Comparison of medical and industrial X-ray computed tomography for non-destructive testing

Plessis, Anton du; Roux, Stéphan; Guelpa, Anina

doi:10.1016/j.csndt.2016.07.001

Cited by 90 publications

(58 citation statements)

References 12 publications

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“…Industrial X‐ray imaging offers a nondestructive testing method that is increasingly applied . While medical systems are usually optimized for low radiation doses, short scan times and best contrasts for their specific application, industrial X‐ray sources do not have these constraints and can be optimized for optimal penetration power and resolution even for dense objects like metal parts .…”

Section: Methodsmentioning

confidence: 99%

Investigation of the Axial Gap Clearance in a Hydrodynamic‐Passive Magnetically Levitated Rotary Blood Pump Using X‐Ray Radiography

et al. 2018

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The HeartWare HVAD is a radial rotary blood pump with a combination of passive magnetic and hydrodynamic bearings to levitate the impeller. The axial gap size between impeller and housing in this bearing and its sensitivity to speed, flow, and pressure difference is difficult to assess. Shear stresses are exceptionally high in this tiny gap making it important for blood damage and related adverse events. Therefore, the aim of this study was to measure the axial gap clearance in the HVAD at different operating conditions employing radiography. To quantify the gap size in the HVAD, the pump was positioned 30 mm in front of the X-ray source employing a microfocus X-ray tube with an acceleration voltage up to 300 kV. Beams were detected on a flat panel detector (Perkin Elmer XRD 1611-CP3). The pump was connected to a tubing circuit with a throttle to adjust flow (0, 5, 10 L/min) and a water glycerol mixture to set the desired viscosity (1, 4, 8 mPas). Rotational speed was varied between 1800 and 3600 rpm. In this study, for clinically relevant conditions at 5 L/min and 2700 rpm, the axial gap was 22 µm. The gap size increased with rotational speeds dependent on the viscosity (2.8, 6.9, and 9.4 µm/1000 rpm for 1, 4, and 8 mPas, respectively), but was independent from the volume flow and the pressure head at constant speeds. In summary, using X-ray radiographic imaging small gaps in a rotary blood pump during operation can be measured in a nondestructive contact-free way. The axial hydrodynamic bearing gap in the HVAD pump was determined to be in the range of about three times the diameter of a red blood cell. Its dependence on operating volume flow and generated pressure head across the pump is not pronounced.

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Section: Methodsmentioning

confidence: 99%

Investigation of the Axial Gap Clearance in a Hydrodynamic‐Passive Magnetically Levitated Rotary Blood Pump Using X‐Ray Radiography

et al. 2018

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“…Micro-computed tomography or X-ray microtomography (CT) provides a powerful tool for visualization of internal and 3D structures of biological specimens [1], [2], biomaterials [3], [4], and various industrial applications [5], [6]. Conventional X-ray microtomography relies on the attenuation of the X-rays in the sample, which is used to generate an attenuation map of the sample.…”

Section: Introductionmentioning

confidence: 99%

Augmenting Soft Tissue Contrast Using Edge-Enhancing Phase-Imaging Techniques in X-Ray Microtomography

Reunamo

Hannula

Hyttinen

2019

2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

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Conventional X-ray imaging is based on the attenuation of X-rays and the technique provides sufficient contrast when the difference between attenuation coefficients of neighboring structures is sufficient. A promising imaging possibility on a µCT is the use of phase information of an Xray beam to generate an image of the sample. This is known as phase-contrast imaging. Propagation-based phase imaging sets the least amount of requirements on the imaging setuplateral coherence for the X-ray source and a movable detector and source. The Zeiss Xradia MicroXCT-400 at our laboratory provides this possibility. Therefore, the phase-contrast imaging protocol, which provides an edge-enhancement effect, on the µCT device was optimized using thin polylactic acid fibers in order to enhance the visibility of low density samples. The optimization consisted of source and detector distance variation measurements. To demonstrate the contrast enhancement results, the optimization was applied to two types of collagen samples embedded in air, ethanol, and water. The results showed enhanced contrast for the edge-enhanced phase-contrast images compared to absorption images. Most importantly, the results indicated that the source does not need to placed at the negative limit to obtain useful phase information. Additionally, the visibility increases with increasing sample-to-detector distance. Finally, significantly enhanced contrast was obtained for the collagen sample embedded in water using phase-imaging techniques. The technique is limited due to the focal spot size and voltage of the X-ray source. The phase-imaging technique has the possibility to enhance contrast of low density samples and to reveal structures that cannot be seen using other imaging techniques.

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“…X-ray computed tomography (CT) is employed in a wide range of fields including clinical imaging, biomedical research, materials sciences, industrial non-destructive testing and cultural heritage [1][2][3][4][5]. In some cases, specialized and highly optimized CT systems can deliver accurate and reproducible three-dimensional reconstructions.…”

Section: Introductionmentioning

confidence: 99%

Registration-based multi-orientation tomography

2018

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We propose a combination of an experimental approach and a reconstruction technique that leads to reduction of artefacts in X-ray computer tomography of strongly attenuating objects. Through fully automatic data alignment, data generated in multiple experiments with varying object orientations are combined. Simulations and experiments show that the solutions computed using algebraic methods based on multiple acquisitions can achieve a dramatic improvement in the reconstruction quality, even when each acquisition generates a reduced number of projections. The approach does not require any advanced setup components making it ideal for laboratorybased X-ray tomography.

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Comparison of medical and industrial X-ray computed tomography for non-destructive testing

Cited by 90 publications

References 12 publications

Investigation of the Axial Gap Clearance in a Hydrodynamic‐Passive Magnetically Levitated Rotary Blood Pump Using X‐Ray Radiography

Investigation of the Axial Gap Clearance in a Hydrodynamic‐Passive Magnetically Levitated Rotary Blood Pump Using X‐Ray Radiography

Augmenting Soft Tissue Contrast Using Edge-Enhancing Phase-Imaging Techniques in X-Ray Microtomography

Registration-based multi-orientation tomography

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