A simple motion tracking backprojection for a class of affine transformation

Katsuyuki Taguchi, Hiroyuki Kudo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations


Image reconstruction of dynamically deforming objects from projections and known time-dependent motion field is of interest for x-ray computed tomography. Recently, three analytical exact methods have been developed based on DFBP or DBPF algorithms which compensates for time-dependent standard affine or relaxed affine transformation [1-3]. In contrast, an empirical algorithm has been proposed by Schafer, et ah, which merely "trace" the motion of each voxel during the backprojection process [4, 5]. The method is known to be an approximation; however, it has not been discussed how good or bad the level of approximation is. In this paper, we present that a slightly modified Schafer's method (FBPx) is exact if the motion of the object can be described by a class of time-dependent affine transformation-isotropic scaling (contraction and expansion), rotation, and translation. We show mathematically and experimentally that Schafer's method is a good approximation.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2008 - Physics of Medical Imaging
StatePublished - 2008
EventMedical Imaging 2008 - Physics of Medical Imaging - San Diego, CA, United States
Duration: Feb 18 2008Feb 21 2008

Publication series

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


OtherMedical Imaging 2008 - Physics of Medical Imaging
Country/TerritoryUnited States
CitySan Diego, CA


  • Computed tomography
  • Deforming object
  • Motion compensation

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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