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

2020 ◽  
Vol 49 (6) ◽  
pp. 642-650
Author(s):  
Aileen Eyou ◽  
Benedicta D Arhatari ◽  
Chanh Quoc Tran
2016 ◽  
Vol 23 (5) ◽  
pp. 1137-1142 ◽  
Author(s):  
Elena Eggl ◽  
Martin Dierolf ◽  
Klaus Achterhold ◽  
Christoph Jud ◽  
Benedikt Günther ◽  
...  

While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented.


Author(s):  
H. C. Corcoran ◽  
S. B. Brown ◽  
S. Robson ◽  
R. D. Speller ◽  
M. B. McCarthy

X-ray computed tomography (XCT) is a rising technology within many industries and sectors with a demand for dimensional metrology, defect, void analysis and reverse engineering. There are many variables that can affect the dimensional metrology of objects imaged using XCT, this paper focusses on the effects of beam hardening due to the orientation of the workpiece, in this case a holeplate, and the volume of material the X-rays travel through. Measurements discussed include unidirectional and bidirectional dimensions, radii of cylinders, fit point deviations of the fitted shapes and cylindricity. Results indicate that accuracy and precision of these dimensional measurements are affected in varying amounts, both by the amount of material the X-rays have travelled through and the orientation of the object.


Author(s):  
Jing Zhang ◽  
Yongliang Tian ◽  
Qi Liu ◽  
Ling He ◽  
Kai Liu

1990 ◽  
Vol 17 (4) ◽  
pp. 701-704 ◽  
Author(s):  
A. M. Kalend ◽  
Andrew Wu ◽  
V. Yoder ◽  
A. Maitz

Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1387 ◽  
Author(s):  
M. A. Hamza ◽  
S. H. Anderson ◽  
L. A. G. Aylmore

Application of computer-assisted tomography to the attenuation of X-rays has been used to compare the drawdowns in soil water content associated with radish roots at starting soil water contents (θv) of 0.3 cm3/cm3 and 0.1 cm3/cm3, respectively. Decreasing soil water content results in an increase in the appearance of ‘beam hardening’. Decreasing soil water content from 0.3 to 0.1 cm3/cm3 caused the transpiration rate to decrease by 6–10 times. This was presumably due to a reduction in the water potential gradient across the root membrane. The transpiration rate decreased less rapidly than did the water content at the soil–root interface, suggesting some osmotic adjustment by the leaves. This osmotic adjustment would allow the plant to maintain transpiration rate even at relatively low soil water content. The drawdown distances associated with roots growing at the lower soil water content were 8 times smaller than those at the high soil water content and the value of θv at the soil–root interface at the end of the transpiration period was 2.5 times lower. The radish roots exhibited a temporary slight decrease in diameter after the transpiration commenced followed by a significant temporary increase. However, root diameter stabilised around its original value when the plant attained an almost steady water uptake rate. Despite the complexity arising from ‘beam hardening’, CAT scanning can provide valuable information on processes at the root–soil interface.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Daniela D'Ambrosio ◽  
Federico Zagni ◽  
Antonello E. Spinelli ◽  
Mario Marengo

In order to extract quantitative parameters from PET images, several physical effects such as photon attenuation, scatter, and partial volume must be taken into account. The main objectives of this work were the evaluation of photon attenuation in small animals and the implementation of two attenuation correction methods based on X-rays CT and segmentation of emission images. The accuracy of the first method with respect to the beam hardening effect was investigated by using Monte Carlo simulations. Mouse- and rat-sized phantoms were acquired in order to evaluate attenuation correction in terms of counts increment and recovery of uniform activity concentration. Both methods were applied to mice and rat images acquired with several radiotracers such asF18-FDG,11C-acetate,68Ga-chloride, andF18-NaF. The accuracy of the proposed methods was evaluated in heart and tumour tissues usingF18-FDG images and in liver, kidney, and spinal column tissues usingC11-acetate,Ga68-chloride, andF18-NaF images, respectively.In vivoresults from animal studies show that, except for bone scans, differences between the proposed methods were about 10% in rats and 3% in mice. In conclusion, both methods provide equivalent results; however, the segmentation-based approach has several advantages being less time consuming and simple to implement.


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