Comparison of methods for suppressing edge and aliasing artefacts in iterative x-ray CT reconstruction

Wojciech Zbijewski, Freek J. Beekman

Research output: Contribution to journalArticle

Abstract

X-ray CT images obtained with iterative reconstruction (IR) can be hampered by the so-called edge and aliasing artefacts, which appear as interference patterns and severe overshoots in the areas of sharp intensity transitions. Previously, we have demonstrated that these artefacts are caused by discretization errors during the projection simulation step in IR. Although these errors are inherent to IR, they can be adequately suppressed by reconstruction on an image grid that is finer than that typically used for analytical methods such as filtered back-projection. Two other methods that may prevent edge artefacts are: (i) smoothing the projections prior to reconstruction or (ii) using an image representation different from voxels; spherically symmetric Kaiser-Bessel functions are a frequently employed example of such a representation. In this paper, we compare reconstruction on a fine grid with the two above-mentioned alternative strategies for edge artefact reduction. We show that the use of a fine grid results in a more adequate suppression of artefacts than the smoothing of projections or using the Kaiser-Bessel image representation.

Original languageEnglish (US)
Pages (from-to)1877-1889
Number of pages13
JournalPhysics in Medicine and Biology
Volume51
Issue number7
DOIs
StatePublished - Apr 7 2006
Externally publishedYes

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Artifacts
artifacts
X-Rays
X rays
Bessel functions
projection
x rays
grids
smoothing
X Ray Computed Tomography
Computer-Assisted Image Processing
retarding
interference
simulation

ASJC Scopus subject areas

  • Biomedical Engineering
  • Physics and Astronomy (miscellaneous)
  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Comparison of methods for suppressing edge and aliasing artefacts in iterative x-ray CT reconstruction. / Zbijewski, Wojciech; Beekman, Freek J.

In: Physics in Medicine and Biology, Vol. 51, No. 7, 07.04.2006, p. 1877-1889.

Research output: Contribution to journalArticle

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