decrease with axonal injury that reflects disturbed water diffusion along white matter tracts and radial diffusivity () which increases with injury and reflects increased water diffusion across axonal fibers We will acquire 3D SWI/MRSI/DTI to evaluate 11 brain regions in 90 children (4-18 years) with moderate/severe (GCS< 13) TBI, 7-17 days after injury and 90 controls. Measurements will be compared regionally, globally (all regions combined) and as 3 pooled brain regions (cortical, subcortical, and posterior fossa). Our aims are to: 1) demonstrate that DTI parameters will detect axonal injury and improve 3 and 12- month NL/NP outcome prediction compared to clinical indicators; 2) determine whether SWI/MRSI/DTI data individually or in combination are more accurate for predicting outcome; and 3) repeat SWI/MRSI/DTI at 12 months to categorize patterns of injury, defined as neuronal degeneration, recovery and plasticity measured by interval changes of NAA or DTI parameters associated with global functional outcomes and to explore whether hemorrhagic SWI lesions are still present. Current imaging techniques fail to recognize the extent of TBI in children and as a result, this has significant untoward effects regarding understanding the true severity of injury, making treatment decisions and in being able to predict prognosis. Adding DTI will provide additional direct measures of axonal injury and additional information to evaluate children with TBI. PUBLIC HEALTH RELEVANCE: Current imaging techniques underestimate or fail to recognize the extent of TBI in children which has significant untoward effects regarding understanding the true severity of injury. Diffusion Tensor Imaging will be used with other more sensitive imaging techniques (SWI and MRSI) to improve injury detection in brain that may appear normal. We believe that success of this grant will result in a paradigm shift in how children will be evaluated after TBI that will improve neurological outcome and quality of life.