Table 3.
Reconstruction and quantification parameters and processing software used in this study
| System | Discovery NM/CT 670 Pro | Precedence 6 | Symbia Intevo 6 | Symbia T16 system 1 | Symbia T16 system 2 | All |
|---|---|---|---|---|---|---|
| Imaging center | Leiden University Medical Center | Maastricht University Medical Center | Noord West ziekenhuis Groep | Radboud University Medical Center | Erasmus University Medical Center | All |
| Reconstruction | OSEM* + Evolution with PSF* correction | OSEM* + Astonish with PSF* correction | Weighted Conjugate Gradient + xSPECT with PSF* correction | OSEM* + Flash 3D with PSF* correction | OSEM* + Hybrid Recon V1.2 with PSF* correction | OSEM* + Hybrid Recon V1.2 with PSF* correction |
| Quantification | Q.Metrix | Manual analysis | xSPECT Quant | Manual analysis | Hermes SUV SPECT | Hermes SUV SPECT |
| Iterations | 9 [5] | 3 | 24 | 6 | 5 | 5 |
| Subsets | 10 | 16 | 2 | 16 | 16 | 16 |
| Post-reconstruction filter | None | None | 7.5 mm (Gaussian) | 8.4 mm (Gaussian) | 5 mm (Gaussian) | 5 mm (Gaussian) |
| Processing | GE Xeleris 4.0 workstation | Philips Extended Brilliance Workspace | Siemens Syngo.via | Siemens Inveon Research Workplace | Hermes Hybrid Viewer | In-house developed Python algorithm |
| Attenuation correction | CT-based, bilinear conversion of HU into attenuation coefficients at 140 keV | CT-based, HU segmentation using a step-like law, bilinear conversion of HU into attenuation coefficients at 140 keV | CT-based, bilinear conversion of HU into attenuation coefficients at 140 keV | CT-based, bilinear conversion of HU into attenuation coefficients at 140 keV | CT-based, Bilinear conversion of HU into attenuation coefficients at 140 keV | CT-based, bilinear conversion of HU into attenuation coefficients at 140 keV |
| Scatter Correction | DEW* (120 keV ± 10%) | Kernel based | DEW* (119 keV ± 7.5%) | DEW* (119 keV ± 10%) | Monte Carlo-based | Monte Carlo-based |
| Image voxel size | 2.21 × 2.21 × 2.21 mm3† | 4.7 × 4.7 × 4.7 mm3 | 2.54 × 2.54 × 2.54 mm3 | 4.8 × 4.8 × 4.8 mm3 | 4.8 × 4.8 × 4.8 mm3 | 4.8 × 4.8 × 4.8 mm3 |
* OSEM ordered subset expectation maximization, PSF point spread function, DEW dual energy window
† Initial acquisition was performed with 128 × 128 matrix size and corresponding voxel size of 4.42 × 4.42 × 4.42 mm3. For quantification purposes this was interpolated to a 256 × 256 matrix size and corresponding voxel size of 2.21 × 2.21 × 2.21 mm3, as recommended by the vendor.