Table 1.
Acquisition technique and scan parameters of the four CT scan protocols used in this study.
| Protocol | Acquisition technique | kVp | Time [s]* Current [mA] | Reconstruction algorithm | Covered axial thickness (mm) | Image thickness (mm) | CTDIvol [mGy] |
|---|---|---|---|---|---|---|---|
| 1 (QCT) | Axial | 80 | 200 | FBP | 8 | 8 | 7.5 |
| 2 | Volume | 80 | 200 | FBP | 60 | 8 | 5.0 |
| 3 | Helical | 80 | Variable-AEC | FBP | 64 | 8 | 6,8 |
| 4 | Helical | 80 | Variable- AEC | iterative | 64 | 8 | 1,7 |
Protocol 1 (QCT) served as reference. AEC (Automatic Exposure Control) adapts the tube current to the body shape and tissue absorption. The modulation ranges from 10 mA to 800 mA.