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X-ray Phase-contrast imaging

Martin Bech

Universitetslektor

X-ray Phase-contrast imaging

Contrast-to-noise ratio optimization for a prototype phase-contrast computed tomography scanner.

Författare

  • Mark Müller
  • Andre Yaroshenko
  • Astrid Velroyen
  • Martin Bech
  • Arne Tapfer
  • Bart Pauwels
  • Peter Bruyndonckx
  • Alexander Sasov
  • Franz Pfeiffer

Summary, in English

In the field of biomedical X-ray imaging, novel techniques, such as phase-contrast and dark-field imaging, have the potential to enhance the contrast and provide complementary structural information about a specimen. In this paper, a first prototype of a preclinical X-ray phase-contrast CT scanner based on a Talbot-Lau interferometer is characterized. We present a study of the contrast-to-noise ratios for attenuation and phase-contrast images acquired with the prototype scanner. The shown results are based on a series of projection images and tomographic data sets of a plastic phantom in phase and attenuation-contrast recorded with varying acquisition settings. Subsequently, the signal and noise distribution of different regions in the phantom were determined. We present a novel method for estimation of contrast-to-noise ratios for projection images based on the cylindrical geometry of the phantom. Analytical functions, representing the expected signal in phase and attenuation-contrast for a circular object, are fitted to individual line profiles of the projection data. The free parameter of the fit function is used to estimate the contrast and the goodness of the fit is determined to assess the noise in the respective signal. The results depict the dependence of the contrast-to-noise ratios on the applied source voltages, the number of steps of the phase stepping routine, and the exposure times for an individual step. Moreover, the influence of the number of projection angles on the image quality of CT slices is investigated. Finally, the implications for future imaging purposes with the scanner are discussed.

Avdelning/ar

  • Medicinsk strålningsfysik, Lund

Publiceringsår

2015

Språk

Engelska

Publikation/Tidskrift/Serie

Review of Scientific Instruments

Volym

86

Issue

12

Dokumenttyp

Artikel i tidskrift

Förlag

American Institute of Physics (AIP)

Ämne

  • Radiology, Nuclear Medicine and Medical Imaging

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 1089-7623