• Korean Journal of Radiology
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• v.23 no.9
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• pp.847-852
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• 2022

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.267-268
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• 2002

Microbeam is a new avenue of radiation research especially in radiation biology and radiation protection. Selective irradiation of an ionizing particle to a targeted cell organelle may disclose such mechanisms as signal transaction among cell organelles and cell-to-cell communication in the processes toward an endpoint observed. Bystander effect, existence of which is clearly evidenced by application of the particle microbeam to biological experiments, suggests potential underestimation in the conventional risk estimation at low particle fluence rates, such as environment of space radiations in ISS (International Space Station). To promote these studies we started the construction of our microbeam facility (named as SPICE) to our HVEE Tandem accelerator (3.4 MeV proton and 5.1 MeV $^4$He$\^$2+/). For our primary goal, "irradiation of single particle to cell organelle within a position resolution of 2 micrometer in a reasonable irradiation time", special features are considered. Usage of a triplet Q magnet for focussing the beam to submicron of size is an outstanding feature compared to facilities of other institutes. Followings are other features: precise position control of cell dish holder, design of the cell dish, data acquisition of microscopic image of a cell organelle (cell nucleus) and data processing, a reliable particle detection, soft and hard wares to integrate all these related data, to control and irradiate exactly determined number of particles to a targeted spot.

• Progress in Medical Physics
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• v.28 no.2
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• pp.49-53
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• 2017

The energy distribution was calculated for an electron beam from an electron linear accelerator developed for medical applications using computational methods. The depth dose data for monoenergetic electrons from 0.1 MeV to 8.0 MeV were calculated by the DOSXYZ/nrc code. The calculated data were used to generate the energy distribution from the measured depth dose data by numerical iterations. The measured data in a previous work and an in-house computer program were used for the generation of energy distribution. As results, the mean energy and most probable energy of the energy distribution were 5.7 MeV and 6.2 MeV, respectively. These two values agreed with those determined by the IAEA dosimetry protocol using the measured depth dose.

• Journal of Korean Society for Quality Management
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• v.26 no.4
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• pp.189-201
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• 1998

Quality of radiological services can be assessed by various agents, so called medical doctors, radiologists, patients and others. However radiological services are provided by radiologists to patients and medical doctors. This study was based on data which were collected from assessment of 142 radiologists working in the health care services organization and 149 patients who visited the same organization about radiological services, with self-administered structured questionnaire. This study was planned to analyze of radiological services factors and to develop a methodology for measuring the level of quality in the radiological health care services.

• Journal of radiological science and technology
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• v.46 no.1
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• pp.43-52
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• 2023

The purpose of this study was to investigate the actual conditions related to the working environment of radiological technologist who is working in small or medium-sized hospitals or clinics. The results of this study were intended to improve the working environment of radiological technologist and care for patients. For data collection, a structured questionnaire was used as a research tool, and 838 women (52.4%) were used as a general characteristic of 1,598 people subject to this questionnaire. The annual salary of radiological technologists with less than one year experience was 33.76 million won, and the average annual salary of radiological technologists with more than 10 years of experience was 41.33 million won. It showed an increased of 1.84% per year. Among 1,540 radiological technologists, 879 workers were paid holiday work allowances, 340 workers did not, and 321 holiday workers work during the week. In addition, a total of 817 workers received overtime payment, of which 112 received overtime wage on a monthly basis regardless of the overtime hours. In addition, a total of 348 radiological technologists were not paid overtime wage, and 138 workers were included in the basis salary. There were no union in 85% of the them. According to the results of this study, the wages and working environment of radiological technologists in small or medium-sized hospitals or clinics were not appropriate. Therefore, the efforts of the radiological association and its members are necessary to provide a better working environment for radiological technologists. In addition, it is expected that this study will be used as basic data for the association's policy to improve the working environment of members who work in poor conditions.

• Korean Journal of Radiology
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• v.22 no.6
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• pp.912-921
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• 2021

Objective: To compare the performance of the deep learning-based lesion detection algorithm (DLLD) in detecting liver metastasis with that of radiologists. Materials and Methods: This clinical retrospective study used 4386-slice computed tomography (CT) images and labels from a training cohort (502 patients with colorectal cancer [CRC] from November 2005 to December 2010) to train the DLLD for detecting liver metastasis, and used CT images of a validation cohort (40 patients with 99 liver metastatic lesions and 45 patients without liver metastasis from January 2011 to December 2011) for comparing the performance of the DLLD with that of readers (three abdominal radiologists and three radiology residents). For per-lesion binary classification, the sensitivity and false positives per patient were measured. Results: A total of 85 patients with CRC were included in the validation cohort. In the comparison based on per-lesion binary classification, the sensitivity of DLLD (81.82%, [81/99]) was comparable to that of abdominal radiologists (80.81%, p = 0.80) and radiology residents (79.46%, p = 0.57). However, the false positives per patient with DLLD (1.330) was higher than that of abdominal radiologists (0.357, p < 0.001) and radiology residents (0.667, p < 0.001). Conclusion: DLLD showed a sensitivity comparable to that of radiologists when detecting liver metastasis in patients initially diagnosed with CRC. However, the false positives of DLLD were higher than those of radiologists. Therefore, DLLD could serve as an assistant tool for detecting liver metastasis instead of a standalone diagnostic tool.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.627-635
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• 2018

The purpose of this study was to compare the job stress, job satisfaction, turnover intention, and job performance feelings of radiological technologists, physical therapists, and medical laboratory technologists working at university hospitals and general hospitals. The subjects were 114 general practitioners and 217 university hospital workers who are engaged in occupations of radiological technologists, physical therapists, and medical laboratory technologists in the age groups 20-50 years living in Incheon Metropolitan City. Data collection was conducted from April 1, 2017 to April 30, and data analysis was performed using the SPSS/WIN 23 statistical program. There were statistically significant difference in the job stress of medical technician by age, marriage, occupation, hospital size, position, parenting form, employment type, and lunch break. Job stress by occupation was highest in medical laboratory technologists, followed by radiological technologists and physical therapists. Job satisfaction was the highest among physical therapists. followed by radiological technologists and medical laboratory technologists. There were significant differences in age, occupation, parenting form, type of employment, and lunch break according to demographic characteristics. In order to reduce the job stress and job satisfaction of the medical technician working at the hospital, the development of the job environment should be sought and the hospital should also be removed from the authoritarian management system.

• Korean Journal of Radiology
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• v.24 no.4
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• pp.284-293
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• 2023

Objective: To validate a simplified ordinal scoring method, referred to as modified length-based grading, for assessing coronary artery calcium (CAC) severity on non-electrocardiogram (ECG)-gated chest computed tomography (CT). Materials and Methods: This retrospective study enrolled 120 patients (mean age ± standard deviation [SD], 63.1 ± 14.5 years; male, 64) who underwent both non-ECG-gated chest CT and ECG-gated cardiac CT between January 2011 and December 2021. Six radiologists independently assessed CAC severity on chest CT using two scoring methods (visual assessment and modified length-based grading) and categorized the results as none, mild, moderate, or severe. The CAC category on cardiac CT assessed using the Agatston score was used as the reference standard. Agreement among the six observers for CAC category classification was assessed using Fleiss kappa statistics. Agreement between CAC categories on chest CT obtained using either method and the Agatston score categories on cardiac CT was assessed using Cohen's kappa. The time taken to evaluate CAC grading was compared between the observers and two grading methods. Results: For differentiation of the four CAC categories, interobserver agreement was moderate for visual assessment (Fleiss kappa, 0.553 [95% confidence interval {CI}: 0.496-0.610]) and good for modified length-based grading (Fleiss kappa, 0.695 [95% CI: 0.636-0.754]). The modified length-based grading demonstrated better agreement with the reference standard categorization with cardiac CT than visual assessment (Cohen's kappa, 0.565 [95% CI: 0.511-0.619 for visual assessment vs. 0.695 [95% CI: 0.638-0.752] for modified length-based grading). The overall time for evaluating CAC grading was slightly shorter in visual assessment (mean ± SD, 41.8 ± 38.9 s) than in modified length-based grading (43.5 ± 33.2 s) (P < 0.001). Conclusion: The modified length-based grading worked well for evaluating CAC on non-ECG-gated chest CT with better interobserver agreement and agreement with cardiac CT than visual assessment.

• Journal of radiological science and technology
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• v.18 no.1
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• pp.55-62
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• 1995

This study was performed to find out dose distribution, pdd, surface dose and off center ratio. A few articles is analysis of dose data in radiotherapy field, there is no standardized measure of an assessment of exposure dose at diagnostic radiology, yet. And authors demonstrated a new assessment measure by ion chamber, TLD and film dosimetry system. We assurance that our data is useful to quantiative analysis of exposure dose and clinical fields for reduction of radiation dose.

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.176-176
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• 2003