Table 1.
Scan parameters. All sequences were acquired at 3T. For each of the sequences, the main acquisition parameters are provided. The PD/−T2‐weighted and FLAIR sequences were used for semi‐automatic lesion segmentation. The DTI, MT and mcDESPOT sequences were used to obtain maps of the microstructural parameters fractional anisotropy (FA), radial diffusivity (RD), magnetisation transfer ratio (MTR), and myelin water fraction (MWF). FLAIR: fluid‐attenuated inversion recovery; FSPGR: fast spoiled gradient echo; SE: spin‐echo; IR: inversion recovery; EPI: echo‐planar imaging; EFGRE: enhanced fast gradient echo; SPGR: spoiled gradient recalled‐echo; bSSFP: balanced steady‐state free precession; IR‐SPGR: inversion recovery spoiled gradient; TE: echo time; TR: repetition time; TI: inversion time
| T1‐weighted | PD/T2‐weighted | FLAIR (T2‐weighted) | DTI | MT | mcDESPOT | |
|---|---|---|---|---|---|---|
| Pulse sequence(s) | FSPGR | SE | Se\IR | Se\epi | EFGRE | SPGR, bSSFP, IR‐SPGR |
| Native resolution (mm3) | 1.0 × 1.0 × 1.0 | 0.94 × 0.94 × 4.5 | 0.86 × 0.86 × 4.5 | 1.8 × 1.8 × 2.4 | 0.94 × 0.94 × 1.9 | 1.7 × 1.7 × 1.7 |
| Field of view (mm) | 256 | 240 | 220 | 230 | 240 | 220 |
| Matrix size | 256 × 256 × 172 | 256 × 256 | 256 × 256 | 96 × 96 × 36 | 128 × 128 × 100 | 128 × 128 × 88 |
| Slices | None ‐ 3D | 36 (3 mm + 1.5 mm gap) | 36 (3 mm + 1.5 mm gap) | 57 | None ‐ 3D | None ‐3D |
| Total acquisition time (min) | 7.5 | 2 | 3 | 12.5 | 4.5 | 10 |
| TE, TR (ms) | 3.0, 7.8 | 9.0/80.6, 3000 | 122.3, 9502 | 94.5, 16000 | 1.8, 26.7 | SPGR: 2.1, 4.7 bSSFP: 1.6, 3.2 IR‐SPGR: 2.1, 4.7 |
| TI (ms) | 450 | ‐ | 2,250 | ‐ | ‐ | IR‐SPGR: 450 |
| Off‐resonance pulse | 450°, 2 kHz off | |||||
| Flip angle (degrees) | 20 | 90 | 90 | 90 | 5 | SPGR: [3, 4, 5, 6, 7, 8, 9, 13, 18] bSSFP: [10.6, 14.1, 18.5, 23.8, 29.1, 35.3, 45, 60] IR‐SPGR: [5] |