Development of a 1-dimensional sharing block detector using dual PMTs for PET

We proposed and tested a 1-dimentional 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 overlapping in one dimensionally. With this configuration, the scintillator size of the block detector can be reduced to be half of the 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 measured the position and energy response for minimum configuration; one GSO block and two dual PMTs. The size of a single GSO was 2.9mm×2.9mm×20mm. The scintillators were arranged in 8×8 matrix with multi-layer optical film inserted partly between scintillators to obtain the resolved position response. We could obtain good position and energy responses with this configuration. Next, we fabricated a 1-D sharing block detector with 5 GSO blocks and 6 dual PMTs. With this configuration, we also obtained reasonable position and energy responses. These results indicated that the proposed 1-D sharing block detector will be a promising solution for developing high resolution or low cost PET systems.