State-of-the-Art PET Scanners: Other Features (Factory Data)
| Feature | ALLEGRO (Philips-ADAC) | C-PET (Philips-ADAC) | ECAT ART (CTI-Siemens) | ECAT EXACT (CTI-Siemens) | ECAT EXACT HR+ (CTI-Siemens) | ECAT ACCEL (CTI-Siemens) | ADVANCE/ADVANCE Nxi (General Electric) |
|---|---|---|---|---|---|---|---|
| Energy resolution (FWHM) | 15% | 10% | ≈25% | ≈25% | ≈25% | ≈25% | ≈25% |
| Filtered backprojection | Yes (3D) | Yes (3D) | Yes (3D) | Yes (2D/3D) | Yes (2D/3D) | Yes (2D/3D) | Yes (2D/3D) |
| Iterative algorithms | FORE/OSEM | FORE/OSEM | FORE/OSEM | OSEM (2D) | OSEM (2D) | OSEM (2D) | OSEM (2D) |
| 3D-RAMLA | 3D-RAMLA | FORE/OSEM | FORE/OSEM | FORE/OSEM | |||
| Transmission source | 137Cs | 137Cs | 137Cs | 68Ge | 68Ge | 68Ge | 68Ge |
| Source activity (MBq) | 740 (×1) | 185 (×1) | 555 (×2) | 120 (×3) | 140 (×3) | 185 (×3) | 370 (×2)* |
| Source geometry | Point source | Point source | Point source | Rod | Rod | Rod | Rod |
| Transmissive energy window (keV) | 600–720 | 595–860 | 587–825 | 350–650 | 350–650 | 350–650 | 300–650 |
| Whole-body scan length (cm) | 198 | 168 | 195 | 195 | 195 | 195 | 170 |
↵* One additional 55.5-MBq 68Ge rod is also installed (for calibration only).
FORE = Fourier rebinning algorithm; OSEM = ordered-subsets expectation maximization algorithm; 3D-RAMLA = 3D row-action maximum-likelihood algorithm.