Multi head compton camera system for nuclear medicine: Simulation study

PET (Positron Emission Tomography) and SPECT (Single Photon Emission Computed Tomography) systems are expected to improve the accuracy in identifying disease targets through molecular imaging. However, both systems suffer from some disadvantages. PET is restricted to use of few radionuclide. The gamma-ray detection efficiency in SPECT system is very low due to its collimator. We have developed a new gamma-ray camera system called CPT(ComPton Tomography) camera system using ETCC(Electron Tracking Compton Camera) to overcome these limitations while still preserving the advantages of molecular imaging[1]-[6]. This system needs no mechanical collimator, and can adapt to radionuclide with various gamma- ray energies. We have already reported our new image reconstruction technique suitable for this system in 2006 IEEE NSS and MIC [5]. In this paper, we estimate the visibility of hotspots in background with GEANT4 simulation. Furthermore, we confirm that the hotspot visibility is improved using new image correction technique.