High- and low-SAR FSTIR sequence parameters for presurgical planning or postsurgical MR imaging assessment of DBS recipients with Parkinson diseasea
| Pulse Sequence | TR/TE/TI/Matrix/Scan Time (min) | Section Thickness/FOV/No. of Avg/No. of Sections | Echo-Train/BW (kHz) | Refocusing Pulse Width (Default Value)/Refocusing Pulse Flip Angles in FSTIR | Whole-Head SAR (W/kg) (Estimated) |
|---|---|---|---|---|---|
| High-SAR 2D Ax FSTIR (PD+T1w)b | 4s/12 ms/140 ms/256 × 192/5:30 | 3 mm/24 cm/2/30 | 8/ ± 15.8 | 1.6 ms (1.6 ms)/1800 | 1.5 |
| Low-SAR 2D Ax FSTIR (PD+T1w)b | 10–13 s/11–13 ms/130 ms/256 × 192/7:10–8:30 | 3 mm/24 cm/1/24–32 (Interleave) | 10/ ± 15.8 | 2.6 ms (1.6)/first = 1100, second = 1000, rest of the refocusing angles = 1100 | ≤0.1 |
Note:—BW indicates bandwidth; T1w, T1-weighted; Avg, average; Ax, axial.
↵a Magnet strength, 1.5T; RF coil: transmit-receive 1-channel head coil.
↵b Short Tau FSTIR produces T1-weighted for short T1 tissues (fat, white matter darker, close to null) and proton density (PD) weighting for long T1 tissues (CSF, gray matter brighter, far away from null).