• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.59-64
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• 2010

We examined the accuracy and efficiency of phantom by applying the designed phantom in order to check daily quality assurance easily by objective criteria and to confirm daily quality assurance of linear accelerator, simulator, and CT-simulator. The results of 10 weeks of linear accelerator output dose using American Association of Physicists in Medicine(AAPM) daily quality assurance guide were measured within ${\pm}1%$ of error. Mechanical check of laser alignment, optical distance indicator(ODI), CT scanner laser and alignment of gantry lasers with the center of imaging plane were measured within ${\pm}1mm$. Daily average working time for daily quality assurance of radiation therapy equipments was 38 minutes. The designed phantom was easy to install and daily quality assurance was possible with only one installation. The aspects reproducibility and efficiency as well as accuracy of quality assurance were excellent.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.15-18
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• 2010

Main component of radiography barrier aprons is lead. To manufacture a lead-free barrier sheath, barium sulfate and organic iodine-based chemicals should be mixed with rubber. Barrier capacity was tested in the medical field. To improve adaptation of rubber with the mixture, raw materials went through milling, agitation, and extruding processes. Three sheaths were manufactured with 30%, 80%, and 120% sulfate barium, respectively. This study found 10% lower barrier capacity of lead-free barrier than the traditional lead-containing rubber sheath. Problems, however, were confronted during the agitation and extruding processes. Mixing with rubber was a technically demanding job. Inconsistent depth, problems with thermal processing and dissipation were encountered as well.

• Korean Journal of Digital Imaging in Medicine
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• v.11 no.2
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• pp.93-99
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• 2009

This conclusion was from the 3rd grade students of radiologic technology of Daegu Health College who already taken the hospital practice. 231 students answer our question and this study used sampling method. The contents of Questionnaire consisted of normal facts of respondent, Training satisfaction, Training Methods, Practice Environment of Hospital, Problem in Practice Hospital, Before and after views, etc. The statistical program SPSS/Win 10.0 version was used to see the results of the survey data used in. The response contents of brief question were separetely checked and clean.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.377-383
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• 2015

This study evaluates the convergence radiation protection performance by measuring the PSNR(peak signal-to-noise ratio) values of the image J in the image evaluation program based on increased relative to this exposure of radiation workers.The aim of this study was to evaluate radiation protection performance of apron for design of it's basic information. Method was used to PSNR of Image J program and good condition apron was more than 27dB, the PSNR value of poor condition apron appeared to be less than 24dB. The result is the normality were satisfied distribution and T-test values were statistically significant with p<0.001. Results of evaluation of the performance protective apron through the more easily accessible experimental conditions and methods in the clinical was confirmed distinctly different. in order to reduce the radiation exposure we need to evaluate convergence protection performance and to be having a good performance apron.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.141-142
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• 2016

의료 기관에서 정확한 진단하기 위해 아날로그 시스템인 Film System보다 Digital System을 선호하고, 장비의 설치 또한 Digital System으로 많이 보급이 되고 있다. 장비가 많이 보급이 되었지만 현재 장비에 대한 안전관리나 품질관리는 미흡하다고 할 수 있다.이에 본 연구는 Digital System의 품질관리의 중요성을 알리고, 품질관리의 항목을 설정하여, 기준 값을 제시하고자 3개월 동안 SNR, MTF, DQE를 측정한 결과 다음과 같이 나타났다. 1달은 SNR 4.02, MTF 50% 4.6lp/mm, DQE는1.4로 측정이 되었다. 3주후 SNR은 3.55, MTF 50% 3.0lp/mm, DQE는 0.7로 나타났다. 3개월 뒤 SNR은 3.45, MTF 50% 2.1lp/mm, DQE는 0.5로 나타났다. 시간이 지나갈수록 영상의 디지털영상의 물리적 평가들이 저하되는 것으로 나타났다. 시간이 지나감에 따라 의료영상이 저하됨에 따라 안전관리 뿐만 아니라 영상의 품질관리도 같이 이루어져야 할 것이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.365-365
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• 2012

본 연구에서는 X-ray 영상을 얻기 위한 검출기 중 직접 검출방식에 쓰이고 있는 광도전체(Photoconductor)의 전극으로 Au를 사용하여 전기적인 특성을 파악하였다. Au는 유기물에 대한 반응이 적고 전기 전도도가 좋은 물질로서 투명전극으로 많이 쓰이고 있는 인듐 주석 산화물(ITO)을 대체할 수 있는 물질로 각광받고 있다. 우선 시편 제작을 위해 투명한 기판(Corning Glass, 0.7t)위에 하부전극으로 Au를 $3cm{\times}3cm$의 크기로 Physical Vapor Deposition(PVD) 방식을 이용하여 증착하였다. 이 때 챔버 내 저진공은 Rotary Pump를 이용하여 $3.9{\times}10-2Torr$ 이하를 유지하고 고진공은 Diffusion Pump를 이용하여 $5.3{\times}10-5Torr$ 이하를 유지하였다. 완성된 하부전극 위에 광도전체인 $HgI_2$를 폴리머 물질에 교반하여 메탈 폴리머 결합을 가진 Paste를 제조하고 이 Paste를 Screen Printing Method를 이용하여 증착 후 건조하였다. 마지막으로 시편위에 상부전극을 하부전극과 같은 조건으로 증착함으로서 시편을 완성한다. 상하부 전극으로 쓰이는 Au의 증착 조건을 변화시키면서 그에 따른 시편의 전기적인 특성 변화를 관찰하였다. 그 결과, Au의 증착온도와 질량에 따라 특성이 변화함을 알 수 있었다. 본 연구의 결과를 통해 디지털 방사선 검출기에서 Au 전극의 적용 가능성을 확인하였으며, 추후 Au 증착 조건의 최적화를 통해 방사선 검출기의 효율 향상을 위한 연구를 하고자 한다.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.85-91
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• 2010

Digital radiography has been replacing rapidly the analog radiography for diagnosis of pneumoconiosis. The purpose of this study is to compare quality control of digital radiography (DR) and analog radiography (AR) for chest radiography in medical institution for pneumoconiosis (MIP) For the first time, we visited MIP to evaluate the chest radiography which is used for patients with pneumoconiosis, including equipment, technical parameters and reading environment. There were 33 institutions. DR and AR were installed in 24 and 9 institutions, respectively. Between DR and AR, we compared the radiological technique (RT), image quality (IQ) and reading environment (RE) to use the guideline published by Occupational Safety and Health Research Institute (OSHRI). The image quality was rated by two experienced chest radiologists for pneumoconiosis with certified from OSHRI. The chest radiography equipment was not significantly difference between AR and DR, but there were significantly difference in tube voltage and grid ratio used for chest radiography except to tube current, exposure time. Statistically, DR is significantly higher in RT(70.3 vs. 43.8, p = 0.009), RE(77.7 vs. 33.3, p = 0.004) than AR, but it's not significantly difference in IQ (65.6 vs. 52.8, p = 0.050). AR and DR in RT were passed 33.3%, 75.0% respectively (p = 0.044) and 44.4%, 79.2% (p = 0.090) in IQ and 44.4%, 91.7% (p = 0.009) in RE. In MIP, DR needs to replace AR in diagnosis of pneumoconiosis.

• Journal of Radiation Protection and Research
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• v.35 no.1
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• pp.26-33
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• 2010

A computed Radiography (CR) system by use of reusable Image Plate (IP) offers a convenient and reliable way to replace a conventional film-screen system for NDT (non-destructive testing) field. The quality of a radiography to detect a defect of welded objects depends on the procedure embracing several factors such as measurement conditions, image plate type/class, radiation energy, radiation type, and source to image plate distance. Also, the ability of images to detect a flaw reduces with increasing object thickness. In the study, the properties of gamma ray source were summarized for NDT field and inspection images of CR image system manufactured by FUJI were acquired using $^{75}Se$ and $^{192}Ir$ with welded objects. We analyzed the gray scale of hole defect image by using XCAP image processing program and calculated the image contrast and SNR in definition. Also the sesitivities of image quality indicator(IQI) were calculated for hot and cooling tube image of $^{75}Se$ and $^{192}Ir$.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.4
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• pp.195-201
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• 2020

This study studied scoliosis, one of the most common modern diseases caused by lifestyle patterns of office workers sitting in front of computers all day and modern people who use smart phones frequently. Scoliosis is a typical complication that takes more than 80% of the nation's total population at least once. X-ray are used to test for these complications. X-ray, a non-destructive testing method that allows scoliosis to be easily performed and filmed in various areas such as the chest, abdomen and bone without contrast agents or other instruments. We uses NI DAQ to miniaturize digital X-ray imaging devices and image intensifier in self-shielding housing with Vision Assistant for drawing lines to the top and the bottom of the spine to acquire angles, i.e. curvature in real-time. In this way, the research was conducted to see scoliosis patients and their condition easily and to help rapid treatment for solving the problem of posture correction in modern people.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.897-904
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• 2022

The purpose of this study is to compare the difference in dose and image quality when applying the diagnostic reference level (DRL) test conditions for head radiography in a digital radiation environment and the test conditions currently applied in clinical practice. I would like to review the conditions of radiographic examination. In this study, the head model phantom was targeted, and the investigation conditions were divided into clinical conditions (Clinic), DRL value (DRL₇₅), and DRL average value (DRL_mean). For dose, Enterance surface dose (ESD) was measured, and for image quality, signal-to-noise ratio and contrast-to-noise ratio were measured and analyzed for comparison. The average values of skull anterior posterior(AP) ESD according to the changes in test conditions were Clinic 1214.03±4.21 µGy, DRL₇₅ 3017.83±8.14 µGy, DRL_mean 2283.50±7.09 µGy, and skull lateral (Lat). The average value of ESD was statistically significant with Clinic 762.79±3.54 µGy, DRL₇₅ 2168.57±10.83 µGy, and DRL_mean 1654.43±6.48 µGy (p<0.01). The average values of SNR and CNR measured in the orbital, maxillary sinus, frontal sinus, and sella turcica were statistically significant (p<0.01). As a result of this study, compared to DRL, the conditions used in clinical practice showed lower dose levels of about 58% for AP and about 70% for Lat., and there was no qualitative difference in terms of image quality. Through this study, it is necessary to consider a new diagnostic reference level suitable for the digital radiation environment, and it is considered that the dose should be reduced accordingly.