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Elimination of Inter Crystal Scattering Events in the X'tal Cube PET Detector with (0.77 mm)3 Segments
https://repo.qst.go.jp/records/73061
https://repo.qst.go.jp/records/73061a1e7cc91-c39c-41ba-8db8-92985071fb36
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2018-11-27 | |||||
| タイトル | ||||||
| タイトル | Elimination of Inter Crystal Scattering Events in the X'tal Cube PET Detector with (0.77 mm)3 Segments | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Nitta, Munetaka
× Nitta, Munetaka× Nishikido, Fumihiko× Inadama, Naoko× Tashima, Hideaki× Kawai, Hideaki× Yamaya, Taiga× 新田 宗孝× 錦戸 文彦× 稲玉 直子× 田島 英朗× 山谷 泰賀 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | We have developed the X’tal cube PET detector which ‘ is composed of 96 multi pixel photon counters (MPPCs) and a (13.1 mm)3 LYSO scintillator segmented into the 17 x 17 x 17 array. Each segment size is (0.77 mm)3. Six 4 x 4 MPPC arrays cover all six surfaces of the LYSO scintillator. The Anger calculation from 96 MPPC signals is used to determine the segment detecting a gamma-ray. We confirmed that the X’tal cube achieved sub-millimeter isotropic spatial resolution. However, we also observed inter crystal scattering (ICS) events as background events. There is a concern that ICS events degrade contrast of PET images for the high spatial resolution PET scanner. \n We proposed a method to discriminate the ICS events and applied it to the X’tal cube. If the photo absorption event occurs at one segment, the distribution of spread light on each MPPC is the same for every event. On the other hand, even if the result of the Anger calculation is the same as the photo absorption event, the distribution of spread light by the ICS events differs from that of the photo absorption event because scintillation light is generated at different segments. To discriminate the ICS events, first using a uniform irradiation experiment, we obtained the mean and standard deviation of pulse height peak of each MPPC for the segment to set the threshold for the discrimination of the ICS events. Then for each detected event, each MPPC pulse height was measured and the chi-square value was calculated. If the chi-square value exceeded the threshold, the event was eliminated as an ICS event. Next, to prove that our method can eliminate the ICS events, we obtained the response function by a fan-beam scanning experiment. We compared the results before and after applying our method. At the central part of the X’tal cube, full width half maximum of the ICS distribution in the response function was improved from 4.0 mm to 2.1 mm and over 50% of the ICS events were eliminated. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | IEEE NSS-MIC2018 | |||||
| 発表年月日 | ||||||
| 日付 | 2018-11-16 | |||||
| 日付タイプ | Issued | |||||
