Table 2 MR imaging parameters
| Â | Heavily T2W 3D FLAIR (PPI) | Heavily T2W 3D IR (PEI) | MR cisternography (MRC) | T2W imaging |
|---|---|---|---|---|
TR/TE (ms) | 9000/542 | 9000/542 | 4400/542 | 1300/123 |
Inversion time (ms) | 2250 | 2050 |  −  |  −  |
Frequency-selective fat suppression prepulse |  +  |  +  |  +  |  −  |
Flip angle | Average flip angle 120° followed by 90° restore pulse | Average flip angle 120° followed by 90° restore pulse | Average flip angle 120° followed by 90° restore pulse | Average flip angle 120° followed by 90° restore pulse |
Echo train length | 519 | 519 | 519 | 87 |
Acquisition matrix size | 324 × 384 | 324 × 384 | 324 × 384 | 320 × 320 |
FOV (mm2) | 166 × 196 | 166 × 196 | 166 × 196 | 200 × 200 |
Axial slices | 104 | 104 | 104 | 160 |
In-plane resolution (mm) | 0.5 × 0.5 | 0.5 × 0.5 | 0.5 × 0.5 | 0.3 × 0.3 (after zero-fill interpolation) |
Slice thickness (mm) | 1.0 | 1.0 | 1.0 | 0.3 |
Bandwidth (Hz/pixel) | 434 | 434 | 434 | 446 |
Acceleration factor | 2 using GRAPPA (in-plane right-left phase-encoding direction) | 2 using GRAPPA (in-plane right-left phase-encoding direction) | 2 using GRAPPA (in-plane right-left phase-encoding direction) | 2 using GRAPPA (in-plane right-left phase-encoding direction) |
Number of excitations | 2 | 2 | 1.8 | 2 |
Phase partial Fourier acquisition |  +  |  +  |  +  |  +  |
Slice partial Fourier acquisition |  −  |  −  |  −  |  +  |
Total time (min.sec) | 7.17 | 7.17 | 3.15 | 6.27 |