Table 1.
Sequence parameters
| T2W | DWI | 31P MRSIb | 1H MRSI | |
|---|---|---|---|---|
| Sequence type | Turbo‐Spin‐Echo | EPI (RESOLVE); b0, b100, b400, and b800 | 3D MRSI with non‐selective BIR‐4 excitation | PRESS‐like with spectrally and spatially selective RF refocusing pulses |
| FOV | 111 × 111 mm2 | 154 × 154 mm2 |
a): 120 × 100 × 100 mm3 b): 120 × 120 × 120 mm3 |
84 × 70 × 70 mm3 |
| Matrix | 256 × 256 | 88 × 88 |
a): 12 × 10 × 10 b): 10 × 10 × 10 |
12 × 10 × 10 |
| Voxel sizea | 0.43 × 0.43 × 3 mm3 | 1.75 × 1.75 × 3 mm3 |
a): 4.9 cc b): 9.1 cc |
1.4 cc |
| Slices | 19 | 19 | n.a. | n.a. |
| Slice thickness | 3 | 3 | n.a. | n.a. |
| TR (ms) | 4250 | 4400 | 1500 | 1000 |
| TE (ms) | 84 | 68 | n.a. | 135 |
| Bandwidth (Hz) | 106 (per pixel) | 1015 | 10000 (spectral) | 2400 (spectral) |
| Vector size | n.a. | n.a. | 2048 | 1024 |
| Averages | 1 | 1 | 4 (weighted) | 1 |
| Acquisition time (min:sec) | 1:59 | 4:34 | 13:09 | 7:01 |
| Flip angle (⁰) | n.a. | n.a. | 45 | n.a. |
| Filter | Prescan normalization filter | n.a. | 100% Hamming filter | 50% Hamming filter |
DWI, diffusion‐weighted imaging; MRSI, magnetic resonance spectroscopic imaging.
a
For the MRSI measurements, this was based on the true voxel size based on voxel volume within the 50% range of the maximum of the point spread function after correcting for spatial filter and sampling scheme.
b
Two different measurement parameter sets were used: set a) and set b).