Results 201 to 210 of about 166,547 (260)
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Absorbed Radiation Dose in Mammography
Radiology, 1979Radiation dose from mammographic techniques was determined as a function of surface exposure, beam quality, and depth. Relative exposure vs. depth was measured in tissue-substitute materials by thermoluminescent dosimetry. The f-factors were calculated from elemental compositions of mastectomy specimens. Dose at depth depends on beam quality as well as
G R, Hammerstein +5 more
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Average absorbed dose in thin absorbers
Physics in Medicine & Biology, 1974It is pointed out that an expression for the average absorbed dose for a monoenergetic beam, given in the ICRU report 17 (1970) is not formally correct. The error arises from assuming that partial attenuation coefficients can be treated in the same way as total attenuation coefficients.
null W D McDavid, null R G Waggener
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Absorbed Dose Tn Mammary Radiography
Acta Radiologica: Therapy, Physics, Biology, 1976By exposure measurements in an alcohol-water mixture simulating breast tissue, the absorbed dose, and dose distribution in the breast at the radiation qualities commonly used in mammary radiography have been calculated. The absorbed doses for different recording media have been compared at those radiation qualities which result in similar image ...
M, Karlsson +3 more
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Absorbed dose water calorimeter
Medical Physics, 1980Advantage was taken of the low thermal diffusivity of water and the imperviousness of polyethylene film to water to construct a calorimeter for directly measuring absorbed dose in that medium. An ultrasmall bead thermistor was sandwiched between two thin films stretched on polystyrene rings and immersed in an unregulated water bath.
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Calculated Absorbed Dose for Electrons
Radiation Research, 1964The object of this investigation is the theoretical calculation of depth-dose distributions arising from plane monodirectional and monoenergetic electron beams of energy 10 to 20 Mev incident on an infinite water medium. The starting point in the calculation of the rate of local energy absorption as a function of depth is the Lewis equation (1). It can
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The measurement of absorbed dose and dose gradients
Radiation Physics and Chemistry (1977), 1980Abstract The more reliable systems and procedures of dosimetry for radiation sterilization applications are described, along with sources of uncertainty and ways to achieve optimum accuracy and reproducibility. Dosimetry practice in production must be accompanied by correct methods of dosimeter calibration to achieve measurement assurance and quality
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The advantages of absorbed‐dose calibration factors
Medical Physics, 1992A formalism for clinical external beam dosimetry based on use of ion chamber absorbed‐dose calibration factors is outlined in the context and notation of the AAPM TG‐21 protocol. It is shown that basing clinical dosimetry on absorbed‐dose calibration factors ND leads to considerable simplification and reduced uncertainty in dose measurement. In keeping
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Transactions of the American Institute of Electrical Engineers. Part III: Power Apparatus and Systems, 1960
Equations and tabular data are presented for calculating the absorbed dose in rads when the field conditions of expcsure to radiation are known. The elements considered here are those most commonly found in low-Z organic materials, such as plastics, elastomers. lubricants, and insulating materials. The types of radiation considered are gamma radiation,
C. H. Cheek, V. J. Linnenbom
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Equations and tabular data are presented for calculating the absorbed dose in rads when the field conditions of expcsure to radiation are known. The elements considered here are those most commonly found in low-Z organic materials, such as plastics, elastomers. lubricants, and insulating materials. The types of radiation considered are gamma radiation,
C. H. Cheek, V. J. Linnenbom
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Physics in Medicine and Biology, 2000
Current clinical experience in radiation therapy is based upon dose computations that report the absorbed dose to water, even though the patient is not made of water but of many different types of tissue. While Monte Carlo dose calculation algorithms have the potential for higher dose accuracy, they usually transport particles in and compute the ...
J V, Siebers +3 more
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Current clinical experience in radiation therapy is based upon dose computations that report the absorbed dose to water, even though the patient is not made of water but of many different types of tissue. While Monte Carlo dose calculation algorithms have the potential for higher dose accuracy, they usually transport particles in and compute the ...
J V, Siebers +3 more
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Determination of the Absorbed Dose in Radiation Therapy
Radiology, 1958The adoption of basic energy units for the expression of the absorbed dose of radiation (1) makes desirable a means for determining absorbed dose in rads under conditions simulating clinical radiation therapy and in actual clinical therapy. The ferrous sulfate dosimeter provides a means for determining absorbed dose under the first of these conditions (
J R, ANDREWS +3 more
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