Parameters of MPRAGE and PETRA
| Parameters | MPRAGE | PETRA | ||
|---|---|---|---|---|
| Small FOV | Middle FOV | Large FOV | ||
| FOV (mm) | 150 | 200 | 240 | 285 |
| Orientation | Axial | Axial | Axial | Sagittal |
| First TI (ms) | NA | NA | NA | 1000–1800 |
| TI (ms) | 800 | 800 | 800 | 700 |
| TR (ms) | 1570 | 1570 | 1570 | 3.75 |
| TE (ms) | 2.14 | 2.79 | 2.77 | 0.07 |
| Echo space (ms) | 5.2 | 5.2 | 5.2 | 3.75 |
| Flip angle (degrees) | 9 | 9 | 9 | 6 |
| Section thickness (ms) | 1.0 | 1.0 | 1.0 | 0.8 |
| Section oversampling (%) | 100 | 36.4 | 25.0 | 0 |
| Matrix | 154 × 192 | 168 × 192 | 224 × 256 | 352 × 352 |
| Radial spokes | NA | NA | NA | 35,000 |
| GRAPPA | 2 | 2 | 2 | NA |
| Resolution (mm) | 0.98 × 0.78 × 1.00 | 1.04 × 1.04 × 1.00 | 0.94 × 0.94 × 1.00 | 0.81 × 0.81 × 0.81 |
| Scan time (min/sec) | 3:27 | 3:05 | 3:05 | 4:20 |
Note:—NA indicates not available; GRAPPA, generalized autocalibrating partially parallel acquisition.