Accurate Simulation Testbench for Nuclear Imaging Systems

Abstract

Current testbenches for nuclear imaging devices aim to simulate only a single stage of the system at a time. This approach is useful in early design stages where accuracy is not necessary. However, it would be desirable that different tools could be combined to achieve more detailed simulations. In this work, a high precision testbench is presented. It has been developed to test nuclear imaging systems. Its accuracy lies in the possibility of linking different simulation tools using the right one for each part of the system. High energy events are simulated using Geant4 (High Energy Simulator). Analog and digital electronics are verified using SpectreVerilog or UltrasimVerilog (Cadence Design Syst. Inc., San Jose, CA, USA) and ModelSim (Mentor Graphics Corp, Wilsonville, OR, USA). This testbench structure can be used to test any physical topology, scintillation crystals, Photomultiplier Tubes (PMTs), Avalanche Photodiodes (APDs), with any kind of ASIC, discrete analog and digital electronics, thus reducing the prototyping and design time. New system developments can be easily verified using behavioral and circuital description models for analog and digital electronics. Finally, a dual-head continuous LSO scintillation crystal Positron Emission Tomography (PET) system has been used as an example for evaluation of the testbench.