Previous studies (Yamaguchi: JJMRM, 38, 2018) have observed variations in assignment of pregnant workers to magnetic resonance imaging (MRI) duty. This study analyzed background factors of the 7.6% “Proactive Personnel Placement” from the previous research. “Workers’ personal attributes” and “workplace characteristics” were rarely involved. However, “physical loads” played an important role. When MRI work was regarded as an alternative work placement, “exposure protectability” and “flexible work arrangements” were considered critical, and reduction of the physical load for workers was an option. Concerns regarding exposure (residual risk) warranted precaution. Providing information on the elements of concern is important while assigning MRI work placement.

The purpose of this study was to address regional uneven distribution of healthcare resources related to medical imaging. We measured Gini’s coefficient and the coefficient of variation based on the “Survey of Medical Institutions ” (number of Radiological Technologists, Serial angiography, Mammography, RI exam, PET, CT, MRI, 3D image processing) to compare potential regional differences. In addition, we evaluated regional features using a hierarchical cluster analysis. Our study reveals that the number of “Radiological Technologists ” presented a lower regional difference compared to physicians, as opposed to “Medical imaging ” that presented a higher regional difference than physicians. Furthermore, our study classified all 47 prefectures into seven clusters that describe and define the features of each region. We suggest that the results of this study will be useful for the efficient planning and improvement of the medical care provision system in each prefecture.

Chest X-ray (CXR) is the most commonly used diagnostic examination in lung cancer screening. The temporal subtraction (TS) processing of CXRs using computer-aided diagnosis (CAD) software is a technique in which a previous CXR is used to enhance evaluation of changes in an intervening time. However, if the superpositioning of the two images is not accurate, excessive misregistration artifacts will make it diffi cult for radiologists to differentiate between true changes and simple artifacts. In this study, we aimed to use bone suppression (BS) processing as a method to reduce artifacts when detecting a lesion became diffi cult due to the occurrence of artifacts between two images. The contrast-to-noise ratios (CNRs) of TS processing images with and without BS processing were calculated and compared based on several types of positions including anterior inclination, lateral inclination, right anterior oblique (RAO), and left anterior oblique (LAO). Our results showed that CNRs were signifi cantly improved with BS processing.

The slot scan technology for long-length radiography installed in the fluoroscopic imaging equipment performs continuous radiographing while the X-ray tube and the light-receiving unit simultaneously move in parallel, creating a long-length image. The disadvantage is that the exposure while moving creates a blurred image looking with reduced contrast, contributing to low image quality. Although the cause is related to the combination of exposure time and tube voltage, the conventional contrast improvement method cannot be applied due to the infl uence of blurring, and there is no physical evaluation report, only a visual evaluation report.

In this study, we analyze the blur part and propose a method to calculate the source of the new concept of contrast quantitatively.

The conventional manual for surface contamination screening method following a nuclear disaster dictates that the required screening processes should last for 3 minutes. However, the manual did not describe the specific procedure that should be followed. As a result, surveyors performed many unnecessary operations, which, in turn, facilitated increased fatigue and exhaustion. Therefore, the Yokosuka and Miura Radiological Technologists’ Association special dispatch team for nuclear disasters devised the segment method with the purpose to screen populations at a rate of 3 minutes per person. The segment method divides the whole body into six regions and screens in one-stroke sketch manner. As a result, we were able to clarify the precise time allocation and to stabilize the operation speed. Furthermore the segment method is easy to operate, prevents potential errors or omissions in the screening areas, and also reduces the physical burden on the surveyor.

In recent years, through questionnaire surveys, the importance of radiographic assistance in interpretation for medical examinations and emergency care has become clear. However, there have been no reports on radiographic assistance in interpretation in general imaging in daily practice, where it is considered to be the most frequently used. Therefore, we constructed a radiographic assistance in interpretation for general imaging, using the image reproduction function. As a result, we could prevent the oversight of abnormal findings in three cases out of a total of 57 cases, in which image replication was performed within 1 year, from September 1, 2017 to August 31, 2018. These facts suggest that the radiographic assistance in interpretation provided by medical radiologists, who use the image reproduction function, also plays a role in double-checking general imaging work in daily practice, revealing its usefulness.

Semiconductor rectal dosimeters are useful for patient monitoring during brachytherapy. Many authors have reported a variety of characteristics such as a decrease in sensitivity with irradiation history. Additional characteristics such as the dose rate dependence, dose per pulse dependence, sensitivity variation with temperature, dose linearity, and directional dependence have also been reported. However, the trend of these characteristics with irradiation history has not been well investigated. Approximately three years have passed since we introduced a new n-type silicon semiconductor rectal dosimeter in our hospital. Therefore, the purpose of this study is to investigate sensitivity, dark current noise, dose rate dependence, sensitivity variation with temperature of the semiconductor rectal dosimeter, and changes in the characteristics with brachytherapy irradiation history.

An n-type silicon semiconductor rectal dosimeter system (Intracavitary Detector IDF-5 channels) was used in this study. Measurements were performed with a High Dose Rate (HDR) Iridium-192 brachytherapy source. The radiation source was placed between the semiconductor detector and the Farmer-type ion chamber in a water phantom system. The ratio of the reading by the semiconductor dosimeter to the absorbed dose by the Farmer chamber as a reference was defined as the sensitivity index value of the semiconductor. Several characteristics were investigated by evaluating their sensitivity index.

For all the channels, the relative sensitivity decreased to approximately 0.92–0.95, with an irradiation history of approximately 200 Gy. Dark current noise values tended to converge towards zero according to the irradiation history. Dose rate dependence for HDR source strength was not observed, and it was not related to the irradiation history. Although there was sensitivity variation with temperature, it was small after irradiation history.

The identified characteristics may affect the actual measurement results. However, when sensitivity calibration is performed under appropriate conditions, they can be effectively used for rectal dose monitoring during brachytherapy.

Around 10 years ago the Japan Medical Imaging and Radiological Systems Industries Association (JIRA) published a checklist to be followed at start-up and end-of-work of radiation-related equipment. However, recent angiography systems are diversified in model and function, and there is a possibility that the daily inspection being performed as per the published inspection table is insufficient. Upon investigating the daily inspection table of each facility, we observed that 13.5% of the apparatuses use the JIRA inspection table, and the contents and quality of inspection are diverse.

In this study, we developed a daily inspection table with respect to the currently used models and applications for the purpose of correcting the disparity in daily inspection protocols among facilities and standardizing the daily quality control of systems. We propose that incorporation and implementation of the inspection items described in this study can improve the quality control output.

Purpose. This study aimed to investigate the relationship between students’ modalities of interest in clinical practical training during radiological technologist education and their degree of learning for those modalities. Methods. The target is 2019 fourth-year students of Suzuka University of Medical Science. The same questionnaire survey was administered to participating students before and after clinical training. In the first part of the questionnaire, students ranked the modalities of radiological technologists’ duties by their level of interest. The second part of the questionnaire assessed their learning level for each modality. In this study, the technical term for each modality was presented individually, and participants’ level of understanding of these technical terms was defined as the learning level for that modality. Results. The modalities of the radiological technologists’ work in which students were most interested were general radiography, computed tomography, and magnetic resonance. The interest in these modalities did not change between before and after clinical training. Students’ learning levels were particularly high in the modalities of interest. Conclusion. We investigated changes in students’ interest in modalities attributable to clinical practical training during radiological technologist education and identified the relevance of the degree of learning for those modalities. We aim to use these data to inform educational improvements.

This study aimed to evaluate the effects of visceral fat area, abdominal circumference, and body mass index (BMI) on X-ray computed tomography (CT) and the effect of comments on results.

In this study, subjects were recruited for 94 months, and 232 subjects were assessed for visceral fat area, BMI, and abdominal circumference, and images and guidance comments were distributed as reports to the subjects.

As a result, 57.6% of the subjects had visceral fat accumulation. These subjects were instructed to improve their lifestyle after 6 months and reexamined. However, only 9.7% of the subjects followed it. Those who followed the reexamination instructions did not reduce BMI or abdominal circumference but tended to reduce visceral fat area.

We conclude that the motivating effect of this study is limited. However, it was estimated that visceral fat area was likely to be reduced, even if the reexamination did not reduce weight and abdominal circumference.

In 2011 the International Commission on Radiological Protection recommended that “the threshold dose for cataracts and the lens equivalent dose limit should be significantly reduced”, and the Ministry of Health, Labour and Welfare has notified medical institutions to strengthen measures to protect eye lenses from radiation exposure. This shows the necessity to protect medical professionals by using equipment with increased levels of protection.

This study developed new radiation protective eyewear in accordance with Japanese Industrial Standards (JIS) for eye lens exposure, and conducted basic evaluations of the protection efficiency in angiography, general radiography, fluoroscopy, and C-arm applications. The results showed that these newly developed radiation protective eyewear provide a high level of radiation protection.