%0 Journal Article %A Han Gyu Kang %A Sodai Takyu %A Nishikido Fumihiko %A Taiga Yamaya %T A staggered three-layer DOI PET detector with a 1 mm crystal pitch for a high resolution small animal PET imaging %D 2019 %J Journal of Nuclear Medicine %P 529-529 %V 60 %N supplement 1 %X 529Objectives: Development of a staggered three-layer DOI PET detector with a 1 mm crystal pitch for realizing a 0.7 mm resolution small animal PET imager of 52 mm ring diameter. Methods: The proposed small animal DOI PET detector consists of three-layer staggered LYSO crystal arrays, an acrylic light guide with a thickness of 1 mm, and 4×4 SiPM (Hamamatsu, S13360-3050NE-04, Japan) array with a pixel pitch of 3.2 mm. The LYSO crystal had a dimension of 0.9 × 0.9 × 5.0 mm3 with a pitch of 1 mm. The 1st (10 × 9), the 2nd (10 × 10), and the 3rd (11 × 11) LYSO layers were stacked with a staggered configuration to provide DOI information in the 2D crystal map. In order to investigate the optimal reflector and light guide thickness, the performance of the PET detector module was evaluated with different reflectors (ESR and BaSO4), and different light guide thicknesses (0.5, 1.0, and 2.0 mm). A 22Na source was used to irradiate 511 keV photon to the detector module. The sixteen SiPM output signals were multiplexed into four position signals by using the Anger logic circuit, and a trigger signal was generated by using the common cathode signals. The SiPM signals were digitized by CAMAC DAQ. Results: The BaSO4 reflector resulted in better crystal identification for the three-layer staggered LYSO crystal arrays as compared to the ESR. However, the energy resolution with BaSO4 (38.8%) was worse than that of the ESR (20.3%). The acrylic light guide thickness of 1 mm resulted in the best crystal identification for both BaSO4 and ESR reflector cases. Conclusions: A staggered three-layer DOI PET detector with a 1 mm crystal pitch was developed. All the LYSO crystals could be identified clearly on the 2D flood histogram by using the BaSO4 reflector. In future, a prototype high resolution small animal DOI PET scanner will be developed by using the proposed three-layer staggered DOI PET detector module. %U