TABLE 3.
Mean raw SNR, mean corrected SNR (CSNR: cm−3 min−1/2) and percent change compared with Wvoxel values for all techniques for NAA in NAWM in three volunteers.* CSNR values were calculated according to Equation 12 to account for differences in acquisition and repetition times and the effective spatial resolution
| 8-channel | ||||||||
|---|---|---|---|---|---|---|---|---|
| Cycle with residual water | Cycle without residual water | |||||||
| Methods | SNR | % | CSNR | Methods | SNR | % | CSNR | |
| Wvoxel | 17.2±1.9 | – | 9.9±1.1 | Wvoxel | 18.1±1.3 | – | 10.4±0.8 | |
| RWvoxel | 17.5±1.9 | +2% | 10.1±1.1 | NAAvoxel | 17.7±1.6 | −2% | 10.5±0.9 | |
| GLSRW | 16.0±1.7 | −7% | 9.3±1.0 | GLSNAA | 9.2±1.2 | −49% | 5.3±0.7 | |
| FPphasing | 17.5±1.9 | +2% | 10.1±1.1 | FPphasing | 17.±1.1 | −2% | 10.2±0.6 | |
| WSVD | 16.9±1.9 | −1% | 9.8 ±1.1 | WSVD | 17.3±1.5 | −5% | 9.9±0.9 | |
| RWcentral | 15.0±1.9 | −13% | 8.7±1.1 | NAAcentral | 15.9±1.4 | −12% | 9.2±0.8 | |
| 32-channel | ||||||||
| Wvoxel | 24.1±2 | – | 13.9±1.2 | Wvoxel | 25.3±2 | – | 14.6±1.2 | |
| RWvoxel | 24.5±2 | +2% | 14.1±1.3 | NAAvoxel | 24.8±2 | −2% | 14.3±1.4 | |
| GLSRW | 22.6±3 | −6% | 13.0±1.5 | GLSNAA | 14.2±4 | −44% | 8.2±2.6 | |
| FPphasing | 24.4±2 | +2% | 14.1±1.3 | FPphasing | 23.1±1 | −8% | 13.3±0.6 | |
| WSVD | 23.9±2 | −1% | 13.8±1.3 | WSVD | 24.4±2 | −3% | 14.1±1.0 | |
| RWcentral | 19.8±1 | −18% | 11.4±0.9 | NAAcentral | 20.6±2 | −19% | 11.9±1.1 | |
| +40% | +40% | |||||||
*
Standard deviation between the 3 volunteers is shown as mean ± SD. Data acquired using lactate-edited 3D MRSI sequence.