Department of Neuroradiology, University Hospital Giessen and Marburg, Justus Liebig University Giessen, Germany.
Acad Radiol. 2011 May;18(5):584-7. doi: 10.1016/j.acra.2010.12.010. Epub 2011 Mar 5.
At lower magnetic field strengths, regional differences of cerebral metabolite distributions have been described, but these data are controversial. Magnetic resonance spectroscopy at 7 T is expected to deliver high spectral resolution and good differentiation, but there are problems arising at high magnetic field strengths that may diminish spectral quality. Because there have been only a few studies in humans so far, there are no standard values for 7 T concerning regional metabolite distributions and concentrations.
In the present study, the metabolites detectable with (1)H magnetic resonance spectroscopy, N-acetyl-aspartate, choline, and creatine (Cr), were evaluated with a single-voxel sequence. Five voxels were placed in the frontal and parietal white matter and the insular, thalamic, and occipital gray matter.
For N-acetyl-aspartate, the lowest values were found in frontal white matter and the highest in thalamic gray matter. Choline displayed the lowest values in frontal white matter and the highest in insular gray matter. Cr showed the lowest values in frontal white matter and the highest in thalamic gray matter. The highest ratio of choline to Cr was found in parietal white matter and the lowest in thalamic gray matter. The highest ratio of N-acetyl-aspartate to Cr was found in thalamic gray matter and the lowest in frontal white matter.
In the present study, regional cerebral metabolite differences were verified with high-field magnetic resonance spectroscopy. Quantitative values and metabolite ratios could be a basis for further clinical studies.
在较低的磁场强度下，已经描述了脑代谢物分布的区域差异，但这些数据存在争议。7T 磁共振波谱预计将提供高光谱分辨率和良好的区分度，但在高磁场强度下会出现一些问题，可能会降低光谱质量。由于目前只有少数几项在人类中进行的研究，因此关于区域代谢物分布和浓度，7T 还没有标准值。
在本研究中，使用单体素序列评估了（1）H 磁共振波谱可检测的代谢物，包括 N-乙酰天冬氨酸、胆碱和肌酸（Cr）。在额状面和顶状面的白质以及岛叶、丘脑和枕状灰质中放置了 5 个体素。
对于 N-乙酰天冬氨酸，最低值出现在额状面白质中，最高值出现在丘脑灰质中。胆碱在额状面白质中的最低值和在岛叶灰质中的最高值。Cr 在额状面白质中的最低值和在丘脑灰质中的最高值。胆碱与 Cr 的比值在顶状面白质中最高，在丘脑灰质中最低。N-乙酰天冬氨酸与 Cr 的比值在丘脑灰质中最高，在额状面白质中最低。
在本研究中，使用高磁场磁共振波谱验证了脑代谢物的区域差异。定量值和代谢物比值可以为进一步的临床研究提供基础。
