• 한국방사선학회논문지
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• 제4권2호
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• pp.21-25
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• 2010

최근 진단 X선 검출기 적용을 위한 방사선 검출물질로 반도체 화합물에 대한 많은 연구가 되고 있다. 본 연구에서는 반도체 화합물 중 광민감도가 우수하고 X선 흡수율이 높은 CdS 반도체를 이용하여 검출센서를 제작하였으며, 진단 X선 발생장치에서의 에너지 영역에 대한 검출 특성을 조사함으로써 적용 가능성을 평가하였다. 센서 제작은 CdS 센서로부터의 신호 획득 및 정량화를 위한 Line voltage selector(LCV)를 제작하였으며, 전압감지회로 및 정류회로부를 설계 제작하였다. 또한 X선 노출조건에 따른 상호연과 알고리즘을 이용하였으면, DAC 컨트롤러와의 Interface board를 설계 제작하였다. 성능평가는 X선 발생장치의 조사조건인 관전압, 관전류 및 조사시간별 저항변화에 따른 전압파형 특성을 오실로스코프로 획득하여 ANOVA 프로그램을 이용하여 데이터를 통계 처리 및 분석하였다. 측정결과, 관전압과 관전류이 증가할수록 오차의 비가 감소하였으며, 90kVp에서 6%, 320 mA에서 0.4% 이하의 좋은 특성을 보였으며, 결정계수는 약 0.98로 1:1의 상관관계를 보였다. X선 조사시간에 따른 오차율은 CdS 물질의 늦은 반응속도에 기인하여 조사시간이 길어질수록 지수적으로 감소하는 것을 알 수 있었으며, 320 msec에서 2.3%의 오차율을 보였다. 끝으로 X선 선량에 따른 오차율은 약 10% 이하였으며, 0.9898의 결정계수로 매우 높은 상관관계를 보였다.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.516-521
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• 2009

X-ray system which is usefully used in diagnosis of the patient, being bombed of radioactivity is a big weak point when irradiates a X-ray to the human body so that ICRP restricted the radiation exposure tolerance of the human body. In order to reduce being bombed, the many research and development is now advanced. A lots of diagnostic X-ray machines have currently used due to the increase of occurrence efficiency of X-ray and precisely the output control by using the inverter which is a high speed switching semiconductors. For getting the confidence of the X-ray machine, the same radiation occurrence, same evaluation, and same irradiation condition are necessary when evaluates X-ray irradiation. It is the most important part for the accuracy of the test result and the patient safety. This research has produced the high voltage occurrence system of full-wave rectification method by using the LC resonance inverter, and evaluated the irradiation reproducibility in order to use it in diagnosis of the patient.

• 대한디지털의료영상학회논문지
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• 제14권1호
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• pp.13-20
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• 2012

In a normal x-ray examination, the cooperation of a patient in positioning greatly influences the improvement of work performance, the quality of the images and the reduction in time spent on the examination. An attempt was made to discover the connection between an examination information printout and the effects of the examination by informing the patient before the examination on the examination positions in order to increase the level of cooperation by the patient and by surveying the degree of satisfaction of the patient during the examination proceedings. An examination information printout was prepared on five positions that patients consider to be difficult while receiving normal x-ray examinations and were shown to 257 male and female patients between the ages of 30 to 79 who had visited this hospital between January 1 to February 29, 2012 or to a person who had accompanied the patients before the examination to research the degree of satisfaction regarding the printout. In addition, the examination explanation printout was given to Radiologic Technologists with over 1 year experience in this hospital to use while taking the x-rays and the degree of satisfaction was surveyed and it was examined if the increase of the degree of satisfaction had an effect on the reduction in the examination time. The patients who utilized the examination information printout revealed results of approximately a 7.8% higher degree of satisfaction among the patients who had previous experience receiving x-ray examinations compared to those were having an x-ray for the first time. In the age groups between 30 to 70 years of age, the age group in the 30's revealed the lowest level of satisfaction at approximately 69% and the group in the 50's showed the highest degree of satisfaction of 87.94%. In the survey of the Radiologic Technologists, 85% responded that they were satisfied. In the question that stated "Will the examination information printouts reduce the time involved in unnecessary conversations with the patients?," the responses showed a 95% degree of satisfaction. The degree of satisfaction was high over the examination information printout by both the patients and the Radiologic Technologists. Although the effects of examination time reduction varied based on the ages of the patients and physical conditions that they were in and could not be given measurement values, it was able to be seen through the survey that reduction of the unnecessary communication between the patient and the Radiologic Technologists contributed to the increase in the degree of satisfaction. As a result, both the patients and the Radiologic Technologists had an increased degree of satisfaction over the examination information printout and it was possible for improvements to be made in the quality of medical service provided as well. Nevertheless, it is considered that a more developed manual in terms of quality and quantity must be produced using a more systematic approach and design.

• 대한방사선기술학회지:방사선기술과학
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• 제42권6호
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• pp.483-489
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• 2019

This paper obtained and compared these dose values by setting and comparing the X-ray imaging conditions (tube voltage 60 kVp, 70 kVp, 80 kVp, tube current 10 mAs, 16 mAs and X-ray field size are 10 × 10 cm, 15 × 15 cm). Each dose value was measure 10 times and represented as an average value. The purpose of this experiment is to serve as a reference for the X-ray exposure of diagnostic areas according to the type of dosimeter and to help with another dose measurement. The results of the experiment showed very little difference between the glass dosimeter(GD) and semiconductor dosimeter values due to changes in tube voltage of 60, 70, 80 kVp, regardless of field sized, but for dose area product(DAP), the difference in dose value was significant according to field size.

• 대한방사선기술학회지:방사선기술과학
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• 제27권4호
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• pp.23-29
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• 2004

진단영역에서 사용하는 넓은 선속 X선 에너지에 대한 차폐물질의 투과 특성을 Archer의 수학적 모델을 적용하여 나타내었다. 인버터 방식의 고전압발생장치를 사용하는 X선 발생장치를 사용하여 관전압 60 kVp부터 140 kVp까지의 범위에서 납, 철, 콘크리트, 유리등의 차폐체의 투과 특성을 나타내었다. 이러한 인버터 방식의 고전압발생장치를 사용하는 진단영방사선발생장치의 관전압별 투과도는 진단방사선발생장치를 사용하는 작업공간에서의 차폐 설계 시 차폐물질의 종류와 두께의 설정에 도움이 될 것이다.

• Journal of Radiation Protection and Research
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• 제47권1호
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• pp.39-49
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• 2022

Background: For proper monitoring of the eye lens dose, an appropriate calibration factor of a dosimeter and information about the mean energies of X-rays are indispensable. The scattered X-ray energy spectra should be well characterized in medical practices where eye lenses of medical staffs might be high. Materials and Methods: Scattered X-ray energy spectra were experimentally derived for three different types of X-ray diagnostic and therapeutic equipment, i.e., the computed tomography (CT) scan, the angiography and the fluoroscopy. A commercially available CdZnTe (CZT) spectrometer with a lead collimator was employed for the measurement of scattered X-rays, which was performed in the usual manner. Results and Discussion: From the obtained energy spectra, the mean energies of the scattered X-rays lied between 40 and 60 keV. This also agreed with that obtained by the conventional half value layer method. Conclusion: The scattered X-rays to which medical workers may be exposed in the region around the eyes were characterized by means of spectrometry. The obtained mean energies of the scattered X-rays were found to match the flat region of the dosimeter response.

• 대한디지털의료영상학회논문지
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• 제11권1호
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• pp.5-13
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• 2009

There are several reasons to take X-ray in case of inpatients. Some of them who cannot ambulate or have any risk if move are taken portable X-ray at their wards. Usually, in this case, many other people-patients unneeded X-ray test, family, hospital workers etc-are indirectly exposed to X-ray by scatter ray. For that reason I try to be aware of free space scatter dose accurately and make the point at issue of portable X-ray better in this study. kVp dose meter is used for efficiency management of portable X-ray equipment. Mobile X-ray equipment, ionization chamber, electrometer, solid water phantom are used for measuring of free space scatter dose. First of all the same surroundings condition is made as taken real portable X-ray, inquired amount of X-ray both chest AP and abdomen AP most frequently examined and measured scatter ray distribution of two tests individually changing distance. In the result of measuring horizontal distribution with condition of chest AP it is found that the mAs is decreased as law of distance reverse square but no showed mAs change according to direction. Vertical distribution showed the mAs slightly higher than horizontal distribution but it isnt found out statistical characteristic. In abdomen AP, compare with chest AP, free space scatter dose is as higher as five-hundred times and horizontal, vertical distribution are quite similar to chest AP in result. In portable X-ray test, in order to reduce the secondary exposure by free space scatter dose first, cut down unnecessary portable order the second, set up the specific area at individual ward for the test the third, when moving to a ward for the X-ray test prepare a portable shielding screen. The last, expose about 2m apart from patients if unable to do above three ways.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.126-126
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• 2009

X-ray high-voltage generator is the most important part that can decide the radiation exposure dose affecting a patient or operator according to the characteristic. If decrease of X-ray radiation exposure dose and output characteristic of high-voltage generator is unstable, a patient or operator must be exposed to more radiation. This study measures and analyzes the exposure dose reproducibility and output characteristic according to a change of tube current on the various rectification methods of diagnostic X-ray equipment. It can find that quality bastardize and output is increased if voltage of X-ray tube is increased. Exposure dose reproducibility according to output of X-ray equipment is extremely excellent in inverter type, and is stable in order of following three-phase, a single-phase and condenser method. This study can find that the reply incidence of high-voltage generator is generated due to difference in rectification method, noise occurs in X-ray due to that, quality of an image is decreased due to that, and medical diagnosis can be failed due to that.

• 한국의학물리학회지:의학물리
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• 제27권4호
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• pp.272-276
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• 2016

To investigate the optimum x-ray tube design for the dental radiology, factors affecting x-ray beam characteristics such as tungsten target thickness and anode angle were evaluated. Another goal of the study was to addresses the anode heel effect and off-axis spectra for different target angles. MCNPX has been utilized to simulate the diagnostic x-ray tube with the aim of predicting optimum target angle and angular distribution of x-ray intensity around the x-ray target. For simulation of x-ray spectra, MCNPX was run in photon and electron using default values for PHYS:P and PHYS:E cards to enable full electron and photon transport. The x-ray tube consists of an evacuated 1 mm alumina envelope containing a tungsten anode embedded in a copper part. The envelope is encased in lead shield with an opening window. MCNPX simulations were run for x-ray tube potentials of 70 kV. A monoenergetic electron source at the distance of 2 cm from the anode surface was considered. The electron beam diameter was 0.3 mm striking on the focal spot. In this work, the optimum thickness of tungsten target was $3{\mu}m$ for the 70 kV electron potential. To determine the angle with the highest photon intensity per initial electron striking on the target, the x-ray intensity per initial electron was calculated for different tungsten target angles. The optimum anode angle based only on x-ray beam flatness was 35 degree. It should be mentioned that there is a considerable trade-off between anode angle which determines the focal spot size and geometric penumbra. The optimized thickness of a target material was calculated to maximize the x-ray intensity produced from a tungsten target materials for a 70 keV electron energy. Our results also showed that the anode angle has an influencing effect on heel effect and beam intensity across the beam.

• Journal of Chest Surgery
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• 제31권7호
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• pp.730-734
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• 1998

배경: 기흉 환자를 수술하기 전에 폐기포의 위치, 숫자, 크기와 모양을 파악하기 위하여 단순 흉부 X선 사진이나 흉부 컴퓨터 단층 촬영등을 이용한다. 단순 흉부 X선 사진은 간편하고 저렴하나 정확도가 낮고, 흉부 컴퓨터 단층 촬영은 정확하나 비용이 많이든다. 그러나 흉강조영술을 이용하면, 폐기포의 상태를 비교적 저렴하고 정확히 파악할수 있으리라 예상되어, 이를 확인하기 위하여 본 임상 실험을 계획하였다. 대상 및 방법: 대상은 개흉이나 흉강내시경을 이용하여 폐기포 절제를 시행한, 원발성 자연 기흉 환자 22명이었다. 수술전에 단순 흉부 X선 사진과 흉강조영술을 시행하여, 이를 수술시의 폐기포의 소견과 비교하였다. 결과: 흉강조영술의 Sensitivity는 75%로 단순 흉부 X선 사진의 30%에 비하여 높았고, 정확도(Accuracy)도 72.7%로 단순 흉부 X선 사진의 36.4%에 비하여 높았다. 그러나 Specificity는 흉강조영술이 50%로 단순 흉부 X선 사진의 100%에 비하여 낮았다. 검사로인한 합병증은 없었다. 결론: 결론적으로 기흉의 수술전 검사로서 흉강조영술은 단순 흉부 X선 사진에 비하여 높은 진단적 가치를 지녔으며, 안전하게 이용될 수 있으리라 생각된다.