Volumetric MRSI Evaluation of Traumatic Brain Injury

描述（由申请人提供）：该项目的长期目标是利用先进的MR神经成像方法改进创伤性脑损伤（TBI）的评估。脑外伤是一个重大的公共卫生问题，目前还没有能够量化损伤严重程度或表明可能后果的客观措施。先前的研究表明，即使在没有显著MRI发现的情况下，磁共振波谱也可以检测到大脑中与损伤程度相关的广泛代谢变化。对于轻度TBI受试者，这代表了这些患者中最大的群体，也是最难评估的，这些弥漫性代谢异常可能幅度很小，尽管广泛存在，而我们也知道，一些大脑区域更容易受到损伤，可能有更多的局灶性异常，特别是在更严重的损伤中。因此，我们假设，通过a)提高检测灵敏度，从大范围的大脑区域采集数据，以及b)与正常值相比，分析局灶性和弥漫性多参数代谢异常，可以改善这类脑损伤的特征。这项试点研究将使用3特斯拉的体积质子磁共振光谱成像（MRSI），使用相控阵检测来表征轻度和中度闭头脑损伤相关的代谢变化。测量将包括n -乙酰天冬氨酸和胆碱，已知对神经元功能障碍和膜转换敏感的代谢标志物。结果将与结构MRI的结果、初步临床评估和结果评估（包括神经心理学测试结果）相关联。核磁共振成像处理方法将纳入核磁共振成像信息，以实现脑区域和组织类型的代谢物分析，以及与正常值进行基于体素的比较。定量的神经成像方法将被开发出来，这些方法将描述：1)哪些大脑部位经历了最大的核磁共振检测到的代谢和结构变化；2)代谢变化的空间范围和程度；3)损伤后6个月，哪些临床和磁共振成像指标与临床预后最相关。假设光谱测量和分析方法的灵敏度和空间覆盖范围的提高将使轻度和中度损伤的特征得到改善，并且代谢神经成像方法将比MRI更敏感地评估这种脑损伤。本研究的相关性：改进影像学评估与弥漫性脑损伤相关的代谢变化，将指导脑外伤后的治疗和患者管理决策，并为损伤的长期后果提供预期。

DESCRIPTION (provided by applicant): The long-term objective of this project is improved evaluation of Traumatic Brain Injury (TBI) using advanced MR neuroimaging methods. TBI represents a major public health problem for which there are currently no objective measures that are able to quantify the severity of injury, or to indicate possible outcomes. Previous studies have shown that Magnetic Resonance Spectroscopy can detect widespread metabolic changes in the brain that correlate with the degree of injury, even in the absence of significant MRI findings. For mild TBI subjects, which represents the largest group of these patients and the most difficult to evaluate, these diffuse metabolic abnormalities may be small in magnitude, though widespread, while it is also known that some brain regions are more susceptible to injury and may have more focal abnormalities, particularly with more severe injury. Therefore, it is hypothesized that improved characterization of this type of brain injury will be obtained by using a) improved detection sensitivity and acquisition from a wide region of the brain, and b) analysis of both focal and diffuse multiparametric metabolic abnormalities, in comparison with normal values. This pilot study will use volumetric proton MR Spectroscopic Imaging (MRSI) at 3 Tesla using phased-array detection, for characterization of metabolic changes associated with mild and moderate closed-head TBI. Measurements will include N-Acetylaspartate and choline, metabolic markers known to be sensitive to neuronal dysfunction and membrane turnover. Results will be correlated with findings from structural MRI, initial clinical assessments, and outcome evaluations, including results of neuropsychological testing. MRSI processing methods will incorporate MRI information to enable metabolite analysis by brain region and tissue type, as well as voxel-based comparisons with normal values. Quantitative neuroimaging measures will be developed that will characterize: 1) which brain locations experience greatest MR-detected metabolic and structural changes; 2) the spatial extent and the degree of metabolic alteration; and 3) which clinical and MR imaging measures best correlate with clinical outcome at 6 months post injury. It is hypothesized that the improved sensitivity and spatial coverage of the spectroscopic measurement and analysis methods will enable improved characterization of mild and moderate injury, and that the metabolic neuroimaging methods will be more sensitive than MRI for evaluation of this brain injury. Relevance of this research: Improved imaging assessment of metabolic changes associated with diffuse brain injury will guide treatment and patient management decisions following brain trauma, as well as providing expectations for long-term consequences of the injury.