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In vivo evaluation of a lipopolysaccharide-induced ear vascular leakage model in mice using photoacoustic microscopy

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BIOMEDICAL OPTICS EXPRESS 2022年第9期13卷 4802-4816页

作者： LI, Zhe He, Pengbo Xu, Yuqing Deng, Yuxiao Gao, Yuvan Chen, Sung -liang Shanghai Jiao Tong Univ Renji Hosp Sch Med Dept Crit Care Med Shanghai 200127 Peoples R China Shanghai Jiao Tong Univ Univ Michigan Shanghai Jiao Tong Univ Joint Inst Shanghai 200240 Peoples R China Minist Educ Engn Res Ctr Digital Med & Clin Translat Shanghai 200030 Peoples R China Shanghai Jiao Tong Univ State Key Lab Adv Opt Commun Syst & Networks Shanghai 200240 Peoples R China

Sepsis is caused by dysregulated host inflammatory response to infection. During sepsis, early identification and monitoring of vascular leakage are pivotal for improved diagnosis, treatment, and prognosis. However, there is a lack of research on noninvasive observation of inflammation-related vascular leakage. Here, we investigate the use of photoacoustic microscopy (PAM) for in vivo visualization of lipopolysaccharide (LPS)-induced ear vascular leakage in mice using Evans blue (EB) as an indicator. A model combining needle pricking on the mouse ear, topical smearing of LPS on the mouse ear, and intravenous tail injection of EB is developed. Topical application of LPS is expected to induce local vascular leakage in skin. Inflammatory response is first validated by ex vivo histology and enzyme-linked immunosorbent assay. Then, local ear vascular leakage is confirmed by ex vivo measurement of swelling, thickening, and EB leakage. Finally, PAM for in vivo identification and evaluation of early vascular leakage using the model is demonstrated. For PAM, common excitation wavelength of 532 nm is used, and an algorithm is developed to extract quantitative metrics for EB leakage. The results show potential of PAM for noninvasive longitudinal monitoring of peripheral skin vascular leakage, which holds promise for clinical sepsis diagnosis and management.(c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Functional imaging image processing image processing algorithms Imaging techniques Medical imaging Microscopy

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Toward a super imaging system [Invited]

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APPLIED OPTICS 2013年第4期52卷 561-566页

作者： Mendlovic, David Tel Aviv Univ Fac Engn IL-69978 Tel Aviv Israel

This paper deals with the fast-developing area of computational photography where a combination of imaging techniques and efficient image processing algorithms is done to generate a super imaging system. In recent years, three main implementations of the computational photography philosophy were intensively investigated and demonstrated: (i) multiple aperture, (ii) light field photography, and (iii) multiexposure. The paper provides a mini-review of these three approaches and shows ways to improve and combine them toward a super imaging system. As a conclusion, the paper provides preliminary guidelines for fusing the three approaches into one integrated super imaging system with optimized performance. (C) 2013 Optical Society of America

关键词： image processing image processing algorithms image quality Imaging systems Imaging techniques Optical imaging

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Speckle reduction using an artificial neural network algorithm

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APPLIED OPTICS 2013年第21期52卷 5050-5057页

作者： Avanaki, Mohammad R. N. Laissue, P. Philippe Eom, Tae Joong Podoleanu, Adrian G. Hojjatoleslami, Ali Univ Kent Kent Inst Med & Hlth Sci Ctr Res & Dev Canterbury CT2 7PD Kent England Gwangju Inst Sci & Technol Adv Photon Res Inst Kwangju South Korea Univ Kent Sch Phys Sci Appl Opt Grp Canterbury CT2 7NH Kent England

This paper presents an algorithm for reducing speckle noise from optical coherence tomography (OCT) images using an artificial neural network (ANN) algorithm. The noise is modeled using Rayleigh distribution with a noise parameter, sigma, estimated by the ANN. The input to the ANN is a set of intensity and wavelet features computed from the image to be processed, and the output is an estimated sigma value. This is then used along with a numerical method to solve the inverse Rayleigh function to reduce the noise in the image. The algorithm is tested successfully on OCT images of Drosophila larvae. It is demonstrated that the signal-to-noise ratio and the contrast-to-noise ratio of the processed images are increased by the application of the ANN algorithm in comparison with the respective values of the original images. (C) 2013 Optical Society of America

关键词： Anisotropic diffusion image metrics image processing image processing algorithms Speckle noise Speckle reduction

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Optimization of a flexible fiber-optic probe for epi-mode quantitative phase imaging

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OPTICS EXPRESS 2022年第11期30卷 17713-17729页

作者： Guang, Zhe Ledwig, Patrick Costa, Paloma Casteleiro Filan, Caroline Robles, Francisco E. Georgia Inst Technol & Emory Univ Wallace H Coulter Dept Biomed Engn Atlanta GA 30332 USA Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA Georgia Inst Technol George W Woodruff Sch Mech Engn Atlanta GA 30332 USA Emory Univ Winshtp Canc Inst Atlanta GA 30322 USA

Quantitative oblique back-illumination microscopy (qOBM) is an emerging label-free optical imaging technology that enables 3D, tomographic quantitative phase imaging (QPI) with epi-illumination in thick scattering samples. In this work, we present a robust optimization of a flexible, fiber-optic-based qOBM system. Our approach enables in silico optimization of the phase signal-to-noise-ratio over a wide parameter space and obviates the need for tedious experimental optimization which could easily miss optimal conditions. Experimental validations of the simulations are also presented and sensitivity limits for the probe are assessed. The optimized probe is light-weight (similar to 40g) and compact (8mm in diameter) and achieves a 2 mu m lateral resolution, 6 mu m axial resolution, and a 300 mu m field of view, with near video-rate operation (10Hz, limited by the camera). The phase sensitivity is <20nm for a single qOBM acquisition (at 10Hz) and a lower limit of similar to 3 nm via multi-frame averaging. Finally, to demonstrate the utility of the optimized probe, we image (1) thick, fixed rat brain samples from a 9L gliosarcoma tumor model and (2) freshly excised human brain tissues from neurosurgery. Acquired qOBM images using the flexible fiber-optic probe are in excellent agreement with those from a free-space qOBM system (both in-situ), as well as with gold-standard histopathology slices (after tissue processing). (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： image processing algorithms Imaging techniques Optical imaging Phase contrast Phase imaging Point spread function

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Accuracy of the reconstruction of the crystalline lens gradient index with optimization methods from Ray Tracing and Optical Coherence Tomography data

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OPTICS EXPRESS 2011年第20期19卷 19265-19279页

作者： de Castro, Alberto Barbero, Sergio Ortiz, Sergio Marcos, Susana CSIC Inst Opt Daza de Valdes Madrid 28006 Spain

The accuracy of the reconstruction of the Gradient Refractive Index (GRIN) of the crystalline lens from optimization methods was evaluated. Different input data, including direction cosines of deflected rays, ray impacts obtained from ray tracing and optical path differences from Optical Coherence Tomography (OCT) were studied. Three different GRIN models were analyzed. The experimental errors of the different experimental input data were estimated from comparisons of measurements and simulations using artificial lenses of known geometries. The experimental errors in the surfaces shape measurement and the influence of the number of rays were also considered. OCT-based input data produced the most accurate GRIN reconstructions. We found that optimization methods (combining global and local search algorithms) allow GRIN reconstructions with acceptable accuracies for moderate noise level. (C) 2011 Optical Society of America

关键词： Crystalline lens Fiber optic sensors image processing algorithms Magnetic resonance imaging Ray tracing Refractive index

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Ultra-fast, universal super-resolution radial fluctuations (SRRF) algorithm for live-cell super-resolution microscopy

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OPTICS EXPRESS 2019年第26期27卷 38337-38348页

作者： Han, Yubing Lu, Xiao Zhang, Zhimin Liu, Wenjie Chen, Yuchen Liu, Xu Hao, Xiang Kuang, Cuifang Zhejiang Univ State Key Lab Modern Opt Instrumentat Coll Opt Sci & Engn Hangzhou 310027 Zhejiang Peoples R China Shanxi Univ Collaborat Innovat Ctr Extreme Opt Taiyuan 030006 Shanxi Peoples R China Zhejiang Univ Ningbo Res Inst Ningbo 315100 Peoples R China

For a long term, spatial resolution of fluorescence microscopy was strictly restricted by the diffraction limit. To solve this problem, various super-resolution technologies have been developed. Super-resolution radial fluctuations (SRRF), an emerging type of super-resolution microscopy, directly analyze raw images and generate super-resolution results without fluorophore localization, thereby showing more advantages in handling high-density data. Here, by speeding up the process of the algorithm with graphics processing unit (GPU) and programming with Python language, we expand the universality and improve the computing speed of the SRRF algorithm. We further apply our SRRF algorithm in different live-cell super-resolution microscopy methods with two types of fluorescence fluctuation sources: (i) direct stochastic optical reconstruction microscopy (dSTORM) in which fluorophores themselves blink under specific buffer and laser condition and (ii) structural illumination microscopy (SIM) and modulated Airyscan in which fluorescence fluctuations are artificially introduced with modulated laser illumination. With improved spatiotemporal resolution and image quality, our SRRF algorithm demonstrates its capability in live-cell super-resolution imaging, indicating its wide applications in life sciences. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Diffraction limit Green fluorescent protein image processing algorithms image quality Speckle patterns Total internal reflection

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Correction method for stripe nonuniformity

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APPLIED OPTICS 2010年第10期49卷 1764-1773页

作者： Qian, Weixian Chen, Qian Gu, Guohua Guan, Zhiqiang Nanjing Univ Sci & Technol Lab 440 Nanjing Peoples R China

Stripe nonuniformity is very typical in line infrared focal plane arrays (IR-FPA) and uncooled staring IR-FPA. In this paper, the mechanism of the stripe nonuniformity is analyzed, and the gray-scale co-occurrence matrix theory and optimization theory are studied. Through these efforts, the stripe nonuniformity correction problem is translated into the optimization problem. The goal of the optimization is to find the minimal energy of the image's line gradient. After solving the constrained non-linear optimization equation, the parameters of the stripe nonuniformity correction are obtained and the stripe nonuniformity correction is achieved. The experiments indicate that this algorithm is effective and efficient. (C) 2010 Optical Society of America

关键词： algorithms Discrete Fourier transforms image processing image processing algorithms Power spectra Real time implementation

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Target detection with a liquid-crystal-based passive Stokes polarimeter

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APPLIED OPTICS 2004年第2期43卷 274-282页

作者： Goudail, F Terrier, P Takakura, Y Bigué, L Galland, F DeVlaminck, V Fresnel Inst CNRS UMR 6133 Marseille France Lab Interact Image & Ingn Decis CNRS FRE 2497 Lille France Lab Sci Image Informat & Teledetect CNRS UMR 7005 Strasbourg France Lab Modelisat Intelligence Proc & Syst Mulhouse France

We present an imaging system that measures the polarimetric state of the light coming from each point of a scene. This system, which determines the four components of the Stokes vector at each spatial location, is based on a liquid-crystal polarization modulator, which makes it possible to acquire four-dimensional Stokes parameter images at a standard video rate. We show that using such polarimetric images instead of simple intensity images can improve target detection and segmentation performance. (C) 2004 Optical Society of America.

关键词： image processing image processing algorithms image quality Imaging systems Liquid crystal modulators Polarimetric imaging

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Diffusion dynamics of small molecules from mesoporous silicon films by real-time optical interferometry

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APPLIED OPTICS 2011年第27期50卷 5329-5337页

作者： Mares, Jeremy W. Weiss, Sharon M. Vanderbilt Univ Dept Elect Engn & Comp Sci Nashville TN 37235 USA

Time-dependent laser reflectometry measurements are presented as a means to rigorously characterize analyte diffusion dynamics of small molecules from mesoporous silicon (PSi) films for drug delivery and membrane physics applications. Calculations based on inclusion of a spatially and temporally dependent solute concentration profile in a one-dimensional Fickian diffusion flow model are performed to determine the diffusion coefficients for the selected prototypical polar species, sucrose (340 Da), exiting from PSi films. The diffusion properties of the molecules depend on both PSi pore size and film thickness. For films with average pore diameters between 10-30 nm and film thicknesses between 300-900 nm, the sucrose diffusion coefficient can be tuned between approximately 100 and 550 mu m(2)/s. Extensions of the real-time measurement and modeling approach for determining the diffusivity of small molecules that strongly interact with and corrode the internal surfaces of PSi films are also discussed. (C) 2011 Optical Society of America

关键词： Beam scattering Diffusion Effective refractive index image processing algorithms Laser interferometry Scanning electron microscopy

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Differential interference contrast microscope using photonic crystals for phase imaging and three-dimensional shape reconstruction

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APPLIED OPTICS 2009年第7期48卷 1347-1357页

作者： Fabre, Laurent Inoue, Yoshihiko Aoki, Takafumi Kawakami, Shojiro Tohoku Univ Grad Sch Informat Sci Aoba Ku Sendai Miyagi 9808579 Japan Sendai Fdn Appl Informat Sci Aoba Ku Sendai Miyagi 9800845 Japan Photon Lattice Inc Aoba Incubat Sq Aoba Ku Sendai Miyagi 9800845 Japan

We present a differential interference contrast microscope using photonic crystals capable of real-time capture of both phase and amplitude components independently without moving parts. Unlike previous methods using rotating polarizers to discriminate each component, we propose using a special camera equipped with an arrayed polarizer whose instant polarization measurement allows real-time acquisition of the phase gradient information. A two-image algorithm is used to reconstruct the phase two-dimensional distribution of biological samples from the gradient information with a transmission-type microscope. We also talk about deducing a sample's three-dimensional shape for a reflection-type microscope. The efficiency of the method is demonstrated experimentally. (C) 2009 Optical Society of America

关键词： image processing algorithms image registration Interference microscopy Phase measurement Polarimetric imaging Three dimensional imaging

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