Fig. 2

Comparison of the tumour/background ratios (TBRs) in 3D-OSEM-reconstructed (a) and PSFallpass-reconstructed (b) head-and-neck (HN) PET data sets for each of the five acquisition times per bed position from 2 to 10 min with a 2-min increment. c Comparison of the TBRs between 3D-OSEM and PSFallpass-reconstructed HN PET data sets