Table 2. Sequence parameters typically used at the author’s institutions.
Typical sequence parameters used. Settings and sequence names are vendor specific and can vary.
| T2w coronal | 3D T2wMRCP | Axial T2w | Dynamic phases & standard delayed phases |
Hepatobiliary phase high-resolution |
|
|---|---|---|---|---|---|
| Sequence | SSFSE / HASTE / single- shot TSE / FSE |
RARE-based 3D fat-sat |
FSE fat sat | GRE or volume interpolated 3D SPGR (VIBE / LAVA / THRIVE / TIGRE) with spectral-spatial fat-sat |
GRE 3D SPGR spectral-spatial fat-sat |
| Orientation | coronal | coronal | axial | axial | axial |
| Purpose | check for cholestasis, if present, perform MRCP |
cholangiogram | T2w images | dynamic phase imaging dur: fluoroscopic trigger portal venous: ~50sec after arterial peak venous: ~2min after arterial peak |
near-isotropic scan to visualize biliary system at contrast agent-specific delay |
|
| |||||
| TR/TE | 1000/90 | 3750/590 (120) |
15000/94 (ETL 16) |
4/1.9 | 5.4/2.1 |
| FOVx/FOVy | 512 × 512 | 512 × 512 | 512 × 512 (75%) |
512 × 512 (75%) |
400 × 320 |
| Acq Matrix | 352 × 256 | 288 × 288 | 324 × 224 | 256 × 192 | 228 × 224 |
| FA | 90 | 90 | 90 | 12-15 | variable 40-45 gadoxetic acid 25-30 gadobenate dimeglumine |
| Number of signal averages | 0.53 | 1 | 2 | 1 | 1 |
| Slice thickness | 6 | 1.4 | 5 | 5 | 2 |
|
No. of slices
(requirements) |
24 a) as much as possible in a 20-24s breath hold b) cover the entire liver |
112 a) anatomically adapted to cover the biliary tree |
58 a) anatomically adapted to cover the entire liver |
16 a) as much as possible in a 20-24s breath hold b) cover the entire liver |
192 a) as much as possible in a 20-24s breath hold (alternative: navigator- gating) b) cover the entire liver |
| Interslice gap | none | 0.7 | 15% | none | none |
| Receiver bandwidth | ±50kHz | ±50kHz | ±50kHz | ±62.5kHz | ±62.5kHz |
| Applied coil | 8ch phased array | 8ch phased array | 8ch phased array | 8ch phased array | 32ch body phased array |
| True resolution [mm3] | 1.5 × 2.0 × 6.0 | 1.8 × 1.8 × 1.4 | 1.6 × 2.3 × 5.0 | 2.0 × 2.7 × 5.0 | 1.39 × 1.8 × 2.0 |
| Interpolated res. [mm3] | 1.0 × 1.4 × 2.5 | 0.8 × 0.8 × 1.0 | |||
| Breathing | breath hold | respiratory triggered | respiratory triggered | breath hold | breath hold |
| Acceleration techniques | Data-driven or image- based parallel imaging |
Data-driven or image-based parallel imaging |
Data-driven or image-based parallel imaging |
||