Small-animal molecular imaging is recognized as a method that bridges basic study and clinical research. However, the imaging system is not easily available to everyone due to the peculiarity of handling and management. Here the author describe the basic of preclinical positron emission tomography (PET) and single photon emission computed tomography (SPECT) for beginners.

Institute of Environmental Radioactivity (IER) at Fukushima University stores approximately 18,000 soil samples received from the Nuclear Regulation Authority, which were collected after the Fukushima Daiichi Nuclear Power Plant accident. The IER is providing a loan service of the archive soil samples and using a database system for the samples. The database system consists of two parts: a data set of the soil samples collected during the first to seventh survey, and a system called ARASO (Assessment Database System for Radioactivity in Soil) which allows us to view and search the soil data from the first survey on a map. ARASO has useful functions, such as, calculating of radioactivity in the specified area and searching for the soil samples according to the research object. It is highly expected that ARASO will promote the utilization of archive soil samples and contribute to the research progress on the radioactivity assessment as well as the fate of radioactive materials in the environment.

Responses of well-type ionization chambers for HDR brachytherapy may depend on source models and chamber models. This work determined a radiation quality correction factor k_source. Two types of ⁶⁰Co sources and two types of ¹⁹²Ir sources including a new source model were used for this study. This correction factor can convert the calibration coefficient for reference air kerma rate of mHDR-V2r to that of the other source models. We have reported source geometry factors k_sg which are applied to VS2000 and Ir2.A85-2 users in 2019. In this study, k_sg was updated to k_source, which made it possible to correct the difference of the response due to source geometry and gamma ray energy. We expect that this work makes almost all Japanese HDR users enable to use domestic calibration service.