@inproceedings{oai:repo.qst.go.jp:00077044,
 author = {Akamatsu, Go and Takyu, Sodai and Yoshida, Eiji and Nitta, Munetaka and Iwao, Yuma and Mohammadi, Akram and Tashima, Hideaki and Nishikido, Fumihiko and Yamashita, Taichi and Yamaya, Taiga and Akamatsu, Go and Takyu, Sodai and Yoshida, Eiji and Nitta, Munetaka and Iwao, Yuma and Mohammadi, Akram and Tashima, Hideaki and Nishikido, Fumihiko and Yamashita, Taichi and Yamaya, Taiga},
 book = {2018 IEEE Nuclear Science Symposium and Medical Imaging Conference Proceedings (NSS/MIC)},
 month = {Sep},
 note = {Abstract: 
Time-of-flight (TOF) PET improves image quality and quantitative accuracy compared with a conventional PET system. While it is true that TOF works better for larger objects, recent improvement in timing resolution has encouraged
application of TOF to brain-dedicated PET systems. Thus, as the second prototype of the helmet-type PET, we have developed a new TOF brain-dedicated PET prototype using detector modules of 12×12 lutetium fine silicate (LFS) crystals (4.1×4.1×10 mm3) connected to a 12×12 (4 mm pitch, 144-ch) MPPC array. In this paper, we investigated another detector module, which has the same outer size but smaller crystals: 16×16 LFS of 3.1×3.1×10 mm3 size coupled to 16×16 (3 mm pitch, 256-ch) MPPC array. The 3-mm 256-ch module showed an energy resolution of 12.0%. For the coincidence response function, the 3-mm module showed a better full width at half maximum (FWHM) of 1.9 mm compared with the 4-mm 144-ch module (2.4 mm). The FWHM was improved by 21%. The coincidence resolving time obtained by the 3-mm 256-ch module was 241 ps. The energy resolution and coincidence resolving time were almost the same between the two modules. The 3-mm 16×16 MPPC-based TOF-PET module can be expected to improve spatial resolution without compromising the energy resolution and coincidence resolving time compared with the 4-mm 12×12 module.},
 publisher = {IEEE},
 title = {Characterization of LFS MPPC PET-detector modules: 3 mm pitch vs. 4 mm pitch},
 year = {2019}
}