Sensitivity of single-voxel 1H-MRS in investigating the metabolism of the activated human visual cortex at 7 T
Sensitivity of single-voxel 1H-MRS in investigating the metabolism of the activated human visual cortex at 7 T
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DOI：
10.1016/j.mri.2005.12.023
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发表时间：
2006-05-01
影响因子：
2.5
通讯作者：
Ugurbil, K
中科院分区：
文献类型：
--
作者：
Mangia, S;Tkác, I;Ugurbil, K
质子磁共振波谱（H-1-MRS）已被用于许多研究中，以非侵入性地评估激活人脑中乳酸的时间变化。然而，结果并不一致。本研究的目的是测试H-1-MRS在功能实验中的灵敏度，在目前可用于人体研究的最高磁场（7 T）。测量的稳定性和再现性进行了评价，从LC模型分析的时间序列的光谱测量过程中的视觉刺激范例，并通过检查在休息和激活过程中获得的光谱之间的差异。对于大多数定量代谢物，检测浓度变化的灵敏度阈值为0.2 μ mol/g。视觉刺激期间代谢物浓度的可能变化在相同范围内（+/- 0.2 μ mol/g）。此外，模拟了由于血氧水平依赖性（BOLD）T2* 变化引起的小的线变窄效应对估计浓度的影响。代谢物的定量通常不受0.5 Hz内线宽变化超过1%的影响。(c)2006年爱思唯尔公司All rights reserved.
Proton magnetic resonance spectroscopy (H-1-MRS) has been used in a number of studies to noninvasively assess the temporal changes of lactate in the activated human brain. However, the results have not been consistent. The aim of the present study was to test the sensitivity of H-1-MRS during functional experiments at the highest magnetic field currently available for human studies (7 T). Stability and reproducibility of the measurements were evaluated from LCModel analysis of time series of spectra measured during a visual stimulation paradigm and by examination of the difference between spectra obtained at rest and during activation. The sensitivity threshold to detect concentration changes was 0.2 mu mol/g for most of the quantified metabolites. The possible variations of metabolite concentrations during visual stimulation were within the same range (+/- 0.2 mu mol/g). In addition, the influence of a small line-narrowing effect due to the blood oxygenation level-dependent (BOLD) T2* changes on the estimated concentrations was simulated. Quantification of metabolites was, in general, not affected beyond 1% by line-width changes within 0.5 Hz. (c) 2006 Elsevier Inc. All rights reserved.