GATE Simulation of a Clinical PET Scanner : Influence of Windows Timing Coincidences and Dead Time on Count Rate Performance

This paper present an evaluation of the Count rate performance and noise equivalent count rate (NECR) in different coincidence timing windows arranging from 8 to 12 ns, with different dead-time electronic 5000ns paralyzable and 4900ns nonparalyzable. The clinical PET ECAT EXACT HR+ is validated according to the National Electrical Manufacturers Association (NEMA NU 2-2012). The simulated results (scatter fraction (SF), sensitivity(S) and NECR) show a good agreement with the experimental data. the results show that decreasing the coincidence time windows cause a decrease of 28% of the NECR. Moreover, the NECR is increased by 4,28% using 4900ns non paralyzable deadtime instead of 5000ns parlyzable. Keywords—PET, scatter fraction, sensitivity, NECR, dead time