Analysis of Intracamera Variability in H/M Ratio
| Measurement | GE Healthcare, Millennium MG/LEHR (n = 10) | GE Healthcare, Discovery/LEHR (n = 8) | GE Healthcare, Infinia/LEHR (n = 10) | Philips, Brightview/LEHR (n = 2) | Philips, Cardio 60/LEHR (n = 2) | Philips, Cardio MD/LEHR (n = 4) | Philips, Vertex/VXGP or VXHR (n = 8) | Siemens, e.cam/LEHR (n = 8) | Siemens, Symbia/LEHR (n = 8) |
| Mean ± SD | 1.648 ± 0.0776 | 1.624 ± 0.0849 | 1.607 ± 0.1193 | 1.665 (0.0257) | 1.677 ± 0.0302 | 1.342 ± 0.0262 | 1.611 ± 0.0866 | 1.566 ± 0.1118 | 1.635 ± 0.0455 |
| Median | 1.65 (range, 1.52–1.76) | 1.62 (range, 1.51–1.75) | 1.59 (range, 1.39–1.78) | 1.66 (range, 1.65–1.68) | 1.68 (range, 1.66–1.70) | 1.34 (range, 1.31–1.37) | 1.63 (range, 1.49–1.77) | 1.53 (range, 1.41–1.73) | 1.63 (range, 1.55–1.69) |
| 95% CI | 1.592–1.703 | 1.553–1.695 | 1.521–1.692 | 1.434–1.895 | 1.406–1.949 | 1.300–1.384 | 1.539–1.683 | 1.472–1.659 | 1.597–1.673 |
Analysis is based on average of H/M ratios from 2 independent readers on camera head 1 for each camera model.
n = sample size for each camera/collimator combination; VXGP = vertex general purpose; VXHR = vertex high resolution.