TABLE 1.
Scan Parameters for All MRI Sequences Utilized in This Study
| Sequence | 2D Ax PD FS |
2D Cor T1 |
2D Sag T2 FS |
2D Sag PD |
2D Cor PD FS |
3D Sag DESS FS |
|---|---|---|---|---|---|---|
| TE S + (msec) | 35 | 18 | 54 | 35 | 35 | 5.9 |
| TE S- (msec) | N/A | N/A | N/A | N/A | N/A | 31.3 |
| Flip angle (°) | 142 | 142 | 142 | 142 | 142 | 20 |
| Echo train length | 9 | 3 | 11 | 9 | 9 | 1 |
| NEX | 3 | 3 | 4 | 2 | 2 | 1 |
| Bandwidth (± kHz) | 50 | 50 | 50 | 50 | 50 | 41.7 |
| FOV (cm) | 14 | 14 | 14 | 14 | 14 | 16 |
| Matrix (RO × PE) | 512 × 224 | 416 × 224 | 384 × 192 | 384 × 224 | 384 × 224 | 416 × 512 |
| Resolution (mm2) | 0.27 × 0.63 | 0.34 × 0.63 | 0.36 × 0.72 | 0.36 × 0.63 | 0.36 × 0.63 | 0.34 × 0.27 |
| Slice thickness (mm) | 3 | 2.5 | 2.5 | 2.5 | 2.5 | 1.6 (0.8)a |
| Slice spacing (mm) | 0.3 | 0 | 0 | 0 | 0 | 0 |
| Number of slices | 36 | 44 | 40 | 40 | 44 | 80 (160)a |
| Parallel imaging | 2 × 1 | NA | 2 × 1 | NA | 2 × 1 | 2 × 1 |
| Scan time | 2:56 | 2:18 | 3:43 | 3:28 | 2:00 | 5:00 |
a
Note that slices were acquired at 1.6 mm slice thickness interpolated to 0.8 mm thicknesses. During review, slices in all orientations were viewed with 2.4 mm slice thickness. DESS utilized a slice direction spoiler gradient area of 31 mT1m−1ms1 (1.33 cycles of dephasing/mm). Ax, axial; Cor, coronal; Sag, sagittal; PD, proton density; FS, fat saturated; DESS, double echo in steady state; TR, repetition time; TE, echo time; NEX, number of averages; FOV, field of view; RO, readout; PE, phase encodes.