Fig. 1.

Contrast recovery of BSREM (β = 300–3000, including TOF and PSF) and TOF-OSEM (3 iterations, 16 subsets, post-filter 5.0 mm and PSF) as a function of the background coefficient of variation for different acquisition times (20, 10, 5.0, 2.5, and 1.0 min) and contrast ratio of 8:1. Different plots are shown with decreasing sphere diameter