Two-dimensional MR Spectroscopic Characterization of HE

超出提供的空间。这项应用的主要目标是评估一种定位的二维(2D)磁共振波谱技术(MRS)，并明确检测肝性脑病(HE)的脑代谢产物。早期改变的检测在HE的诊断中是非常关键的。局部化磁共振波谱是一种主要的生化工具，用于表征人体组织中的几种非侵入性代谢物。已经报道了HE和其他病理的优秀的一维(1D)磁共振谱，结果令人振奋。然而，各种代谢物的光谱重叠一直是传统的1DMRS谱分析的主要问题，某些代谢物，即谷氨酸、谷氨酰胺、GABA、肌醇、天冬氨酸、谷胱甘肽以及NAA和NAAG的天冬氨酸基，在1.5T处严重重叠而变得复杂。2DMRS似乎非常适合于解决这种重叠问题。它使核磁共振在生物大分子中的应用发生了革命性的变化。之前，其他研究人员试图实现二维磁共振技术的局部化版本，主要使用幻影解决方案，尽管一些结果是从动物大脑中报道的，使用的是非局部化2D技术。除了1DMRS已成功归属和分析的主要代谢物外，还有更多的代谢物尚未被检测到，它们在不同病理机制中的作用还有待用2D MRS来探索。本工作需要检验的一个主要假设是，在HE患者中，使用定位的2D COSY能否比传统的1DMRS更明确地检测到脑内谷氨酰胺/谷氨酸、肌醇、天冬氨酸、GABA和其他脑代谢物的变化。本项目的三个具体目标是：1)获得HE患者前扣带和基底节区域基于单体素的2D COSY谱；2)记录HE患者整体苍白球Mill的变化；3)对HE患者进行神经精神功能和神经认知功能评估，并与神经心理、血氨、肝功能检查结果进行多元回归分析。带有双侧表面“接收”线圈的1.5T核磁共振扫描仪(MRI设备公司)与身体射频“发射”线圈相结合，将实现更好的信号检测。最小的光谱重叠导致谷氨酸/谷氨酰胺、GABA、肌醇、苏氨酸、葡萄糖、牛磺酸和谷胱甘肽的较少模糊归属和更好的定量，将是这项工作的主要结果。表演网站========================================Section End===========================================

EXCEED THE SPACE PROVIDED. The major goals of this application are to evaluate a localized two-dimensional (2D) MR spectroscopic technique (MRS) and to detect cerebral metabolites unequivocally in hepatic encephalopathy (HE). Detection of early changes is very critical in the diagnosis of HE. Localized MR Spectroscopy is a major biochemical tool in characterizing non- invasively several metabolites in human tissues. Excellent one-dimensional (1D) MR spectra of HE and other pathologies have been reported with promising results. However, spectral overlap of various metabolites has been a major concern with the conventional 1D MRS. Spectral analysis of certain metabolites, namely glutamate, glutamine, GABA, myo-inositol, aspartate, glutathione, and the aspartyl groups of NAA and NAAG, has been complicated by severe overlap at 1.5T. 2D MRS seems well suited to address this problem of overlap. It has revolutionized the applications of NMR in biological macromolecules. Previous attempts by other researchers to implement the localized versions of the two-dimensional MR techniques mainly used phantom solutions, although some results were reported from animal brains using a non-localized 2D technique. In addition to the major metabolites successfully assigned and analyzed so far with 1D MRS, more metabolites are yet to be detected and their respective roles in different pathologiesare yet to be explored using 2D MRS. A major hypothesis to be tested in this work is whether the changes of glutamine/glutamate, myo-inositol, aspartate, GABA and other cerebral metabolites can be detected using the localized 2D COSY more unambiguously in HE than the conventional 1D MRS. Three specific goals of this project will be: 1) to acquire the single-voxel based 2D COSY spectra in the anterior cingulate and the basal ganglia regions of HE patients; 2) to record the global pallidal Mill changes in HE patients; 3) to perform the neuropsychiatric and neurocognitive assessment in HE patients, and to correlate the MR findings with the neuropsycho-logical, blood ammonia and liver function test results using multivariate regression analysis. AGE 1.5T MRI scanner with a bilateral surface "receive" coil (MRI Devices Corp.) in combination with a body rf "transmit" coil will be used to achieve improved signal detection. Minimal spectral overlap leading to less ambiguous assignment and better quantitation of glutamate/glutamine, GABA, myo-inositol, threonine, glucose, taurine and glutathione, will be a major outcome of this work. PERFORMANCE SITE ========================================Section End===========================================