Table 2:

MR imaging parameters and schedulea

CoilSequenceTE (ms)TI (ms)TR (ms)MatrixFOV (cm)In-Plane Resolution (mm)Thickness (mm)Flip AngleBandwidth (Hz)Time to Acquire (min:s)
8-ChannelCisternography (FIESTA)36320 × 320180.56 × 0.56155°1634:27
2D FLAIR12225009454320 × 320180.56 × 0.56290°1224:06
T1 spin-echob9400320 × 320180.56 × 0.56290°1634:19
3-Inch surfaceCisternography (FIESTA)48320 × 320120.38 × 0.38155°1634:35
2D FLAIR (3 pt)1242000c10,000320 × 320120.38 × 0.38290°1224:12
2D FLAIR (3 pt)12320009000320 × 320120.38 × 0.38290°1224:24
T1 spin-echob11500320 × 320120.38 × 0.38290°1635:10
  • 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.