Energy-resolved Compton scatter estimation for micro-CT

Type of content
Conference Contributions - Published
Publisher's DOI/URI
Thesis discipline
Degree name
Publisher
University of Canterbury. Electrical and Computer Engineering
University of Canterbury. Human Interface Technology Laboratory
Journal Title
Journal ISSN
Volume Title
Language
Date
2012
Authors
Opie, A.M.T.
Butler, A.P.H.
Bones, P.J.
Abstract

X-ray scatter can cause significant distortion in CT imaging especially with the move to cone-beam geometries. Incoherent scatter (Compton scatter) is known to reduce the energy of scattered photons according to the angle of the scattering. The emergence of energy-resolved x-ray detectors offers an opportunity to produce and apply more accurate scatter estimates leading to improved image quality. We have developed a scatter estimation algorithm that accounts for the variation in scatter with incident radiation energy. Where existing methods generate estimates of scatter for the complete detected energy band, our new method produces separate estimates for each of the energy bands that are measured allowing a more focused correction of scatter. Our method is intended to be used in an iterative compensation framework like that of Ruhrnschopf and Klingenbeck (2011); it calculates the scatter contribution to each energy bin used in a scan based on the current volume estimate. Comparisons with Monte Carlo simulations indicate that this algorithm is effective at estimating the scatter level in separate energy bins. We found that the amount of scatter that loses enough energy to hop between energy bands is small enough to neglect but that scatter intensity is dependent on the incident energy so application of a spectrally-aware compensation technique is valuable.

Description
Citation
Opie, A.M.T., Butler, A.P.H., Bones, P.J. (2012) Energy-resolved Compton scatter estimation for micro-CT. San Diego, CA, USA: Developments in X-Ray Tomography VIII, 13-15 Aug 2012. Proceedings of the SPIE, 8506, 850616.
Keywords
Compton, scatter, estimation, spectral, micro-CT, energy-resolved
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Field of Research::11 - Medical and Health Sciences::1103 - Clinical Sciences::110320 - Radiology and Organ Imaging
Fields of Research::32 - Biomedical and clinical sciences::3206 - Medical biotechnology::320602 - Medical biotechnology diagnostics (incl. biosensors)
Fields of Research::51 - Physical sciences::5105 - Medical and biological physics::510502 - Medical physics
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Copyright 2012 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.