Fig. 5
From: Fast quantitative reconstruction with focusing collimators for liver SPECT
Projections of the NEMA phantom made with the GATE Monte Carlo projector (top row) and with the fast Monte Carlo projector (middle row) for the parallel hole, cone beam (50 cm), cone beam (100 cm), and multifocal collimators. Profiles along the middle spheres are shown in the bottom row. The GATE Monte Carlo projections are generated with 2.6, 4.1, 2.7, and 2.6 billion photons, respectively