NEMA NU-2 Measurements for Other Commercial PET Scanners
| GE Healthcare | Siemens Healthcare | Philips Healthcare | |||||
| Parameter | Discovery MI PET/CT (this work) | SIGNA PET/MR (12) | Discovery 690/710 PET/CT (4) | Biograph mCT Flow PET/CT (7) | Biograph mMR PET/MR (14) | Vereos Digital PET/CT (20) | Ingenuity TF 128 PET/CT (8) |
| Axial FOV (cm) | 20 | 25 | 15.7 | 22.1 | 25.8 | 16.4 | 18 |
| Transverse FOV (cm) | 70 | 60 | 70 | 70 | 59.4 | 67.6 | 67.6 |
| Detector ring diameter (cm) | 74.4 | 62.4 | 81.0 | 84.2 | 65.6 | 76.4 | 90 |
| Crystal thickness (mm) | 25 | 25 | 25 | 20 | 20 | 19 | 22 |
| Spatial resolution FWHM* | |||||||
| Radial, 1 cm | 4.10 | 4.46 | 4.70† | 4.33† | 4.3† | 4.01† | 4.84† |
| Tangential, 1 cm | 4.19 | 4.08 | 4.70† | 4.33† | 4.3† | 4.01† | 4.84† |
| Axial, 1 cm | 4.48 | 5.35 | 4.74 | 4.25 | 4.3 | 4.14 | 4.73 |
| Radial, 10 cm | 5.47 | 5.81 | 5.34 | 5.16 | 5.2 | NA | 5.25 |
| Tangential, 10 cm | 4.49 | 4.44 | 4.79 | 4.72 | 4.8 | NA | 5.01 |
| Axial, 10 cm | 6.01 | 6.75 | 5.55 | 5.85 | 6.6 | NA | 5.23 |
| Radial, 20 cm | 7.53 | 8.42 | NA | 5.55 | NA | 5.82† | NA |
| Tangential, 20 cm | 4.90 | 5.27 | NA | 6.48 | NA | 5.82† | NA |
| Axial, 20 cm | 6.10 | 7.30 | NA | 7.80 | NA | 6.17 | NA |
| Center of FOV (cps/kBq) | 13.7 (7.5‡) | 22.9 | 7.4 | 9.6 (5.4§) | 15.0 | 5.7 | 7.39 |
| Counting rate statistics | |||||||
| Peak NECR (kcps) | 193.4 | 214.8 | 139.1 | 185 | 184 | 171 | 124.1 |
| Peak NEC activity (kBq/mL) | 21.9 | 17.6 | 29.0 | 29.0 | 23.1 | 50 | 20.3 |
| Peak NEC scatter fraction (%) | 40.6 | 42.5 | 37 | 33.5 | 37.9 | 30 | 36.7 |
| Maximum absolute error (%) | 3.14 | 3.5 | 2.09 | 3.7 | 5.5 | NA | NA |
| Contrast recovery in spheres | |||||||
| 10 mm | 53.7 | 36.5 | 44 | 28.5 | 32.5 | 62 | 17 |
| 13 mm | 64.0 | 50.6 | 56 | 42.3 | 50.0 | NA | 46 |
| 17 mm | 73.1 | 60.0 | 65 | 58.4 | 62.9 | NA | 58 |
| 22 mm | 82.7 | 68.6 | 75 | 71.7 | 70.8 | 88 | 63 |
| 28 mm | 86.8 | 80.7 | 87 | 70.1 | 65.1 | 86 | 68 |
| 37 mm | 90.7 | 88.6 | 89 | 78.3 | 72.3 | 89 | 68 |
| Timing resolution (ps) | 375.4 | 390 | 544.3 | 555∥ | 2,930 | 322 | 502 |
| Energy resolution (%) | 9.40 | 10.5 | 12.4 | NA | 14.5 | 11.0 | 11.1 |
↵* Filtered backprojection.
↵† Radial and tangential values are averaged.
↵‡ With 15-cm axial FOV (16).
↵§ With 16.2-cm axial FOV (11).
↵∥ Value is unclear in reference.
NA = not applicable; NEC = noise-equivalent count.
For each column, numeric precisions are exactly as presented in that reference. The Discovery 690 and 710 have same PET subsystem, so the NEMA results apply to both. The Vereos Digital is not yet commercially available.