• 대한방사선기술학회지:방사선기술과학
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• 제27권4호
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• pp.37-41
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• 2004

목 적 : 측정을 통한 장치의 성능관리 평가로 임상실무에서의 능력배양과 정확한 관전압, 조사시간, 출력선량을 측정하는 기술을 익히고 병원에서 사용 중인 간접촬영용 X-선 발생장치 성능현황을 파악하기 위함이다. 재료 및 방법 : 관전압, 조사시간, 출력선량 측정기를 이용하여 10개 대학병원 간접촬영용 X-선 발생장치(원내,외 각 10대)를 이용하였다. 결 과 : 관전압 정확도 시험 PAE 판정에 의해 부적합한 간접촬영기는 3대가 나왔으며, 조사시간의 정확도 시험에서는 2대, 또한 조사선량의 재현성 시험에서도 조사선량에 대한 변동계수를 계산한 결과 3대가 나왔다. 3가지 성능검사에서 원외(이동차량)의 부적합한 간접촬영기는 5대, 원내는 3대로 원외(이동차량)의 간접촬영기가 원내보다 부적합한 것이 높게 나타났다. 결 론 : 간접촬영기의 성능을 일정하게 유지함으로서 방사선 피폭경감, 화질관리, 재촬영 감소 등에 의해 환자에게 양질의 의료서비스를 제공할 수 있는 여건을 마련할 수 있을 것이다. 따라서 정기적인 성능검사가 필요하다고 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2482-2484
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• 2000

In this paper, we have developed an automated computer aided diagnostic (CAD) scheme by using artificial neural networks(ANN) on guantitative analysis of chest photofluorography. The first ANN performs the detection of suspicious regions in a low resolution image. This was trained specifically on the problem of detecting abnormal regions digitized chest photofluorography. The second space matching method was used to distinguish between normal and abnormal regions of interest(ROI). If the ratio of the number of abnormal ROI to the total number of all ROI in a chest image was greater than a specified threshold level, the image was classified as abnormal.

• 보험의학회지
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• 제7권1호
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• pp.170-179
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• 1988

A study on the change of cardiothoracic ratio by age calculated from photofluorography film of chest in a total of the 8,115 insureds was undertaken. The results were as follows: 1. The incidence of cardiothoracic ratio of high value increased gradually with age. 2. At the same build, the average cardiothoracic ratio increased gradually with age. 3. Larger the build index was, the incidence of higher cardiothoracic ratio increased. 4. It seemed that the change of cardiothoracic ratio by age was influenced mainly by age and build(the change of build by age) from $18{\sim}19$ to $40{\sim}49$ age group and by age itself in $50{\sim}59$ age group and over. 5. The average cardiothoracic ratio of $30{\sim}39$ age group in male or female was approximate to that of all ages group respectively.

• 보험의학회지
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• 제7권1호
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• pp.180-188
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• 1988

A study on the standard cardiothoracic ratio calculated from the photofluorography film of chest in a total of 8,030 insured persons(3,449 men and 4,581 women) was undertaken. The results were as follows: 1) The linear regression equations were formed from the 99% confidence ilmits of actually measured average cardiothoracic ratio by weight index. The cardiothoracic ratios by weight index estimated by above mentioned equations, namely theoretic values of cardiothoracic ratio, should be regarded as the standard cardiothoracic ratios. 2) It seems that the standard cardiothoracic ratio${\pm}10%$ deviation should be regarded as the normal limits of cardiothoracic ratio. 3) The tables of standard cardiothoracic ratio by weight index and the normal limits of cardiothoracic ratio by weight index were presented. 4) The average weight index and cardiothoracic ratio in all males and females were 0.993 and 43.3%, and 0.997 and 46.3% respectively. 5) In order to evaluate the cardiothoracic ratio more accurately, the establishment of the standard cardiothoracic ratio by build is considered to be reasonable.

• 보험의학회지
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• 제3권1호
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• pp.219-232
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• 1986

A study on establishment of normal range of cardiothoracic ratio calculated from photofluorography film of chest by age and sex in a total of the 6,598 insureds was undertaken. The results were as follows: 1. In male group, the frequency distribution of cardiothoracic ratio was skewed weakly to the right in second decade, symmetrical in third and fourth decade, and was skewed weakly to the left in fifth and sixth decade; in female group, it was skewed weakly to the left in second, third and fourth decade, and was skewed weakly to the right in fifth and sixth decade. 2. On assumption that normal range of cardiothoracic ratio should comprise about 85% of all cardiothoracic ratios in each age group of both sexes, the sites of deviation from mean value of cardiothoracic ratio corresponding to maximum and minimum cardiothoracic ratio in the range of about 85% above mentioned were detected by statistical method on the frequency distribution of log tranformed cardiothoracic ratio, and $M{\pm}1.3$ sindicating normal range of cardiothoracic ratio was determined. In male group, normal range of cardiothoracic ratio determined by statistical method is 35-45%, 40-50%, 40-50%, 40-50% and 40-50% succesively in order from second to sixth decade; in female group, 40-50%, 40-50%, 40-50%, 45-55% and 45-55%.

• 보험의학회지
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• 제2권1호
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• pp.152-181
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• 1985

A statistical analysis on the cardiothoracic ratio in insurance medicine was carried out for 5,200 insured persons who were medically examined including photofluorography of the chest at the Honam medical department, Dong Bang life insurance Company, Ltd from November, 1979 to August, 1984. The results were as follows: 1. The mean value of the cardiothoracic ratio in all of the insured was $44.2{\pm}4.3%$. The mean value of the cardiothoracic ratio was $43.1{\pm}4.1%$ in all males and $45.2{\pm}4.2%$ in all females, and the difference of the values between males and females showed statistical significance(P<0.001). In each age group, the mean value of the cardiothoracic ratios of female was higher than that of male without exception and the difference of the values between males and females showed statistical significance(P<0.001). The mean value of the cardiothoracic ratio showed gradual increase with age from the second to sixth decade in male(P<0.05 or 0.001 after fourth decade) and from the second to seventh decade in female(P<0.05 or 0.001 from the second to sixth decade). 2. Correlation between both sexes and among age groups relating to the cardiothoracic ratios of the insureds seen to be a physiological phenomenon of the cardiac size and should be considered on the rating of the cardiothoracic ratio. Based on the correlation above mentioned and an author's assumption that the incidence of normal and abnormal cardiothoracic ratios in each age group would show the same rate in male and female, author prepared a modified rating table from the existing table; in male group the existing rating table is used and in female group the ratings of 0, 30-50, 50-100 and 100-D are to calculate by the cardiothoracic ratio of 51%or under, 52-56%, 57-61% and 62% or over respectively in the age group below 39, by the cardiothoracic ratio of 52% or under, 53-57%, 58%-62% and 63% or over respectively in the age group of 40-49, by the cardiothoracic ratio of 53% or under, 54-58%, 59-63% and 64% or over respectively in the age group over 60. 3. The relative frequency distribution polygons of the cardiothoracic ratio of both sexes drawn in a pair on one coordinate plane revealed lying in juxtaposition each other horizontally and showed the shifting of females polygon to male's one toward the direction of greater value of the cardiothoracic ratio at a short distance which increased gradually with age. 4. The minimum cardiothoracic ratio was 31.2% and the maximum cardiothoracic ratio was 63.6% in all of the insured. 5. In each age group, no significant sex difference was found in the relative frequency distribution of ratings by the cardiothoracic ratios of 5,200 insureds by using the rating table modified by author, while significant sex difference was found by using the existing rating table.

• 대한방사선기술학회지:방사선기술과학
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• 제8권2호
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• pp.21-28
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• 1985

We serveyed the actual condition of business of the departments of radiology of 45 health conters (except 3) in the area of Seoul, Kyungki and Inchon from March, 1984 to November, 1984. The results are summarized as follows : 1. T.O. of the radiologic technologist is three persons in each health center of Seoul area, and one person in each one of Kyungki and Inchon area. P.O. is 2-5 persons in Seoul area, 1-2 persons in Kyungki or Inchon area. 2. The number of all the radiologic technologists employed now is 75 persons, and among all of them, when analized by position class 7th is 54.7%, class 8th 28.0%, class 9th is 13.3%, and class 6th is 2.7%, and by sex, female is 68.0%, male is 32.0%, by educational background, for the most part, junior college graduates come to 73.3%, by age group 60% of them is in their twenties, 16.0% is in their thirties and forties, 8.0% is in their fifties, and by career after certificate 60% have the career of 1-5 years, 13.3% have the one of 6-7 years or mor than 21 years, and 6.7% have the one of 11-15 years of 16-20 years. 3. All the diagnostic x-ray equipment being kept is 62, and among them flxing equipment is 71.0%, portable equipment is 29.0% and by rating of X-ray equipment, maximum tube current 100 mA is 46.8%, maximum KV 100KVP is 72.6%, the most part. 4. Photofluorographic camera and hood are equipped in every health center. While, as to the radiographic cassettes, $14{\times}14"$ cassetts are equipped in every health center, but cassettes of other sizes are in half of them. 5. Bucky's table is equipped in 11.9% health centers, the automatic processor is in 21.4%, the photofluorographic film changer is 9.5%, the grid is 73.8%, the protective apron is in 88.1%, and the protective glove is in 57.1% health centers. 6. The number of the people who got the x-ray examination for one year (by the year 1989) is the most, 1,000-6,000 in direct radiography of the chest, or 15,0001-45,000 in the health centers of Seoul area, 5,000-20,000 in Kyungki and Inchon area in photofluorography of the chest. Moreover, other radiographies are being taken extremely limitedly in all health centers. 7. In processing types of x-ray film, automatic processing is used in 9 health centers (21.4%), manual tank processing is in 30 (71.4%), and manual tray processing in 3 (7.2%). 8. As for collimation of x-ray exposure field, "continual using restricted by a subject size" has the most part, 78.6% "restricted using at every radiography" has 19%, and the case of "never considered" has 2.4% response. 9. As for the dosimeter used for radiation control, film badge (35.7%) and pocket dosimeter (26.2%) are used, and in 38.1% health centers the dosimeter is not equipped at all. Consideration of the previous radiation exposure is being done in only one health center. 10. Reading of radiographs is mainly depended on the radiologists electively (45.2%) or on the genral practitioners(45.2%).