Table 1. Recommended MRI protocol.
| Parameters | MRI characteristics | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Axial fat-suppressed TSE intermediate-weighted image | Axial TSE T1-weighted image | Sagittal fat-suppressed TSE intermediate-weighted image | Sagittal TRUFI-cine T2-weighted image* | ||||||||
| 1.5 T | 3 T | 1.5 T | 3 T | 1.5 T | 3 T | 1.5 T | 3 T | ||||
| Echo time (ms) | 37 | 34 | 9.6 | 9.8 | 39 | 32 | 1.79 | 3.74 | |||
| Slices (number) | 84 | 80 | 84 | 80 | 32 | 25 | 1 (20 acquisitions) | 1 (20 acquisitions) | |||
| Section thickness (mm) | 3 | 3 | 3 | 3 | 3 | 3 | 10 | 10 | |||
| Interslice distance (mm) | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 2.0 | 2.0 | |||
| Field-of-view (cm) | 20×20 | 20×20 | 20×20 | 20×20 | 18×18 | 18×18 | 20×20 | 20×20 | |||
| Repetition time (ms) | 3,850 | 8,770 | 758 | 1,900 | 3,520 | 3,000 | 4.3 | 7.47 | |||
| Flip angle (degrees) | 110 | 138 | 110 | 127 | 180 | 134 | 56 | 30 | |||
| Acquisition matrix | 256×320 | 256×320 | 302×336 | 256×320 | 285×320 | 269×384 | 290×320 | 290×320 | |||
| Bandwidth (Hertz/pixel) | 180 | 180 | 156 | 221 | 135 | 220 | 504 | 300 | |||
| Acceleration factor (R) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | |||
| Scan time (min:s) | 3:08 | 9:58 | 3:12 | 9:13 | 2:22 | 3:08 | 35 s | 58 s | |||
*, dynamic acquisition (foot dorsi-flexion); slices were acquired sequentially. MRI, magnetic resonance imaging; TSE, turbo spin-echo; TRUFI, true fast imaging with steady-state free precession; ms, milliseconds; mm, millimeters; cm, centimeters.