scholarly journals Multiscale X-ray imaging using ptychography

2018 ◽  
Vol 25 (4) ◽  
pp. 1214-1221 ◽  
Author(s):  
Simone Sala ◽  
Venkata S. C. Kuppili ◽  
Stefanos Chalkidis ◽  
Darren J. Batey ◽  
Xiaowen Shi ◽  
...  
Keyword(s):  
Generation X ◽  
Imaging Techniques ◽  
X Rays ◽  
Widespread Application ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Imaging Mode ◽  
Resolution Imaging ◽  
Complementary Techniques

The success of ptychography and other imaging experiments at third-generation X-ray sources is apparent from their increasingly widespread application and the improving quality of the images they produce both for resolution and contrast and in terms of relaxation of experimental constraints. The wider availability of highly coherent X-rays stimulates the development of several complementary techniques which have seen limited mutual integration in recent years. This paper presents a framework in which some of the established imaging techniques – with particular regard for ptychography – are flexibly applied to tackle the variable requirements occurring at typical synchrotron experiments. In such a framework one can obtain low-resolution images of whole samples and smoothly zoom in on specific regions of interest as they are revealed by switching to a higher-resolution imaging mode. The techniques involved range from full-field microscopy, to reach the widest fields of view (>mm), to ptychography, to achieve the highest resolution (<100 nm), and have been implemented at the I13 Coherence Branchline at Diamond Light Source.

scholarly journals Truncated Inception Net: COVID-19 Outbreak Screening using Chest X-rays

2020 ◽  
Author(s):  
Dipayan Das ◽  
KC Santosh ◽  
Umapada Pal
Keyword(s):  
Neural Network ◽  
World Wide ◽  
Imaging Techniques ◽  
Imaging Systems ◽  
Ct Scans ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Proposed Model ◽  
Different Types

Abstract Since December 2019, the Coronavirus Disease (COVID-19) pandemic has caused world-wide turmoil in less than a couple of months, and the infection, caused by SARS-CoV-2, is spreading at an unprecedented rate. AI-driven tools are used to identify Coronavirus outbreaks as well as forecast their nature of spread, where imaging techniques are widely used, such as CT scans and chest X-rays (CXRs). In this paper, motivated by the fact that X-ray imaging systems are more prevalent and cheaper than CT scan systems, a deep learning-based Convolutional Neural Network (CNN) model, which we call Truncated Inception Net, is proposed to screen COVID-19 positive CXRs from other non-COVID and/or healthy cases. To validate our proposal, six different types of datasets were employed by taking the following CXRs: COVID-19 positive, Pneumonia positive, Tuberculosis positive, and healthy cases into account. The proposed model achieved an accuracy of 99.96% (AUC of 1.0) in classifying COVID- 19 positive cases from combined Pneumonia and healthy cases. Similarly, it achieved an accuracy of 99.92% (AUC of 0.99) in classifying COVID-19 positive cases from combined Pneumonia, Tuberculosis and healthy CXRs. To the best of our knowledge, as of now, the achieved results outperform the existing AI-driven tools for screening COVID-19 using CXRs.

scholarly journals Optimization of the energy for Breast monochromatic absorption X-ray Computed Tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pasquale Delogu ◽  
Vittorio Di Trapani ◽  
Luca Brombal ◽  
Giovanni Mettivier ◽  
Angelo Taibi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Imaging Techniques ◽  
Fixed Dose ◽  
X Rays ◽  
Reconstruction Algorithms ◽  
Contrast Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
X Ray Computed ◽  
Dose Levels

Abstract The limits of mammography have led to an increasing interest on possible alternatives such as the breast Computed Tomography (bCT). The common goal of all X-ray imaging techniques is to achieve the optimal contrast resolution, measured through the Contrast to Noise Ratio (CNR), while minimizing the radiological risks, quantified by the dose. Both dose and CNR depend on the energy and the intensity of the X-rays employed for the specific imaging technique. Some attempts to determine an optimal energy for bCT have suggested the range 22 keV–34 keV, some others instead suggested the range 50 keV–60 keV depending on the parameters considered in the study. Recent experimental works, based on the use of monochromatic radiation and breast specimens, show that energies around 32 keV give better image quality respect to setups based on higher energies. In this paper we report a systematic study aiming at defining the range of energies that maximizes the CNR at fixed dose in bCT. The study evaluates several compositions and diameters of the breast and includes various reconstruction algorithms as well as different dose levels. The results show that a good compromise between CNR and dose is obtained using energies around 28 keV.

Design, development and first experiments on the X-ray imaging beamline at Indus-2 synchrotron source RRCAT, India

2015 ◽  
Vol 22 (6) ◽  
pp. 1531-1539 ◽  
Author(s):  
A. K. Agrawal ◽  
B. Singh ◽  
Y. S. Kashyap ◽  
M. Shukla ◽  
P. S. Sarkar ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Imaging Techniques ◽  
Phase Contrast Imaging ◽  
Design Development ◽  
Contrast Imaging ◽  
Synchrotron Source ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Micro Tomography

A full-field hard X-ray imaging beamline (BL-4) was designed, developed, installed and commissioned recently at the Indus-2 synchrotron radiation source at RRCAT, Indore, India. The bending-magnet beamline is operated in monochromatic and white beam mode. A variety of imaging techniques are implemented such as high-resolution radiography, propagation- and analyzer-based phase contrast imaging, real-time imaging, absorption and phase contrast tomographyetc. First experiments on propagation-based phase contrast imaging and micro-tomography are reported.

scholarly journals Highly porous nanoberyllium for X-ray beam speckle suppression

2015 ◽  
Vol 22 (3) ◽  
pp. 796-800 ◽  
Author(s):  
Alexander Goikhman ◽  
Ivan Lyatun ◽  
Petr Ershov ◽  
Irina Snigireva ◽  
Pawel Wojda ◽  
...  
Keyword(s):  
Spatial Coherence ◽  
Special Device ◽  
X Rays ◽  
Speckle Structure ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Phase Amplitude ◽  
Highly Porous ◽  
Effective Source

This paper reports a special device called a `speckle suppressor', which contains a highly porous nanoberyllium plate squeezed between two beryllium windows. The insertion of the speckle suppressor in an X-ray beam allows manipulation of the spatial coherence length, thus changing the effective source size and removing the undesirable speckle structure in X-ray imaging experiments almost without beam attenuation. The absorption of the nanoberyllium plate is below 1% for 1 mm thickness at 12 keV. The speckle suppressor was tested on the ID06 ESRF beamline with X-rays in the energy range from 9 to 15 keV. It was applied for the transformation of the phase–amplitude contrast to the pure amplitude contrast in full-field microscopy.

Recent progress in synchrotron radiation 3D–4D nano-imaging based on X-ray full-field microscopy

Microscopy ◽  
2020 ◽  
Vol 69 (5) ◽  
pp. 259-279
Author(s):  
Akihisa Takeuchi ◽  
Yoshio Suzuki
Keyword(s):  
Synchrotron Radiation ◽  
Fresnel Zone ◽  
Imaging Techniques ◽  
Effective Field ◽  
Current Status ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Diffraction Imaging ◽  
Nano Imaging

Abstract The advent of high-flux, high-brilliance synchrotron radiation (SR) has prompted the development of high-resolution X-ray imaging techniques such as full-field microscopy, holography, coherent diffraction imaging and ptychography. These techniques have strong potential to establish non-destructive three- and four-dimensional nano-imaging when combined with computed tomography (CT), called nano-tomography (nano-CT). X-ray nano-CTs based on full-field microscopy are now routinely available and widely used. Here we discuss the current status and some applications of nano-CT using a Fresnel zone plate as an objective. Optical properties of full-field microscopy, such as spatial resolution and off-axis aberration, which determine the effective field of view, are also discussed, especially in relation to 3D tomographic imaging.

scholarly journals ARCHAEOLOGICAL APPLICATIONS OF SYNCHROTRON RADIATION AT ELETTRA

2019 ◽  
Author(s):  
F. Zanini
Keyword(s):  
Synchrotron Radiation ◽  
Imaging Techniques ◽  
Vertical Plane ◽  
Source Size ◽  
Fine Tuning ◽  
Photon Flux ◽  
X Rays ◽  
Scientific Publications ◽  
Full Field ◽  
X Ray

The use of synchrotron radiation for the analysis of samples of historical and artistic importance (archaeology, palaeontology, conservation sciences, palaeo-environments) has been increasing over the past years, and experiments related to the study of our cultural heritage (CH) have been routinely performed at many beamlines of Elettra, the Italian synchrotron radiation facility. Fundamental parameters such as the high photon flux, the small source size and the low divergence typical of synchrotrons make it a very efficient source for a range of advanced spectroscopy and imaging techniques, adapted to the dishomogeneity and complexity of the materials under study. The continuous tunability of the source (from infrared to X-rays) is essential for techniques based on a fine tuning of the probing energy to reach high chemical sensitivity such as XANES, EXAFS, STXM, UV/VIS spectrometry. Moreover, the small source size attained in the vertical plane leads to spatial coherence of the photon source itself, giving rise to a series of imaging methods already crucial to the field. The increasing number of scientific publications shows that microfocused hard X-ray spectroscopy (absorption, fluorescence, diffraction), full-field X-ray tomography and infrared spectroscopy are the most popular synchrotron techniques in the field. The Elettra laboratory now offers a platform dedicated to CH researchers in order to support both the proposal application phase and the different steps of the experiment, from sample preparation to data analysis. We will present this activity and the main instrumental setups and experimental techniques in use at Elettra, and describe their impact for the science being applied to ancient materials using synchrotron rad

X-ray Imaging of Surface and Internal Structure

1987 ◽  
Vol 31 ◽  
pp. 25-34
Author(s):  
John C. Russ
Keyword(s):  
Internal Structure ◽  
Bragg Diffraction ◽  
X Rays ◽  
Widespread Application ◽  
X Ray ◽  
Study Materials ◽  
X Ray Imaging ◽  
Composition Variation ◽  
Hospital Emergency Room

The most familiar result from X-ray analysis is a spectrum (on a chart recording or on film), or perhaps a short list of values (concentrations, d-spacings, etc.) taken from such a spectrum. X-ray pictures are usually associated in our minds with the hospital emergency room or the dentist's office. But images formed by X-rays are also an important tool to study materials' structures. Both conventional and unconventional uses of X-rays to study structural and compositional inhomogeneities find widespread application to materials. Applications include characterization of surface topography and composition variation, as well as internal structure. The methods make use of all types of X-ray interaction with materials, including Bragg diffraction and the fluorescence of characteristic X-rays, as well as simple X-ray attenuation due to absorption and scattering.

scholarly journals Translative lens-based full-field coherent X-ray imaging

2020 ◽  
Vol 27 (1) ◽  
pp. 119-126
Author(s):  
Carsten Detlefs ◽  
Mario Alejandro Beltran ◽  
Jean-Pierre Guigay ◽  
Hugh Simons
Keyword(s):  
Numerical Aperture ◽  
Objective Lens ◽  
X Rays ◽  
Resolution Limit ◽  
Radiation Dose Rate ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Imaging Approach ◽  
Potential Benefits

A full-field coherent imaging approach suitable for hard X-rays based on a classical (i.e. Galilean) X-ray microscope is described. The method combines a series of low-resolution images acquired at different transverse lens positions into a single high-resolution image, overcoming the spatial resolution limit set by the numerical aperture of the objective lens. The optical principles of the approach are described, the successful reconstruction of simulated phantom data is demonstrated, and aspects of the reconstruction are discussed. The authors believe that this approach offers some potential benefits over conventional scanning X-ray ptychography in terms of spatial bandwidth and radiation dose rate.

scholarly journals Comparison of Rhenium and Iodine as Contrast Agents in X-Ray Imaging

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
José Carlos De La Vega ◽  
Pedro Luis Esquinas ◽  
Jovan Kaur Gill ◽  
Selin Jessa ◽  
Bradford Gill ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Atomic Number ◽  
Imaging Techniques ◽  
Absorbed Dose ◽  
X Rays ◽  
Micro Computed Tomography ◽  
Low Contrast ◽  
X Ray ◽  
X Ray Imaging ◽  
The Difference

Purpose. The majority of X-ray contrast agents (XCA) are made with iodine, but iodine-based XCA (I-XCA) exhibit low contrast in high kVp X-rays due to iodine’s low atomic number (Z = 53) and K-edge (33.1 keV). While rhenium is a transition metal with a high atomic number (Z = 75) and K-edge (71.7 keV), the utilization of rhenium-based XCA (Re-XCA) in X-ray imaging techniques has not been studied in depth. Our study had two objectives: (1) to compare both the image quality and the absorbed dose of I- and Re-XCA and (2) to prepare and image a rhenium-doped scaffold. Procedures. I- and Re-XCA were prepared and imaged from 50 to 120 kVp by Micro-computed tomography (µCT) and digital radiography and from 120 to 220 kVp by planar X-ray imaging. The scans were repeated using 0.1 to 1.6 mm thick copper filters to harden the X-ray beam. A rhenium-doped scaffold was prepared via electrospinning, used to coat catheters, and imaged at 90 kVp by µCT. Results. I-XCA have a greater contrast-to-noise ratio (CNR) at 50 and 80 kVp, but Re-XCA have a greater CNR at >120 kVp. The difference in CNR is increased as the thickness of the copper filters is increased. For instance, the percent CNR improvement of rhenium over iodine is 14.2% with a 0.6 mm thick copper filter, but it is 59.1% with a 1.6 mm thick copper filter, as shown at 120 kVp by µCT. Upon coating them with a rhenium-doped scaffold, the catheters became radiopaque. Conclusions. Using Monte Carlo simulations, we showed that it is possible to reduce the absorbed dose of high kVp X-rays while allowing the acquisition of high-quality images. Furthermore, radiopaque catheters have the potential of enhancing the contrast during catheterizations and helping physicians to place catheters inside patients more rapidly and precisely.

scholarly journals Dark-field hyperspectral X-ray imaging

2014 ◽  
Vol 470 (2165) ◽  
pp. 20130629 ◽  
Author(s):  
Christopher K. Egan ◽  
Simon D. M. Jacques ◽  
Thomas Connolley ◽  
Matthew D. Wilson ◽  
Matthew C. Veale ◽  
...  
Keyword(s):  
Materials Science ◽  
Imaging Techniques ◽  
Dark Field ◽  
Small Samples ◽  
Friction Stir Weld ◽  
Full Field ◽  
Crystallographic Preferred Orientation ◽  
X Ray ◽  
Friction Stir ◽  
X Ray Imaging

In recent times, there has been a drive to develop non-destructive X-ray imaging techniques that provide chemical or physical insight. To date, these methods have generally been limited; either requiring raster scanning of pencil beams, using narrow bandwidth radiation and/or limited to small samples. We have developed a novel full-field radiographic imaging technique that enables the entire physio-chemical state of an object to be imaged in a single snapshot. The method is sensitive to emitted and scattered radiation, using a spectral imaging detector and polychromatic hard X-radiation, making it particularly useful for studying large dense samples for materials science and engineering applications. The method and its extension to three-dimensional imaging is validated with a series of test objects and demonstrated to directly image the crystallographic preferred orientation and formed precipitates across an aluminium alloy friction stir weld section.

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