Phantom A: Average CT Attenuation (HU) and PET Activity (kBq/mL) and SD in ROIs at Center (ROI_c) and Edge (ROI_e)
| Image | Phantom position | ROI_c (HU) | t test (P value) | ROI_e (HU) | t test (P value) |
|---|---|---|---|---|---|
| CT | Center | −1 ± 9 | NA | −1 ± 7 | 0.5 (NS) |
| offset_trunc | −5 ± 14 | <0.001 | — | NA | |
| offset_ext | −10 ± 9 | <0.001 | −150 ± 70 | <0.001 | |
| (kBq/mL) | (kBq/mL) | ||||
| PET | Center | 9.7 ± 0.5 | NA | 9.7 ± 0.4 | 4.6 (NS) |
| offset_trunc | 9.7 ± 0.5 | 4.6 (NS) | 1.7 ± 0.8 | <0.001 | |
| offset_ext | 9.4 ± 0.5 | <0.001 | 8.7 ± 0.5 | <0.001 |
NA = not applicable; NS = not statistically significant.
For location of ROIs, see Figure 1A. P values for CT and PET indicate statistical significance in a 2-tailed, paired Student t test with Bonferroni correction in reference to central ROI (ROI_c).