Comparison of Absolute System Sensitivity for Different PET Scanners
| Scanner | Standard | Energy window (keV) | Time window (ns) | Absolute system sensitivity (%) |
| LFER 150 PET/CT | NU 4-2008 | 400–600 | 5 | 1.68 |
| ECAT HRRT (Siemens) (14) | NU 2-2001 | 400–650 | 6 | 2.5 |
| microPET Focus 220 (Siemens) (15) | NU 4-2008 | 350–650 | 6 | 1.18 |
| NeuroPET/CT (Photo Diagnostic Systems) (16) | NU 2-2012 | 400–650 | 7 | 2.3 |
| Vereos (Philips) (20) | NU 2-2012 | 450–613 | 4 | 2.1 |
| Discovery MI (GE Healthcare) (21) | NU 2-2012 | — | — | 4.8 |
Results of NU2 standard are corrected for activity within FOV.