Fig. 2
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. Two image series based on the same PET raw data were analyzed. a Without PSF (Iterative3D, 4 iterations, 16 subsets, 2-mm Gaussian filter, 336 × 336 matrix, voxel size 2.0 × 2.0 × 2.0 mm3); and b With PSF (TrueX with PSF, 4 iterations, 21 subsets, 2-mm Gaussian filter, 336 × 336 matrix, voxel size 2.0 × 2.0 × 2.0 mm3). The x-axes are the true sphere-to-background ratio from 1:1 to 15:1. The y-axes are RCs measured as RC50bg. For 10, 6, and 4 mm spheres, the lines are mean values and error bars are ± standard deviation. With PSF, the RC50bg can be > 1, and in general the 8–10 mm spheres have the highest RCs