X-ray Imaging Method Research Articles

Grating-based spatial harmonic frequency X-ray imaging for qualitative and quantitative studies of granular and liquids materials

Grating-based spatial harmonic frequency X-ray imaging method allows the individual reconstruction of attenuation, scattering and phase-contrast X-ray images with a single exposure of the samples. In this work, the influence of the attenuation grating features (visibility and projected period) and sample features (thickness and grains sizes) on the reconstructed images were experimentally explored. Results showed that fringe visibility higher than 15% are fundamental for the proper image reconstruction. Even though reconstructed imagens are low spatial resolution (140–340 μm), they presented higher signal-to-noise ratio (SNR 85–700) than conventional images (SNR 14–39), due to the Fourier analyses procedure. Scattering could not resolve the individual grains structures, nevertheless, they revealed the presence of structures smaller than the image system resolution. Finally, it is presented that combining attenuation and scattering signals allows differentiation among the different grain sizes in granular materials and different liquids that appears similar in conventional images.

Denoising method for X-ray images with poisson-Gaussian noise based on a new threshold function and shearlet transform

BackgroundX-ray imaging has been applied in various fields. However, the noise in X-ray images reduces the image quality and affects subsequent detection. AimsA denoising method is developed to solve the problem of the Poisson-Gaussian mixed noise caused by X-ray imaging. Methodology: A new threshold function and an improved threshold are proposed in this paper. Furthermore, an improved denoising method, namely the improved generalized Anscombe with shearlet transform (improved GA-ST), is developed based on the above proposed algorithms. After theoretical derivation, experiments and parameter analysis, the proposed method is applied to actual X-ray images. ResultsThe results show that the new threshold function is continuous, asymptotic, and has no inherent deviation, which solves the problems existing in traditional threshold functions. In addition, the improved GA-ST method can reduce Poisson-Gaussian mixed noise at different levels. As for actual X-ray images, the improved GA-ST method outperforms the other methods, and the BRISQUE descent ratios all exceed 25%. ConclusionsThe improved GA-ST method proposed in this paper can effectively reduce the noise in X-ray images and meet the requirements of actual applications based on MATLAB platform.

Investigation of radiation knowledge and awareness among healthcare professionals in Mogadishu, Somalia: a single-center survey study

Objective: The aim of this study was to evaluate the radiation knowledge and awareness levels of healthcare workers working in a single center in Mogadishu, Somalia, in terms of age, gender and education levels of the participants. Materials and methods: The research involved 274 healthcare professionals, comprising volunteer physician and other healthcare personnel working at the Somali-Turkey Recep Tayyip Erdoğan Training and Research Hospital in Mogadishu. The face-to-face questionnaire consists of 13 questions covering radiation-sensitive or resistant tissues, radiation status of medical imaging devices, biological effects of radiation, ionizing and non-ionizing radiation symbols and radiation protection principles. The study was limited to the health personnel in the hospital. The survey had 274 participants, comprising 126 (46%) women and 148 (54%) men. Of these, 82 (29.9%) were physicians and 192 (70.1%) were other healthcare professionals. Results: It was found that health workers under the age of thirty demonstrated a significantly higher level of knowledge about radiation protection principles than their counterparts over the age of thirty (p = 0.003). Similarly, it was observed that the level of awareness regarding the extent of knowledge about radiation protection was higher in health workers under thirty years of age than in those over thirty years of age (p: 0.001). It was found to be statistically significant that males were more aware of the potential harms of radiation than females (p: 0.004). It was found to be statistically significant that men were more aware of the radiation content of mammography and X-ray imaging methods than women (p: 0.002 and p: 0.029, respectively). Conclusions: To enhance the number of healthcare professionals in Mogadishu, Somalia, who are aware of the risks associated with radiation and the methods for its mitigation, it was postulated that a comprehensive radiation information and awareness training program could be beneficial.

Structures of Liquid-Liquid Interfaces in Partially Miscible Systems Revealed by Soft X-ray Imaging.

The properties of liquid-liquid interfaces are intricately linked to its structure, with a particular focus on the concentration distribution within the interface. To obtain precise information regarding the concentration distribution, we have developed a high-resolution soft X-ray imaging method for liquid-liquid interfaces. This work focused on representative partially miscible systems, analyzing the interfacial concentration distribution profiles of water-alkanols under both steady-state and dynamic processes, and obtaining the diffusion coefficients of different water concentrations in alkanols. Significant disparities in concentration distributions and the concentration-related diffusion coefficients were observed despite comparable diffusion distances within the same system across different states. Meanwhile, it was found that alkanols exhibit adsorption phenomena at the interface. This newfound knowledge serves as a crucial stepping stone toward a deeper understanding of partially miscible systems. Our study opens a way to explore liquid-liquid interface information with high-resolution.

A ROI Extraction Method for Wrist Imaging Applied in Smart Bone-Age Assessment System.

Bone Age (BA) is reckoned to be closely associated with the growth and development of teenagers, whose assessment highly depends on the accurate extraction of the reference bone from the carpal bone. Being uncertain in its proportion and irregular in its shape, wrong judgment and poor average extraction accuracy of the reference bone will no doubt lower the accuracy of Bone Age Assessment (BAA). In recent years, machine learning and data mining are widely embraced in smart healthcare systems. Using these two instruments, this article aims to tackle the aforementioned problems by proposing a Region of Interest (ROI) extraction method for wrist X-ray images based on optimized YOLO model. The method combines Deformable convolution-focus (Dc-focus), Coordinate attention (Ca) module, Feature level expansion, and Efficient Intersection over Union (EIoU) loss all together as YOLO-DCFE. With the improvement, the model can better extract the features of irregular reference bone and reduce the potential misdiscrimination between the reference bone and other similarly shaped reference bones, improving the detection accuracy. We select 10041 images taken by professional medical cameras as the dataset to test the performance of YOLO-DCFE. Statistics show the advantages of YOLO-DCFE in detection speed and high accuracy. The detection accuracy of all ROIs is 99.8%, which is higher than other models. Meanwhile, YOLO-DCFE is the fastest of all comparison models, with the Frames Per Second (FPS) reaching 16.

Correction for X-Ray Scatter and Detector Crosstalk in Dark-Field Radiography.

Dark-field radiography, a new X-ray imaging method, has recently been applied to human chest imaging for the first time. It employs conventional X-ray devices in combination with a Talbot-Lau interferometer with a large field of view, providing both attenuation and dark-field radiographs. It is well known that sample scatter creates artifacts in both modalities. Here, we demonstrate that also X-ray scatter generated by the interferometer as well as detector crosstalk create artifacts in the dark-field radiographs, in addition to the expected loss of spatial resolution. We propose deconvolution-based correction methods for the induced artifacts. The kernel for detector crosstalk is measured and fitted to a model, while the kernel for scatter from the analyzer grating is calculated by a Monte-Carlo simulation. To correct for scatter from the sample, we adapt an algorithm used for scatter correction in conventional radiography. We validate the obtained corrections with a water phantom. Finally, we show the impact of detector crosstalk, scatter from the analyzer grating and scatter from the sample and their successful correction on dark-field images of a human thorax.

Adaptive multi-beam X-ray ptychography

Ptychography has evolved as an important method for nanoscale X-ray imaging with synchrotron radiation. Recently, it has been proposed to work with multiple beams in parallel. The main advantage of so-called multi-beam ptychography is that larger areas can be imaged much faster than with a conventional single beam scan. We introduce adaptive multi-beam ptychography performed with two Fresnel zone plates, placed one behind the other. In contrast to previous demonstrations of multi-beam ptychography, our optical scheme allows for adapting the spatial beam separation to the needs of the sample under investigation, relaxes thickness requirements on zone plates and is straightforward to implement. Moreover, it is simple to switch between single and multi-beam illumination during the same experiment. This opens the possibility of combining large and fast overview scans with detailed imaging of certain regions of interests.

High-speed continuous X-ray imaging method based on SiPM auto-encoding detector

High-speed X-ray imaging can be used to observe the internal evolution of objects in the microsecond range. However, obtaining data and processing images continuously are difficult when the speed of X-ray imaging is more than one million frames per second (fps). The novel method of high-speed X-ray imaging, which is based on a SiPM auto-encoding detector, was proposed. The different response to X-ray is realized by adjusting the bias voltage of different pixels to encode the analog signals. The analog signals from multiple SiPM pixels are simplified into a single signal. In this way, SiPM is constructed as the SiPM auto-encoding detector, which greatly reduces the amount of analog signals to be sampled for each frame of X-ray image, and then the image is reconstructed in the upper computer. The feasibility of the imaging method was verified by coupling the pixelated SiPM and lutetium-ytterbium scintillation crystals to construct a SiPM auto-encoding detector. Six patterns were exposed when pulsed X-rays were performed at frequencies of 100 and 500 kHz. Then, the number of image pixels was compressed from 16 to 4. The peak signal-to-noise ratio of the reconstructed images was above 41, and the structural similarity was above 0.99. Experimental results demonstrated that the speed of continuous X-ray imaging reached 500, 000 fps for six kinds of 4 × 4 pixel patterns. This method can be applied to improve the speed of high-speed continuous X-ray imaging.

In vivo X-ray microtomography locally affects stem radial growth with no immediate physiological impact.

Microcomputed tomography (µCT) is a nondestructive X-ray imaging method used in plant physiology to visualize in situ plant tissues that enables assessments of embolized xylem vessels. Whereas evidence for X-ray-induced cellular damage has been reported, the impact on plant physiological processes such as carbon (C) uptake, transport, and use is unknown. Yet, these damages could be particularly relevant for studies that track embolism and C fluxes over time. We examined the physiological consequences of µCT scanning for xylem embolism over 3 mo by monitoring net photosynthesis (Anet), diameter growth, chlorophyll (Chl) concentration, and foliar nonstructural carbohydrate (NSC) content in 4 deciduous tree species: hedge maple (Acer campestre), ash (Fraxinus excelsior), European hornbeam (Carpinus betulus), and sessile oak (Quercus petraea). C transport from the canopy to the roots was also assessed through 13C labeling. Our results show that monthly X-ray application did not impact foliar Anet, Chl, NSC content, and C transport. Although X-ray effects did not vary between species, the most pronounced impact was observed in sessile oak, marked by stopped growth and stem deformations around the irradiated area. The absence of adverse impacts on plant physiology for all the tested treatments indicates that laboratory-based µCT systems can be used with different beam energy levels and doses without threatening the integrity of plant physiology within the range of tested parameters. However, the impacts of repetitive µCT on the stem radial growth at the irradiated zone leading to deformations in sessile oak might have lasting implications for studies tracking plant embolism in the longer-term.

Imaging extended single crystal lattice distortion fields with multi-peak Bragg ptychography

Recent advances in phase-retrieval-based x-ray imaging methods have demonstrated the ability to reconstruct 3D distortion vector fields within a nanocrystal by using coherent diffraction information from multiple crystal Bragg reflections. However, these works do not provide a solution to the challenges encountered in imaging lattice distortions in crystals with significant defect content that result in phase wrapping. Moreover, these methods only apply to isolated crystals smaller than the x-ray illumination, and therefore cannot be used for imaging of distortions in extended crystals. We introduce multi-peak Bragg ptychography which addresses both challenges via an optimization framework that combines stochastic gradient descent and phase unwrapping methods for robust image reconstruction of lattice distortions and defects in extended crystals. Our work uses modern automatic differentiation toolsets so that the method is easy to extend to other settings and easy to implement in high-performance computers. This work is particularly timely given the broad interest in using the increased coherent flux in fourth-generation synchrotrons for innovative material research.

Research on Multi-Scale Fusion Method for Ancient Bronze Ware X-ray Images in NSST Domain

X-ray imaging is a valuable non-destructive tool for examining bronze wares, but the complexity of the coverings of bronze wares and the limitations of single-energy imaging techniques often obscure critical details, such as lesions and ornamentation. Therefore, multiple imaging is required to fully present the key information of bronze artifacts, which affects the complete presentation of information and increases the difficulty of analysis and interpretation. Using high-performance image fusion technology to fuse X-ray images of different energies into one image can effectively solve this problem. However, there is currently no specialized method for the fusion of images of bronze artifacts. Considering the special requirements for the restoration of bronze artifacts and the existing fusion framework, this paper proposes a new method. It is a novel multi-scale morphological gradient and local topology-coupled neural P systems approach within the Non-Subsampled Shearlet Transform domain. It addresses the absence of a specialized method for image fusion of bronze artifacts. The method proposed in this paper is compared with eight high-performance fusion methods and validated using a total of six evaluation metrics. The results demonstrate the significant theoretical and practical potential of this method for advancing the analysis and preservation of cultural heritage artifacts.

X-ray with finite element analysis is a viable alternative for MRI to predict knee osteoarthritis: Data from the Osteoarthritis Initiative.

Magnetic resonance imaging (MRI) offers superior soft tissue contrast compared to clinical X-ray imaging methods, while also providing accurate three-dimensional (3D) geometries, it could be reasoned to be the best imaging modality to create 3D finite element (FE) geometries of the knee joint. However, MRI may not necessarily be superior for making tissue-level FE simulations of internal stress distributions within knee joint, which can be utilized to calculate subject-specific risk for the onset and development of knee osteoarthritis (KOA). Specifically, MRI does not provide any information about tissue stiffness, as the imaging is usually performed with the patient lying on their back. In contrast, native X-rays taken while the patient is standing indirectly reveal information of the overall health of the knee that is not seen in MRI. To determine the feasibility of X-ray workflow to generate FE models based on the baseline information (clinical image data and subject characteristics), we compared MRI and X-ray-based simulations of volumetric cartilage degenerations (N = 1213) against 8-year follow-up data. The results suggest that X-ray-based predictions of KOA are at least as good as MRI-based predictions for subjects with no previous knee injuries. This finding may have important implications for preventive care, as X-ray imaging is much more accessible than MRI.

Pore structure characterization and effective thermal conductivity modeling of fibrous building thermal insulation materials based on X-ray tomography

The existing structural characterization methods of building materials as well as thermal conductivity calculation models can not be directly applied when considering fibrous building thermal insulation materials with intricate skeletons. In this study, rock wool is considered the research object, and the X-ray tomography method is used to characterize the pore structure and extract structural parameters. Based on the actual pore morphology of the material, the pores in the representative elementary volume (REV) are reasonably assumed to be cubic. Additionally, considering the contact thermal resistance of fibers and the randomness of pore distribution, the curved pattern of heat conduction pathway with the ever-changing diameter is reasonably simplified into a series-parallel form of the curved heat chain with the same diameter. On this basis, the fractal models of effective thermal conductivity are established in horizontal and vertical directions. Finally, a modified formula for the effective thermal conductivity calculation of fiber thermal insulation materials is proposed, taking into account the influence of fiber orientation on the material thermal conductivity. It was shown that the relative deviation between the calculated correction value and the experimental value of the effective thermal conductivity is all less than 16.13%.

Highlighting the effects of gamma irradiation of the brain through non-conventional X-ray imaging

Whole brain irradiation is largely used as an alternative radiotherapy of brain tumors that cannot be eliminated by surgery so the effects of ionizing radiation on brain healthy tissue represents an important research domain. The aim of this study is to evaluate the irradiation effects on in vitro brain tissue spheroids models as well as the whole mouse brain using standard cellular biology assays and a multi-energy X-ray imaging technique. The spheroids irradiated with gamma rays (dose between 0–30 Gy) and treated with biocompatible nanoparticles consisting of concentrations between 0–100 μM proved to be morphologically stable and with a high radio-resistance. The reactive oxygen species concentration and the γ-H2AX foci number increase with the irradiation dose, as expected. The X-ray imaging with dual-energy technique method proposed here was able to differentiate between irradiated and control samples (whole brain). Concluding, our results proved the expected effects of ionizing radiation on brain tissue. The dual-energy X-ray imaging method tested here appears as a promising method for characterizing the ionizing radiation effects on the whole brain level.

State-of-the-art multimodal scanning hard X-ray imaging and tomography sheds light at multiple length-scales on biomineralization related processes

Biomineralization is a widespread process among living organisms, playing a significant role in the formation and preservation of geological structures, biogeochemical cycles, regulation of ocean chemistry, and carbon sequestration. Moreover pathological biomineralization has a huge impact on human health. The growth of biominerals provides a rich area for research at multiple length-scales since they have controlled hierarchical structures from nano-to macroscopic scales. Here, we provide an overview on the potentials of the state-of-the-art scanning hard X-ray imaging and tomography methods developed at the NANOSCOPIUM beamline at Synchrotron Soleil in such studies. Multimodal scanning imaging provides simultaneous information on the elemental composition by X-ray fluorescence (XRF) spectrometry, on the sample morphology by absorption contrast imaging, on the crystalline structure by X-ray diffraction, and on the luminescence characteristics by X-ray Excited Optical Luminescence. As illustrated through diverse research cases about biomineralization in stromatolites and pathological calcification, such a versatile portfolio of X-ray imaging techniques provides unique complementary information to conventional laboratory techniques on biominerals and the underlying mineral precipitation processes.

Dynamic X-ray speckle-tracking imaging with high-accuracy phase retrieval based on deep learning.

Speckle-tracking X-ray imaging is an attractive candidate for dynamic X-ray imaging owing to its flexible setup and simultaneous yields of phase, transmission and scattering images. However, traditional speckle-tracking imaging methods suffer from phase distortion at locations with abrupt changes in density, which is always the case for real samples, limiting the applications of the speckle-tracking X-ray imaging method. In this paper, we report a deep-learning based method which can achieve dynamic X-ray speckle-tracking imaging with high-accuracy phase retrieval. The calibration results of a phantom show that the profile of the retrieved phase is highly consistent with the theoretical one. Experiments of polyurethane foaming demonstrated that the proposed method revealed the evolution of the complicated microstructure of the bubbles accurately. The proposed method is a promising solution for dynamic X-ray imaging with high-accuracy phase retrieval, and has extensive applications in metrology and quantitative analysis of dynamics in material science, physics, chemistry and biomedicine.

A New Method for Synchrotron Radiation X-Ray Imaging of Micro-Objects using Nanofocusing Optics and Tomography

A New Method for Synchrotron Radiation X-Ray Imaging of Micro-Objects using Nanofocusing Optics and Tomography

A pediatric bone age assessment method for hand bone X-ray images based on dual-path network

A pediatric bone age assessment method for hand bone X-ray images based on dual-path network

Interleaved x-ray imaging: A method for simultaneous acquisition of quantitative and diagnostic digital subtraction angiography.

Flow altering angiographic procedures suffer from ill-defined, qualitative endpoints. Quantitative digital subtraction angiography (qDSA) is an emerging technology that aims to address this issue by providing intra-procedural blood velocity measurements from time-resolved, 2D angiograms. To date, qDSA has used 30 frame/s DSA imaging, which is associated with high radiation dose rate compared to clinical diagnostic DSA (up to 4 frame/s). The purpose of this study is to demonstrate an interleaved x-ray imaging method which decreases the radiation dose rate associated with high frame rate qDSA while simultaneously providing low frame rate diagnostic DSA images, enabling the acquisition of both datasets in a single image sequence with a single injection of contrast agent. Interleaved x-ray imaging combines low radiation dose image frames acquired at a high rate with high radiation dose image frames acquired at a low rate. The feasibility of this approach was evaluated on an x-ray system equipped with research prototype software for x-ray tube control. qDSA blood velocity quantification was evaluated in a flow phantom study for two lower dose interleaving protocols (LD1: and LD2: ) and one conventional (full dose) protocol ( . Dose was measured at the interventional reference point. Fluid velocities ranging from 24 to 45cm/s were investigated. Gold standard velocities were measured using an ultrasound flow probe. Linear regression and Bland-Altman analysis were used to compare ultrasound and qDSA. The LD1 and LD2 interleaved protocols resulted in dose rate reductions of -67.7% and -85.5%, compared to the full dose qDSA scan. For the full dose protocol, the Bland-Altman limits of agreement (LOA) between qDSA and ultrasound velocities were [0.7, 6.7] cm/s with a mean difference of 3.7cm/s. The LD1 interleaved protocol results were similar (LOA: [0.3, 6.9] cm/s, bias: 3.6cm/s). The LD2 interleaved protocol resulted in slightly larger LOA: [-2.5, 5.5] cm/s with a decrease in the bias: 1.5cm/s. Linear regression analysis showed a strong correlation between ultrasound and qDSA derived velocities using the LD1 protocol, with a of , a slope of and an offset of cm/s. Similar values were also found for the LD2 protocol, with a of , a slope of and an offset of cm/s. The interleaved method enables simultaneous acquisition of low-dose high-rate images for intra-procedural blood velocity quantification (qDSA) and high-dose low-rate images for vessel morphology evaluation (diagnostic DSA).

Taking into account a priori information in the iterative reconstruction of images of foundry products

Methods of restoring images and properties of non-destructive testing objects based on solving inverse problems (problems of restoring distribution functions of unknown characteristics of an object based on the results of indirect measurements) are considered. Management methods are based on solving inverse problems and allow you to get the most complete information about the distributed properties of an object. The need to attract additional information imposes serious restrictions on the development of universal applied algorithms for solving incorrectly set tasks. As a rule, individual additional information is available for each specific non-destructive testing task. An effective numerical algorithm for solving an incorrectly posed problem should be focused on taking this information into account at each stage of the solution search. When solving an applied problem, it is also necessary that the algorithm corresponds to both the measuring capabilities and the capabilities of available computing tools. The problem of low-projection X-ray tomography is always associated with a lack of initial data and can only be solved using a priori information. To introduce the necessary additional information into the numerical algorithm, the methods of iterative reconstruction of tomographic images are identified as the most suitable. One of the approaches to the presentation of this kind of information is described. A practical solution to this problem will expand the scope of the X-ray tomography method.