Table 1.
Imaging parameters for the slow protocol involving 2D UTE single-echo acquisition, 2D IR-UTE single-echo acquisition, 3D UTE single-echo acquisition and 3D IR-UTE single-echo acquisition, and the fast protocol involving 3D dual-echo UTE acquisition and 3D IR-UTE single-echo acquisition with reduced number of TEs (5 radial spokes were acquired per IR preparation in each 3D IR-UTE acquisition).
| Sequences | TR (ms) |
TE (ms) |
TI (ms) |
FOV (cm) |
Acquisition Matrix |
#spokes | #slice | Thickness (mm) |
BW (kHz) |
Flip Angle |
Scan time (min) |
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Slow Protocol |
2D UTE Single-Echo |
100 | 0.008; 0.1; 0.2; 0.3; 0.4; 0.6; 0.8; 1; 1.2; 1.6; 2; 3; 4; 6; 8; 10 |
- | 15 | 192 × 192 | 191 | 1 | - | 250 | 10° | 0.32 |
| 2D IR-UTE Single-Echo |
100 | 0.008; 0.1; 0.2; 0.3; 0.4; 0.6; 0.8; 1; 1.2; 1.6; 2; 3; 4; 6; 8; 10 |
45 | 15 | 128 × 128 | 191 | 1 | - | 250 | 10° | 0.32 | |
| 3D UTE Single-Echo |
14.5 | 0.008; 0.1; 0.2; 0.3; 0.4; 0.6; 0.8; 1; 1.2; 1.6; 2; 3; 4; 6; 8; 10 |
- | 15 | 192 × 192 | 7449 | 10 | 7 | 250 | 10° | 1.8 | |
| 3D IR-UTE Single-Echo |
100 | 0.03; 0.1; 0.2; 0.3; 0.4; 0.6; 0.8; 1; 1.2; 1.6; 2; 3; 4; 6; 8; 10 |
45 | 15 | 128 × 128 | 6131 | 10 | 7 | 250 | 10° | 2.0 | |
| Fast Protocol |
3D UTE Dual-Echo |
14.5 | 0.03/2.2; 0.2/4.4; 0.4/6.6; 0.6/8.8; 0.8/11 |
- | 15 | 192 × 192 | 7449 | 10 | 10 | 250 | 10° | 1.8 |
| 3D IR-UTE Single-Echo |
100 | 0.03; 0.2; 0.4; 0.6; 0.8; 2.2; 4.4; 6.6; 8.8; 11.0 |
45 | 15 | 128 × 128 | 6131 | 10 | 10 | 250 | 10° | 2.0 | |