Laboratory for Functional and Metabolic Imaging (LIFMET), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Magn Reson Med. 2013 Jun;69(6):1512-22. doi: 10.1002/mrm.24406. Epub 2012 Aug 8.
The recent developments in high magnetic field 13C magnetic resonance spectroscopy with improved localization and shimming techniques have led to important gains in sensitivity and spectral resolution of 13C in vivo spectra in the rodent brain, enabling the separation of several 13C isotopomers of glutamate and glutamine. In this context, the assumptions used in spectral quantification might have a significant impact on the determination of the 13C concentrations and the related metabolic fluxes. In this study, the time domain spectral quantification algorithm AMARES (advanced method for accurate, robust and efficient spectral fitting) was applied to 13 C magnetic resonance spectroscopy spectra acquired in the rat brain at 9.4 T, following infusion of [1,6-(13)C2 ] glucose. Using both Monte Carlo simulations and in vivo data, the goal of this work was: (1) to validate the quantification of in vivo 13C isotopomers using AMARES; (2) to assess the impact of the prior knowledge on the quantification of in vivo 13C isotopomers using AMARES; (3) to compare AMARES and LCModel (linear combination of model spectra) for the quantification of in vivo 13C spectra. AMARES led to accurate and reliable 13C spectral quantification similar to those obtained using LCModel, when the frequency shifts, J-coupling constants and phase patterns of the different 13C isotopomers were included as prior knowledge in the analysis.
最近，随着改进的局部定位和匀场技术的发展，高磁场 13C 磁共振波谱学取得了重要进展，提高了啮齿动物大脑中 13C 活体谱的灵敏度和光谱分辨率，能够分离谷氨酸和谷氨酰胺的几种 13C 同量异位素。在这种情况下，光谱定量中使用的假设可能会对 13C 浓度的测定和相关代谢通量产生重大影响。在这项研究中，时间域光谱定量算法 AMARES（用于精确、稳健和高效光谱拟合的高级方法）应用于在 9.4T 下的大鼠大脑中获得的 13C 磁共振波谱，随后输注 [1,6-（13）C2] 葡萄糖。本工作的目的是：（1）使用 AMARES 验证体内 13C 同量异位素的定量；（2）评估先验知识对使用 AMARES 定量体内 13C 同量异位素的影响；（3）比较 AMARES 和 LCModel（模型谱的线性组合）用于定量体内 13C 谱。当将不同 13C 同量异位素的频率位移、J 耦合常数和相位模式作为分析中的先验知识包含在内时，AMARES 可实现与使用 LCModel 相似的准确可靠的 13C 光谱定量。
