Table 1 MRI protocol
From: Dynamic contrast-enhanced MR imaging in identifying active anal fistula after surgery
Parameters | T2WI | T1WI | T2WI | T2WI | T2WI | DCE-MRI | T1WI/Post |
Sequence type | 2D FSE | 2D FSE | 2D FSE | 2D FSE | 2D FSE | 3D FFE | 2D FSE |
Acquisition plane | Sagittal | Oblique axial | Oblique axial | Oblique axial | Oblique coronal | Oblique axial | Oblique axial |
Fat suppression | SPAIR | — | — | SPAIR | SPAIR | FS (Enhanced) | FS (Strong) |
TR/TE (ms/ms) | 4039/96 | 480/10 | 4789/80 | 6641/80 | 4039/96 | 3.7/1.3 | 630/10 |
Flip angle | 90/120 | 90/160 | 90/160 | 90/160 | 90/130 | 12 | 90/160 |
Bandwidth (Hz/pixel) | 195.3 | 244.1 | 244.1 | 244.1 | 195.3 | 488.2 | 244.1 |
Number of echo factor | 15 | 2 | 17 | 17 | 15 | — | 2 |
Slice thickness (mm) | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
Intersection gap (mm) | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0 | 0.4 |
Number of slices | 15 | 26 | 26 | 26 | 15 | 26 | 26 |
Acquisition matrix | 224 × 304 | 256 × 288 | 256 × 288 | 256 × 288 | 256 × 320 | 192 × 192 | 256 × 288 |
FOV (mm) | 290 × 250 | 250 × 200 | 250 × 200 | 250 × 200 | 220 × 250 | 250 × 200 | 250 × 200 |
Time (min: sec) | 1:25 | 2:04 | 1:21 | 1:53 | 1:49 | 3:46 (20 times) | 1:24 |