Mikkelsen Mark, Singh Krish D, Sumner Petroc, Evans C John
CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom.
Magn Reson Med. 2016 Mar;75(3):946-53. doi: 10.1002/mrm.25699. Epub 2015 Apr 29.
The inhibitory neurotransmitter γ-aminobutyric acid (GABA) can be measured in vivo using edited magnetic resonance spectroscopy (MRS), but quantification suffers from contamination by macromolecules (MM). It is possible to suppress this contamination using symmetric editing, but this procedure potentially compromises reliability of the GABA measurement. The aim of this study was to compare the repeatability of GABA-edited MRS with and without MM suppression.
GABA' (non-MM contaminated) and GABA'+MM (MM-contaminated) concentration was measured in the occipital lobe (OCC) and anterior cingulate (AC) using symmetric and standard editing (n = 15). Each method was performed twice in each region.
Within-participant coefficients of variation for each technique were 4.0% (GABA'+MM) and 8.6% (GABA') in the OCC and 14.8% (GABA'+MM) and 12.6% (GABA') in the AC. Intraclass correlation coefficients were better for the suppression method than standard editing in both the OCC (0.72 versus 0.67) and AC (0.41 versus 0.16). These findings were replicated in the OCC of a second cohort (n = 15).
Symmetric suppression is shown to be comparable in repeatability to standard GABA-editing. Measuring a purer quantification of GABA becomes increasingly important as more research is conducted on links between GABA concentration, pathology and healthy behavior.
抑制性神经递质γ-氨基丁酸（GABA）可通过编辑磁共振波谱（MRS）进行体内测量，但定量受大分子（MM）污染影响。使用对称编辑可以抑制这种污染，但该过程可能会损害GABA测量的可靠性。本研究的目的是比较有无MM抑制情况下GABA编辑MRS的可重复性。
使用对称编辑和标准编辑在枕叶（OCC）和前扣带回（AC）测量GABA'（未受MM污染）和GABA'+MM（受MM污染）的浓度（n = 15）。每种方法在每个区域进行两次。
每种技术在参与者内部的变异系数在枕叶中，GABA'+MM为4.0%，GABA'为8.6%；在前扣带回中，GABA'+MM为14.8%，GABA'为12.6%。在枕叶（0.72对0.67）和前扣带回（0.41对0.16）中，抑制方法的组内相关系数均优于标准编辑。这些结果在第二个队列（n = 15）的枕叶中得到了重复验证。
对称抑制在可重复性方面与标准GABA编辑相当。随着对GABA浓度、病理学和健康行为之间联系的研究越来越多，测量更纯净的GABA定量变得越来越重要。
