著者

平岡 武

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.21, no.2, pp.81-85, 2001-06-30 (Released:2012-09-24)

参考文献数

4

著者

磯辺 智範 山本 哲哉 阿久 津博義 佐藤 英介 只野 喜一 増本 智彦 榮 武二 松村 明

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.36, no.2, pp.85-91, 2016-08-31 (Released:2017-02-02)

参考文献数

14

被引用文献数

1

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1H-MRS (proton magnetic resonance spectroscopy) is a method for analyzing material components using the difference of the frequency (chemical shift) in magnetic resonance. 1H-MRS for human body is able to diagnose the clinical conditions by non-invasive analysis of materials in organs. However, the mechanical limitations and complexity in analyses prevented it from becoming popular as MRI (magnetic resonance imaging). Recently, an ideal environment for 1H-MRS is commonly available such as stronger magnetic field and improved software, yet we still lack common knowledges about 1H-MRS which makes whom plans to start it difficult. In this article, the principle, tips, clinical applications and spectrum evaluations were explained focusing on novice users.

著者

伊良皆 拓 金城 優志 田中 創大 恒田 雅人 平島 英明

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.42, no.2, pp.88-105, 2022-06-30 (Released:2022-06-30)

参考文献数

9

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Details of Young Researchers’ Association of Medical Physics (YRAMP) was introduced. In addition, several questionnaire surveys on medical physics education (MPE) or medical physicist training system (MPTS) in Japan have been conducted, none have targeted the current status and issues of MPE and MPTS. The purpose of this study was to investigate those from the perspective of researchers and students under 35-year-old (y.o.). The questionnaire survey was conducted between 14th September to 14th October 2021, for 112 members of the Young Researchers’ Association of Medical Physics via Google Forms. The questionnaire was in two parts: MPE (Part1) and MPTS (Part2). Three subparts were constructed in Part1: Classroom lecture, Clinical training, Education course accredited by Japanese Board of Medical Physicist Qualification. Out of a total of 126 questions, 38 were mandatory to be answered. No personal information was collected. Ninety-three members (83.0%) were answered. The age structure of the respondents was as follows: 18–21, 22–26, 27–30, and 31–35 y.o.=5.4%, 36.6%, 39.8%, and 18.2%. Of the respondents, 74.2% and 11.8% answered that they first heard of “medical physics” or “medical physicist” when they were undergraduate students and in high school or younger, respectively. In Classroom lecture, 61.3%, 17.2%, and 21.5% of the respondents answered that they were “satisfied” or “moderately satisfied”, “dissatisfied” or “moderately dissatisfied”, and “Not sure” with the current MPE, respectively. In Clinical training, Education course, and MPTS, 58.1%, 21.5%, and 20.4% of the respondents answered that they were “satisfied” or “moderately satisfied”, “dissatisfied” or “moderately dissatisfied”, and “Not sure”, respectively. In both MPE and MPTS, approximately 88% and 51% of the respondents answered that “holding lectures and study sessions for high school and undergraduate students” and “utilizing YouTube” would be useful in promoting MPE and MPTS in Japan, respectively. The results of the questionnaire survey will provide useful data for MPE and MPTS in Japan.

著者

谷 謙甫 脇田 明尚

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.40, no.3, pp.88-96, 2020-09-30 (Released:2020-09-30)

参考文献数

19

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The quality assurance (QA) of the output constancy of linear accelerators (linacs) is one of the most basic items for radiation therapy. The necessity and demand of the dosimetric audit is on the rise. We aimed at establishing an on-site dosimetric audit program with a plastic phantom in order to enrich the availability of dosimetric audit in Japan. By this, we developed and evaluated an on-site audit program in multiple institutions in 120 cases for photon and electron standard dosimetry and intensity modulated radiation therapy (IMRT) condition. For photon standard dosimetry, we evaluated the accuracies of institutional measured absorbed dose in 50 cases by this on-site audit program. For the electron standard dosimetry, we evaluated the accuracies of institutional measured absorbed dose in 25 cases. For IMRT condition, we evaluated the accuracies of the institutional calculated dose in radiation treatment planning systems in 45 cases. The agreements of the measured absorbed dose between our audit and the institutions were within±1.1% for photon standard dosimetry. The agreements of the measured absorbed dose between our audit and the institutions were within±2.1% for electron standard dosimetry. The agreements between the measured absorbed dose of our audit and the institutional calculated dose were within±2.1% for IMRT condition. We established an on-site dosimetric audit program with a plastic phantom and this program is suitable with tight criteria similar to criteria required for clinical QA.

著者

遠山 尚紀 岡本 裕之 黒岡 将彦 木藤 哲史 株木 重人 古徳 純一 福士 政広 大野 達也 唐澤 久美子

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.42, no.3, pp.123-142, 2022-09-30 (Released:2022-09-30)

参考文献数

2

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The questionnaire survey was conducted in 2020 to investigate the working conditions of qualified medical physicists in Japan. We developed a web-based system for administering the questionnaire and surveyed 1,228 qualified medical physicists. The number of received responses was 405. We summarized the results of the survey by job category. The obtained results showed that most of the people working as certified medical physicists met the following conditions: (1) position of healthcare occupation, (2) direct supervisor is a medical doctor or a medical physicist, (3) licensed or passed an examination for a Class I Radiation Protection Supervisor, (4) without the license of professional radiotherapy technologist, (5) master’s or doctor’s degree, (6) being assigned to the section that is different from the radiological technologist section. The average annual salary was approximately 600,000 yen higher for those employed as medical physicists than for those employed as radiotherapy technologists. The percentage of work performed by a certified medical physicist in radiation therapy greatly varies depending on whether the physicist is dedicated to treatment planning and equipment quality control. Alternatively, the proportion of the true duties of medical physicists in charge of radiation therapy, as considered by qualified medical physicists in radiation therapy, was the same regardless of whether they were working full-time or not. The results of this survey updated the working status of certified medical physicists in Japan. We will continue to conduct the survey periodically and update the information to contribute to the improvement of the working conditions of medical physicists and policy recommendations.

著者

松原 佳亮 茨木 正信 志田原 美保 木下 俊文

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.43, no.1, pp.20, 2023-04-12 (Released:2023-04-12)

参考文献数

1

著者

古徳 純一

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.40, no.2, pp.55-60, 2020-06-30 (Released:2020-06-30)

参考文献数

3

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This manuscript is a supplement to the machine learning course at JSMP Medical Physics Summer School held in 2019. The idea of Kulbuck-Leibler divergence, a key concept in machine learning, is introduced with mutual information.

著者

遠藤 真広

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.41, no.1, pp.10-21, 2021-03-31 (Released:2021-04-14)

参考文献数

29

著者

笠井 咲

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.37, no.4, pp.216-219, 2017 (Released:2018-03-08)

参考文献数

2

著者

馬込 大貴 藤田 幸男 保科 正夫 佐藤 昌憲

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.40, no.2, pp.68-70, 2020-06-30 (Released:2020-06-30)

参考文献数

5

著者

遠藤 真広

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.40, no.2, pp.61-67, 2020-06-30 (Released:2020-06-30)

参考文献数

9

著者

宇都宮 悟 和田 真一

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.40, no.2, pp.46-50, 2020-06-30 (Released:2020-06-30)

参考文献数

15

著者

河内 徹 片寄 哲朗

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.33, no.4, pp.186-191, 2013 (Released:2015-02-19)

参考文献数

16

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This report describes the update of the beam quality conversion factor KQ,Q0 of the standard dosimetry protocol in Japan. The KQ,Q0 corrects for the difference between the response of an ionization chamber in the reference beam quality Q0 used for calibrating the chamber and in the actual user beam quality Q. All changes of KQ,Q0 were caused by the perturbation correction factors which were recalculated by Monte Carlo simulation. With a calculation process, unsolved problems in this update are also discussed here.

著者

塚越 伸介 信藤 康孝 立崎 寿

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.41, no.3, pp.96-102, 2021-09-30 (Released:2021-11-05)

参考文献数

28

著者

平井 奈々子 佐藤 清香

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.36, no.3, pp.137-147, 2016 (Released:2017-04-24)

参考文献数

97

著者

村瀬 研也

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.36, no.1, pp.55-61, 2016-05-31 (Released:2016-11-30)

参考文献数

16

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Partial differential equations are often used in the field of medical physics. In this (final) issue, the methods for solving the partial differential equations were introduced, which include separation of variables, integral transform (Fourier and Fourier-sine transforms), Green's function, and series expansion methods. Some examples were also introduced, in which the integral transform and Green's function methods were applied to solving Pennes' bioheat transfer equation and the Fourier series expansion method was applied to Navier-Stokes equation for analyzing the wall shear stress in blood vessels.Finally, the author hopes that this series will be helpful for people who engage in medical physics.

著者

佐藤 英介 磯辺 智範 山本 哲哉 松村 明

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.36, no.2, pp.97-102, 2016-08-31 (Released:2017-02-02)

参考文献数

11

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The magnetic resonance imaging (MRI) is established as the imaging technique that is essential to the imaging of the central nervous system disease. Above all, the diffusion weighted image (DWI) is known as the tool which can diagnose acute ischemic stroke with high accuracy in a short time. DTI, an applied form of DWI, was devised as a technique to image the structure of the brain white matter. In clinical sites, this technique is used for pathologic elucidation such as the intracerebral tissue injury or mental disorder. Additionally, diffusion tensor tractography (DTT), which is a technique to build three-dimensional structure of the neural fiber tracts, is used for grasping the relations between a brain tumor and the fibers tract. Therefore, these techniques may be useful imaging tools in the central nerve region.

著者

遠藤 真広

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.37, no.1, pp.47-53, 2017-07-31 (Released:2017-09-15)

被引用文献数

2

著者

橋本 慎太郎 仁井田 浩二 松田 規宏 岩元 洋介 岩瀬 広 佐藤 達彦 野田 秀作 小川 達彦 中島 宏 深堀 智生 古田 琢哉 千葉 敏

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.33, no.2, pp.88-95, 2013 (Released:2014-10-21)

参考文献数

32

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PHITS is a general purpose Monte Carlo particle transport simulation code to analyze the transport in three-dimensional phase space and collisions of nearly all particles, including heavy ions, over wide energy range up to 100 GeV/u. Various quantities, such as particle fluence and deposition energies in materials, can be deduced using estimator functions “tally”. Recently, a microdosimetric tally function was also developed to apply PHITS to medical physics. Owing to these features, PHITS has been used for medical applications, such as radiation therapy and protection.

著者

福田 茂一

出版者

公益社団法人 日本医学物理学会

雑誌

医学物理 (ISSN:13455354)

巻号頁・発行日

vol.40, no.3, pp.73, 2020-09-30 (Released:2020-09-30)