Fig. 5
From: Point-spread function reconstructed PET images of sub-centimeter lesions are not quantitative
Spheres in 11C-silicone scanned on Siemens Biograph 64 Truepoint PET/CT. RC50bg (a) and RCavg (b) as function of iterations and sphere size for true sphere-to-background ratio around 8:1. Images were reconstructed with varying iterations (the number of subset was kept constant: 16 without PSF and 21 with PSF) and post-filter widths using a 336 × 336 × 109 matrix with a voxel size 2.0 × 2.0 × 2.0 mm3. For 10, 6, and 4 mm spheres, the symbols are mean values and error bars are ± standard deviation. Note: the VOI used for the 3 mm consists of only 1 voxel. Thus, for the 3-mm sphere RCavg is equal to RCmax. With PSF and a narrow (2 mm) post-filter, the RC measures are non-monotonic function of sphere size (maximum 8–10 mm diameter); whereas wider post-filters suppress the PSF artifacts. Note the different scales on the y-axes