Improved Detection of Foreign Bodies on Radiographs Using X-ray Dark-Field and Phase-Contrast Imaging

Hellbach, Katharina; Beller, Ebba; Schindler, Andreas; Schoeppe, Franziska; Hesse, Nina; Baumann, Anna; Schinner, Regina; Auweter, Sigrid; Hauke, Christian; Radicke, Marcus; Meinel, Felix G.

doi:10.1097/rli.0000000000000450

Cited by 10 publications

(5 citation statements)

References 21 publications

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“…In this study the imaging characteristics of microbubble ultrasound contrast media and microsphere particles, acquired with a preclinical dark-field and phase-contrast imaging scanner, are reported. The imaging setup was successfully used with idealized parameters for preclinical animal investigations published previously [39][40][41] . This study was challenging, as the bubbles float.…”

Section: Discussionmentioning

confidence: 99%

“…The prototype is part of a research project cluster and is not commercially available. This www.nature.com/scientificreports www.nature.com/scientificreports/ machine was successfully applied for animal and human sample investigations published previously [39][40][41] . In this preclinical study approval by the local ethical review board was waived, because the experimental setting was neither on human nor on animals.…”

Section: Methodsmentioning

confidence: 99%

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Imaging characteristics of intravascular spherical contrast agents for grating-based x-ray dark-field imaging – effects of concentrations, spherical sizes and applied voltage

Notohamiprodjo

Treitl

Hauke

et al. 2020

Sci Rep

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this study investigates the x-ray scattering characteristics of microsphere particles in x-ray-gratingbased interferometric imaging at different concentrations, bubble sizes and tube voltages (kV). Attenuation (ATI), dark-field (DFI) and phase-contrast (PCI) images were acquired. Signal-to-noise (SNR) and contrast-to-noise ratios with water (CNR w) and air as reference (CNR a) were determined. in all modalities, a linear relationship between SnR and microbubbles concentration, respectively, microsphere size was found. A significant gain of SNR was found when varying kV. SNR was significantly higher in DFI and PCI than ATI. The highest gain of SNR was shown at 60 kV for all media in ATI and DFI, at 80 kV for PCI. SNR for all media was significantly higher compared to air and was slightly lower compared to water. A linear relationship was found between CNR a , cnR w , concentration and size. With increasing concentration and decreasing size, cnR a and cnR w increased in DFI, but decreased in PCI. Best cnR a and cnR w was found at specific combination of kV and concentration/size. Highest average cnR a and cnR w was found for microspheres in ATI and PCI, for microbubbles in DFI. Microspheres are a promising contrast-media for grating-based-interferometry, if kV, microsphere size and concentration are appropriately combined. Contrast differences in conventional X-ray imaging rely on the varying degree of attenuation of x-rays penetrating different types of tissue. Contrast is highest in imaging materials with large differences in atomic number, material density, or both, such as bone or lung. However, in clinical radiography structures with only slight density differences, such as the tissue composition within inner organs, need to be examined as well, limiting the usefulness of x-ray attenuation imaging (ATI). Current research focuses on the phase change when the x-ray beam passes through the imaging object. Besides attenuation, alterations in phase change in different types of soft tissue provide additional contrast information. Here, image contrast is generated from interference of the x-ray wave front, caused by a phase shift of the x-ray wave while passing through the object. The phase of a wave front cannot be measured directly. Therefore, the imaging method requires a translation from phase shift to intensity differences. There are various approaches to retrieve phase information from x-ray imaging, including free-space propagation

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Imaging characteristics of intravascular spherical contrast agents for grating-based x-ray dark-field imaging – effects of concentrations, spherical sizes and applied voltage

Notohamiprodjo

Treitl

Hauke

et al. 2020

Sci Rep

Self Cite

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“…The transition to clinical routine is currently taking place with the first patient scanner capable to provide dark-field radiography images of a living human thorax 12 . Alternative applications range from foreign body detection 13 , 14 to mammography 15 , 16 . Moreover, the X-ray dark-field signal induced by sub-pixel microstructures is of interest for material science.…”

Section: Introductionmentioning

confidence: 99%

Spectral X-ray dark-field signal characterization from dual-energy projection phase-stepping data with a Talbot-Lau interferometer

Taphorn

Kaster

Sellerer

et al. 2023

Sci Rep

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Material-selective analysis of spectral X-ray imaging data requires prior knowledge of the energy dependence of the observed signal. Contrary to conventional X-ray imaging, where the material-specific attenuation coefficient is usually precisely known, the linear diffusion coefficient of the X-ray dark-field contrast does not only depend on the material and its microstructure, but also on the setup geometry and is difficult to access. Here, we present an optimization approach to retrieve the energy dependence of the X-ray dark-field signal quantitatively on the example of closed-cell foams from projection data without the need for additional hardware to a standard grating-based X-ray dark-field imaging setup. A model for the visibility is used to determine the linear diffusion coefficient with a least-squares optimization. The comparison of the results to spectrometer measurements of the linear diffusion coefficient suggests the proposed method to provide a good estimate for the energydependent dark-field signal.

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“…The refraction signal features improved soft-tissue contrast, while the dark-field signal enables the detection of unresolved microstructures below the spatial resolution of x-ray grating interferometer. [6] Over the past decades, x-ray grating interferometry has shown significant potential in diverse applications including, but not limited to: mammography, [19,20] cardiovascular imaging, [21] materials science, [22,23] non-destructive testing, [24,25] detection of foreign bodies, [26] and chest imaging for early detection of pulmonary emphysema. [27][28][29] In x-ray grating interferometry, the phase-stepping technique is commonly used for data acquisition.…”

Section: Introductionmentioning

confidence: 99%

Investigations of moiré artifacts induced by flux fluctuations in x-ray dark-field imaging

Wang

Zi-Han²,

Yao³

et al. 2023

Chinese Phys. B

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X-ray dark-field imaging using a grating interferometer has shown potential benefits for a variety of applications in recent years. X-ray dark-field image is commonly retrieved by using discrete Fourier transform from the acquired phase-stepping data. The retrieval process assumes a constant phase step size and a constant flux for each stepped grating position. However, stepping errors and flux fluctuations inevitably occur due to external vibrations and/or thermal drift during data acquisition. Previous studies have shown that those influences introduce errors in the acquired phase-stepping data, which cause obvious moiré artifacts in the retrieved refraction image. This work investigates moiré artifacts in X-ray dark-field imaging as a result of flux fluctuations. For the retrieved mean intensity, amplitude, visibility and dark-field images, the dependence of moiré artifacts on flux fluctuation factors is theoretically derived respectively by using a first-order Taylor series expansion. Results of synchrotron radiation experiments verify the validity of derived analytical formulas. The spatial frequency characteristics of moiré artifacts are analyzed and compared to those induced by phase-stepping errors. It’s illustrated that moiré artifacts can be estimated by a weighted mean of flux fluctuation factors, with the weighting factors dependent on the moiré phase and different greatly for each retrieved image. Furthermore, moiré artifacts can even be affected by object’s features not displayed in the particular contrast. These results can be used to interpret image correctly, identify sources of moiré artifacts, and develop dedicated algorithms to remove moiré artefacts in the retrieved multi-contrast images.

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Improved Detection of Foreign Bodies on Radiographs Using X-ray Dark-Field and Phase-Contrast Imaging

Abstract: Adding dark-field images substantially improves the detection of wooden foreign bodies compared with the analysis of conventional (transmission) radiographs alone. Detection of glass foreign bodies was moderately improved when adding phase-contrast images.

Cited by 10 publications

References 21 publications

Imaging characteristics of intravascular spherical contrast agents for grating-based x-ray dark-field imaging – effects of concentrations, spherical sizes and applied voltage

Imaging characteristics of intravascular spherical contrast agents for grating-based x-ray dark-field imaging – effects of concentrations, spherical sizes and applied voltage

Spectral X-ray dark-field signal characterization from dual-energy projection phase-stepping data with a Talbot-Lau interferometer

Investigations of moiré artifacts induced by flux fluctuations in x-ray dark-field imaging

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