• Journal of radiological science and technology
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• v.38 no.4
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• pp.331-336
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• 2015

Medical electrical equipment - Part 1: General requirement for basic safety and essential performance of MFDS was revised as 3th edition and Medical electrical equipment Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment will be expected to be announced as notification. Therefore this technical report was written to introduce provision of the particular requirements, replacement, addition, amendment. The purpose of this particular requirements is to secure requirements for basic safety and essential performance of X-ray equipment for radiography and radioscopy. X-ray high voltage generator, mechanical protective device, protection against radiation is included in this particular requirements. Medical electrical equipment - Part 1, Part 1-2, Part 1-3 is applied to this particular requirements. If the requirements is announced as notification, It is expected to widen understanding for basic safety and essential performance of X-ray equipment for radiography and radioscopy and play a part to internationalize of medical equipments.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.35-42
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• 2003

Methodology for calculating the organ equivalent doses and the effective doses of pediatric and adult patients undergoing medical X-ray examinations were established. The MIRD-type mathematical phantoms of 4 age groups were constructed with addition of the esophagus to the same phantoms. Two typical examination procedures, chest PA and abdomen AP, were simulated for the pediatric patients as well as the adult as illustrative examples. The results confirmed that patients pick up approximate 0.03 mSv of effective dose from a single chest PA examination, and 0.4 to 1.7 mSv from an abdomen AP examination depending on the ages. For dose calculations where irradiation is made with a limited field, the details of the position, size and shape of the organs and the organ depth from the entrance surface considerably affect the resulting doses. Therefore, it is important to optimize radiation protection by control of X-ray properties and beam examination field. The calculation result, provided in this study, can be used to implement optimization for medical radiation protection.

• Journal of the Korean Society of Radiology
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• v.10 no.3
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• pp.201-206
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• 2016

Social interest in breast cancer has increased. The most basic exams for diagnosis include breast X-ray and breast ultrasound. In particular, breast microcalcification requires histological diagnosis, and breast microcalcification biopsy is commonly performed. Therefore, this study aimed to analyze and assess X-ray guided biopsy (needle localized open biopsy) and ultrasound guided biopsy (sono guided core needle biopsy), which are basics in diagnosis of microcalcification. Targeting 241 cases in which magnification mammography was performed for patients who visited the hospital due to breast microcalcification, age distribution and the location of lesions were analyzed in X-ray guided biopsy and ultrasound guided biopsy. By classifying exams performed after magnification mammography, the frequencies of X-ray guided biopsy and ultrasound guided biopsy were analyzed, and malignant and benign results were confirmed. The results showed that 64 cases(26.6%) were X-ray guided biopsy, which was 5.4 times higher than 12 cases(4.9%) of ultrasound guided biopsy. Due to development of ultrasound equipments, stereotactic vacuum-assisted biopsy, etc. the methods of histological diagnosis of microcalcification have become diverse, but when considering characteristics and limitations of each exam, X-ray guided biopsy is thought to be most accurate and useful.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.400-414
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• 2021

Under high-level radioactive waste repository conditions, bentonite as an engineered barrier material undergoes thermal, hydrological, mechanical, and chemical processes. We report the applications of X-ray Computed Tomography (CT) imaging technique on the characterization and analysis of bentonite over the past decade to provide a reference of the utilization of this technique and the recent research trends. This overview of the X-ray CT technique applications includes the characterization of the bentonite either in pellets or powder form. X-ray imaging has provided a means to extract grain information at the microscale and identify crack networks responsible for the pellets' heterogeneity. Regarding samples of pellets-powder mixtures under hydration, X-ray CT allowed the identification and monitoring of heterogeneous zones throughout the test. Some results showed how zones with pellets only swell faster compared to others composed of pellets and powder. Moreover, the behavior of fissures between grains and bentonite matrix was observed to change under drying and hydrating conditions, tending to close during the former and open during the latter. The development of specializing software has allowed obtaining strain fields from a sequence of images. In more recent works, X-ray CT technique has served to estimate the dry density, water content, and particle displacement at different testing times. Also, when temperature was added to the hydration process of a sample, CT technology offered a way to observe localized and global density changes over time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.829-840
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• 2001

In this study, we propose a method for quantifying the degree of advance of pulmonary emphysema by using chest X-ray images. With this method, we devise two schemes for this purpose. One is for detecting blood vessels by using a deformable model with the tree-like structure and using an evaluation function specialized by knowledge about blood vessels appeared in chest X-ray images, and the other is for quantifying the degree of advance by using several features, which were extracted from blood vessels, and the equation of quantitative evaluation. In order to evaluate the performance, we applied the proposed method to 189 ROIs(Regions of Interest) of ten chest X-ray images and compared the values by the proposed method with those by a medical doctor.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.351-364
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• 2020

Missed lung cancers on chest radiograph (CXR) may delay the diagnosis and affect the prognosis. CXR is the primary imaging modality to evaluate the lungs and mediastinum in daily practice. The purpose of this article is to review chest radiographs for common blind spots and highlight the importance of various radiologic presentations in primary lung cancer to avoid significant diagnostic errors on CXR.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.833-838
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• 2011

X-ray device used in the diagnosis has made possible to have more effective and accurate diagnosis, powered by the development of various devices. Based on this, X-ray device has become the most basic and essential diagnostic equipment in clinical medicine. At present, in the image acquisition field using X-ray, the use of Digital radiography which is useful in the acquisition time reduction and transfer of images and is possible to have the dose reduction has expanded. With the structure using one detector, this DR device has disadvantages in that it needs structural changes unlike existing X-ray and the detector should be moved to the desired position depending on the shooting location. Therefore, in this study, using BLDC(Brushless direct current) motor and PID(Proportional integral differential) control method, the automatic control system of 3-axis which is upward and downward, left and right and rotation of detector where having the most movement in DR was designed and produced and its performance was evaluated.

• Journal of the Korean earth science society
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• v.27 no.5
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• pp.521-527
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• 2006

The EPMA analysis for CHIME dating requires standard materials, which include nuclear fuel materials that are rare and sensitive to handle. Any laboratory that does not meet these standards has had difficulties adopting the CHIME dating method. We have developed a working standard technique for CHIME dating to prepare standard materials without use of nuclear fuel materials. Mineral samples, such as small pieces of monazite that are homogeneous in X-ray intensities, are calibrated using well-characterized primary standards in one laboratory. Once this procedure is done, they can be readily usable as working standards in the other laboratories, only with measurement of X-ray intensities. This method is applicable in preparing standard materials for both chemical compositions and determination of X-ray interference correction factors, and it is independent from chemical composition of mineral standard.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.337-344
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• 2016

The purpose of this study was to evaluate the radiolucency for the phantom output to the 3D printing technology. The 3D printing technology was applied for FDM (fused deposition modeling) method and was used the material of ABS (acrylonitrile butadiene styrene) resin. The phantom was designed in cylindrical uniformity. An image uniformity was measured by a cross-sectional images of the 3D printed phantom obtained from the CT equipment. The evaluation of radiolucency was measured exposure dose by the inserted ion-chamber from the 3D printed phantom. As a results, the average of uniformity in the cross-sectional CT image was 2.70 HU and the correlation of radiolucency between PMMA CT phantom and 3D printed ABS phantom is found to have a high correlation to 0.976. In the future, this results will be expected to be used as the basis for the phantom production of the radiation quality control by used 3D printing technology.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.262-266
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• 2013

A new concept of periapical radiography, intra oral x-ray tube and detector system is introduced. It is new system that a miniature x-ray tube is inserted into mouse and it acquired digital image using external detector. In this study, we have investigated temperature and dose distribution of insertional x-ray tube for periapical radiography. To analyze temperature characteristic of x-ray tube, we attached the thermocouple to surface of x-ray tube and we measured the temperature according to distance. Also, we measured the dose distribution of a miniature x-ray tube according to distance. As a result, temperature was constant to $27^{\circ}C$ over 2mm without cooling system, dose distribution of x-ray tube was 3.14 and 1.84mGy in 3 and 5cm, respectively. Therefore, the proposed x-ray system works in lower dose than conventional dental x-ray system. Thus, it is considered that new concept of system will have a significant effect on medical imaging technology.