Analysis of Intercamera Variability of H/M Ratio for Thorax Phantom
| Camera/collimator | Sample size | H/M LSM ± SE* | LSM difference ± SE* | P* |
| GE Healthcare, Millennium MG/LEHR | 10 | 1.645 ± 0.0286 | ||
| GE Healthcare, Discovery/LEHR | 8 | 1.621 ± 0.0319 | 0.024 ± 0.0429 | 0.5804 |
| GE Healthcare, Infinia/LEHR | 10 | 1.609 ± 0.0286 | 0.036 ± 0.0404 | 0.3824 |
| Philips, Vertex/VXGP or VXHR | 8 | 1.604 ± 0.0319 | 0.040 ± 0.0429 | 0.3496 |
| Siemens, e.cam/LEHR | 8 | 1.564 ± 0.0319 | 0.081 ± 0.0429 | 0.0655 |
| Siemens, Symbia/LEHR | 8 | 1.631 ± 0.0319 | 0.014 ± 0.0429 | 0.7496 |
↵* Obtained from mixed model with repeated measures on H/M ratios for first head tested as dependent variable and camera/collimator combination as independent variable. Each camera model is compared with reference camera Millennium MG (GE Healthcare).
LSM = least-squares mean; VXGP = vertex general purpose; VXHR = vertex high resolution.
Only camera/collimator categories with a sample size of at least 8 are included in model, as specified in statistical analysis plan.