Default Acquisition and Processing Parameters Used in This Study
| Parameter | Discovery RX | Discovery LS | Advance | HRRT |
|---|---|---|---|---|
| Attenuation correction | 64-slice CT | 4-slice CT | 68Ge pin | 137Cs point |
| Scatter correction | Bergstrom (2D), single-scatter simulation (3D) | Bergstrom (2D), single-scatter simulation (3D) | Bergstrom (2D), single-scatter simulation (3D) | Single-scatter simulation |
| Randoms correction | Singles | Delayed events | Delayed events | Singles |
| Reconstruction algorithm | OSEM (2D), 3D OSEM (3D) | OSEM (2D), 3DRP (3D) | OSEM (2D), 3DRP (3D) | 3D OSEM |
| Reconstruction parameters | 2 iterations and 21 subsets (2D), 2 iterations and 21 subsets (3D) | 2 iterations and 21 subsets (2D); transaxial ramp, 4.0 mm (3D) | 2 iterations and 21 subsets (2D); transaxial ramp, 4.0 mm (3D) | 6 iterations and 16 subsets |
| Axial filter | Standard (2D), standard (3D) | Yes (2D); axial ramp, 8.5 mm (3D) | Yes (2D); axial ramp, 8.5 mm (3D) | None |
| Postprocessing filter (mm) | 5 (2D), 5 (3D) | 5 (2D), None (3D) | 5 (2D), None (3D) | 2 |
| Pixel size (mm) | 1 | 1 | 1 | 1.22 |
| Slice thickness (mm) | 3.27 | 4.25 | 4.25 | 1.22 |
OSEM denotes reconstruction algorithm discussed in the study by Hudson and Larkin (8), and 3DRP denotes analytic reprojection reconstruction algorithm discussed in the study by Kinahan and Rogers (9). Relevant acquisition mode is indicated in parentheses.