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Title: Minimizing image noise in on-board CT reconstruction using both kilovoltage and megavoltage beam projections

Journal Article · · Medical Physics
DOI:https://doi.org/10.1118/1.2768862· OSTI ID:21032703
;  [1]
  1. Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

We studied a recently proposed aggregated CT reconstruction technique which combines the complementary advantages of kilovoltage (kV) and megavoltage (MV) x-ray imaging. Various phantoms were imaged to study the effects of beam orientations and geometry of the imaging object on image quality of reconstructed CT. It was shown that the quality of aggregated CT was correlated with both kV and MV beam orientations and the degree of this correlation depended upon the geometry of the imaging object. The results indicated that the optimal orientations were those when kV beams pass through the thinner portion and MV beams pass through the thicker portion of the imaging object. A special preprocessing procedure was also developed to perform contrast conversions between kV and MV information prior to image reconstruction. The performance of two reconstruction methods, one filtered backprojection method and one iterative method, were compared. The effects of projection number, beam truncation, and contrast conversion on the CT image quality were investigated.

OSTI ID:
21032703
Journal Information:
Medical Physics, Vol. 34, Issue 9; Other Information: DOI: 10.1118/1.2768862; (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