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Title: Pseudomonoenergetic x-ray diffraction measurements using balanced filters for coherent-scatter computed tomography

Journal Article · · Medical Physics
DOI:https://doi.org/10.1118/1.3108394· OSTI ID:22100514
;  [1]
  1. Department of Medical Biophysics, Robarts Research Institute, and Lawson Health Research Institute, University of Western Ontario, 100 Perth Drive, London, Ontario N6A 5K8 (Canada)

Coherent-scatter computed tomography (CSCT) is a method of ''composition'' imaging based on measurements of diffraction patterns from tissues. Use of an x-ray tube degrades scatter pattern angular resolution due to the x-ray spectral width, making it difficult to uniquely identify some materials. The use of two transmission filters with similar atomic numbers (balanced ''Ross filters'') to generate pseudomonoenergetic scatter patterns is described as it applies to CSCT. An analysis of angular-blur mechanisms reveals that focal spot size and beam width are the most important factors determining Bragg-peak width when Er-Tm filters are used. A relative RMS spectral width of 1% can be achieved in the difference spectrum and a Bragg-peak RMS angular width of approximately 0.14 deg. (relative width of 3% at 5 deg. scatter angle) can be achieved with an effective energy of 58 keV.

OSTI ID:
22100514
Journal Information:
Medical Physics, Vol. 36, Issue 5; Other Information: (c) 2009 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
Country of Publication:
United States
Language:
English