Table 2. Cramér-Rao lower bounds (%): median (25–75 percentile).
| Metabolites | [1] sLASER×32 | [2] sLASER×48 | [3] sSTEAM4×32 | [4] sSTEAM4×48 | [5] sSTEAM4×64 | [6] sSTEAM8×32 |
|---|---|---|---|---|---|---|
| Aspartate | 14.52,3,5,6 (13.0–18.5) | 13.01,3,4,5,6 (12.0–15.5) | 19.01,2 (16.5–21.0) | 17.02 (15.5–19.0) | 17.01,2 (15.0–19.0) | 17.51,2 (16.0–20.0) |
| GABA | 18.53,4,5,6 (16.0–20.5) | 18.03,4,5,6 (15.0–20.0) | 10.01,2,4,5,6 (10.0–11.0) | 9.01,2,3,5,6 (8.0–11.0) | 9.01,2,3,4,6 (8.0–10.5) | 10.01,2,3,4,5 (9.0–11.0) |
| Glutamine | 10.03,4,5,6 (9.5–12.0) | 10.03,4,5,6 (9.0–11.0) | 7.01,2,4,5,6 (7.0–8.0) | 6.01,2,3,5,6 (5.0–7.0) | 6.01,2,3,4,6 (5.0–7.0) | 7.01,2,3,4,5 (7.0–8.0) |
| Glutamate | 3.02,3,4,5,6 (2.5–3.0) | 2.51,3,4,5,6 (2.0–3.0) | 2.01,2 (2.0–2.0) | 2.01,2 (2.0–2.0) | 2.01,2 (2.0–2.0) | 2.01,2 (2.0–3.0) |
| Glutathione | 6.52,4,5,6 (6.0–8.5) | 6.01,4,5 (5.5–7.0) | 6.04,5 (6.0–7.0) | 6.01,2,3,6 (5.0–6.0) | 5.01,2,3,6 (5.0–6.0) | 6.01,4,5 (5.5–7.0) |
| Myo-inositol | 4.02,3,4,5,6 (4.0–5.0) | 4.01,3,4,5,6 (3.0–4.0) | 3.01,2,5 (3.0–4.0) | 3.01,2 (3.0–4.0) | 3.01,2,3,6 (3.0–3.0) | 3.01,2,5 (3.0–4.0) |
| Taurine | 12.05,6 (10.0–15.0) | 12.03 (11.0–14.0) | 13.02,5,6 (10.5–16.0) | 12.05 (10.5–14.0) | 11.01,3,4 (9.0–13.0) | 11.01,3 (9.0–13.5) |
| tCho | 3.02,3,4,5,6 (3.0–4.0) | 3.01,3,4,5,6 (3.0–4.0) | 3.01,2,4,5 (2.0–3.0) | 2.01,2,3,6 (2.0–3.0) | 2.01,2,3,6 (2.0–3.0) | 3.01,2,4,5 (2.0–3.0) |
| tCr | 1.03,4,5,6 (1.0–1.0) | 1.03,4,5,6 (1.0–1.0) | 2.01,2 (2.0–2.0) | 2.01,2 (2.0–2.0) | 2.01,2 (2.0–2.0) | 2.01,2 (2.0–2.0) |
| tNAA | 1.53,4,5,6 (1.0–2.0) | 1.03,4,5,6 (1.0–2.0) | 3.01,2,4,5,6 (2.0–3.0) | 2.01,2,3 (2.0–2.5) | 2.01,2,3 (2.0–2.0) | 2.01,2,3 (2.0–3.0) |
The values were not normally distributed in all metabolites, and median values are presented. Statistically significant difference (P<0.05) between different scan conditions are indicated with supersets of the numbers. sLASER = semi-LASER (TR =6.5 s); sSTEAM4/8 = short-TE STEAM (TR = 4/8 s); ×32, ×48 and ×64 = 32, 48 and 64 averages, respectively. sLASER, semi-localized by adiabatic selective refocusing; sSTEAM, short echo time stimulated echo acquisition mode; TR, time of repetition; GABA, γ-aminobutyric acid; tCho, total choline; tCr, total creatine; tNAA, total N-acetylaspartate.