Table 1.
The concentration estimates (mM) and CRLBs (%) of GABA, Glu and tCr are tabulated for the 6 brain regions studied, together with the voxel size, number of signal averages (NSA), and mean fractional GM content (fGM), GM/(GM+WM). The metabolite concentration was estimated with reference to the mean tCr of the medial occipital region at 8 mM, following normalization of metabolite signal estimates to the GM+WM water signal. Data are mean ± SD (n = 6 for medial occipital and left parietal, and n = 3 for other brain regions). Asterisks (*) represent the significance of the metabolite level difference from the estimates in the medial occipital region (* p ≤ 0.05 and **p ≤ 0.001).
| Brain region | Voxel size | NSA | fGM | Concentration (mM) (CRLB %) | ||
|---|---|---|---|---|---|---|
| GABA | Glu | tCr | ||||
| Medial Occipital (MO) | 23×23×23 mm3 (12.2 mL) | 128 | 0.73±0.02 | 0.80±0.06 (8.8±0.8) | 9.20±0.60 (3.2±0.4) | 8 (±0.57) (1±0) |
| Left Parietal (LP) | 35×23×15 mm3 (12.1 mL) | 128 | 0.14±0.02 | 0.51±0.07** (11.7±2.0) | 6.44±0.44** (3.8±0.4) | 6.05±0.43** (1±0) |
| Medial Frontal (MF) | 18×23×28 mm3 (11.6 mL) | 128 | 0.70±0.02 | 0.87±0.06 (9.7±0.6) | 10.30±0.90 (3.0±0.0) | 8.30±0.66 (1±0) |
| Posterior Cingulate (PC) | 26×18×15 mm3 (7.0 mL) | 320 | 0.57±0.04 | 0.66±0.04** (12.0±1.5) | 10.12±0.74 (3.0±0.0) | 7.81±0.66 (1±0) |
| Left Hippocampus (LH) | 30×13×10 mm3 (3.9 mL) | 512 | 0.70±0.03 | 1.08±0.08** (10.7±2.1) | 9.15±0.81 (4.7±1.2) | 8.08±0.48 (1±0) |
| Left Frontal (LF) | 32×18×20 mm3 (11.5 mL) | 128 | 0.24±0.03 | 0.46±0.03** (12.3±1.5) | 7.19±0.55** (3.3±0.6) | 6.28±0.02** (1±0) |