A new method for position determination of scintillation pixel in PET detector module using simulation LUT and MLPE

A new method was developed to determine the positions where the scintillation pixels and gamma rays of the positron emission tomography (PET) detector module interact. A simulation look-up table (LUT) was created to determine the positions of the scintillation pixels via maximum likelihood position estimate (MLPE). To create the LUT, a DETECT2000 simulation was performed using a 6 x 6 array of scintillation pixels and SiPM photo sensor with a 4 x 4 array. The light signals obtained through the gamma interaction generated at the center of each scintillation pixel were reduced to 4 channels through the Anger equation, and the LUT was created using the ratios of each channel. As a result of applying this data obtained by an experiment, it showed an accuracy of 90%. Although the LUT was created by the simulation, this method can be applied to the conventional detector module because the position of the scintillation pixel is determined through MLPE using the ratio of each channel. When using this new method, it is possible to obtain the position of the scintillation pixel as digital coordinates without performing additional processes by changing a conventional system.