Dark-field tomography of an attenuating object using intrinsic x-ray speckle tracking.

Type of content
Journal Article
Thesis discipline
Degree name
Publisher
SPIE-Intl Soc Optical Eng
Journal Title
Journal ISSN
Volume Title
Language
eng
Date
2022
Authors
Alloo SJ
Paganin DM
Morgan KS
Kitchen MJ
Stevenson AW
Mayo SC
Li HT
Maksimenko A
Bowden JC
Kennedy , Ben
Abstract

Purpose: We investigate how an intrinsic speckle tracking approach to speckle-based x-ray imaging is used to extract an object's effective dark-field (DF) signal, which is capable of providing object information in three dimensions. Approach: The effective DF signal was extracted using a Fokker-Planck type formalism, which models the deformations of illuminating reference beam speckles due to both coherent and diffusive scatter from the sample. Here, we assumed that (a) small-angle scattering fans at the exit surface of the sample are rotationally symmetric and (b) the object has both attenuating and refractive properties. The associated inverse problem of extracting the effective DF signal was numerically stabilized using a "weighted determinants" approach. Results: Effective DF projection images, as well as the DF tomographic reconstructions of the wood sample, are presented. DF tomography was performed using a filtered back projection reconstruction algorithm. The DF tomographic reconstructions of the wood sample provided complementary, and otherwise inaccessible, information to augment the phase contrast reconstructions, which were also computed. Conclusions: An intrinsic speckle tracking approach to speckle-based imaging can tomographically reconstruct an object's DF signal at a low sample exposure and with a simple experimental setup. The obtained DF reconstructions have an image quality comparable to alternative x-ray DF techniques.

Description
Citation
Alloo SJ, Paganin DM, Morgan KS, Kitchen MJ, Stevenson AW, Mayo SC, Li HT, Kennedy BM, Maksimenko A, Bowden JC, Pavlov KM (2022). Dark-field tomography of an attenuating object using intrinsic x-ray speckle tracking.. Journal of medical imaging (Bellingham, Wash.). 9(3). 031502-.
Keywords
dark-field computed tomography, intrinsic speckle tracking, speckle x-ray imaging
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Fields of Research::34 - Chemical sciences::3406 - Physical chemistry::340605 - Molecular imaging (incl. electron microscopy and neutron diffraction)
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All rights reserved unless otherwise stated