Detection of Glutamate Alterations in the Human Brain Using (1)H-MRS: Comparison of STEAM and sLASER at 7 T.
Detection of Glutamate Alterations in the Human Brain Using (1)H-MRS: Comparison of STEAM and sLASER at 7 T.
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DOI：
10.3389/fpsyt.2017.00060
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发表时间：
2017
影响因子：
4.7
通讯作者：
Mandl RCW
中科院分区：
文献类型：
--
作者：
Marsman A;Boer VO;Luijten PR;Hulshoff Pol HE;Klomp DWJ;Mandl RCW
旨在通过 7 T 下的两个短回波时间 (TE) 1H-MRS 序列 [刺激回波采集模式 (STEAM) 和绝热选择性重聚焦 (sLASER) 半定位] 评估人脑中谷氨酸测量的再现性。在研究各种神经系统和神经精神疾病时，谷氨酸的可靠评估非常重要。在 7 T 下，谷氨酸信号可以与谷氨酰胺信号分离，因此与较低场强相比，可以更准确地测量。已开发出 7 T 的 sLASER 序列，使用短 TE 场聚焦，产生的信号是使用 STEAM 获得的信号的两倍，并且由于化学位移伪影减少而提高了定位精度。使用 STEAM 和 sLASER 对 8 名受试者进行了两次扫描。数据是从额叶和枕叶大脑区域获取的。随后，计算估计代谢物浓度的组内相关性。与 STEAM 相比，sLASER 在额叶和枕叶 VOI 中的谷氨酸浓度具有更高的 ICC，这可能是由于其更高的灵敏度和定位精度。我们得出的结论是，7 T 的 sLASER 1H-MRS 是一种可靠的方法，可以以如此高的精度获得人脑中谷氨酸水平的可重复测量结果，甚至可以测量年龄匹配的受试者之间的个体差异。
To assess reproducibility of glutamate measurement in the human brain by two short echo time (TE) 1H-MRS sequences [stimulated echo acquisition mode (STEAM) and semi-localized by adiabatic selective refocusing (sLASER)] at 7 T. Reliable assessment of glutamate is important when studying a variety of neurological and neuropsychiatric disorders. At 7 T, the glutamate signal can be separated from the glutamine signal and hence more accurately measured as compared to lower field strengths. A sLASER sequence has been developed for 7 T, using field focusing at short TE, resulting in twice as much signal as can be obtained using STEAM and improved localization accuracy due to a decreased chemical shift artifact. Eight subjects were scanned twice using both STEAM and sLASER. Data were acquired from the frontal and occipital brain region. Subsequently, intraclass correlations were computed for the estimated metabolite concentrations. sLASER has higher ICC’s for glutamate concentration as compared to STEAM in both the frontal and occipital VOI, which is probably due to the higher sensitivity and localization accuracy. We conclude that sLASER 1H-MRS at 7 T is a reliable method to obtain reproducible measures of glutamate levels in the human brain at such high accuracy that individual variability, even between age-matched subjects, is measured.