Phase-space formulation for phase-contrast x-ray imaging

Academic Article

Abstract

  • Phase-space formulation based on the Wigner distribution has been presented for analyzing phase-contrast image formation. Based on the statistical nature and affine canonical covariance of Wigner distributions in the phase space, we show that the partial coherence effects of incident x-ray wave field on image intensity are simply accounted for by a multiplication factor, which is the reduced complex degree of coherence of the incident x-ray wave field. We show especially that with the undulator sources one cannot obtain the phase-contrast intensity by summing over the contributions from all electron positions, since the van Cittert-Zernike theorem fails in general for undulators. We derive a comprehensive formula that quantifies the effects of partial spatial coherence, polychromatic spectrum, body attenuation, imaging-detector resolution, and radiation dose on phase-contrast visibility in clinical imaging. The results of our computer modeling and simulations show how the formula can provide design guidelines and optimal parameters for clinical x-ray phase-contrast imaging systems. © 2005 Optical Society of America.
  • Authors

    Published In

  • Applied Optics  Journal
  • Digital Object Identifier (doi)

    Author List

  • Wu X; Liu H
  • Start Page

  • 5847
  • End Page

  • 5854
  • Volume

  • 44
  • Issue

  • 28