Development of a one-dimensional sharing block detector using dual PMTs for PET

We propose and test a one-dimensional (1-D) sharing block detector using dual photo-multiplier tubes (PMT). The detector consists of scintillator blocks and dual PMTs. The dual PMTs are optically coupled on the scintillator blocks and overlap in one dimensional. With this configuration, the scintillator size of the block detector can be reduced to half that of a conventional block detector in one direction, and isotropic spatial resolution can be obtained in transaxial and axial directions using commercially available dual PMTs. First, we measure the position and energy response for minimum configuration; one GSO block and two dual PMTs. The size of a single GSO is 2.9 mm × 2.9 mm × 20 mm. The scintillators are arranged in an 8 x 8 matrix with multi-layer optical film inserted partly between scintillators to obtain the resolved position response. We obtain good position and energy responses with this configuration. Next, we fabricate a 1-D sharing block detector with five GSO blocks and six dual PMTs. With this configuration, we also obtain reasonable position and energy responses. These results indicate that the proposed 1-D sharing block detector is a promising solution for developing high-resolution and low cost PET systems.