Protocol | MRI system | RF coil | TR (ms) | TE (ms) | TI (ms) | Voxel size (mm) | Flip angle |
---|---|---|---|---|---|---|---|
1 | Trio | Quadrature knee | 2500 | 4.38 | 1100 | 0.5 × 0.5 × 0.5 | 12 |
2 | TimTrio | Quadrature knee (Tim) | 2500 | 3.86 | 1100 | 0.5 × 0.5 × 0.5 | 12 |
3 | Trio | 8-Channel knee array | 2500 | 4.38 | 1100 | 0.5 × 0.5 × 0.5 | 12 |
4 | TrioTim | 15-Channel knee array | 2500 | 3.86 | 1100 | 0.5 × 0.5 × 0.5 | 12 |
RF, Radiofrequency. As indicated in the table, the ONPRC MRI system was upgraded throughout the study and different RF coils were used to enhance the signal-to-noise ratio. The parameters of MR image acquisition were adjusted accordingly.