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- 2018
- target detection
- infrared image
- lucas–kanade method (LK)
- local contrast method (LCM)
- Optoelectronic Information Science and Engineering
- University of Chinese Academy of Science
- Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Science
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Gold-tagged Polymeric Nanoparticles with Spatially Controlled Composition for Enhanced Detectability in Biological Environments
摘要： Organic nanoparticles offer the advantage of high biocompatibility for biomedical applications but suffer frequently from poor visibility in biological environments. While fluorescent-labeling is convenient and allows for fast and extensive histological analysis, fluorescence imaging and quantitative analysis are limited by low resolution and significantly hindered by tissue auto-fluorescence. Labeling of polymeric nanoparticles with an additional gold tag would allow for high resolution imaging via transmission electron microscopy (TEM) and for quantification of particles by inductively coupled plasma optical emission spectrometry (ICP-OES). However, spatially uncontrolled gold-tagging can cause significant fluorescence quenching. To overcome this restraint, 2.2 nm gold nanoparticles were introduced at the interface between the hydrophobic fluorophore-loaded core and the hydrophilic shell of polymeric nanoparticles. Due to the small size of gold labels and the spatially controlled stratified composition of hybrid nanoparticles, fluorescence quenching by gold tags was minimized to 15.1%, allowing for concomitant detection of both labels via optical microscopy after enhancement of the gold tags. Multilayered hybrid nanoparticles exhibited outstanding detectability by transmission electron microscopy, even without additional sample staining. Furthermore, they were capable of producing remarkable image contrast inside cells after gold or silver enhancement. The interfacial gold layer increased the hydrodynamic particle size only marginally from 71.8 to 89.5 nm and had no negative impact on biocompatibility in vitro. The gold content (0.75% m/m) is sufficiently high for future quantification in tissues after systemic administration. With their clean-cut structure and superior detectability, multilayered hybrid nanoparticles constitute an outstanding blueprint and a precious tool for the development of nanomedicines.
关键词： gold,polymeric nanoparticles,hybrid,TEM,PLGA,contrast agent
更新于2025-11-21 11:24:58
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Simultaneous enhancement of red upconversion luminescence and CT contrast of NaGdF <sub/>4</sub> :Yb,Er nanoparticles <i>via</i> Lu <sup>3+</sup> doping
摘要： To date, lanthanide-doped upconversion nanoparticles (UCNPs) have been widely reported as a promising CT contrast agent because they have high atomic numbers and big X-ray attenuation coefficient values. However, it is still a challenge to fabricate a simple multimodal imaging probe with improved image quality for early cancer diagnosis in clinical medicine. Herein, ultra-small, uniform and monodisperse β-NaGdF4:Yb,Er,X% Lu (X = 0, 1, 2.5, 4, 6, 7.5) UCNPs were prepared through a solvothermal method with high-level modulation of both the phase and morphology. Meanwhile, a remarkably enhanced red upconversion luminescence (UCL) in the β-NaGdF4:Yb,Er,X% Lu NPs was successfully realized via Lu3+ doping. It is found that as the content of Lu3+ increases from 0 to 7.5 mol%, the UCL intensity of the red emission first increases and then decreases, with the optimum doping content of Lu3+ ions of 2.5 mol%. The red UCL enhancement is ascribed to the change of the Yb–Er interionic distance controlling the Yb–Er energy transfer rate and the distortion of the local environment of Er3+ ions influencing the 4f–4f transition rates of Er3+ ions, which has been further confirmed by the experimental check of the crystallographic phase and by photoluminescence spectroscopy employing Eu3+ as the structural probe, respectively. More importantly, after being modified with the HS-PEG2000-NH2 ligand, the NH2-PEGylated-NaGdF4:Yb,Er,X% Lu NPs exhibited low cytotoxicity, high biocompatibility, and remarkably enhanced contrast performance in in vitro UCL and in vivo CT imaging. On the basis of our findings, the as-obtained functionalized UCNPs could be considered as a promising versatile dual-mode imaging probe for bioimaging, tumor diagnosis, and cancer therapy.
关键词： red luminescence enhancement,Lu3+ doping,upconversion nanoparticles,multimodal imaging,CT contrast
更新于2025-11-14 17:04:02
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Zero contrast optical coherence tomography–guided percutaneous coronary intervention for in-stent restenosis of the saphenous vein graft using a non-contrast flush medium
摘要： Percutaneous coronary intervention (PCI) is often denied for individuals with coronary artery disease who are prone to develop contrast-induced acute kidney injury. We report a 73-year-old, stage 3 chronic kidney disease patient (CKD), who underwent coronary artery bypass surgery and saphenous vein graft (SVG) stenting in the past, presented with in-stent restenosis (ISR) of SVG stent. Zero contrast optical coherence tomography (OCT) guidedePCI was successfully performed using low molecular weight dextran-40 (LMWD-40) as the ?ush medium. Our report suggests the safety and feasibility of LMWD-40 ebased OCT-guided zero contrast PCI in ISR of SVG in a CKD patient, although further prospective studies are needed to evaluate this technique.
关键词： Zero contrast,Chronic kidney disease,Dextran-40,Contrast induced-Acute kidney injury,Percutaneous coronary intervention,Optical coherence tomography
更新于2025-09-23 15:23:52
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Multichannel image contrast enhancement based on linguistic rule-based intensificators
摘要： This study follows the direct approach to image contrast enhancement, which changes the image contrast at each its pixel and is more effective than the indirect approach that deals with image histograms. However, there are only few studies following the direct approach because, by its nature, it is very complex. Additionally, it is difficult to develop an effective method since it is required to keep a balance in maintaining local and global image features while changing the contrast at each individual pixel. Moreover, raw images obtained from many sources randomly influenced by many external factors can be considered as fuzzy uncertain data. In this context, we propose a novel method to apply and immediately handle expert fuzzy linguistic knowledge of image contrast enhancement to simulate human capability in using natural language. The formalism developed in the study is based on hedge algebras considered as a theory, which can immediately handle linguistic words of variables. This allows the proposed method to produce an image contrast intensificator from a given expert linguistic rule base. A technique to preserve global as well as local image features is proposed based on a fuzzy clustering method, which is applied for the first time in this field to reveal region image features of raw images. The projections of the obtained clusters on each channel are suitably aggregated to produce a new channel image considered as input of the pixelwise defined operators proposed in this study. Many experiments are performed to demonstrate the effect of the proposed method versus the counterparts considered.
关键词： interpolation inference method,contrast measurement,image contrast enhancement,hedge algebra,linguistic rule-based knowledge
更新于2025-09-23 15:23:52
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System Design and Evaluation of a Compact and High Energy X-ray Talbot-Lau Grating Interferometer for Industrial Applications
摘要： X-ray grating interferometry has been an active area of research in recent years. In particular, various studies have been carried out for the practical use of the x-ray grating interferometer in medical and industrial fields. For the commercialization of the system, it needs to be optimized for its application. In this study, we have developed a prototype of the compact high energy x-ray grating interferometer of which the high effective energy and compactness is of our primary feature of design. We have designed the Talbot-Lau x-ray interferometer in a symmetrical geometry with an effective energy of 54.3 keV. The system has a source-to-analyzer grating distance of 788.4 mm, which is compact enough for a commercial product. In a normal operation, it took less than ten seconds to acquire a set of phase stepping images. The acquired images had a maximum visibility of about 15%, which is relatively high compared with the visibilities of the other high-energy grating interferometric systems reported so far.
关键词： X-ray phase contrast imaging,Dark-field imaging,Talbot-Lau interferometry,compact design,High energy phase contrast imaging
更新于2025-09-23 15:23:52
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Scatter Enhanced Phase Contrast Microscopy for Discriminating Mechanisms of Active Nanoparticle Transport in Living Cells
摘要： Understanding the uptake and transport dynamics of engineered nanomaterials (ENMs) by mammalian cells is an important step in designing next-generation drug delivery systems. However, to track these materials and their cellular interactions, current studies often depend on surface-bound fluorescent labels which have the potential to alter native cellular recognition events. As a result, there is still a need to develop methods capable of monitoring ENM-cell interactions independent of surface modification. Addressing these concerns, here we show how Scatter Enhanced Phase Contrast (SEPC) microscopy can be extended to work as a generalized label-free approach for monitoring nanoparticle uptake and transport dynamics. To determine which materials can be studied using SEPC, we turn to Lorenz-Mie theory, predicting that individual particles down to ~35 nm can be observed. We confirm this experimentally, demonstrating that SEPC works for a variety of metal and metal oxides, including: Au, Ag, TiO2, CeO2, Al2O3, and Fe2O3 nanoparticles. We then demonstrate that SEPC microscopy can be used in a quantitative, time-dependent fashion to discriminate between distinct modes of active cellular transport, including intracellular transport and membrane assisted transport. Finally, we combine this technique with microcontact printing to normalize transport dynamics across multiple cells, allowing for a careful study of ensemble TiO2 nanoparticle uptake. This revealed three distinct regions of particle transport across the cell, indicating that membrane dynamics play an important role in regulating particle flow. By avoiding fluorescent labels, SEPC allows for a rational exploration of the surface properties of nanomaterials in their native state and their role in endocytosis and cellular transport.
关键词： Scatter Enhanced Phase Contrast,Lorenz-Mie Theory,Endocytosis,Nano-Bio Interface,Nanoparticle
更新于2025-09-23 15:23:52
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Objective Quality Assessment of Image Enhancement Methods in Digital Mammography - A Comparative Study
摘要： Mammography is the primary and most reliable technique for detection of breast cancer. Mammograms are examined for the presence of malignant masses and indirect signs of malignancy such as micro calcifications, architectural distortion and bilateral asymmetry. However, Mammograms are X-ray images taken with low radiation dosage which results in low contrast, noisy images. Also, malignancies in dense breast are difficult to detect due to opaque uniform background in mammograms. Hence, techniques for improving visual screening of mammograms are essential. Image enhancement techniques are used to improve the visual quality of the images. This paper presents the comparative study of different pre-processing techniques used for enhancement of mammograms in mini-MIAS data base. Performance of the image enhancement techniques is evaluated using objective image quality assessment techniques. They include simple statistical error metrics like PSNR and human visual system (HVS) feature based metrics such as SSIM, NCC, UIQI, and Discrete Entropy
关键词： Adaptive median filter,HE,Contrast stretching,Wavelet transforms,CLAHE
更新于2025-09-23 15:23:52
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Real time video image enhancement approach using particle swarm optimisation technique with adaptive cumulative distribution function based histogram equalization
摘要： Recent years, real time videos are playing an important role in different applications such as pattern recognition, security purpose, news analysis, weather digest, and video browser and so on. Due to the importance of real time video applications, the quality of the real time video must be improved for making effective results in real time video analysis process. This paper introduces the particle optimization with adaptive cumulative distribution based histogram enhancement technique (PACDHE) for improving the real time video quality. Initially the videos are collected, each incoming frame has been analyzed and noise present in the video frame is eliminated by applying the non-divisional median filter. After that, quality of real time video is enhanced iteratively by examining each pixel present in video frames using the optimized fitness and cumulative distribution function. This process is repeated continuously until to enhance the real time video frames contrast and quality. Then the performance of the system is analyzed by using CV online video database and the efficiency is examined in terms of peak signal to noise ratio (PSNR), Absolute Mean Brightness Error (AMBE) and Entropy. The experimental results of PSO are compared with genetic algorithm based approach and found that PSO outperforms the GA approach and the existing histogram equalization approach and the existing histogram equalization approaches.
关键词： contrast enhancement,particle optimization based adaptive cumulative distribution based histogram enhancement technique (PACDHE),fitness and cumulative distribution function,CV online video database,Video quality
更新于2025-09-23 15:23:52
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Investigation of inner ear anatomy in mouse using X-ray phase contrast tomography
摘要： A thorough understanding of inner ear anatomy is important for investigators. However, investigation of the mouse inner ear is difficult due to the limitations of imaging techniques. X-ray phase contrast tomography increases contrast 100–1,000 times compared with conventional X-ray imaging. This study aimed to investigate inner ear anatomy in a fresh post-mortem mouse using X-ray phase contrast tomography and to provide a comprehensive atlas of microstructures with less tissue deformation. All experiments were performed in accordance with our institution's guidelines on the care and use of laboratory animals. A fresh mouse cadaver was scanned immediately after sacrifice using an inline phase contrast tomography system. Slice images were reconstructed using a filtered back-projection (FBP) algorithm. Standardized axial and coronal planes were adjusted with a multi-planar reconstruction method. Some three-dimensional (3D) objects were reconstructed by surface rendering. The characteristic features of microstructures, including otoconia masses of the saccular and utricular maculae, superior and inferior macula cribrosae, single canal, modiolus, and osseous spiral lamina, were described in detail. Spatial positions and relationships of the vestibular structures were exhibited in 3D views. This study investigated mouse inner ear anatomy and provided a standardized presentation of microstructures. In particular, otoconia masses were visualized in their natural status without contrast for the first time. The comprehensive anatomy atlas presented in this study provides an excellent reference for morphology studies of the inner ear.
关键词： saccular macula,phase contrast imaging,inner ear,utricular macula,otoconia
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow, Poland (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - A novel method to explore intrarenal arterial tree using micro-CT
摘要： The minimally invasive approach for renal surgeries, among others, requires preoperative determination of intrarenal arteries. Their proper identification based on standard preoperative CT images is still not a fully solved problem. Therefore, we decided to resolve this issue by providing a tree topology model using post-mortem kidneys. The number of vessels that compose intrarenal tree is so large, that it cannot by analyzed manually without the aid of image processing techniques. So that, the vessels has to be first depicted using an imaging technique that enables to provide superior resolution in comparison to standard CT scan. In this paper, we present a research on various injection materials enabling to fill the vascular beds in order to scan them using micro-CT and further reconstruct as a 3D model. The evaluated materials were chosen so that they are widely available and affordable. We compare them in terms of their ability to absorb ionizing radiation and penetrate vascular beds (density, viscosity), homogeneity, solidification rate, resistance to solvents and durability. We also present the technique of injecting kidney arteries with the use of the selected material - two-part epoxy adhesive with 10% iodine. In contrast to standard corrosive endocast preparation, in our case there is no need to remove soft parenchymal tissue which takes about two weeks using corrosive materials such as strong acids and bases. The proposed filling material enables to enhance vascular tree to such extend that micro-CT scans of the whole kidneys can be performed. This enables instantaneous substance injection and imaging without permanently destroying the soft tissue material. This approach can be used in various scenarios in which a filling material with the ability to increase radiation absorption is required and there is a need to maintain the integrity of the structure. To the best of our knowledge, this is the first such attempt. The obtained vascular trees by the means of micro-CT confirm the validity of the presented approach.
关键词： cast,micro-CT,3D vascular tree,minimally invasive surgery,contrast agents,ability to absorb ionizing radiation,kidney surgery,injection materials,kidney
更新于2025-09-23 15:23:52