Study on the effective energy measurement method required for high accuracy absorbed dose evaluation of the CT apparatus

2017 Fiscal Year Annual Research Report

• Project/Area Number: 16K21553
• Research Institution: Kawasaki University of Medical Welfare
• Principal Investigator: 五反田 龍宏 川崎医療福祉大学, 医療技術学部, 准教授 (60711447)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 実効エネルギー / X線CT / 線量計測用フィルム / GAFCHROMIC Film / スキャナ特性

Outline of Annual Research Achievements

我が国は世界と比べてX線コンピューテッドトモグラフィ（CT）装置の普及率が高く，医療被曝が高い傾向にある．医療被曝を正確に評価するためには，X線束の線質を定期的に測定することによってCT装置のQA，QCを行うことが重要である．本研究では，いかなる施設においてもCT装置の線質評価を簡易的かつ安価に評価する方法を開発することを目的としている．
初年度は，実験に適した線量計測用フィルムの選択とそのフィルムの画像を取得するためのスキャナの選択および特性を評価した．結果として，最もエネルギー依存性の低いGAFCHROMIC EBT3（EBT3）が実効エネルギー特性の評価に優れていることが実証された．また，モバイルスキャナと平台型スキャナの比較から，平台型スキャナが再現性に最も優れていることが実証されたが，スキャン時の経時的な変化による影響があることが観察された．そのため，スキャナの経時的特性の評価を行い，スキャナの電源投入後5時間以降かつ連続スキャン3回目のデータを使用することが最も高精度に計測できることが実証された．
最終年度は，EBT3を使用してCT装置（320列）のX線束中心のみの実効エネルギー計測法と，X線束全域の実効エネルギー計測法を検討した．結果として，アルミニウム半価層は9.14 mmとなり，実効エネルギーは58.4 keVとなった．誤差5％以下の精度で簡易的に計測できることが実証された．
次に，CT装置（320列）のX線束全域の実効エネルギーの分布を計測した．全照射領域の半分を計測対象とし，45区画に分けて計測した．結果として，実効エネルギーは，寝台と平行方向での影響は少なかったが，寝台と垂直方向では中央から側方に行くほど高くなった．本研究では，実効エネルギーの2次元分布評価ならびに簡易的計測が可能であることが実証された．

Research Products

• [Journal Article] Evaluation of effective energy distribution of 320-multidetector CT using GAFCHROMIC EBT3 (2018)
  • Author(s): Tatsuhiro Gotanda, Toshizo Katsuda, Rumi Gotanda, Takuya Akagawa, Tadao Kuwano, Nobuyoshi Tanki, Hidetoshi Yatake, Yasuyuki Kawaji, Takashi Amano, Shinichi Arao, Atsushi Ono, Akihiko Tabuchi
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Influence of image resolution property on aliasing error of digital wiener spectrum (2018)
  • Author(s): Yasuyuki Kawaji, Tatsuhiro Gotanda, Tetsunori Shimono, Nobuyoshi Tanki, Toshizo Katsuda, Rumi Gotanda, Tadao Kuwano, Takuya Akagawa
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Temporal characterization of the flat-bed scanner influencing dosimetry using radiochromic film (2018)
  • Author(s): Rumi Gotanda, Toshizo Katsuda, Tatsuhiro Gotanda, Nobuyoshi Tanki, Hidetoshi Yatake, Yasuyuki Kawaji, Tadao Kuwano, Takuya Akagawa, Akihiko Tabuchi, Atsushi Ono, Shinichi Arao
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Accurately evaluating settling responses of ionization chambers used in radiation therapy depend on the accelerating tube (2018)
  • Author(s): Tetsunori Shimono, Yasuyuki Kawaji, Tatsuhiro Gotanda, Rumi Gotanda, Hiroshi Okuda
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Effect of Weight Input in Magnetic Resonance Imaging System on Radio-Frequency-Induced Heating of Metallic Implants (2018)
  • Author(s): Atsushi Ono, Shinichi Arao, Satoru Takata, Tatsuhiro Gotanda, Rumi Gotanda, Akihiko Tabuchi
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Optimal Variable Refocus Flip Angle Control Method and Echo Train Length for Suppressing Exposure to Radio Frequency (2018)
  • Author(s): Akihiko Tabuchi, Shinichi Arao, Toshizo Katsuda, Atsushi Ono, Tatsuhiro Gotanda, Rumi Gotanda
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Basic study of the imaging conditions on tumor volume measurement using 3D-MR imaging of the liver while patient holds breath (2018)
  • Author(s): Shinichi Arao, Akihiko Tabuchi, Yasuhiko Okura, Hajime Harauchi, Atsushi Ono, Tatsuhiro Gotanda, Rumi Gotanda, Akiko Hayashi
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Size and shape of spherical objects on full-field digital mammography and digital breast tomosynthesis images (2018)
  • Author(s): Hidetoshi Yatake, Yuka Sawai, Takahiro Kozuka, Yoshihiro Takeda, Mariko Kajihara, Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Shuji Abe, Makoto Shimada, Nobuyoshi Tanki, Toshio Nishi, Hideo Inaji
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 68 Pages: -
  • Peer Reviewed
• [Journal Article] Determining optimum wavelength of ultraviolet rays to pre-exposure of non-uniformity error correction in Gafchromic EBT2 films (2018)
  • Author(s): Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Nobuyoshi Tanki, Tadao Kuwano, Atsushi Noguchi, Kouichi Yabunaka
  • Journal Title: Polish Journal of Medical Physics and Engineering Volume: 24(1) Pages: 11-14
  • DOI: https://doi.org/10.2478/pjmpe-2018-0002
  • Peer Reviewed / Open Access
• [Journal Article] Influence of scattered radiation on Gafchromic EBT3 (2017)
  • Author(s): Tatsuhiro Gotanda, Toshizo Katsuda, Ayano Kawasaki, Rumi Gotanda, Takuya Akagawa, Tadao Kuwano, Nobuyoshi Tanki, Yasuyuki Kawaji, Tetsunori Shimono, Kenyu Yamamoto, Koichi Yabunaka
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 65 Pages: 1037-1040
  • DOI: https://doi.org/10.1007/978-981-10-5122-7_101
  • Peer Reviewed
• [Journal Article] Intensities of incident and transmitted ultraviolet-a rays through gafchromic films (2017)
  • Author(s): Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Nobuyoshi Tanki, Tadao Kuwano, Atsushi Noguchi, Kouichi Yabunaka
  • Journal Title: Journal of Medical Physics Volume: 42(2) Pages: 86-89
  • DOI: https://doi.org/10.4103/jmp.JMP_136_16
  • Peer Reviewed
• [Journal Article] Ultraviolet Ray Strength for Pre-irradiation in Gafchromic EBT2 (2017)
  • Author(s): Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Atsushi Noguchi, Nobuyoshi Tanki, Tadao Kuwano, Kouichi Yabunaka
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 65 Pages: 386-389
  • DOI: https://doi.org/10.1007/978-981-10-5122-7_97
  • Peer Reviewed
• [Journal Article] UV Intensity of Pre-irradiation in Gafchromic XR-RV3 and XR-SP2 (2017)
  • Author(s): Tadao Kuwano, Yoshihiro Takeda, Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Nobuyoshi Tanki, Atsushi Noguchi, Yasuyuki Kawaji, Kenyu Yamamoto, Koichi Yabunaka
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 65 Pages: 53-56
  • DOI: https://doi.org/10.1007/978-981-10-5122-7_14
  • Peer Reviewed
• [Journal Article] Basic research on countermeasures against barium sulfate aggregation using a gastric phantom (2017)
  • Author(s): Kenyu Yamamoto, Naoko Fujiwara, Yoshihiro Takeda, Rena Takakura, Tetsushi Ishida, Toshizo Katsuda, Tadao Kuwano, Misao Yoneda, Tatsuhiro Gotanda, Shuji Abe, Makoto Shimada, Masami Azuma, Sachiko Tanaka
  • Journal Title: International Fedration Medical and Biological Engineering Proceedings Volume: 65 Pages: 675-678
  • DOI: https://doi.org/10.1007/978-981-10-5122-7_169
  • Peer Reviewed
• [Presentation] Evaluation of effective energy distribution of 320-multidetector CT using GAFCHROMIC EBT3 (2018)
  • Author(s): Tatsuhiro Gotanda, Toshizo Katsuda, Rumi Gotanda, Takuya Akagawa, Tadao Kuwano, Nobuyoshi Tanki, Hidetoshi Yatake, Yasuyuki Kawaji, Takashi Amano, Shinichi Arao, Atsushi Ono, Akihiko Tabuchi
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Comparison of UV-A sensitivity exposed from front side and backside in Gafchromic XR-RV3: preliminary study (2018)
  • Author(s): Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Nobuyoshi Tanki, Atsushi Noguchi, Tadao Kuwano, Shinya Imai, Kouichi Yabunaka
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Temporal characterization of the flat-bed scanner influencing dosimetry using radiochromic film (2018)
  • Author(s): Rumi Gotanda, Toshizo Katsuda, Tatsuhiro Gotanda, Nobuyoshi Tanki, Hidetoshi Yatake, Yasuyuki Kawaji, Tadao Kuwano, Takuya Akagawa, Akihiko Tabuchi, Atsushi Ono, Shinichi Arao
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Efficient X-ray CT dosimetry procedure using radiochromic film and film-folding type phantom (2018)
  • Author(s): Nobuyoshi Tanki, Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Hidetoshi Yatake, Yasuyuki Kawaji, Hideki Fujita, Atsushi Noguchi, Tadao Kuwano, Shinya Imai, Takuya Akagawa, Yoshihiro Takeda
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Influence of image resolution property on aliasing error of digital wiener spectrum (2018)
  • Author(s): Yasuyuki Kawaji, Tatsuhiro Gotanda, Tetsunori Shimono, Nobuyoshi Tanki, Toshizo Katsuda, Rumi Gotanda, Tadao Kuwano, Takuya Akagawa
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Accurately evaluating settling responses of ionization chambers used in radiation therapy depend on the accelerating tube (2018)
  • Author(s): Tetsunori Shimono, Yasuyuki Kawaji, Tatsuhiro Gotanda, Rumi Gotanda, Hiroshi Okuda
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Optimal Variable Refocus Flip Angle Control Method and Echo Train Length for Suppressing Exposure to Radio Frequency (2018)
  • Author(s): Akihiko Tabuchi, Shinichi Arao, Toshizo Katsuda, Atsushi Ono, Tatsuhiro Gotanda, Rumi Gotanda
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Effect of Weight Input in Magnetic Resonance Imaging System on Radio-Frequency-Induced Heating of Metallic Implants (2018)
  • Author(s): Atsushi Ono, Shinichi Arao, Satoru Takata, Tatsuhiro Gotanda, Rumi Gotanda, Akihiko Tabuchi
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Basic study of the imaging conditions on tumor volume measurement using 3D-MR imaging of the liver while patient holds breath (2018)
  • Author(s): Shinichi Arao, Akihiko Tabuchi, Yasuhiko Okura, Hajime Harauchi, Atsushi Ono, Tatsuhiro Gotanda, Rumi Gotanda, Akiko Hayashi
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Size and shape of spherical objects on full-field digital mammography and digital breast tomosynthesis images (2018)
  • Author(s): Hidetoshi Yatake, Yuka Sawai, Takahiro Kozuka, Yoshihiro Takeda, Mariko Kajihara, Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Shuji Abe, Makoto Shimada, Nobuyoshi Tanki, Toshio Nishi, Hideo Inaji
  • Organizer: World Congress on Medical Physics & Biomedical Engineering
  • Int'l Joint Research
• [Presentation] Development of ultraviolet ray irradiation device for Gafchromic XR-SP2 films (2018)
  • Author(s): Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, A Sasaki, Takuya Akagawa, Nobuyoshi Tanki, Atsushi Noguchi, Tadao Kuwano, Koichi Yabunaka
  • Organizer: European Congress of Radiology 2018
  • Int'l Joint Research
• [Presentation] Influence of scattered radiation on Gafchromic EBT3 (2017)
  • Author(s): Tatsuhiro Gotanda, Toshizo Katsuda, Ayano Kawasaki, Rumi Gotanda, Takuya Akagawa, Tadao Kuwano, Nobuyoshi Tanki, Yasuyuki Kawaji, Tetsunori Shimono, Kenyu Yamamoto, Koichi Yabunaka
  • Organizer: The joint conference of the European Medical and Biological Engineering Conference (EMBEC) and the Nordic-Baltic Conference on Biomedical Engineering (NBC)
  • Int'l Joint Research
• [Presentation] Ultraviolet Ray Strength for Pre-irradiation in Gafchromic EBT2 (2017)
  • Author(s): Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Atsushi Noguchi, Nobuyoshi Tanki, Tadao Kuwano, Kouichi Yabunaka
  • Organizer: The joint conference of the European Medical and Biological Engineering Conference (EMBEC) and the Nordic-Baltic Conference on Biomedical Engineering (NBC)
  • Int'l Joint Research
• [Presentation] UV Intensity of Pre-irradiation in Gafchromic XR-RV3 and XR-SP2 (2017)
  • Author(s): Tadao Kuwano, Yoshihiro Takeda, Toshizo Katsuda, Rumi Gotanda, Tatsuhiro Gotanda, Takuya Akagawa, Nobuyoshi Tanki, Atsushi Noguchi, Yasuyuki Kawaji, Kenyu Yamamoto, Koichi Yabunaka
  • Organizer: The joint conference of the European Medical and Biological Engineering Conference (EMBEC) and the Nordic-Baltic Conference on Biomedical Engineering (NBC)
  • Int'l Joint Research
• [Presentation] Basic research on countermeasures against barium sulfate aggregation using a gastric phantom (2017)
  • Author(s): Kenyu Yamamoto, Naoko Fujiwara, Yoshihiro Takeda, Rena Takakura, Tetsushi Ishida, Toshizo Katsuda, Tadao Kuwano, Misao Yoneda, Tatsuhiro Gotanda, Shuji Abe, Makoto Shimada, Masami Azuma, Sschiko Tanaka
  • Organizer: The joint conference of the European Medical and Biological Engineering Conference (EMBEC) and the Nordic-Baltic Conference on Biomedical Engineering (NBC)
  • Int'l Joint Research
• [Presentation] Response characteristics of radiochromic film at CT radiation quality (2017)
  • Author(s): Rumi Gotanda, Hitoshi Sato, Erika Nakajima, Kumi Sano, Saki Osumi, Tatsuhiro Gotanda, Takuya Akagawa, Tadao Kuwano, Nobuyoshi Tanki, Toshizo Katsuda
  • Organizer: The joint conference of the European Medical and Biological Engineering Conference (EMBEC) and the Nordic-Baltic Conference on Biomedical Engineering (NBC)
  • Int'l Joint Research