| ROI No. | simCT | rCBCT | mCBCT | |||
| HU | rCBCT value | % difference in REDrCBCT | mCBCT value | % difference in REDmCBCT | ||
| off-center −7.0 cm (superior) | ||||||
| 1 | −87 ± 29 | −493 ± 24 | −14.74% ± 3.43% | −95 ± 36 | −0.83% ± 1.50% | |
| 2 | 54 ± 7 | −312 ± 33 | −2.43% ± 2.78% | 46 ± 13 | −0.38% ± 0.48% | |
| 3 | 415 ± 55 | −40 ± 152 | 3.21% ± 11.22% | 393 ± 57 | −0.92% ± 1.05% | |
| (mean ± 1SD) | (−4.66% ± 10.09%) | (−0.71% ± 1.04%) | ||||
| off-center 0.0 cm (center) | ||||||
| 4 | 36 ± 8 | −329 ± 46 | − 2.26% ± 3.88% | 29 ± 7 | −0.36% ± 0.23% | |
| 5 | −97 ± 23 | −413 ± 44 | − 0.86% ± 5.90% | −99 ± 20 | −0.26% ± 0.65% | |
| 6 | 59 ± 6 | −267 ± 55 | 1.24% ± 4.57% | 67 ± 14 | 0.37% ± 0.40% | |
| 7 | 286 ± 72 | −147 ± 83 | 0.76% ± 7.53% | 301 ± 69 | 0.64% ± 1.01% | |
| (mean ± 1SD) | (−0.28% ± 5.37%) | (0.10% ± 0.73%) | ||||
| off-center 7.0 cm (inferior) | ||||||
| 8 | −96 ± 15 | −458 ± 77 | −8.76% ± 11.06% | −111 ± 18 | −1.62% ± 0.64% | |
| 9 | 61 ± 5 | −287 ± 67 | −0.05% ± 4.98% | 69 ± 3 | 0.37% ± 0.32% | |
| 10 | 772 ± 223 | 146 ± 123 | 2.51% ± 11.20% | 763 ± 240 | −0.37% ± 0.78% | |
| (mean ± 1SD) | (−2.10% ± 10.14%) | (−0.54% ± 1.02%) | ||||
| Total mean ± 1SD | −2.14% ± 8.54% | −0.34% ± 0.97% | ||||