Fig. 9.
Sphere phantom in air reconstructed with 20 iterations of list-mode 3D-OSEM on (a) the GPU and (b) the CPU, using Gaussian kernel with 1 mm FWHM. The spheres extend to the edge of the 8 × 8 × 8 cm3 FOV and their size is 1, 1.25, 1.5, and 1.75 mm. The spacing between the centers is twice the diameter. (c) Profile through the 1.75 mm spheres for both reconstructions.