Table 1.
Parameters for MDCT data acquisition and image reconstruction.
| MDCT system | Reference MDCT scan | Follow-up MDCT scan | |
|---|---|---|---|
| LightSpeed VCT | Revolution CT | ||
| Radiation dose level | Regular | Regular | Reduced* |
| Data acquisition | |||
| Tube potential (kVp) | 120 | 120 | 120 |
| Tube current (mA) | 400 | 400 | 90 |
| Automatic exposure control (noise index) | Combined xyz-axis (25) | Combined xyz-axis (12.5) | Combined xyz-axis (12.5) |
| Gantry revolution time (s) | 0.6 | 0.5 | 0.5 |
| Beam collimation (mm) | 64 × 0.625 | 128 × 0.625 | 128 × 0.625 |
| Beam pitch | 1.375 | 0.992 | 0.992 |
| Scan field of view (cm) | 32 × 32 | 32 × 32 | 32 × 32 |
| Image reconstruction | |||
| Display field of view (cm) | 28 × 28–40 × 40 | 29 × 29–41 × 41 | 32 × 32 |
| Section thickness (mm) | 1.25 | 1.25 | 1.25 |
| Section overlap (mm) | 1 | 1 | 1 |
| Kernel | Lung | Lung | Lung |
| Algorithm | FBP | ASiR-V 0%, 20%, 40%, 60%, 80%, and 100% | ASiR-V 0%, 20%, 40%, 60%, 80%, and 100% |
ASiR-V = adaptive statistical iterative reconstruction-V, CTDIvol = volume computed tomography dose index, FBP = filtered back-projection, MDCT = multidetector computed tomography, *phantom only.