• 대한방사선기술학회지:방사선기술과학
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• 제15권2호
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• pp.17-23
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• 1992

Simple chest radiography is the most frequently performed examination in radiologic practice. However, with transmitted dose through chest which has the problem of wide variations in absorption, conventional Film/Screen Combinations Method make it difficult to delineate lung field mediastinum & cardia portion and subdiaphragmatic structures. In order to overcome this problem, we have been tried several methods as follows. High Kilovoltage Technique, Rare Earth Screen/Wide Lattitude Film, Use of Compensating Filter and Digital Beam Attenuator and recently Insigh System has been developed. In this paper, we'd like to discuss Insight film through apperciation by measuring the difference of contrast. In order to evaluate insight film. We have done experiments using Insight System with Simple Phase, Picker 550. We could get an result which was able to overcome the limitted dynamic range of conventional Film/Screen System remarkably.

• 대한디지털의료영상학회논문지
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• 제12권2호
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• pp.89-95
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• 2010

High contrast and high resolution are the most important factors for examining mammography images. Despite of the inconveniences of screen-film, most clinics still prefer them to computed radiography(CR) and direct radiography(DR). The reading of screen-film mammography images is influenced by the brightness from the X-ray illuminator, the exam room and incoming light from outside sources. Therefore, a comparative analysis on the results of mammo phantom images would be variated by the changes in the reading environment. There was no influence on reading results from the examiners close distance eyesight(p > 0.05); however, reading of micro lesions improved with greater darkness in the X-ray film reading room and the brightness of the X-ray illuminator(p < 0.05). Also, observation of fiber and mass images were maximized at a distance of 50 cm from the reader. Now, it is possible to observe these small classification groups using a magnifying glass without being physically close to the image. For the image of mammography, obtaining high quality images is important but in order to get an accurate clinical lesions of the reading also needs to be considered the optimal environmental factors.

• 한국방사선학회논문지
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• 제14권4호
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• pp.391-396
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• 2020

본 연구는 Gd₂O₂S:Tb 형광체 화합물을 사용하여 비파괴검사 중 방사선투과검사에 적용할 수 있는 형광체 증감지를 개발하였다. 또한 이러한 형광체 증감지를 FE-SEM, RMS 및 RDS 분석을 통해 형광체 증감지의 영상 균일도를 분석하였다. 또한, 응력-변형 특성 곡선 측정을 통해 Gd₂O₂S:Tb 형광체 스크린의 인장강도, 신장률 및 탄성계수를 평가하였다. 실험 결과, RSD 값이 평가 기준인 10% 이내로 우수한 영상균일도를 가지는 것으로 평가되었다. 또한, 물리적 특성 평가 결과, 인장 강도는 1.1760 N/㎟이며, 파단시 인장강도는 1.1515 N/㎟로 나타났다. 이러한 결과로부터 본 연구에서 제작된 상온 겔-프린팅 제조법을 이용하여 제작된 Gd₂O₂S:Tb 형광체 스크린은 방사선 투과검사용 디지털 방사선 검출기에 적용이 가능할 것으로 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제14권2호
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• pp.9-14
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• 1991

Chest radiograms obtained by using Fuji Computed Radiography(FCR) system were compared to conventional film/screen radiograms. The FCR images showed better image quality in diagnostic informations than the conventional chest images. In FCR, the radiation exposure to patient for chest examination could be reduced up to one tenths of conventional chest examination. The main advantages or FCR were considered to depend on the contrast processing and frequency processing properties. The use of FCR in clinical work may improve both diagnostic quality and radiation exposure.

• 대한방사선협회지
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• 제27권2호
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• pp.22-34
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• 2001

DR은 방사선과 뿐만 아니라 병원전체의 생산성 및 업무의 효율성에서 중요한 요소로 자리잡아가고 있다. DR환경은 CR보다 다양한 Parameter를 가지고 있어 양질의 의료서비스 제공이 가능하다. 현재 각 병원의 방사선과는 Film-Screen system에서 Full-PACS를 통한 DR 환경으로 변화하고 있다. Full- PACS를 사용하고 있는 본원에서는 DR환경에서의 일반촬영 System중 CR과 DDR의 최적노출조건과 그에 따른 Image qu

• 대한방사선기술학회지:방사선기술과학
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• 제20권2호
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• pp.56-62
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• 1997

To evaluated the image quality and the patient exposure for the chest radiography, its fundamental imaging properties were investigated. The basic imaging properties were evaluated by measuring characteristic curves, relative speeds, average gradient, and patient exposure dose. The image qualities were evaluated by using a rotating meter. It was found that the film gradient of SRO750/SRH system was 3.13 and that of SRO750/HR-C30 was 1.77. The ratio of SRO1000/TMH to FS/RP-1 was 1 to 18.2. It was possible to visualize the static image when the exposure time was less than 2.5 msec in patient that had respiratory excessive motion, heart beat and natural physical motion, and less than 8.5 msec in normal. The ratio of medical exposure dose compared with our method was 1 to 25 in the routine chest radiography and maximum was 1 to 70. In estimation of the image quality in same cases, we found that the image of SRO1000/SRH and TMH of super sensitive systems was the same results. We found that these super sensitive screen-film systems were available for the chest radiography considering the relationship between the image quality and patient exposure.

• 대한방사선기술학회지:방사선기술과학
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• 제22권1호
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• pp.13-20
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• 1999

This study is to calculate the exposed radiation dose using Bit method, NDD calculation method and monogram method without dosimeter. In addition, we can calculate the radiation dose from x-ray film density as a film badge. The authors examined the entrance skin dose from $2{\sim}3$ intercostal chest x-ray film density. We also studied the relationship between film density and equivalent dose in the each screen film system under the different radiation quality and the poor geometry condition of grid ratio. As results, we established the deductive method to define the entrance skindose from chest x-ray film density. The error range was found in the range $-13%{\sim}+l7%$ for between deductive entrance skindose and the $2{\sim}3$ intercostal chest x-ray film density to actual detective radiation dose with dosimeter.

• 한국임상수의학회지
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• 제27권3호
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• pp.284-288
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• 2010

이 연구의 목적은 개에서 실험적으로 복수를 유발한 후, 컴퓨터 촬영술과 필름 촬영술을 실시하여 복수의 정량적인 비교를 한 것이다. 건강한 4 마리의 비글견과 1 마리의 말티즈 견을 사용하였으며, 각 개체마다 무균적으로 복강 내로 멸균 생리 식염수를 6 ml, 8 ml, 12 ml, 15 ml, 그리고 18 ml 을 주입하였으며, 우외측상과 복배상으로 컴퓨터 촬영과 필름 촬영을 실시하였다. 총 5명의 평가자에게 복수량에 따른 컴퓨터 촬영 사진과 필름 촬영 사진을 보였주었으며, 각 사진마다 복수량에 따라 5 가지의 점수를 순차적으로 평가하도록 하였다 (0 =복수 없음, 5 =중등도의 복수가 있음). 5명의 평가자가 평가한 데이터를 이용하여 ROC 분석 방법을 이용하여, 두 진단 모델간의 민감도와 특이도를 평가하였다. 이 연구를 통해, 복수의 양을 평가하는데 있어 두 진단 모델간의 유의적인 차이는 보이지 않았다. 그러나 RCO 분석 방법을 통해, 컴퓨터 촬영술이 필름 촬영술에 비해 민감도가 상대적으로 높았으며, 각 평가자 간에도 복수의 양을 평가하는데 있어, 상대적으로 컴퓨터 촬영술이 우위인 것을 알 수 있었다.

• 대한방사선기술학회지:방사선기술과학
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• 제20권2호
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• pp.49-55
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• 1997

This study was carried out to investigate radiographical and operating conditions of X-ray units and exposure doses to patients during chest radiography, so that the results could provide basic data used for reducing the exposure dose and for providing the diagnostic information with better quality. The conditions and exposure doses of 100 X-ray units mainly used for chest radiography were examined and also 100 radiological technologists mainly handling those apparatus at 76 medical facilities in Pusan were surveyed using a questionnaire from October 1 to December 31 in 1995. The following results were obtained from the study : 1. It was found that most units were capable of taking a high tube voltage radiography by showing 67% of the units equipped with the maximum tube voltage of 150 kV, 94% with more than 500 mA for the rating capacity and 85% with the full wave type of a signal phase. 2. For actual chest radiographical conditions, however, 80% of the units were operated at $60{\sim}100\;kVp$ and only 14% at 100 kVp and over for the high tube voltage. 3. The average exposure time was less than 0.1 second, and eighty four percent of the units adapted the X-ray tube currents ranging from 200 to 300 mA, 80% the focus-film distances between 180 and 210 cm, and 63% the focus sizes of more than 2.0 mm. 4. Most units(98%) employed additional filters made of aluminum, 75% the thickness of filters less than 2.0 mm, and only 2 units the compound filters. 5. Ortho chromatic system was only adopted in 13% of screen film system for the units, and 73% used the grid ratio at 8 : 1 for the low tube voltage during chest radiography. 6. The average exposure dose of all X-ray units during chest radiography was $371\;{\mu}Sv$ with a difference of about 16 times between the minimum to the maximum, and $386\;{\mu}Sv$ both at hospitals and at health centers, followed by $380\;{\mu}Sv$ at general hospitals and $263\;{\mu}Sv$ at university hospitals without showing any statistically significant differences. In conclusion, since patients during chest radiography at medical facilities in Pusan exposed to high levels of radiation, it is recommended that appropriate added filters and grids necessary for the high tube voltage radiography and high-speed screen systems should be adopted and used as soon as possible in order to reduce exposure dose to the patients.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.392-395
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• 2003

For the purpose of digital x-ray imaging, many materials such as $PbI_2$, $HgI_2$, TlBr, CdTe and CdZnTe have been under development for servaral years as direct converter layer. $Hgl_2$ film detector have recently been shown as one of the most promising semiconductor materials to be used as direct converters in x-ray digital radiography. This paper, the $HgI_2$ films are deposited on conductive-coated glass by screen printing, in which $HgI_2$ powder is embedded in a binder and solvent, and the slurry is used to coat the conductive-coated glass. We investigated electrical characteristic of the fabricated $HgI_2$ films. The x-ray response to radiological x-ray generator of 70Kvp using the current integration mode will be reported for screen printing films. These results indicate that $HgI_2$ detectors have high potential as new digital x-ray imaging devices for radiography.