@misc{oai:repo.qst.go.jp:00083760,
 author = {Hideaki, Tashima and Mohammadi, Akram and Fumihiko, Nishikido and Kang, Hangyu and Go, Akamatsu and Sodai, Takyu and Yuma, Iwao and Shinji, Sato and Hitoshi, Ishikawa and Taiga, Yamaya and Hideaki, Tashima and Mohammadi, Akram and Fumihiko, Nishikido and Kang, Hangyu and Go, Akamatsu and Sodai, Takyu and Yuma, Iwao and Shinji, Sato and Hitoshi, Ishikawa and Taiga, Yamaya},
 month = {Oct},
 note = {Small animal studies in the carbon ion therapy field are still necessary to understand cancer cell behavior deeply and to explore new medical applications. For precise irradiation with dose monitoring for small animals, PET measurement of positron emitters produced via fragmentation reactions is desired. This study compared our two recently developed small animal PET prototypes with different performance characteristics.  The first is a total body small-animal (TBS) PET prototype with a high sensitivity of 16.7% at the center, while the spatial resolution is limited to about 2 mm. The second is a crosshair light sharing (CLS) PET prototype having sub-millimeter spatial resolution while the sensitivity at the center is limited to 1.0%. Both are compact mobile scanners, which can be moved to an irradiation room at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) for offline PET measurement. Also, they have sufficient axial length for measuring a rat's total body at one time. In this study, cylindrical phantoms of 4 cm diameter and 10 cm length made of polymethyl methacrylate (PMMA) were irradiated with a 290 MeV/u 12C beam (1.2×109 pps) for 16 s. A brass collimator and a PMMA range shifter of 90 mm thickness were placed upstream to adjust the beam shape and the Bragg peak position to the phantom center. Off-line PET measurement start times after the end of irradiation and the measurement times were 5 min and 20 min for TBS PET and 6 min and 30 min for CLS PET, respectively. As a result, peaks in images obtained by TBS and CLS PET prototypes were observed respectively at 4 mm and 3 mm upstream from the Bragg peak position. The obtained image of the CLS PET was significantly noisier than that of TBS PET, although the measurement time of CLS PET was longer. The high sensitivity of the TBS PET prototype is preferred in cases where the number of produced positron emitters is limited., IEEE NSS MIC 2021},
 title = {Comparison of two small animal PET prototypes for off-line range verification in carbon beam irradiation},
 year = {2021}
}