@misc{oai:repo.qst.go.jp:00077149,
 author = {Kang, Hangyu and Obata, Fujino and Tashima, Hideaki and Nishikido, Fumihiko and Yamaya, Taiga and Kang, Hangyu and Obata, Fujino and Tashima, Hideaki and Nishikido, Fumihiko and Yamaya, Taiga},
 month = {Oct},
 note = {In a previous study, we developed a 4-layer depth-of-interaction (DOI) detector with 1.5 mm crystals for organ-dedicated PET application. However, the crystal size was not appropriate for submillimeter small animal imaging. The aim of this study was to develop a 4-layer DOI detector with a 1 mm crystal pitch to develop a submillimeter resolution small animal PET scanner. The proposed 4-layer DOI detector consisted of an 8 × 8 LYSO crystal array (1 × 1 × 5 mm3) stacked in 4 layers which yielded a total thickness of 20 mm, an acrylic light guide (13 × 13 × 1 mm3), and a 4×4 SiPM array (S13361-3050NE-04, Hamamatsu Photonics, Japan) with a pixel pitch of 3.2 mm. The DOI information was encoded into a 2D flood histogram by using the combination of an enhanced specular reflector and room temperature vulcanized (RTV) rubber on the side surface of the LYSO crystal. Sixteen SiPM output signals were multiplexed into four positional signals (A, B, C, and D) using a charge division circuit, and then digitized by using CAMAC DAQ. A 22Na point source was used to irradiate 511 keV gamma photons to the LYSO crystal array. The 4-layer DOI information could be encoded into the 2D flood histogram with a crystal identification rate of 89% based on the visual check. The energy resolutions of the 1st, 2nd, 3rd, and 4th layers were 11%, 15%, 13%, and 32%, respectively. In conclusion, we developed a single-ended readout 4-layer DOI detector with a 1 mm LYSO pitch and total thickness of 20 mm. In the future, we plan to improve the crystal identification rate further to 100% by optimizing the reflector material and light guide design. After the optimization of the detector performance, we will develop a prototype small animal PET scanner for submillimeter high-resolution and high-sensitivity preclinical molecular imaging., 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference},
 title = {A Single-Ended Readout 4-Lyer DOI Detector with a 1 mm Crystal Pitch for Small Animal PET Imaging},
 year = {2019}
}