Abstract
The recent development of small semiconductor photodetectors such as multi-pixel photon counters (MPPCs) that can replace conventional photomultiplier tubes is leading researchers to create new PET detectors. The National Institute of Radiological Sciences is therefore developing a next-generation PET detector known as "X'tal Cube" in collaboration with Chiba University, Tokyo University, and Hamamatsu Photonics K.K. One of the most challenging aspects of this detector is implementing the effective detection of scintillation photons by optically covering all 6 surfaces of a segmented crystal block with MPPCs. From the viewpoint of positional determination, however, a redundant signal from the scintillation photons is acquired for the X'tal Cube. In this report, we propose a new method for improving the accuracy of positional determination by selecting data containing a large amount of positional information. The proposed method is combined with the conventional Anger-type calculation, which is known as a center of gravity operation method for positional estimation. The results of Monte Carlo simulations showed that selecting the data of only 4 effective faces resulted in superior determination performance as compared to using the data of all 6 faces.
