Whole gamma imager

  • 2019/4/1
    Yamaya Lab. web site open!

Introduction

Positron emission tomography (PET) plays important roles in cancer diagnosis, neuroimaging and molecular imaging research. The National Institute of Radiological Sciences (NIRS) has been focusing on PET research since 1979 when NIRS developed the first PET scanner in Japan. Now NIRS is recognized as one of the world’s leading institutions in the field of molecular imaging research.

Regarding instrumentations, potential points remain for which big improvements could be made, including spatial resolution, sensitivity and manufacturing costs. Therefore, research on next generation PET technologies remains a hot topic worldwide.

A small prototype of the world's first open-type PET "OpenPET".

Highlight

  • Recognized as a Person of Collaboration Merits by the Minister of Health, Labour and Welfare, for the realization of a depth-of-interaction (DOI) detector
    Award ceremony: Recognized as a Person of Collaboration Merits by the Minister of Health, Labour and Welfare, for the realization of a depth-of-interaction (DOI) detector
  • Awarded the Science and Technology Prize by the Minister of Education, Culture, Sports, Science and Technology, for research on OpenPET
    Award ceremony: Awarded the Science and Technology Prize by the Minister of Education, Culture, Sports, Science and Technology, for research on OpenPET
  • First prototyping of the novel concept “whole gamma imaging”
    The first prototype system of whole gamma imaging (WGI)

Imaging Physics Team (IPT) succeeded in developing a novel 4-layered DOI detector, which is a key technology to get any significant improvement in sensitivity while maintaining high spatial resolution. IPT expanded PET application fields by making full use of DOI detectors. IPT invented the world’s first, open-type PET geometry "OpenPET", which is expected to lead to PET imaging during treatment. In addition to continuing work for on-going projects (OpenPET, helmet-type PET and add-on PET for MRI), IPT has started a new development project for a whole gamma imager (WGI), which is a new concept to combine PET and Compton imaging. Both DOI and OpenPET are long-term research projects which were started in 2000 and 2007, respectively. These awards, which celebrate the fruits of our labor, remind us to plant new seeds for the next generation research.

Project

Over view

PET innovation to be made by original ideas and technologies

The first midterm plan of NIRS (2001-2005)

IPT succeeded in developing a novel 4-layered DOI detector, which is a key technology to get any significant improvement in sensitivity while maintaining high spatial resolution. This DOI detector is the base for Shimadzu’s new line of positron emission mammography products.

The second midterm plan of NIRS (2006-2010)

IPT expanded PET application fields by making full use of DOI detectors. IPT invented the world’s first, open-type PET geometry OpenPET, which is expected to lead to PET imaging during treatment. The DOI detector itself evolved through application of recently developed semiconductor photodetectors, i.e., silicon photomultipliers (SiPMs). We developed a SiPM-based DOI detector X’tal cube to achieve the theoretical limitation of PET imaging resolution.

The third midterm plan of NIRS (2011-2015)

IPT made big progress with these technologies. In the OpenPET project, which received the German Innovation Award in 2012, IPT finally developed a full-scale OpenPET prototype. In addition, the flexible detector system of the OpenPET prototype enabled realization of an innovative brain scanner; this is the helmet-chin PET, which is now being commercialized in collaboration with ATOX Co., Ltd. On the other hand, technologies developed for the X’tal cube enabled a new idea of add-on PET, which can be applied to any existing MR systems in theory.

Since April 2016

NIRS has reorganized as part of the new organization, the National Institutes for Quantum and Radiological Science and Technology (QST). In addition to continuing work for these three on-going projects (OpenPET, helmet-chin PET and add-on PET), IPT has started a new development project for a whole gamma imager (WGI), which is a new concept to combine PET and Compton imaging.

  • OpenPET

    OpenPETプロジェクト

    OpenPET is our original idea to realize the world’s first open-type 3D PET scanner for PET-image guided particle therapy such as in situ dose verification and direct tumor tracking. The principal of dose verification for particle therapy is based on the measurement of positron emitters which are produced through fragmentation reactions caused by proton or 12C ion irradiation. Even with a full-ring geometry, the OpenPET has an open gap through which the treatment beam passes. In 2016, IPT showed that the difference between a PET peak position and a dose peak position could be smaller than 1 mm with the newly established 15O beam irradiation.

    In 2017, IPT continued its international collaboration. Outstanding HIMAC experiments which made full use of the potential of the OpenPET system were done. A PET-dose conversion method not only for RI beams but also for stable (12C etc.) beams was studied in collaboration with Ludwig-Maximilians-Universität München. Validation of Monte Carlo codes was investigated in collaboration with Australian Nuclear Science and Technology Organisation (ANSTO) / University of Wollongong. These results were presented at IEEE MIC 2017 as oral presentations, which were demonstrating the high quality and impact of these works.

    Brain dedicated helmet-type PET

    Brain dedicated helmet-type PET project

    Life extension is now causing another issue of rising numbers of dementia cases. To satisfy the potential demand for brain imaging, prototypes of brain PET scanners have been developed. However, all previous prototypes were based on a cylindrical geometry, which is not the most efficient for brain imaging. Making the detector ring as small as possible is essential in PET, because sensitivity can be increased with a limited number of detectors. Therefore, IPT developed the world’s first helmet-chin PET, in which DOI detectors are arranged to form a hemisphere, for compact, high-sensitivity, high-resolution, and low-cost brain PET imaging.

    In 2017, progressing towards a more patient-friendly system, we moved the chin detector unit to the back of the neck position. This change was based on our simulation, which showed that the effect of additional detectors depends on the number of detectors and does not depend significantly on their position. In practice, a 7% improvement in sensitivity was obtained because the safety margin, which was required for the chin-detectors, could be removed for the neck detectors.

    Add-on PET for MRI

    Add-on PET (PET/MRI) project

    One of the major innovations made in recent years is the combined PET/MRI, but utilization of DOI detectors has not been studied well. DOI measurements are essential for PET in order to exploit the improved spatial resolution and sensitivity as well as reduced production costs. Therefore, we proposed an add-on PET, which is a RF coil combined with DOI-PET detectors.

    In order to make the PET detector ring as small as possible while placing electronic parts such as photodetectors and front-end circuits outside the RF coil, PET detector modules were placed between spokes of the birdcage RF coil. For each detector module, electronic parts were covered with a shielding box with a hole in front of the photodetectors, and scintillators were stuck out of the shielding box to allow their placement inside the birdcage coil. In theory, the proposed birdcage coil integrated with PET detectors can be applied to any existing MRI.

    Following the development of a head-sized prototype in 2016, an oval detector arrangement was investigated, in particular we focused on the RF transmission performance, for the potential extension to whole-body PET/MRI imaging.

    Whole Gamma Imaging (WGI)

    WGI prototype

    PET is recognized as a successful imaging method, but in order to meet emerging demands such as in-situ single-level cell tracking, we need to break through an inherent limitation in the principle of PET itself. Therefore, in collaboration with Prof. Katia Parodi at Ludwig-Maximilians-Universität München and others, with support by the NIRS International Open Laboratory program and the QST President Grant, IPT started realization of the new concept of whole gamma imaging (WGI) in 2016.

    WGI is a concept utilizing all detectable gamma rays for imaging by combining PET and Compton imaging. An additional detector ring, which is used as the scatterer, is inserted in a conventional PET ring so that single gamma rays can be detected by the Compton imaging method. As a wide range of radioisotopes can be visualized, WGI is expected to enable imaging of the targeted radioisotope therapy. In addition, triple gamma emitters such as 44Sc, that emits a pair of 511 keV photons and a 1157 keV gamma ray almost at the same time, are selected as an imaging target. In theory, localization from a single decay is possible by identifying the intersection point between a coincidence line and a Compton cone.

    In 2017, following the simulation we accomplished in 2016, we succeeded in prototyping the first WGI system and showed a proof-of-concept of WGI, by visualizing a 44Sc source generated by the Department of Radiopharmaceuticals Development at NIRS. We showed the localization accuracy of the 12.7mm FWHM which was obtained as the intersection point between a coincidence line and a Compton cone. Further improvement will be possible by optimizing the detectors.

Member

Taiga Yamaya

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Team Leader

Eiji Yoshida

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Principal Researcher

Naoko Inadama

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Principal Resesarcher

Miwako Takahashi

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Principal Researcher

Fumihiko Nishikido

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Senior Researcher

Hideaki Tashima

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Senior Researcher

Md Shahadat Hossain Akram

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Senior Researcher

Hidekatsu Wakizaka

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Senior Technical Staff

Mohammadi Akram

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Researcher

Yuma Iwao

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Researcher

Kang Han Gyu

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Resaercher

Go Akamatsu

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Postdoctoral Researcher

Sodai Takyu

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Postdoctoral Researcher

Fujino Obata

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Technical Staff

Madoka Ohno

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Secretary

Masumi Tanaka

Imaging Physics Group, Department of Nuclear Medicine Science, National Institute of Radiological Sciences
Secretary

Achievement

# Peer-reviewed articles Year
Hideaki Tashima, Eiji Yoshida, Yuma Iwao, Hidekatsu Wakizaka, Takamasa Maeda, Chie Seki, Yasuyuki Kimura, Yuhei Takado, Makoto Higuchi, Tetsuya Suhara, Taichi Yamashita and Taiga Yamaya, “First prototyping of a dedicated PET system with the hemisphere detector arrangement,” Phys. Med. Biol., vol. 64, no. 6, p. 065004, Jan. 2019. 2019
Akram Mohammadi, Eiji Yoshida, Fumihiko Nishikido, Munetaka Nitta, Keiji Shimizu, Toshiaki Sakai, Taiga Yamaya, “Development of a dual-ended readout detector with segmented crystal bars made using a subsurface laser engraving technique,” Physics in Medicine and Biology, Volume 63, Number 2, 025019, 2018. 2018
Chie Toramatsu, Eiji Yoshida, Hidekazu Wakizaka, Akram Mohammadi, Yoko Ikoma, Hideaki Tashima, Fumihiko Nishikido, Atsushi Kitagawa, Kumiko Karasawa, Yoshiyuki Hirano, Taiga Yamaya, “Washout effect in rabbit brain: in-beam PET measurements using 10C, 11C and 15O ion beams” Biomed. Phys. Eng. Express, 4, 035001, 2018. (Appeared in MedicalPhysicsWeb: http://medicalphysicsweb.org/cws/article/research/71337) 2018
Yukie Yoshii, Mitsuyoshi Yoshimoto, Hiroki Matsumoto, Hideaki Tashima, Yuma Iwao, Hiroyuki Takuwa, Eiji Yoshida, Hidekatsu Wakizaka, Taiga Yamaya, Ming-Rong Zhang, Aya Sugyo, Sayaka Hanadate, Atsushi B. Tsuji, Tatsuya Higashi, "Integrated treatment using intraperitoneal radioimmunotherapy and positron emission tomography-guided surgery with 64Culabeled cetuximab to treat early- and late-phase peritoneal dissemination in human gastrointestinal cancer xenografts," Oncotarget, Vol. 9, No. 48, pp. 28935-28950, 2018. 2018
Md Shahadat Hossain Akram, Craig S. Levin, Takayuki Obata, Genki Hirumi, Taiga Yamaya, "Geometry optimization of electrically floating PET inserts for improved RF penetration for a 3 T MRI system," Med. Phys., 45 (10), pp. 4627-4641, 2018. 2018
R. S. Augusto, A. Mohammadi, H. Tashima, E. Yoshida, T. Yamaya, A. Ferrari, K. Parodi, "Experimental validation of the FLUKA Monte Carlo code for dose and β+–emitter predictions of radioactive ion beams," Phys. Med. Biol., 63, 215014, 2018. 2018
Munetaka Nitta , Naoko Inadama , Fumihiko Nishikido, Eiji Yoshida , Hideaki Tashima, Hideyuki Kawai, Taiga Yamaya, "Development of the X'tal cube PET detector with segments of (0.77mm)3" IEEE Transactions on Radiation and Plasma Medical Sciences, Vol. 2, No. 6, pp. 564-573, 2018. 2018
Yuji Tsutsui, Hiromitsu Daisaki, Go Akamatsu, Takuro Umeda, Matsuyoshi Ogawa, Hironori Kajiwara, Shigeto Kawase, Minoru Sakurai, Hiroyuki Nishida, Keiichi Magota, Kazuaki Mori, Masayuki Sasaki, J-Hart study group, “Multicentre analysis of PET SUV using vendor-neutral software: the Japanese Harmonization Technology (J-Hart) study,” EJNMMI Research (2018) 8:83. 2018
Akram Mohammadi, Eiji Yoshida, Hideaki Tashima, Fumihiko Nishikido, Taku Inaniwa, Atsushi Kitagawa, Taiga Yamaya, "Production of an 15O beam using a stable oxygen ion beam for in-beam PET imaging," Nuclear Instruments and Methods in Physics Research A 849, pp. 76–82 2017
Abdella M. Ahmed, Hideaki Tashima, Eiji Yoshida, Taiga Yamaya, " Investigation of the optimal detector arrangement for the helmet-chin PET – A simulation study," Nuclear Instruments and Methods in Physics Research A 858, pp. 96–100 2017
Abdella M Ahmed, Hideaki Tashim, Taiga Yamaya, "Simulation study of a D-shape PET scanner for improved sensitivity and reduced cost in whole-body imaging," Phys. Med. Biol., Vol., 62, pp. 4107-4117 2017
Abdella M Ahmed, Hideaki Tashima, Eiji Yoshida, Fumihiko Nishikido, Taiga Yamaya, “Simulation study comparing the helmet-chin PET with a cylindrical PET of the same number of detectors,” Phys. Med. Biol., vol. 62, pp. 4541-4550 2017
Akram Mohammadi, Naoko Inadama, Eiji Yoshida, Fumihiko Nishikido, Keiji Shimizu, Taiga Yamaya, "Improvement of crystal identification performance for a four-layer DOI detector composed of crystals segmented by laser processing," Nuclear Inst. and Methods in Physics Research, A 866, pp. 29–35 2017
F. Nishikido, M. Fujiwara, H. Tashima, M. S. H. Akram, M. Suga, T. Obata, T. Yamaya, "Development of a full-ring "add-on PET" prototype: A head coil with DOI-PET detectors for integrated PET/MRI," Nuclear Instruments and Methods in Physics Research, A 863, pp. 55–61 2017
Eiji Yoshida, Hideaki Tashima, Tetsuya Shinaji, Keiji Shimizu, Hidekatsu Wakizaka, Akram Mohammadi, Fumihiko Nishikido, Taiga Yamaya, "Development of a whole-body dual ring OpenPET for in-beam PET," IEEE Transactions on Radiation and Plasma Medical Sciences, Vol. 1, No. 4, pp. 293-300 2017
A. Koyama,H. Miyoshi, K. Shimazoe, Y. Otaka, M. Nitta, F. Nishikido, T. Yamaya, H. Takahashi, "Radiation stability of an InGaZnO thin-film transistor in heavy ion radiotherapy," Biomed. Phys. Eng. Express, 3, 045009 2017
Md Shahadat Hossain Akram, Takayuki Obata, Mikio Suga, Fumihiko Nishikido, Eiji Yoshida, Kazuyuki Saito, Taiga Yamaya, “MRI compatibility study of an integrated PET/RF-coil prototype system at 3 T,” Journal of Magnetic Resonance 283, pp. 62-70 2017
T. Inaniwa, H. Tashima, N. Kanematsu, “Optimum size of a calibration phantom for x-ray CT to convert the Hounsfield units to stopping power ratios in charged particle therapy treatment planning,” Journal of Radiation Research, pp. 1–9 2017
Abdella M. Ahmed, Hideaki Tashima, Taiga Yamaya, "Investigation of spatial resolution improvement by use of a mouth insert detector in the helmet PET scanner," Radiol. Phys. Technol. 2017
# Review articles Year
山谷泰賀(共同執筆), "生体計測分析技術・医療機器," 研究開発の俯瞰報告書 ライフサイエンス・臨床医学分野2017年, pp. 326-452 2017
山谷泰賀, "DOI検出器が切り拓く次世代のPET装置の研究開発," 放射線医学総合研究所創立60周年記念誌, pp. 16-17 2017
三輪建太,我妻慧,山尾天翔,上高祐人,松原佳亮,赤松剛,今林悦子,“アミロイドPETの定量評価に関する研究,” 日本放射線技術学会雑誌.Vol. 73, pp. 1165-1174 2017
# Book chapters Year
Taiga Yamaya, Hideaki Tashima, "OpenPET enabling PET imaging during radiotherapy," Book capter in Personalized Pathway-Activated Systems Imaging in Oncology: Principal and Instrumentation, Springer, pp. 55-84, 2017. 2017
山谷泰賀, "世界初の開放型PET装置の研究開発", 科学立国日本を築くpart II 次代を拓く気鋭の研究者たち, pp. 202-210, 2017 (日刊工業新聞社) 2017
# Press releases and news articles Year
千葉大学と量子科学技術研究開発機構との包括的連携協力に関する協定書の締結について, プレスリリース, 2017/2/2 http://www.qst.go.jp/information/itemid034-001721.html (翌日の千葉日報、日刊工業、日経産業に展示したOpenPET試作機とともに「がん治療技術 確立へ」などのヘッドラインで紹介) 2017
"画像見てがん除去 量研機構が取りこぼし防ぐシステム," 日刊工業新聞1面, 2017/3/21. 2017
放射線医学総合研究所の研究員が平成29年度文部科学大臣表彰科学技術賞を受賞しました, ニュースリリース, 2017/4/19 http://www.qst.go.jp/information/itemid047-002154.html 2017
“第113回日本医学物理学会学術大会のCyPos大会長賞と英語プレゼンテーション賞を受賞しました,” ニュースリリース, 2017/5/16 http://www.nirs.qst.go.jp/information/news_prize/2017/0516.html 2017
“乳房専用PET装置「Elmammo」の研究・開発で「産学官連携功労者表彰 厚生労働大臣賞」を受賞”ニュースリリース, 2017/8/21 http://www.qst.go.jp/information/itemid034-002617.html 2017
# Awards Year
山谷泰賀, 吉田英治, 田島英朗, "開放型PET装置の発明と粒子線がん治療可視化法の研究," 平成29年度科学技術分野の文部科学大臣表彰科学技術賞(研究部門)受賞 (2017/4/19). Taiga Yamaya, Eiji Yoshida, Hideaki Tashima, “Invention of an open-type PET instrumentation and research on visualization of particle therapy,” Awarded the Science and Technology Prize by the Minister of Education, Culture, Sports, Science and Technology, April 19, 2017. http://www.mext.go.jp/b_menu/houdou/29/04/1384228.htm http://www.qst.go.jp/information/itemid047-002154.html 2017
山谷泰賀, 中本裕士, 北村圭司, “乳房専用PET装置「Elmammo」の開発に係る産学官連携,” 第15回産学官連携功労者表彰 厚生労働大臣賞 受賞 (2017/9/1). Taiga Yamaya, Yuji Nakamoto, Keishi Kitamura, “Industry-academia-government collaboration for the development of a breast dedicated PET, Elmammo,” Recognized as a Person of Collaboration Merits by the Minister of Health, Labour and Welfare, September 1, 2017. http://www8.cao.go.jp/cstp/sangakukan/index2.html http://www.qst.go.jp/information/itemid034-002617.html 2017
錦戸文彦, "Development of second add‒on PET/MRI prototype: Evaluation of PET imaging performance," O‒043, 第113回日本医学物理学会学術大会 CyPos大会長賞 Fumihiko Nishikido, the CyPos General Chair Award by the 113th Scientific Meeting of the Japan Society of Medical Physics 2017
田島英朗, "Development of a small prototype system toward real‒time OpenPET image‒guided surgery," O‒54, 第113回日本医学物理学会学術大会 英語プレゼンテーション賞 Hideaki Tashima, the English Presentation Award by the 113th Scientific Meeting of the Japan Society of Medical Physics 2017
山谷泰賀, "Whole gamma imaging concept: feasibility study of triple‒gamma imaging," O‒38, 第113回日本医学物理学会学術大会 英語プレゼンテーション賞 Taiga Yamaya, the English Presentation Award by the 113th Scientific Meeting of the Japan Society of Medical Physics http://www.jsmp.org/conf/113/e_presentation.html http://www.nirs.qst.go.jp/information/news_prize/2017/0516.html 2017
Md Shahadat Hossain Akram, Awarded to “ISMRM Summa Cum Laude Merit Award” for his presentation “Development and performance evaluation of the second prototype of a RF-coil integrated PET insert for existing 3T MRI systems,” (Given to Trainee Members whose abstracts score in the top 5% within a major subject review category) http://www.nirs.qst.go.jp/information/news_prize/2017/0602.html 2017
Md Shahadat Hossain Akram, IEEE NSS-MIC 2017 Trainee Grant ($500). 2017
Paper listed in “PMB Highlights in 2016” http://iopscience.iop.org/journal/0031-9155/page/Highlights_of_2016 Hideaki Tashima, …, Taiga Yamaya, "Development of a small single-ring OpenPET prototype with a novel transformable architecture," Phys. Med. Biol., Vol. 61, pp. 1795-1809, 2016 2017