• Title/Summary/Keyword: Half Value alyer

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A Study on the Image Quality of Mammography and the Average Glandular Dose (맘모그래피의 화질과 평균유선조직선량에 관한 검토)

  • Lee, In-Ja;Kim, Hak-Sung;Kim, Sung-Soo;Huh, Joon
    • Journal of radiological science and technology
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    • v.25 no.2
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    • pp.47-55
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    • 2002
  • We came to the following conclusion as the results of experiment on the image quality of mammography and the average glandular dose using 4 apparatuses at 3 hospitals in Seoul. 1. Whereas the measurement of half value layer showed no differences among the apparatuses, the measurement by an attenuation curve method showed some differences by 5.9%. There were 9.1% differences in the measurement by aluminum conversion method. 2. The basic density of an automatic exposure control unit must be D = 1.40, but there was no automatic exposure unit adjusted precisely at any hospitals. The unit at the B hospital exceeded the allowable limit by ${\pm}0.15$. 3. In the photographing using an automatic exposure control unit and the management of an automatic film processor using a sensitometer, most automatic film processors were well kept. But in some cases the mean value of a fluctuation coefficient exceeded the allowable limit. There is a need for more cautious management. 4. The image quality of breast phantom photography was affected by the screen/film system among the hospitals. 5. The average glandular dose at a breast of 4.2 cm thickness depended on the tube voltage, In the case of Mo/Mo, it was measured $0.26{\sim}1.39\;mGy$ less than ACR standard 3.0 mGy.

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