MR imaging parameters and schedulea
Coil | Sequence | TE (ms) | TI (ms) | TR (ms) | Matrix | FOV (cm) | In-Plane Resolution (mm) | Thickness (mm) | Flip Angle | Bandwidth (Hz) | Time to Acquire (min:s) |
---|---|---|---|---|---|---|---|---|---|---|---|
8-Channel | Cisternography (FIESTA) | 3 | 6 | 320 × 320 | 18 | 0.56 × 0.56 | 1 | 55° | 163 | 4:27 | |
2D FLAIR | 122 | 2500 | 9454 | 320 × 320 | 18 | 0.56 × 0.56 | 2 | 90° | 122 | 4:06 | |
T1 spin-echob | 9 | 400 | 320 × 320 | 18 | 0.56 × 0.56 | 2 | 90° | 163 | 4:19 | ||
3-Inch surface | Cisternography (FIESTA) | 4 | 8 | 320 × 320 | 12 | 0.38 × 0.38 | 1 | 55° | 163 | 4:35 | |
2D FLAIR (3 pt) | 124 | 2000c | 10,000 | 320 × 320 | 12 | 0.38 × 0.38 | 2 | 90° | 122 | 4:12 | |
2D FLAIR (3 pt) | 123 | 2000 | 9000 | 320 × 320 | 12 | 0.38 × 0.38 | 2 | 90° | 122 | 4:24 | |
T1 spin-echob | 11 | 500 | 320 × 320 | 12 | 0.38 × 0.38 | 2 | 90° | 163 | 5:10 |
Note:—pt indicates patients.
↵a Protocol 1 (n = 3), 1 scan session: 20–28 hours post-IT contrast, includes pre- and post-IV contrast images. Protocol 2 (n = 2), 3 scan sessions: 1) pre- and post-IV contrast images (no IT), 2) 2 hours post-IT contrast/4 hours post-IV contrast, 3) 20–28 hours post-IT contrast/30 hours post-IV contrast. Protocol 2B (n = 1; scheduling conflict precluded pre-IT injection imaging as above in protocol 2 number 1), 2 scan sessions: 1) 20 hours post-IT contrast with pre-and post-IV contrast images, 2) 25 hours post-IT contrast/4 hours post-IV contrast.
↵b Parameters for T1 pre- and post-IV contrast scans did not change.
↵c FLAIR TI was varied from 1800 to 2800 ms for 2 patient scans, with all other parameters fixed.