Volumetric MRSI Evaluation of Traumatic Brain Injury

描述(由申请人提供)：该项目的长期目标是使用先进的磁共振神经成像方法改进对创伤性脑损伤(TBI)的评估。颅脑损伤是一个重大的公共卫生问题，目前还没有客观的措施能够量化伤害的严重程度，或指示可能的结果。此前的研究表明，即使在没有明显MRI表现的情况下，磁共振波谱也可以检测到大脑中广泛存在的与损伤程度相关的代谢变化。对于轻度颅脑损伤患者来说，这些弥漫性代谢异常的程度可能很小，但范围很广，同时众所周知，一些大脑区域更容易受到损伤，可能有更多的局灶性异常，尤其是在损伤较严重的情况下。因此，假设这种类型的脑损伤的特征将通过使用a)改进的检测灵敏度和从大脑的大范围区域获取，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来获得。这项初步研究将使用3特斯拉的体积质子磁共振光谱成像(MRSI)，使用相控阵检测，以表征与轻度和中度闭合性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，已知的代谢标记物对神经元功能障碍和膜翻转敏感。结果将与结构磁共振结果、初步临床评估和结果评估(包括神经心理测试结果)相关联。MRSI处理方法将结合MRI信息，以实现按大脑区域和组织类型进行代谢物分析，以及基于体素与正常值的比较。将开发定量的神经成像测量方法，其特征是：1)哪些脑部位置经历了最大的MR检测到的代谢和结构变化；2)代谢改变的空间范围和程度；以及3)哪些临床和MR成像测量方法与损伤后6个月的临床结果最相关。假设光谱测量和分析方法的灵敏度和空间覆盖率的提高将使轻、中度损伤的特征得到改善，代谢神经成像方法在评估这种脑损伤方面将比MRI更敏感。这项研究的相关性：改进与弥漫性脑损伤相关的代谢变化的成像评估将指导脑损伤后的治疗和患者管理决策，并提供对损伤的长期后果的预期。

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.