Table 1.
Pulse sequence parameters
| Sequence name | Type | Repetition time (ms) | Echo time (ms) | Inversion time (ms) | Flip angle (degree) | Section thickness/gap (mm) | Pixel size (mm) | Number of slices | Echo train length | Field of view (mm) | Matrix size | Number of excitations | Scan time (min) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MR cisternography (MRC) | SPACE with restore pulse | 4400 | 544 | NA | 90/ initial 180 decrease to constant 120 | 1/0 | 0.5 × 0.5 | 104 | 173 | 165 × 196 | 332 × 384 | 1.8 | 3 |
| 3D-real IR | SPACE with inversion pulse | 16000 | 661 | 2700 | 90/ constant180 | 1/0 | 0.5 × 0.5 | 104 | 173 | 165 × 196 | 332 × 384 | 2 | 10 |
| Heavily T2 weighted 3D-FLAIR (PPI) and PEI | SPACE with inversion pulse | 16000 | 544 | 2900 (2500 for PEI) | 90/ constant 180 | 1/0 | 0.5 × 0.5 | 104 | 173 | 165 × 196 | 332 × 384 | 1.4 | 7 for PPI, 7 for PEI |
GeneRalized Autocalibrating Partial Parallel Acquisition (GRAPPA) × 2 for all sequences. All sequences utilize a frequency selective fat suppression pre-pulse. Each 3D slab is set in an identical axial orientation. 3D-real IR, 3D inversion recovery with phase sensitive reconstruction (real reconstruction). PPI, positive perilymph image; PEI, positive endolymph image; SPACE, sampling perfection with application-optimized contrasts using different flip angle evolutions.