Lymer Katherine, Haga Kristin, Marshall Ian, Sailasuta Napapon, Wardlaw Joanna
Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Royal Edinburgh Hospital, Morningside Park, Edinburgh, UK.
Magn Reson Imaging. 2007 Jun;25(5):634-40. doi: 10.1016/j.mri.2006.10.010. Epub 2006 Nov 30.
We determined the reproducibility of GABA (gamma-aminobutyric acid) measurements using 2D J-resolved magnetic resonance spectroscopy (MRS) on a clinical 1.5-T MR imaging scanner. Two-dimensional J-resolved spectra were acquired in vitro across five GABA concentrations using a volume head coil and a 5-in. surface coil. Additional spectra using a sixth GABA phantom with a very low concentration and from a healthy volunteer were recorded in the 5-in. surface coil only. In each case, the 3.01-ppm GABA resonance was quantified; for comparison, the peak integrals of choline (3.2 ppm) and creatine (3.03 ppm) were recorded. At a physiological concentration (1.2 mM), in vitro GABA measurement was significantly more reproducible in the surface coil than in the volume coil (P=.005), with coefficients of variation (CVs) being less than 16% with the surface coil and up to 68% with the volume head coil. At the smallest concentration of in vivo GABA reported using other spectroscopy techniques (0.8 mM) and detected only using the surface coil, the CV for GABA was 23% and was less than 10% for choline and creatine, which compare favorably with results from published studies. In vivo, the CV for GABA measurement was 26%, suggesting that 2D J-resolved MRS would be suitable for detecting physiological changes in GABA, similar to those reported using other methods.
我们在一台临床1.5-T磁共振成像扫描仪上，使用二维J分辨磁共振波谱（MRS）测定了γ-氨基丁酸（GABA）测量的可重复性。使用容积头部线圈和一个5英寸表面线圈，在体外对五种GABA浓度采集二维J分辨波谱。仅在5英寸表面线圈中记录了使用第六个极低浓度GABA模型和一名健康志愿者的额外波谱。在每种情况下，对3.01 ppm处的GABA共振进行定量；作为比较，记录胆碱（3.2 ppm）和肌酸（3.03 ppm）的峰积分。在生理浓度（1.2 mM）下，体外GABA测量在表面线圈中的可重复性显著高于容积线圈（P = 0.005），表面线圈的变异系数（CV）小于16%，而容积头部线圈高达68%。在使用其他波谱技术报告的体内GABA最小浓度（0.8 mM）下，且仅使用表面线圈检测到，GABA的CV为23%，胆碱和肌酸的CV小于10%，与已发表研究的结果相比具有优势。在体内，GABA测量的CV为26%，表明二维J分辨MRS适用于检测GABA中的生理变化，类似于使用其他方法报告的情况。
