Development of dosimetry using detectors of diagnostic digital radiography systems
- Graduate School of Environmental Studies, Nagoya University and Nagoya Daini Red Cross Hospital, 466-8650, Nagoya (Japan)
Dosimetry using an imaging plate (IP) of computed radiography (CR) systems was developed for quality control of output of the x-ray equipment. Sensitivity index, or the S number, of the CR systems was used for estimating exposure dose under the routine condition: exposure dose from 1.0 to 1.0x10{sup 2} {mu}C kg{sup -1}, tube voltages from 50 to 120 kV, and added filtration from 0 to 4.0 mm Al. The IP was calibrated by using a 6 cc ionization chamber having traceability to the National Standard Ionization Chamber. The uncertainty concerning the fading effect was suppressed less than 1.9% by reading the latent image 4 min{+-}5 s after irradiation at the room temperature 25.9{+-}1.0 degree sign C. The S number decreased linearly on the logarithmic graph regardless of the beam quality as exposure dose increased. The relationship between the exposure dose (E) and the S number was fitted by the equation E=a{sup '}xS{sup -b}. The coefficient a{sup '} decreased when the added filtration and the tube voltage were increased. The coefficient b was 0.977{+-}0.007 in all beam qualities. The dosimetry using the IP and the equation can estimate the exposure dose in a range from 9.0x10{sup -2} to 5.0 {mu}C kg{sup -1} within an uncertainty of {+-}5% required by the Japanese Industry Standard. This dose range partially included the doses under routine condition. The doses between 1.0 and 1.0x10{sup 2} {mu}C kg{sup -1} under the routine condition can be shifted to the 5% region by using an absorber. The IP dosimetry is applicable to the quality control of the CR systems.
- OSTI ID:
- 20853906
- Journal Information:
- Medical Physics, Vol. 34, Issue 1; Other Information: DOI: 10.1118/1.2402911; (c) 2007 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
- Country of Publication:
- United States
- Language:
- English
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