WEKO3
アイテム
First 89Zr mouse demonstration of whole gamma imaging (WGI)
https://repo.qst.go.jp/records/76199
https://repo.qst.go.jp/records/76199ffaff903-1776-4e2c-a610-c6f03df4c2a2
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2019-06-10 | |||||
| タイトル | ||||||
| タイトル | First 89Zr mouse demonstration of whole gamma imaging (WGI) | |||||
| 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 |
Tashima, Hideaki
× Tashima, Hideaki× Yoshida, Eiji× Wakizaka, Hidekatsu× Takahashi, Miwako× Nagatsu, Kotaro× Tsuji, Atsushi× Kamada, Kei× Parodi, Katia× Yamaya, Taiga× Tashima, Hideaki× Yoshida, Eiji× Wakizaka, Hidekatsu× Takahashi, Miwako× Nagatsu, Kotaro× Tsuji, Atsushi× Parodi, Katia× Yamaya, Taiga |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | [Objectives] Whole gamma imaging (WGI) is our original idea of a combined PET and Compton camera to utilize diverse types of gamma rays for 3D tomographic imaging. Last year, we presented the first prototype of the WGI, where a scatterer detector ring was inserted into a PET ring (an absorber ring). Spatial resolution in three different imaging modes, the PET mode, the Compton imaging mode and the triple gamma mode, was discussed by measuring point-like radioactive sources of 22Na, 137Cs and 44Sc, respectively. In this study, we demonstrate the first mouse imaging performance of WGI. For better spatial resolution of Compton imaging, the diameter of the scatterer ring was half-sized so as to arrange the detectors as close as possible to an imaging subject. [Methods] The absorber detector ring of the WGI prototype was formed with 160 four-layer depth-of-interaction (DOI) detectors each consisting of a 16x16x4 array of 2.8x2.8x7.5-mm3 GSO crystals and a 64-ch photomultiplier tube. The DOI detectors were arranged into 4 rings of 40 detector blocks with the inner diameter of 660 mm. The scatterer detector ring was formed with 20 detectors each consisting of a 24x24 array of 0.9x0.9x6.0-mm3 GAGG crystals and an 8x8 array of multi pixel photon counters (3-mm pixels). The scatterer detectors were arranged in 2 rings of 10 detector blocks with the inner diameter of 94 mm. Compared with the previous development having scatterer diameter of 200 mm, we expected not only the sensitivity improvement by making the detectors closer but also the spatial resolution improvement to be about half as it is almost proportional to the distance from the scatterer detectors. To demonstrate the single-gamma imaging capability of the WGI prototype, we conducted small animal study using 89Zr, which emits both 909-keV gamma rays and positrons with a 15.7-s time difference in the half life. By setting energy window appropriately, we acquired two difference images, a 909-keV image by the Compton imaging mode and a 511-keV image by the PET mode; each was obtained from the same list-mode data. As the tracer distribution was the same for both images, we could directly compare the imaging capability of two different methods.[Results] We measured a mouse for 1 hour 1 day after the 89Zr-Oxalate injection of 10 MBq. The 511-keV image reconstructed using list-mode data within the energy window of 350-600 keV for the scatterer ring only, which was selected after the measurement, clearly showed the bone structure of the mouse because the 89Zr-Oxalate accumulates bone and soft bone. Also, we could obtain a 909-keV image by applying a Compton image reconstruction method for extracted coincidence events between the scatterer ring and the absorber ring within the energy window of 50-350 keV and 550-850, respectively, and within the total energy of 800-1000 keV. Although the spatial resolution was inferior, the 909-keV images were well correlated to the 511-keV image. [Conclusions] We demonstrated the ability of the WGI for small animal single gamma imaging. The result showed that the tomographic Compton imaging is feasible with the WGI for high energy single gamma rays. |
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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 | SNMMI 2019 Annual Meeting | |||||
| 発表年月日 | ||||||
| 日付 | 2019-06-23 | |||||
| 日付タイプ | Issued | |||||
