Table 2.
Comparison of PET/CT system performance.
| Parameter | 5‐ring DMI (this work) | 4‐ring DMI7, 8 | 3‐ring DMI11 | Discovery IQ12, 13 | Signa PET/MR14, 15 |
|---|---|---|---|---|---|
| System specifications | |||||
| Axial/Transaxial FOV (cm) | 25/70 | 20/70 | 15/70 | 25/70 | 25/60 |
| Detector (type) | SiPM | SiPM | SiPM | PMT | SiPM |
| Scintillator type | LYSO | LYSO | LYSO | BGO | LYSO |
| Scintillator depth (mm) | 25 | 25 | 25 | 30 | 25 |
| Scintillator size (mm x mm) | 3.95 x 5.3 | 3.95 x 5.3 | 3.95 x 5.3 | 6.3 x 6.3 | 3.95 x 5.3 |
| Spatial resolution, FBP | R/T/A | R/T/A | R/T/A | Rb/Tb/ Ab | R/T/A |
| 1 cm, FWHM (mm) | 4.3/4.3/5.0 | 4.1/4.2 /4.5a | 4.4/4.8a /4.8a | 4.4c/4.1c/5.3c | |
| 10 cm, FWHM (mm) | 5.5/4.6/6.5 | 5.5/4.5/6.0 | 5.6/5.2a /4.9a | 5.8c/4.4c/6.7c | |
| 20 cm, FWHM (mm) | 7.4/5.0/6.6 | 7.5/4.9/6.1 | 8.3a /5.6a /4.7a | 8.4c/5.2c/7.3c | |
| Sensitivity (cps/kBq) | |||||
| Center | 20.8 | 13.2a | 7.5c | 23.3 | 23.1 |
| 10 cm | 20.6 | 13.1a | 20.0 | 22.5 | |
| Counting rate statistics | |||||
| PNECR (kcps) | 266 | 190a | 100c | 190a | 217a |
| PNECR activity (kBq/ml) | 20.8 | 22.2 | 20.6c | 9.5a | 17.8a |
| SF at PNECR (%) | 40.2 | 41.4 | 37a | 43.8a | |
| Max. error at PNECR (%) | 3.61 | 3.28 | 3.65 | ||
| Image Quality | |||||
| 10 mm (CR/BV; %) | 46/9.3 | 53/10.1 | 28/6.5 | 43/4.9a | |
| 13 mm (CR/BV; %) | 54/7.1 | 63/7.7 | 47/5.7 | 49/4.0a | |
| 17 mm (CR/BV; %) | 66/5.4 | 70/5.8 | 62/5.0 | 60/3.2a | |
| 22 mm (CR/BV; %) | 71/4.4 | 78/4.4 | 68/4.3 | 77/2.7 | |
| 28 mm (CR/BV; %) | 85/3.8 | 87/3.7 | 66a /3.6 | 79a /2.2 | |
| 37 mm (CR/BV; %) | 89/3.5 | 90/3.0 | 72a /3.1 | 87/1.9 | |
| Average lung error (%) | 5.9 | 6.1 | 22.2a | 3.2 | |
DMI, Discovery MI; SiPM, silicon photomultiplier; PMT, photomultiplier tube; LYSO, lutetium yttrium oxyorthosilicate; BGO, bismuth germanium oxide; FBP, filtered back projection; R/T/A, radial//tangential/axial; FWHM, full width at half maximum; PNECR, peak noise‐equivalent counting rate; SF, scatter fraction; max., maximum; CR; contrast recovery, BV, background variability.
a
Significantly different from 5‐ring DMI value.
b
FBP data are not available so results are for iterative reconstruction.
c
Insufficient data are available to determine significance.