Sensitivity and specificity of human brain glutathione concentrations measured using short-TE (1)H MRS at 7 T.
Sensitivity and specificity of human brain glutathione concentrations measured using short-TE (1)H MRS at 7 T.
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DOI：
10.1002/nbm.3507
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发表时间：
2016-05
影响因子：
2.9
通讯作者：
Terpstra M
中科院分区：
文献类型：
--
作者：
Deelchand DK;Marjańska M;Hodges JS;Terpstra M
虽然传统上用于测量体内 GSH 浓度的 MR 编辑技术解决了光谱重叠的问题，但它们受到与固有的长回波时间 (TE) 相关的损害。本研究的目的是表征在短 TE 下无需编辑即可量化 GSH 浓度的灵敏度和特异性。该方法是在添加或减去体外 GSH 光谱后，测量体内 STEAM 光谱综合产生的 GSH 浓度变化。来自五个测试对象的光谱经过综合改变以模拟 GSH 信号的变化。为了解释测量之间的不同背景噪声，将重新测试光谱（来自用于生成改变数据的同一个体）和来自其他五个个体的光谱与综合改变的光谱进行比较，以研究量化 GSH 浓度的可靠性。使用 7 T 的 STEAM 光谱，在测试和重新测试研究之间以及小样本 (n = 5) 中的不同群体之间检测到约 20% 的 GSH 浓度差异，具有高精度 (R2 > 0.99) 和确定性 (p ≤ 0.01)。 GSH 浓度的增加和减少均得到可靠定量，对抗坏血酸和 γ-氨基丁酸的定量影响很小。这些结果表明使用短 TE 1H MRS 测量人脑 GSH 浓度的生物学相关变化和差异的可行性。虽然这些结果特定于所使用的实验方法和所达到的光谱质量，但本研究可以作为其他化合物、方法和光谱质量的定量可靠性的类似审查的模板。
Although the MR editing techniques that have traditionally been used for measuring GSH concentration in vivo address the problem of spectral overlap, they suffer detriments associated with inherent long echo times (TE). The purpose of this study was to characterize sensitivity and specificity for quantifying GSH concentration without editing at short TE. The approach was to measure synthetically generated changes in GSH concentrations from in vivo STEAM spectra after in vitro GSH spectra were added to or subtracted from them. Spectra from five test subjects were synthetically altered to mimic changes in GSH signal. To account for different background noise between measurements, retest spectra (from the same individuals used to generate the altered data) and spectra from five other individuals were compared to the synthetically altered spectra to investigate the reliability in quantifying GSH concentration. Using STEAM spectroscopy at 7 T, GSH concentration differences on the order of 20% were detected between test and retest studies as well as between differing populations in a small sample (n = 5) with high accuracy (R2 > 0.99) and certainty (p ≤ 0.01). Both increases and decreases in GSH concentrations were reliably quantified with small impact on the quantification of ascorbate and γ-aminobutyric acid. These results show the feasibility of using short TE 1H MRS to measure biologically relevant changes and differences in human brain GSH concentration. While these outcomes are specific to the experimental approach used and the spectral quality achieved, this study serves as a template for analogous scrutiny of quantification reliability for other compounds, methodologies, and spectral qualities.