X-ray diffraction enhanced imaging study of intraocular tumors in human beings

Diffraction enhanced imaging （DEI） with edge enhancement is suitable for the observation of weakly absorbing objects. The potential ability of the DEI was explored for displaying the microanatomy and pathology of human eyeball in this work. The images of surgical specimens from malignant intraocular tumor of hospitalized patients were taken using the hard X-rays from the topography station of Beamline 4W1A at Beijing Synchrotron Radiation Facility （BSRF）. The obtained radiographic images were analyzed in correlation with those of pathology. The results show that the anatomic and pathologic details of intraocular tumors in human beings can be observed clearly by DEI for the first time, with good visualization of the microscopic details of eyeball ring such as sclera, choroids and other details of intraocular organelles. And the best resolution of DEI images reaches up to the magnitude of several tens of μm. The results suggest that it is capable of exhibiting clearly the details of intraocular tumor using DEI method.

Principle of diffraction enhanced imaging (DEI) and computed tomography based on DEI method

In the first part of this article a more general DEI equation was derived using simple concepts. Not only does the new DEI equation explain all the problems that can be done by the DEI equation proposed by Chapman, but also explains the problem that can not be explained with the old DEI equation, such as the noise background caused by the small angle scattering reflected by the analyzer. In the second part, a DEI-PI-CT formula has been proposed and the contour contrast caused by the extinction of refraction beam has been qualitatively explained, and then based on the work of Ando's group two formulae of refraction CT with DEI method has been proposed. Combining one refraction CT formula proposed by Dilmanian with the two refraction CT formulae proposed by us, the whole framework of CT algorithm can be made to reconstruct three components of the gradient of refractive index.

Intensity correlation properties of x-ray beams split with Laue diffraction

Beam splitting is one of the main approaches to achieving x-ray ghost imaging, and the intensity correlation between diffraction beam and transmission beam will directly affect the imaging quality. In this paper, we investigate the intensity correlation between the split x-ray beams by Laue diffraction of stress-free crystal. The analysis based on the dynamical theory of x-ray diffraction indicates that the spatial resolution of diffraction image and transmission image are reduced due to the position shift of the exit beam. In the experimental setup, a stress-free crystal with a thickness of hundredmicrometers-level is used for beam splitting. The crystal is in a non-dispersive configuration equipped with a double-crystal monochromator to ensure that the dimension of the diffraction beam and transmission beam are consistent. A correlation coefficient of 0.92 is achieved experimentally and the high signal-to-noise ratio of the x-ray ghost imaging is anticipated.Results of this paper demonstrate that the developed beam splitter of Laue crystal has the potential in the efficient data acquisition of x-ray ghost imaging.

First commissioning results of the coherent scattering and imaging endstation at the Shanghai soft X-ray free-electron laser facility

The Shanghai soft X-ray free-electron laser(SXFEL)user facility project started in 2016 and is expected to be open to users by 2022.It aims to deliver ultra-intense coherent femtosecond X-ray pulses to five endstations covering a range of 100–620 eV for ultrafast X-ray science.Two undulator lines are designed and constructed,based on different lasing modes:self-amplified spontaneous emission and echo-enabled harmonic generation.The coherent scattering and imaging(CSI)endstation is the first of five endstations to be commissioned online.It focuses on high-resolution single-shot imaging and the study of ultrafast dynamic processes using coherent forward scattering techniques.Both the single-shot holograms and coherent diffraction patterns were recorded and reconstructed for nanoscale imaging,indicating the excellent coherence and high peak power of the SXFEL and the possibility of‘‘diffraction before destruction’’experiments at the CSI endstation.In this study,we report the first commissioning results of the CSI endstation.

Industrial X-Ray Image Enhancement Algorithm based on AH and MSR

An X-ray image enhancement algorithm based on AH(adaptive histogram) and MSR( Multi-scale Retinex )algorithm is proposed in this paper for the industrial X-ray image, which contrast is low, and the detail features is poor. Firstly, the contrast limited adaptive histogram equalization and neighborhood algorithm is used for the image. Then the mapping is built between the image and the detail scales by the enhance function ratio rules, which is adjusted by the local contracting information. Finally, according the enhance function radios, the reconstructed image is rebuild. Compared with other image enhancement algorithms, experimental results show that our algorithm can improve the global image effectively, moreover it overcomes the visible artifacts of X-ray image. Therefore, the x-ray image becomes clearer, and a better perceptual image is acquired for the image feature recognizing and matching.

Classification COVID-19 Based on Enhancement X-Ray Images and Low Complexity Model

COVID-19 has been considered one of the recent epidemics that occurred at the last of 2019 and the beginning of 2020 that world widespread.This spread of COVID-19 requires a fast technique for diagnosis to make the appropriate decision for the treatment.X-ray images are one of the most classifiable images that are used widely in diagnosing patients’data depending on radiographs due to their structures and tissues that could be classified.Convolutional Neural Networks(CNN)is the most accurate classification technique used to diagnose COVID-19 because of the ability to use a different number of convolutional layers and its high classification accuracy.Classification using CNNs techniques requires a large number of images to learn and obtain satisfactory results.In this paper,we used SqueezNet with a modified output layer to classify X-ray images into three groups:COVID-19,normal,and pneumonia.In this study,we propose a deep learning method with enhance the features of X-ray images collected from Kaggle,Figshare to distinguish between COVID-19,Normal,and Pneumonia infection.In this regard,several techniques were used on the selected image samples which are Unsharp filter,Histogram equal,and Complement image to produce another view of the dataset.The Squeeze Net CNN model has been tested in two scenarios using the 13,437 X-ray images that include 4479 for each type(COVID-19,Normal and Pneumonia).In the first scenario,the model has been tested without any enhancement on the datasets.It achieved an accuracy of 91%.But,in the second scenario,the model was tested using the same previous images after being improved by several techniques and the performance was high at approximately 95%.The conclusion of this study is the used model gives higher accuracy results for enhanced images compared with the accuracy results for the original images.A comparison of the outcomes demonstrated the effectiveness of ourDLmethod for classifying COVID-19 based on enhanced X-ray images.

Effects of Tube Voltage on Phase-Contrast Imaging for Different Microfocus X-Ray Tubes

In the past decade, phase-contrast imaging (PCI) has become a hot research with an increased improvement of the image contrast with respect to conventional absorption radiography. In this paper, effects of tube voltage (kVp) on propagation-based phase-contrast imaging have been investigated with two types of microfocus x-ray tubes, a conventional sealed x-ray tube with the focal spot size of 13 - 20 μm and an open x-ray tube with minimum focal spot size less than 2 μm. A cooled x-ray CCD detector with the pixel size of 24 μm was used to acquire digital images. Two thin plastic sheets with different thickness were used as radiography phantoms. Two different phenomena were observed for the two x-ray tubes. For the open tube, phase-contrast effect has a slight drop with the increasing of tube voltage, however, it is opposite for the sealed tube. A further investigation indicates that the variation of focal spot size causes the abnormal result for the sealed tube. It also shows that phase-contrast effect is more sensitive to focal spot size than tube voltage.

Hard X-ray diffraction enhanced imaging only using two crystals

Different configurations for the monochroma-tor crystals and the analyzer crystals have been used in hard X-ray diffraction enhanced imaging (DEI) methods to over-come the complex task to adjust each of them to the ideal position. Here we present a very compact DEI configuration, and preliminary results of experiments performed at the Beijing Synchrotron Radiation Facility (BSRF) using only two crystals: the first one acting as monochromator and the second one as analyzer in the Bragg geometry. Refraction contrast images characterized by high contrast and spatial resolution are obtained and compared with absorption im-ages. Differences among these images will be outlined and discussed emphasizing the potential capabilities of this very simple layout that guarantees a high transmission efficiency.

An ART iterative reconstruction algorithm for computed tomography of diffraction enhanced imaging

X-ray diffraction enhanced imaging （DEI） has extremely high sensitivity for weakly absorbing low- Z samples in medical and biological fields. In this paper, we propose an Algebra Reconstruction Technique （ART） iterative reconstruction algorithm for computed tomography of diffraction enhanced imaging （DEI-CT）. An Ordered Subsets （OS） technique is used to accelerate the ART reconstruction. Few-view reconstruction is also studied, and a partial differential equation （PDE） type filter which has the ability of edge-preserving and denoising is used to improve the image quality and eliminate the artifacts. The proposed algorithm is validated with both the numerical simulations and the experiment at the Beijing synchrotron radiation facility （BSRF）.

Medical application of diffraction enhanced imaging in mouse liver blood vessels

Neovascularization is correlative with many processes of diseases, especially for tumor growth, invasion, and metastasis. What is more, these tumor microvessels are totally different from normal vessels in morphology. Therefore, observation of the morphologic distribution of microvessels is one of the key points for many researchers in the field. Using diffraction enhanced imaging （DEI）, we observed the mirocvessles with diameter of about 40 μm in mouse liver. Moreover, the refraction image obtained from DEI shows higher image contrast and exhibits potential use for medical applications.

Polynomial curve fitting method for refraction-angle extraction in diffraction enhanced imaging

X-ray diffraction sorbing low-Z sample. How enhanced imaging （DEI） is applied to extract phase information from to inspect internal structures of weakly abraw images measured in different positions of rocking curve is the key problem of DEI. In this paper, we present an effective extraction method called polynomial curve fitting method, in order to extract accurate information angular in a fast speed. It is compared with the existing methods such as multiple-images statistical method and Gaussian curve fitting method. The experiments results on a plastic cylinder and a black ant at the Beijing Synchrotron Radiation Facility prove that the polynomial curve fitting method can obtain most approximate refraction-angle values and its computation speed is 10 times faster than the Gaussian curve fitting method.

Assessing no-surgical treatment response in bronchogenic carcinoma with contrast material-enhanced computed tomography

Objective:The aim of the study was to evaluate the efficacy of contrast material-enhanced computed tomography(CT) in assessing no-surgical treatment response in bronchogenic carcinoma.Methods:The 67 patients with bronchogenic carcinoma after no-surgical treatment underwent two-phase contrast material-enhanced computed tomography.Two spiral CT scans were obtained at 25 and 90 s respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 mL/s by using an autoinjector.Precontrast and postcontrast attenuation values on every scan were recorded and peak height was calculated.Enhancement pattern was evaluated on the image obtained at 25 and 90 s after injection of contrast medium.Results:Precontrast attenuation value,postcontrast attenuation values at 25 and 90 s were(41.26 ± 7.77) Hu,(56.45 ± 10.48) Hu,(70.82 ± 11.99) Hu,respectively.No statistically significant difference in precontrast attenuation was found between our results in this study and the results in our old study(mean precontrast attenuation 40.70 Hu) which was obtained in cases without any therapy(t = 0.593,P = 0.555﹥0.05).Peak height of bronchogenic carcinoma after no-surgical treatment [(29.40 ± 10.73) Hu] were significantly lower than that of bronchogenic carcinoma without any therapy obtained in our old study(mean peak height 35.79 Hu)(t =-4.874,P = 0.001 < 0.05).The 39 among 67 cases appeared homogeneous enhancement at 90 s.At 25 s,there were 26 cases with inhomogeneous enhancement,9 cases with homogeneous enhancement,2 cases with central enhancement,and 2 cases with peripheral enhancement among the 39 cases.Conclusion:Peak heights can reflect the blood supply of bronchogenic carcinoma and might be an index for evaluation of no-surgical treatment response in bronchogenic carcinoma.

Ultrahard X-ray multifunctional application beamline at the SSRF

The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation Facility.The primary X-ray techniques used at the beamline are high-energy X-ray diffraction and imaging using white and monochromatic light.The main scientific objectives of ultrahard X-ray beamlines are focused on two research areas.One is the study of the structural properties of Earth’s interior and new materials under extreme high-temperature and high-pressure conditions,and the other is the characterization of materials and processes in near-real service environments.The beamline utilizes a superconducting wiggler as the light source,with two diamond windows and SiC discs to filter out low-energy light(primarily below 30 keV)and a Cu filter assembly to control the thermal load entering the subsequent optical components.The beamline is equipped with dual monochromators.The first was a meridional bending Laue monochromator cooled by liquid nitrogen,achieving a full-energy coverage of 30-162 keV.The second was a sagittal bending Laue monochromator installed in an external building,providing a focused beam in the horizontal direction with an energy range of 60-120 keV.There were four experimental hutches:two large-volume press experimental hutches(LVP1 and LVP2)and two engineering material experimental hutches(ENG1 and ENG2).Each hutch was equipped with various near-real service conditions to satisfy different requirements.For example,LVP1 and LVP2 were equipped with a 200-ton DDIA press and a 2000-ton dual-mode(DDIA and Kawai)press,respectively.ENG1 and ENG2 provide in situ tensile,creep,and fatigue tests as well as high-temperature conditions.Since June 2023,the BL12SW has been in trial operation.It is expected to officially open to users by early 2024.

Application of Synchrotron X-Ray Imaging and Diffraction in Additive Manufacturing:A Review

Additive manufacturing(AM)is a rapid prototyping technology based on the idea of discrete accumulation which off ers an advantage of economically fabricating a component with complex geometries in a rapid design-to-manufacture cycle.However,various internal defects,such as balling,cracks,residual stress and porosity,are inevitably occurred during AM due to the complexity of laser/electron beam-powder interaction,rapid melting and solidification process,and microstructure evolution.The existence of porosity defects can potentially deteriorate the mechanical properties of selective laser melting(SLM)components,such as material stiff ness,hardness,tensile strength,and fatigue resistance performance.Synchrotron X-ray imaging and diffraction are important non-destructive means to elaborately characterize the internal defect characteristics and mechanical properties of AM parts.This paper presents a review on the application of synchrotron X-ray in identifying and verifying the quality and requirement of AM parts.Defects,microstructures and mechanical properties of printed components characterized by synchrotron X-ray imaging and diffraction are summarized in this review.Subsequently,this paper also elaborates on the online characterization of the evolution of the microstructure during AM using synchrotron X-ray imaging,and introduces the method for measuring AM stress by X-ray diffraction(XRD).Finally,the future application of synchrotron X-ray characterization in the AM is prospected.

Recent Progress of Synchrotron X-Ray Imaging and Diffraction on the Solidification and Deformation Behavior of Metallic Materials

Characterizing the microstructure and deformation mechanism associated with the performances and properties of metallic materials is of great importance in understanding the microstructure-property relationship.The past few decades have witnessed the rapid development of characterization techniques from optical microscopy to electron microscopy,although these conventional methods are generally limited to the sample surface because of the intrinsic opaque nature of metallic materials.Advanced synchrotron radiation(SR)facilities can produce X-rays with strong penetrability and high spatiotemporal resolution,and thereby enabling the non-destructive visualization of full-field structural information in three dimensions.Tremendous endeavors were devoted to the 3 rd generation SR over the past three decades,in which X-ray beams have been focused down to 100 nm.In this paper,recent progresses on SR-related characterization technologies were reviewed,with particular emphases on the fundamentals of synchrotron X-ray imaging and synchrotron X-ray diffraction,as well as their applications in the in situ observations of material preparation(e.g.,in situ dendrite growth during solidification)and service under extreme environment(e.g.,in situ mechanics).Future innovations toward next-generation SR and newly emerging SRbased technologies such as dark-field X-ray microscopy and Bragg coherent X-ray diffraction imaging were also advocated.

Soft X-ray ptychography method at SSRF

Ptychography is a diffraction-based X-ray microscopy technique in which an extended sample is scanned by a coherent beam with overlapped illuminated areas and complex transmission function of the sample is obtained by applying iterative phase retrieval algorithms to the diffraction patterns recorded at each scanned position.It permits quantitatively imaging of non-crystalline specimens at a resolution limited only by the X-ray wavelength and the maximal scattering angle detected.In this paper,the development of soft X-ray ptychography method at the BL08U1 A beamline of Shanghai Synchrotron Radiation Facility is presented.The experimental setup,experimental parameters selection criteria,and post-experimental data analyzing procedures are presented in detail with a prospect of high-resolution image reconstruction in real time.The performance of this newly implemented method is demonstrated through the measurements of a resolution test pattern and two real samples:Pt-Co alloy nanoparticles and a breast cancer cell.The results indicate that strong scattering specimens can be reconstructed to sub-20 nm resolution,while a sub-25 nm resolution for biological specimens can be achieved.

Rietveld quantification of γ-C_2S conversion rate supported by synchrotron X-ray diffraction images

The pure γ-Ca2SiO4 （]t-C2S） phase was prepared at 1623 K of calcining temperature, 10 h of holding time and furnace cooling. The 13-C2S phase was obtained through γ-C2S conversion with the following calcination system which was adopted at 1473 K of calcining temperature, 1 h of holding time and then water-cooling. The conversion rate of γ-C2S was studied by the Rietveld quantitative laboratory X-ray powder diffraction supported by synchrotron X-ray diffraction images. The refinement results show that the final conversion rate of γ-C2S is higher than 92%. The absolute error of the γ-C2S conversion rate between two Rietveld refinements （sample with or without α-Al2O3） is 3.6%, which shows that the Rietveld quantitative X-ray diffraction analysis is an appropriate and accurate method to quantify the γ-C2S conversion rate.

Optimization of the in-line X-ray phase-contrast imaging setup considering edge-contrast enhancement and spatial resolution

Employing the approximation theory based on refraction and the definition of the total pointspread-function of the imaging system, the variation in the edge contrast of simple model samples is discussed with different source-to-sample and sample-to-detector distances, which actually means different spatial resolutions of the imaging system. The experiments were carried out with the Beamline 4W1A imaging setup at the Beijing Synchrotron Radiation Facility for simple model and insect samples. The results show that to obtain clear phase-contrast images of biologic tissues for the X-ray in-line imaging setup, with determined parameters such as the size of the X-ray source, the pixel size of the detector and the fixed source-to-sample distance, there is a range of optimized sample-to-detector distances. The analysis method discussed in this article can be helpful in optimizing the setup of X-ray in-line phase-contrast imaging.

Enhanced quantitative X-ray phase-contrast images using Foucault differential filters

Several X-ray phase visualization methods are being real- ized for imaging of phase objects, such as biological and polymeric specimens. Grating-based phase-contrast imaging using a source-grating-attached X-ray tube that provides partially coherent X rays is one of the most successful methods in this field.

Preliminary assessing no-surgical treatment response in bronchogenic carcinoma with changes in enhancement pattern

Objective： The aim of this study was to evaluate the efficacy of changes in enhancement pattern in assessing no-surgical treatment response in bronchogenic carcinoma preliminarily. Methods Thirty-three patients with bronchogenic carcinoma underwent two-phase contrast material-enhanced computed tomography prior to and after stopping no-surgical treatment more than one-month respectively. Two spiral CT scans were obtained at 25 and 90 s respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 3 mL/s by using an autoinjector. The sum of the tumor longest diameters （LD） prior to treatment, after treatment and the sum of the post-treatment tumor enhancement area LD on the images obtained at 90 s after injection of contrast medium were recorded, Precontrast and postcontrast attenuation on every scan was recorded and peak height was calculated. The significance of the difference among groups was analyzed by means of ANOVA, student t test and chi-square test. Results： The sum of the tumor LD prior to treatment, that of after treatment and the sum of the post-treatment tumor enhancement area LD on the images obtained at 90 s after injection of contrast medium were （4.49 ± 1.32）, （4.05 ± 1.63）, （3.36 ± 1.22） cm respectively and there were statistically significant dif- ferences among them （f= 5.467, P = 0.006）. The sum of the tumor LD prior to treatment was significantly higher than that of the post-treatment tumor enhancement area （P = 0.001）. No statistically significant difference in the sum of the tumor LD was found between the pre- treatment and the post-treatment （P = 0.207）. There was no statistically significant difference between the sum of the tumors LD and that of tumor enhancement area after treatment （P = 0.086）. The response rate （RR） （21.21%） according to changes in sum of the tumor LD was significantly lower than that （30.30%） according to changes in the sum of the post-treatment tumor enhancement area LD （x2 = 15.12, P 〈 0.05）, and the progressive diseases （PD） rate （21.21%） was significantly higher than that （12.12%; X2 = 14.12, P 〈 0.05）. No statistically significant difference was found between precontrast attenuation prior to treatment [（41.77±7.03） HU] and that after treatment [（41.89 ± 7.63） HU; t = 0.335, P = 0.740 〉 0.05]. Peak height of bronchogenic carcinoma prior to treatment [（36.50 ± 11.21） HU] were significantly higher than that after treatment [（29.91 ± 10.35） HU; t = 10.081, P = 0.001]. Conclusion： Therapeutic effect may be underestimated with use of changes in sum of the tumor LD. The changes in sum of tumor enhancement area LD in addition to peak height is suggested to be used in assessing no-surgical.treatment response in bronchogenic carcinoma.