Reduction of artifacts due to multiple metallic objects in computed tomography

Levon Vogelsang, Yao Lu, Bo Yu, Andrzej Krol, Yuesheng Xu, Xiaofei Xu, David Feiglin, Edward Lipson

Research output: Chapter in Book/Entry/PoemConference contribution

18 Scopus citations


An X-ray computed tomography (CT) image including metallic objects suffers from annoying metal artifacts such as shades and streaks. In this paper, we propose a novel algorithm for reducing metal artifacts via a reprojectionreconstruction process. In the proposed algorithm, we first reconstruct a CT image from the original projection data. We then remove metallic object regions and replace them with the value of soft-tissue; apply total-variation-based smoothing to the image in order to reduce streak artifacts while preserving the shapes of non-metallic objects; and obtain the reprojection data of the smoothened image. Even though the reprojection data do not contain metallic objects, remaining shade artifacts (especially in the regions between metal objects) still affect the reprojection data. Those artifacts are found to be mainly concentrated in overlapping regions of metal-traces in the reprojection data. Hence, we horizontally interpolate the overlapping region with intensity values of its boundary pixels. We then replace whole metal trace regions in the original projection data with the processed reprojection data. The completed projection data are then used for the reconstruction of the final image. The proposed algorithm can reduce streak and shade artifacts while preserving the shape of non-metallic objects. It is proved that the proposed algorithm provides noticeably better performance in metal artifact reduction compared with the algorithms based on linear interpolation and the model image reprojection.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2009
Subtitle of host publicationPhysics of Medical Imaging
StatePublished - 2009
EventMedical Imaging 2009: Physics of Medical Imaging - Lake Buena Vista, FL, United States
Duration: Feb 9 2009Feb 12 2009

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherMedical Imaging 2009: Physics of Medical Imaging
Country/TerritoryUnited States
CityLake Buena Vista, FL


  • Computed tomography
  • Metal artifact reduction
  • Reprojection
  • Sinogram
  • Total-variation-based smoothing

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging


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