Abstract
The measurement of the FWHM of the slice thickness radiation dose profile of a CT scanner using a prototype low sensitivity CR imaging plate has been investigated, as an alternative to the traditional method using envelope-packed industrial film. Using a standard Agfa clinical CR system to acquire the image, the FWHM of the dose profile can be accurately measured using readily available Public Domain software. An Agfa 18 × 24 cm CR cassette gives a pixel pitch of 113.5 μm, but with interpolation, the measurement accuracy can be less than 1 pixel. For a nominal 10 mm collimation, 15 successive measurements of the FWHM using CR gave an average width of 10.00 mm with a standard deviation of 0.02 mm. This may be compared with 4 successive measurements using film and a dual exposure technique to define the optical density at half peak height, yielding an average width of 9.98 mm with a SD of 0.03 mm. This prototype NDT plate is not a commercial product, but a radiotherapy plate with a similar sensitivity is available commercially and should give similar results.
Similar content being viewed by others
References
AAPM Report No. 39,Specification and Acceptance Testing of Computed Tomography Scanners, Published for the American Association of Physicists in Medicine by the American Institute of Physics, May 1993.
Image J, W. Rasband, National Institutes of Health, USA, Public Domain software, http://rsb.info.nih.gov/ij/
Transpos.exe, P. N. Schweitzer, US Geological Survey, Reston, VA 20192, http://geochange.er.usgs.gov/pub/tools/ transpose/README.html
AAPM Report No. 74,Quality Control in Diagnostic Radiology, Published for the American Association of Physicists in Medicine by Medical Physics Publishing, July 2002.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Thomson, F.J. Measurement of CT scanner dose profiles in a filmless department. Australas. Phys. Eng. Sci. Med. 28, 179 (2005). https://doi.org/10.1007/BF03178713
Received:
Accepted:
DOI: https://doi.org/10.1007/BF03178713