Table 3 Specifications of commercially available TOF-PET/MR systems

Scintillator

LYSO

LBS

Photo-detector

PMT

SiPM

Scintillator size (mm³)

4 ×4×22

4 ×5.3×25

Total detector elements

28,336

20,160

Bore/detector diameter (cm)

70.7/90.3

60/

Axial length (cm)

18

25

Resolution (in mm)

Transaxial at 1 cm/10 cm (mm)

4.7/5.15

4.2/5.2

Axial at 1 cm/10 cm (mm)

4.6/5.0

5.8/7.1

Energy resolution (%)

11.6

11

Lower energy threshold (keV)

460

425

Scatter fraction (%)

26

43.6 at peak NECR

Sensitivity (cps/kBq)

7.0

21

Coincidence window (ns)

6

4.57

Peak NEC (kcps at kBq/mL)

88.5 at 13.7

210 at 17.5

TOF bin size (ps)

25

NA

TOF resolution (ps)

525

400