Table 2.
Exemplar image acquisition parameters for a standard clinical neurovascular structural protocol and possible rodent counterparts at co-authors’ sites
| Sequences | Purpose | Typical clinical parameters (3 T) | Typical preclinical parameters for rats (7 and 9.4 T) | Typical preclinical parameters for mice (7 and 9.4 T) |
|---|---|---|---|---|
| T1w | Detailed anatomy | 3D, voxel size: 1 mm isotropic, TR/TE = 2500/4.37 ms, TI = 1100 ms, ~ 4 min | 2D, voxel size: 0.20 × 0.20 × 0.8 mm, TR/TE 780/9.5 ms, ~ 5 min | 2D, voxel size: 0.07 × 0.07 × 0.4 mm, TR/TE = 700/11 ms, ~ 10 min |
| T2w | Lacunes, PVS | 3D, voxel size: 0.9 mm isotropic, TR/TE = 3200/408 ms, ~ 4 min | 2D, voxel size: 0.1 × 0.07 × 0.3 mm, TR/TE = 4000/26 ms, ~ 9 min | 2D, voxel size: 0.07 × 0.07 × 0.4 mm, TR/TE = 5000/45 ms, ~ 9 min |
| FLAIR | WMH, juxtacortical or ventricular lesions | 3D, voxel size: 1 mm isotropic, TR/TE = 5000/388 ms TI = 1800 ms, ~ 6 min | 2D, voxel size: 0.34 × 0.34 × 1.0 mm, TR/TE 8000/30 ms, TI 1930 ms, ~ 10 min | 2D, voxel size: 0.13 × 0.13 × 0.5 mm, TR/TE = 6000/15 ms, TI = 1700 ms, ~ 12 min |
| T2*w/GRE or SWI | Microbleeds, prior ICH, cortical siderosis, tissue mineral deposition; separate intracranial contents from skull | 2D, voxel size: 0.6 × 0.6 × 3 mm, TR/TE = 28/20 ms, flip angle = 9°, ~ 4 min (SWI) | 3D, voxel size: 0.08 × 0.08 × 0.03 mm, TR/TE = 32/15 ms, flip angle = 12°, ~ 10 min (GRE) | 2D, voxel size: 0.06 × 0.06 × 0.5 mm, TR/TE = 415/5 ms, flip angle = 12°, ~ 10 min (GRE) |
| DWI/DTI | Acute ischaemic lesions; fractional anisotropy (FA), mean diffusivity, tract integrity, tractography | 2D, voxel size: 1.3 × 1.3 × 3 mm, TR/TE = 4000/75 ms, 30 directions, ~ 6 min | 2D, voxel size: 0.17 × 0.17 × 0.7 mm, TR/TE = 5000/20 ms, 30 directions, ~ 20 min | 2D, voxel size: 0.15 × 0.23 × 0.5 mm TR/TE = 3000/32 ms, 30 directions, ~ 10 min |
| PD | Separate intracranial contents from skull to measure ICV; a few centres use for lesion differentiation (not used in STRIVE) | 3D, voxel size: 1 × 1 × 1 mm, TR/TE = 6.04/2.44 ms, ~ 2 min | 2D, voxel size: 0.1 × 0.07 × 0.3 mm, TR/TE = 4000/4 ms, ~ 9 min | 2D, voxel size: 0.07 × 0.07 × 0.4 mm, TR/TE = 5000/8 ms, ~ 9 min |
Times refer to total sequence acquisition time. TR repetition time, TE echo time, TI inversion time