“Core” and “preferred” imaging protocols for diffusion-weighted imaging
| Parameter | “Core” | “Preferred” No. 1 (High Angular Resolution) | “Preferred” No. 2 (More b-Values) |
|---|---|---|---|
| Orientation | Axial | Axial | Axial |
| Coil | Any | Phased array ≥8 channels | Phased array ≥8 channels |
| Readout | EPI | EPI | EPI |
| TR (ms) | ∼9000 | ∼9000 | ∼9000 |
| TE (ms) | Min | Min (<100) | Min (<100) |
| FOV (mm2) | 256 × 256 or 350 (66% phase) | 256 × 256 or 350 (66% phase) | 256 × 256 or 350 (66% phase) |
| Matrix size | 128 × 128 | 128 × 128 | 128 × 128 |
| Sections/thickness (mm) | Any/≤3 | 59/2.7 | 59/2.7 |
| Section gap (mm) | 0 | 0 | 0 |
| Voxel size (mm) | ≤3 in all dimensions | Isotropic 2.73 | Isotropic 2.73 |
| Directions | ≥12 | 64 | ≥12 |
| Dual-echo | Any | No | No |
| Fat-suppression | Any | Yes | Yes |
| Phase-encode direction | A to P | A to P | A to P |
| BW (Hz/pixel) | 1346 | 1346 | 1346 |
| Parallel imaging factor | Any | 2 | 2 |
| b-value (s/mm2) | 2 (0, ∼1000) | 2 (0, 1300) | ≥3 (eg, 0, ∼1000, ∼2000) |
| No. b=0 images | 1 | 1 per 8 directions if allowed | 1 per 8 directions if allowed |
Note:—Min indicates minimum; A to P, anterior to posterior; BW, bandwidth.