Table 5.
Camera calibration factor and dead-time constant (± SE) derived from segmented SPECT images
| Phantom | 18–680 keV wide spectrum & TEW | |||
|---|---|---|---|---|
| Region-of-interest segmentation | Threshold segmentation | |||
| Calibration factor (cps/MBq) | Dead-time constant (μs) | Calibration factor (cps/MBq) | Dead-time constant (μs) | |
| Air-3D | 9.51 ± 0.06 | 0.570 ± 0.014 | 9.25 ± 0.05 | 0.577 ± 0.012 |
| CTDI-10 | 9.58 ± 0.04 | 0.535 ± 0.010 | 9.30 ± 0.07 | 0.578 ± 0.016 |
| CTDI-16 | 9.68 ± 0.06 | 0.522 ± 0.023 | 9.36 ± 0.08 | 0.512 ± 0.032 |
| CTDI-32 | 9.69 ± 0.04 | 0.538 ± 0.009 | 9.25 ± 0.05 | 0.516 ± 0.016 |
| Jaszczak | 9.39 ± 0.04 | 0.568 ± 0.011 | 9.38 ± 0.05 | 0.565 ± 0.013 |
Method B (full-range CF), with wide-spectrum (18–680 keV) acquisition count rate, was used to derive the calibration factor and the dead-time constant. TEW: Triple-energy window scatter correction