Assessment of GABA concentration in human brain using two-dimensional proton magnetic resonance spectroscopy

A quantitative method to assess in vivo brain gamma-aminobutyric acid (GABA ) levels is proposed using a J-resolved, two-dimensional (2D) magnetic reso nance spectroscopy (MRS) technique. Localized, J-resolved 2D MR spectra wer e obtained from a 12-cm(3) voxel in the occipital lobe of 36 healthy volunt eers (18 male and 18 female, age: 25.1 +/- 4.8 years). Based on phantom mea surements, a GABA resonance peak located at 2.94 ppm, 7.45 Hz, in J-resolve d 2D MRS overlaps the least with other resonance peaks which arise from N-a cetylaspartate, choline, creatine, glutamate and glutamine. Measurements of this resonance peak yield in vivo GABA concentrations of 1.01 +/- 0.36 mu mol/cm(3) for male and 1.16 +/- 0.43 mu mol/cm(3) for female volunteers, wi thout correction for T1 and T2 relaxation effects. These results are in goo d agreement with previously reported data and suggest that, with further de velopment, 2D MRS may provide a practical means to estimate the concentrati on of this important neurotransmitter. (C) 2000 Elsevier Science Ireland Lt d. All rights reserved.