A beam hardening and dispersion correction for x-ray dark-field radiography

2016 ◽  
Vol 43 (6Part1) ◽  
pp. 2774-2779 ◽  
Author(s):  
Georg Pelzer ◽  
Gisela Anton ◽  
Florian Horn ◽  
Jens Rieger ◽  
André Ritter ◽  
...  
Keyword(s):  
Dark Field ◽  
Dispersion Correction ◽  
Beam Hardening ◽  
X Ray

scholarly journals Comparison of Thermal Neutron and Hard X-ray Dark-Field Tomography

2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Alex Gustschin ◽  
Tobias Neuwirth ◽  
Alexander Backs ◽  
Manuel Viermetz ◽  
Nikolai Gustschin ◽  
...  
Keyword(s):  
Neutron Radiation ◽  
Dark Field ◽  
Silica Matrix ◽  
Beam Hardening ◽  
X Ray ◽  
Beneficial Effects ◽  
Potential Applications ◽  
Grating Interferometer ◽  
Ct Slices ◽  
Tomography Scan

High visibility (0.56) neutron-based multi-modal imaging with a Talbot–Lau interferometer at a wavelength of 1.6 Å is reported. A tomography scan of a strongly absorbing quartz geode sample was performed with both the neutron and an X-ray grating interferometer (70 kVp) for a quantitative comparison. Small scattering structures embedded in the absorbing silica matrix were well resolved in neutron dark-field CT slices with a spatial resolution of about 300 μm. Beneficial effects, such as monochromaticity and stronger penetration power of the used neutron radiation, helped to avoid the beam hardening-related artificial dark-field signal which was present in the X-ray data. Both dark-field modalities show mostly the same structures; however, some scattering features appear only in the neutron domain. Potential applications of combined X-ray and neutron multi-modal CT enabling one to probe both the nuclear and the electron density-related structural properties are discussed. strongly absorbing samples are now accessible for the dark-field modality by the use of thermal neutrons.

scholarly journals Whole-body x-ray dark-field radiography of a human cadaver

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Jana Andrejewski ◽  
Fabio De Marco ◽  
Konstantin Willer ◽  
Wolfgang Noichl ◽  
Alex Gustschin ◽  
...  
Keyword(s):  
Effective Dose ◽  
Human Body ◽  
Small Angle ◽  
Dark Field ◽  
Whole Body ◽  
High Signal ◽  
Human Cadaver ◽  
Contrast Imaging ◽  
Beam Hardening ◽  
X Ray

Abstract Background Grating-based x-ray dark-field and phase-contrast imaging allow extracting information about refraction and small-angle scatter, beyond conventional attenuation. A step towards clinical translation has recently been achieved, allowing further investigation on humans. Methods After the ethics committee approval, we scanned the full body of a human cadaver in anterior-posterior orientation. Six measurements were stitched together to form the whole-body image. All radiographs were taken at a three-grating large-object x-ray dark-field scanner, each lasting about 40 s. Signal intensities of different anatomical regions were assessed. The magnitude of visibility reduction caused by beam hardening instead of small-angle scatter was analysed using different phantom materials. Maximal effective dose was 0.3 mSv for the abdomen. Results Combined attenuation and dark-field radiography are technically possible throughout a whole human body. High signal levels were found in several bony structures, foreign materials, and the lung. Signal levels were 0.25 ± 0.13 (mean ± standard deviation) for the lungs, 0.08 ± 0.06 for the bones, 0.023 ± 0.019 for soft tissue, and 0.30 ± 0.02 for an antibiotic bead chain. We found that phantom materials, which do not produce small-angle scatter, can generate a strong visibility reduction signal. Conclusion We acquired a whole-body x-ray dark-field radiograph of a human body in few minutes with an effective dose in a clinical acceptable range. Our findings suggest that the observed visibility reduction in the bone and metal is dominated by beam hardening and that the true dark-field signal in the lung is therefore much higher than that of the bone.

scholarly journals Modeling of beam hardening effects in a dual-phase X-ray grating interferometer for quantitative dark-field imaging

2020 ◽  
Vol 28 (13) ◽  
pp. 19187 ◽  
Author(s):  
Amogha Pandeshwar ◽  
Matias Kagias ◽  
Zhentian Wang ◽  
Marco Stampanoni
Keyword(s):  
Dark Field ◽  
Dual Phase ◽  
Beam Hardening ◽  
X Ray ◽  
Dark Field Imaging ◽  
Grating Interferometer ◽  
Field Imaging

Empirical Beam Hardening and Ring Artifact Correction for X‐Ray Grating Interferometry (EBHC‐GI)

2020 ◽  
Author(s):  
Brandon J. Nelson ◽  
Shuai Leng ◽  
Elisabeth R. Shanblatt ◽  
Cynthia H. McCollough ◽  
Thomas Koenig
Keyword(s):  
Beam Hardening ◽  
Artifact Correction ◽  
X Ray ◽  
Ring Artifact

scholarly journals Correlation of image quality parameters with tube voltage in X-ray dark-field chest radiography: a phantom study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreas P. Sauter ◽  
Jana Andrejewski ◽  
Manuela Frank ◽  
Konstantin Willer ◽  
Julia Herzen ◽  
...  
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Signal Strength ◽  
Dark Field ◽  
Tube Voltage ◽  
X Ray ◽  
Dose Area Product ◽  
Dark Field Imaging ◽  
Field Imaging

AbstractGrating-based X-ray dark-field imaging is a novel imaging modality with enormous technical progress during the last years. It enables the detection of microstructure impairment as in the healthy lung a strong dark-field signal is present due to the high number of air-tissue interfaces. Using the experience from setups for animal imaging, first studies with a human cadaver could be performed recently. Subsequently, the first dark-field scanner for in-vivo chest imaging of humans was developed. In the current study, the optimal tube voltage for dark-field radiography of the thorax in this setup was examined using an anthropomorphic chest phantom. Tube voltages of 50–125 kVp were used while maintaining a constant dose-area-product. The resulting dark-field and attenuation radiographs were evaluated in a reader study as well as objectively in terms of contrast-to-noise ratio and signal strength. We found that the optimum tube voltage for dark-field imaging is 70 kVp as here the most favorable combination of image quality, signal strength, and sharpness is present. At this voltage, a high image quality was perceived in the reader study also for attenuation radiographs, which should be sufficient for routine imaging. The results of this study are fundamental for upcoming patient studies with living humans.

Dark-Field X-Ray Microscopy of Immunogold-Labeled Cells

1996 ◽  
Vol 2 (2) ◽  
pp. 53-62 ◽  
Author(s):  
Henry N. Chapman ◽  
Jenny Fu ◽  
Chris Jacobsen ◽  
Shawn Williams
Keyword(s):  
Colloidal Gold ◽  
Dark Field Image ◽  
Dark Field ◽  
X Rays ◽  
X Ray ◽  
Scanning Transmission ◽  
A Cell ◽  
Specific Antigens ◽  
Genetic Sequences ◽  
Novel Method

The methods of immunolabeling make visible the presence of specific antigens, proteins, genetic sequences, or functions of a cell. In this paper we present examples of imaging immunolabels in a scanning transmission x-ray microscope using the novel method of dark-field contrast. Colloidal gold, or silver-enhanced colloidal gold, is used as a label, which strongly scatters x-rays. This leads to a high-contrast dark-field image of the label and reduced radiation dose to the specimen. The x-ray images are compared with electron micrographs of the same labeled, unsectioned, whole cell. It is verified that the dark-field x-ray signal is primarily due to the label and the bright-field x-ray signal, showing absorption due to carbon, is largely unaffected by the label. The label can be well visualized even when it is embedded in or laying behind dense material, such as the cell nucleus. The resolution of the images is measured to be 60 nm, without the need for computer processing. This figure includes the x-ray microscope resolution and the accuracy of the label positioning. The technique should be particularly useful for the study of relatively thick (up to 10 μm), wet, or frozen hydrated specimens.

Mapping misoriented fibers using X-ray dark field tomography

2014 ◽  
Vol 115 (3) ◽  
pp. 741-745 ◽  
Author(s):  
Torsten Lauridsen ◽  
Erik M. Lauridsen ◽  
Robert Feidenhans’l
Keyword(s):  
Dark Field ◽  
X Ray

Incorporating dark-field information in mesh-based x-ray phase imaging

2021 ◽  
Author(s):  
Uttam Pyakurel ◽  
Desiree D'Moore ◽  
Pikting Cheung ◽  
Bushra Kanwal ◽  
Xiaoyun Zhang ◽  
...  
Keyword(s):  
Dark Field ◽  
Phase Imaging ◽  
X Ray ◽  
Field Information

scholarly journals Erratum: “Signal-to-noise ratio in x-ray dark-field imaging using a grating interferometer” [J. Appl. Phys. 110, 053105 (2011)]

2011 ◽  
Vol 110 (10) ◽  
pp. 109902 ◽  
Author(s):  
Michael Chabior ◽  
Tilman Donath ◽  
Christian David ◽  
Manfred Schuster ◽  
Christian Schroer ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Dark Field ◽  
Signal To Noise ◽  
X Ray ◽  
Dark Field Imaging ◽  
Grating Interferometer ◽  
Noise Ratio ◽  
Field Imaging
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