Development of Si-PM Based Imaging Systems for Molecular Imaging

Silicon photomultiplier (Si-PM) is a promising photodetector for PET for the use in magnetic resonance imaging (MRI) systems because it is insensitive to static magnetic fields. Si-PM is also a promising for high resolution PET systems due to its small channels and high gain.  We have developed several Si-PM based imaging systems for molecular imaging. First, we developed a high resolution Si-PM based PET system for small animals and tested its performance. The Si-PM PET system had 1.6mm FWHM resolution. Then we combined it into the MRI and simultaneous measurements were conducted. Although there were some interference between PET and MRI, images could be obtained with reasonable signal-to-noise ratio (S/N) on both modalities without any distortion. Finally we explored to improve the spatial resolution of the Si-PM PET system by reducing the scintillator size to be around 0.6mm pixels. We could resolve all pixels on the SiPM based detectors. We conclude the Si-PM is a promising photodetector for the development of imaging systems for