Volumetric MRSI Evaluation of Traumatic Brain Injury

该项目的长期目标是使用先进的脑损伤（TBI）评估技术， MR神经成像方法。TBI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指示可能结果的客观措施。先前 研究表明，磁共振光谱可以检测到广泛的代谢变化， 与损伤程度相关的大脑，即使没有明显的MRI结果。对于轻度TBI 受试者，代表了这些患者中最大的群体，也是最难评估的，这些扩散 代谢异常虽然广泛，但程度可能很小，同时也知道一些代谢异常可能会导致代谢异常。 大脑区域更容易受伤，可能有更多的局灶性异常，特别是 严重受伤。因此，假设这种类型的脑损伤的改善表征将是 通过使用a）改进的检测灵敏度和从脑的宽区域的采集，和B） 与正常值相比，分析局灶性和弥漫性多参数代谢异常。 本试点研究将使用相控阵列在3特斯拉下使用体积质子MR光谱成像（MRSI） 检测，用于表征与轻度和中度闭头TBI相关的代谢变化。 测量将包括N-乙酰天冬氨酸和胆碱，这些已知对以下物质敏感的代谢标志物 神经元功能障碍和膜更新。结果将与结构MRI的结果相关， 初步临床评估和结果评价，包括神经心理学测试结果。MRSI 处理方法将结合MRI信息，以实现脑区域和组织的代谢物分析 类型，以及与正常值的基于体素的比较。定量神经成像测量将 开发将表征：1）哪些大脑位置经历最大的MR检测代谢， 结构变化; 2）代谢改变的空间范围和程度;以及3）临床和MR 在损伤后6个月，影像学测量与临床结果最相关。据推测， 光谱测量和分析方法的改进的灵敏度和空间覆盖范围将 能够改善轻度和中度损伤的表征，并且代谢神经成像方法 会比核磁共振成像更敏感 本研究的相关性：改善了弥漫性脑梗死相关代谢变化的影像学评估 脑损伤将指导脑创伤后的治疗和患者管理决策， 对伤害的长期后果进行预测。

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.