Soft-tissue differentiation and bone densitometry via energy-discriminating X-ray microCT

Yokhana, Viona S. K.; Arhatari, Benedicta D.; Gureyev, T. E.; Abbey, Brian

doi:10.1364/oe.25.029328

Cited by 15 publications

(9 citation statements)

References 30 publications

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“…In addition, while methods like K-edge subtraction are no longer applicable, measurement of relative attenuation changes over the energy range enables segmentation of poorly contrasting materials, which otherwise cannot be differentiated in conventional X-ray CT 16 . Previous work on bone densitometry and soft tissue segmentation has been shown to be possible with few channel spectroscopic imaging, without the need for contrast agents 32 .…”

Section: Discussionmentioning

confidence: 99%

Enhanced hyperspectral tomography for bioimaging by spatiospectral reconstruction

Warr,

Ametova,

Cernik

et al. 2021

Preprint

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Here we apply hyperspectral bright field imaging to collect computed tomographic images with excellent energy resolution (800 eV), applying it for the first time to map the distribution of stain in a fixed biological sample through its characteristic K-edge. Conventionally, because the photons detected at each pixel are distributed across as many as 200 energy channels, energy-selective images are characterised by low count-rates and poor signal-to-noise ratio. This means high X-ray exposures, long scan times and high doses are required to image unique spectral markers. Here, we achieve high quality energy-dispersive tomograms from low dose, noisy datasets using a dedicated iterative reconstruction algorithm. This exploits the spatial smoothness and inter-channel structural correlation in the spectral domain using two carefully chosen regularisation terms. For a multi-phase phantom, a reduction in scan time of 36 times is demonstrated. Spectral analysis methods including K-edge subtraction and absorption step-size fitting are evaluated for an ex vivo, single (iodine)-stained biological sample, where low chemical concentration and inhomogeneous distribution can affect soft tissue segmentation and visualisation. The reconstruction algorithms are available through the open-source Core Imaging Library. Taken together, these tools offer new capabilities for visualisation and elemental mapping, with promising applications for multiply-stained biological specimens.

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Section: Discussionmentioning

confidence: 99%

Enhanced hyperspectral tomography for bioimaging by spatiospectral reconstruction

Warr,

Ametova,

Cernik

et al. 2021

Preprint

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“…Recent development in technology has made it possible for spatially resolved detectors, such as Pilatus [ 21 ] or Pixirad, [ 44,45 ] to count only incoming photons with energies higher than a threshold level set by users. Applications of our technique to imaging work using these detectors promise great potentials in quantitative elemental contrast imaging and will also be investigated.…”

Section: Discussionmentioning

confidence: 99%

Complete elimination of the beam hardening effect in quantitative absorption tomography using polychromatic x‐rays with single‐component specimens

2020

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/Award Number: Internal Absorption tomography has been a unique technique for 3D imaging in many scientific research and applications. However, the use of polychromatic x-ray sources for quantitative tomography has been limited due to the well-known beam hardening effect. In this article, we will describe the theoretical details of a new technique for quantitative tomography using polychromatic x-rays. The technique incorporates the full spectral information of the incident beam into the tomographic reconstruction process. Consequently, beam-hardening effects are eliminated and the result is quantitative. We will also demonstrate the technique experimentally using a single-component specimen. This technique promises great opportunities for laboratory-based x-ray sources to be used in quantitative applications.

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“…where I 0 is the incident intensity. For low-density materials, such as soft tissue, the X-ray attenuation generates only relatively low contrast [22]. By comparison, in the hard X-ray regime, the phase shift is typically three orders of magnitude larger than the corresponding absorption.…”

Section: Introductionmentioning

confidence: 99%

X-ray Phase-Contrast Computed Tomography for Soft Tissue Imaging at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron

et al. 2021

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The Imaging and Medical Beamline (IMBL) is a superconducting multipole wiggler-based beamline at the 3 GeV Australian Synchrotron operated by the Australian Nuclear Science and Technology Organisation (ANSTO). The beamline delivers hard X-rays in the 25–120 keV energy range and offers the potential for a range of biomedical X-ray applications, including radiotherapy and medical imaging experiments. One of the imaging modalities available at IMBL is propagation-based X-ray phase-contrast computed tomography (PCT). PCT produces superior results when imaging low-density materials such as soft tissue (e.g., breast mastectomies) and has the potential to be developed into a valuable medical imaging tool. We anticipate that PCT will be utilized for medical breast imaging in the near future with the advantage that it could provide better contrast than conventional X-ray absorption imaging. The unique properties of synchrotron X-ray sources such as high coherence, energy tunability, and high brightness are particularly well-suited for generating PCT data using very short exposure times on the order of less than 1 min. The coherence of synchrotron radiation allows for phase-contrast imaging with superior sensitivity to small differences in soft-tissue density. Here we also compare the results of PCT using two different detectors, as these unique source characteristics need to be complemented with a highly efficient detector. Moreover, the application of phase retrieval for PCT image reconstruction enables the use of noisier images, potentially significantly reducing the total dose received by patients during acquisition. This work is part of ongoing research into innovative tomographic methods aimed at the introduction of 3D X-ray medical imaging at the IMBL to improve the detection and diagnosis of breast cancer. Major progress in this area at the IMBL includes the characterization of a large number of mastectomy samples, both normal and cancerous, which have been scanned at clinically acceptable radiation dose levels and evaluated by expert radiologists with respect to both image quality and cancer diagnosis.

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Soft-tissue differentiation and bone densitometry via energy-discriminating X-ray microCT

Cited by 15 publications

References 30 publications

Enhanced hyperspectral tomography for bioimaging by spatiospectral reconstruction

Enhanced hyperspectral tomography for bioimaging by spatiospectral reconstruction

Complete elimination of the beam hardening effect in quantitative absorption tomography using polychromatic x‐rays with single‐component specimens

X-ray Phase-Contrast Computed Tomography for Soft Tissue Imaging at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron

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