Simulation of detectors for biomedical imaging

The goal of this lecture is to provide basic information on the role of computer simulations in the investigation of the properties of semiconductor radiation detectors, when evaluating the predicted response of biomedical imaging systems under development. It will be presented some examples on the simulation of the response of room-temperature radiation detectors (Si, GaAs, CdTe) for medical imaging, and their comparison with experimental data. Simulations with the EGS4 Monte Carlo code will include pencil X-ray beam irradiation of thick semiconductors substrates in the 10-100 keV diagnostic energy range, in order to extract information on the intrinsic spectroscopic and spatial resolution performance of detectors for digital radiography. The problem of the simulation of the electric field internal to biased compound semiconductor detectors will be addressed. Examples of Monte Carlo simulations for detector response characterization in nuclear medicine (PET, scintigraphy) will also be shown.