Dept. of Radiation Measurement and Dose Assessment


 The radiation measurement, imaging and dosimetry department has been established from the current medium-term research plan period as a department to perform all aspects of basic and applied research concerning radiation measurement and dosimetry as the basis for all kinds of radiation-related research and development. Its wide-ranging specific research content includes research and development into radiation measurement technologies using the latest technology, physical research into medical imaging to contribute to advanced diagnosis, and also the rapid and accurate exposure dose estimation of patients exposed in various radiation exposure accidents, which is to say, physical and biological dose estimation.

Research Theme

Research and Development of Radiation Measurement Techniques using Advanced Technology

We are researching and developing techniques for measuring various qualities and doses (rates) of radiation incorporating the latest knowledge to achieve accurate dose evaluations. We engage in research and development that is contributing to advances in radiological sciences related to radiation dosimetry for treatment and diagnosis, atomic energy, and terrestrial and space environments in cooperation with national and international research institutions. In addition, we also support leading-edge research and development in the fields of physics and biology by making full use of advanced radiation detectors.


Medical Imaging Physics Research

Positron emission tomography (PET) is used in clinical settings for cancer diagnosis, etc., and is one of the most promising means of promoting molecular imaging research, however it still has not reached its full potential. Specifically, there are still strong demands for higher resolution, higher sensitivity and lower cost, and there is global competition in the research and development of next-generation PET systems. Therefore, we are aiming for a future in which cancer and brain disease are no longer problems by promoting the research and development of next-generation PET systems and elemental technologies based on cooperation between businesses and universities. In particular, based on our DOI detector, our core technology that is the first in the world to be successfully utilized in practice, we will continue developing novel PET systems.

Research on Internal Dosimetry

Internal exposure occurs as a consequence of the intake of radionuclides via inhalation or ingestion. The internal dose assessment is performed as follows: firstly conducting direct measurements of the subject or bioassay depending on the type of the radionuclide, secondly estimating the initial intake taking into account the physiochemical characteristics and the biokinetic behavior of the radionuclide. For providing an accurate and rapid internal dose estimates in an emergency, we are studying simulations for evaluating the response of in vivo counters using numerical phantoms that are anatomically-accurately reproduced, improving the speed of bioassay procedures, analyses of new biokinetic models of the radionuclides, and so on.


Research on External Dosimetry

Exposure to radiation from outside the body is called as external exposure. We estimate organ dose and effective dose in external exposure by measuring phantoms and using simulations. In particular, medical exposure in radiology and radiotherapy are the main subject of our research. In addition, we are developing comprehensive exposure assessment methods for everything from low level exposure, such as that received from the environment, to higher level exposure, such as that received in radiotherapy.

Research on Biological Dosimetry

A reference dose-response curve for low-dose ionizing radiation exposure has been determined using fluorescence in situ hybridization (FISH), with three differentially colored chromosome painting probes used to detect exchange-type chromosome aberrations [translocations and dicentric chromosomes].


Research Team

  • Radiation Measurement Reserach Team
  • Imaging Physics Team
  • Internal Dosimetry Team
  • External Dosimetry Team
  • Biodosimetry Team


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4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan Tel: +81-43-206-3025 (outside of Japan), or 043-206-3025 (in Japan)