• 제목/요약/키워드: Scattered dose of X-ray

검색결과 66건 처리시간 0.023초

일반엑스선영상검사의 인자에 따른 산란방사선량 평가 및 분석 (Evaluation and Analysis of Scattered Radiation Dose according to Factors in General X-ray Examination)

  • 정동경;박명환;서정민
    • 대한방사선기술학회지:방사선기술과학
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    • 제47권1호
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    • pp.13-19
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    • 2024
  • Control of scattered radiation is one of very important factors in the use of medical radiation. In general X-ray exam, the causes, measurement methods, and the kind of detectors of scattered rays within the radiation area are diverse. In this study, the dose of scattered ray was measured by changing the thickness of the polycarbonate phantom and the tube voltage. As a result of measurement of scattered radiation, the results show that the scattered dose significantly(p<.05) increased with growing of thickness of phantom in the tube voltage 40, 50 and 60 kVp(F(p)<.05, R2>64%). As tube voltage increased at all phantom thicknesses, the scattered dose also significantly(p<.05) increased(F(p)<.05, R2>69%). In cases where a significant correlation was shown, the coefficient of determination of more than 60% was shown in regression analysis. The results of this study can be used as data on scattered radiation dose according to the tube voltage and the object thickness in general X-ray imaging exam.

이동용 치과 X선 발생장치의 누설 및 산란 선량에 관한 연구 (Leakage and scattered radiation from hand-held dental x-ray unit)

  • 김은경
    • Imaging Science in Dentistry
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    • 제37권2호
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    • pp.65-68
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    • 2007
  • Purpose: To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. Materials and Methods: For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR III was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of handheld dental X-ray unit were 70 kVp, 3 mA, 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. Results: The mean dose at the hand level when human skull DXTTR III was exposed with portable X-ray unit $6.39{\mu}Gy$, and the mean dose with fixed X-ray unit $3.03{\mu}Gy$ (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was $2.97{\mu}Gy$ and with fixed X-ray unit the mean dose was $0.68{\mu}Gy$ (p<0.01). Conclusions: The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

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X선 촬영에서 조사야 크기에 따른 산란선량의 변화 (Change of the Scattered Dose by Field Size in X-ray Radiography)

  • 최성관
    • 한국콘텐츠학회논문지
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    • 제13권3호
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    • pp.198-203
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    • 2013
  • 본 연구에서는 손, 머리, 복부 등에 대한 X선 촬영 시행 시 조사야 크기를 최적화할 경우와 최대화할 경우 검사목적부위로부터 30cm 거리에서의 X선 산란선량이 각각 어느 정도인지를 알아보았다. 그 결과 손, 머리, 복부 등에 대한 X선 산란선량은 첫째, 소인촬영의 경우 조사야 크기를 최적화하였을 때 각각 $0.08{\mu}Sv$, $4.39{\mu}Sv$, $5.56{\mu}Sv$로 나타났고, 조사야 크기를 최대화하였을 때 각각 $0.58{\mu}Sv$, $33.47{\mu}Sv$, $35.93{\mu}Sv$로 나타났으며, 둘째, 성인촬영의 경우 조사야 크기를 최적화하였을 때 각각 $0.40{\mu}Sv$, $14.51{\mu}Sv$, $18.86{\mu}Sv$로 나타났고, 조사야 크기를 최대화하였을 때 각각 $2.78{\mu}Sv$, $107.40{\mu}Sv$, $117.52{\mu}Sv$로 나타났다(P<0.001). 결론적으로, X선 촬영 시 조사야 크기를 필요한 만큼만으로 최대한 줄여주어 최적화시켰을 때에 최대화 시켰을 때보다 피사체 주변의 X선 산란선 발생량은 약 6~7배 정도 감소하였다.

Experimental Evaluation of Scattered X-Ray Spectra due to X-Ray Therapeutic and Diagnosis Equipment for Eye Lens Dosimetry of Medical Staff

  • Kowatari, Munehiko;Nagamoto, Keisuke;Nakagami, Koich;Tanimura, Yoshihiko;Moritake, Takashi;Kunugita, Naoki
    • 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.

X선촬영시(線撮影時) 연부조직(軟部組織) 두께에 따른 선량분포(線量分布)에 관(關)한 연구(硏究) (A Study on the Distribution of X-ray according to the Thickness of Soft Tissue in Radiography)

  • 박성옥
    • 대한방사선기술학회지:방사선기술과학
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    • 제11권2호
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    • pp.3-15
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    • 1988
  • When X-rays were projected into a patient, there occured the phenomena such as penetration, absorption and scattering etc. The penetrating rays were recorded on films as X-ray image used for diagnosis but scattered rays caused the radiation hazard both to the patient, specialist and technicians. The soft tissue includes many organs which are sensitive to the radiation and in may occupy $40{\sim}50%$ of body weight. Therefore X-rays should be carefully projected to the patient and it is strongly recommended to analyse the distribution of X-rays, when ever the patient is exposed to X-rays. In this study, the distribution of X-ray according to the thickness, the radiation field and the tube voltages (kVp) in soft tissue, the following results were obtained: 1. Total transmitted rays which kept the step with X-ray tube voltage (kVp) increased in proportion to the increasing of X-ray tube voltage. 2. The scattered ray rate in the total transmitted ray was not significantly found with X-ray tube voltage. 3. The affecting factors of the scattered ray rate in total transmitted ray were shown through the radiation field and the thickness. 4. The dose of scattered ray by the angle was observed more in direction of primary ray ($0^{\circ}$) and back scattering ($160^{\circ}$) than in direction of $90^{\circ}$. 5. The more the distance from phantom to the patient should be less distribution of scattered ray.

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이동형 X선촬영에서 공간산란선량 분포 측정 (Measurement of the Scattered Spatial Dose Distribution for the Mobile X-ray Radiography)

  • 권덕문;박명환;남효덕
    • 대한방사선기술학회지:방사선기술과학
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    • 제24권1호
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    • pp.23-26
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    • 2001
  • The spatial distribution of the scattered dose for mobile X-ray radiography is measured. The scattered X-ray exposures at the radius of 50, 100 and 150 cm from the irradiation center are 880, 180 and $50\;{\mu}R$, respectively. This scattered X-rays can be reduced to 60% by inserting the portable shield made by 0.4 mm copper sheet sandwiched in two plywoods.

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두꺼운 피사체 X선 촬영 시 보호앞치마 착용의 유용성 (Utility of Wearing Protective Apron for X-ray of Thick Subject)

  • 최성관;동경래
    • 방사선산업학회지
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    • 제11권3호
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    • pp.167-171
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    • 2017
  • This study examined the effectiveness degree of a protective apron that is taken not to be exposed to the first ray or scattered rays, for X-ray of thick subject like lateral lumbar, and the results are as follows; First, spatial dose by scattered rays is shielded by 3 mmPb protective apron, 86.8% at a distance of 50 cm, 92.7% at 100 cm, and 95.6% at 200 cm, when minimizing the field size, while 89% at a distance of 50 cm, 92.3% at 100 cm, and 95.2% at 200 cm, when maximizing the field size. Second, 1st exposure dose is shielded by 3 mmPb protective apron, 93.7% at a distance of 50 cm, 94.4% at 100 cm, and 93.6% at 200 cm, when minimizing the field size, while 93.7% at a distance of 50 cm, 93.6% at 100 cm, and 94.2% at 200 cm, when maximizing the field size.

엑스선 촬영실의 공간산란선 발생 인자에 관한 연구 (A Study on the Factors of Spatial Scattered Ray Occurrence in the X-ray Radiography Room)

  • 나수경;한상효
    • 대한방사선기술학회지:방사선기술과학
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    • 제32권4호
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    • pp.393-399
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    • 2009
  • 본 연구에서는 전리함을 이용하여 엑스선 촬영실 내에서 공간산란선량을 측정하고 산란선의 발생원과 조사 조건에 대한 산란율 의존성을 조사하였다. 아크릴 팬톰의 산란선 발생 인자를 조사하기 위해 관전압(40~140 kV)과 조사면($10{\times}10\;cm^2$, $20{\times}20\;cm^2$, $35{\times}35\;cm^2$)에 대한 산란율 변화를 측정하였다. 조사면이 $35{\times}35\;cm^2$일 때 측방산란율은 3.11~4.5%로 측정되었다. 촬영실 내에서 팬톰, 콜리메이터, 엑스선관, 벽면에서 발생하는 산란선량의 영향을 측정하였는데 전체 관전압에 대해 팬톰의 산란선 발생률은 95.4% 이상이었으며 콜리메이터, 엑스선관, 벽면의 산란선 발생률은 각각 2.6%, 1.3%, 0.7% 이하로 나타났다. 관전압 100 kV, 40 mAs 조사 조건에서 촬영실 내 팬톰으로부터 1 m 거리에서 측정한 공간선량은 최대 2 mR 정도로 나타나 조사조건의 최적화 등의 산란선 경감조치가 필요할 것으로 생각된다.

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흉부X선촬영시(胸部X線撮影時) 산란선(散亂線)이 화질(畵質)과 피폭선량(被曝線量)에 미치는 영향(影響) (Effects of the Scattered Radiation on Image Quality and Exposure Dose in Chest Radiography)

  • 반야유;임태랑;석전유치;전전미향;앵정달야;이만구;안봉선;김정민
    • 대한방사선기술학회지:방사선기술과학
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    • 제16권2호
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    • pp.27-38
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    • 1993
  • To investigate relationships between image guality and exposure dose, Chest X-ray films were evaluated for the following points:how much scattered radiation can affect reduction in image quality and can be permissible diagnostically? For this purpose using a test charts and Burger's phantoms. The visual evaluation of their X-ray films and the measurements of scattered radiation were carried out. The dose of scattered radiation ranging from 20 to 25% was found to be for nothing in any diagnostic obstacle. In this range, surface doses were low of 17, 21, and $25{\mu}Gy$ for The thickness of the chest of 15, 20 and 25 cm respectively. Comparison of these high voltage X-ray films with low voltage ones showed a surface dose rate of 1:11.7. Therefore, X-ray quality, photosensitive materials(film and screen) and grid should be selected very carefully for the purpose of reduction in exposure dose.

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이동형 X선 발생장치의 2차 방사선 차폐를 위한 선속조절기 개발 연구 (Development of Radiation Restrictor for Secondary Radiation Shielding of Mobile X-ray Generator)

  • 구본열;김가중
    • 대한방사선기술학회지:방사선기술과학
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    • 제41권5호
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    • pp.397-403
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    • 2018
  • Mobile X-ray generators are used not in the radiation area but in open space, which causes the exposure of secondary radiation to the healthcare professionals, patients, guardians, etc., regardless of their intentions. This study aimed to investigate the shielding effect of the developed radiation restrictor to block the secondary radiation scattered during the use of mobile X-ray generator. Upon setting the condition of mobile X-ray generator with chest AP, spatial doses were measured by the existence of human equivalent phantom and radiation restrictor, and measured by the existences of phantom and radiation restrictor at the same length of 100 cm. Measurements were taken at intervals of 10 cm every $30^{\circ}$ from $-90^{\circ}$ (head direction) to $+90^{\circ}$ (body direction). Upon the study results, spatial doses in all direction were increased by 45% on average when using phantom in the same condition, however, they were decreased by 64% on average when using the developed radiation restrictor. The dose at 100 cm from the center of X-ray was $3.0{\pm}0.08{\mu}Gy$ without phantom and was increased by 40% with $4.2{\pm}0.08{\mu}Gy$ after phantom usage. The dose when using phantom and the developed radiation restrictor was $1.4{\pm}0.08{\mu}Gy$, which was decreased by 66% compared to the case without using them. Therefore, it is considered the scattered radiation can be shielded at 100-150 cm, the regulation of the distance between beds, effectively with the developed radiation restrictor when using mobile X-ray generators, which can lower the radiation exposure to the people nearby including healthcare professionals and patients.