Study of a PET detector module with LSO scintillation crystals and an APD array

Detailed results are given for the study of the spatial resolution obtained with different configurations of LSO scintillation crystals read out by a Hamamatsu 2/spl times/8 APD array. Block detectors as well as small sited individual LSO crystals have been coupled to the APD matrix. Both one-to-one coupling and light sharing schemes were investigated. The spatial resolution is derived for each configuration. Two different configurations with two layers of LSO crystals shifted by half a crystal size with respect to each other are used for investigations on the depth-of-interaction (DOI) information. Prior to the spatial resolution measurements, a comparison of the light output for various crystal surface treatments and different optical coupling materials has been made.