Table 1.
MRI acquisition parameters.
| Site | Scanner and scan | Resolution | Voxel size | TR | TE | TI |
|---|---|---|---|---|---|---|
| Site 1 | Philips Intera 3T | |||||
| 3D T1 weighted | 320 × 320 × 200 | 0.8 × 0.8 × 0.8 | 6.2 | 3.0 | ||
| 3D T2 weighted | 320 × 320 × 200 | 0.8 × 0.8 × 0.8 | 2500 | 363 | ||
| FLAIR | 320 × 320 × 200 | 0.8 × 0.8 × 0.8 | 8000 | 337 | 2400 | |
| Site 2 | Siemens Verio 3T | |||||
| 3D T1 weighted | 320 × 320 × 176 | 0.78 × 0.78 × 0.78 | 1900 | 3.4 | 900 | |
| 3D T2 weighted | 512 × 512 × 160 | 0.488 × 0.488 × 1.0 | 3200 | 409 | ||
| FLAIR | 320 × 320 × 160 | 0.83 × 0.83 × 0.83 | 8000 | 337 | 2400 | |
| Site 3 | Philips Achieva 3T | |||||
| 3D T1 weighted | 320 × 320 × 200 | 0.8 × 0.8 × 0.8 | 6.2 | 3.0 | ||
| 3D T2 weighted | 320 × 320 × 200 | 0.8 × 0.8 × 0.8 | 2500 | 363 | ||
| FLAIR | 320 × 320 × 200 | 0.8 × 0.8 × 0.8 | 8000 | 337 | 2400 | |
| Site 4 | Philips Achieva 3T | |||||
| 3D T1 weighted | 320 × 320 × 112 | 0.8 × 0.8 × 1.6 | 6.5 | 3.2 | ||
| 3D T2 weighted | 320 × 320 × 112 | 0.8 × 0.8 × 1.6 | 2500 | 255 | ||
| FLAIR | 336 × 336 × 112 | 0.76 × 0.76 × 1.6 | 4800 | 330 | 1650 | |
| Controls: Site1 | Philips 3T Achieva | |||||
| 3D T1 weighted | 256 × 250 × 165 | 1.0 × 1.0 × 1.0 | 8.1 | 3.5 | ||
| Controls: OASIS | (Siemens TIM Trio 3T) | |||||
| 3D T1 weighted | 256 × 256 × 176 | 1.0 × 1.0 × 1.0 | 2400 | 3.16 | ||
3 T = 3 Tesla; 3D = 3-dimensional, TR = repetition time; TE = echo time; TI = inversion time; FLAIR = Fluid Attenuated Inversion Recovery; Site 1 control scans were acquired with parallel imaging, SENSE factor 1.5.