Modern devices for PET (Positron Emission Tomography) are an interesting example for the integration of a number of recent developments. Among them are the highly efficient detection of high energetic photons (energy range from 50 to 700 keV) by scintillating crystals (LSO, LYSO, GSO), capturing the scintillation light with solid-state detectors (APD, SiPM) and processing the electric pulses with very fast, yet compact electronics with reduced heat build-up.
Within the framework of hybrid imaging (MR-PET) it is also required, that such detectors including the electronics can be placed into strong magnetic fields with fast varying gradients. Besides that the detectors should be fully operational, they must not deteriorate the data taking of the MR systems.
Simulation of Medical Imaging Devices
The simulation of medical imaging devices has proven to be an effective tool for the development of new detector designs, but also during the configuration of complete systems. Also, simulation plays a major role during the development of new and very fast reconstruction algorithms. Owing to the availability of cheap computer systems with high performance, the simulation of very complex systems as a whole is possible. This includes taking into account various physical effects, namely the interaction of highly energetic photons with surounding material, but also the distribution of scintillations light in the crystals.
For our current studies the GATE simulation platform is applied. GATE was developed by the „OpenGATE Collaboration“ (http://www.opengatecollaboration.org/) based on the GEANT4-package (CERN) (http://geant4.web.cern.ch/geant4/). Its most important feature among many others is the precise treatment of all occurring physical effects. It was especially developed for the application in emission tomography like PET and SPECT, but recently also includes aspects of radiation therapy and X-ray CT.