Applications of multi-nuclear magnetic resonance spectroscopy at 7T
Applications of multi-nuclear magnetic resonance spectroscopy at 7T
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DOI：
10.4329/wjr.v3.i4.105
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发表时间：
2011-04-28
影响因子：
2.5
通讯作者：
Morris, Peter G.
中科院分区：
文献类型：
--
作者：
Stephenson, Mary C.;Gunner, Frances;Morris, Peter G.
目的：探讨超高场（7T）在H-1和C-13磁共振波谱（MRS）代谢研究中的优势。方法：在3 t和7T时用H-1 MRS测量脑代谢物，用C-13和H-1 MRS分别测量肌肉中的糖原和脂质。结果：在大脑中，增加的信噪比（SNR）和色散允许氨基酸谷氨酸、谷氨酰胺和γ -氨基丁酸（GABA）的光谱分离，而不需要复杂的编辑序列。这些代谢物的量化在7T时比在3T时得到改善。7T时，谷氨酸、谷氨酰胺和GABA的测量重复性（%变异系数）分别为4%、10%和10%，3T时分别为8%、29%和21%。7T时的测量用于比较前扣带皮层（ACC）和脑岛的代谢物水平。脑岛肌酸和谷氨酸水平明显高于ACC （P < 0.05）。在肌肉中，7T时增加的信噪比和光谱分辨率使运动和再喂养后的糖原（C-13）和心肌细胞内脂质（IMCL）和心肌细胞外脂质（EMCL） （H-1）的交叉研究成为可能。运动后糖原水平显著降低（50% VO2 max时-28%；75% VO2 max时-58%）。有趣的是，尽管运动负荷减少，但腘绳肌的糖原水平与股四头肌的糖原水平相同。研究中未发现IMCL和EMCL的变化。结论：7T时脑和肌肉MRS测量的改善将增加研究人体代谢和病理变化的潜力。(c) 2011年白石登。版权所有。
AIM: To discuss the advantages of ultra-high field (7T) for H-1 and C-13 magnetic resonance spectroscopy (MRS) studies of metabolism.METHODS: Measurements of brain metabolites were made at both 3 and 7T using H-1 MRS. Measurements of glycogen and lipids in muscle were measured using C-13 and H-1 MRS respectively.RESULTS: In the brain, increased signal-to-noise ratio (SNR) and dispersion allows spectral separation of the amino-acids glutamate, glutamine and gamma-aminobutyric acid (GABA), without the need for sophisticated editing sequences. Improved quantification of these metabolites is demonstrated at 7T relative to 3T. SNR was 36% higher, and measurement repeatability (% coefficients of variation) was 4%, 10% and 10% at 7T, vs 8%, 29% and 21% at 3T for glutamate, glutamine and GABA respectively. Measurements at 7T were used to compare metabolite levels in the anterior cingulate cortex (ACC) and insula. Creatine and glutamate levels were found to be significantly higher in the insula compared to the ACC (P < 0.05). In muscle, the increased SNR and spectral resolution at 7T enables interleaved studies of glycogen (C-13) and intra-myocellular lipid (IMCL) and extra-myocellular lipid (EMCL) (H-1) following exercise and re-feeding. Glycogen levels were significantly decreased following exercise (-28% at 50% VO2 max; -58% at 75% VO2 max). Interestingly, levels of glycogen in the hamstrings followed those in the quadriceps, despite reduce exercise loading. No changes in IMCL and EMCL were found in the study.CONCLUSION: The demonstrated improvements in brain and muscle MRS measurements at 7T will increase the potential for use in investigating human metabolism and changes due to pathologies. (c) 2011 Baishideng. All rights reserved.