Evaluation of sinogram consistency conditions for identifying artifactual PET attenuation images


Journal Article

In PET/CT, PET attenuation maps are produced from the CT image resulting in localized defects due ambiguities in the conversion process. An example of a source of difficulty is CT contrast agent. The suitability of sinogram consistency conditions (SCCs) for objective functions (OFs) in algorithms for assessing the presence of artifacts is evaluated. Given a measured sinogram and two possible attenuation images the accuracy with which SCC-based OFs identify the artifact-free image is gauged. Digital phantom sets, each consisting of a true emission and attenuation component, were used. From each, 128 2D "measured" sinogram statistical variates at 7 noise levels representing sinogram counts from 103 to 107 were produced. Artifactual attenuation images were made by modifying the true attenuation phantoms. True and artifactual attenuation corrected sinograms (test pair) for each measured sinogram were produced. SCCs state that with consistent data, certain "forbidden" coefficients (FCs) from the Fourier transform over angle of the various radial moments of the corrected sinogram vanish. Schemes for combining FCs into an OF were investigated and classification accuracy was determined. A high-performing SCC-based OF produced an accuracy of 92% at the 107 count level for phantoms with a 2 cm2 artifact. Performance fell with increasing noise. At 105 counts accuracy was 53% (chance=50%). Better performance was obtained with larger artifacts. SCC objective functions may be useful in artifact correction, but are limited by low-count-level performance. © 2005 IEEE.

Full Text

Duke Authors

Cited Authors

  • Laymon, CM; Swadley, M; Bowsher, JE; Blodgett, T; Ziolko, SK

Published Date

  • December 1, 2005

Published In

Volume / Issue

  • 3 /

Start / End Page

  • 1611 - 1614

International Standard Serial Number (ISSN)

  • 1095-7863

Digital Object Identifier (DOI)

  • 10.1109/NSSMIC.2005.1596627

Citation Source

  • Scopus