Table 4.
Image quality consistency thresholds for the small(S20) CBCT
| Warning (%) | Action (%) | |
|---|---|---|
| High contrast spatial resolution(lp/mm) | ||
| f30 | 8 | 16 |
| f40 | 5 | 11 |
| f50 | 5 | 11 |
| HU constancy | ||
| Lung(PMP) | 5 | 9 |
| Water(Poly) | 3 | 6 |
| Air | 2 | 5 |
| Uniformity | ||
| Mean | 3 | 6 |
| Sigma | 5 | 10 |
| Noise | ||
| Mean | 3 | 6 |
| Sigma | 6 | 11 |
Sample size of 30 measurements.