Table 1.
Acquisition Parameters for tDWI and dDWI Pulse Sequences in Diffusion Phantom and In Vivo
| Phantom | In Vivo (Abdomen) | In Vivo (Pelvis) | ||||
|---|---|---|---|---|---|---|
| tDWI | dDWI | tDWI | dDWI | tDWI | dDWI | |
| Orientation | Coronal | Coronal | Axial | Axial | Axial oblique | Axial oblique |
| Diffusion scheme | Monopolar | Monopolar | Monopolar | Monopolar | Monopolar | Monopolar |
| Gradient directions [x,y,z] | [1.0, 1.0, −0.5], [1.0, −0.5, 1.0], [−0.5, 1.0, 1.0] | [1.0, 1.0, 1.0] | [1.0, 1.0, −0.5], [1.0, −0.5, 1.0], [−0.5, 1.0, 1.0] | [1.0 1.0 1.0] | [1.0, 1.0, −0.5], [1.0, −0.5, 1.0], [−0.5, 1.0, 1.0] | [1.0, 1.0, 1.0] |
| Read-out | SS SE-EPI | SS SE-EPI | SS SE-EPI | SS SE-EPI | SS SE-EPI | SS SE-EPI |
| b Values (s/mm2) | 0, 500, 900, 2000 | 0, 500, 900, 2000 | 50, 400, 800 | 50, 400, 800 | 50, 1000, 1600 | 50, 1000, 1600 |
| Averages | 4, 4, 4, 4 | 4, 12, 12, 12 | 1, 2, 4 | 3, 6, 12 | 1, 5, 10 | 3, 15, 30 |
| TE (ms) | 110 (1.5 T); 99 (3.0 T) | 106 (1.5 T); 95 (3.0 T) | 73 (1.5 T); 70 (3.0 T) | 70 (1.5 T); 68 (3.0 T) | 83 (1.5 T); 71 (3.0 T) | 79 (1.5 T); 69 (3.0 T) |
| TR (ms) | 10 000 | 10 000 | 5000 | 5000 | 5000 | 5000 |
| Slice thickness (mm) | 5 | 5 | 5 | 5 | 5 | 5 |
| Number of slices | 5 | 5 | 30 | 30 | 20 | 20 |
| Matrix | 128 × 128 | 128 × 128 | 128 × 128 | 128 × 128 | 114 × 114 | 114 × 114 |
| FOV (mm2) | 210 × 210 | 210 × 210 | 370 × 250 | 370 × 250 | 250 × 250 | 250 × 250 |
| GRAPPA acceleration | 2 | 2 | 2 | 2 | 2 | 2 |
| Fat suppression | None | None | SPAIR | SPAIR | SPAIR | SPAIR |
| Acquisition time (min) | 7:10 | 7:10 | 2:12 | 2:12 | 4:27 | 4:27 |
The in vivo acquisitions were performed during free breathing.
Abbreviations: dDWI, diagonal diffusion-weighted imaging; FOV, field of view; GRAPPA, generalized autocalibrating partial parallel acquisition; SPAIR, spectral attenuated inversion recovery; tDWI, 3-scan trace diffusion-weighted imaging; SS SE-EPI, single-shot spin-echo echo planar imaging; TE, echo time; TR, repetition time.