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Sample records for promising imaging method

  1. Nanostructures based on quantum dots for application in promising methods of single- and multiphoton imaging and diagnostics

    Science.gov (United States)

    Nabiev, I. R.

    2017-01-01

    Molecules recognizing biomarkers of diseases (monoclonal antibodies (monoABs)) are often too large for biomedical applications, and the conditions that are used to bind them with nanolabels lead to disordered orientation of monoABs with respect to the nanoparticle surface. Extremely small nanoprobes, designed via oriented conjugation of quantum dots (QDs) with single-domain antibodies (sdABs) derived from the immunoglobulin of llama and produced in the E. coli culture, have a hydrodynamic diameter less than 12 nm and contain equally oriented sdAB molecules on the surface of each QD. These nanoprobes exhibit excellent specificity and sensitivity in quantitative determination of a small number of cells expressing biomarkers. In addition, the higher diffusion coefficient of sdABs makes it possible to perform immunohistochemical analysis in bulk tissue, inaccessible for conventional monoABs. The necessary conditions for implementing high-quality immunofluorescence diagnostics are a high specificity of labeling and clear differences between the fluorescence of nanoprobes and the autofluorescence of tissues. Multiphoton micros-copy with excitation in the near-IR spectral range, which is remote from the range of tissue autofluorescence excitation, makes it possible to solve this problem and image deep layers in biological tissues. The two-photon absorption cross sections of CdSe/ZnS QDs conjugated with sdABs exceed the corresponding values for organic fluorophores by several orders of magnitude. These nanoprobes provide clear discrimination between the regions of tumor and normal tissues with a ratio of the sdAB fluorescence to the tissue autofluorescence upon two-photon excitation exceeding that in the case of single-photon excitation by a factor of more than 40. The data obtained indicate that the sdAB-QD conjugates used as labels provide the same, or even better, quality as the "gold standard" of immunohistochemical diagnostics. The developed nanoprobes are expected to

  2. [Rapid prototyping: a very promising method].

    Science.gov (United States)

    Haverman, T M; Karagozoglu, K H; Prins, H-J; Schulten, E A J M; Forouzanfar, T

    2013-03-01

    Rapid prototyping is a method which makes it possible to produce a three-dimensional model based on two-dimensional imaging. Various rapid prototyping methods are available for modelling, such as stereolithography, selective laser sintering, direct laser metal sintering, two-photon polymerization, laminated object manufacturing, three-dimensional printing, three-dimensional plotting, polyjet inkjet technology,fused deposition modelling, vacuum casting and milling. The various methods currently being used in the biomedical sector differ in production, materials and properties of the three-dimensional model which is produced. Rapid prototyping is mainly usedforpreoperative planning, simulation, education, and research into and development of bioengineering possibilities.

  3. Nanomedicine: Perspective and promises with ligand-directed molecular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pan Dipanjan [Department of Medicine, Washington University Medical School, St. Louis, MO (United States)], E-mail: dipanjan@wustl.edu; Lanza, Gregory M.; Wickline, Samuel A. [Department of Medicine, Washington University Medical School, St. Louis, MO (United States); Caruthers, Shelton D. [Department of Medicine, Washington University Medical School, St. Louis, MO (United States); Philips Healthcare, Andover, MA (United States)], E-mail: scaruthers@cmrl.wustl.edu

    2009-05-15

    Molecular imaging and targeted drug delivery play an important role toward personalized medicine, which is the future of patient management. Of late, nanoparticle-based molecular imaging has emerged as an interdisciplinary area, which shows promises to understand the components, processes, dynamics and therapies of a disease at a molecular level. The unprecedented potential of nanoplatforms for early detection, diagnosis and personalized treatment of diseases, have found application in every biomedical imaging modality. Biological and biophysical barriers are overcome by the integration of targeting ligands, imaging agents and therapeutics into the nanoplatform which allow for theranostic applications. In this article, we have discussed the opportunities and potential of targeted molecular imaging with various modalities putting a particular emphasis on perfluorocarbon nanoemulsion-based platform technology.

  4. Nanomedicine: Perspective and promises with ligand-directed molecular imaging

    International Nuclear Information System (INIS)

    Pan Dipanjan; Lanza, Gregory M.; Wickline, Samuel A.; Caruthers, Shelton D.

    2009-01-01

    Molecular imaging and targeted drug delivery play an important role toward personalized medicine, which is the future of patient management. Of late, nanoparticle-based molecular imaging has emerged as an interdisciplinary area, which shows promises to understand the components, processes, dynamics and therapies of a disease at a molecular level. The unprecedented potential of nanoplatforms for early detection, diagnosis and personalized treatment of diseases, have found application in every biomedical imaging modality. Biological and biophysical barriers are overcome by the integration of targeting ligands, imaging agents and therapeutics into the nanoplatform which allow for theranostic applications. In this article, we have discussed the opportunities and potential of targeted molecular imaging with various modalities putting a particular emphasis on perfluorocarbon nanoemulsion-based platform technology.

  5. Image is more than a uniform: the promise of assurance.

    Science.gov (United States)

    Wocial, Lucia D; Sego, Kelly; Rager, Carrie; Laubersheimer, Shellee; Everett, Linda Q

    2014-05-01

    The purpose of this qualitative study was to explore the meaning of the phrase "image of the nurse" in the context of the desired brand experience of assurance. A brand is a promise that lives in the minds of consumers. Nurses play a key role in delivering on the brand promise of a hospital. Using focus groups, the authors applied a deductive approach to generate data. Discussion transcripts were analyzed by establishing codes and identifying themes. The most frequent comment from participants was that for nurses to communicate assurance, they must 1st be clean, well groomed, and understated in overall appearance. Nurse behaviors that reassure patients include being present with patients, helping patients know what to expect, and demonstrating a consistent team approach. Overall appearance and behaviors define the image of nurses and contribute significantly to the brand of assurance.

  6. Visualizing Chemistry: The Progess and Promise of Advanced Chemical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Committee on Revealing Chemistry Through Advanced Chemical Imaging

    2006-09-01

    The field of chemical imaging can provide detailed structural, functional, and applicable information about chemistry and chemical engineering phenomena that have enormous impacts on medicine, materials, and technology. In recognizing the potential for more research development in the field of chemical imaging, the National Academies was asked by the National Science Foundation, Department of Energy, U.S. Army, and National Cancer Institute to complete a study that would review the current state of molecular imaging technology, point to promising future developments and their applications, and suggest a research and educational agenda to enable breakthrough improvements in the ability to image molecular processes simultaneously in multiple physical dimensions as well as time. The study resulted in a consensus report that provides guidance for a focused research and development program in chemical imaging and identifies research needs and possible applications of imaging technologies that can provide the breakthrough knowledge in chemistry, materials science, biology, and engineering for which we should strive. Public release of this report is expected in early October.

  7. PROMISE: parallel-imaging and compressed-sensing reconstruction of multicontrast imaging using SharablE information.

    Science.gov (United States)

    Gong, Enhao; Huang, Feng; Ying, Kui; Wu, Wenchuan; Wang, Shi; Yuan, Chun

    2015-02-01

    A typical clinical MR examination includes multiple scans to acquire images with different contrasts for complementary diagnostic information. The multicontrast scheme requires long scanning time. The combination of partially parallel imaging and compressed sensing (CS-PPI) has been used to reconstruct accelerated scans. However, there are several unsolved problems in existing methods. The target of this work is to improve existing CS-PPI methods for multicontrast imaging, especially for two-dimensional imaging. If the same field of view is scanned in multicontrast imaging, there is significant amount of sharable information. It is proposed in this study to use manifold sharable information among multicontrast images to enhance CS-PPI in a sequential way. Coil sensitivity information and structure based adaptive regularization, which were extracted from previously reconstructed images, were applied to enhance the following reconstructions. The proposed method is called Parallel-imaging and compressed-sensing Reconstruction Of Multicontrast Imaging using SharablE information (PROMISE). Using L1 -SPIRiT as a CS-PPI example, results on multicontrast brain and carotid scans demonstrated that lower error level and better detail preservation can be achieved by exploiting manifold sharable information. Besides, the privilege of PROMISE still exists while there is interscan motion. Using the sharable information among multicontrast images can enhance CS-PPI with tolerance to motions. © 2014 Wiley Periodicals, Inc.

  8. Compton scatter imaging: A promising modality for image guidance in lung stereotactic body radiation therapy.

    Science.gov (United States)

    Redler, Gage; Jones, Kevin C; Templeton, Alistair; Bernard, Damian; Turian, Julius; Chu, James C H

    2018-03-01

    Lung stereotactic body radiation therapy (SBRT) requires delivering large radiation doses with millimeter accuracy, making image guidance essential. An approach to forming images of patient anatomy from Compton-scattered photons during lung SBRT is presented. To investigate the potential of scatter imaging, a pinhole collimator and flat-panel detector are used for spatial localization and detection of photons scattered during external beam therapy using lung SBRT treatment conditions (6 MV FFF beam). MCNP Monte Carlo software is used to develop a model to simulate scatter images. This model is validated by comparing experimental and simulated phantom images. Patient scatter images are then simulated from 4DCT data. Experimental lung tumor phantom images have sufficient contrast-to-noise to visualize the tumor with as few as 10 MU (0.5 s temporal resolution). The relative signal intensity from objects of different composition as well as lung tumor contrast for simulated phantom images agree quantitatively with experimental images, thus validating the Monte Carlo model. Scatter images are shown to display high contrast between different materials (lung, water, bone). Simulated patient images show superior (~double) tumor contrast compared to MV transmission images. Compton scatter imaging is a promising modality for directly imaging patient anatomy during treatment without additional radiation, and it has the potential to complement existing technologies and aid tumor tracking and lung SBRT image guidance. © 2018 American Association of Physicists in Medicine.

  9. Universal Image Steganalytic Method

    Directory of Open Access Journals (Sweden)

    V. Banoci

    2014-12-01

    Full Text Available In the paper we introduce a new universal steganalytic method in JPEG file format that is detecting well-known and also newly developed steganographic methods. The steganalytic model is trained by MHF-DZ steganographic algorithm previously designed by the same authors. The calibration technique with the Feature Based Steganalysis (FBS was employed in order to identify statistical changes caused by embedding a secret data into original image. The steganalyzer concept utilizes Support Vector Machine (SVM classification for training a model that is later used by the same steganalyzer in order to identify between a clean (cover and steganographic image. The aim of the paper was to analyze the variety in accuracy of detection results (ACR while detecting testing steganographic algorithms as F5, Outguess, Model Based Steganography without deblocking, JP Hide and Seek which represent the generally used steganographic tools. The comparison of four feature vectors with different lengths FBS (22, FBS (66 FBS(274 and FBS(285 shows promising results of proposed universal steganalytic method comparing to binary methods.

  10. Three-dimensional imaging technology offers promise in medicine.

    Science.gov (United States)

    Karako, Kenji; Wu, Qiong; Gao, Jianjun

    2014-04-01

    Medical imaging plays an increasingly important role in the diagnosis and treatment of disease. Currently, medical equipment mainly has two-dimensional (2D) imaging systems. Although this conventional imaging largely satisfies clinical requirements, it cannot depict pathologic changes in 3 dimensions. The development of three-dimensional (3D) imaging technology has encouraged advances in medical imaging. Three-dimensional imaging technology offers doctors much more information on a pathology than 2D imaging, thus significantly improving diagnostic capability and the quality of treatment. Moreover, the combination of 3D imaging with augmented reality significantly improves surgical navigation process. The advantages of 3D imaging technology have made it an important component of technological progress in the field of medical imaging.

  11. Clinical PET/CT imaging. Promises and misconceptions

    International Nuclear Information System (INIS)

    Czernin, J.; Auerbach, M.A.

    2005-01-01

    PET/CT is now established as the most important imaging tool in oncology. PET/CT stages and restages cancer with a higher accuracy than PET or CT alone. The sometimes irrational approach to combine state of the art PET with the highest end CT devices should give way to a more reasonable equipment design tailored towards the specific clinical indications in well-defined patient populations. The continuing success of molecular PET/CT now depends more upon advances in molecular imaging with the introduction of targeted imaging probes for individualized therapy approaches in cancer patients and less upon technological advances of imaging equipment. (orig.)

  12. Molecular Imaging: A Promising Tool to Monitor Islet Transplantation

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2011-01-01

    Full Text Available Replacement of insulin production by pancreatic islet transplantation has great potential as a therapy for type 1 diabetes mellitus. At present, the lack of an effective approach to islet grafts assessment limits the success of this treatment. The development of molecular imaging techniques has the potential to fulfill the goal of real-time noninvasive monitoring of the functional status and viability of the islet grafts. We review the application of a variety of imaging modalities for detecting endogenous and transplanted beta-cell mass. The review also explores the various molecular imaging strategies for assessing islet delivery, the metabolic effects on the islet grafts as well as detection of immunorejection. Here, we highlight the use of combined imaging and therapeutic interventions in islet transplantation and the in vivo monitoring of stem cells differentiation into insulin-producing cells.

  13. Quantifying Neonatal Sucking Performance: Promise of New Methods.

    Science.gov (United States)

    Capilouto, Gilson J; Cunningham, Tommy J; Mullineaux, David R; Tamilia, Eleonora; Papadelis, Christos; Giannone, Peter J

    2017-04-01

    Neonatal feeding has been traditionally understudied so guidelines and evidence-based support for common feeding practices are limited. A major contributing factor to the paucity of evidence-based practice in this area has been the lack of simple-to-use, low-cost tools for monitoring sucking performance. We describe new methods for quantifying neonatal sucking performance that hold significant clinical and research promise. We present early results from an ongoing study investigating neonatal sucking as a marker of risk for adverse neurodevelopmental outcomes. We include quantitative measures of sucking performance to better understand how movement variability evolves during skill acquisition. Results showed the coefficient of variation of suck duration was significantly different between preterm neonates at high risk for developmental concerns (HRPT) and preterm neonates at low risk for developmental concerns (LRPT). For HRPT, results indicated the coefficient of variation of suck smoothness increased from initial feeding to discharge and remained significantly greater than healthy full-term newborns (FT) at discharge. There was no significant difference in our measures between FT and LRPT at discharge. Our findings highlight the need to include neonatal sucking assessment as part of routine clinical care in order to capture the relative risk of adverse neurodevelopmental outcomes at discharge. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. Advertising and drugs: a world of images and promises

    Directory of Open Access Journals (Sweden)

    Jurema Barros Dantas

    2010-11-01

    Full Text Available The aim of this article is to discuss the relation between the contemporary use and advertising of pharmaceutical drugs based on the so-called culture of consumption. We discuss advertising as a means of strengthening the belief in the power of these drugs, presenting them as a synthesis of science and technology to promote health and well being and, particularly, as a quick solution for typical problems of the contemporary world. The obligation to buy the latest medicines is becoming a symbol of social affirmation as well as the only way to weaken our daily problems. Using a logic of consumption as ownership, we create, with the help of advertising, a world of promises concerning immediate solutions, easily sold through on line shopping, supermarkets, department stores and shopping centers. We discuss this set of contemporary practices and values which are turning our way of life into a disposable product.   Keywords: advertising; consumption; pharmaceutical drugs.

  15. Quantum correlated imaging is a promising new technique in medical imaging

    Institute of Scientific and Technical Information of China (English)

    Nan Zhang; Zhaohua Yang

    2017-01-01

    Cardio-cerebral vascular diseases are common and frequently occurring serious diseases that threaten humans. In recent years, Digital Subtraction Angiography (DSA) has played a vital role in the diagnosis and treatment of cardio-cerebral vascular diseases. However, DSA is not able to visualize intravascular structures in real time, and it is especially difficult to evaluate each layer of the vascular wall and the composition of atherosclerotic plaques with DSA. Quantum correlated imaging is a new technique that can be used to perform real-time online imaging of intravascular flow, vascular wall structure, and atherosclerotic plaque composition. Quantum correlated imaging is a promising new technique that will soon be used in the diagnosis and treatment of cardio-cerebral vascular diseases.

  16. Terahertz composite imaging method

    Institute of Scientific and Technical Information of China (English)

    QIAO Xiaoli; REN Jiaojiao; ZHANG Dandan; CAO Guohua; LI Lijuan; ZHANG Xinming

    2017-01-01

    In order to improve the imaging quality of terahertz(THz) spectroscopy, Terahertz Composite Imaging Method(TCIM) is proposed. The traditional methods of improving THz spectroscopy image quality are mainly from the aspects of de-noising and image enhancement. TCIM breaks through this limitation. A set of images, reconstructed in a single data collection, can be utilized to construct two kinds of composite images. One algorithm, called Function Superposition Imaging Algorithm(FSIA), is to construct a new gray image utilizing multiple gray images through a certain function. The features of the Region Of Interest (ROI) are more obvious after operating, and it has capability of merging ROIs in multiple images. The other, called Multi-characteristics Pseudo-color Imaging Algorithm(McPcIA), is to construct a pseudo-color image by combining multiple reconstructed gray images in a single data collection. The features of ROI are enhanced by color differences. Two algorithms can not only improve the contrast of ROIs, but also increase the amount of information resulting in analysis convenience. The experimental results show that TCIM is a simple and effective tool for THz spectroscopy image analysis.

  17. Imaging workstations for computer-aided primatology: promises and pitfalls.

    Science.gov (United States)

    Vannier, M W; Conroy, G C

    1989-01-01

    In this paper, the application of biomedical imaging workstations to primatology will be explained and evaluated. The technological basis, computer hardware and software aspects, and the various uses of several types of workstations will all be discussed. The types of workstations include: (1) Simple - these display-only workstations, which function as electronic light boxes, have applications as terminals to picture archiving and communication (PAC) systems. (2) Diagnostic reporting - image-processing workstations that include the ability to perform straightforward manipulations of gray scale and raw data values will be considered for operations such as histogram equalization (whether adaptive or global), gradient edge finders, contour generation, and region of interest, as well as other related functions. (3) Manipulation systems - three-dimensional modeling and computer graphics with application to radiation therapy treatment planning, and surgical planning and evaluation will be considered. A technology of prime importance in the function of these workstations lies in communications and networking. The hierarchical organization of an electronic computer network and workstation environment with the interrelationship of simple, diagnostic reporting, and manipulation workstations to a coaxial or fiber optic network will be analyzed.

  18. Stem Cell Therapy: A Promising Therapeutic Method for Intracerebral Hemorrhage.

    Science.gov (United States)

    Gao, Liansheng; Xu, Weilin; Li, Tao; Chen, Jingyin; Shao, Anwen; Yan, Feng; Chen, Gao

    2018-01-01

    Spontaneous intracerebral hemorrhage (ICH) is one type of the most devastating cerebrovascular diseases worldwide, which causes high morbidity and mortality. However, efficient treatment is still lacking. Stem cell therapy has shown good neuroprotective and neurorestorative effect in ICH and is a promising treatment. In this study, our aim was to review the therapeutic effects, strategies, related mechanisms and safety issues of various types of stem cell for ICH treatment. Numerous studies had demonstrated the therapeutic effects of diverse stem cell types in ICH. The potential mechanisms include tissue repair and replacement, neurotrophy, promotion of neurogenesis and angiogenesis, anti-apoptosis, immunoregulation and anti-inflammation and so forth. The microenvironment of the central nervous system (CNS) can also influence the effects of stem cell therapy. The detailed therapeutic strategies for ICH treatment such as cell type, the number of cells, time window, and the routes of medication delivery, varied greatly among different studies and had not been determined. Moreover, the safety issues of stem cell therapy for ICH should not be ignored. Stem cell therapy showed good therapeutic effect in ICH, making it a promising treatment. However, safety should be carefully evaluated, and more clinical trials are required before stem cell therapy can be extensively applied to clinical use.

  19. Quantitative imaging methods in osteoporosis.

    Science.gov (United States)

    Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M Carola; Oei, Edwin H G

    2016-12-01

    Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.

  20. Rapid flow imaging method

    International Nuclear Information System (INIS)

    Pelc, N.J.; Spritzer, C.E.; Lee, J.N.

    1988-01-01

    A rapid, phase-contrast, MR imaging method of imaging flow has been implemented. The method, called VIGRE (velocity imaging with gradient recalled echoes), consists of two interleaved, narrow flip angle, gradient-recalled acquisitions. One is flow compensated while the second has a specified flow encoding (both peak velocity and direction) that causes signals to contain additional phase in proportion to velocity in the specified direction. Complex image data from the first acquisition are used as a phase reference for the second, yielding immunity from phase accumulation due to causes other than motion. Images with pixel values equal to MΔΘ where M is the magnitude of the flow compensated image and ΔΘ is the phase difference at the pixel, are produced. The magnitude weighting provides additional vessel contrast, suppresses background noise, maintains the flow direction information, and still allows quantitative data to be retrieved. The method has been validated with phantoms and is undergoing initial clinical evaluation. Early results are extremely encouraging

  1. Review of photoacoustic flow imaging: its current state and its promises

    NARCIS (Netherlands)

    van den Berg, P.J.; Daoudi, Khalid; Steenbergen, Wiendelt

    2015-01-01

    Flow imaging is an important method for quantification in many medical imaging modalities, with applications ranging from estimating wall shear rate to detecting angiogenesis. Modalities like ultrasound and optical coherence tomography both offer flow imaging capabilities, but suffer from low

  2. VAN method of short-term earthquake prediction shows promise

    Science.gov (United States)

    Uyeda, Seiya

    Although optimism prevailed in the 1970s, the present consensus on earthquake prediction appears to be quite pessimistic. However, short-term prediction based on geoelectric potential monitoring has stood the test of time in Greece for more than a decade [VarotsosandKulhanek, 1993] Lighthill, 1996]. The method used is called the VAN method.The geoelectric potential changes constantly due to causes such as magnetotelluric effects, lightning, rainfall, leakage from manmade sources, and electrochemical instabilities of electrodes. All of this noise must be eliminated before preseismic signals are identified, if they exist at all. The VAN group apparently accomplished this task for the first time. They installed multiple short (100-200m) dipoles with different lengths in both north-south and east-west directions and long (1-10 km) dipoles in appropriate orientations at their stations (one of their mega-stations, Ioannina, for example, now has 137 dipoles in operation) and found that practically all of the noise could be eliminated by applying a set of criteria to the data.

  3. Magnetic imager and method

    Science.gov (United States)

    Powell, James; Reich, Morris; Danby, Gordon

    1997-07-22

    A magnetic imager 10 includes a generator 18 for practicing a method of applying a background magnetic field over a concealed object, with the object being effective to locally perturb the background field. The imager 10 also includes a sensor 20 for measuring perturbations of the background field to detect the object. In one embodiment, the background field is applied quasi-statically. And, the magnitude or rate of change of the perturbations may be measured for determining location, size, and/or condition of the object.

  4. Methods in Astronomical Image Processing

    Science.gov (United States)

    Jörsäter, S.

    A Brief Introductory Note History of Astronomical Imaging Astronomical Image Data Images in Various Formats Digitized Image Data Digital Image Data Philosophy of Astronomical Image Processing Properties of Digital Astronomical Images Human Image Processing Astronomical vs. Computer Science Image Processing Basic Tools of Astronomical Image Processing Display Applications Calibration of Intensity Scales Calibration of Length Scales Image Re-shaping Feature Enhancement Noise Suppression Noise and Error Analysis Image Processing Packages: Design of AIPS and MIDAS AIPS MIDAS Reduction of CCD Data Bias Subtraction Clipping Preflash Subtraction Dark Subtraction Flat Fielding Sky Subtraction Extinction Correction Deconvolution Methods Rebinning/Combining Summary and Prospects for the Future

  5. Prognostic aspects of imaging method development

    International Nuclear Information System (INIS)

    Steinhart, L.

    1987-01-01

    A survey is presented of X-ray diagnostic methods and techniques and possibilities of their further development. Promising methods include direct imaging using digital radiography. In connection with computer technology these methods achieve higher resolution. The storage of obtained images in the computer memory will allow automated processing and evaluation and the use of expert systems. Development is expected to take place especially in computerized tomography using magnetic resonance, and positron computed tomography and other non-radioactive diagnostic methods. (J.B.). 5 figs., 1 tab., 1 ref

  6. Review of photoacoustic flow imaging: its current state and its promises.

    Science.gov (United States)

    van den Berg, P J; Daoudi, K; Steenbergen, W

    2015-09-01

    Flow imaging is an important method for quantification in many medical imaging modalities, with applications ranging from estimating wall shear rate to detecting angiogenesis. Modalities like ultrasound and optical coherence tomography both offer flow imaging capabilities, but suffer from low contrast to red blood cells and are sensitive to clutter artefacts. Photoacoustic imaging (PAI) is a relatively new field, with a recent interest in flow imaging. The recent enthusiasm for PA flow imaging is due to its intrinsic contrast to haemoglobin, which offers a new spin on existing methods of flow imaging, and some unique approaches in addition. This review article will delve into the research on photoacoustic flow imaging, explain the principles behind the many techniques and comment on their individual advantages and disadvantages.

  7. Nanoparticles for cancer imaging: The good, the bad, and the promise

    Science.gov (United States)

    Chapman, Sandra; Dobrovolskaia, Marina; Farahani, Keyvan; Goodwin, Andrew; Joshi, Amit; Lee, Hakho; Meade, Thomas; Pomper, Martin; Ptak, Krzysztof; Rao, Jianghong; Singh, Ravi; Sridhar, Srinivas; Stern, Stephan; Wang, Andrew; Weaver, John B.; Woloschak, Gayle; Yang, Lily

    2014-01-01

    Summary Recent advances in molecular imaging and nanotechnology are providing new opportunities for biomedical imaging with great promise for the development of novel imaging agents. The unique optical, magnetic, and chemical properties of materials at the scale of nanometers allow the creation of imaging probes with better contrast enhancement, increased sensitivity, controlled biodistribution, better spatial and temporal information, multi-functionality and multi-modal imaging across MRI, PET, SPECT, and ultrasound. These features could ultimately translate to clinical advantages such as earlier detection, real time assessment of disease progression and personalized medicine. However, several years of investigation into the application of these materials to cancer research has revealed challenges that have delayed the successful application of these agents to the field of biomedical imaging. Understanding these challenges is critical to take full advantage of the benefits offered by nano-sized imaging agents. Therefore, this article presents the lessons learned and challenges encountered by a group of leading researchers in this field, and suggests ways forward to develop nanoparticle probes for cancer imaging. Published by Elsevier Ltd. PMID:25419228

  8. Hyperspectral image processing methods

    Science.gov (United States)

    Hyperspectral image processing refers to the use of computer algorithms to extract, store and manipulate both spatial and spectral information contained in hyperspectral images across the visible and near-infrared portion of the electromagnetic spectrum. A typical hyperspectral image processing work...

  9. Image registration method for medical image sequences

    Science.gov (United States)

    Gee, Timothy F.; Goddard, James S.

    2013-03-26

    Image registration of low contrast image sequences is provided. In one aspect, a desired region of an image is automatically segmented and only the desired region is registered. Active contours and adaptive thresholding of intensity or edge information may be used to segment the desired regions. A transform function is defined to register the segmented region, and sub-pixel information may be determined using one or more interpolation methods.

  10. Evolution of Neutron Imaging at TRIGA PUSPATI Reactor: A Promising Digital Real-Time Imaging

    International Nuclear Information System (INIS)

    Khairiah Yazid; Muhammad Rawi Mohamed Zin; Rafhayudi Jamro; Azraf Azman

    2016-01-01

    Neutron radiography is a powerful tool for non-destructive testing of materials and finds numerous applications in industry and in material research as well. The basic principle is similar to that of X-ray radiography. A beam of neutrons falls on the sample and after passing through the sample, leaves the sample image on a photographic plate or on a detector. The neutrons interact with the nuclei of the atoms that compose the sample and the absorption and scattering properties of the contained elements make it possible to produce images of components containing light elements, like hydrogen beneath a matrix of metallic elements, (lead or bismuth), which cannot be easily done with conventional X ray radiography. Exploiting this property, neutron radiography has been used in applications requiring the identification of (light) materials inside solid samples. This article gives an overview of utilization of the CCD camera system in neutron imaging system for real time radiography/ tomography investigations. (author)

  11. Soft tissue tumors - imaging methods

    International Nuclear Information System (INIS)

    Arlart, I.P.

    1985-01-01

    Soft Tissue Tumors - Imaging Methods: Imaging methods play an important diagnostic role in soft tissue tumors concerning a preoperative evaluation of localization, size, topographic relationship, dignity, and metastatic disease. The present paper gives an overview about diagnostic methods available today such as ultrasound, thermography, roentgenographic plain films and xeroradiography, radionuclide methods, computed tomography, lymphography, angiography, and magnetic resonance imaging. Besides sonography particularly computed tomography has the most important diagnostic value in soft tissue tumors. The application of a recently developed method, the magnetic resonance imaging, cannot yet be assessed in its significance. (orig.) [de

  12. Automated X-ray image analysis for cargo security: Critical review and future promise.

    Science.gov (United States)

    Rogers, Thomas W; Jaccard, Nicolas; Morton, Edward J; Griffin, Lewis D

    2017-01-01

    We review the relatively immature field of automated image analysis for X-ray cargo imagery. There is increasing demand for automated analysis methods that can assist in the inspection and selection of containers, due to the ever-growing volumes of traded cargo and the increasing concerns that customs- and security-related threats are being smuggled across borders by organised crime and terrorist networks. We split the field into the classical pipeline of image preprocessing and image understanding. Preprocessing includes: image manipulation; quality improvement; Threat Image Projection (TIP); and material discrimination and segmentation. Image understanding includes: Automated Threat Detection (ATD); and Automated Contents Verification (ACV). We identify several gaps in the literature that need to be addressed and propose ideas for future research. Where the current literature is sparse we borrow from the single-view, multi-view, and CT X-ray baggage domains, which have some characteristics in common with X-ray cargo.

  13. Computational methods for molecular imaging

    CERN Document Server

    Shi, Kuangyu; Li, Shuo

    2015-01-01

    This volume contains original submissions on the development and application of molecular imaging computing. The editors invited authors to submit high-quality contributions on a wide range of topics including, but not limited to: • Image Synthesis & Reconstruction of Emission Tomography (PET, SPECT) and other Molecular Imaging Modalities • Molecular Imaging Enhancement • Data Analysis of Clinical & Pre-clinical Molecular Imaging • Multi-Modal Image Processing (PET/CT, PET/MR, SPECT/CT, etc.) • Machine Learning and Data Mining in Molecular Imaging. Molecular imaging is an evolving clinical and research discipline enabling the visualization, characterization and quantification of biological processes taking place at the cellular and subcellular levels within intact living subjects. Computational methods play an important role in the development of molecular imaging, from image synthesis to data analysis and from clinical diagnosis to therapy individualization. This work will bring readers fro...

  14. Imaging Apparatus And Method

    NARCIS (Netherlands)

    Manohar, Srirang; van Leeuwen, A.G.J.M.

    2010-01-01

    A thermoacoustic imaging apparatus comprises an electromagnetic radiation source configured to irradiate a sample area and an acoustic signal detection probe arrangement for detecting acoustic signals. A radiation responsive acoustic signal generator is added outside the sample area. The detection

  15. IMAGING APPARATUS AND METHOD

    NARCIS (Netherlands)

    Manohar, Srirang; van Leeuwen, A.G.J.M.

    2008-01-01

    A thermoacoustic imaging apparatus comprises an electromagnetic radiation source configured to irradiate a sample area and an acoustic signal detection probe arrangement for detecting acoustic signals. A radiation responsive acoustic signal generator is added outside the sample area. The detection

  16. Methods of digital image processing

    International Nuclear Information System (INIS)

    Doeler, W.

    1985-01-01

    Increasing use of computerized methods for diagnostical imaging of radiological problems will open up a wide field of applications for digital image processing. The requirements set by routine diagnostics in medical radiology point to picture data storage and documentation and communication as the main points of interest for application of digital image processing. As to the purely radiological problems, the value of digital image processing is to be sought in the improved interpretability of the image information in those cases where the expert's experience and image interpretation by human visual capacities do not suffice. There are many other domains of imaging in medical physics where digital image processing and evaluation is very useful. The paper reviews the various methods available for a variety of problem solutions, and explains the hardware available for the tasks discussed. (orig.) [de

  17. An Image Registration Method for Colposcopic Images

    Directory of Open Access Journals (Sweden)

    Efrén Mezura-Montes

    2013-01-01

    sequence and a division of such image into small windows. A search process is then carried out to find the window with the highest affinity in each image of the sequence and replace it with the window in the reference image. The affinity value is based on polynomial approximation of the time series computed and the search is bounded by a search radius which defines the neighborhood of each window. The proposed approach is tested in ten 310-frame real cases in two experiments: the first one to determine the best values for the window size and the search radius and the second one to compare the best obtained results with respect to four registration methods found in the specialized literature. The obtained results show a robust and competitive performance of the proposed approach with a significant lower time with respect to the compared methods.

  18. Imaging methods in otorhinolaryngology

    International Nuclear Information System (INIS)

    Frey, K.W.; Mees, K.; Vogl, T.

    1989-01-01

    This book is the work of an otorhinolaryngologist and two radiologists, who combined their experience and efforts in order to solve a great variety and number of problems encountered in practical work, taking into account the latest technical potentials and the practical feasibility, which is determined by the equipment available. Every chapter presents the full range of diagnostic methods applicable, starting with the suitable plain radiography methods and proceeding to the various tomographic scanning methods, including conventional tomography. Every technique is assessed in terms of diagnostic value and drawbacks. (orig./MG) With 778 figs [de

  19. Image restoration and processing methods

    International Nuclear Information System (INIS)

    Daniell, G.J.

    1984-01-01

    This review will stress the importance of using image restoration techniques that deal with incomplete, inconsistent, and noisy data and do not introduce spurious features into the processed image. No single image is equally suitable for both the resolution of detail and the accurate measurement of intensities. A good general purpose technique is the maximum entropy method and the basis and use of this will be explained. (orig.)

  20. Promises and challenges for the implementation of computational medical imaging (radiomics) in oncology.

    Science.gov (United States)

    Limkin, E J; Sun, R; Dercle, L; Zacharaki, E I; Robert, C; Reuzé, S; Schernberg, A; Paragios, N; Deutsch, E; Ferté, C

    2017-06-01

    Medical image processing and analysis (also known as Radiomics) is a rapidly growing discipline that maps digital medical images into quantitative data, with the end goal of generating imaging biomarkers as decision support tools for clinical practice. The use of imaging data from routine clinical work-up has tremendous potential in improving cancer care by heightening understanding of tumor biology and aiding in the implementation of precision medicine. As a noninvasive method of assessing the tumor and its microenvironment in their entirety, radiomics allows the evaluation and monitoring of tumor characteristics such as temporal and spatial heterogeneity. One can observe a rapid increase in the number of computational medical imaging publications-milestones that have highlighted the utility of imaging biomarkers in oncology. Nevertheless, the use of radiomics as clinical biomarkers still necessitates amelioration and standardization in order to achieve routine clinical adoption. This Review addresses the critical issues to ensure the proper development of radiomics as a biomarker and facilitate its implementation in clinical practice. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Methods in quantitative image analysis.

    Science.gov (United States)

    Oberholzer, M; Ostreicher, M; Christen, H; Brühlmann, M

    1996-05-01

    histogram of an existing image (input image) into a new grey value histogram (output image) are most quickly handled by a look-up table (LUT). The histogram of an image can be influenced by gain, offset and gamma of the camera. Gain defines the voltage range, offset defines the reference voltage and gamma the slope of the regression line between the light intensity and the voltage of the camera. A very important descriptor of neighbourhood relations in an image is the co-occurrence matrix. The distance between the pixels (original pixel and its neighbouring pixel) can influence the various parameters calculated from the co-occurrence matrix. The main goals of image enhancement are elimination of surface roughness in an image (smoothing), correction of defects (e.g. noise), extraction of edges, identification of points, strengthening texture elements and improving contrast. In enhancement, two types of operations can be distinguished: pixel-based (point operations) and neighbourhood-based (matrix operations). The most important pixel-based operations are linear stretching of grey values, application of pre-stored LUTs and histogram equalisation. The neighbourhood-based operations work with so-called filters. These are organising elements with an original or initial point in their centre. Filters can be used to accentuate or to suppress specific structures within the image. Filters can work either in the spatial or in the frequency domain. The method used for analysing alterations of grey value intensities in the frequency domain is the Hartley transform. Filter operations in the spatial domain can be based on averaging or ranking the grey values occurring in the organising element. The most important filters, which are usually applied, are the Gaussian filter and the Laplace filter (both averaging filters), and the median filter, the top hat filter and the range operator (all ranking filters). Segmentation of objects is traditionally based on threshold grey values. (AB

  2. Numerical methods for image registration

    CERN Document Server

    Modersitzki, Jan

    2003-01-01

    Based on the author's lecture notes and research, this well-illustrated and comprehensive text is one of the first to provide an introduction to image registration with particular emphasis on numerical methods in medical imaging. Ideal for researchers in industry and academia, it is also a suitable study guide for graduate mathematicians, computer scientists, engineers, medical physicists, and radiologists.Image registration is utilised whenever information obtained from different viewpoints needs to be combined or compared and unwanted distortion needs to be eliminated. For example, CCTV imag

  3. Twin-Foucault imaging method

    Science.gov (United States)

    Harada, Ken

    2012-02-01

    A method of Lorentz electron microscopy, which enables observation two Foucault images simultaneously by using an electron biprism instead of an objective aperture, was developed. The electron biprism is installed between two electron beams deflected by 180° magnetic domains. Potential applied to the biprism deflects the two electron beams further, and two Foucault images with reversed contrast are then obtained in one visual field. The twin Foucault images are able to extract the magnetic domain structures and to reconstruct an ordinary electron micrograph. The developed Foucault method was demonstrated with a 180° domain structure of manganite La0.825Sr0.175MnO3.

  4. PROspective Multicenter Imaging Study for Evaluation of chest pain: rationale and design of the PROMISE trial.

    Science.gov (United States)

    Douglas, Pamela S; Hoffmann, Udo; Lee, Kerry L; Mark, Daniel B; Al-Khalidi, Hussein R; Anstrom, Kevin; Dolor, Rowena J; Kosinski, Andrzej; Krucoff, Mitchell W; Mudrick, Daniel W; Patel, Manesh R; Picard, Michael H; Udelson, James E; Velazquez, Eric J; Cooper, Lawton

    2014-06-01

    Suspected coronary artery disease (CAD) is one of the most common, potentially life-threatening diagnostic problems clinicians encounter. However, no large outcome-based randomized trials have been performed to guide the selection of diagnostic strategies for these patients. The PROMISE study is a prospective, randomized trial comparing the effectiveness of 2 initial diagnostic strategies in patients with symptoms suspicious for CAD. Patients are randomized to either (1) functional testing (exercise electrocardiogram, stress nuclear imaging, or stress echocardiogram) or (2) anatomical testing with ≥64-slice multidetector coronary computed tomographic angiography. Tests are interpreted locally in real time by subspecialty certified physicians, and all subsequent care decisions are made by the clinical care team. Sites are provided results of central core laboratory quality and completeness assessment. All subjects are followed up for ≥1 year. The primary end point is the time to occurrence of the composite of death, myocardial infarction, major procedural complications (stroke, major bleeding, anaphylaxis, and renal failure), or hospitalization for unstable angina. More than 10,000 symptomatic subjects were randomized in 3.2 years at 193 US and Canadian cardiology, radiology, primary care, urgent care, and anesthesiology sites. Multispecialty community practice enrollment into a large pragmatic trial of diagnostic testing strategies is both feasible and efficient. The PROMISE trial will compare the clinical effectiveness of an initial strategy of functional testing against an initial strategy of anatomical testing in symptomatic patients with suspected CAD. Quality of life, resource use, cost-effectiveness, and radiation exposure will be assessed. Copyright © 2014 Mosby, Inc. All rights reserved.

  5. Image portion identification methods, image parsing methods, image parsing systems, and articles of manufacture

    Science.gov (United States)

    Lassahn, Gordon D.; Lancaster, Gregory D.; Apel, William A.; Thompson, Vicki S.

    2013-01-08

    Image portion identification methods, image parsing methods, image parsing systems, and articles of manufacture are described. According to one embodiment, an image portion identification method includes accessing data regarding an image depicting a plurality of biological substrates corresponding to at least one biological sample and indicating presence of at least one biological indicator within the biological sample and, using processing circuitry, automatically identifying a portion of the image depicting one of the biological substrates but not others of the biological substrates.

  6. Mathematical methods in elasticity imaging

    CERN Document Server

    Ammari, Habib; Garnier, Josselin; Kang, Hyeonbae; Lee, Hyundae; Wahab, Abdul

    2015-01-01

    This book is the first to comprehensively explore elasticity imaging and examines recent, important developments in asymptotic imaging, modeling, and analysis of deterministic and stochastic elastic wave propagation phenomena. It derives the best possible functional images for small inclusions and cracks within the context of stability and resolution, and introduces a topological derivative-based imaging framework for detecting elastic inclusions in the time-harmonic regime. For imaging extended elastic inclusions, accurate optimal control methodologies are designed and the effects of uncertainties of the geometric or physical parameters on stability and resolution properties are evaluated. In particular, the book shows how localized damage to a mechanical structure affects its dynamic characteristics, and how measured eigenparameters are linked to elastic inclusion or crack location, orientation, and size. Demonstrating a novel method for identifying, locating, and estimating inclusions and cracks in elastic...

  7. Urokinase-type plasminogen activator receptor (uPAR) as a promising new imaging target

    DEFF Research Database (Denmark)

    Persson, Morten; Kjaer, Andreas

    2013-01-01

    modalities such as optical imaging, magnetic resonance imaging, single photon emission computer tomography (SPECT) and positron emission topography (PET). In this review, we will discuss recent advances in the development of uPAR-targeted imaging ligands according to imaging modality. In addition, we...... will discuss the potential future clinical application for uPAR imaging as a new imaging biomarker....

  8. Magnetic Resonance Fingerprinting - a promising new approach to obtain standardized imaging biomarkers from MRI.

    Science.gov (United States)

    2015-04-01

    Current routine MRI examinations rely on the acquisition of qualitative images that have a contrast "weighted" for a mixture of (magnetic) tissue properties. Recently, a novel approach was introduced, namely MR Fingerprinting (MRF) with a completely different approach to data acquisition, post-processing and visualization. Instead of using a repeated, serial acquisition of data for the characterization of individual parameters of interest, MRF uses a pseudo randomized acquisition that causes the signals from different tissues to have a unique signal evolution or 'fingerprint' that is simultaneously a function of the multiple material properties under investigation. The processing after acquisition involves a pattern recognition algorithm to match the fingerprints to a predefined dictionary of predicted signal evolutions. These can then be translated into quantitative maps of the magnetic parameters of interest. MR Fingerprinting (MRF) is a technique that could theoretically be applied to most traditional qualitative MRI methods and replaces them with acquisition of truly quantitative tissue measures. MRF is, thereby, expected to be much more accurate and reproducible than traditional MRI and should improve multi-center studies and significantly reduce reader bias when diagnostic imaging is performed. Key Points • MR fingerprinting (MRF) is a new approach to data acquisition, post-processing and visualization.• MRF provides highly accurate quantitative maps of T1, T2, proton density, diffusion.• MRF may offer multiparametric imaging with high reproducibility, and high potential for multicenter/ multivendor studies.

  9. [Promising new injection method to prevent angialgia/phlebitis from epirubicin hydrochloride therapy for breast cancer].

    Science.gov (United States)

    Ono, Chiemi; Yamagami, Mitsue; Kamatani, Rika; Yamamoto, Makoto; Mukouyama, Tomoya; Sugimoto, Masakazu; Suzuki, Taizan; Kamo, Nobuyuki; Seki, Nobuhiko; Eguchi, Kenji; Ikeda, Tadashi

    2012-05-01

    Epirubicin hydrochloride(EPI)is well known to cause phlebitis as a typical adverse drug reaction. By preventing the development of severe phlebitis, patients are expected to continue effective chemotherapy with EPI without a decrease in QOL. We have previously reported promising results of a new injection method to prevent phlebitis from occurring during EPI therapy thorough a prospective clinical trial in our hospital(Jpn J Cancer Chemother 36: 969-974, 2009). In the present study, we have compared the conventional injection method(EPI main -route method, n=15)with our new method, which has been consistently practiced at present(EPI sub -route method, n=77). We found that in the EPI main -route method, angialgia/phlebitis developed in 14 of 15 cases(Grade 3, 53. 3%), leading to alteration of the regimen in 3 cases. On the other hand, with the EPI sub -route method, incidence of angialgia/phlebitis was markedly decreased, and only 6 of 77 cases developed these adverse reactions(Grade 3, 0%). One possible explanation for these results is that the reduction of intimal stimulation by the EPI sub -route method might be caused by the dilution and washout of EPI with pre-medication, as well as the shortened infusion times of EPI. Therefore, on the basis of the above hypothesis, we conclude that the EPI sub-route method might be a more effective treatment for the expected prevention of angialgia/phlebitis.

  10. Simultaneous multislice echo planar imaging with blipped controlled aliasing in parallel imaging results in higher acceleration: a promising technique for accelerated diffusion tensor imaging of skeletal muscle

    OpenAIRE

    Filli, Lukas; Piccirelli, Marco; Kenkel, David; Guggenberger, Roman; Andreisek, Gustav; Beck, Thomas; Runge, Val M; Boss, Andreas

    2015-01-01

    PURPOSE The aim of this study was to investigate the feasibility of accelerated diffusion tensor imaging (DTI) of skeletal muscle using echo planar imaging (EPI) applying simultaneous multislice excitation with a blipped controlled aliasing in parallel imaging results in higher acceleration unaliasing technique. MATERIALS AND METHODS After federal ethics board approval, the lower leg muscles of 8 healthy volunteers (mean [SD] age, 29.4 [2.9] years) were examined in a clinical 3-T magnetic ...

  11. Methods of producing luminescent images

    International Nuclear Information System (INIS)

    Broadhead, P.; Newman, G.A.

    1977-01-01

    A method is described for producing a luminescent image in a layer of a binding material in which is dispersed a thermoluminescent material. The layer is heated uniformly to a temperature of 80 to 300 0 C and is exposed to luminescence inducing radiation whilst so heated. The preferred exposing radiation is X-rays and preferably the thermoluminescent material is insensitive to electromagnetic radiation of wavelength longer than 300 mm. Information concerning preparation of the luminescent material is given in BP 1,347,672; this material has the advantage that at elevated temperatures it shows increased sensitivity compared with room temperature. At temperatures in the range 80 to 150 0 C the thermoluminescent material exhibits 'afterglow', allowing the image to persist for several seconds after the X-radiation has ceased, thus allowing the image to be retained for visual inspection in this temperature range. At higher temperatures, however, there is negligible 'afterglow'. The thermoluminescent layers so produced are particularly useful as fluoroscopic screens. The preferred method of heating the thermoluminescent material is described in BP 1,354,149. An example is given of the application of the method. (U.K.)

  12. The promise of mixed-methods for advancing latino health research.

    Science.gov (United States)

    Apesoa-Varano, Ester Carolina; Hinton, Ladson

    2013-09-01

    Mixed-methods research in the social sciences has been conducted for quite some time. More recently, mixed-methods have become popular in health research, with the National Institutes of Health leading the impetus to fund studies that implement such an approach. The public health issues facing us today are great and they range from policy and other macro-level issues, to systems level problems to individuals' health behaviors. For Latinos, who are projected to become the largest minority group bearing a great deal of the burden of social inequality in the U.S., it is important to understand the deeply-rooted nature of these health disparities in order to close the gap in health outcomes. Mixed-methodology thus holds promise for advancing research on Latino heath by tackling health disparities from a variety of standpoints and approaches. The aim of this manuscript is to provide two examples of mixed methods research, each of which addresses a health topic of considerable importance to older Latinos and their families. These two examples will illustrate a) the complementary use of qualitative and quantitative methods to advance health of older Latinos in an area that is important from a public health perspective, and b) the "translation" of findings from observational studies (informed by social science and medicine) to the development and testing of interventions.

  13. Digital image processing mathematical and computational methods

    CERN Document Server

    Blackledge, J M

    2005-01-01

    This authoritative text (the second part of a complete MSc course) provides mathematical methods required to describe images, image formation and different imaging systems, coupled with the principle techniques used for processing digital images. It is based on a course for postgraduates reading physics, electronic engineering, telecommunications engineering, information technology and computer science. This book relates the methods of processing and interpreting digital images to the 'physics' of imaging systems. Case studies reinforce the methods discussed, with examples of current research

  14. A method of image improvement in three-dimensional imaging

    International Nuclear Information System (INIS)

    Suto, Yasuzo; Huang, Tewen; Furuhata, Kentaro; Uchino, Masafumi.

    1988-01-01

    In general, image interpolation is required when the surface configurations of such structures as bones and organs are three-dimensionally constructed from the multi-sliced images obtained by CT. Image interpolation is a processing method whereby an artificial image is inserted between two adjacent slices to make spatial resolution equal to slice resolution in appearance. Such image interpolation makes it possible to increase the image quality of the constructed three-dimensional image. In our newly-developed algorithm, we have converted the presently and subsequently sliced images to distance images, and generated the interpolation images from these two distance images. As a result, compared with the previous method, three-dimensional images with better image quality have been constructed. (author)

  15. Method of assessing heterogeneity in images

    Science.gov (United States)

    Jacob, Richard E.; Carson, James P.

    2016-08-23

    A method of assessing heterogeneity in images is disclosed. 3D images of an object are acquired. The acquired images may be filtered and masked. Iterative decomposition is performed on the masked images to obtain image subdivisions that are relatively homogeneous. Comparative analysis, such as variogram analysis or correlogram analysis, is performed of the decomposed images to determine spatial relationships between regions of the images that are relatively homogeneous.

  16. 99mTc-thymine scintigraphy may be a promising method in the diagnosis of breast cancer

    International Nuclear Information System (INIS)

    Ribeiro, Monica Pires; Souza, Sergio Augusto Lopes de; Lopes, Flavia Paiva Proenca Lobo; Rosado-de-Castro, Paulo Henrique; Fonseca, Lea Mirian Barbosa da; Gutfilen, Bianca

    2013-01-01

    Objective: Mammography has been established as the gold standard for the detection of breast cancer, and imaging techniques such as ultrasonography, magnetic resonance imaging, scintigraphy and positron emission tomography may be useful to improve its sensitivity and specificity. The objective of this study with breast scintigraphy was to evaluate the uptake of 99m Tc-thymine in mammary lesions. Methods: A total of 45 patients were included in this study. Thirty-three patients (73%) were subjected to surgery or percutaneous biopsy, providing histopathological data. The other 12 patients who remained under surveillance received clinical examinations and biannual mammography with a normal follow-up of at least three years, the data from which were used for comparison with the scintimammography results. Results: The majority of patients (64.4%) had clinically impalpable lesions with a mammogram diagnosis of microcalcifications, impalpable nodules, or focal asymmetry. Of the studied lesions, 87% were smaller or equal to 20 mm in diameter, and 22% had malignant histopathological findings. Scintigraphy with 99m Tc-thymine had a sensitivity of 70%, a specificity of 85.7%, positive and negative predictive values of 58.3% and 90.9%, respectively, and an accuracy of 82.2%. Conclusions: The results of this study are consistent with those previously reported by other authors. The good specificity and high negative predictive value of this technique and the absence of uptake in the heart indicate that it may be a promising complementary method in clinical practice and that it may contribute to reducing unnecessary benign biopsies. (author)

  17. 99mTc-thymine scintigraphy may be a promising method in the diagnosis of breast cancer

    Directory of Open Access Journals (Sweden)

    Monica Pires Ribeiro

    2013-01-01

    Full Text Available OBJECTIVE: Mammography has been established as the gold standard for the detection of breast cancer, and imaging techniques such as ultrasonography, magnetic resonance imaging, scintigraphy and positron emission tomography may be useful to improve its sensitivity and specificity. The objective of this study with breast scintigraphy was to evaluate the uptake of 99mTc-thymine in mammary lesions. METHODS: A total of 45 patients were included in this study. Thirty-three patients (73% were subjected to surgery or percutaneous biopsy, providing histopathological data. The other 12 patients who remained under surveillance received clinical examinations and biannual mammography with a normal follow-up of at least three years, the data from which were used for comparison with the scintimammography results. RESULTS: The majority of patients (64.4% had clinically impalpable lesions with a mammogram diagnosis of microcalcifications, impalpable nodules, or focal asymmetry. Of the studied lesions, 87% were smaller or equal to 20 mm in diameter, and 22% had malignant histopathological findings. Scintigraphy with 99mTc-thymine had a sensitivity of 70%, a specificity of 85.7%, positive and negative predictive values of 58.3% and 90.9%, respectively, and an accuracy of 82.2%. CONCLUSIONS: The results of this study are consistent with those previously reported by other authors. The good specificity and high negative predictive value of this technique and the absence of uptake in the heart indicate that it may be a promising complementary method in clinical practice and that it may contribute to reducing unnecessary benign biopsies.

  18. 99mTc-thymine scintigraphy may be a promising method in the diagnosis of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Monica Pires; Souza, Sergio Augusto Lopes de; Lopes, Flavia Paiva Proenca Lobo; Rosado-de-Castro, Paulo Henrique; Fonseca, Lea Mirian Barbosa da; Gutfilen, Bianca [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina. Hospital Universitario Clementino Fraga Filho, Departamento de Radiologia

    2013-05-01

    Objective: Mammography has been established as the gold standard for the detection of breast cancer, and imaging techniques such as ultrasonography, magnetic resonance imaging, scintigraphy and positron emission tomography may be useful to improve its sensitivity and specificity. The objective of this study with breast scintigraphy was to evaluate the uptake of {sup 99m}Tc-thymine in mammary lesions. Methods: A total of 45 patients were included in this study. Thirty-three patients (73%) were subjected to surgery or percutaneous biopsy, providing histopathological data. The other 12 patients who remained under surveillance received clinical examinations and biannual mammography with a normal follow-up of at least three years, the data from which were used for comparison with the scintimammography results. Results: The majority of patients (64.4%) had clinically impalpable lesions with a mammogram diagnosis of microcalcifications, impalpable nodules, or focal asymmetry. Of the studied lesions, 87% were smaller or equal to 20 mm in diameter, and 22% had malignant histopathological findings. Scintigraphy with {sup 99m}Tc-thymine had a sensitivity of 70%, a specificity of 85.7%, positive and negative predictive values of 58.3% and 90.9%, respectively, and an accuracy of 82.2%. Conclusions: The results of this study are consistent with those previously reported by other authors. The good specificity and high negative predictive value of this technique and the absence of uptake in the heart indicate that it may be a promising complementary method in clinical practice and that it may contribute to reducing unnecessary benign biopsies. (author)

  19. COMPARISON OF IMAGE ENHANCEMENT METHODS FOR CHROMOSOME KARYOTYPE IMAGE ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    Dewa Made Sri Arsa

    2017-02-01

    Full Text Available The chromosome is a set of DNA structure that carry information about our life. The information can be obtained through Karyotyping. The process requires a clear image so the chromosome can be evaluate well. Preprocessing have to be done on chromosome images that is image enhancement. The process starts with image background removing. The image will be cleaned background color. The next step is image enhancement. This paper compares several methods for image enhancement. We evaluate some method in image enhancement like Histogram Equalization (HE, Contrast-limiting Adaptive Histogram Equalization (CLAHE, Histogram Equalization with 3D Block Matching (HE+BM3D, and basic image enhancement, unsharp masking. We examine and discuss the best method for enhancing chromosome image. Therefore, to evaluate the methods, the original image was manipulated by the addition of some noise and blur. Peak Signal-to-noise Ratio (PSNR and Structural Similarity Index (SSIM are used to examine method performance. The output of enhancement method will be compared with result of Professional software for karyotyping analysis named Ikaros MetasystemT M . Based on experimental results, HE+BM3D method gets a stable result on both scenario noised and blur image.

  20. Magnetic Resonance Fingerprinting - a promising new approach to obtain standardized imaging biomarkers from MRI

    OpenAIRE

    2015-01-01

    Current routine MRI examinations rely on the acquisition of qualitative images that have a contrast ?weighted? for a mixture of (magnetic) tissue properties. Recently, a novel approach was introduced, namely MR Fingerprinting (MRF) with a completely different approach to data acquisition, post-processing and visualization. Instead of using a repeated, serial acquisition of data for the characterization of individual parameters of interest, MRF uses a pseudo randomized acquisition that causes ...

  1. Double-compression method for biomedical images

    Science.gov (United States)

    Antonenko, Yevhenii A.; Mustetsov, Timofey N.; Hamdi, Rami R.; Małecka-Massalska, Teresa; Orshubekov, Nurbek; DzierŻak, RóŻa; Uvaysova, Svetlana

    2017-08-01

    This paper describes a double compression method (DCM) of biomedical images. A comparison of image compression factors in size JPEG, PNG and developed DCM was carried out. The main purpose of the DCM - compression of medical images while maintaining the key points that carry diagnostic information. To estimate the minimum compression factor an analysis of the coding of random noise image is presented.

  2. Optoelectronic imaging of speckle using image processing method

    Science.gov (United States)

    Wang, Jinjiang; Wang, Pengfei

    2018-01-01

    A detailed image processing of laser speckle interferometry is proposed as an example for the course of postgraduate student. Several image processing methods were used together for dealing with optoelectronic imaging system, such as the partial differential equations (PDEs) are used to reduce the effect of noise, the thresholding segmentation also based on heat equation with PDEs, the central line is extracted based on image skeleton, and the branch is removed automatically, the phase level is calculated by spline interpolation method, and the fringe phase can be unwrapped. Finally, the imaging processing method was used to automatically measure the bubble in rubber with negative pressure which could be used in the tire detection.

  3. Color image definition evaluation method based on deep learning method

    Science.gov (United States)

    Liu, Di; Li, YingChun

    2018-01-01

    In order to evaluate different blurring levels of color image and improve the method of image definition evaluation, this paper proposed a method based on the depth learning framework and BP neural network classification model, and presents a non-reference color image clarity evaluation method. Firstly, using VGG16 net as the feature extractor to extract 4,096 dimensions features of the images, then the extracted features and labeled images are employed in BP neural network to train. And finally achieve the color image definition evaluation. The method in this paper are experimented by using images from the CSIQ database. The images are blurred at different levels. There are 4,000 images after the processing. Dividing the 4,000 images into three categories, each category represents a blur level. 300 out of 400 high-dimensional features are trained in VGG16 net and BP neural network, and the rest of 100 samples are tested. The experimental results show that the method can take full advantage of the learning and characterization capability of deep learning. Referring to the current shortcomings of the major existing image clarity evaluation methods, which manually design and extract features. The method in this paper can extract the images features automatically, and has got excellent image quality classification accuracy for the test data set. The accuracy rate is 96%. Moreover, the predicted quality levels of original color images are similar to the perception of the human visual system.

  4. Technetium-99m dextran: a promising new protein-losing enteropathy imaging agent

    International Nuclear Information System (INIS)

    Bhatnagar, A.; Singh, A.K.; Lahoti, D.; Singh, T.; Khanna, C.M.

    1996-01-01

    The purpose of this study was to evaluate technetium-99m dextran ( 99m Tc-Dx; molecular weight 81000) as a prospective protein-losing enteropathy (PLE) imaging agent. Twenty-two patients iwth diseases commonly associated with PLE and 12 healthy control subjects underwent intravenous 99m Tc-Dx scintigraphy. All of the 22 test patients showed significant radiotracer accumulation in the intestines within 3-4 h post injection. The focal, regional or generalised nature of the enteropathy and involvement of the large or small intestine could be identified in most cases. Four of the 12 apparently healthy subjects also showed minimal accumulation in the abdominal area occurring late in the study period. This could have been physiological, related to food habits or due to unsuspected intestinal worms. We attribute the high sensitivity of 99m Tc-Dx to its relatively fast blood (background) clearance. The radiotracer may have several other advantages over 99m Tc-labelled human serum albumin in imaging PLE. (orig.)

  5. Dynamic susceptibility contrast magnetic resonance imaging in neuropsychiatry: present utility and future promise

    International Nuclear Information System (INIS)

    Renshaw, P.F.; Levin, J.M.; Kaufman, M.J.; Ross, M.H.; Lewis, R.F.; Harris, G.J.

    1997-01-01

    Dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) provides a noninvasive means to create high resolution maps of the regional distribution of cerebral blood volume (CBV). Most DSC MRI studies conducted to date have focused on the evaluation of patients with cerebral neoplasms, ischemia or infarction, and epilepsy. However, preliminary work suggests that DSC MRI may also provide clinically important information for the evaluation of patients with neuropsychiatric disorders, especially dementia and schizophrenia. Additionally, with appropriate modification, DSC MRI may be used to reliably evaluate the effects of pharmacological challenges on cerebral hemodynamics. As pharmacotherapy is an important component in the treatment of a range of psychiatric disorders, the dynamic assessment of changes in cerebral perfusion associated with drug administration may ultimately lead to the development of ''brain function tests'' for a wide range of disorders. (orig.)

  6. Nuclear magnetic resonance imaging method

    International Nuclear Information System (INIS)

    Johnson, G.; MacDonald, J.; Hutchison, S.; Eastwood, L.M.; Redpath, T.W.T.; Mallard, J.R.

    1984-01-01

    A method of deriving three dimensional image information from an object using nuclear magnetic resonance signals comprises subjecting the object to a continuous, static magnetic field and carrying out the following set of sequential steps: 1) exciting nuclear spins in a selected volume (90deg pulse); 2) applying non-aligned first, second and third gradients of the magnetic field; 3) causing the spins to rephase periodically by reversal of the first gradient to produce spin echoes, and applying pulses of the second gradient prior to every read-out of an echo signal from the object, to differently encode the spin in the second gradient direction for each read-out signal. The above steps 1-3 are then successively repeated with different values of gradient of the third gradient, there being a recovery interval between the repetition of successive sets of steps. Alternate echoes only are read out, the other echoes being time-reversed and ignored for convenience. The resulting signals are appropriately sampled, set out in an array and subjected to three dimensional Fourier transformation. (author)

  7. Computational methods in molecular imaging technologies

    CERN Document Server

    Gunjan, Vinit Kumar; Venkatesh, C; Amarnath, M

    2017-01-01

    This book highlights the experimental investigations that have been carried out on magnetic resonance imaging and computed tomography (MRI & CT) images using state-of-the-art Computational Image processing techniques, and tabulates the statistical values wherever necessary. In a very simple and straightforward way, it explains how image processing methods are used to improve the quality of medical images and facilitate analysis. It offers a valuable resource for researchers, engineers, medical doctors and bioinformatics experts alike.

  8. Science and Its Images--Promise and Threat: From Classic Literature to Contemporary Students' Images of Science and "The Scientist"

    Science.gov (United States)

    Koren, Pazit; Bar, Varda

    2009-01-01

    The physical and social image of the scientist among school children, student teachers, and teachers over the last 50 years was investigated. Interest has also been shown in the perception of the personality behind the physical stereotype. Nevertheless, the value judgments of science and scientists and the positive and negative mind-sets attaching…

  9. Cytolysin a expressing E. coli a promising candidate for imageable therapeutic probe

    International Nuclear Information System (INIS)

    Nguyen, Vu Hong; Phan, Thuy Xuan; Hong, Yeoung Jin; Min, Jung Joon

    2007-01-01

    Using bacteria for cancer treatment has a long history. Discovery of optical reporter genes consisting of fluorescent and luminescent protein facilitates the monitor of bacteria in vivo, non-invasively and repeatedly. E. coli, the natural enteric bacteria possessing capacity of tumor-targeting ability, seems to be suitable candidate for cancer treatment. In this study, we established the strain light-emitting E. coli for diagnostic purpose and Cytolysin A (Cly A) expressing E. coli for therapeutic purpose. E. coli (MG1655, wild type strain) was transformed plasmid pUC19 carrying lux gene to create the light expressing bacteria and test the tumor targeting-capacity by injecting the bacteria into CT26-tumor bearing mice via tail vein. On the other hand, for therapeutic purpose, plasmid containing Cly A gene, which is encoded for a pore-forming protein toxin, was introduced into E. coli. The toxicity of Cly A was evaluated in vitro by inoculating the bacteria with various cultured cancer cell lines. On the other hand, to test the therapeutic effect, the bacteria were injected intratumorally and intravenously into s.c.CT26-bearing as well as CT26-lung metastasized Balb/c mice. In vivo imaging data showed that the E. coli strains selectively located in the tumor. The in vitro result showed that the number of death cells were significantly higher in the samples containing E. coli expressing Cly A (E. coli Cly A) compared with the samples containing wild type strain. The growth of tumors was repressed in mice injected with either E. coli Cly A (significantly) or wild type E. coli (mildly), while tumors in no treatment group still grew fast. Furthermore, the tumors inoculated with E. coli cly A were necrotized but not with wild type E. coli. In the CT26-lung metastasized mouse model, the life span of mice was elongated when inject E. coli and longer in the group injected with E. coli cly A. Cly A expressing E. coli can become an effective candidate for imageable

  10. Promising results with image guided intensity modulated radiotherapy for muscle invasive bladder cancer

    International Nuclear Information System (INIS)

    Whalley, D.; Caine, H.; McCloud, P.; Guo, L.; Kneebone, A.; Eade, T.

    2015-01-01

    To describe the feasibility of image guided intensity modulated radiotherapy (IG-IMRT) using daily soft tissue matching in the treatment of bladder cancer. Twenty-eight patients with muscle-invasive carcinoma of the bladder were recruited to a protocol of definitive radiation using IMRT with accelerated hypofractionation with simultaneous integrated boost (SIB). Isotropic margins of .5 and 1 cm were used to generate the high risk and intermediate risk planning target volumes respectively. Cone beam CT (CBCT) was acquired daily and a soft tissue match was performed. Cystoscopy was scheduled 6 weeks post treatment. The median age was 83 years (range 58-92). Twenty patients had stage II or III disease, and eight were stage IV. Gross disease received 66 Gy in 30 fractions in 11 patients (ten with concurrent chemotherapy) or 55 Gy in 20 fractions for those of poorer performance status or with palliative intent. All patients completed radiation treatment as planned. Three patients ceased chemotherapy early due to toxicity. Six patients (21 %) had acute Grade ≥ 2 genitourinary (GU) toxicity and six (21 %) had acute Grade ≥ 2 gastrointestinal (GI) toxicity. Five patients (18 %) developed Grade ≥2 late GU toxicity and no ≥2 late GI toxicity was observed. Nineteen patients underwent cystoscopy following radiation, with complete response (CR) in 16 cases (86 %), including all patients treated with chemoradiotherapy. Eight patients relapsed, four of which were local relapses. Of the patients with local recurrence, one underwent salvage cystectomy. For patients treated with definitive intent, freedom from locoregional recurrence (FFLR) and overall survival (OS) was 90 %/100 % for chemoradiotherapy versus 86 %/69 % for radiotherapy alone. IG- IMRT using daily soft tissue matching is a feasible in the treatment of bladder cancer, enabling the delivery of accelerated synchronous integrated boost with good early local control outcomes and low toxicity

  11. Review methods for image segmentation from computed tomography images

    International Nuclear Information System (INIS)

    Mamat, Nurwahidah; Rahman, Wan Eny Zarina Wan Abdul; Soh, Shaharuddin Cik; Mahmud, Rozi

    2014-01-01

    Image segmentation is a challenging process in order to get the accuracy of segmentation, automation and robustness especially in medical images. There exist many segmentation methods that can be implemented to medical images but not all methods are suitable. For the medical purposes, the aims of image segmentation are to study the anatomical structure, identify the region of interest, measure tissue volume to measure growth of tumor and help in treatment planning prior to radiation therapy. In this paper, we present a review method for segmentation purposes using Computed Tomography (CT) images. CT images has their own characteristics that affect the ability to visualize anatomic structures and pathologic features such as blurring of the image and visual noise. The details about the methods, the goodness and the problem incurred in the methods will be defined and explained. It is necessary to know the suitable segmentation method in order to get accurate segmentation. This paper can be a guide to researcher to choose the suitable segmentation method especially in segmenting the images from CT scan

  12. Signal to noise comparison of metabolic imaging methods on a clinical 3T MRI

    DEFF Research Database (Denmark)

    Müller, C. A.; Hansen, Rie Beck; Skinner, J. G.

    MRI with hyperpolarized tracers has enabled new diagnostic applications, e.g. metabolic imaging in cancer research. However, the acquisition of the transient, hyperpolarized signal with spatial and frequency resolution requires dedicated imaging methods. Here, we compare three promising candidate...... for 2D MR spectroscopic imaging (MRSI): (i) multi-echo balanced steady-state free precession (me-bSSFP), 1,2 (ii) echo planar spectroscopic imaging (EPSI) sequence and (iii) phase-encoded, pulseacquisition chemical-shift imaging (CSI)...

  13. Gamma-ray Imaging Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  14. WE-H-206-03: Promises and Challenges of Benchtop X-Ray Fluorescence CT (XFCT) for Quantitative in Vivo Imaging

    International Nuclear Information System (INIS)

    Cho, S.

    2016-01-01

    Lihong V. Wang: Photoacoustic tomography (PAT), combining non-ionizing optical and ultrasonic waves via the photoacoustic effect, provides in vivo multiscale functional, metabolic, and molecular imaging. Broad applications include imaging of the breast, brain, skin, esophagus, colon, vascular system, and lymphatic system in humans or animals. Light offers rich contrast but does not penetrate biological tissue in straight paths as x-rays do. Consequently, high-resolution pure optical imaging (e.g., confocal microscopy, two-photon microscopy, and optical coherence tomography) is limited to penetration within the optical diffusion limit (∼1 mm in the skin). Ultrasonic imaging, on the contrary, provides fine spatial resolution but suffers from both poor contrast in early-stage tumors and strong speckle artifacts. In PAT, pulsed laser light penetrates tissue and generates a small but rapid temperature rise, which induces emission of ultrasonic waves due to thermoelastic expansion. The ultrasonic waves, orders of magnitude less scattering than optical waves, are then detected to form high-resolution images of optical absorption at depths up to 7 cm, conquering the optical diffusion limit. PAT is the only modality capable of imaging across the length scales of organelles, cells, tissues, and organs (up to whole-body small animals) with consistent contrast. This rapidly growing technology promises to enable multiscale biological research and accelerate translation from microscopic laboratory discoveries to macroscopic clinical practice. PAT may also hold the key to label-free early detection of cancer by in vivo quantification of hypermetabolism, the quintessential hallmark of malignancy. Learning Objectives: To understand the contrast mechanism of PAT To understand the multiscale applications of PAT Benjamin M. W. Tsui: Multi-modality molecular imaging instrumentation and techniques have been major developments in small animal imaging that has contributed significantly

  15. WE-H-206-03: Promises and Challenges of Benchtop X-Ray Fluorescence CT (XFCT) for Quantitative in Vivo Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S. [UT MD Anderson Cancer Center (United States)

    2016-06-15

    Lihong V. Wang: Photoacoustic tomography (PAT), combining non-ionizing optical and ultrasonic waves via the photoacoustic effect, provides in vivo multiscale functional, metabolic, and molecular imaging. Broad applications include imaging of the breast, brain, skin, esophagus, colon, vascular system, and lymphatic system in humans or animals. Light offers rich contrast but does not penetrate biological tissue in straight paths as x-rays do. Consequently, high-resolution pure optical imaging (e.g., confocal microscopy, two-photon microscopy, and optical coherence tomography) is limited to penetration within the optical diffusion limit (∼1 mm in the skin). Ultrasonic imaging, on the contrary, provides fine spatial resolution but suffers from both poor contrast in early-stage tumors and strong speckle artifacts. In PAT, pulsed laser light penetrates tissue and generates a small but rapid temperature rise, which induces emission of ultrasonic waves due to thermoelastic expansion. The ultrasonic waves, orders of magnitude less scattering than optical waves, are then detected to form high-resolution images of optical absorption at depths up to 7 cm, conquering the optical diffusion limit. PAT is the only modality capable of imaging across the length scales of organelles, cells, tissues, and organs (up to whole-body small animals) with consistent contrast. This rapidly growing technology promises to enable multiscale biological research and accelerate translation from microscopic laboratory discoveries to macroscopic clinical practice. PAT may also hold the key to label-free early detection of cancer by in vivo quantification of hypermetabolism, the quintessential hallmark of malignancy. Learning Objectives: To understand the contrast mechanism of PAT To understand the multiscale applications of PAT Benjamin M. W. Tsui: Multi-modality molecular imaging instrumentation and techniques have been major developments in small animal imaging that has contributed significantly

  16. Magnetic resonance spectroscopy as an imaging method

    International Nuclear Information System (INIS)

    Bomsdorf, H.; Imme, M.; Jensen, D.; Kunz, D.; Menhardt, W.; Ottenberg, K.; Roeschmann, P.; Schmidt, K.H.; Tschendel, O.; Wieland, J.

    1990-01-01

    An experimental Magnetic Resonance (MR) system with 4 tesla flux density was set up. For that purpose a data acquisition system and RF coils for resonance frequencies up to 170 MHz were developed. Methods for image guided spectroscopy as well as spectroscopic imaging focussing on the nuclei 1 H and 13 C were developed and tested on volunteers and selected patients. The advantages of the high field strength with respect to spectroscopic studies were demonstrated. Developments of a new fast imaging technique for the acquisition of scout images as well as a method for mapping and displaying the magnetic field inhomogeneity in-vivo represent contributions to the optimisation of the experimental procedure in spectroscopic studies. Investigations on the interaction of RF radiation with the exposed tissue allowed conclusions regarding the applicability of MR methods at high field strengths. Methods for display and processing of multi-dimensional spectroscopic imaging data sets were developed and existing methods for real-time image synthesis were extended. Results achieved in the field of computer aided analysis of MR images comprised new techniques for image background detection, contour detection and automatic image interpretation as well as knowledge bases for textural representation of medical knowledge for diagnosis. (orig.) With 82 refs., 3 tabs., 75 figs [de

  17. A new promising screening method for cognitive functioning in elderly patients

    NARCIS (Netherlands)

    Kuin, Y.; Nijsten, J.M.H.; Stok-Koch, E.G.H.J.; Jansen, R.W.M.M.

    1996-01-01

    The Mini Mental State Examination (MMSE) is frequently used as a screening method to detect cognitive dysfunctioning. However, the MMSE has limited sensitivity to detect mild impairment. We aimed to develop a new screening method to discriminate between normal and mild cognitive functioning in older

  18. Analysis of protein carbonylation - pitfalls and promise in commonly used methods

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, A.; Wojdyla, K.; Nedic, O.

    2014-01-01

    that research scientists are becoming more eager to be able to measure accurately the level of oxidized protein in biological materials, and to determine the precise site of the oxidative attack on the protein, in order to get insights into the molecular mechanisms involved in the progression of diseases....... Several methods for measuring protein carbonylation have been implemented in different laboratories around the world. However, to date no methods prevail as the most accurate, reliable, and robust. The present paper aims at giving an overview of the common methods used to determine protein carbonylation...... in biological material as well as to highlight the limitations and the potential. The ultimate goal is to give quick tips for a rapid decision making when a method has to be selected and taking into consideration the advantage and drawback of the methods....

  19. Analysis of protein carbonylation-pitfalls and promise in commonly used methods

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, Adelina; Wojdyla, K; Nedić, O

    2014-01-01

    that research scientists are becoming more eager to be able to measure accurately the level of oxidized protein in biological materials, and to determine the precise site of the oxidative attack on the protein, in order to get insights into the molecular mechanisms involved in the progression of diseases....... Several methods for measuring protein carbonylation have been implemented in different laboratories around the world. However, to date no methods prevail as the most accurate, reliable, and robust. The present paper aims at giving an overview of the common methods used to determine protein carbonylation...... in biological material as well as to highlight the limitations and the potential. The ultimate goal is to give quick tips for a rapid decision making when a method has to be selected and taking into consideration the advantage and drawback of the methods....

  20. A broken promise: microbiome differential abundance methods do not control the false discovery rate.

    Science.gov (United States)

    Hawinkel, Stijn; Mattiello, Federico; Bijnens, Luc; Thas, Olivier

    2017-08-22

    High-throughput sequencing technologies allow easy characterization of the human microbiome, but the statistical methods to analyze microbiome data are still in their infancy. Differential abundance methods aim at detecting associations between the abundances of bacterial species and subject grouping factors. The results of such methods are important to identify the microbiome as a prognostic or diagnostic biomarker or to demonstrate efficacy of prodrug or antibiotic drugs. Because of a lack of benchmarking studies in the microbiome field, no consensus exists on the performance of the statistical methods. We have compared a large number of popular methods through extensive parametric and nonparametric simulation as well as real data shuffling algorithms. The results are consistent over the different approaches and all point to an alarming excess of false discoveries. This raises great doubts about the reliability of discoveries in past studies and imperils reproducibility of microbiome experiments. To further improve method benchmarking, we introduce a new simulation tool that allows to generate correlated count data following any univariate count distribution; the correlation structure may be inferred from real data. Most simulation studies discard the correlation between species, but our results indicate that this correlation can negatively affect the performance of statistical methods. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Image splitting and remapping method for radiological image compression

    Science.gov (United States)

    Lo, Shih-Chung B.; Shen, Ellen L.; Mun, Seong K.

    1990-07-01

    A new decomposition method using image splitting and gray-level remapping has been proposed for image compression, particularly for images with high contrast resolution. The effects of this method are especially evident in our radiological image compression study. In our experiments, we tested the impact of this decomposition method on image compression by employing it with two coding techniques on a set of clinically used CT images and several laser film digitized chest radiographs. One of the compression techniques used was full-frame bit-allocation in the discrete cosine transform domain, which has been proven to be an effective technique for radiological image compression. The other compression technique used was vector quantization with pruned tree-structured encoding, which through recent research has also been found to produce a low mean-square-error and a high compression ratio. The parameters we used in this study were mean-square-error and the bit rate required for the compressed file. In addition to these parameters, the difference between the original and reconstructed images will be presented so that the specific artifacts generated by both techniques can be discerned by visual perception.

  2. A Promising New Method to Estimate Drug-Polymer Solubility at Room Temperature

    DEFF Research Database (Denmark)

    Knopp, Matthias Manne; Gannon, Natasha; Porsch, Ilona

    2016-01-01

    The established methods to predict drug-polymer solubility at room temperature either rely on extrapolation over a long temperature range or are limited by the availability of a liquid analogue of the polymer. To overcome these issues, this work investigated a new methodology where the drug-polymer...... solubility is estimated from the solubility of the drug in a solution of the polymer at room temperature using the shake-flask method. Thus, the new polymer in solution method does not rely on temperature extrapolations and only requires the polymer and a solvent, in which the polymer is soluble, that does...... not affect the molecular structure of the drug and polymer relative to that in the solid state. Consequently, as this method has the potential to provide fast and precise estimates of drug-polymer solubility at room temperature, we encourage the scientific community to further investigate this principle both...

  3. Method for position emission mammography image reconstruction

    Science.gov (United States)

    Smith, Mark Frederick

    2004-10-12

    An image reconstruction method comprising accepting coincidence datat from either a data file or in real time from a pair of detector heads, culling event data that is outside a desired energy range, optionally saving the desired data for each detector position or for each pair of detector pixels on the two detector heads, and then reconstructing the image either by backprojection image reconstruction or by iterative image reconstruction. In the backprojection image reconstruction mode, rays are traced between centers of lines of response (LOR's), counts are then either allocated by nearest pixel interpolation or allocated by an overlap method and then corrected for geometric effects and attenuation and the data file updated. If the iterative image reconstruction option is selected, one implementation is to compute a grid Siddon retracing, and to perform maximum likelihood expectation maiximization (MLEM) computed by either: a) tracing parallel rays between subpixels on opposite detector heads; or b) tracing rays between randomized endpoint locations on opposite detector heads.

  4. Linear Methods for Image Interpolation

    OpenAIRE

    Pascal Getreuer

    2011-01-01

    We discuss linear methods for interpolation, including nearest neighbor, bilinear, bicubic, splines, and sinc interpolation. We focus on separable interpolation, so most of what is said applies to one-dimensional interpolation as well as N-dimensional separable interpolation.

  5. Fabrication of Mineralized Collagen from Bovine Waste Materials by Hydrothermal Method as Promised Biomaterials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Macossay, Javier

    2011-01-01

    In the present study, we aimed to produce mineralized-collagen by hydrothermal process. A simple method not depending on additional foreign chemicals has been employed to isolate the mineralized-collagen fibers from bovine waste. The process of extraction involves the use of hydrothermal method...... mineral content in the individual fibers. The X-ray diffraction showed the crystalline feature of the obtained nano-compounds. The thermo gravimetric analysis was used to differentiate between the collagen and mineral parts of obtained product. Overall, the results generously indicated production of well...

  6. Large-scale photochemical reactions of nanocrystalline suspensions: a promising green chemistry method.

    Science.gov (United States)

    Veerman, Marcel; Resendiz, Marino J E; Garcia-Garibay, Miguel A

    2006-06-08

    Photochemical reactions in the solid state can be scaled up from a few milligrams to 10 grams by using colloidal suspensions of a photoactive molecular crystal prepared by the solvent shift method. Pure products are recovered by filtration, and the use of H(2)O as a suspension medium makes this method a very attractive one from a green chemistry perspective. Using the photodecarbonylation of dicumyl ketone (DCK) as a test system, we show that reaction efficiencies in colloidal suspensions rival those observed in solution. [reaction: see text

  7. Digital image envelope: method and evaluation

    Science.gov (United States)

    Huang, H. K.; Cao, Fei; Zhou, Michael Z.; Mogel, Greg T.; Liu, Brent J.; Zhou, Xiaoqiang

    2003-05-01

    Health data security, characterized in terms of data privacy, authenticity, and integrity, is a vital issue when digital images and other patient information are transmitted through public networks in telehealth applications such as teleradiology. Mandates for ensuring health data security have been extensively discussed (for example The Health Insurance Portability and Accountability Act, HIPAA) and health informatics guidelines (such as the DICOM standard) are beginning to focus on issues of data continue to be published by organizing bodies in healthcare; however, there has not been a systematic method developed to ensure data security in medical imaging Because data privacy and authenticity are often managed primarily with firewall and password protection, we have focused our research and development on data integrity. We have developed a systematic method of ensuring medical image data integrity across public networks using the concept of the digital envelope. When a medical image is generated regardless of the modality, three processes are performed: the image signature is obtained, the DICOM image header is encrypted, and a digital envelope is formed by combining the signature and the encrypted header. The envelope is encrypted and embedded in the original image. This assures the security of both the image and the patient ID. The embedded image is encrypted again and transmitted across the network. The reverse process is performed at the receiving site. The result is two digital signatures, one from the original image before transmission, and second from the image after transmission. If the signatures are identical, there has been no alteration of the image. This paper concentrates in the method and evaluation of the digital image envelope.

  8. Soil Scientific Research Methods Used in Archaeology – Promising Soil Biochemistry: a Mini-review

    Directory of Open Access Journals (Sweden)

    Valerie Vranová

    2015-01-01

    Full Text Available This work seeks to review soil scientific methods that have been used and are still being used in archaeology. This review paper aims at emphasising the importance of soil science practice to archaeology thus adding a scientific analytical nature to the cultural nature of archaeology. Common methods (physical, chemical and biochemical used to analyse archaeological soils and artefacts is touched on and their strengths and shortcomings duly noted to become the base for future research. Furthermore, the authors made emphasis on distinctive excavating/sampling methods, biochemical analyses focused on distinctive features of plough-land and soil organic matter mineralization, Counter Immunoelectrophoresis (CEIP method by the presence of proteins testing, carbon analyses such as carbon-14 dating techniques, soil phosphorus studies and geochemical analyses of hematite Fe2O3 and cinnabaryte HgS contents. It is obvious that, the future of archaeology is in the soil because the soil harbours information of the past hence the synergy between soil and archaeological research has to be strengthened and archaeology made a prime agenda by soil scientists by expanding the analyses scope of total phosphorus extraction and giving attention to soil magnetism.

  9. SAAS: Short Amino Acid Sequence - A Promising Protein Secondary Structure Prediction Method of Single Sequence

    Directory of Open Access Journals (Sweden)

    Zhou Yuan Wu

    2013-07-01

    Full Text Available In statistical methods of predicting protein secondary structure, many researchers focus on single amino acid frequencies in α-helices, β-sheets, and so on, or the impact near amino acids on an amino acid forming a secondary structure. But the paper considers a short sequence of amino acids (3, 4, 5 or 6 amino acids as integer, and statistics short sequence's probability forming secondary structure. Also, many researchers select low homologous sequences as statistical database. But this paper select whole PDB database. In this paper we propose a strategy to predict protein secondary structure using simple statistical method. Numerical computation shows that, short amino acids sequence as integer to statistics, which can easy see trend of short sequence forming secondary structure, and it will work well to select large statistical database (whole PDB database without considering homologous, and Q3 accuracy is ca. 74% using this paper proposed simple statistical method, but accuracy of others statistical methods is less than 70%.

  10. Concept mapping as a promising method to bring practice into science

    NARCIS (Netherlands)

    van Bon, M.J.H.; van de Goor, L.A.M.; Holsappel, J.C.; Kuunders, T.J.M.; Jacobs-van der Bruggen, M.A.M.; te Brake, J.H.M.; van Oers, J.A.M.

    2014-01-01

    Objective Concept mapping is a method for developing a conceptual framework of a complex topic for use as a guide to evaluation or planning. In concept mapping, thoughts and ideas are represented in the form of a picture or map, the content of which is determined by a group of stakeholders. This

  11. On an image reconstruction method for ECT

    Science.gov (United States)

    Sasamoto, Akira; Suzuki, Takayuki; Nishimura, Yoshihiro

    2007-04-01

    An image by Eddy Current Testing(ECT) is a blurred image to original flaw shape. In order to reconstruct fine flaw image, a new image reconstruction method has been proposed. This method is based on an assumption that a very simple relationship between measured data and source were described by a convolution of response function and flaw shape. This assumption leads to a simple inverse analysis method with deconvolution.In this method, Point Spread Function (PSF) and Line Spread Function(LSF) play a key role in deconvolution processing. This study proposes a simple data processing to determine PSF and LSF from ECT data of machined hole and line flaw. In order to verify its validity, ECT data for SUS316 plate(200x200x10mm) with artificial machined hole and notch flaw had been acquired by differential coil type sensors(produced by ZETEC Inc). Those data were analyzed by the proposed method. The proposed method restored sharp discrete multiple hole image from interfered data by multiple holes. Also the estimated width of line flaw has been much improved compared with original experimental data. Although proposed inverse analysis strategy is simple and easy to implement, its validity to holes and line flaw have been shown by many results that much finer image than original image have been reconstructed.

  12. 99mTc-Hynic-minigastrin 1: a promising radiopharmaceutical for imaging gastrin/CCK-positive tumors: preclinical evaluation

    International Nuclear Information System (INIS)

    Guggenberg, E. von; Decristoforo, C.; Behe, M.; Behr, T.

    2002-01-01

    Full text: Gastrin/CCK receptors are over expressed in a number of tumors such as MW and SCLC. Therefore gastrin analogues binding to the CCK-B receptor are. promising peptides for Nuclear Medicine imaging. Recently minigastrin 1 has been labeled with 131 I, 111 In and 90 Y (Behr et al 1999). HYNIC as bifunctional chelator has shown favorable properties for 99m Tc-labeling of small peptides. The aim of this study was the preparation, 99m Tc-labeling and evaluation in vitro and in vivo of HYNIC-minigastrin 1. HYNIC-minigastrin 1 was prepared by coupling protected HYNIC to minigastrin immobilized on a resin, followed by TFA cleavage and HPLC purification. The peptide was characterized by RP-HPLC and MS. 99m Tc-labeling was performed using different coligands, such as tricine, EDDA, tricine ternary ligand systems. In vitro stability was tested in plasma and towards cystein, plasma protein binding was determined. Receptor binding assays using a CCK-B receptor positive cellline (AR42J) were performed and biodistribution in normal Wistar rats was studied with a gamma camera followed by dissection. At specific activities >1 Ci/μmol HYNIC-minigastrin 1 could be labeled with yields >95 % only using tricine as coligand. Other coligands or addition of a ternary ligand failed to give reasonable labeling yields. Two isomers of 99m Tc-tricine-HYNIC-minigastrin 1 were observed. At higher temperature quantitative yields of a stable isomer with high hydrophilicity, low protein binding and low intestinal excretion in rat biodistribution studies was obtained. Overall biodistribution in rats was similar to 111 In-DTPA-minigastrin 1 with rapid renal excretion and high kidney retention. 99m Tc-Tricine-HYNIC-minigastrin could be displaced by unlabelled Minigastrin from AR4-2J cell-membranes. A gastrin derivative could be labeled at high specific activities with 99m Tc showing isomerism dependent on labeling conditions. 99m Tc-labelled HYNIC-minigastrin 1 shows promising in vitro and in

  13. Troubling objectivity: the promises and pitfalls of training Haitian clinicians in qualitative research methods.H.

    Science.gov (United States)

    Minn, Pierre

    2015-01-01

    Building research capacity is a central component of many contemporary global health programs and partnerships. While medical anthropologists have been conducting qualitative research in resource-poor settings for decades, they are increasingly called on to train "local" clinicians, researchers, and students in qualitative research methods. In this article, I describe the process of teaching introductory courses in qualitative research methods to Haitian clinicians, hospital staff, and medical students, who rarely encounter qualitative research in their training or practice. These trainings allow participants to identify and begin to address challenges related to health services delivery, quality of care, and provider-patient relations. However, they also run the risk of perpetuating colonial legacies of objectification and reinforcing hierarchies of knowledge and knowledge production. As these trainings increase in number and scope, they offer the opportunity to reflect critically on new forms of transnational interventions that aim to reduce health disparities.

  14. Promising ethical arguments for product differentiation in the organic food sector. A mixed methods research approach

    OpenAIRE

    Zander, Katrin; Stolz, Hanna; Hamm, Ulrich

    2013-01-01

    Ethical consumerism is a growing trend worldwide. Ethical consumers’ expectations are increasing and neither the Fairtrade nor the organic farming concept covers all the ethical concerns of consumers. Against this background the aim of this research is to elicit consumers’ preferences regarding organic food with additional ethical attributes and their relevance at the market place. A mixed methods research approach was applied by combining an Information Display Matrix, Focus Group Discuss...

  15. Method for nuclear magnetic resonance imaging

    Science.gov (United States)

    Kehayias, J.J.; Joel, D.D.; Adams, W.H.; Stein, H.L.

    1988-05-26

    A method for in vivo NMR imaging of the blood vessels and organs of a patient characterized by using a dark dye-like imaging substance consisting essentially of a stable, high-purity concentration of D/sub 2/O in a solution with water.

  16. Linear Methods for Image Interpolation

    Directory of Open Access Journals (Sweden)

    Pascal Getreuer

    2011-09-01

    Full Text Available We discuss linear methods for interpolation, including nearest neighbor, bilinear, bicubic, splines, and sinc interpolation. We focus on separable interpolation, so most of what is said applies to one-dimensional interpolation as well as N-dimensional separable interpolation.

  17. Promising ethical arguments for product differentiation in the organic food sector. A mixed methods research approach.

    Science.gov (United States)

    Zander, Katrin; Stolz, Hanna; Hamm, Ulrich

    2013-03-01

    Ethical consumerism is a growing trend worldwide. Ethical consumers' expectations are increasing and neither the Fairtrade nor the organic farming concept covers all the ethical concerns of consumers. Against this background the aim of this research is to elicit consumers' preferences regarding organic food with additional ethical attributes and their relevance at the market place. A mixed methods research approach was applied by combining an Information Display Matrix, Focus Group Discussions and Choice Experiments in five European countries. According to the results of the Information Display Matrix, 'higher animal welfare', 'local production' and 'fair producer prices' were preferred in all countries. These three attributes were discussed with Focus Groups in depth, using rather emotive ways of labelling. While the ranking of the attributes was the same, the emotive way of communicating these attributes was, for the most part, disliked by participants. The same attributes were then used in Choice Experiments, but with completely revised communication arguments. According to the results of the Focus Groups, the arguments were presented in a factual manner, using short and concise statements. In this research step, consumers in all countries except Austria gave priority to 'local production'. 'Higher animal welfare' and 'fair producer prices' turned out to be relevant for buying decisions only in Germany and Switzerland. According to our results, there is substantial potential for product differentiation in the organic sector through making use of production standards that exceed existing minimum regulations. The combination of different research methods in a mixed methods approach proved to be very helpful. The results of earlier research steps provided the basis from which to learn - findings could be applied in subsequent steps, and used to adjust and deepen the research design. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Imaging methods in medical diagnosis

    International Nuclear Information System (INIS)

    Krestel, E.

    1981-01-01

    Pictures of parts of the human body or of the human body (views, superposition pictures, pictures of body layers, or photographs) are considerable helps for the medical diagnostics. Physics, electrotechnique, and machine construction make the picture production possible. Modern electronics and optics offer facilities of picture processing which influences the picture quality. Picture interpretation is the the physican's task. The picture-delivering methods applied in medicine include the conventional X-ray diagnostics, X-ray computer tomography, nuclear diagnostics, sonography with ultas sound, and endoscopy. Their rapid development and immprovement was caused by the development of electronics during the past 20 years. A method presently in discussion and development is the Kernspin-tomography. (orig./MG) [de

  19. A NEW IMAGE REGISTRATION METHOD FOR GREY IMAGES

    Institute of Scientific and Technical Information of China (English)

    Nie Xuan; Zhao Rongchun; Jiang Zetao

    2004-01-01

    The proposed algorithm relies on a group of new formulas for calculating tangent slope so as to address angle feature of edge curves of image. It can utilize tangent angle features to estimate automatically and fully the rotation parameters of geometric transform and enable rough matching of images with huge rotation difference. After angle compensation, it can search for matching point sets by correlation criterion, then calculate parameters of affine transform, enable higher-precision emendation of rotation and transferring. Finally, it fulfills precise matching for images with relax-tense iteration method. Compared with the registration approach based on wavelet direction-angle features, the matching algorithm with tangent feature of image edge is more robust and realizes precise registration of various images. Furthermore, it is also helpful in graphics matching.

  20. Lactic Acid Fermentation, Urea and Lime Addition: Promising Faecal Sludge Sanitizing Methods for Emergency Sanitation.

    Science.gov (United States)

    Anderson, Catherine; Malambo, Dennis Hanjalika; Perez, Maria Eliette Gonzalez; Nobela, Happiness Ngwanamoseka; de Pooter, Lobke; Spit, Jan; Hooijmans, Christine Maria; de Vossenberg, Jack van; Greya, Wilson; Thole, Bernard; van Lier, Jules B; Brdjanovic, Damir

    2015-10-29

    In this research, three faecal sludge sanitizing methods-lactic acid fermentation, urea treatment and lime treatment-were studied for application in emergency situations. These methods were investigated by undertaking small scale field trials with pit latrine sludge in Blantyre, Malawi. Hydrated lime was able to reduce the E. coli count in the sludge to below the detectable limit within 1 h applying a pH > 11 (using a dosage from 7% to 17% w/w, depending faecal sludge alkalinity), urea treatment required about 4 days using 2.5% wet weight urea addition, and lactic acid fermentation needed approximately 1 week after being dosed with 10% wet weight molasses (2 g (glucose/fructose)/kg) and 10% wet weight pre-culture (99.8% pasteurised whole milk and 0.02% fermented milk drink containing Lactobacillus casei Shirota). Based on Malawian prices, the cost of sanitizing 1 m³ of faecal sludge was estimated to be €32 for lactic acid fermentation, €20 for urea treatment and €12 for hydrated lime treatment.

  1. Spatial capture-recapture: a promising method for analyzing data collected using artificial cover objects

    Science.gov (United States)

    Sutherland, Chris; Munoz, David; Miller, David A.W.; Grant, Evan H. Campbell

    2016-01-01

    Spatial capture–recapture (SCR) is a relatively recent development in ecological statistics that provides a spatial context for estimating abundance and space use patterns, and improves inference about absolute population density. SCR has been applied to individual encounter data collected noninvasively using methods such as camera traps, hair snares, and scat surveys. Despite the widespread use of capture-based surveys to monitor amphibians and reptiles, there are few applications of SCR in the herpetological literature. We demonstrate the utility of the application of SCR for studies of reptiles and amphibians by analyzing capture–recapture data from Red-Backed Salamanders, Plethodon cinereus, collected using artificial cover boards. Using SCR to analyze spatial encounter histories of marked individuals, we found evidence that density differed little among four sites within the same forest (on average, 1.59 salamanders/m2) and that salamander detection probability peaked in early October (Julian day 278) reflecting expected surface activity patterns of the species. The spatial scale of detectability, a measure of space use, indicates that the home range size for this population of Red-Backed Salamanders in autumn was 16.89 m2. Surveying reptiles and amphibians using artificial cover boards regularly generates spatial encounter history data of known individuals, which can readily be analyzed using SCR methods, providing estimates of absolute density and inference about the spatial scale of habitat use.

  2. Chemical vapour deposition - a promising method for production of different kinds of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt, A.; Ritschel, M.; Bartsch, K.; Graff, A.; Taeschner, C.; Fink, J. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany)

    2001-08-01

    Carbon nanostructures (fibres, multi and single walled tubes) have been synthesized by catalytic chemical vapour deposition. The catalyst material, deposition temperature and the used hydrocarbon are the main parameters responsible for the formation of the desired structure. In dependence on these parameters and by optimising the deposition process nanofibres with herringbone structure and tubular multiwalled nanotubes were deposited in large amounts and high purity. In the case of single wall nanotubes synthesis an aftertreatment and process is absolutely necessary to obtain material with high percentage of tubes. Layers of disordered and aligned multiwalled nanotubes were deposited on oxidised silicon substrates coated with thin sputtered metal layers (Co, permalloy) by using the micro-wave assisted plasma CVD process or the bias supported hot filament CVD method. The latter method allows relatively low deposition temperatures (550 - 750 C). The obtained carbon modifications were characterised by scanning and transmission electron microscopy. Furthermore, the electron field emission of the CNT's layers were investigated. (orig.)

  3. TH-C-BRF-01: The Promise and Potential Pitfalls of Deformable Image Registration in Clinical Practice

    International Nuclear Information System (INIS)

    Brock, K; Oldham, M; Cai, J; Pouliot, J

    2014-01-01

    Accurate and robust deformable image registration (DIR) is a key enabling technique in the clinical realization of two approaches for advancing radiation therapy treatment efficacy: adaptive radiation therapy and treatment response assessment. Currently there are a wide variety of DIR methods including the categories of splines, optical/diffusion, free-form, and biomechanical algorithms. All methods aim to translate information between image sets (including multi-modal data) in the presence of spatial deformation of tissues. However, recent research has shown that different DIR algorithms can yield substantially different results for the same reference deformation, and that DIR performance can be site and application dependent. As a result, errors can occur, and subsequent patient treatment can be compromised. There is a clear need for greater understanding of appropriate use of DIR techniques, as well as effective methods of validation, evaluation, and improvement. In this session, we will review the state-of-the-art concerning DIR development, clinical application, and performance evaluation. Novel DIR methods and evaluating technologies will be reviewed. Learning Objectives: To understand the underlying principles and physics of current DIR techniques To explore potential clinical applications and areas of high impact for DIR To investigate sources of uncertainty, appropriate usage, and methods for validating and evaluating DIR performance

  4. Historic Methods for Capturing Magnetic Field Images

    Science.gov (United States)

    Kwan, Alistair

    2016-01-01

    I investigated two late 19th-century methods for capturing magnetic field images from iron filings for historical insight into the pedagogy of hands-on physics education methods, and to flesh out teaching and learning practicalities tacit in the historical record. Both methods offer opportunities for close sensory engagement in data-collection…

  5. Methods for evaluating imaging methods of limited reproducibility

    International Nuclear Information System (INIS)

    Krummenauer, F.

    2005-01-01

    Just like new drugs, new or modified imaging methods must be subjected to objective clinical tests, including tests on humans. In this, it must be ensured that the principle of Good Clinical Practice (GCP) are followed with regard to medical, administrative and methodical quality. Innovative methods fo clinical epidemiology and medical biometry should be applied from the planning stage to the final statistical evaluation. The author presents established and new methods for planning, evaluation and reporting of clinical tests of diagnostic methods, and especially imaging methods, in clinical medicine and illustrates these by means of current research projects in the various medical disciplines. The strategies presented are summarized in a recommendation based on the concept of phases I - IV of clinical drug testing in order to enable standardisation of the clinical evaluation of imaging methods. (orig.)

  6. Fuzzy promises

    DEFF Research Database (Denmark)

    Anker, Thomas Boysen; Kappel, Klemens; Eadie, Douglas

    2012-01-01

    as narrative material to communicate self-identity. Finally, (c) we propose that brands deliver fuzzy experiential promises through effectively motivating consumers to adopt and play a social role implicitly suggested and facilitated by the brand. A promise is an inherently ethical concept and the article...... concludes with an in-depth discussion of fuzzy brand promises as two-way ethical commitments that put requirements on both brands and consumers....

  7. Ultrasonic Nebulizer Assisted LIBS: a Promising Metal Elements Detection Method for Aqueous Sample Analysis

    International Nuclear Information System (INIS)

    Zhong Shilei; Zheng Ronger; Lu Yuan; Cheng Kai; Xiu Junshan

    2015-01-01

    A newly developed approach for trace metal elements detection for aqueous samples analysis is presented in this paper. The idea of this approach is to improve ablation efficiency by transforming the liquid sample into a dense cloud of droplets using an ultrasonic nebulizer. The resulting droplets are then subjected to analysis by laser induced breakdown spectroscopy (LIBS). A purpose-built ultrasonic nebulizer assisted LIBS (UN-LIBS) system has been applied to the analysis of aqueous samples at trace levels of concentration. Experimental investigations of solution samples were carried out with various dissolved trace metal elements (Mn, Zn, Cu, Pb, Fe, Mg and Na) using this approach. The characteristics of UN-LIBS signal of the elements were investigated regarding the lifetime and S/B ratio and the calibration curves for trace metal elements analyses. The obtained LODs are comparable or much better than the LODS of the reported signal enhancement approaches when the laser pulse energy was as low as 30 mJ. The good linearity of calibration curves and the low LODs shows the potential ability of this method for metal elements analysis application. The density of the electrons was calculated by measuring the Stark width of the line of H α . The possible mechanism of the LIBS signal enhancement of this approach was briefly discussed. (paper)

  8. Matrix Krylov subspace methods for image restoration

    Directory of Open Access Journals (Sweden)

    khalide jbilou

    2015-09-01

    Full Text Available In the present paper, we consider some matrix Krylov subspace methods for solving ill-posed linear matrix equations and in those problems coming from the restoration of blurred and noisy images. Applying the well known Tikhonov regularization procedure leads to a Sylvester matrix equation depending the Tikhonov regularized parameter. We apply the matrix versions of the well known Krylov subspace methods, namely the Least Squared (LSQR and the conjugate gradient (CG methods to get approximate solutions representing the restored images. Some numerical tests are presented to show the effectiveness of the proposed methods.

  9. Diagnosing developmental dyscalculia on the basis of reliable single case FMRI methods: promises and limitations.

    Directory of Open Access Journals (Sweden)

    Philipp Johannes Dinkel

    representation in fronto-parietal cortex. We conclude that dyscalculic children show large individual differences in brain activation patterns. Nonetheless, the majority of dyscalculic children can be differentiated from controls employing brain activation patterns when appropriate methods are used.

  10. Diagnosing developmental dyscalculia on the basis of reliable single case FMRI methods: promises and limitations.

    Science.gov (United States)

    Dinkel, Philipp Johannes; Willmes, Klaus; Krinzinger, Helga; Konrad, Kerstin; Koten, Jan Willem

    2013-01-01

    fronto-parietal cortex. We conclude that dyscalculic children show large individual differences in brain activation patterns. Nonetheless, the majority of dyscalculic children can be differentiated from controls employing brain activation patterns when appropriate methods are used.

  11. Analysis of Non Local Image Denoising Methods

    Science.gov (United States)

    Pardo, Álvaro

    Image denoising is probably one of the most studied problems in the image processing community. Recently a new paradigm on non local denoising was introduced. The Non Local Means method proposed by Buades, Morel and Coll attracted the attention of other researches who proposed improvements and modifications to their proposal. In this work we analyze those methods trying to understand their properties while connecting them to segmentation based on spectral graph properties. We also propose some improvements to automatically estimate the parameters used on these methods.

  12. Handbook of mathematical methods in imaging

    CERN Document Server

    2015-01-01

    The Handbook of Mathematical Methods in Imaging provides a comprehensive treatment of the mathematical techniques used in imaging science. The material is grouped into two central themes, namely, Inverse Problems (Algorithmic Reconstruction) and Signal and Image Processing. Each section within the themes covers applications (modeling), mathematics, numerical methods (using a case example) and open questions. Written by experts in the area, the presentation is mathematically rigorous. This expanded and revised second edition contains updates to existing chapters and 16 additional entries on important mathematical methods such as graph cuts, morphology, discrete geometry, PDEs, conformal methods, to name a few. The entries are cross-referenced for easy navigation through connected topics. Available in both print and electronic forms, the handbook is enhanced by more than 200 illustrations and an extended bibliography. It will benefit students, scientists and researchers in applied mathematics. Engineers and com...

  13. Accelerated gradient methods for constrained image deblurring

    International Nuclear Information System (INIS)

    Bonettini, S; Zanella, R; Zanni, L; Bertero, M

    2008-01-01

    In this paper we propose a special gradient projection method for the image deblurring problem, in the framework of the maximum likelihood approach. We present the method in a very general form and we give convergence results under standard assumptions. Then we consider the deblurring problem and the generality of the proposed algorithm allows us to add a energy conservation constraint to the maximum likelihood problem. In order to improve the convergence rate, we devise appropriate scaling strategies and steplength updating rules, especially designed for this application. The effectiveness of the method is evaluated by means of a computational study on astronomical images corrupted by Poisson noise. Comparisons with standard methods for image restoration, such as the expectation maximization algorithm, are also reported.

  14. Image change detection systems, methods, and articles of manufacture

    Science.gov (United States)

    Jones, James L.; Lassahn, Gordon D.; Lancaster, Gregory D.

    2010-01-05

    Aspects of the invention relate to image change detection systems, methods, and articles of manufacture. According to one aspect, a method of identifying differences between a plurality of images is described. The method includes loading a source image and a target image into memory of a computer, constructing source and target edge images from the source and target images to enable processing of multiband images, displaying the source and target images on a display device of the computer, aligning the source and target edge images, switching displaying of the source image and the target image on the display device, to enable identification of differences between the source image and the target image.

  15. Quality assessment in radiological imaging methods

    International Nuclear Information System (INIS)

    Herstel, W.

    1985-01-01

    The equipment used in diagnostic radiology is becoming more and more complicated. In the imaging process four components are distinguished, each of which can introduce loss in essential information: the X-ray source, the human body, the imaging system and the observer. In nearly all imaging methods the X-ray quantum fluctuations are a limitation to observation. But there are also technical factors. As an illustration it is shown how in a television scanning process the resolution is restricted by the system parameters. A short review is given of test devices and the results are given of an image comparison based on regular bar patterns. Although this method has the disadvantage of measuring mainly the limiting resolution, the results of the test correlate reasonably well with the subjective appreciations of radiographs of bony structures made by a group of trained radiologists. Fluoroscopic systems should preferably be tested using moving structures under dynamic conditions. (author)

  16. Circular SAR Optimization Imaging Method of Buildings

    Directory of Open Access Journals (Sweden)

    Wang Jian-feng

    2015-12-01

    Full Text Available The Circular Synthetic Aperture Radar (CSAR can obtain the entire scattering properties of targets because of its great ability of 360° observation. In this study, an optimal orientation of the CSAR imaging algorithm of buildings is proposed by applying a combination of coherent and incoherent processing techniques. FEKO software is used to construct the electromagnetic scattering modes and simulate the radar echo. The FEKO imaging results are compared with the isotropic scattering results. On comparison, the optimal azimuth coherent accumulation angle of CSAR imaging of buildings is obtained. Practically, the scattering directions of buildings are unknown; therefore, we divide the 360° echo of CSAR into many overlapped and few angle echoes corresponding to the sub-aperture and then perform an imaging procedure on each sub-aperture. Sub-aperture imaging results are applied to obtain the all-around image using incoherent fusion techniques. The polarimetry decomposition method is used to decompose the all-around image and further retrieve the edge information of buildings successfully. The proposed method is validated with P-band airborne CSAR data from Sichuan, China.

  17. Method of orthogonally splitting imaging pose measurement

    Science.gov (United States)

    Zhao, Na; Sun, Changku; Wang, Peng; Yang, Qian; Liu, Xintong

    2018-01-01

    In order to meet the aviation's and machinery manufacturing's pose measurement need of high precision, fast speed and wide measurement range, and to resolve the contradiction between measurement range and resolution of vision sensor, this paper proposes an orthogonally splitting imaging pose measurement method. This paper designs and realizes an orthogonally splitting imaging vision sensor and establishes a pose measurement system. The vision sensor consists of one imaging lens, a beam splitter prism, cylindrical lenses and dual linear CCD. Dual linear CCD respectively acquire one dimensional image coordinate data of the target point, and two data can restore the two dimensional image coordinates of the target point. According to the characteristics of imaging system, this paper establishes the nonlinear distortion model to correct distortion. Based on cross ratio invariability, polynomial equation is established and solved by the least square fitting method. After completing distortion correction, this paper establishes the measurement mathematical model of vision sensor, and determines intrinsic parameters to calibrate. An array of feature points for calibration is built by placing a planar target in any different positions for a few times. An terative optimization method is presented to solve the parameters of model. The experimental results show that the field angle is 52 °, the focus distance is 27.40 mm, image resolution is 5185×5117 pixels, displacement measurement error is less than 0.1mm, and rotation angle measurement error is less than 0.15°. The method of orthogonally splitting imaging pose measurement can satisfy the pose measurement requirement of high precision, fast speed and wide measurement range.

  18. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    S. A. Seyyedi

    2013-01-01

    Full Text Available Steganography is a method of hiding information in other information of different format (container. There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  19. Study on Processing Method of Image Shadow

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2014-07-01

    Full Text Available In order to effectively remove disturbance of shadow and enhance robustness of information processing of computer visual image, this paper makes study on inspection and removal of image shadow. It makes study the continual removal algorithm of shadow based on integration, the illumination surface and texture, it respectively introduces their work principles and realization method, it can effectively carrying processing for shadow by test.

  20. Coherent diffractive imaging methods for semiconductor manufacturing

    Science.gov (United States)

    Helfenstein, Patrick; Mochi, Iacopo; Rajeev, Rajendran; Fernandez, Sara; Ekinci, Yasin

    2017-12-01

    The paradigm shift of the semiconductor industry moving from deep ultraviolet to extreme ultraviolet lithography (EUVL) brought about new challenges in the fabrication of illumination and projection optics, which constitute one of the core sources of cost of ownership for many of the metrology tools needed in the lithography process. For this reason, lensless imaging techniques based on coherent diffractive imaging started to raise interest in the EUVL community. This paper presents an overview of currently on-going research endeavors that use a number of methods based on lensless imaging with coherent light.

  1. Improved image alignment method in application to X-ray images and biological images.

    Science.gov (United States)

    Wang, Ching-Wei; Chen, Hsiang-Chou

    2013-08-01

    Alignment of medical images is a vital component of a large number of applications throughout the clinical track of events; not only within clinical diagnostic settings, but prominently so in the area of planning, consummation and evaluation of surgical and radiotherapeutical procedures. However, image registration of medical images is challenging because of variations on data appearance, imaging artifacts and complex data deformation problems. Hence, the aim of this study is to develop a robust image alignment method for medical images. An improved image registration method is proposed, and the method is evaluated with two types of medical data, including biological microscopic tissue images and dental X-ray images and compared with five state-of-the-art image registration techniques. The experimental results show that the presented method consistently performs well on both types of medical images, achieving 88.44 and 88.93% averaged registration accuracies for biological tissue images and X-ray images, respectively, and outperforms the benchmark methods. Based on the Tukey's honestly significant difference test and Fisher's least square difference test tests, the presented method performs significantly better than all existing methods (P ≤ 0.001) for tissue image alignment, and for the X-ray image registration, the proposed method performs significantly better than the two benchmark b-spline approaches (P < 0.001). The software implementation of the presented method and the data used in this study are made publicly available for scientific communities to use (http://www-o.ntust.edu.tw/∼cweiwang/ImprovedImageRegistration/). cweiwang@mail.ntust.edu.tw.

  2. An Improved Image Contrast Assessment Method

    Directory of Open Access Journals (Sweden)

    Yuanyuan Fan

    2013-07-01

    Full Text Available Contrast is an important factor affecting the image quality. In order to overcome the problems of local band-limited contrast, a novel image contrast assessment method based on the property of HVS is proposed. Firstly, the image by low-pass filter is performed fast wavelet decomposition. Secondly, all levels of band-pass filtered image and its corresponding low-pass filtered image are obtained by processing wavelet coefficients. Thirdly, local band-limited contrast is calculated, and the local band-limited contrast entropy is calculated according to the definition of entropy, Finally, the contrast entropy of image is obtained by averaging the local band-limited contrast entropy weighed using CSF coefficient. The experiment results show that the best contrast image can be accurately identified in the sequence images obtained by adjusting the exposure time and stretching gray respectively, the assessment results accord with human visual characteristics and make up the lack of local band-limited contrast.

  3. NMR blood vessel imaging method and apparatus

    International Nuclear Information System (INIS)

    Riederer, S.J.

    1988-01-01

    A high speed method of forming computed images of blood vessels based on measurements of characteristics of a body is described comprising the steps of: subjecting a predetermined body area containing blood vessels of interest to, successively, applications of a short repetition time (TR) NMR pulse sequence during the period of high blood velocity and then to corresponding applications during the period of low blood velocity for successive heart beat cycles; weighting the collected imaging data from each application of the NMR pulse sequence according to whether the data was acquired during the period of high blood velocity or a period of low blood velocity of the corresponding heart beat cycle; accumulating weighted imaging data from a plurality of NMR pulse sequences corresponding to high blood velocity periods and from a plurality of NMR pulse sequences corresponding to low blood velocity periods; subtracting the weighted imaging data corresponding to each specific phase encoding acquired during the high blood velocity periods from the weighted imaging data for the same phase encoding corresponding to low blood velocity periods in order to compute blood vessel imaging data; and forming an image of the blood vessels of interest from the blood vessel imaging data

  4. Medical Imaging Image Quality Assessment with Monte Carlo Methods

    International Nuclear Information System (INIS)

    Michail, C M; Fountos, G P; Kalyvas, N I; Valais, I G; Kandarakis, I S; Karpetas, G E; Martini, Niki; Koukou, Vaia

    2015-01-01

    The aim of the present study was to assess image quality of PET scanners through a thin layer chromatography (TLC) plane source. The source was simulated using a previously validated Monte Carlo model. The model was developed by using the GATE MC package and reconstructed images obtained with the STIR software for tomographic image reconstruction, with cluster computing. The PET scanner simulated in this study was the GE DiscoveryST. A plane source consisted of a TLC plate, was simulated by a layer of silica gel on aluminum (Al) foil substrates, immersed in 18F-FDG bath solution (1MBq). Image quality was assessed in terms of the Modulation Transfer Function (MTF). MTF curves were estimated from transverse reconstructed images of the plane source. Images were reconstructed by the maximum likelihood estimation (MLE)-OSMAPOSL algorithm. OSMAPOSL reconstruction was assessed by using various subsets (3 to 21) and iterations (1 to 20), as well as by using various beta (hyper) parameter values. MTF values were found to increase up to the 12th iteration whereas remain almost constant thereafter. MTF improves by using lower beta values. The simulated PET evaluation method based on the TLC plane source can be also useful in research for the further development of PET and SPECT scanners though GATE simulations. (paper)

  5. Development of Quantification Method for Bioluminescence Imaging

    International Nuclear Information System (INIS)

    Kim, Hyeon Sik; Min, Jung Joon; Lee, Byeong Il; Choi, Eun Seo; Tak, Yoon O; Choi, Heung Kook; Lee, Ju Young

    2009-01-01

    Optical molecular luminescence imaging is widely used for detection and imaging of bio-photons emitted by luminescent luciferase activation. The measured photons in this method provide the degree of molecular alteration or cell numbers with the advantage of high signal-to-noise ratio. To extract useful information from the measured results, the analysis based on a proper quantification method is necessary. In this research, we propose a quantification method presenting linear response of measured light signal to measurement time. We detected the luminescence signal by using lab-made optical imaging equipment of animal light imaging system (ALIS) and different two kinds of light sources. One is three bacterial light-emitting sources containing different number of bacteria. The other is three different non-bacterial light sources emitting very weak light. By using the concept of the candela and the flux, we could derive simplified linear quantification formula. After experimentally measuring light intensity, the data was processed with the proposed quantification function. We could obtain linear response of photon counts to measurement time by applying the pre-determined quantification function. The ratio of the re-calculated photon counts and measurement time present a constant value although different light source was applied. The quantification function for linear response could be applicable to the standard quantification process. The proposed method could be used for the exact quantitative analysis in various light imaging equipment with presenting linear response behavior of constant light emitting sources to measurement time

  6. Automatic intra-modality brain image registration method

    International Nuclear Information System (INIS)

    Whitaker, J.M.; Ardekani, B.A.; Braun, M.

    1996-01-01

    Full text: Registration of 3D images of brain of the same or different subjects has potential importance in clinical diagnosis, treatment planning and neurological research. The broad aim of our work is to produce an automatic and robust intra-modality, brain image registration algorithm for intra-subject and inter-subject studies. Our algorithm is composed of two stages. Initial alignment is achieved by finding the values of nine transformation parameters (representing translation, rotation and scale) that minimise the nonoverlapping regions of the head. This is achieved by minimisation of the sum of the exclusive OR of two binary head images, produced using the head extraction procedure described by Ardekani et al. (J Comput Assist Tomogr, 19:613-623, 1995). The initial alignment successfully determines the scale parameters and gross translation and rotation parameters. Fine alignment uses an objective function described for inter-modality registration in Ardekani et al. (ibid.). The algorithm segments one of the images to be aligned into a set of connected components using K-means clustering. Registration is achieved by minimising the K-means variance of the segmentation induced in the other image. Similarity of images of the same modality makes the method attractive for intra-modality registration. A 3D MR image, with voxel dimensions, 2x2x6 mm, was misaligned. The registered image shows visually accurate registration. The average displacement of a pixel from its correct location was measured to be 3.3 mm. The algorithm was tested on intra-subject MR images and was found to produce good qualitative results. Using the data available, the algorithm produced promising qualitative results in intra-subject registration. Further work is necessary in its application to intersubject registration, due to large variability in brain structure between subjects. Clinical evaluation of the algorithm for selected applications is required

  7. Blind image deconvolution methods and convergence

    CERN Document Server

    Chaudhuri, Subhasis; Rameshan, Renu

    2014-01-01

    Blind deconvolution is a classical image processing problem which has been investigated by a large number of researchers over the last four decades. The purpose of this monograph is not to propose yet another method for blind image restoration. Rather the basic issue of deconvolvability has been explored from a theoretical view point. Some authors claim very good results while quite a few claim that blind restoration does not work. The authors clearly detail when such methods are expected to work and when they will not. In order to avoid the assumptions needed for convergence analysis in the

  8. Radiographic imaging method by gas ionisation

    International Nuclear Information System (INIS)

    Eickel, R.; Rheude, A.

    1982-02-01

    The search for a substitute of the silver halide film has been intensified worldwide due to the shortage and price increase of silver metal. Gasionography could be an alternative to the wellknown silver film imaging techniques in roentgenology. Therefore the practical basis of the imaging process and the electrophoretic development was investigated. The technical realisation of this method was demonstrated for two different types of X-ray examen by developing a fully automatic chest changer and a mammography system that can be adapted to commercially available imaging stands. The image quality achieved with these apparatus was evaluated in comparison with conventional film techniques in the laboratory as well as in a clinical trial. (orig.) [de

  9. A multicore based parallel image registration method.

    Science.gov (United States)

    Yang, Lin; Gong, Leiguang; Zhang, Hong; Nosher, John L; Foran, David J

    2009-01-01

    Image registration is a crucial step for many image-assisted clinical applications such as surgery planning and treatment evaluation. In this paper we proposed a landmark based nonlinear image registration algorithm for matching 2D image pairs. The algorithm was shown to be effective and robust under conditions of large deformations. In landmark based registration, the most important step is establishing the correspondence among the selected landmark points. This usually requires an extensive search which is often computationally expensive. We introduced a nonregular data partition algorithm using the K-means clustering algorithm to group the landmarks based on the number of available processing cores. The step optimizes the memory usage and data transfer. We have tested our method using IBM Cell Broadband Engine (Cell/B.E.) platform.

  10. Image-reconstruction methods in positron tomography

    CERN Document Server

    Townsend, David W; CERN. Geneva

    1993-01-01

    Physics and mathematics for medical imaging In the two decades since the introduction of the X-ray scanner into radiology, medical imaging techniques have become widely established as essential tools in the diagnosis of disease. As a consequence of recent technological and mathematical advances, the non-invasive, three-dimensional imaging of internal organs such as the brain and the heart is now possible, not only for anatomical investigations using X-rays but also for studies which explore the functional status of the body using positron-emitting radioisotopes and nuclear magnetic resonance. Mathematical methods which enable three-dimentional distributions to be reconstructed from projection data acquired by radiation detectors suitably positioned around the patient will be described in detail. The lectures will trace the development of medical imaging from simpleradiographs to the present-day non-invasive measurement of in vivo boichemistry. Powerful techniques to correlate anatomy and function that are cur...

  11. 3D Seismic Imaging using Marchenko Methods

    Science.gov (United States)

    Lomas, A.; Curtis, A.

    2017-12-01

    Marchenko methods are novel, data driven techniques that allow seismic wavefields from sources and receivers on the Earth's surface to be redatumed to construct wavefields with sources in the subsurface - including complex multiply-reflected waves, and without the need for a complex reference model. In turn, this allows subsurface images to be constructed at any such subsurface redatuming points (image or virtual receiver points). Such images are then free of artefacts from multiply-scattered waves that usually contaminate migrated seismic images. Marchenko algorithms require as input the same information as standard migration methods: the full reflection response from sources and receivers at the Earth's surface, and an estimate of the first arriving wave between the chosen image point and the surface. The latter can be calculated using a smooth velocity model estimated using standard methods. The algorithm iteratively calculates a signal that focuses at the image point to create a virtual source at that point, and this can be used to retrieve the signal between the virtual source and the surface. A feature of these methods is that the retrieved signals are naturally decomposed into up- and down-going components. That is, we obtain both the signal that initially propagated upwards from the virtual source and arrived at the surface, separated from the signal that initially propagated downwards. Figure (a) shows a 3D subsurface model with a variable density but a constant velocity (3000m/s). Along the surface of this model (z=0) in both the x and y directions are co-located sources and receivers at 20-meter intervals. The redatumed signal in figure (b) has been calculated using Marchenko methods from a virtual source (1200m, 500m and 400m) to the surface. For comparison the true solution is given in figure (c), and shows a good match when compared to figure (b). While these 2D redatuming and imaging methods are still in their infancy having first been developed in

  12. {sup 90}Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Łada, Wiesława, E-mail: w.lada@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Iller, Edward [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Wawszczak, Danuta [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Konior, Marcin, E-mail: marcin.konior@polatom.pl [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Dziel, Tomasz [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland)

    2016-10-01

    A new technology for the production of radiopharmaceutical {sup 90}Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25–100 μm, is stable and free from contaminants. Irradiation of 20 mg samples of grains with diameter of 20–50 μm in the thermal neutron flux of 1.7 × 10{sup 14} cm{sup −2} s{sup −1} at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the {sup 90}Y isotope on the way of the nuclear reaction {sup 89}Y(n, γ){sup 90}Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190 MBq/mg Y. {sup 90}Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies. - Highlights: • Sol-gel methods for preparation of spherical yttrium trioxide grains have been proposed. • Determination condition for irradiation {sup 89}Y{sub 2}O{sub 3} grains in nuclear reactor • Evaluation of specific activity of {sup 90}Y microspheres • Estimation of {sup 90}Y microspheres as promising medical material for radioembolization.

  13. In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Gu MJ

    2015-08-01

    Full Text Available Meng-Jie Gu,1,* Kun-Feng Li,1,* Lan-Xin Zhang,1 Huan Wang,1 Li-Si Liu,2 Zhuo-Zhao Zheng,2 Nan-Yin Han,1 Zhen-Jun Yang,1 Tian-Yuan Fan1 1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 2Department of Radiology, Peking University Third Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs. Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA, gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. Keywords: magnetic resonance imaging, gadolinium, liposomes, tenascin-C, GBI-10 aptamer, tumor targeting

  14. Prognostic Value of Coronary Artery Calcium in the PROMISE Study (Prospective Multicenter Imaging Study for Evaluation of Chest Pain).

    Science.gov (United States)

    Budoff, Matthew J; Mayrhofer, Thomas; Ferencik, Maros; Bittner, Daniel; Lee, Kerry L; Lu, Michael T; Coles, Adrian; Jang, James; Krishnam, Mayil; Douglas, Pamela S; Hoffmann, Udo

    2017-11-21

    Coronary artery calcium (CAC) is an established predictor of future major adverse atherosclerotic cardiovascular events in asymptomatic individuals. However, limited data exist as to how CAC compares with functional testing (FT) in estimating prognosis in symptomatic patients. In the PROMISE trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain), patients with stable chest pain (or dyspnea) and intermediate pretest probability for obstructive coronary artery disease were randomized to FT (exercise electrocardiography, nuclear stress, or stress echocardiography) or anatomic testing. We evaluated those who underwent CAC testing as part of the anatomic evaluation (n=4209) and compared that with results of FT (n=4602). We stratified CAC and FT results as normal or mildly, moderately, or severely abnormal (for CAC: 0, 1-99 Agatston score [AS], 100-400 AS, and >400 AS, respectively; for FT: normal, mild=late positive treadmill, moderate=early positive treadmill or single-vessel ischemia, and severe=large ischemic region abnormality). The primary end point was all-cause death, myocardial infarction, or unstable angina hospitalization over a median follow-up of 26.1 months. Cox regression models were used to calculate hazard ratios (HRs) and C statistics to determine predictive and discriminatory values. Overall, the distribution of normal or mildly, moderately, or severely abnormal test results was significantly different between FT and CAC (FT: normal, n=3588 [78.0%]; mild, n=432 [9.4%]; moderate, n=217 [4.7%]; severe, n=365 [7.9%]; CAC: normal, n=1457 [34.6%]; mild, n=1340 [31.8%]; moderate, n=772 [18.3%]; severe, n=640 [15.2%]; P 0), whereas fewer than half of events occurred in patients with mildly, moderately, or severely abnormal FT (n=57 of 132, 43%; P fair for both CAC and FT (C statistic, 0.67 versus 0.64). Coronary computed tomographic angiography provided significantly better prognostic information compared with FT and CAC testing (C index

  15. Radiopharmaceutical chelates and method of external imaging

    International Nuclear Information System (INIS)

    Loberg, M.D.; Callery, P.S.; Cooper, M.

    1977-01-01

    A chelate of technetium-99m, cobalt-57, gallium-67, gallium-68, indium-111 or indium-113m and a substituted iminodiacetic acid or an 8-hydroxyquinoline useful as a radiopharmaceutical external imaging agent. The invention also includes preparative methods therefor

  16. Standoff Methods for the Detection of Threat Agents: A Review of Several Promising Laser-Based Techniques

    Directory of Open Access Journals (Sweden)

    J. Bruce Johnson

    2014-01-01

    Full Text Available Detection of explosives, explosive precursors, or other threat agents presents a number of technological challenges for optical sensing methods. Certainly detecting trace levels of threat agents against a complex background is chief among these challenges; however, the related issues of multiple target distances (from standoff to proximity and sampling time scales (from passive mines to rapid rate of march convoy protection for different applications make it unlikely that a single technique will be ideal for all sensing situations. A number of methods for spanning the range of optical sensor technologies exist which, when integrated, could produce a fused sensor system possessing a high level of sensitivity to threat agents and a moderate standoff real-time capability appropriate for portal screening of personnel or vehicles. In this work, we focus on several promising, and potentially synergistic, laser-based methods for sensing threat agents. For each method, we have briefly outlined the technique and report on the current level of capability.

  17. Simultaneous Multislice Echo Planar Imaging With Blipped Controlled Aliasing in Parallel Imaging Results in Higher Acceleration: A Promising Technique for Accelerated Diffusion Tensor Imaging of Skeletal Muscle.

    Science.gov (United States)

    Filli, Lukas; Piccirelli, Marco; Kenkel, David; Guggenberger, Roman; Andreisek, Gustav; Beck, Thomas; Runge, Val M; Boss, Andreas

    2015-07-01

    The aim of this study was to investigate the feasibility of accelerated diffusion tensor imaging (DTI) of skeletal muscle using echo planar imaging (EPI) applying simultaneous multislice excitation with a blipped controlled aliasing in parallel imaging results in higher acceleration unaliasing technique. After federal ethics board approval, the lower leg muscles of 8 healthy volunteers (mean [SD] age, 29.4 [2.9] years) were examined in a clinical 3-T magnetic resonance scanner using a 15-channel knee coil. The EPI was performed at a b value of 500 s/mm2 without slice acceleration (conventional DTI) as well as with 2-fold and 3-fold acceleration. Fractional anisotropy (FA) and mean diffusivity (MD) were measured in all 3 acquisitions. Fiber tracking performance was compared between the acquisitions regarding the number of tracks, average track length, and anatomical precision using multivariate analysis of variance and Mann-Whitney U tests. Acquisition time was 7:24 minutes for conventional DTI, 3:53 minutes for 2-fold acceleration, and 2:38 minutes for 3-fold acceleration. Overall FA and MD values ranged from 0.220 to 0.378 and 1.595 to 1.829 mm2/s, respectively. Two-fold acceleration yielded similar FA and MD values (P ≥ 0.901) and similar fiber tracking performance compared with conventional DTI. Three-fold acceleration resulted in comparable MD (P = 0.199) but higher FA values (P = 0.006) and significantly impaired fiber tracking in the soleus and tibialis anterior muscles (number of tracks, P DTI of skeletal muscle with similar image quality and quantification accuracy of diffusion parameters. This may increase the clinical applicability of muscle anisotropy measurements.

  18. Image correlation method for DNA sequence alignment.

    Science.gov (United States)

    Curilem Saldías, Millaray; Villarroel Sassarini, Felipe; Muñoz Poblete, Carlos; Vargas Vásquez, Asticio; Maureira Butler, Iván

    2012-01-01

    The complexity of searches and the volume of genomic data make sequence alignment one of bioinformatics most active research areas. New alignment approaches have incorporated digital signal processing techniques. Among these, correlation methods are highly sensitive. This paper proposes a novel sequence alignment method based on 2-dimensional images, where each nucleic acid base is represented as a fixed gray intensity pixel. Query and known database sequences are coded to their pixel representation and sequence alignment is handled as object recognition in a scene problem. Query and database become object and scene, respectively. An image correlation process is carried out in order to search for the best match between them. Given that this procedure can be implemented in an optical correlator, the correlation could eventually be accomplished at light speed. This paper shows an initial research stage where results were "digitally" obtained by simulating an optical correlation of DNA sequences represented as images. A total of 303 queries (variable lengths from 50 to 4500 base pairs) and 100 scenes represented by 100 x 100 images each (in total, one million base pair database) were considered for the image correlation analysis. The results showed that correlations reached very high sensitivity (99.01%), specificity (98.99%) and outperformed BLAST when mutation numbers increased. However, digital correlation processes were hundred times slower than BLAST. We are currently starting an initiative to evaluate the correlation speed process of a real experimental optical correlator. By doing this, we expect to fully exploit optical correlation light properties. As the optical correlator works jointly with the computer, digital algorithms should also be optimized. The results presented in this paper are encouraging and support the study of image correlation methods on sequence alignment.

  19. New magnetic resonance imaging methods in nephrology

    Science.gov (United States)

    Zhang, Jeff L.; Morrell, Glen; Rusinek, Henry; Sigmund, Eric; Chandarana, Hersh; Lerman, Lilach O.; Prasad, Pottumarthi Vara; Niles, David; Artz, Nathan; Fain, Sean; Vivier, Pierre H.; Cheung, Alfred K.; Lee, Vivian S.

    2013-01-01

    Established as a method to study anatomic changes, such as renal tumors or atherosclerotic vascular disease, magnetic resonance imaging (MRI) to interrogate renal function has only recently begun to come of age. In this review, we briefly introduce some of the most important MRI techniques for renal functional imaging, and then review current findings on their use for diagnosis and monitoring of major kidney diseases. Specific applications include renovascular disease, diabetic nephropathy, renal transplants, renal masses, acute kidney injury and pediatric anomalies. With this review, we hope to encourage more collaboration between nephrologists and radiologists to accelerate the development and application of modern MRI tools in nephrology clinics. PMID:24067433

  20. Three-dimensional image signals: processing methods

    Science.gov (United States)

    Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

    2010-11-01

    Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

  1. Robust boundary detection of left ventricles on ultrasound images using ASM-level set method.

    Science.gov (United States)

    Zhang, Yaonan; Gao, Yuan; Li, Hong; Teng, Yueyang; Kang, Yan

    2015-01-01

    Level set method has been widely used in medical image analysis, but it has difficulties when being used in the segmentation of left ventricular (LV) boundaries on echocardiography images because the boundaries are not very distinguish, and the signal-to-noise ratio of echocardiography images is not very high. In this paper, we introduce the Active Shape Model (ASM) into the traditional level set method to enforce shape constraints. It improves the accuracy of boundary detection and makes the evolution more efficient. The experiments conducted on the real cardiac ultrasound image sequences show a positive and promising result.

  2. Image reconstruction methods in positron tomography

    International Nuclear Information System (INIS)

    Townsend, D.W.; Defrise, M.

    1993-01-01

    In the two decades since the introduction of the X-ray scanner into radiology, medical imaging techniques have become widely established as essential tools in the diagnosis of disease. As a consequence of recent technological and mathematical advances, the non-invasive, three-dimensional imaging of internal organs such as the brain and the heart is now possible, not only for anatomical investigations using X-ray but also for studies which explore the functional status of the body using positron-emitting radioisotopes. This report reviews the historical and physical basis of medical imaging techniques using positron-emitting radioisotopes. Mathematical methods which enable three-dimensional distributions of radioisotopes to be reconstructed from projection data (sinograms) acquired by detectors suitably positioned around the patient are discussed. The extension of conventional two-dimensional tomographic reconstruction algorithms to fully three-dimensional reconstruction is described in detail. (orig.)

  3. Method and apparatus for enhancing radiometric imaging

    International Nuclear Information System (INIS)

    Logan, R. H.; Paradish, F. J.

    1985-01-01

    Disclosed is a method and apparatus for enhancing target detection, particularly in the millimeter wave frequency range, through the utilization of an imaging radiometer. The radiometer, which is a passive thermal receiver, detects the reflected and emitted thermal radiation of targets within a predetermined antenna/receiver beamwidth. By scanning the radiometer over a target area, a thermal image is created. At millimeter wave frequencies, the received emissions from the target area are highly dependent on the emissivity of the target of interest. Foliage will appear ''hot'' due to its high emissivity and metals will appear cold due to their low emissivities. A noise power illuminator is periodically actuated to illuminate the target of interest. When the illuminator is actuated, the role of emissivity is reversed, namely poorly emissive targets will generally be good reflectors which in the presence of an illuminator will appear ''hot''. The highly emissive targets (such as foliage and dirt) which absorb most of the transmitted energy will appear almost the same as in a nonilluminated, passive image. Using a data processor, the intensity of the passive image is subtracted from the intensity of the illuminated, active image which thereby cancels the background foliage, dirt, etc. and the reflective metallic targets are enhanced

  4. Active learning methods for interactive image retrieval.

    Science.gov (United States)

    Gosselin, Philippe Henri; Cord, Matthieu

    2008-07-01

    Active learning methods have been considered with increased interest in the statistical learning community. Initially developed within a classification framework, a lot of extensions are now being proposed to handle multimedia applications. This paper provides algorithms within a statistical framework to extend active learning for online content-based image retrieval (CBIR). The classification framework is presented with experiments to compare several powerful classification techniques in this information retrieval context. Focusing on interactive methods, active learning strategy is then described. The limitations of this approach for CBIR are emphasized before presenting our new active selection process RETIN. First, as any active method is sensitive to the boundary estimation between classes, the RETIN strategy carries out a boundary correction to make the retrieval process more robust. Second, the criterion of generalization error to optimize the active learning selection is modified to better represent the CBIR objective of database ranking. Third, a batch processing of images is proposed. Our strategy leads to a fast and efficient active learning scheme to retrieve sets of online images (query concept). Experiments on large databases show that the RETIN method performs well in comparison to several other active strategies.

  5. Enhancing the (MSLDIP) image steganographic method (ESLDIP method)

    Science.gov (United States)

    Seddik Saad, Al-hussien

    2011-10-01

    Message transmissions over the Internet still have data security problem. Therefore, secure and secret communication methods are needed for transmitting messages over the Internet. Cryptography scrambles the message so that it cannot be understood. However, it makes the message suspicious enough to attract eavesdropper's attention. Steganography hides the secret message within other innocuous-looking cover files (i.e. images, music and video files) so that it cannot be observed [1].The term steganography originates from the Greek root words "steganos'' and "graphein'' which literally mean "covered writing''. It is defined as the science that involves communicating secret data in an appropriate multimedia carrier, e.g., image, audio text and video files [3].Steganographic techniques allow one party to communicate information to another without a third party even knowing that the communication is occurring. The ways to deliver these "secret messages" vary greatly [3].Our proposed method called Enhanced SLDIP (ESLDIP). In which the maximmum hiding capacity (MHC) of proposed ESLDIP method is higher than the previously proposed MSLDIP methods and the PSNR of the ESLDIP method is higher than the MSLDIP PSNR values', which means that the image quality of the ESLDIP method will be better than MSLDIP method and the maximmum hiding capacity (MHC) also improved. The rest of this paper is organized as follows. In section 2, steganography has been discussed; lingo, carriers and types. In section 3, related works are introduced. In section 4, the proposed method will be discussed in details. In section 5, the simulation results are given and Section 6 concludes the paper.

  6. A Frequency Splitting Method For CFM Imaging

    DEFF Research Database (Denmark)

    Udesen, Jesper; Gran, Fredrik; Jensen, Jørgen Arendt

    2006-01-01

    The performance of conventional CFM imaging will often be degraded due to the relatively low number of pulses (4-10) used for each velocity estimate. To circumvent this problem we propose a new method using frequency splitting (FS). The FS method uses broad band chirps as excitation pulses instead...... of narrow band pulses as in conventional CFM imaging. By appropriate filtration, the returned signals are divided into a number of narrow band signals which are approximately disjoint. After clutter filtering the velocities are found from each frequency band using a conventional autocorrelation estimator......, a 5 MHz linear array transducer was used to scan a vessel situated at 30 mm depth with a maximum flow velocity of 0.1 m/s. The pulse repetition frequency was 1.8 kHz and the angle between the flow and the beam was 60 deg. A 15 mus chirp was used as excitation pulse and 40 independent velocity...

  7. Development of an automated extraction method for liver tumors in three dimensional multiphase multislice CT images

    International Nuclear Information System (INIS)

    Nakagawa, Junya; Shimizu, Akinobu; Kobatake, Hidefumi

    2004-01-01

    This paper proposes a tumor detection method using four phase three dimensional (3D) CT images of livers, i.e. non-contrast, early, portal, and late phase images. The method extracts liver regions from the four phase images and enhances tumors in the livers using a 3D adaptive convergence index filter. Then it detects local maximum points and extracts tumor candidates by a region growing method. Subsequently several features of the candidates are measured and each candidate is classified into true tumor or normal tissue based on Mahalanobis distances. Above processes except liver region extraction are applied to four phase images, independently and four resultant images are integrated into one. We applied the proposed method to 3D abdominal CT images of ten patients obtained with multi-detector row CT scanner and confirmed that tumor detection rate was 100% without false positives, which was quite promising results. (author)

  8. A Method for Denoising Image Contours

    Directory of Open Access Journals (Sweden)

    Ovidiu COSMA

    2017-12-01

    Full Text Available The edge detection techniques have to compromise between sensitivity and noise. In order for the main contours to be uninterrupted, the level of sensitivity has to be raised, which however has the negative effect of producing a multitude of insignificant contours (noise. This article proposes a method of removing this noise, which acts directly on the binary representation of the image contours.

  9. Young community of EACVI: the transition from EACVI Club 35 to Heart Imagers of Tomorrow: a promising yet challenging step.

    Science.gov (United States)

    Grapsa, Julia; Cameli, Matteo; Granier, Camille; Muraru, Denisa; Ernande, Laura; Popescu, Bogdan A; Lancellotti, Patrizio; Habib, Gilbert

    2016-02-01

    The purpose of this review is to summarize the activity and potential of the young community of European Association of Cardiovascular Imaging and to highlight the transition from Club 35 to 'Heart Imagers of tomorrow'. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  10. Lung function imaging methods in Cystic Fibrosis pulmonary disease.

    Science.gov (United States)

    Kołodziej, Magdalena; de Veer, Michael J; Cholewa, Marian; Egan, Gary F; Thompson, Bruce R

    2017-05-17

    Monitoring of pulmonary physiology is fundamental to the clinical management of patients with Cystic Fibrosis. The current standard clinical practise uses spirometry to assess lung function which delivers a clinically relevant functional readout of total lung function, however does not supply any visible or localised information. High Resolution Computed Tomography (HRCT) is a well-established current 'gold standard' method for monitoring lung anatomical changes in Cystic Fibrosis patients. HRCT provides excellent morphological information, however, the X-ray radiation dose can become significant if multiple scans are required to monitor chronic diseases such as cystic fibrosis. X-ray phase-contrast imaging is another emerging X-ray based methodology for Cystic Fibrosis lung assessment which provides dynamic morphological and functional information, albeit with even higher X-ray doses than HRCT. Magnetic Resonance Imaging (MRI) is a non-ionising radiation imaging method that is garnering growing interest among researchers and clinicians working with Cystic Fibrosis patients. Recent advances in MRI have opened up the possibilities to observe lung function in real time to potentially allow sensitive and accurate assessment of disease progression. The use of hyperpolarized gas or non-contrast enhanced MRI can be tailored to clinical needs. While MRI offers significant promise it still suffers from poor spatial resolution and the development of an objective scoring system especially for ventilation assessment.

  11. Diffusion weighted imaging by MR method

    International Nuclear Information System (INIS)

    Horikawa, Yoshiharu; Naruse, Shoji; Ebisu, Toshihiko; Tokumitsu, Takuaki; Ueda, Satoshi; Tanaka, Chuzo; Higuchi, Toshihiro; Umeda, Masahiro.

    1993-01-01

    Diffusion weighted magnetic resonance imaging is a recently developed technique used to examine the micromovement of water molecules in vivo. We have applied this technique to examine various kinds of brain diseases, both experimentally and clinically. The calculated apparent diffusion coefficient (ADC) in vivo showed reliable values. In experimentally induced brain edema in rats, the pathophysiological difference of the type of edema (such as cytotoxic, and vasogenic) could be differentiated on the diffusion weighted MR images. Cytotoxic brain edema showed high intensity (slower diffusion) on the diffusion weighted images. On the other hand, vasogenic brain edema showed a low intensity image (faster diffusion). Diffusion anisotropy was demonstrated according to the direction of myelinated fibers and applied motion proving gradient (MPG). This anisotropy was also demonstrated in human brain tissue along the course of the corpus callosum, pyramidal tract and optic radiation. In brain ischemia cases, lesions were detected as high signal intensity areas, even one hour after the onset of ischemia. Diffusion was faster in brain tumor compared with normal brain. Histological differences were not clearly reflected by the ADC value. In epidermoid tumor cases, the intensity was characteristically high, was demonstrated, and the cerebrospinal fluid border was clearly demonstrated. New clinical information obtainable with this molecular diffusion method will prove to be useful in various clinical studies. (author)

  12. A nuclear method to authenticate Buddha images

    International Nuclear Information System (INIS)

    Khaweerat, S; Ratanatongchai, W; Channuie, J; Wonglee, S; Picha, R; Promping, J; Silva, K; Liamsuwan, T

    2015-01-01

    The value of Buddha images in Thailand varies dramatically depending on authentication and provenance. In general, people use their individual skills to make the justification which frequently leads to obscurity, deception and illegal activities. Here, we propose two non-destructive techniques of neutron radiography (NR) and neutron activation autoradiography (NAAR) to reveal respectively structural and elemental profiles of small Buddha images. For NR, a thermal neutron flux of 10 5 n cm -2 s -1 was applied. NAAR needed a higher neutron flux of 10 12 n cm -2 s -1 to activate the samples. Results from NR and NAAR revealed unique characteristic of the samples. Similarity of the profile played a key role in the classification of the samples. The results provided visual evidence to enhance the reliability of authenticity approval. The method can be further developed for routine practice which impact thousands of customers in Thailand. (paper)

  13. A nuclear method to authenticate Buddha images

    Science.gov (United States)

    Khaweerat, S.; Ratanatongchai, W.; Channuie, J.; Wonglee, S.; Picha, R.; Promping, J.; Silva, K.; Liamsuwan, T.

    2015-05-01

    The value of Buddha images in Thailand varies dramatically depending on authentication and provenance. In general, people use their individual skills to make the justification which frequently leads to obscurity, deception and illegal activities. Here, we propose two non-destructive techniques of neutron radiography (NR) and neutron activation autoradiography (NAAR) to reveal respectively structural and elemental profiles of small Buddha images. For NR, a thermal neutron flux of 105 n cm-2s-1 was applied. NAAR needed a higher neutron flux of 1012 n cm-2 s-1 to activate the samples. Results from NR and NAAR revealed unique characteristic of the samples. Similarity of the profile played a key role in the classification of the samples. The results provided visual evidence to enhance the reliability of authenticity approval. The method can be further developed for routine practice which impact thousands of customers in Thailand.

  14. A high-speed computerized tomography image reconstruction using direct two-dimensional Fourier transform method

    International Nuclear Information System (INIS)

    Niki, Noboru; Mizutani, Toshio; Takahashi, Yoshizo; Inouye, Tamon.

    1983-01-01

    The nescessity for developing real-time computerized tomography (CT) aiming at the dynamic observation of organs such as hearts has lately been advocated. It is necessary for its realization to reconstruct the images which are markedly faster than present CTs. Although various reconstructing methods have been proposed so far, the method practically employed at present is the filtered backprojection (FBP) method only, which can give high quality image reconstruction, but takes much computing time. In the past, the two-dimensional Fourier transform (TFT) method was regarded as unsuitable to practical use because the quality of images obtained was not good, in spite of the promising method for high speed reconstruction because of its less computing time. However, since it was revealed that the image quality by TFT method depended greatly on interpolation accuracy in two-dimensional Fourier space, the authors have developed a high-speed calculation algorithm that can obtain high quality images by pursuing the relationship between the image quality and the interpolation method. In this case, radial data sampling points in Fourier space are increased to β-th power of 2 times, and the linear or spline interpolation is used. Comparison of this method with the present FBP method resulted in the conclusion that the image quality is almost the same in practical image matrix, the computational time by TFT method becomes about 1/10 of FBP method, and the memory capacity also reduces by about 20 %. (Wakatsuki, Y.)

  15. Linearized image reconstruction method for ultrasound modulated electrical impedance tomography based on power density distribution

    International Nuclear Information System (INIS)

    Song, Xizi; Xu, Yanbin; Dong, Feng

    2017-01-01

    Electrical resistance tomography (ERT) is a promising measurement technique with important industrial and clinical applications. However, with limited effective measurements, it suffers from poor spatial resolution due to the ill-posedness of the inverse problem. Recently, there has been an increasing research interest in hybrid imaging techniques, utilizing couplings of physical modalities, because these techniques obtain much more effective measurement information and promise high resolution. Ultrasound modulated electrical impedance tomography (UMEIT) is one of the newly developed hybrid imaging techniques, which combines electric and acoustic modalities. A linearized image reconstruction method based on power density is proposed for UMEIT. The interior data, power density distribution, is adopted to reconstruct the conductivity distribution with the proposed image reconstruction method. At the same time, relating the power density change to the change in conductivity, the Jacobian matrix is employed to make the nonlinear problem into a linear one. The analytic formulation of this Jacobian matrix is derived and its effectiveness is also verified. In addition, different excitation patterns are tested and analyzed, and opposite excitation provides the best performance with the proposed method. Also, multiple power density distributions are combined to implement image reconstruction. Finally, image reconstruction is implemented with the linear back-projection (LBP) algorithm. Compared with ERT, with the proposed image reconstruction method, UMEIT can produce reconstructed images with higher quality and better quantitative evaluation results. (paper)

  16. Research of ART method in CT image reconstruction

    International Nuclear Information System (INIS)

    Li Zhipeng; Cong Peng; Wu Haifeng

    2005-01-01

    This paper studied Algebraic Reconstruction Technique (ART) in CT image reconstruction. Discussed the ray number influence on image quality. And the adopting of smooth method got high quality CT image. (authors)

  17. NIR-Cyanine Dye Linker: a Promising Candidate for Isochronic Fluorescence Imaging in Molecular Cancer Diagnostics and Therapy Monitoring.

    Science.gov (United States)

    Komljenovic, Dorde; Wiessler, Manfred; Waldeck, Waldemar; Ehemann, Volker; Pipkorn, Ruediger; Schrenk, Hans-Hermann; Debus, Jürgen; Braun, Klaus

    2016-01-01

    Personalized anti-cancer medicine is boosted by the recent development of molecular diagnostics and molecularly targeted drugs requiring rapid and efficient ligation routes. Here, we present a novel approach to synthetize a conjugate able to act simultaneously as an imaging and as a chemotherapeutic agent by coupling functional peptides employing solid phase peptide synthesis technologies. Development and the first synthesis of a fluorescent dye with similarity in the polymethine part of the Cy7 molecule whose indolenine-N residues were substituted with a propylene linker are described. Methylating agent temozolomide is functionalized with a tetrazine as a diene component whereas Cy7-cell penetrating peptide conjugate acts as a dienophilic reaction partner for the inverse Diels-Alder click chemistry-mediated ligation route yielding a theranostic conjugate, 3-mercapto-propionic-cyclohexenyl-Cy7-bis-temozolomide-bromide-cell penetrating peptide. Synthesis route described here may facilitate targeted delivery of the therapeutic compound to achieve sufficient local concentrations at the target site or tissue. Its versatility allows a choice of adequate imaging tags applicable in e.g. PET, SPECT, CT, near-infrared imaging, and therapeutic substances including cytotoxic agents. Imaging tags and therapeutics may be simultaneously bound to the conjugate applying click chemistry. Theranostic compound presented here offers a solid basis for a further improvement of cancer management in a precise, patient-specific manner.

  18. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

    OpenAIRE

    Adabi, Saba; Turani, Zahra; Fatemizadeh, Emad; Clayton, Anne; Nasiriavanaki, Mohammadreza

    2017-01-01

    Optical coherence tomography (OCT) delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the conseque...

  19. INTEGRATED FUSION METHOD FOR MULTIPLE TEMPORAL-SPATIAL-SPECTRAL IMAGES

    Directory of Open Access Journals (Sweden)

    H. Shen

    2012-08-01

    Full Text Available Data fusion techniques have been widely researched and applied in remote sensing field. In this paper, an integrated fusion method for remotely sensed images is presented. Differently from the existed methods, the proposed method has the performance to integrate the complementary information in multiple temporal-spatial-spectral images. In order to represent and process the images in one unified framework, two general image observation models are firstly presented, and then the maximum a posteriori (MAP framework is used to set up the fusion model. The gradient descent method is employed to solve the fused image. The efficacy of the proposed method is validated using simulated images.

  20. FUSION SEGMENTATION METHOD BASED ON FUZZY THEORY FOR COLOR IMAGES

    Directory of Open Access Journals (Sweden)

    J. Zhao

    2017-09-01

    Full Text Available The image segmentation method based on two-dimensional histogram segments the image according to the thresholds of the intensity of the target pixel and the average intensity of its neighborhood. This method is essentially a hard-decision method. Due to the uncertainties when labeling the pixels around the threshold, the hard-decision method can easily get the wrong segmentation result. Therefore, a fusion segmentation method based on fuzzy theory is proposed in this paper. We use membership function to model the uncertainties on each color channel of the color image. Then, we segment the color image according to the fuzzy reasoning. The experiment results show that our proposed method can get better segmentation results both on the natural scene images and optical remote sensing images compared with the traditional thresholding method. The fusion method in this paper can provide new ideas for the information extraction of optical remote sensing images and polarization SAR images.

  1. Cardiac chamber volumes by echocardiography using a new mathematical method: A promising technique for zero-G use

    Science.gov (United States)

    Buckey, J. C.; Beattie, J. M.; Gaffney, F. A.; Nixon, J. V.; Blomqvist, C. G.

    1984-01-01

    Accurate, reproducible, and non-invasive means for ventricular volume determination are needed for evaluating cardiovascular function zero-gravity. Current echocardiographic methods, particularly for the right ventricle, suffer from a large standard error. A new mathematical approach, recently described by Watanabe et al., was tested on 1 normal formalin-fixed human hearts suspended in a mineral oil bath. Volumes are estimated from multiple two-dimensional echocardiographic views recorded from a single point at sequential angles. The product of sectional cavity area and center of mass for each view summed over the range of angles (using a trapezoidal rule) gives volume. Multiple (8-14) short axis right ventricle and left ventricle views at 5.0 deg intervals were videotaped. The images were digitized by two independent observers (leading-edge to leading-edge technique) and analyzed using a graphics tablet and microcomputer. Actual volumes were determined by filling the chambers with water. These data were compared to the mean of the two echo measurements.

  2. Method and apparatus for imaging volume data

    International Nuclear Information System (INIS)

    Drebin, R.; Carpenter, L.C.

    1987-01-01

    An imaging system projects a two dimensional representation of three dimensional volumes where surface boundaries and objects internal to the volumes are readily shown, and hidden surfaces and the surface boundaries themselves are accurately rendered by determining volume elements or voxels. An image volume representing a volume object or data structure is written into memory. A color and opacity is assigned to each voxel within the volume and stored as a red (R), green (G), blue (B), and opacity (A) component, three dimensional data volume. The RGBA assignment for each voxel is determined based on the percentage component composition of the materials represented in the volume, and thus, the percentage of color and transparency associated with those materials. The voxels in the RGBA volume are used as mathematical filters such that each successive voxel filter is overlayed over a prior background voxel filter. Through a linear interpolation, a new background filter is determined and generated. The interpolation is successively performed for all voxels up to the front most voxel for the plane of view. The method is repeated until all display voxels are determined for the plane of view. (author)

  3. Label-Free Imaging of Female Genital Tract Melanocytic Lesions With Pump-Probe Microscopy: A Promising Diagnostic Tool.

    Science.gov (United States)

    Robles, Francisco E; Deb, Sanghamitra; Fischer, Martin C; Warren, Warren S; Selim, Maria Angelica

    2017-04-01

    Melanomas of the female genital tract present a unique clinical challenge. Not only are these lesions in an anatomically sensitive area, but also they tend to be multifocal and have high recurrence rates. Furthermore, several benign melanocytic proliferations resemble early-stage melanoma clinically and/or histopathologically. Thus, there is a significant need for additional tools that can help correctly diagnose and stage these lesions. Here, we quantitatively and nondestructively analyze the chemical composition of melanin in excised pigmented lesions of the female genital tract using pump-probe microscopy, a high-resolution optical imaging technique that is sensitive to many biochemical properties of melanin. Thirty-one thin (~5 μm) tissue sections previously excised from female genital tract melanocytic lesions were imaged with pump-probe microscopy and analyzed. We find significant quantitative differences in melanin type and structure between melanoma and nonmalignant melanocytic proliferations. Our analysis also suggests a link between the molecular signatures of melanins and lesion-specific genetic mutations. Finally, significant differences are found between metastatic and nonmetastatic melanomas. The limitations of this work include the fact that molecular information is restricted to melanin pigment and the sample size is relatively small. Pump-probe microscopy provides unique information regarding the biochemical composition of genital tract melanocytic lesions, which can be used to improve the diagnosis and staging of vulvar melanomas.

  4. Subsurface imaging by electrical and EM methods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This report consists of 3 subjects. 1) Three dimensional inversion of resistivity data with topography : In this study, we developed a 3-D inversion method based on the finite element calculation of model responses, which can effectively accommodate the irregular topography. In solving the inverse problem, the iterative least-squares approach comprising the smoothness-constraints was taken along with the reciprocity approach in the calculation of Jacobian. Furthermore the Active Constraint Balancing, which has been recently developed by ourselves to enhance the resolving power of the inverse problem, was also employed. Since our new algorithm accounts for the topography in the inversion step, topography correction is not necessary as a preliminary processing and we can expect a more accurate image of the earth. 2) Electromagnetic responses due to a source in the borehole : The effects of borehole fluid and casing on the borehole EM responses should thoroughly be analyzed since they may affect the resultant image of the earth. In this study, we developed an accurate algorithm for calculating the EM responses containing the effects of borehole fluid and casing when a current-carrying ring is located on the borehole axis. An analytic expression for primary vertical magnetic field along the borehole axis was first formulated and the fast Fourier transform is to be applied to get the EM fields at any location in whole space. 3) High frequency electromagnetic impedance survey : At high frequencies the EM impedance becomes a function of the angle of incidence or the horizontal wavenumber, so the electrical properties cannot be readily extracted without first eliminating the effect of horizontal wavenumber on the impedance. For this purpose, this paper considers two independent methods for accurately determining the horizontal wavenumber, which in turn is used to correct the impedance data. The 'apparent' electrical properties derived from the corrected impedance

  5. Image Registration Methode in Radar Interferometry

    Directory of Open Access Journals (Sweden)

    S. Chelbi

    2015-08-01

    Full Text Available This article presents a methodology for the determination of the registration of an Interferometric Synthetic radar (InSAR pair images with half pixel precision. Using the two superposed radar images Single Look complexes (SLC [1-4], we developed an iterative process to superpose these two images according to their correlation coefficient with a high coherence area. This work concerns the exploitation of ERS Tandem pair of radar images SLC of the Algiers area acquired on 03 January and 04 January 1994. The former is taken as a master image and the latter as a slave image.

  6. Numerical methods in image processing for applications in jewellery industry

    OpenAIRE

    Petrla, Martin

    2016-01-01

    Presented thesis deals with a problem from the field of image processing for application in multiple scanning of jewelery stones. The aim is to develop a method for preprocessing and subsequent mathematical registration of images in order to increase the effectivity and reliability of the output quality control. For these purposes the thesis summerizes mathematical definition of digital image as well as theoretical base of image registration. It proposes a method adjusting every single image ...

  7. Keyhole imaging method for dynamic objects behind the occlusion area

    Science.gov (United States)

    Hao, Conghui; Chen, Xi; Dong, Liquan; Zhao, Yuejin; Liu, Ming; Kong, Lingqin; Hui, Mei; Liu, Xiaohua; Wu, Hong

    2018-01-01

    A method of keyhole imaging based on camera array is realized to obtain the video image behind a keyhole in shielded space at a relatively long distance. We get the multi-angle video images by using a 2×2 CCD camera array to take the images behind the keyhole in four directions. The multi-angle video images are saved in the form of frame sequences. This paper presents a method of video frame alignment. In order to remove the non-target area outside the aperture, we use the canny operator and morphological method to realize the edge detection of images and fill the images. The image stitching of four images is accomplished on the basis of the image stitching algorithm of two images. In the image stitching algorithm of two images, the SIFT method is adopted to accomplish the initial matching of images, and then the RANSAC algorithm is applied to eliminate the wrong matching points and to obtain a homography matrix. A method of optimizing transformation matrix is proposed in this paper. Finally, the video image with larger field of view behind the keyhole can be synthesized with image frame sequence in which every single frame is stitched. The results show that the screen of the video is clear and natural, the brightness transition is smooth. There is no obvious artificial stitching marks in the video, and it can be applied in different engineering environment .

  8. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhang, Kai [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhu, Peiping; Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China and Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-02-15

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations.

  9. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili; Zhang, Kai; Zhu, Peiping; Wu, Ziyu

    2015-01-01

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations

  10. [Multimodal medical image registration using cubic spline interpolation method].

    Science.gov (United States)

    He, Yuanlie; Tian, Lianfang; Chen, Ping; Wang, Lifei; Ye, Guangchun; Mao, Zongyuan

    2007-12-01

    Based on the characteristic of the PET-CT multimodal image series, a novel image registration and fusion method is proposed, in which the cubic spline interpolation method is applied to realize the interpolation of PET-CT image series, then registration is carried out by using mutual information algorithm and finally the improved principal component analysis method is used for the fusion of PET-CT multimodal images to enhance the visual effect of PET image, thus satisfied registration and fusion results are obtained. The cubic spline interpolation method is used for reconstruction to restore the missed information between image slices, which can compensate for the shortage of previous registration methods, improve the accuracy of the registration, and make the fused multimodal images more similar to the real image. Finally, the cubic spline interpolation method has been successfully applied in developing 3D-CRT (3D Conformal Radiation Therapy) system.

  11. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

    Science.gov (United States)

    Adabi, Saba; Turani, Zahra; Fatemizadeh, Emad; Clayton, Anne; Nasiriavanaki, Mohammadreza

    2017-01-01

    Optical coherence tomography (OCT) delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts. PMID:28638245

  12. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

    Directory of Open Access Journals (Sweden)

    Saba Adabi

    2017-06-01

    Full Text Available Optical coherence tomography (OCT delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts.

  13. Evaluation of processing methods for static radioisotope scan images

    International Nuclear Information System (INIS)

    Oakberg, J.A.

    1976-12-01

    Radioisotope scanning in the field of nuclear medicine provides a method for the mapping of a radioactive drug in the human body to produce maps (images) which prove useful in detecting abnormalities in vital organs. At best, radioisotope scanning methods produce images with poor counting statistics. One solution to improving the body scan images is using dedicated small computers with appropriate software to process the scan data. Eleven methods for processing image data are compared

  14. Enhancement of Electroluminescence (EL) image measurements for failure quantification methods

    DEFF Research Database (Denmark)

    Parikh, Harsh; Spataru, Sergiu; Sera, Dezso

    2018-01-01

    Enhanced quality images are necessary for EL image analysis and failure quantification. A method is proposed which determines image quality in terms of more accurate failure detection of solar panels through electroluminescence (EL) imaging technique. The goal of the paper is to determine the most...

  15. Method for Surface Scanning in Medical Imaging and Related Apparatus

    DEFF Research Database (Denmark)

    2015-01-01

    A method and apparatus for surface scanning in medical imaging is provided. The surface scanning apparatus comprises an image source, a first optical fiber bundle comprising first optical fibers having proximal ends and distal ends, and a first optical coupler for coupling an image from the image...

  16. Alternate method for to realize image fusion

    International Nuclear Information System (INIS)

    Vargas, L.; Hernandez, F.; Fernandez, R.

    2005-01-01

    At the present time the image departments have the necessity of carrying out image fusion obtained of diverse apparatuses. Conventionally its fuse resonance or tomography images by X-rays with functional images as the gammagrams and PET images. The fusion technology is for sale with the modern image equipment and not all the cabinets of nuclear medicine have access to it. By this reason we analyze, study and we find a solution so that all the cabinets of nuclear medicine can benefit of the image fusion. The first indispensable requirement is to have a personal computer with capacity to put up image digitizer cards. It is also possible, if one has a gamma camera that can export images in JPG, GIF, TIFF or BMP formats, to do without of the digitizer card and to record the images in a disk to be able to use them in the personal computer. It is required of one of the following commercially available graph design programs: Corel Draw, Photo Shop, FreeHand, Illustrator or Macromedia Flash that are those that we evaluate and that its allow to make the images fusion. Anyone of them works well and a short training is required to be able to manage them. It is necessary a photographic digital camera with a resolution of at least 3.0 mega pixel. The procedure consists on taking photographic images of the radiological studies that the patient already has, selecting those demonstrative images of the pathology in study and that its can also be concordant with the images that we have created in the gammagraphic studies, whether for planar or tomographic. We transfer the images to the personal computer and we read them with the graph design program. To continuation also reads the gammagraphic images. We use those digital tools to make transparent the images, to clip them, to adjust the sizes and to create the fused images. The process is manual and it is requires of ability and experience to choose the images, the cuts, those sizes and the transparency grade. (Author)

  17. Promises, pitfalls, and basic guidelines for applying machine learning classifiers to psychiatric imaging data, with autism as an example

    Directory of Open Access Journals (Sweden)

    Pegah Kassraian Fard

    2016-12-01

    Full Text Available Most psychiatric disorders are associated with subtle alterations in brain function and are subject to large inter-individual differences. Typically the diagnosis of these disorders requires time-consuming behavioral assessments administered by a multi-disciplinary team with extensive experience. Whilst the application of machine learning classification methods (ML classifiers to neuroimaging data has the potential to speed and simplify diagnosis of psychiatric disorders, the methods, assumptions, and analytical steps are not currently opaque and accessible to researchers and clinicians outside the field. In this paper, we describe potential classification pipelines for Autism Spectrum Disorder, as an example of a psychiatric disorder. The analyses are based on resting-state fMRI data derived from a multi-site data repository (ABIDE. We compare several popular ML classifiers such as support vector machines, neural networks and regression approaches, among others. In a tutorial style, written to be equally accessible for researchers and clinicians, we explain the rationale of each classification approach, clarify the underlying assumptions, and discuss possible pitfalls and challenges. We also provide the data as well as the MATLAB code we used to achieve our results. We show that out-of-the-box ML classifiers can yield classification accuracies of about 60-70%. Finally, we discuss how classification accuracy can be further improved, and we mention methodological developments that are needed to pave the way for the use of ML classifiers in clinical practice.

  18. 3D Interpolation Method for CT Images of the Lung

    Directory of Open Access Journals (Sweden)

    Noriaki Asada

    2003-06-01

    Full Text Available A 3-D image can be reconstructed from numerous CT images of the lung. The procedure reconstructs a solid from multiple cross section images, which are collected during pulsation of the heart. Thus the motion of the heart is a special factor that must be taken into consideration during reconstruction. The lung exhibits a repeating transformation synchronized to the beating of the heart as an elastic body. There are discontinuities among neighboring CT images due to the beating of the heart, if no special techniques are used in taking CT images. The 3-D heart image is reconstructed from numerous CT images in which both the heart and the lung are taken. Although the outline shape of the reconstructed 3-D heart is quite unnatural, the envelope of the 3-D unnatural heart is fit to the shape of the standard heart. The envelopes of the lung in the CT images are calculated after the section images of the best fitting standard heart are located at the same positions of the CT images. Thus the CT images are geometrically transformed to the optimal CT images fitting best to the standard heart. Since correct transformation of images is required, an Area oriented interpolation method proposed by us is used for interpolation of transformed images. An attempt to reconstruct a 3-D lung image by a series of such operations without discontinuity is shown. Additionally, the same geometrical transformation method to the original projection images is proposed as a more advanced method.

  19. Image Reconstruction Based on Homotopy Perturbation Inversion Method for Electrical Impedance Tomography

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2013-01-01

    Full Text Available The image reconstruction for electrical impedance tomography (EIT mathematically is a typed nonlinear ill-posed inverse problem. In this paper, a novel iteration regularization scheme based on the homotopy perturbation technique, namely, homotopy perturbation inversion method, is applied to investigate the EIT image reconstruction problem. To verify the feasibility and effectiveness, simulations of image reconstruction have been performed in terms of considering different locations, sizes, and numbers of the inclusions, as well as robustness to data noise. Numerical results indicate that this method can overcome the numerical instability and is robust to data noise in the EIT image reconstruction. Moreover, compared with the classical Landweber iteration method, our approach improves the convergence rate. The results are promising.

  20. An efficient direct method for image registration of flat objects

    Science.gov (United States)

    Nikolaev, Dmitry; Tihonkih, Dmitrii; Makovetskii, Artyom; Voronin, Sergei

    2017-09-01

    Image alignment of rigid surfaces is a rapidly developing area of research and has many practical applications. Alignment methods can be roughly divided into two types: feature-based methods and direct methods. Known SURF and SIFT algorithms are examples of the feature-based methods. Direct methods refer to those that exploit the pixel intensities without resorting to image features and image-based deformations are general direct method to align images of deformable objects in 3D space. Nevertheless, it is not good for the registration of images of 3D rigid objects since the underlying structure cannot be directly evaluated. In the article, we propose a model that is suitable for image alignment of rigid flat objects under various illumination models. The brightness consistency assumptions used for reconstruction of optimal geometrical transformation. Computer simulation results are provided to illustrate the performance of the proposed algorithm for computing of an accordance between pixels of two images.

  1. Image Processing Methods Usable for Object Detection on the Chessboard

    Directory of Open Access Journals (Sweden)

    Beran Ladislav

    2016-01-01

    Full Text Available Image segmentation and object detection is challenging problem in many research. Although many algorithms for image segmentation have been invented, there is no simple algorithm for image segmentation and object detection. Our research is based on combination of several methods for object detection. The first method suitable for image segmentation and object detection is colour detection. This method is very simply, but there is problem with different colours. For this method it is necessary to have precisely determined colour of segmented object before all calculations. In many cases it is necessary to determine this colour manually. Alternative simply method is method based on background removal. This method is based on difference between reference image and detected image. In this paper several methods suitable for object detection are described. Thisresearch is focused on coloured object detection on chessboard. The results from this research with fusion of neural networks for user-computer game checkers will be applied.

  2. Finite element formulation for a digital image correlation method

    International Nuclear Information System (INIS)

    Sun Yaofeng; Pang, John H. L.; Wong, Chee Khuen; Su Fei

    2005-01-01

    A finite element formulation for a digital image correlation method is presented that will determine directly the complete, two-dimensional displacement field during the image correlation process on digital images. The entire interested image area is discretized into finite elements that are involved in the common image correlation process by use of our algorithms. This image correlation method with finite element formulation has an advantage over subset-based image correlation methods because it satisfies the requirements of displacement continuity and derivative continuity among elements on images. Numerical studies and a real experiment are used to verify the proposed formulation. Results have shown that the image correlation with the finite element formulation is computationally efficient, accurate, and robust

  3. Perceptual digital imaging methods and applications

    CERN Document Server

    Lukac, Rastislav

    2012-01-01

    Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of tradition

  4. New LSB-based colour image steganography method to enhance ...

    Indian Academy of Sciences (India)

    Mustafa Cem kasapbaşi

    2018-04-27

    Apr 27, 2018 ... evaluate the proposed method, comparative performance tests are carried out against different spatial image ... image steganography applications based on LSB are ..... worst case scenario could occur when having highest.

  5. ISAR imaging using the instantaneous range instantaneous Doppler method

    CSIR Research Space (South Africa)

    Wazna, TM

    2015-10-01

    Full Text Available In Inverse Synthetic Aperture Radar (ISAR) imaging, the Range Instantaneous Doppler (RID) method is used to compensate for the nonuniform rotational motion of the target that degrades the Doppler resolution of the ISAR image. The Instantaneous Range...

  6. Improved radionuclide bone imaging agent injection needle withdrawal method can improve image quality

    International Nuclear Information System (INIS)

    Qin Yongmei; Wang Laihao; Zhao Lihua; Guo Xiaogang; Kong Qingfeng

    2009-01-01

    Objective: To investigate the improvement of radionuclide bone imaging agent injection needle withdrawal method on whole body bone scan image quality. Methods: Elbow vein injection syringe needle directly into the bone imaging agent in the routine group of 117 cases, with a cotton swab needle injection method for the rapid pull out the needle puncture point pressing, pressing moment. Improvement of 117 cases of needle injection method to put two needles into the skin swabs and blood vessels, pull out the needle while pressing two or more entry point 5min. After 2 hours underwent whole body bone SPECT imaging plane. Results: The conventional group at the injection site imaging agents uptake rate was 16.24%, improved group was 2.56%. Conclusion: The modified bone imaging agent injection needle withdrawal method, injection-site imaging agent uptake were significantly decreased whole body bone imaging can improve image quality. (authors)

  7. Comparative analysis of different methods for image enhancement

    Institute of Scientific and Technical Information of China (English)

    吴笑峰; 胡仕刚; 赵瑾; 李志明; 李劲; 唐志军; 席在芳

    2014-01-01

    Image enhancement technology plays a very important role to improve image quality in image processing. By enhancing some information and restraining other information selectively, it can improve image visual effect. The objective of this work is to implement the image enhancement to gray scale images using different techniques. After the fundamental methods of image enhancement processing are demonstrated, image enhancement algorithms based on space and frequency domains are systematically investigated and compared. The advantage and defect of the above-mentioned algorithms are analyzed. The algorithms of wavelet based image enhancement are also deduced and generalized. Wavelet transform modulus maxima (WTMM) is a method for detecting the fractal dimension of a signal, it is well used for image enhancement. The image techniques are compared by using the mean (μ), standard deviation (s), mean square error (MSE) and PSNR (peak signal to noise ratio). A group of experimental results demonstrate that the image enhancement algorithm based on wavelet transform is effective for image de-noising and enhancement. Wavelet transform modulus maxima method is one of the best methods for image enhancement.

  8. System and method for image mapping and visual attention

    Science.gov (United States)

    Peters, II, Richard A. (Inventor)

    2011-01-01

    A method is described for mapping dense sensory data to a Sensory Ego Sphere (SES). Methods are also described for finding and ranking areas of interest in the images that form a complete visual scene on an SES. Further, attentional processing of image data is best done by performing attentional processing on individual full-size images from the image sequence, mapping each attentional location to the nearest node, and then summing all attentional locations at each node.

  9. Apparatus and method X-ray image processing

    International Nuclear Information System (INIS)

    1984-01-01

    The invention relates to a method for X-ray image processing. The radiation passed through the object is transformed into an electric image signal from which the logarithmic value is determined and displayed by a display device. Its main objective is to provide a method and apparatus that renders X-ray images or X-ray subtraction images with strong reduction of stray radiation. (Auth.)

  10. A comparative study on medical image segmentation methods

    Directory of Open Access Journals (Sweden)

    Praylin Selva Blessy SELVARAJ ASSLEY

    2014-03-01

    Full Text Available Image segmentation plays an important role in medical images. It has been a relevant research area in computer vision and image analysis. Many segmentation algorithms have been proposed for medical images. This paper makes a review on segmentation methods for medical images. In this survey, segmentation methods are divided into five categories: region based, boundary based, model based, hybrid based and atlas based. The five different categories with their principle ideas, advantages and disadvantages in segmenting different medical images are discussed.

  11. An Image Encryption Method Based on Bit Plane Hiding Technology

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; LI Zhitang; TU Hao

    2006-01-01

    A novel image hiding method based on the correlation analysis of bit plane is described in this paper. Firstly, based on the correlation analysis, different bit plane of a secret image is hided in different bit plane of several different open images. And then a new hiding image is acquired by a nesting "Exclusive-OR" operation on those images obtained from the first step. At last, by employing image fusion technique, the final hiding result is achieved. The experimental result shows that the method proposed in this paper is effective.

  12. Comparison of whole-body-imaging methods

    International Nuclear Information System (INIS)

    Rollo, F.D.; Hoffer, P.

    1977-01-01

    Currently there are four different devices that have found clinical utility in whole-body imaging. These are the rectilinear scanner, the multicrystal whole-body scanner, the Anger-type camera with a whole-body-imaging table, and the tomoscanner. In this text, the basic theory of operation and a discussion of the advantages and disadvantages in whole-body imaging is presented for each device. When applicable, a comparative assessment of the various devices is also presented. As with all else in life, there is no simple answer to the question ''which total body imaging device is best.'' Institutions with a very heavy total-body-imaging load may prefer to use an already available dual-headed rectilinear scanner system for these studies, rather than invest in a new instrument. Institutions with moderate total-body-imaging loads may wish to invest in moving table or moving camera devices which make total body imaging more convenient but retain the basic flexibility of the camera. The large-field Anger camera with or without motion offers another flexible option to these institutions. The laboratory with a very heavy total body imaging load may select efficiency over flexibility, thereby freeing up other instruments for additional studies. Finally, reliability as well as availability and quality of local service must be considered. After all, design features of an instrument become irrelevant when it is broken down and awaiting repair

  13. The Z-isomer of 11β-methoxy-17α-[123I]iodovinylestradiol is a promising radioligand for estrogen receptor imaging in human breast cancer

    International Nuclear Information System (INIS)

    Rijks, Leonie J. M.; Boer, Gerard J.; Endert, Erik; Bruin, Kora de; Janssen, Anton G. M.; Royen, Eric A. van

    1997-01-01

    The potential of both stereoisomers of 11β-methoxy-17α-[ 123 I]iodovinylestradiol (E- and Z-[ 123 I]MIVE) as suitable radioligands for imaging of estrogen receptor(ER)-positive human breast tumours was studied. The 17α-[ 123 I]iodovinylestradiol derivatives were prepared stereospecifically by oxidative radioiododestannylation of the corresponding 17α-tri-n-butylstannylvinylestradiol precursors. Both isomers of MIVE showed high in vitro affinity for dimethylbenzanthracene-induced rat and fresh human mammary tumour ER, that of Z-MIVE however being manyfold higher than that of E-MIVE. In vivo distribution studies with E- and Z-[ 123 I]MIVE in normal and tumour-bearing female rats showed ER-mediated uptake and retention in uterus, ovaries, pituitary, hypothalamus and mammary tumours, again the highest for Z-[ 123 I]MIVE. The uterus- and tumour-to-nontarget tissue (fat, muscle) uptake ratios were also highest for Z-[ 123 I]MIVE. Additionally, planar whole body imaging of two breast cancer patients 1-2 h after injection of Z-[ 123 I]MIVE showed increased focal uptake at known tumour sites. Therefore, we conclude that Z-[ 123 I]MIVE is a promising radioligand for the diagnostic imaging of ER in human breast cancer

  14. An overview of methods to mitigate artifacts in optical coherence tomography imaging of the skin.

    Science.gov (United States)

    Adabi, Saba; Fotouhi, Audrey; Xu, Qiuyun; Daveluy, Steve; Mehregan, Darius; Podoleanu, Adrian; Nasiriavanaki, Mohammadreza

    2018-05-01

    Optical coherence tomography (OCT) of skin delivers three-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution modality, OCT images suffer from some artifacts that lead to misinterpretation of tissue structures. Therefore, an overview of methods to mitigate artifacts in OCT imaging of the skin is of paramount importance. Speckle, intensity decay, and blurring are three major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. Two speckle reduction methods (one based on artificial neural network and one based on spatial compounding), an attenuation compensation algorithm (based on Beer-Lambert law) and a deblurring procedure (using deconvolution), are described. Moreover, optical properties extraction algorithm based on extended Huygens-Fresnel (EHF) principle to obtain some additional information from OCT images are discussed. In this short overview, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts. The results showed a significant improvement in the visibility of the clinically relevant features in the images. The quality improvement was evaluated using several numerical assessment measures. Clinical dermatologists benefit from using these image enhancement algorithms to improve OCT diagnosis and essentially function as a noninvasive optical biopsy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Methods of fetal MR: beyond T2-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna (Austria)]. E-mail: peter.brugger@meduniwien.ac.at; Stuhr, Fritz [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria); Lindner, Christian [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria); Prayer, Daniela [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria)

    2006-02-15

    The present work reviews the basic methods of performing fetal magnetic resonance imaging (MRI). Since fetal MRI differs in many respects from a postnatal study, several factors have to be taken into account to achieve satisfying image quality. Image quality depends on adequate positioning of the pregnant woman in the magnet, use of appropriate coils and the selection of sequences. Ultrafast T2-weighted sequences are regarded as the mainstay of fetal MR-imaging. However, additional sequences, such as T1-weighted images, diffusion-weighted images, echoplanar imaging may provide further information, especially in extra- central-nervous system regions of the fetal body.

  16. Methods of fetal MR: beyond T2-weighted imaging

    International Nuclear Information System (INIS)

    Brugger, Peter C.; Stuhr, Fritz; Lindner, Christian; Prayer, Daniela

    2006-01-01

    The present work reviews the basic methods of performing fetal magnetic resonance imaging (MRI). Since fetal MRI differs in many respects from a postnatal study, several factors have to be taken into account to achieve satisfying image quality. Image quality depends on adequate positioning of the pregnant woman in the magnet, use of appropriate coils and the selection of sequences. Ultrafast T2-weighted sequences are regarded as the mainstay of fetal MR-imaging. However, additional sequences, such as T1-weighted images, diffusion-weighted images, echoplanar imaging may provide further information, especially in extra- central-nervous system regions of the fetal body

  17. Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

    Directory of Open Access Journals (Sweden)

    Kuang Tsan Lin

    2014-01-01

    Full Text Available The Rivest-Shamir-Adleman (RSA encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matrix holographic image contain seven groups of codes used for reconstructing the covert image. The seven groups of codes are identification codes, covert-image dimension codes, covert-image graylevel codes, pre-RSA bit number codes, RSA key codes, post-RSA bit number codes, and information codes. The reconstructed covert image derived from the dot-matrix holographic image and the original covert image are exactly the same.

  18. Research on image complexity evaluation method based on color information

    Science.gov (United States)

    Wang, Hao; Duan, Jin; Han, Xue-hui; Xiao, Bo

    2017-11-01

    In order to evaluate the complexity of a color image more effectively and find the connection between image complexity and image information, this paper presents a method to compute the complexity of image based on color information.Under the complexity ,the theoretical analysis first divides the complexity from the subjective level, divides into three levels: low complexity, medium complexity and high complexity, and then carries on the image feature extraction, finally establishes the function between the complexity value and the color characteristic model. The experimental results show that this kind of evaluation method can objectively reconstruct the complexity of the image from the image feature research. The experimental results obtained by the method of this paper are in good agreement with the results of human visual perception complexity,Color image complexity has a certain reference value.

  19. A new method for mobile phone image denoising

    Science.gov (United States)

    Jin, Lianghai; Jin, Min; Li, Xiang; Xu, Xiangyang

    2015-12-01

    Images captured by mobile phone cameras via pipeline processing usually contain various kinds of noises, especially granular noise with different shapes and sizes in both luminance and chrominance channels. In chrominance channels, noise is closely related to image brightness. To improve image quality, this paper presents a new method to denoise such mobile phone images. The proposed scheme converts the noisy RGB image to luminance and chrominance images, which are then denoised by a common filtering framework. The common filtering framework processes a noisy pixel by first excluding the neighborhood pixels that significantly deviate from the (vector) median and then utilizing the other neighborhood pixels to restore the current pixel. In the framework, the strength of chrominance image denoising is controlled by image brightness. The experimental results show that the proposed method obviously outperforms some other representative denoising methods in terms of both objective measure and visual evaluation.

  20. New mobile methods for dietary assessment: review of image-assisted and image-based dietary assessment methods.

    Science.gov (United States)

    Boushey, C J; Spoden, M; Zhu, F M; Delp, E J; Kerr, D A

    2017-08-01

    For nutrition practitioners and researchers, assessing dietary intake of children and adults with a high level of accuracy continues to be a challenge. Developments in mobile technologies have created a role for images in the assessment of dietary intake. The objective of this review was to examine peer-reviewed published papers covering development, evaluation and/or validation of image-assisted or image-based dietary assessment methods from December 2013 to January 2016. Images taken with handheld devices or wearable cameras have been used to assist traditional dietary assessment methods for portion size estimations made by dietitians (image-assisted methods). Image-assisted approaches can supplement either dietary records or 24-h dietary recalls. In recent years, image-based approaches integrating application technology for mobile devices have been developed (image-based methods). Image-based approaches aim at capturing all eating occasions by images as the primary record of dietary intake, and therefore follow the methodology of food records. The present paper reviews several image-assisted and image-based methods, their benefits and challenges; followed by details on an image-based mobile food record. Mobile technology offers a wide range of feasible options for dietary assessment, which are easier to incorporate into daily routines. The presented studies illustrate that image-assisted methods can improve the accuracy of conventional dietary assessment methods by adding eating occasion detail via pictures captured by an individual (dynamic images). All of the studies reduced underreporting with the help of images compared with results with traditional assessment methods. Studies with larger sample sizes are needed to better delineate attributes with regards to age of user, degree of error and cost.

  1. Separation method of heavy-ion particle image from gamma-ray mixed images using an imaging plate

    CERN Document Server

    Yamadera, A; Ohuchi, H; Nakamura, T; Fukumura, A

    1999-01-01

    We have developed a separation method of alpha-ray and gamma-ray images using the imaging plate (IP). The IP from which the first image was read out by an image reader was annealed at 50 deg. C for 2 h in a drying oven and the second image was read out by the image reader. It was found out that an annealing ratio, k, which is defined as a ratio of the photo-stimulated luminescence (PSL) density at the first measurement to that at the second measurement, was different for alpha rays and gamma rays. By subtracting the second image multiplied by a factor of k from the first image, the alpha-ray image was separated from the alpha and gamma-ray mixed images. This method was applied to identify the images of helium, carbon and neon particles of high energies using the heavy-ion medical accelerator, HIMAC. (author)

  2. Quantum dynamic imaging theoretical and numerical methods

    CERN Document Server

    Ivanov, Misha

    2011-01-01

    Studying and using light or "photons" to image and then to control and transmit molecular information is among the most challenging and significant research fields to emerge in recent years. One of the fastest growing areas involves research in the temporal imaging of quantum phenomena, ranging from molecular dynamics in the femto (10-15s) time regime for atomic motion to the atto (10-18s) time scale of electron motion. In fact, the attosecond "revolution" is now recognized as one of the most important recent breakthroughs and innovations in the science of the 21st century. A major participant in the development of ultrafast femto and attosecond temporal imaging of molecular quantum phenomena has been theory and numerical simulation of the nonlinear, non-perturbative response of atoms and molecules to ultrashort laser pulses. Therefore, imaging quantum dynamics is a new frontier of science requiring advanced mathematical approaches for analyzing and solving spatial and temporal multidimensional partial differ...

  3. Swept-frequency feedback interferometry using terahertz frequency QCLs: a method for imaging and materials analysis.

    Science.gov (United States)

    Rakić, Aleksandar D; Taimre, Thomas; Bertling, Karl; Lim, Yah Leng; Dean, Paul; Indjin, Dragan; Ikonić, Zoran; Harrison, Paul; Valavanis, Alexander; Khanna, Suraj P; Lachab, Mohammad; Wilson, Stephen J; Linfield, Edmund H; Davies, A Giles

    2013-09-23

    The terahertz (THz) frequency quantum cascade laser (QCL) is a compact source of high-power radiation with a narrow intrinsic linewidth. As such, THz QCLs are extremely promising sources for applications including high-resolution spectroscopy, heterodyne detection, and coherent imaging. We exploit the remarkable phase-stability of THz QCLs to create a coherent swept-frequency delayed self-homodyning method for both imaging and materials analysis, using laser feedback interferometry. Using our scheme we obtain amplitude-like and phase-like images with minimal signal processing. We determine the physical relationship between the operating parameters of the laser under feedback and the complex refractive index of the target and demonstrate that this coherent detection method enables extraction of complex refractive indices with high accuracy. This establishes an ultimately compact and easy-to-implement THz imaging and materials analysis system, in which the local oscillator, mixer, and detector are all combined into a single laser.

  4. Blind compressed sensing image reconstruction based on alternating direction method

    Science.gov (United States)

    Liu, Qinan; Guo, Shuxu

    2018-04-01

    In order to solve the problem of how to reconstruct the original image under the condition of unknown sparse basis, this paper proposes an image reconstruction method based on blind compressed sensing model. In this model, the image signal is regarded as the product of a sparse coefficient matrix and a dictionary matrix. Based on the existing blind compressed sensing theory, the optimal solution is solved by the alternative minimization method. The proposed method solves the problem that the sparse basis in compressed sensing is difficult to represent, which restrains the noise and improves the quality of reconstructed image. This method ensures that the blind compressed sensing theory has a unique solution and can recover the reconstructed original image signal from a complex environment with a stronger self-adaptability. The experimental results show that the image reconstruction algorithm based on blind compressed sensing proposed in this paper can recover high quality image signals under the condition of under-sampling.

  5. Novel welding image processing method based on fractal theory

    Institute of Scientific and Technical Information of China (English)

    陈强; 孙振国; 肖勇; 路井荣

    2002-01-01

    Computer vision has come into used in the fields of welding process control and automation. In order to improve precision and rapidity of welding image processing, a novel method based on fractal theory has been put forward in this paper. Compared with traditional methods, the image is preliminarily processed in the macroscopic regions then thoroughly analyzed in the microscopic regions in the new method. With which, an image is divided up to some regions according to the different fractal characters of image edge, and the fuzzy regions including image edges are detected out, then image edges are identified with Sobel operator and curved by LSM (Lease Square Method). Since the data to be processed have been decreased and the noise of image has been reduced, it has been testified through experiments that edges of weld seam or weld pool could be recognized correctly and quickly.

  6. Blind Methods for Detecting Image Fakery

    Czech Academy of Sciences Publication Activity Database

    Mahdian, Babak; Saic, Stanislav

    2010-01-01

    Roč. 25, č. 4 (2010), s. 18-24 ISSN 0885-8985 R&D Projects: GA ČR GA102/08/0470 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image forensics * Image Fakery * Forgery detection * Authentication Subject RIV: BD - Theory of Information Impact factor: 0.179, year: 2010 http://library.utia.cas.cz/separaty/2010/ZOI/saic-0343316.pdf

  7. Speckle imaging using the principle value decomposition method

    International Nuclear Information System (INIS)

    Sherman, J.W.

    1978-01-01

    Obtaining diffraction-limited images in the presence of atmospheric turbulence is a topic of current interest. Two types of approaches have evolved: real-time correction and speckle imaging. A speckle imaging reconstruction method was developed by use of an ''optimal'' filtering approach. This method is based on a nonlinear integral equation which is solved by principle value decomposition. The method was implemented on a CDC 7600 for study. The restoration algorithm is discussed and its performance is illustrated. 7 figures

  8. Survey: interpolation methods for whole slide image processing.

    Science.gov (United States)

    Roszkowiak, L; Korzynska, A; Zak, J; Pijanowska, D; Swiderska-Chadaj, Z; Markiewicz, T

    2017-02-01

    Evaluating whole slide images of histological and cytological samples is used in pathology for diagnostics, grading and prognosis . It is often necessary to rescale whole slide images of a very large size. Image resizing is one of the most common applications of interpolation. We collect the advantages and drawbacks of nine interpolation methods, and as a result of our analysis, we try to select one interpolation method as the preferred solution. To compare the performance of interpolation methods, test images were scaled and then rescaled to the original size using the same algorithm. The modified image was compared to the original image in various aspects. The time needed for calculations and results of quantification performance on modified images were also compared. For evaluation purposes, we used four general test images and 12 specialized biological immunohistochemically stained tissue sample images. The purpose of this survey is to determine which method of interpolation is the best to resize whole slide images, so they can be further processed using quantification methods. As a result, the interpolation method has to be selected depending on the task involving whole slide images. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  9. On a selection method of imaging condition in scintigraphy

    International Nuclear Information System (INIS)

    Ikeda, Hozumi; Kishimoto, Kenji; Shimonishi, Yoshihiro; Ohmura, Masahiro; Kosakai, Kazuhisa; Ochi, Hironobu

    1992-01-01

    Selection of imaging condition in scintigraphy was evaluated using analytic hierarchy process. First, a method of the selection was led by determining at the points of image quantity and imaging time. Influence of image quality was thought to depend on changes of system resolution, count density, image size, and image density. Also influence of imaging time was thought to depend on changes of system sensitivity and data acquisition time. Phantom study was done for paired comparison of these selection factors, and relations of sample data and the factors, that is Rollo phantom images were taken by changing count density, image size, and image density. Image quality was shown by calculating the score of visual evaluation that done by comparing of a pair of images in clearer cold lesion on the scintigrams. Imaging time was shown by relative values for changes of count density. However, system resolution and system sensitivity were constant in this study. Next, using these values analytic hierarchy process was adapted for this selection of imaging conditions. We conclude that this selection of imaging conditions can be analyzed quantitatively using analytic hierarchy process and this analysis develops theoretical consideration of imaging technique. (author)

  10. Methods of filtering the graph images of the functions

    Directory of Open Access Journals (Sweden)

    Олександр Григорович Бурса

    2017-06-01

    Full Text Available The theoretical aspects of cleaning raster images of scanned graphs of functions from digital, chromatic and luminance distortions by using computer graphics techniques have been considered. The basic types of distortions characteristic of graph images of functions have been stated. To suppress the distortion several methods, providing for high-quality of the resulting images and saving their topological features, were suggested. The paper describes the techniques developed and improved by the authors: the method of cleaning the image of distortions by means of iterative contrasting, based on the step-by-step increase in image contrast in the graph by 1%; the method of small entities distortion restoring, based on the thinning of the known matrix of contrast increase filter (the allowable dimensions of the nucleus dilution radius convolution matrix, which provide for the retention of the graph lines have been established; integration technique of the noise reduction method by means of contrasting and distortion restoring method of small entities with known σ-filter. Each method in the complex has been theoretically substantiated. The developed methods involve treatment of graph images as the entire image (global processing and its fragments (local processing. The metrics assessing the quality of the resulting image with the global and local processing have been chosen, the substantiation of the choice as well as the formulas have been given. The proposed complex methods of cleaning the graphs images of functions from grayscale image distortions is adaptive to the form of an image carrier, the distortion level in the image and its distribution. The presented results of testing the developed complex of methods for a representative sample of images confirm its effectiveness

  11. Wavelet imaging cleaning method for atmospheric Cherenkov telescopes

    Science.gov (United States)

    Lessard, R. W.; Cayón, L.; Sembroski, G. H.; Gaidos, J. A.

    2002-07-01

    We present a new method of image cleaning for imaging atmospheric Cherenkov telescopes. The method is based on the utilization of wavelets to identify noise pixels in images of gamma-ray and hadronic induced air showers. This method selects more signal pixels with Cherenkov photons than traditional image processing techniques. In addition, the method is equally efficient at rejecting pixels with noise alone. The inclusion of more signal pixels in an image of an air shower allows for a more accurate reconstruction, especially at lower gamma-ray energies that produce low levels of light. We present the results of Monte Carlo simulations of gamma-ray and hadronic air showers which show improved angular resolution using this cleaning procedure. Data from the Whipple Observatory's 10-m telescope are utilized to show the efficacy of the method for extracting a gamma-ray signal from the background of hadronic generated images.

  12. Training Methods for Image Noise Level Estimation on Wavelet Components

    Directory of Open Access Journals (Sweden)

    A. De Stefano

    2004-12-01

    Full Text Available The estimation of the standard deviation of noise contaminating an image is a fundamental step in wavelet-based noise reduction techniques. The method widely used is based on the mean absolute deviation (MAD. This model-based method assumes specific characteristics of the noise-contaminated image component. Three novel and alternative methods for estimating the noise standard deviation are proposed in this work and compared with the MAD method. Two of these methods rely on a preliminary training stage in order to extract parameters which are then used in the application stage. The sets used for training and testing, 13 and 5 images, respectively, are fully disjoint. The third method assumes specific statistical distributions for image and noise components. Results showed the prevalence of the training-based methods for the images and the range of noise levels considered.

  13. Distributed MIMO-ISAR Sub-image Fusion Method

    Directory of Open Access Journals (Sweden)

    Gu Wenkun

    2017-02-01

    Full Text Available The fast fluctuation associated with maneuvering a target’s radar cross-section often affects the imaging performance stability of traditional monostatic Inverse Synthetic Aperture Radar (ISAR. To address this problem, in this study, we propose an imaging method based on the fusion of sub-images of frequencydiversity-distributed multiple Input-Multiple Output-Inverse Synthetic Aperture Radar (MIMO-ISAR. First, we establish the analytic expression of a two-dimensional ISAR sub-image acquired by different channels of distributed MIMO-ISAR. Then, we derive the distance and azimuth distortion factors of the image acquired by the different channels. By compensating for the distortion of the ISAR image, we ultimately realize distributed MIMO-ISAR fusion imaging. Simulations verify the validity of this imaging method using distributed MIMO-ISAR.

  14. Investigation of Optimal Integrated Circuit Raster Image Vectorization Method

    Directory of Open Access Journals (Sweden)

    Leonas Jasevičius

    2011-03-01

    Full Text Available Visual analysis of integrated circuit layer requires raster image vectorization stage to extract layer topology data to CAD tools. In this paper vectorization problems of raster IC layer images are presented. Various line extraction from raster images algorithms and their properties are discussed. Optimal raster image vectorization method was developed which allows utilization of common vectorization algorithms to achieve the best possible extracted vector data match with perfect manual vectorization results. To develop the optimal method, vectorized data quality dependence on initial raster image skeleton filter selection was assessed.Article in Lithuanian

  15. A SAR IMAGE REGISTRATION METHOD BASED ON SIFT ALGORITHM

    Directory of Open Access Journals (Sweden)

    W. Lu

    2017-09-01

    Full Text Available In order to improve the stability and rapidity of synthetic aperture radar (SAR images matching, an effective method was presented. Firstly, the adaptive smoothing filtering was employed for image denoising in image processing based on Wallis filtering to avoid the follow-up noise is amplified. Secondly, feature points were extracted by a simplified SIFT algorithm. Finally, the exact matching of the images was achieved with these points. Compared with the existing methods, it not only maintains the richness of features, but a-lso reduces the noise of the image. The simulation results show that the proposed algorithm can achieve better matching effect.

  16. IMAGING WOOD PLASTIC COMPOSITES (WPCs: X-RAY COMPUTED TOMOGRAPHY, A FEW OTHER PROMISING TECHNIQUES, AND WHY WE SHOULD PAY ATTENTION

    Directory of Open Access Journals (Sweden)

    Lech Muszyński

    2009-08-01

    Full Text Available Wood plastic composites are complex, anisotropic, and heterogeneous materials. A key to increasing the share of the WPC materials in the market is developing stronger, highly engineered WPCs characterized by greater structural performance and increased durability. These are achieved by enhanced manufacturing processes, more efficient profile designs, and new formulations providing better interaction between the wood particles and the plastic matrix. Significant progress in this area is hard to imagine without better understanding of the composite performance and internal bond durability on the micro-mechanical level, and reliable modeling based on that understanding. The objective of this paper is to present a brief review of promising material characterization techniques based on advanced imaging technologies and inverse problem methodology, which seem particularly suitable for complex heterogeneous composites. Full-field imaging techniques and specifically X-ray computed tomography (CT combined with numerical modeling tools have a potential to advance the fundamental knowledge on the effect of manufacturing parameters on the micromechanics of such materials and their response to loads and environmental exposure.

  17. A method for fast automated microscope image stitching.

    Science.gov (United States)

    Yang, Fan; Deng, Zhen-Sheng; Fan, Qiu-Hong

    2013-05-01

    Image stitching is an important technology to produce a panorama or larger image by combining several images with overlapped areas. In many biomedical researches, image stitching is highly desirable to acquire a panoramic image which represents large areas of certain structures or whole sections, while retaining microscopic resolution. In this study, we develop a fast normal light microscope image stitching algorithm based on feature extraction. At first, an algorithm of scale-space reconstruction of speeded-up robust features (SURF) was proposed to extract features from the images to be stitched with a short time and higher repeatability. Then, the histogram equalization (HE) method was employed to preprocess the images to enhance their contrast for extracting more features. Thirdly, the rough overlapping zones of the images preprocessed were calculated by phase correlation, and the improved SURF was used to extract the image features in the rough overlapping areas. Fourthly, the features were corresponded by matching algorithm and the transformation parameters were estimated, then the images were blended seamlessly. Finally, this procedure was applied to stitch normal light microscope images to verify its validity. Our experimental results demonstrate that the improved SURF algorithm is very robust to viewpoint, illumination, blur, rotation and zoom of the images and our method is able to stitch microscope images automatically with high precision and high speed. Also, the method proposed in this paper is applicable to registration and stitching of common images as well as stitching the microscope images in the field of virtual microscope for the purpose of observing, exchanging, saving, and establishing a database of microscope images. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. On two methods of statistical image analysis

    NARCIS (Netherlands)

    Missimer, J; Knorr, U; Maguire, RP; Herzog, H; Seitz, RJ; Tellman, L; Leenders, K.L.

    1999-01-01

    The computerized brain atlas (CBA) and statistical parametric mapping (SPM) are two procedures for voxel-based statistical evaluation of PET activation studies. Each includes spatial standardization of image volumes, computation of a statistic, and evaluation of its significance. In addition,

  19. Ultrasound Imaging Methods for Breast Cancer Detection

    NARCIS (Netherlands)

    Ozmen, N.

    2014-01-01

    The main focus of this thesis is on modeling acoustic wavefield propagation and implementing imaging algorithms for breast cancer detection using ultrasound. As a starting point, we use an integral equation formulation, which can be used to solve both the forward and inverse problems. This thesis

  20. Human body region enhancement method based on Kinect infrared imaging

    Science.gov (United States)

    Yang, Lei; Fan, Yubo; Song, Xiaowei; Cai, Wenjing

    2016-10-01

    To effectively improve the low contrast of human body region in the infrared images, a combing method of several enhancement methods is utilized to enhance the human body region. Firstly, for the infrared images acquired by Kinect, in order to improve the overall contrast of the infrared images, an Optimal Contrast-Tone Mapping (OCTM) method with multi-iterations is applied to balance the contrast of low-luminosity infrared images. Secondly, to enhance the human body region better, a Level Set algorithm is employed to improve the contour edges of human body region. Finally, to further improve the human body region in infrared images, Laplacian Pyramid decomposition is adopted to enhance the contour-improved human body region. Meanwhile, the background area without human body region is processed by bilateral filtering to improve the overall effect. With theoretical analysis and experimental verification, the results show that the proposed method could effectively enhance the human body region of such infrared images.

  1. Imaging systems and methods for obtaining and using biometric information

    Science.gov (United States)

    McMakin, Douglas L [Richland, WA; Kennedy, Mike O [Richland, WA

    2010-11-30

    Disclosed herein are exemplary embodiments of imaging systems and methods of using such systems. In one exemplary embodiment, one or more direct images of the body of a clothed subject are received, and a motion signature is determined from the one or more images. In this embodiment, the one or more images show movement of the body of the subject over time, and the motion signature is associated with the movement of the subject's body. In certain implementations, the subject can be identified based at least in part on the motion signature. Imaging systems for performing any of the disclosed methods are also disclosed herein. Furthermore, the disclosed imaging, rendering, and analysis methods can be implemented, at least in part, as one or more computer-readable media comprising computer-executable instructions for causing a computer to perform the respective methods.

  2. Imaging method of brain surface anatomy structures using conventional T2-weighted MR images

    International Nuclear Information System (INIS)

    Hatanaka, Masahiko; Machida, Yoshio; Yoshida, Tadatoki; Katada, Kazuhiro.

    1992-01-01

    As a non-invasive technique for visualizing the brain surface structure by MRI, surface anatomy scanning (SAS) and the multislice SAS methods have been developed. Both techniques require additional MRI scanning to obtain images for the brain surface. In this paper, we report an alternative method to obtain the brain surface image using conventional T2-weighted multislice images without any additional scanning. The power calculation of the image pixel values, which is incorporated in the routine processing, has been applied in order to enhance the cerebrospinal fluid (CSF) contrast. We think that this method is one of practical approaches for imaging the surface anatomy of the brain. (author)

  3. Brain diagnosis with imaging methods: Psychical changes made visible

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    The First International Symposium on Imaging Methods in Psychiatry, held in May 1988 in Wuerzburg, very impressively has shown that imaging methods are on advance not only in medical diagnostics, but also in psychiatric diagnostics, where they already proved to be a valuable tool. (orig./MG) [de

  4. Segment and fit thresholding: a new method for image analysis applied to microarray and immunofluorescence data.

    Science.gov (United States)

    Ensink, Elliot; Sinha, Jessica; Sinha, Arkadeep; Tang, Huiyuan; Calderone, Heather M; Hostetter, Galen; Winter, Jordan; Cherba, David; Brand, Randall E; Allen, Peter J; Sempere, Lorenzo F; Haab, Brian B

    2015-10-06

    Experiments involving the high-throughput quantification of image data require algorithms for automation. A challenge in the development of such algorithms is to properly interpret signals over a broad range of image characteristics, without the need for manual adjustment of parameters. Here we present a new approach for locating signals in image data, called Segment and Fit Thresholding (SFT). The method assesses statistical characteristics of small segments of the image and determines the best-fit trends between the statistics. Based on the relationships, SFT identifies segments belonging to background regions; analyzes the background to determine optimal thresholds; and analyzes all segments to identify signal pixels. We optimized the initial settings for locating background and signal in antibody microarray and immunofluorescence data and found that SFT performed well over multiple, diverse image characteristics without readjustment of settings. When used for the automated analysis of multicolor, tissue-microarray images, SFT correctly found the overlap of markers with known subcellular localization, and it performed better than a fixed threshold and Otsu's method for selected images. SFT promises to advance the goal of full automation in image analysis.

  5. Radiopharmaceutical chelates and method of external imaging

    International Nuclear Information System (INIS)

    1976-01-01

    The preparation of the following chemicals is described: chelates of technetium-99m, cobalt-57, gallium-67, gallium-68, indium-111 or indium-113m and a substituted iminodiacetic acid or an 8-hydroxyquinoline useful as a radiopharmaceutical external imaging agent. The compounds described are suitable for intravenous injection, have an excellent in vivo stability and are good organ seekers. Tin(II) choride or other tin(II) compounds are used as chelating agents

  6. Soft Shadow Removal and Image Evaluation Methods

    OpenAIRE

    Gryka, M.

    2016-01-01

    High-level image manipulation techniques are in increasing demand as they allow users to intuitively edit photographs to achieve desired effects quickly. As opposed to low-level manipulations, which provide complete freedom, but also require specialized skills and significant effort, high-level editing operations, such as removing objects (inpainting), relighting and material editing, need to respect semantic constraints. As such they shift the burden from the user to the algorithm to only al...

  7. An FPGA-based heterogeneous image fusion system design method

    Science.gov (United States)

    Song, Le; Lin, Yu-chi; Chen, Yan-hua; Zhao, Mei-rong

    2011-08-01

    Taking the advantages of FPGA's low cost and compact structure, an FPGA-based heterogeneous image fusion platform is established in this study. Altera's Cyclone IV series FPGA is adopted as the core processor of the platform, and the visible light CCD camera and infrared thermal imager are used as the image-capturing device in order to obtain dualchannel heterogeneous video images. Tailor-made image fusion algorithms such as gray-scale weighted averaging, maximum selection and minimum selection methods are analyzed and compared. VHDL language and the synchronous design method are utilized to perform a reliable RTL-level description. Altera's Quartus II 9.0 software is applied to simulate and implement the algorithm modules. The contrast experiments of various fusion algorithms show that, preferably image quality of the heterogeneous image fusion can be obtained on top of the proposed system. The applied range of the different fusion algorithms is also discussed.

  8. Level set method for image segmentation based on moment competition

    Science.gov (United States)

    Min, Hai; Wang, Xiao-Feng; Huang, De-Shuang; Jin, Jing; Wang, Hong-Zhi; Li, Hai

    2015-05-01

    We propose a level set method for image segmentation which introduces the moment competition and weakly supervised information into the energy functional construction. Different from the region-based level set methods which use force competition, the moment competition is adopted to drive the contour evolution. Here, a so-called three-point labeling scheme is proposed to manually label three independent points (weakly supervised information) on the image. Then the intensity differences between the three points and the unlabeled pixels are used to construct the force arms for each image pixel. The corresponding force is generated from the global statistical information of a region-based method and weighted by the force arm. As a result, the moment can be constructed and incorporated into the energy functional to drive the evolving contour to approach the object boundary. In our method, the force arm can take full advantage of the three-point labeling scheme to constrain the moment competition. Additionally, the global statistical information and weakly supervised information are successfully integrated, which makes the proposed method more robust than traditional methods for initial contour placement and parameter setting. Experimental results with performance analysis also show the superiority of the proposed method on segmenting different types of complicated images, such as noisy images, three-phase images, images with intensity inhomogeneity, and texture images.

  9. Analysis of live cell images: Methods, tools and opportunities.

    Science.gov (United States)

    Nketia, Thomas A; Sailem, Heba; Rohde, Gustavo; Machiraju, Raghu; Rittscher, Jens

    2017-02-15

    Advances in optical microscopy, biosensors and cell culturing technologies have transformed live cell imaging. Thanks to these advances live cell imaging plays an increasingly important role in basic biology research as well as at all stages of drug development. Image analysis methods are needed to extract quantitative information from these vast and complex data sets. The aim of this review is to provide an overview of available image analysis methods for live cell imaging, in particular required preprocessing image segmentation, cell tracking and data visualisation methods. The potential opportunities recent advances in machine learning, especially deep learning, and computer vision provide are being discussed. This review includes overview of the different available software packages and toolkits. Copyright © 2017. Published by Elsevier Inc.

  10. Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis. A promising imaging biomarker as an alternative to gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Barendregt, Anouk M.; Gulik, E.C. van [Academic Medical Center/University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center/University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital, Amsterdam (Netherlands); Lavini, Cristina; Nusman, Charlotte M.; Hemke, Robert; Maas, Mario [Academic Medical Center/University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Berg, J.M. van den; Schonenberg-Meinema, Dieneke; Kuijpers, Taco W. [Academic Medical Center/University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital, Amsterdam (Netherlands); Dolman, Koert M. [Reade, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis West, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis Oost, Department of Pediatric Rheumatology, Amsterdam (Netherlands)

    2017-11-15

    To compare dynamic-contrast-enhanced MRI (DCE) and diffusion-weighted imaging (DWI) in quantifying synovial inflammation in juvenile idiopathic arthritis (JIA). Regions of interest (ROI) were drawn in the synovium of JIA patients on T1 DCE and T2 DWI, followed by extraction of the maximum enhancement (ME), maximum initial slope (MIS), time to peak (TTP), % of different time intensity curve shapes (TIC) and apparent diffusion coefficient (ADC) of the ROIs. Mann-Whitney-U test was used for comparing parameters between MRI-active and -inactive patients (defined by the juvenile arthritis MRI scoring system). Spearman's rank was used to analyse the correlation between DCE and DWI. Thirty-five JIA patients (18 MRI active and 17 MRI inactive) were included. Median age was 13.1 years and 71% were female. ME, MIS, TTP, % TIC 5 and ADC were significantly different in MRI-active versus MRI-inactive JIA with median ADC 1.49 x 10{sup -3} mm{sup 2}/s in MRI-active and 1.25 x 10{sup -3} mm{sup 2}/s in MRI-inactive JIA, p = 0.001, 95% confidence interval of difference in medians =0.11-0.53 x 10{sup -3} mm{sup 2}/s. ADC correlated to ME, MIS and TIC 5 shapes (r = 0.62, r = 0.45, r = -0.51, respectively, all p < 0.05). Similar to DCE parameters, DWI-derived ADC is significantly different in MRI-active JIA as compared to MRI-inactive JIA. The non-invasiveness of DWI combined with its possibility to detect synovial inflammation shows the potential of DWI. (orig.)

  11. Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis. A promising imaging biomarker as an alternative to gadolinium-based contrast agents

    International Nuclear Information System (INIS)

    Barendregt, Anouk M.; Gulik, E.C. van; Lavini, Cristina; Nusman, Charlotte M.; Hemke, Robert; Maas, Mario; Berg, J.M. van den; Schonenberg-Meinema, Dieneke; Kuijpers, Taco W.; Dolman, Koert M.

    2017-01-01

    To compare dynamic-contrast-enhanced MRI (DCE) and diffusion-weighted imaging (DWI) in quantifying synovial inflammation in juvenile idiopathic arthritis (JIA). Regions of interest (ROI) were drawn in the synovium of JIA patients on T1 DCE and T2 DWI, followed by extraction of the maximum enhancement (ME), maximum initial slope (MIS), time to peak (TTP), % of different time intensity curve shapes (TIC) and apparent diffusion coefficient (ADC) of the ROIs. Mann-Whitney-U test was used for comparing parameters between MRI-active and -inactive patients (defined by the juvenile arthritis MRI scoring system). Spearman's rank was used to analyse the correlation between DCE and DWI. Thirty-five JIA patients (18 MRI active and 17 MRI inactive) were included. Median age was 13.1 years and 71% were female. ME, MIS, TTP, % TIC 5 and ADC were significantly different in MRI-active versus MRI-inactive JIA with median ADC 1.49 x 10 -3 mm 2 /s in MRI-active and 1.25 x 10 -3 mm 2 /s in MRI-inactive JIA, p = 0.001, 95% confidence interval of difference in medians =0.11-0.53 x 10 -3 mm 2 /s. ADC correlated to ME, MIS and TIC 5 shapes (r = 0.62, r = 0.45, r = -0.51, respectively, all p < 0.05). Similar to DCE parameters, DWI-derived ADC is significantly different in MRI-active JIA as compared to MRI-inactive JIA. The non-invasiveness of DWI combined with its possibility to detect synovial inflammation shows the potential of DWI. (orig.)

  12. Quantitative Analysis of Range Image Patches by NEB Method

    Directory of Open Access Journals (Sweden)

    Wang Wen

    2017-01-01

    Full Text Available In this paper we analyze sampled high dimensional data with the NEB method from a range image database. Select a large random sample of log-valued, high contrast, normalized, 8×8 range image patches from the Brown database. We make a density estimator and we establish 1-dimensional cell complexes from the range image patch data. We find topological properties of 8×8 range image patches, prove that there exist two types of subsets of 8×8 range image patches modelled as a circle.

  13. New Finger Biometric Method Using Near Infrared Imaging

    Science.gov (United States)

    Lee, Eui Chul; Jung, Hyunwoo; Kim, Daeyeoul

    2011-01-01

    In this paper, we propose a new finger biometric method. Infrared finger images are first captured, and then feature extraction is performed using a modified Gaussian high-pass filter through binarization, local binary pattern (LBP), and local derivative pattern (LDP) methods. Infrared finger images include the multimodal features of finger veins and finger geometries. Instead of extracting each feature using different methods, the modified Gaussian high-pass filter is fully convolved. Therefore, the extracted binary patterns of finger images include the multimodal features of veins and finger geometries. Experimental results show that the proposed method has an error rate of 0.13%. PMID:22163741

  14. Image Classification Workflow Using Machine Learning Methods

    Science.gov (United States)

    Christoffersen, M. S.; Roser, M.; Valadez-Vergara, R.; Fernández-Vega, J. A.; Pierce, S. A.; Arora, R.

    2016-12-01

    Recent increases in the availability and quality of remote sensing datasets have fueled an increasing number of scientifically significant discoveries based on land use classification and land use change analysis. However, much of the software made to work with remote sensing data products, specifically multispectral images, is commercial and often prohibitively expensive. The free to use solutions that are currently available come bundled up as small parts of much larger programs that are very susceptible to bugs and difficult to install and configure. What is needed is a compact, easy to use set of tools to perform land use analysis on multispectral images. To address this need, we have developed software using the Python programming language with the sole function of land use classification and land use change analysis. We chose Python to develop our software because it is relatively readable, has a large body of relevant third party libraries such as GDAL and Spectral Python, and is free to install and use on Windows, Linux, and Macintosh operating systems. In order to test our classification software, we performed a K-means unsupervised classification, Gaussian Maximum Likelihood supervised classification, and a Mahalanobis Distance based supervised classification. The images used for testing were three Landsat rasters of Austin, Texas with a spatial resolution of 60 meters for the years of 1984 and 1999, and 30 meters for the year 2015. The testing dataset was easily downloaded using the Earth Explorer application produced by the USGS. The software should be able to perform classification based on any set of multispectral rasters with little to no modification. Our software makes the ease of land use classification using commercial software available without an expensive license.

  15. THE EFFECT OF IMAGE ENHANCEMENT METHODS DURING FEATURE DETECTION AND MATCHING OF THERMAL IMAGES

    Directory of Open Access Journals (Sweden)

    O. Akcay

    2017-05-01

    Full Text Available A successful image matching is essential to provide an automatic photogrammetric process accurately. Feature detection, extraction and matching algorithms have performed on the high resolution images perfectly. However, images of cameras, which are equipped with low-resolution thermal sensors are problematic with the current algorithms. In this paper, some digital image processing techniques were applied to the low-resolution images taken with Optris PI 450 382 x 288 pixel optical resolution lightweight thermal camera to increase extraction and matching performance. Image enhancement methods that adjust low quality digital thermal images, were used to produce more suitable images for detection and extraction. Three main digital image process techniques: histogram equalization, high pass and low pass filters were considered to increase the signal-to-noise ratio, sharpen image, remove noise, respectively. Later on, the pre-processed images were evaluated using current image detection and feature extraction methods Maximally Stable Extremal Regions (MSER and Speeded Up Robust Features (SURF algorithms. Obtained results showed that some enhancement methods increased number of extracted features and decreased blunder errors during image matching. Consequently, the effects of different pre-process techniques were compared in the paper.

  16. Multi-band Image Registration Method Based on Fourier Transform

    Institute of Scientific and Technical Information of China (English)

    庹红娅; 刘允才

    2004-01-01

    This paper presented a registration method based on Fourier transform for multi-band images which is involved in translation and small rotation. Although different band images differ a lot in the intensity and features,they contain certain common information which we can exploit. A model was given that the multi-band images have linear correlations under the least-square sense. It is proved that the coefficients have no effect on the registration progress if two images have linear correlations. Finally, the steps of the registration method were proposed. The experiments show that the model is reasonable and the results are satisfying.

  17. Image Mosaic Method Based on SIFT Features of Line Segment

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    2014-01-01

    Full Text Available This paper proposes a novel image mosaic method based on SIFT (Scale Invariant Feature Transform feature of line segment, aiming to resolve incident scaling, rotation, changes in lighting condition, and so on between two images in the panoramic image mosaic process. This method firstly uses Harris corner detection operator to detect key points. Secondly, it constructs directed line segments, describes them with SIFT feature, and matches those directed segments to acquire rough point matching. Finally, Ransac method is used to eliminate wrong pairs in order to accomplish image mosaic. The results from experiment based on four pairs of images show that our method has strong robustness for resolution, lighting, rotation, and scaling.

  18. Development of motion image prediction method using principal component analysis

    International Nuclear Information System (INIS)

    Chhatkuli, Ritu Bhusal; Demachi, Kazuyuki; Kawai, Masaki; Sakakibara, Hiroshi; Kamiaka, Kazuma

    2012-01-01

    Respiratory motion can induce the limit in the accuracy of area irradiated during lung cancer radiation therapy. Many methods have been introduced to minimize the impact of healthy tissue irradiation due to the lung tumor motion. The purpose of this research is to develop an algorithm for the improvement of image guided radiation therapy by the prediction of motion images. We predict the motion images by using principal component analysis (PCA) and multi-channel singular spectral analysis (MSSA) method. The images/movies were successfully predicted and verified using the developed algorithm. With the proposed prediction method it is possible to forecast the tumor images over the next breathing period. The implementation of this method in real time is believed to be significant for higher level of tumor tracking including the detection of sudden abdominal changes during radiation therapy. (author)

  19. Iterative methods for dose reduction and image enhancement in tomography

    Science.gov (United States)

    Miao, Jianwei; Fahimian, Benjamin Pooya

    2012-09-18

    A system and method for creating a three dimensional cross sectional image of an object by the reconstruction of its projections that have been iteratively refined through modification in object space and Fourier space is disclosed. The invention provides systems and methods for use with any tomographic imaging system that reconstructs an object from its projections. In one embodiment, the invention presents a method to eliminate interpolations present in conventional tomography. The method has been experimentally shown to provide higher resolution and improved image quality parameters over existing approaches. A primary benefit of the method is radiation dose reduction since the invention can produce an image of a desired quality with a fewer number projections than seen with conventional methods.

  20. Thresholding methods for PET imaging: A review

    International Nuclear Information System (INIS)

    Dewalle-Vignion, A.S.; Betrouni, N.; Huglo, D.; Vermandel, M.; Dewalle-Vignion, A.S.; Hossein-Foucher, C.; Huglo, D.; Vermandel, M.; Dewalle-Vignion, A.S.; Hossein-Foucher, C.; Huglo, D.; Vermandel, M.; El Abiad, A.

    2010-01-01

    This work deals with positron emission tomography segmentation methods for tumor volume determination. We propose a state of art techniques based on fixed or adaptive threshold. Methods found in literature are analysed with an objective point of view on their methodology, advantages and limitations. Finally, a comparative study is presented. (authors)

  1. Generalized Row-Action Methods for Tomographic Imaging

    DEFF Research Database (Denmark)

    Andersen, Martin Skovgaard; Hansen, Per Christian

    2014-01-01

    Row-action methods play an important role in tomographic image reconstruction. Many such methods can be viewed as incremental gradient methods for minimizing a sum of a large number of convex functions, and despite their relatively poor global rate of convergence, these methods often exhibit fast...... initial convergence which is desirable in applications where a low-accuracy solution is acceptable. In this paper, we propose relaxed variants of a class of incremental proximal gradient methods, and these variants generalize many existing row-action methods for tomographic imaging. Moreover, they allow...

  2. A Method of Road Extraction from High-resolution Remote Sensing Images Based on Shape Features

    Directory of Open Access Journals (Sweden)

    LEI Xiaoqi

    2016-02-01

    Full Text Available Road extraction from high-resolution remote sensing image is an important and difficult task.Since remote sensing images include complicated information,the methods that extract roads by spectral,texture and linear features have certain limitations.Also,many methods need human-intervention to get the road seeds(semi-automatic extraction,which have the great human-dependence and low efficiency.The road-extraction method,which uses the image segmentation based on principle of local gray consistency and integration shape features,is proposed in this paper.Firstly,the image is segmented,and then the linear and curve roads are obtained by using several object shape features,so the method that just only extract linear roads are rectified.Secondly,the step of road extraction is carried out based on the region growth,the road seeds are automatic selected and the road network is extracted.Finally,the extracted roads are regulated by combining the edge information.In experiments,the images that including the better gray uniform of road and the worse illuminated of road surface were chosen,and the results prove that the method of this study is promising.

  3. Image based method for aberration measurement of lithographic tools

    Science.gov (United States)

    Xu, Shuang; Tao, Bo; Guo, Yongxing; Li, Gongfa

    2018-01-01

    Information of lens aberration of lithographic tools is important as it directly affects the intensity distribution in the image plane. Zernike polynomials are commonly used for a mathematical description of lens aberrations. Due to the advantage of lower cost and easier implementation of tools, image based measurement techniques have been widely used. Lithographic tools are typically partially coherent systems that can be described by a bilinear model, which entails time consuming calculations and does not lend a simple and intuitive relationship between lens aberrations and the resulted images. Previous methods for retrieving lens aberrations in such partially coherent systems involve through-focus image measurements and time-consuming iterative algorithms. In this work, we propose a method for aberration measurement in lithographic tools, which only requires measuring two images of intensity distribution. Two linear formulations are derived in matrix forms that directly relate the measured images to the unknown Zernike coefficients. Consequently, an efficient non-iterative solution is obtained.

  4. A NDVI assisted remote sensing image adaptive scale segmentation method

    Science.gov (United States)

    Zhang, Hong; Shen, Jinxiang; Ma, Yanmei

    2018-03-01

    Multiscale segmentation of images can effectively form boundaries of different objects with different scales. However, for the remote sensing image which widely coverage with complicated ground objects, the number of suitable segmentation scales, and each of the scale size is still difficult to be accurately determined, which severely restricts the rapid information extraction of the remote sensing image. A great deal of experiments showed that the normalized difference vegetation index (NDVI) can effectively express the spectral characteristics of a variety of ground objects in remote sensing images. This paper presents a method using NDVI assisted adaptive segmentation of remote sensing images, which segment the local area by using NDVI similarity threshold to iteratively select segmentation scales. According to the different regions which consist of different targets, different segmentation scale boundaries could be created. The experimental results showed that the adaptive segmentation method based on NDVI can effectively create the objects boundaries for different ground objects of remote sensing images.

  5. An efficient method for facial component detection in thermal images

    Science.gov (United States)

    Paul, Michael; Blanik, Nikolai; Blazek, Vladimir; Leonhardt, Steffen

    2015-04-01

    A method to detect certain regions in thermal images of human faces is presented. In this approach, the following steps are necessary to locate the periorbital and the nose regions: First, the face is segmented from the background by thresholding and morphological filtering. Subsequently, a search region within the face, around its center of mass, is evaluated. Automatically computed temperature thresholds are used per subject and image or image sequence to generate binary images, in which the periorbital regions are located by integral projections. Then, the located positions are used to approximate the nose position. It is possible to track features in the located regions. Therefore, these regions are interesting for different applications like human-machine interaction, biometrics and biomedical imaging. The method is easy to implement and does not rely on any training images or templates. Furthermore, the approach saves processing resources due to simple computations and restricted search regions.

  6. New diffusion imaging method with a single acquisition sequence

    International Nuclear Information System (INIS)

    Melki, Ph.S.; Bittoun, J.; Lefevre, J.E.

    1987-01-01

    The apparent diffusion coefficient (ADC) is related to the molecular diffusion coefficient and to physiologic information: microcirculation in the capillary network, incoherent slow flow, and restricted diffusion. The authors present a new MR imaging sequence that yields computed ADC images in only one acquisition of 9-minutes with a 1.5-T imager (GE Signa). Compared to the previous method, this sequence is at least two times faster and thus can be used as a routine examination to supplement T1-, T2-, and density-weighted images. The method was assessed by measurement of the molecular diffusion in liquids, and the first clinical images obtained in neurologic diseases demonstrate its efficiency for clinical investigation. The possibility of separately imaging diffusion and perfusion is supported by an algorithm

  7. Profiling pleural effusion cells by a diffraction imaging method

    Science.gov (United States)

    Al-Qaysi, Safaa; Hong, Heng; Wen, Yuhua; Lu, Jun Q.; Feng, Yuanming; Hu, Xin-Hua

    2018-02-01

    Assay of cells in pleural effusion (PE) is an important means of disease diagnosis. Conventional cytology of effusion samples, however, has low sensitivity and depends heavily on the expertise of cytopathologists. We applied a polarization diffraction imaging flow cytometry method on effusion cells to investigate their features. Diffraction imaging of the PE cell samples has been performed on 6000 to 12000 cells for each effusion cell sample of three patients. After prescreening to remove images by cellular debris and aggregated non-cellular particles, the image textures were extracted with a gray level co-occurrence matrix (GLCM) algorithm. The distribution of the imaged cells in the GLCM parameters space was analyzed by a Gaussian Mixture Model (GMM) to determine the number of clusters among the effusion cells. These results yield insight on textural features of diffraction images and related cellular morphology in effusion samples and can be used toward the development of a label-free method for effusion cells assay.

  8. Imaging methods for detection of infectious foci

    International Nuclear Information System (INIS)

    Couret, I.; Rossi, M.; Weinemann, P.; Moretti, J.L.

    1993-01-01

    Several tracers can be used for imaging infection. None is a worthwhile agent for all infectious foci, but each one has preferential applications, depending on its uptake mechanism by the infectious and/or inflammatory focus. Autologous leucocytes labeled in vitro with indium-111 (In-111) or with technetium-99-hexamethylpropyleneamine oxime (Tc-99m HMPAO) were applied with success in the detection of peripheral bone infection, focal vascular graft infection and inflammatory bowel disease. Labeling with In-111 is of interest in chronic bone infection, while labeling with Tc-99m HMPAO gets the advantage of a better dosimetry and imaging. The interest of in vivo labeled leucocytes with a Tc-99m labeled monoclonal antigranulocyte antibody anti-NCA 95 (BW 250/183) was proved in the same principal type of infectious foci than in vitro labeled leucocytes. Sites of chronic infection in the spine and the pelvis, whether active or healed, appear as photopenic defects on both in vitro labeled leucocytes and Tc-99m monoclonal antigranulocyte antibody (BW 250/183) scintigraphies. With gallium-67 results showed a high sensitivity with a low specificity. This tracer demonstrated good performance to delineate foci of infectious spondylitis. In-111 and Tc-99m labeled polyclonal human immunoglobulin (HIG) was applied with success in the assessment of various infectious foci, particularly in chronic sepsis. As labeled leucocytes, labeled HIG showed cold defects in infectious sepsis of the spine. Research in nuclear medicine is very active in the development of more specific tracers of infection, mainly involved in Tc-99m or In-111 labeled chemotactic peptides, antigranulocyte antibody fragments, antibiotic derivatives and interleukins. (authors). 70 refs

  9. Optimized computational imaging methods for small-target sensing in lens-free holographic microscopy

    Science.gov (United States)

    Xiong, Zhen; Engle, Isaiah; Garan, Jacob; Melzer, Jeffrey E.; McLeod, Euan

    2018-02-01

    Lens-free holographic microscopy is a promising diagnostic approach because it is cost-effective, compact, and suitable for point-of-care applications, while providing high resolution together with an ultra-large field-of-view. It has been applied to biomedical sensing, where larger targets like eukaryotic cells, bacteria, or viruses can be directly imaged without labels, and smaller targets like proteins or DNA strands can be detected via scattering labels like micro- or nano-spheres. Automated image processing routines can count objects and infer target concentrations. In these sensing applications, sensitivity and specificity are critically affected by image resolution and signal-to-noise ratio (SNR). Pixel super-resolution approaches have been shown to boost resolution and SNR by synthesizing a high-resolution image from multiple, partially redundant, low-resolution images. However, there are several computational methods that can be used to synthesize the high-resolution image, and previously, it has been unclear which methods work best for the particular case of small-particle sensing. Here, we quantify the SNR achieved in small-particle sensing using regularized gradient-descent optimization method, where the regularization is based on cardinal-neighbor differences, Bayer-pattern noise reduction, or sparsity in the image. In particular, we find that gradient-descent with sparsity-based regularization works best for small-particle sensing. These computational approaches were evaluated on images acquired using a lens-free microscope that we assembled from an off-the-shelf LED array and color image sensor. Compared to other lens-free imaging systems, our hardware integration, calibration, and sample preparation are particularly simple. We believe our results will help to enable the best performance in lens-free holographic sensing.

  10. Advances and Perspectives in Chemical Imaging in Cellular Environments Using Electrochemical Methods

    Directory of Open Access Journals (Sweden)

    Robert A. Lazenby

    2018-05-01

    Full Text Available This review discusses a broad range of recent advances (2013–2017 in chemical imaging using electrochemical methods, with a particular focus on techniques that have been applied to study cellular processes, or techniques that show promise for use in this field in the future. Non-scanning techniques such as microelectrode arrays (MEAs offer high time-resolution (<10 ms imaging; however, at reduced spatial resolution. In contrast, scanning electrochemical probe microscopies (SEPMs offer higher spatial resolution (as low as a few nm per pixel imaging, with images collected typically over many minutes. Recent significant research efforts to improve the spatial resolution of SEPMs using nanoscale probes and to improve the temporal resolution using fast scanning have resulted in movie (multiple frame imaging with frame rates as low as a few seconds per image. Many SEPM techniques lack chemical specificity or have poor selectivity (defined by the choice of applied potential for redox-active species. This can be improved using multifunctional probes, ion-selective electrodes and tip-integrated biosensors, although additional effort may be required to preserve sensor performance after miniaturization of these probes. We discuss advances to the field of electrochemical imaging, and technological developments which are anticipated to extend the range of processes that can be studied. This includes imaging cellular processes with increased sensor selectivity and at much improved spatiotemporal resolution than has been previously customary.

  11. The best printing methods to print satellite images

    OpenAIRE

    G.A. Yousif; R.Sh. Mohamed

    2011-01-01

    Printing systems operate in general as a system of color its color scale is limited as compared with the system color satellite images. Satellite image is building from very small cell named pixel, which represents the picture element and the unity of color when the image is displayed on the screen, this unit becomes lesser in size and called screen point. This unit posseses different size and shape from the method of printing to another, depending on the output resolution, tools and material...

  12. Mathematical methods in time series analysis and digital image processing

    CERN Document Server

    Kurths, J; Maass, P; Timmer, J

    2008-01-01

    The aim of this volume is to bring together research directions in theoretical signal and imaging processing developed rather independently in electrical engineering, theoretical physics, mathematics and the computer sciences. In particular, mathematically justified algorithms and methods, the mathematical analysis of these algorithms, and methods as well as the investigation of connections between methods from time series analysis and image processing are reviewed. An interdisciplinary comparison of these methods, drawing upon common sets of test problems from medicine and geophysical/enviromental sciences, is also addressed. This volume coherently summarizes work carried out in the field of theoretical signal and image processing. It focuses on non-linear and non-parametric models for time series as well as on adaptive methods in image processing.

  13. Fingerprint image reconstruction for swipe sensor using Predictive Overlap Method

    Directory of Open Access Journals (Sweden)

    Mardiansyah Ahmad Zafrullah

    2018-01-01

    Full Text Available Swipe sensor is one of many biometric authentication sensor types that widely applied to embedded devices. The sensor produces an overlap on every pixel block of the image, so the picture requires a reconstruction process before heading to the feature extraction process. Conventional reconstruction methods require extensive computation, causing difficult to apply to embedded devices that have limited computing process. In this paper, image reconstruction is proposed using predictive overlap method, which determines the image block shift from the previous set of change data. The experiments were performed using 36 images generated by a swipe sensor with 128 x 8 pixels size of the area, where each image has an overlap in each block. The results reveal computation can increase up to 86.44% compared with conventional methods, with accuracy decreasing to 0.008% in average.

  14. Texture recognition of medical images with the ICM method

    International Nuclear Information System (INIS)

    Kinser, Jason M.; Wang Guisong

    2004-01-01

    The Integrated Cortical Model (ICM) is based upon several models of the mammalian visual cortex and produces pulse images over several iterations. These pulse images tend to isolate segments, edges, and textures that are inherent in the input image. To create a texture recognition engine the pulse spectrum of individual pixels are collected and used to develop a recognition library. Recognition is performed by comparing pulse spectra of unclassified regions of images with the known regions. Because signatures are smaller than images, signature-based computation is quite efficient and parasites can be recognized quickly. The precision of this method depends on the representative of signatures and classification. Our experiment results support the theoretical findings and show perspectives of practical applications of ICM-based method. The advantage of ICM method is using signatures to represent objects. ICM can extract the internal features of objects and represent them with signatures. Signature classification is critical for the precision of recognition

  15. Some selected quantitative methods of thermal image analysis in Matlab.

    Science.gov (United States)

    Koprowski, Robert

    2016-05-01

    The paper presents a new algorithm based on some selected automatic quantitative methods for analysing thermal images. It shows the practical implementation of these image analysis methods in Matlab. It enables to perform fully automated and reproducible measurements of selected parameters in thermal images. The paper also shows two examples of the use of the proposed image analysis methods for the area of ​​the skin of a human foot and face. The full source code of the developed application is also provided as an attachment. The main window of the program during dynamic analysis of the foot thermal image. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Matrix-based image reconstruction methods for tomography

    International Nuclear Information System (INIS)

    Llacer, J.; Meng, J.D.

    1984-10-01

    Matrix methods of image reconstruction have not been used, in general, because of the large size of practical matrices, ill condition upon inversion and the success of Fourier-based techniques. An exception is the work that has been done at the Lawrence Berkeley Laboratory for imaging with accelerated radioactive ions. An extension of that work into more general imaging problems shows that, with a correct formulation of the problem, positron tomography with ring geometries results in well behaved matrices which can be used for image reconstruction with no distortion of the point response in the field of view and flexibility in the design of the instrument. Maximum Likelihood Estimator methods of reconstruction, which use the system matrices tailored to specific instruments and do not need matrix inversion, are shown to result in good preliminary images. A parallel processing computer structure based on multiple inexpensive microprocessors is proposed as a system to implement the matrix-MLE methods. 14 references, 7 figures

  17. Liposomal solubilization of new 3-hydroxy-quinolinone derivatives with promising anticancer activity: a screening method to identify maximum incorporation capacity

    DEFF Research Database (Denmark)

    Di Cagno, Massimiliano; Styskala, Jakub; Hlaváč, Jan

    2011-01-01

    Four new 3-hydroxy-quinolinone derivatives with promising anticancer activity could be solubilized using liposomes as vehicle to an extent that allows their in vitro and in vivo testing without use of toxic solvent(s). A screening method to identify the maximum incorporation capacity of hydrophobic......, resulting in a 200-500-fold increase in apparent solubility. Drug-to-lipid ratios in the range of 2-5 µg/mg were obtained. Interestingly, the four quinolinone derivatives have shown different association tendencies with liposomes, probably due to the physicochemical properties of the different group bonded...

  18. Method and apparatus for improving the alignment of radiographic images

    International Nuclear Information System (INIS)

    Schuller, P.D.; Hatcher, D.C.; Caelli, T.M.; Eggert, F.M.; Yuzyk, J.

    1991-01-01

    This invention relates generally to the field of radiology, and has to do particularly with a method and apparatus for improving the alignment of radiographic images taken at different times of the same tissue structure, so that the images can be sequentially shown in aligned condition, whereby changes in the structure can be noted. (author). 10 figs

  19. Method for analysis of failure of material employing imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, H.J.; Wellington, S.L.; de Waal, J.A.

    1989-12-05

    This patent describes a method for determining at least one preselected property of a sample of material employing an imaging apparatus. It comprises: imaging the sample during the application of known preselected forces to the sample, and determining density in the sample responsive to the preselected forces.

  20. An attenuation correction method for PET/CT images

    International Nuclear Information System (INIS)

    Ue, Hidenori; Yamazaki, Tomohiro; Haneishi, Hideaki

    2006-01-01

    In PET/CT systems, accurate attenuation correction can be achieved by creating an attenuation map from an X-ray CT image. On the other hand, respiratory-gated PET acquisition is an effective method for avoiding motion blurring of the thoracic and abdominal organs caused by respiratory motion. In PET/CT systems employing respiratory-gated PET, using an X-ray CT image acquired during breath-holding for attenuation correction may have a large effect on the voxel values, especially in regions with substantial respiratory motion. In this report, we propose an attenuation correction method in which, as the first step, a set of respiratory-gated PET images is reconstructed without attenuation correction, as the second step, the motion of each phase PET image from the PET image in the same phase as the CT acquisition timing is estimated by the previously proposed method, as the third step, the CT image corresponding to each respiratory phase is generated from the original CT image by deformation according to the motion vector maps, and as the final step, attenuation correction using these CT images and reconstruction are performed. The effectiveness of the proposed method was evaluated using 4D-NCAT phantoms, and good stability of the voxel values near the diaphragm was observed. (author)

  1. Method and Apparatus for Computed Imaging Backscatter Radiography

    Science.gov (United States)

    Shedlock, Daniel (Inventor); Meng, Christopher (Inventor); Sabri, Nissia (Inventor); Dugan, Edward T. (Inventor); Jacobs, Alan M. (Inventor)

    2013-01-01

    Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion.

  2. Image segmentation with a finite element method

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    regularization results, make possible to imagine a finite element resolution method.In a first time, the Mumford-Shah functional is introduced and some existing results are quoted. Then, a discrete formulation for the Mumford-Shah problem is proposed and its $\\Gamma$-convergence is proved. Finally, some...

  3. Method and apparatus for producing tomographic images

    International Nuclear Information System (INIS)

    Annis, M.

    1989-01-01

    A device useful in producing a tomographic image of a selected slice of an object to be examined is described comprising: a source of penetrating radiation, sweep means for forming energy from the source into a pencil beam and repeatedly sweeping the pencil beam over a line in space to define a sweep plane, first means for supporting an object to be examined so that the pencil beam intersections the object along a path passing through the object and the selected slice, line collimating means for filtering radiation scattered by the object, the line collimating means having a field of view which intersects and sweep plane in a bounded line so that the line collimating means passes only radiation scattered by elementary volumes of the object lying along the bounded line, and line collimating means including a plurality of channels such substantially planar in form to collectively define the field of view, the channels oriented so that pencil beam sweeps along the bounded line as a function of time, and radiation detector means responsive to radiation passed by the line collimating means

  4. Method for imaging pulmonary arterial hypoplasia

    International Nuclear Information System (INIS)

    Triantafillou, M.

    2000-01-01

    Full text: Pulmonary hypoplasia represents an incomplete development of the lung, resulting in the reduction of distended lung volume. This is associated with small or absent number of airway divisions, alveoli, arteries and veins. Unilateral pulmonary Hypoplasia is often asymptomatic and may be demonstrated as a hypodense lung on a chest X-ray. Computer Tomography (CT) scanning would show anatomical detail and proximal vessels. Magnetic Resonance Imaging (MRI) will show no more detail than which the CT scan has already demonstrated. It is, also, difficult to visualise collateral vessels from systemic and/or bronchial vessels on both these modalities. Pulmonary Angiography would give the definitive answer, but it is time consuming and has significant risks associated with the procedure. There are high costs associated with these modalities. Nuclear Medicine Ventilation/Perfusion (V/Q) scan performed on these patients would demonstrate diminished ventilation due to reduced lung volume and absence of perfusion to the hypoplastic lung. To date, we have performed V/Q lung scan on two children in our department. Both cases demonstrate diminished ventilation with no perfusion to the hypoplastic lung. Though the gold standard is Pulmonary Angiography, V/Q scanning is cost effective, less time consuming and a non invasive procedure that can be performed as an outpatient. It is accurate as it demonstrates absent lung perfusion, confirming the patient has pulmonary arterial hypoplasia. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  5. IMPROVING THE QUALITY OF NEAR-INFRARED IMAGING OF IN VIVOBLOOD VESSELS USING IMAGE FUSION METHODS

    DEFF Research Database (Denmark)

    Jensen, Andreas Kryger; Savarimuthu, Thiusius Rajeeth; Sørensen, Anders Stengaard

    2009-01-01

    We investigate methods for improving the visual quality of in vivo images of blood vessels in the human forearm. Using a near-infrared light source and a dual CCD chip camera system capable of capturing images at visual and nearinfrared spectra, we evaluate three fusion methods in terms...... of their capability of enhancing the blood vessels while preserving the spectral signature of the original color image. Furthermore, we investigate a possibility of removing hair in the images using a fusion rule based on the "a trous" stationary wavelet decomposition. The method with the best overall performance...... with both speed and quality in mind is the Intensity Injection method. Using the developed system and the methods presented in this article, it is possible to create images of high visual quality with highly emphasized blood vessels....

  6. Image quality enhancement in low-light-level ghost imaging using modified compressive sensing method

    Science.gov (United States)

    Shi, Xiaohui; Huang, Xianwei; Nan, Suqin; Li, Hengxing; Bai, Yanfeng; Fu, Xiquan

    2018-04-01

    Detector noise has a significantly negative impact on ghost imaging at low light levels, especially for existing recovery algorithm. Based on the characteristics of the additive detector noise, a method named modified compressive sensing ghost imaging is proposed to reduce the background imposed by the randomly distributed detector noise at signal path. Experimental results show that, with an appropriate choice of threshold value, modified compressive sensing ghost imaging algorithm can dramatically enhance the contrast-to-noise ratio of the object reconstruction significantly compared with traditional ghost imaging and compressive sensing ghost imaging methods. The relationship between the contrast-to-noise ratio of the reconstruction image and the intensity ratio (namely, the average signal intensity to average noise intensity ratio) for the three reconstruction algorithms are also discussed. This noise suppression imaging technique will have great applications in remote-sensing and security areas.

  7. A method of fast mosaic for massive UAV images

    Science.gov (United States)

    Xiang, Ren; Sun, Min; Jiang, Cheng; Liu, Lei; Zheng, Hui; Li, Xiaodong

    2014-11-01

    With the development of UAV technology, UAVs are used widely in multiple fields such as agriculture, forest protection, mineral exploration, natural disaster management and surveillances of public security events. In contrast of traditional manned aerial remote sensing platforms, UAVs are cheaper and more flexible to use. So users can obtain massive image data with UAVs, but this requires a lot of time to process the image data, for example, Pix4UAV need approximately 10 hours to process 1000 images in a high performance PC. But disaster management and many other fields require quick respond which is hard to realize with massive image data. Aiming at improving the disadvantage of high time consumption and manual interaction, in this article a solution of fast UAV image stitching is raised. GPS and POS data are used to pre-process the original images from UAV, belts and relation between belts and images are recognized automatically by the program, in the same time useless images are picked out. This can boost the progress of finding match points between images. Levenberg-Marquard algorithm is improved so that parallel computing can be applied to shorten the time of global optimization notably. Besides traditional mosaic result, it can also generate superoverlay result for Google Earth, which can provide a fast and easy way to show the result data. In order to verify the feasibility of this method, a fast mosaic system of massive UAV images is developed, which is fully automated and no manual interaction is needed after original images and GPS data are provided. A test using 800 images of Kelan River in Xinjiang Province shows that this system can reduce 35%-50% time consumption in contrast of traditional methods, and increases respond speed of UAV image processing rapidly.

  8. DCS-SVM: a novel semi-automated method for human brain MR image segmentation.

    Science.gov (United States)

    Ahmadvand, Ali; Daliri, Mohammad Reza; Hajiali, Mohammadtaghi

    2017-11-27

    In this paper, a novel method is proposed which appropriately segments magnetic resonance (MR) brain images into three main tissues. This paper proposes an extension of our previous work in which we suggested a combination of multiple classifiers (CMC)-based methods named dynamic classifier selection-dynamic local training local Tanimoto index (DCS-DLTLTI) for MR brain image segmentation into three main cerebral tissues. This idea is used here and a novel method is developed that tries to use more complex and accurate classifiers like support vector machine (SVM) in the ensemble. This work is challenging because the CMC-based methods are time consuming, especially on huge datasets like three-dimensional (3D) brain MR images. Moreover, SVM is a powerful method that is used for modeling datasets with complex feature space, but it also has huge computational cost for big datasets, especially those with strong interclass variability problems and with more than two classes such as 3D brain images; therefore, we cannot use SVM in DCS-DLTLTI. Therefore, we propose a novel approach named "DCS-SVM" to use SVM in DCS-DLTLTI to improve the accuracy of segmentation results. The proposed method is applied on well-known datasets of the Internet Brain Segmentation Repository (IBSR) and promising results are obtained.

  9. A frequency domain radar interferometric imaging (FII) technique based on high-resolution methods

    Science.gov (United States)

    Luce, H.; Yamamoto, M.; Fukao, S.; Helal, D.; Crochet, M.

    2001-01-01

    In the present work, we propose a frequency-domain interferometric imaging (FII) technique for a better knowledge of the vertical distribution of the atmospheric scatterers detected by MST radars. This is an extension of the dual frequency-domain interferometry (FDI) technique to multiple frequencies. Its objective is to reduce the ambiguity (resulting from the use of only two adjacent frequencies), inherent with the FDI technique. Different methods, commonly used in antenna array processing, are first described within the context of application to the FII technique. These methods are the Fourier-based imaging, the Capon's and the singular value decomposition method used with the MUSIC algorithm. Some preliminary simulations and tests performed on data collected with the middle and upper atmosphere (MU) radar (Shigaraki, Japan) are also presented. This work is a first step in the developments of the FII technique which seems to be very promising.

  10. Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

    OpenAIRE

    Kuang Tsan Lin; Sheng Lih Yeh

    2014-01-01

    The Rivest-Shamir-Adleman (RSA) encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matri...

  11. Method and algorithm for image processing

    Science.gov (United States)

    He, George G.; Moon, Brain D.

    2003-12-16

    The present invention is a modified Radon transform. It is similar to the traditional Radon transform for the extraction of line parameters and similar to traditional slant stack for the intensity summation of pixels away from a given pixel, for example ray paths that spans 360 degree at a given grid in the time and offset domain. However, the present invention differs from these methods in that the intensity and direction of a composite intensity for each pixel are maintained separately instead of combined after the transformation. An advantage of this approach is elimination of the work required to extract the line parameters in the transformed domain. The advantage of the modified Radon Transform method is amplified when many lines are present in the imagery or when the lines are just short segments which both occur in actual imagery.

  12. A Method for Improving the Progressive Image Coding Algorithms

    Directory of Open Access Journals (Sweden)

    Ovidiu COSMA

    2014-12-01

    Full Text Available This article presents a method for increasing the performance of the progressive coding algorithms for the subbands of images, by representing the coefficients with a code that reduces the truncation error.

  13. Development of digital image correlation method to analyse crack ...

    Indian Academy of Sciences (India)

    samples were performed to verify the performance of the digital image correlation method. ... development cannot be measured accurately. ..... Mendelson A 1983 Plasticity: Theory and application (USA: Krieger Publishing company Malabar,.

  14. Quantitative Methods for Molecular Diagnostic and Therapeutic Imaging

    OpenAIRE

    Li, Quanzheng

    2013-01-01

    This theme issue provides an overview on the basic quantitative methods, an in-depth discussion on the cutting-edge quantitative analysis approaches as well as their applications for both static and dynamic molecular diagnostic and therapeutic imaging.

  15. Discrete gradient methods for solving variational image regularisation models

    International Nuclear Information System (INIS)

    Grimm, V; McLachlan, Robert I; McLaren, David I; Quispel, G R W; Schönlieb, C-B

    2017-01-01

    Discrete gradient methods are well-known methods of geometric numerical integration, which preserve the dissipation of gradient systems. In this paper we show that this property of discrete gradient methods can be interesting in the context of variational models for image processing, that is where the processed image is computed as a minimiser of an energy functional. Numerical schemes for computing minimisers of such energies are desired to inherit the dissipative property of the gradient system associated to the energy and consequently guarantee a monotonic decrease of the energy along iterations, avoiding situations in which more computational work might lead to less optimal solutions. Under appropriate smoothness assumptions on the energy functional we prove that discrete gradient methods guarantee a monotonic decrease of the energy towards stationary states, and we promote their use in image processing by exhibiting experiments with convex and non-convex variational models for image deblurring, denoising, and inpainting. (paper)

  16. Double Minimum Variance Beamforming Method to Enhance Photoacoustic Imaging

    OpenAIRE

    Paridar, Roya; Mozaffarzadeh, Moein; Nasiriavanaki, Mohammadreza; Orooji, Mahdi

    2018-01-01

    One of the common algorithms used to reconstruct photoacoustic (PA) images is the non-adaptive Delay-and-Sum (DAS) beamformer. However, the quality of the reconstructed PA images obtained by DAS is not satisfying due to its high level of sidelobes and wide mainlobe. In contrast, adaptive beamformers, such as minimum variance (MV), result in an improved image compared to DAS. In this paper, a novel beamforming method, called Double MV (D-MV) is proposed to enhance the image quality compared to...

  17. Beam imaging sensor and method for using same

    Energy Technology Data Exchange (ETDEWEB)

    McAninch, Michael D.; Root, Jeffrey J.

    2017-01-03

    The present invention relates generally to the field of sensors for beam imaging and, in particular, to a new and useful beam imaging sensor for use in determining, for example, the power density distribution of a beam including, but not limited to, an electron beam or an ion beam. In one embodiment, the beam imaging sensor of the present invention comprises, among other items, a circumferential slit that is either circular, elliptical or polygonal in nature. In another embodiment, the beam imaging sensor of the present invention comprises, among other things, a discontinuous partially circumferential slit. Also disclosed is a method for using the various beams sensor embodiments of the present invention.

  18. Quantitative methods for the analysis of electron microscope images

    DEFF Research Database (Denmark)

    Skands, Peter Ulrik Vallø

    1996-01-01

    The topic of this thesis is an general introduction to quantitative methods for the analysis of digital microscope images. The images presented are primarily been acquired from Scanning Electron Microscopes (SEM) and interfermeter microscopes (IFM). The topic is approached though several examples...... foundation of the thesis fall in the areas of: 1) Mathematical Morphology; 2) Distance transforms and applications; and 3) Fractal geometry. Image analysis opens in general the possibility of a quantitative and statistical well founded measurement of digital microscope images. Herein lies also the conditions...

  19. Dual-force ISOMAP: a new relevance feedback method for medical image retrieval.

    Science.gov (United States)

    Shen, Hualei; Tao, Dacheng; Ma, Dianfu

    2013-01-01

    With great potential for assisting radiological image interpretation and decision making, content-based image retrieval in the medical domain has become a hot topic in recent years. Many methods to enhance the performance of content-based medical image retrieval have been proposed, among which the relevance feedback (RF) scheme is one of the most promising. Given user feedback information, RF algorithms interactively learn a user's preferences to bridge the "semantic gap" between low-level computerized visual features and high-level human semantic perception and thus improve retrieval performance. However, most existing RF algorithms perform in the original high-dimensional feature space and ignore the manifold structure of the low-level visual features of images. In this paper, we propose a new method, termed dual-force ISOMAP (DFISOMAP), for content-based medical image retrieval. Under the assumption that medical images lie on a low-dimensional manifold embedded in a high-dimensional ambient space, DFISOMAP operates in the following three stages. First, the geometric structure of positive examples in the learned low-dimensional embedding is preserved according to the isometric feature mapping (ISOMAP) criterion. To precisely model the geometric structure, a reconstruction error constraint is also added. Second, the average distance between positive and negative examples is maximized to separate them; this margin maximization acts as a force that pushes negative examples far away from positive examples. Finally, the similarity propagation technique is utilized to provide negative examples with another force that will pull them back into the negative sample set. We evaluate the proposed method on a subset of the IRMA medical image dataset with a RF-based medical image retrieval framework. Experimental results show that DFISOMAP outperforms popular approaches for content-based medical image retrieval in terms of accuracy and stability.

  20. System and method for image registration of multiple video streams

    Science.gov (United States)

    Dillavou, Marcus W.; Shum, Phillip Corey; Guthrie, Baron L.; Shenai, Mahesh B.; Deaton, Drew Steven; May, Matthew Benton

    2018-02-06

    Provided herein are methods and systems for image registration from multiple sources. A method for image registration includes rendering a common field of interest that reflects a presence of a plurality of elements, wherein at least one of the elements is a remote element located remotely from another of the elements and updating the common field of interest such that the presence of the at least one of the elements is registered relative to another of the elements.

  1. IMAGE TO POINT CLOUD METHOD OF 3D-MODELING

    Directory of Open Access Journals (Sweden)

    A. G. Chibunichev

    2012-07-01

    Full Text Available This article describes the method of constructing 3D models of objects (buildings, monuments based on digital images and a point cloud obtained by terrestrial laser scanner. The first step is the automated determination of exterior orientation parameters of digital image. We have to find the corresponding points of the image and point cloud to provide this operation. Before the corresponding points searching quasi image of point cloud is generated. After that SIFT algorithm is applied to quasi image and real image. SIFT algorithm allows to find corresponding points. Exterior orientation parameters of image are calculated from corresponding points. The second step is construction of the vector object model. Vectorization is performed by operator of PC in an interactive mode using single image. Spatial coordinates of the model are calculated automatically by cloud points. In addition, there is automatic edge detection with interactive editing available. Edge detection is performed on point cloud and on image with subsequent identification of correct edges. Experimental studies of the method have demonstrated its efficiency in case of building facade modeling.

  2. Analysis and Comparison of Objective Methods for Image Quality Assessment

    Directory of Open Access Journals (Sweden)

    P. S. Babkin

    2014-01-01

    Full Text Available The purpose of this work is research and modification of the reference objective methods for image quality assessment. The ultimate goal is to obtain a modification of formal assessments that more closely corresponds to the subjective expert estimates (MOS.In considering the formal reference objective methods for image quality assessment we used the results of other authors, which offer results and comparative analyzes of the most effective algorithms. Based on these investigations we have chosen two of the most successful algorithm for which was made a further analysis in the MATLAB 7.8 R 2009 a (PQS and MSSSIM. The publication focuses on the features of the algorithms, which have great importance in practical implementation, but are insufficiently covered in the publications by other authors.In the implemented modification of the algorithm PQS boundary detector Kirsch was replaced by the boundary detector Canny. Further experiments were carried out according to the method of the ITU-R VT.500-13 (01/2012 using monochrome images treated with different types of filters (should be emphasized that an objective assessment of image quality PQS is applicable only to monochrome images. Images were obtained with a thermal imaging surveillance system. The experimental results proved the effectiveness of this modification.In the specialized literature in the field of formal to evaluation methods pictures, this type of modification was not mentioned.The method described in the publication can be applied to various practical implementations of digital image processing.Advisability and effectiveness of using the modified method of PQS to assess the structural differences between the images are shown in the article and this will be used in solving the problems of identification and automatic control.

  3. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality - preliminary findings

    International Nuclear Information System (INIS)

    Mieville, Frederic A.; Gudinchet, Francois; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Bochud, Francois O.; Verdun, Francis R.

    2011-01-01

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI vol 4.8-7.9 mGy, DLP 37.1-178.9 mGy.cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone. (orig.)

  4. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality - preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Mieville, Frederic A. [University Hospital Center and University of Lausanne, Institute of Radiation Physics, Lausanne (Switzerland); University Hospital Center and University of Lausanne, Institute of Radiation Physics - Medical Radiology, Lausanne (Switzerland); Gudinchet, Francois; Rizzo, Elena [University Hospital Center and University of Lausanne, Department of Radiology, Lausanne (Switzerland); Ou, Phalla; Brunelle, Francis [Necker Children' s Hospital, Department of Radiology, Paris (France); Bochud, Francois O.; Verdun, Francis R. [University Hospital Center and University of Lausanne, Institute of Radiation Physics, Lausanne (Switzerland)

    2011-09-15

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI{sub vol} 4.8-7.9 mGy, DLP 37.1-178.9 mGy.cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone. (orig.)

  5. Method and apparatus to image biological interactions in plants

    Science.gov (United States)

    Weisenberger, Andrew; Bonito, Gregory M.; Reid, Chantal D.; Smith, Mark Frederick

    2015-12-22

    A method to dynamically image the actual translocation of molecular compounds of interest in a plant root, root system, and rhizosphere without disturbing the root or the soil. The technique makes use of radioactive isotopes as tracers to label molecules of interest and to image their distribution in the plant and/or soil. The method allows for the study and imaging of various biological and biochemical interactions in the rhizosphere of a plant, including, but not limited to, mycorrhizal associations in such regions.

  6. A new optimal seam method for seamless image stitching

    Science.gov (United States)

    Xue, Jiale; Chen, Shengyong; Cheng, Xu; Han, Ying; Zhao, Meng

    2017-07-01

    A novel optimal seam method which aims to stitch those images with overlapping area more seamlessly has been propos ed. Considering the traditional gradient domain optimal seam method and fusion algorithm result in bad color difference measurement and taking a long time respectively, the input images would be converted to HSV space and a new energy function is designed to seek optimal stitching path. To smooth the optimal stitching path, a simplified pixel correction and weighted average method are utilized individually. The proposed methods exhibit performance in eliminating the stitching seam compared with the traditional gradient optimal seam and high efficiency with multi-band blending algorithm.

  7. Methods for processing and analysis functional and anatomical brain images: computerized tomography, emission tomography and nuclear resonance imaging

    International Nuclear Information System (INIS)

    Mazoyer, B.M.

    1988-01-01

    The various methods for brain image processing and analysis are presented and compared. The following topics are developed: the physical basis of brain image comparison (nature and formation of signals intrinsic performance of the methods image characteristics); mathematical methods for image processing and analysis (filtering, functional parameter extraction, morphological analysis, robotics and artificial intelligence); methods for anatomical localization (neuro-anatomy atlas, proportional stereotaxic atlas, numerized atlas); methodology of cerebral image superposition (normalization, retiming); image networks [fr

  8. A distortion correction method for image intensifier and electronic portal images used in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ioannidis, G T; Geramani, K N; Zamboglou, N [Strahlenklinik, Stadtische Kliniken Offenbach, Offenbach (Germany); Uzunoglu, N [Department of Electrical and Computer Engineering, National Technical University of Athens, Athens (Greece)

    1999-12-31

    At the most of radiation departments a simulator and an `on line` verification system of the treated volume, in form of an electronic portal imaging device (EPID), are available. Networking and digital handling (saving, archiving etc.) of the image information is a necessity in the image processing procedures in order to evaluate verification and simulation recordings at the computer screen. Distortion is on the other hand prerequisite for quantitative comparison of both image modalities. Another limitation factor, in order to make quantitative assertions, is the fact that the irradiation fields in radiotherapy are usually bigger than the field of view of an image intensifier. Several segments of the irradiation field must therefore be acquired. Using pattern recognition techniques these segments can be composed into a single image. In this paper a distortion correction method will be presented. The method is based upon a well defined Grid which is embedded during the registration process on the image. The video signal from the image intensifier is acquired and processed. The grid is then recognised using image processing techniques. Ideally if all grid points are recognised, various methods can be applied in order to correct the distortion. But in practice this is not the case. Overlapping structures (bones etc.) have as a consequence that not all of the grid points can be recognised. Mathematical models from the Graph theory are applied in order to reconstruct the whole grid. The deviation of the grid points positions from the rated value is then used to calculate correction coefficients. This method (well defined grid, grid recognition, correction factors) can also be applied in verification images from the EPID or in other image modalities, and therefore a quantitative comparison in radiation treatment is possible. The distortion correction method and the application on simulator images will be presented. (authors)

  9. An improved level set method for brain MR images segmentation and bias correction.

    Science.gov (United States)

    Chen, Yunjie; Zhang, Jianwei; Macione, Jim

    2009-10-01

    Intensity inhomogeneities cause considerable difficulty in the quantitative analysis of magnetic resonance (MR) images. Thus, bias field estimation is a necessary step before quantitative analysis of MR data can be undertaken. This paper presents a variational level set approach to bias correction and segmentation for images with intensity inhomogeneities. Our method is based on an observation that intensities in a relatively small local region are separable, despite of the inseparability of the intensities in the whole image caused by the overall intensity inhomogeneity. We first define a localized K-means-type clustering objective function for image intensities in a neighborhood around each point. The cluster centers in this objective function have a multiplicative factor that estimates the bias within the neighborhood. The objective function is then integrated over the entire domain to define the data term into the level set framework. Our method is able to capture bias of quite general profiles. Moreover, it is robust to initialization, and thereby allows fully automated applications. The proposed method has been used for images of various modalities with promising results.

  10. Image Registration Using Single Cluster PHD Methods

    Science.gov (United States)

    Campbell, M.; Schlangen, I.; Delande, E.; Clark, D.

    Cadets in the Department of Physics at the United States Air Force Academy are using the technique of slitless spectroscopy to analyze the spectra from geostationary satellites during glint season. The equinox periods of the year are particularly favorable for earth-based observers to detect specular reflections off satellites (glints), which have been observed in the past using broadband photometry techniques. Three seasons of glints were observed and analyzed for multiple satellites, as measured across the visible spectrum using a diffraction grating on the Academy’s 16-inch, f/8.2 telescope. It is clear from the results that the glint maximum wavelength decreases relative to the time periods before and after the glint, and that the spectral reflectance during the glint is less like a blackbody. These results are consistent with the presumption that solar panels are the predominant source of specular reflection. The glint spectra are also quantitatively compared to different blackbody curves and the solar spectrum by means of absolute differences and standard deviations. Our initial analysis appears to indicate a potential method of determining relative power capacity.

  11. New adaptive sampling method in particle image velocimetry

    International Nuclear Information System (INIS)

    Yu, Kaikai; Xu, Jinglei; Tang, Lan; Mo, Jianwei

    2015-01-01

    This study proposes a new adaptive method to enable the number of interrogation windows and their positions in a particle image velocimetry (PIV) image interrogation algorithm to become self-adapted according to the seeding density. The proposed method can relax the constraint of uniform sampling rate and uniform window size commonly adopted in the traditional PIV algorithm. In addition, the positions of the sampling points are redistributed on the basis of the spring force generated by the sampling points. The advantages include control of the number of interrogation windows according to the local seeding density and smoother distribution of sampling points. The reliability of the adaptive sampling method is illustrated by processing synthetic and experimental images. The synthetic example attests to the advantages of the sampling method. Compared with that of the uniform interrogation technique in the experimental application, the spatial resolution is locally enhanced when using the proposed sampling method. (technical design note)

  12. Research on interpolation methods in medical image processing.

    Science.gov (United States)

    Pan, Mei-Sen; Yang, Xiao-Li; Tang, Jing-Tian

    2012-04-01

    Image interpolation is widely used for the field of medical image processing. In this paper, interpolation methods are divided into three groups: filter interpolation, ordinary interpolation and general partial volume interpolation. Some commonly-used filter methods for image interpolation are pioneered, but the interpolation effects need to be further improved. When analyzing and discussing ordinary interpolation, many asymmetrical kernel interpolation methods are proposed. Compared with symmetrical kernel ones, the former are have some advantages. After analyzing the partial volume and generalized partial volume estimation interpolations, the new concept and constraint conditions of the general partial volume interpolation are defined, and several new partial volume interpolation functions are derived. By performing the experiments of image scaling, rotation and self-registration, the interpolation methods mentioned in this paper are compared in the entropy, peak signal-to-noise ratio, cross entropy, normalized cross-correlation coefficient and running time. Among the filter interpolation methods, the median and B-spline filter interpolations have a relatively better interpolating performance. Among the ordinary interpolation methods, on the whole, the symmetrical cubic kernel interpolations demonstrate a strong advantage, especially the symmetrical cubic B-spline interpolation. However, we have to mention that they are very time-consuming and have lower time efficiency. As for the general partial volume interpolation methods, from the total error of image self-registration, the symmetrical interpolations provide certain superiority; but considering the processing efficiency, the asymmetrical interpolations are better.

  13. Advanced methods for image registration applied to JET videos

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, Teddy, E-mail: teddy.craciunescu@jet.uk [EURATOM-MEdC Association, NILPRP, Bucharest (Romania); Murari, Andrea [Consorzio RFX, Associazione EURATOM-ENEA per la Fusione, Padova (Italy); Gelfusa, Michela [Associazione EURATOM-ENEA – University of Rome “Tor Vergata”, Roma (Italy); Tiseanu, Ion; Zoita, Vasile [EURATOM-MEdC Association, NILPRP, Bucharest (Romania); Arnoux, Gilles [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom)

    2015-10-15

    Graphical abstract: - Highlights: • Development of an image registration method for JET IR and fast visible cameras. • Method based on SIFT descriptors and coherent point drift points set registration technique. • Method able to deal with extremely noisy images and very low luminosity images. • Computation time compatible with the inter-shot analysis. - Abstract: The last years have witnessed a significant increase in the use of digital cameras on JET. They are routinely applied for imaging in the IR and visible spectral regions. One of the main technical difficulties in interpreting the data of camera based diagnostics is the presence of movements of the field of view. Small movements occur due to machine shaking during normal pulses while large ones may arise during disruptions. Some cameras show a correlation of image movement with change of magnetic field strength. For deriving unaltered information from the videos and for allowing correct interpretation an image registration method, based on highly distinctive scale invariant feature transform (SIFT) descriptors and on the coherent point drift (CPD) points set registration technique, has been developed. The algorithm incorporates a complex procedure for rejecting outliers. The method has been applied for vibrations correction to videos collected by the JET wide angle infrared camera and for the correction of spurious rotations in the case of the JET fast visible camera (which is equipped with an image intensifier). The method has proved to be able to deal with the images provided by this camera frequently characterized by low contrast and a high level of blurring and noise.

  14. Method for estimating modulation transfer function from sample images.

    Science.gov (United States)

    Saiga, Rino; Takeuchi, Akihisa; Uesugi, Kentaro; Terada, Yasuko; Suzuki, Yoshio; Mizutani, Ryuta

    2018-02-01

    The modulation transfer function (MTF) represents the frequency domain response of imaging modalities. Here, we report a method for estimating the MTF from sample images. Test images were generated from a number of images, including those taken with an electron microscope and with an observation satellite. These original images were convolved with point spread functions (PSFs) including those of circular apertures. The resultant test images were subjected to a Fourier transformation. The logarithm of the squared norm of the Fourier transform was plotted against the squared distance from the origin. Linear correlations were observed in the logarithmic plots, indicating that the PSF of the test images can be approximated with a Gaussian. The MTF was then calculated from the Gaussian-approximated PSF. The obtained MTF closely coincided with the MTF predicted from the original PSF. The MTF of an x-ray microtomographic section of a fly brain was also estimated with this method. The obtained MTF showed good agreement with the MTF determined from an edge profile of an aluminum test object. We suggest that this approach is an alternative way of estimating the MTF, independently of the image type. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Research of x-ray automatic image mosaic method

    Science.gov (United States)

    Liu, Bin; Chen, Shunan; Guo, Lianpeng; Xu, Wanpeng

    2013-10-01

    Image mosaic has widely applications value in the fields of medical image analysis, and it is a technology that carries on the spatial matching to a series of image which are overlapped with each other, and finally builds a seamless and high quality image which has high resolution and big eyeshot. In this paper, the method of grayscale cutting pseudo-color enhancement was firstly used to complete the mapping transformation from gray to the pseudo-color, and to extract SIFT features from the images. And then by making use of a similar measure of NCC (normalized cross correlation - Normalized cross-correlation), the method of RANSAC (Random Sample Consensus) was used to exclude the pseudofeature points right in order to complete the exact match of feature points. Finally, seamless mosaic and color fusion were completed by using wavelet multi-decomposition. The experiment shows that the method we used can effectively improve the precision and automation of the medical image mosaic, and provide an effective technical approach for automatic medical image mosaic.

  16. [An Improved Spectral Quaternion Interpolation Method of Diffusion Tensor Imaging].

    Science.gov (United States)

    Xu, Yonghong; Gao, Shangce; Hao, Xiaofei

    2016-04-01

    Diffusion tensor imaging(DTI)is a rapid development technology in recent years of magnetic resonance imaging.The diffusion tensor interpolation is a very important procedure in DTI image processing.The traditional spectral quaternion interpolation method revises the direction of the interpolation tensor and can preserve tensors anisotropy,but the method does not revise the size of tensors.The present study puts forward an improved spectral quaternion interpolation method on the basis of traditional spectral quaternion interpolation.Firstly,we decomposed diffusion tensors with the direction of tensors being represented by quaternion.Then we revised the size and direction of the tensor respectively according to different situations.Finally,we acquired the tensor of interpolation point by calculating the weighted average.We compared the improved method with the spectral quaternion method and the Log-Euclidean method by the simulation data and the real data.The results showed that the improved method could not only keep the monotonicity of the fractional anisotropy(FA)and the determinant of tensors,but also preserve the tensor anisotropy at the same time.In conclusion,the improved method provides a kind of important interpolation method for diffusion tensor image processing.

  17. Investigation of innovative radiation imaging method and system for radiological environments

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, H. [School of Biomedical Engineering, Korea University, Seoul (Korea, Republic of); Joung, J., E-mail: jinhun.joung@nucaremed.com [School of Biomedical Engineering, Korea University, Seoul (Korea, Republic of); Nucare, Inc., Incheon (Korea, Republic of); Kim, Y. [School of Biomedical Engineering, Korea University, Seoul (Korea, Republic of); Nucare, Inc., Incheon (Korea, Republic of); Lee, K. [School of Biomedical Engineering, Korea University, Seoul (Korea, Republic of)

    2017-03-01

    demonstrated imaging of 3D space, which is the most general and fundamental task in the field of radiological environment imaging. The experiments show quite promising results. In addition, the method is able to provide quantitative information about each distribution, including isotope identification, activity concentration, and the size and shape of radiation sources. Our future studies include employing other detector modules and collimators and developing systems for other applications, such as container truck and conveyor inspections.

  18. EXPRESS METHOD OF BARCODE GENERATION FROM FACIAL IMAGES

    Directory of Open Access Journals (Sweden)

    G. A. Kukharev

    2014-03-01

    Full Text Available In the paper a method of generating of standard type linear barcodes from facial images is proposed. The method is based on use of the histogram of facial image brightness, averaging the histogram on a limited number of intervals, quantization of results in a range of decimal numbers from 0 to 9 and table conversion into the final barcode. The proposed solution is computationally low-cost and not requires the use of specialized software on image processing that allows generating of facial barcodes in mobile systems, and thus the proposed method can be interpreted as an express method. Results of tests on the Face94 and CUHK Face Sketch FERET Databases showed that the proposed method is a new solution for use in the real-world practice and ensures the stability of generated barcodes in changes of scale, pose and mirroring of a facial image, and also changes of a facial expression and shadows on faces from local lighting. The proposed method is based on generating of a standard barcode directly from the facial image, and thus contains the subjective information about a person's face.

  19. Spectral analysis of mammographic images using a multitaper method

    International Nuclear Information System (INIS)

    Wu Gang; Mainprize, James G.; Yaffe, Martin J.

    2012-01-01

    Purpose: Power spectral analysis in radiographic images is conventionally performed using a windowed overlapping averaging periodogram. This study describes an alternative approach using a multitaper technique and compares its performance with that of the standard method. This tool will be valuable in power spectrum estimation of images, whose content deviates significantly from uniform white noise. The performance of the multitaper approach will be evaluated in terms of spectral stability, variance reduction, bias, and frequency precision. The ultimate goal is the development of a useful tool for image quality assurance. Methods: A multitaper approach uses successive data windows of increasing order. This mitigates spectral leakage allowing one to calculate a reduced-variance power spectrum. The multitaper approach will be compared with the conventional power spectrum method in several typical situations, including the noise power spectra (NPS) measurements of simulated projection images of a uniform phantom, NPS measurement of real detector images of a uniform phantom for two clinical digital mammography systems, and the estimation of the anatomic noise in mammographic images (simulated images and clinical mammograms). Results: Examination of spectrum variance versus frequency resolution and bias indicates that the multitaper approach is superior to the conventional single taper methods in the prevention of spectrum leakage and variance reduction. More than four times finer frequency precision can be achieved with equivalent or less variance and bias. Conclusions: Without any shortening of the image data length, the bias is smaller and the frequency resolution is higher with the multitaper method, and the need to compromise in the choice of regions of interest size to balance between the reduction of variance and the loss of frequency resolution is largely eliminated.

  20. Reconstruction of CT images by the Bayes- back projection method

    CERN Document Server

    Haruyama, M; Takase, M; Tobita, H

    2002-01-01

    In the course of research on quantitative assay of non-destructive measurement of radioactive waste, the have developed a unique program based on the Bayesian theory for reconstruction of transmission computed tomography (TCT) image. The reconstruction of cross-section images in the CT technology usually employs the Filtered Back Projection method. The new imaging reconstruction program reported here is based on the Bayesian Back Projection method, and it has a function of iterative improvement images by every step of measurement. Namely, this method has the capability of prompt display of a cross-section image corresponding to each angled projection data from every measurement. Hence, it is possible to observe an improved cross-section view by reflecting each projection data in almost real time. From the basic theory of Baysian Back Projection method, it can be not only applied to CT types of 1st, 2nd, and 3rd generation. This reported deals with a reconstruction program of cross-section images in the CT of ...

  1. Multi-crack imaging using nonclassical nonlinear acoustic method

    International Nuclear Information System (INIS)

    Zhang Lue; Zhang Ying; Liu Xiao-Zhou; Gong Xiu-Fen

    2014-01-01

    Solid materials with cracks exhibit the nonclassical nonlinear acoustical behavior. The micro-defects in solid materials can be detected by nonlinear elastic wave spectroscopy (NEWS) method with a time-reversal (TR) mirror. While defects lie in viscoelastic solid material with different distances from one another, the nonlinear and hysteretic stress—strain relation is established with Preisach—Mayergoyz (PM) model in crack zone. Pulse inversion (PI) and TR methods are used in numerical simulation and defect locations can be determined from images obtained by the maximum value. Since false-positive defects might appear and degrade the imaging when the defects are located quite closely, the maximum value imaging with a time window is introduced to analyze how defects affect each other and how the fake one occurs. Furthermore, NEWS-TR-NEWS method is put forward to improve NEWS-TR scheme, with another forward propagation (NEWS) added to the existing phases (NEWS and TR). In the added phase, scanner locations are determined by locations of all defects imaged in previous phases, so that whether an imaged defect is real can be deduced. NEWS-TR-NEWS method is proved to be effective to distinguish real defects from the false-positive ones. Moreover, it is also helpful to detect the crack that is weaker than others during imaging procedure. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  2. Multi-crack imaging using nonclassical nonlinear acoustic method

    Science.gov (United States)

    Zhang, Lue; Zhang, Ying; Liu, Xiao-Zhou; Gong, Xiu-Fen

    2014-10-01

    Solid materials with cracks exhibit the nonclassical nonlinear acoustical behavior. The micro-defects in solid materials can be detected by nonlinear elastic wave spectroscopy (NEWS) method with a time-reversal (TR) mirror. While defects lie in viscoelastic solid material with different distances from one another, the nonlinear and hysteretic stress—strain relation is established with Preisach—Mayergoyz (PM) model in crack zone. Pulse inversion (PI) and TR methods are used in numerical simulation and defect locations can be determined from images obtained by the maximum value. Since false-positive defects might appear and degrade the imaging when the defects are located quite closely, the maximum value imaging with a time window is introduced to analyze how defects affect each other and how the fake one occurs. Furthermore, NEWS-TR-NEWS method is put forward to improve NEWS-TR scheme, with another forward propagation (NEWS) added to the existing phases (NEWS and TR). In the added phase, scanner locations are determined by locations of all defects imaged in previous phases, so that whether an imaged defect is real can be deduced. NEWS-TR-NEWS method is proved to be effective to distinguish real defects from the false-positive ones. Moreover, it is also helpful to detect the crack that is weaker than others during imaging procedure.

  3. A Quick and Affine Invariance Matching Method for Oblique Images

    Directory of Open Access Journals (Sweden)

    XIAO Xiongwu

    2015-04-01

    Full Text Available This paper proposed a quick, affine invariance matching method for oblique images. It calculated the initial affine matrix by making full use of the two estimated camera axis orientation parameters of an oblique image, then recovered the oblique image to a rectified image by doing the inverse affine transform, and left over by the SIFT method. We used the nearest neighbor distance ratio(NNDR, normalized cross correlation(NCC measure constraints and consistency check to get the coarse matches, then used RANSAC method to calculate the fundamental matrix and the homography matrix. And we got the matches that they were interior points when calculating the homography matrix, then calculated the average value of the matches' principal direction differences. During the matching process, we got the initial matching features by the nearest neighbor(NN matching strategy, then used the epipolar constrains, homography constrains, NCC measure constrains and consistency check of the initial matches' principal direction differences with the calculated average value of the interior matches' principal direction differences to eliminate false matches. Experiments conducted on three pairs of typical oblique images demonstrate that our method takes about the same time as SIFT to match a pair of oblique images with a plenty of corresponding points distributed evenly and an extremely low mismatching rate.

  4. A Study on the Improvement of Digital Periapical Images using Image Interpolation Methods

    International Nuclear Information System (INIS)

    Song, Nam Kyu; Koh, Kwang Joon

    1998-01-01

    Image resampling is of particular interest in digital radiology. When resampling an image to a new set of coordinate, there appears blocking artifacts and image changes. To enhance image quality, interpolation algorithms have been used. Resampling is used to increase the number of points in an image to improve its appearance for display. The process of interpolation is fitting a continuous function to the discrete points in the digital image. The purpose of this study was to determine the effects of the seven interpolation functions when image resampling in digital periapical images. The images were obtained by Digora, CDR and scanning of Ektaspeed plus periapical radiograms on the dry skull and human subject. The subjects were exposed to intraoral X-ray machine at 60 kVp and 70 kVp with exposure time varying between 0.01 and 0.50 second. To determine which interpolation method would provide the better image, seven functions were compared ; (1) nearest neighbor (2) linear (3) non-linear (4) facet model (5) cubic convolution (6) cubic spline (7) gray segment expansion. And resampled images were compared in terms of SNR (Signal to Noise Ratio) and MTF (Modulation Transfer Function) coefficient value. The obtained results were as follows ; 1. The highest SNR value (75.96 dB) was obtained with cubic convolution method and the lowest SNR value (72.44 dB) was obtained with facet model method among seven interpolation methods. 2. There were significant differences of SNR values among CDR, Digora and film scan (P 0.05). 4. There were significant differences of MTF coefficient values between linear interpolation method and the other six interpolation methods (P<0.05). 5. The speed of computation time was the fastest with nearest neighbor method and the slowest with non-linear method. 6. The better image was obtained with cubic convolution, cubic spline and gray segment method in ROC analysis. 7. The better sharpness of edge was obtained with gray segment expansion method

  5. A new method of the light irradiation image by the computed radiography (imaging plate) system

    International Nuclear Information System (INIS)

    Aiba, Susumu; Nishi, Katsuki.

    1997-01-01

    There are two method for the purpose of diagnosing medically by using gamma-ray light irradiation image. One is to use of the scintillation camera for gamma-ray, the other is to use of the photostimulable luminescence point by the secondary excitation of the image plate (IP) system for X-ray. The standpoint of the spatial resolution at the total medical image, using gamma-ray, the first can get the image on a short time, but the first is a poor image quality, and the second is good image quality, but the second can get the image on a long time, because of insensitive to gamma-ray. We report on the improvement for IP's week point by our proposal method, and by our clinical and quantitative analysis data, to use the highly efficient IP (ST-III). We make the improvement on the imaging time (from 30 minutes to 20 minutes), and the inprocessing time (from 33-50 minutes to 27 minutes) for a former method on an organism. We strongly believe that our convenience improvement method, and our clinical quantitative analysis data can contribute to the wide application as well as the quality up for the clinical diagnosis to use gamma-ray. (author)

  6. Dynamic PET Image reconstruction for parametric imaging using the HYPR kernel method

    Science.gov (United States)

    Spencer, Benjamin; Qi, Jinyi; Badawi, Ramsey D.; Wang, Guobao

    2017-03-01

    Dynamic PET image reconstruction is a challenging problem because of the ill-conditioned nature of PET and the lowcounting statistics resulted from short time-frames in dynamic imaging. The kernel method for image reconstruction has been developed to improve image reconstruction of low-count PET data by incorporating prior information derived from high-count composite data. In contrast to most of the existing regularization-based methods, the kernel method embeds image prior information in the forward projection model and does not require an explicit regularization term in the reconstruction formula. Inspired by the existing highly constrained back-projection (HYPR) algorithm for dynamic PET image denoising, we propose in this work a new type of kernel that is simpler to implement and further improves the kernel-based dynamic PET image reconstruction. Our evaluation study using a physical phantom scan with synthetic FDG tracer kinetics has demonstrated that the new HYPR kernel-based reconstruction can achieve a better region-of-interest (ROI) bias versus standard deviation trade-off for dynamic PET parametric imaging than the post-reconstruction HYPR denoising method and the previously used nonlocal-means kernel.

  7. Neuroimaging of language processes: fMRI of silent and overt lexical processing and the promise of multiple process imaging in single brain studies

    International Nuclear Information System (INIS)

    Borowsky, R.; Owen, W.J.; Wile, T.L.; Friesen, C.K.; Martin, J.L.; Sarty, G.E.

    2005-01-01

    To implement and evaluate a multiple-process functional magnetic resonance imaging (fMRI) paradigm designed to effectively and efficiently activate several language-related regions for use with neurosurgical patients. Both overt and covert response conditions were examined. The fMRI experiments compared the traditional silent word-generation condition versus an overt one as they engage frontal language regions (Experiment 1) and silent versus overt semantic association conditions as they engage multiple language processing regions (Experiment 2). In Experiment 1 the overt condition yielded greater magnitude of activation, but not volume of activation, in the left inferior frontal and insular cortices than did the silent condition for most, but not all, participants. Experiment 2 demonstrated that the activation of multiple established language processing regions (ie, orthographic, phonological and semantic) can be achieved in a significant number of participants, particularly under overt semantic association conditions and that such activation varies in predictable ways. The traditional silent response condition cannot be considered as equivalent to the overt response condition during word generation or semantic association. The multiple-process imaging method introduced here was sensitive to processing robust orthographic, phonological, and semantic regions, particularly under the overt response condition. (author)

  8. Denoising imaging polarimetry by adapted BM3D method.

    Science.gov (United States)

    Tibbs, Alexander B; Daly, Ilse M; Roberts, Nicholas W; Bull, David R

    2018-04-01

    In addition to the visual information contained in intensity and color, imaging polarimetry allows visual information to be extracted from the polarization of light. However, a major challenge of imaging polarimetry is image degradation due to noise. This paper investigates the mitigation of noise through denoising algorithms and compares existing denoising algorithms with a new method, based on BM3D (Block Matching 3D). This algorithm, Polarization-BM3D (PBM3D), gives visual quality superior to the state of the art across all images and noise standard deviations tested. We show that denoising polarization images using PBM3D allows the degree of polarization to be more accurately calculated by comparing it with spectral polarimetry measurements.

  9. Metal artifact reduction method using metal streaks image subtraction

    International Nuclear Information System (INIS)

    Pua, Rizza D.; Cho, Seung Ryong

    2014-01-01

    Many studies have been dedicated for metal artifact reduction (MAR); however, the methods are successful to varying degrees depending on situations. Sinogram in-painting, filtering, iterative method are some of the major categories of MAR. Each has its own merits and weaknesses. A combination of these methods or hybrid methods have also been developed to make use of the different benefits of two techniques and minimize the unfavorable results. Our method focuses on the in-paitning approach and a hybrid MAR described by Xia et al. Although in-painting scheme is an effective technique in reducing the primary metal artifacts, a major drawback is the reintroduction of new artifacts that can be caused by an inaccurate interpolation process. Furthermore, combining the segmented metal image to the corrected nonmetal image in the final step of a conventional inpainting approach causes an issue of incorrect metal pixel values. Our proposed method begins with a sinogram in-painting approach and ends with an image-based metal artifact reduction scheme. This work provides a simple, yet effective solution for reducing metal artifacts and acquiring the original metal pixel information. The proposed method demonstrated its effectiveness in a simulation setting. The proposed method showed image quality that is comparable to the standard MAR; however, quantitatively more accurate than the standard MAR

  10. Combination of acoustical radiosity and the image source method

    DEFF Research Database (Denmark)

    Koutsouris, Georgios I; Brunskog, Jonas; Jeong, Cheol-Ho

    2013-01-01

    A combined model for room acoustic predictions is developed, aiming to treat both diffuse and specular reflections in a unified way. Two established methods are incorporated: acoustical radiosity, accounting for the diffuse part, and the image source method, accounting for the specular part...

  11. Multi-spectral lifetime imaging: methods and applications

    NARCIS (Netherlands)

    Fereidouni, F.

    2013-01-01

    The aim of this PhD project is to further develop multispectral life time imaging hardware and analyses methods. The hardware system, Lambda-Tau, generates a considerable amount of data at high speed. To fully exploit the power of this new hardware, fast and reliable data analyses methods are

  12. An effective method on pornographic images realtime recognition

    Science.gov (United States)

    Wang, Baosong; Lv, Xueqiang; Wang, Tao; Wang, Chengrui

    2013-03-01

    In this paper, skin detection, texture filtering and face detection are used to extract feature on an image library, training them with the decision tree arithmetic to create some rules as a decision tree classifier to distinguish an unknown image. Experiment based on more than twenty thousand images, the precision rate can get 76.21% when testing on 13025 pornographic images and elapsed time is less than 0.2s. This experiment shows it has a good popularity. Among the steps mentioned above, proposing a new skin detection model which called irregular polygon region skin detection model based on YCbCr color space. This skin detection model can lower the false detection rate on skin detection. A new method called sequence region labeling on binary connected area can calculate features on connected area, it is faster and needs less memory than other recursive methods.

  13. A Single Image Dehazing Method Using Average Saturation Prior

    Directory of Open Access Journals (Sweden)

    Zhenfei Gu

    2017-01-01

    Full Text Available Outdoor images captured in bad weather are prone to yield poor visibility, which is a fatal problem for most computer vision applications. The majority of existing dehazing methods rely on an atmospheric scattering model and therefore share a common limitation; that is, the model is only valid when the atmosphere is homogeneous. In this paper, we propose an improved atmospheric scattering model to overcome this inherent limitation. By adopting the proposed model, a corresponding dehazing method is also presented. In this method, we first create a haze density distribution map of a hazy image, which enables us to segment the hazy image into scenes according to the haze density similarity. Then, in order to improve the atmospheric light estimation accuracy, we define an effective weight assignment function to locate a candidate scene based on the scene segmentation results and therefore avoid most potential errors. Next, we propose a simple but powerful prior named the average saturation prior (ASP, which is a statistic of extensive high-definition outdoor images. Using this prior combined with the improved atmospheric scattering model, we can directly estimate the scene atmospheric scattering coefficient and restore the scene albedo. The experimental results verify that our model is physically valid, and the proposed method outperforms several state-of-the-art single image dehazing methods in terms of both robustness and effectiveness.

  14. Method of Poisson's ratio imaging within a material part

    Science.gov (United States)

    Roth, Don J. (Inventor)

    1996-01-01

    The present invention is directed to a method of displaying the Poisson's ratio image of a material part. In the present invention longitudinal data is produced using a longitudinal wave transducer and shear wave data is produced using a shear wave transducer. The respective data is then used to calculate the Poisson's ratio for the entire material part. The Poisson's ratio approximations are then used to displayed the image.

  15. Interpretation of the method of images in estimating superconducting levitation

    International Nuclear Information System (INIS)

    Perez-Diaz, Jose Luis; Garcia-Prada, Juan Carlos

    2007-01-01

    Among different papers devoted to superconducting levitation of a permanent magnet over a superconductor using the method of images, there is a discrepancy of a factor of two when estimating the lift force. This is not a minor matter but an interesting fundamental question that contributes to understanding the physical phenomena of 'imaging' on a superconductor surface. We solve it, make clear the physical behavior underlying it, and suggest the reinterpretation of some previous experiments

  16. A developed unsharp masking method for images contrast enhancement

    International Nuclear Information System (INIS)

    Zaafouri, A.; Sayadi, M.; Fnaiech, F.

    2011-01-01

    In this paper, we propose a developed unsharp masking process for contrast image enhancement. The main idea here is to enhance the dark and bright area in the same way which matches the response of human visual system well. Then in order to reduce the noise effect, a mean weighted high pass filter is used for edge extraction. The proposed method gives satisfactory results for wide range of low contrast images compared with others known approaches.

  17. Bin mode estimation methods for Compton camera imaging

    International Nuclear Information System (INIS)

    Ikeda, S.; Odaka, H.; Uemura, M.; Takahashi, T.; Watanabe, S.; Takeda, S.

    2014-01-01

    We study the image reconstruction problem of a Compton camera which consists of semiconductor detectors. The image reconstruction is formulated as a statistical estimation problem. We employ a bin-mode estimation (BME) and extend an existing framework to a Compton camera with multiple scatterers and absorbers. Two estimation algorithms are proposed: an accelerated EM algorithm for the maximum likelihood estimation (MLE) and a modified EM algorithm for the maximum a posteriori (MAP) estimation. Numerical simulations demonstrate the potential of the proposed methods

  18. Cross-relaxation imaging:methods, challenges and applications

    International Nuclear Information System (INIS)

    Stikov, Nikola

    2010-01-01

    An overview of quantitative magnetization transfer (qMT) is given, with focus on cross relaxation imaging (CRI) as a fast method for quantifying the proportion of protons bound to complex macromolecules in tissue. The procedure for generating CRI maps is outlined, showing examples in the human brain and knee, and discussing the caveats and challenges in generating precise and accurate CRI maps. Finally, several applications of CRI for imaging tissue microstructure are presented.(Author)

  19. Classification Method in Integrated Information Network Using Vector Image Comparison

    Directory of Open Access Journals (Sweden)

    Zhou Yuan

    2014-05-01

    Full Text Available Wireless Integrated Information Network (WMN consists of integrated information that can get data from its surrounding, such as image, voice. To transmit information, large resource is required which decreases the service time of the network. In this paper we present a Classification Approach based on Vector Image Comparison (VIC for WMN that improve the service time of the network. The available methods for sub-region selection and conversion are also proposed.

  20. An Efficient Evolutionary Based Method For Image Segmentation

    OpenAIRE

    Aslanzadeh, Roohollah; Qazanfari, Kazem; Rahmati, Mohammad

    2017-01-01

    The goal of this paper is to present a new efficient image segmentation method based on evolutionary computation which is a model inspired from human behavior. Based on this model, a four layer process for image segmentation is proposed using the split/merge approach. In the first layer, an image is split into numerous regions using the watershed algorithm. In the second layer, a co-evolutionary process is applied to form centers of finals segments by merging similar primary regions. In the t...

  1. Breast EIT using a new projected image reconstruction method with multi-frequency measurements.

    Science.gov (United States)

    Lee, Eunjung; Ts, Munkh-Erdene; Seo, Jin Keun; Woo, Eung Je

    2012-05-01

    We propose a new method to produce admittivity images of the breast for the diagnosis of breast cancer using electrical impedance tomography(EIT). Considering the anatomical structure of the breast, we designed an electrode configuration where current-injection and voltage-sensing electrodes are separated in such a way that internal current pathways are approximately along the tangential direction of an array of voltage-sensing electrodes. Unlike conventional EIT imaging methods where the number of injected currents is maximized to increase the total amount of measured data, current is injected only twice between two pairs of current-injection electrodes attached along the circumferential side of the breast. For each current injection, the induced voltages are measured from the front surface of the breast using as many voltage-sensing electrodes as possible. Although this electrode configurational lows us to measure induced voltages only on the front surface of the breast,they are more sensitive to an anomaly inside the breast since such an injected current tends to produce a more uniform internal current density distribution. Furthermore, the sensitivity of a measured boundary voltage between two equipotential lines on the front surface of the breast is improved since those equipotential lines are perpendicular to the primary direction of internal current streamlines. One should note that this novel data collection method is different from those of other frontal plane techniques such as the x-ray projection and T-scan imaging methods because we do not get any data on the plane that is perpendicular to the current flow. To reconstruct admittivity images using two measured voltage data sets, a new projected image reconstruction algorithm is developed. Numerical simulations demonstrate the frequency-difference EIT imaging of the breast. The results show that the new method is promising to accurately detect and localize small anomalies inside the breast.

  2. Breast EIT using a new projected image reconstruction method with multi-frequency measurements

    International Nuclear Information System (INIS)

    Lee, Eunjung; Ts, Munkh-Erdene; Seo, Jin Keun; Woo, Eung Je

    2012-01-01

    We propose a new method to produce admittivity images of the breast for the diagnosis of breast cancer using electrical impedance tomography (EIT). Considering the anatomical structure of the breast, we designed an electrode configuration where current-injection and voltage-sensing electrodes are separated in such a way that internal current pathways are approximately along the tangential direction of an array of voltage-sensing electrodes. Unlike conventional EIT imaging methods where the number of injected currents is maximized to increase the total amount of measured data, current is injected only twice between two pairs of current-injection electrodes attached along the circumferential side of the breast. For each current injection, the induced voltages are measured from the front surface of the breast using as many voltage-sensing electrodes as possible. Although this electrode configuration allows us to measure induced voltages only on the front surface of the breast, they are more sensitive to an anomaly inside the breast since such an injected current tends to produce a more uniform internal current density distribution. Furthermore, the sensitivity of a measured boundary voltage between two equipotential lines on the front surface of the breast is improved since those equipotential lines are perpendicular to the primary direction of internal current streamlines. One should note that this novel data collection method is different from those of other frontal plane techniques such as the x-ray projection and T-scan imaging methods because we do not get any data on the plane that is perpendicular to the current flow. To reconstruct admittivity images using two measured voltage data sets, a new projected image reconstruction algorithm is developed. Numerical simulations demonstrate the frequency-difference EIT imaging of the breast. The results show that the new method is promising to accurately detect and localize small anomalies inside the breast. (paper)

  3. Sharpening methods for images captured through Bayer matrix

    Science.gov (United States)

    Kalevo, Ossi; Rantanen, Henry, Jr.

    2003-05-01

    Image resolution and sharpness are essential criteria for a human observer when estimating the image quality. Typically cheap small-sized, low-resolution CMOS-camera sensors do not provide sharp enough images, at least when comparing to high-end digital cameras. Sharpening function can be used to increase the subjective sharpness seen by the observer. In this paper, few methods to apply sharpening for images captured by CMOS imaging sensors through color filter array (CFA) are compared. The sharpening easily adds also the visibility of noise, pixel-cross talk and interpolation artifacts. Necessary arrangements to avoid the amplification of these unwanted phenomenon are discussed. By applying the sharpening only to the green component the processing power requirements can be clearly reduced. By adjusting the red and blue component sharpness, according to the green component sharpening, creation of false colors are reduced highly. Direction search sharpening method can be used to reduce the amplification of the artifacts caused by the CFA interpolation (CFAI). The comparison of the presented methods is based mainly on subjective image quality. Also the processing power and memory requirements are considered.

  4. Hyperspectral image compressing using wavelet-based method

    Science.gov (United States)

    Yu, Hui; Zhang, Zhi-jie; Lei, Bo; Wang, Chen-sheng

    2017-10-01

    Hyperspectral imaging sensors can acquire images in hundreds of continuous narrow spectral bands. Therefore each object presented in the image can be identified from their spectral response. However, such kind of imaging brings a huge amount of data, which requires transmission, processing, and storage resources for both airborne and space borne imaging. Due to the high volume of hyperspectral image data, the exploration of compression strategies has received a lot of attention in recent years. Compression of hyperspectral data cubes is an effective solution for these problems. Lossless compression of the hyperspectral data usually results in low compression ratio, which may not meet the available resources; on the other hand, lossy compression may give the desired ratio, but with a significant degradation effect on object identification performance of the hyperspectral data. Moreover, most hyperspectral data compression techniques exploits the similarities in spectral dimensions; which requires bands reordering or regrouping, to make use of the spectral redundancy. In this paper, we explored the spectral cross correlation between different bands, and proposed an adaptive band selection method to obtain the spectral bands which contain most of the information of the acquired hyperspectral data cube. The proposed method mainly consist three steps: First, the algorithm decomposes the original hyperspectral imagery into a series of subspaces based on the hyper correlation matrix of the hyperspectral images between different bands. And then the Wavelet-based algorithm is applied to the each subspaces. At last the PCA method is applied to the wavelet coefficients to produce the chosen number of components. The performance of the proposed method was tested by using ISODATA classification method.

  5. On the pinned field image binarization for signature generation in image ownership verification method

    Directory of Open Access Journals (Sweden)

    Chang Hsuan

    2011-01-01

    Full Text Available Abstract The issue of pinned field image binarization for signature generation in the ownership verification of the protected image is investigated. The pinned field explores the texture information of the protected image and can be employed to enhance the watermark robustness. In the proposed method, four optimization schemes are utilized to determine the threshold values for transforming the pinned field into a binary feature image, which is then utilized to generate an effective signature image. Experimental results show that the utilization of optimization schemes can significantly improve the signature robustness from the previous method (Lee and Chang, Opt. Eng. 49 (9, 097005, 2010. While considering both the watermark retrieval rate and the computation speed, the genetic algorithm is strongly recommended. In addition, compared with Chang and Lin's scheme (J. Syst. Softw. 81 (7, 1118-1129, 2008, the proposed scheme also has better performance.

  6. Fast method of constructing image correlations to build a free network based on image multivocabulary trees

    Science.gov (United States)

    Zhan, Zongqian; Wang, Xin; Wei, Minglu

    2015-05-01

    In image-based three-dimensional (3-D) reconstruction, one topic of growing importance is how to quickly obtain a 3-D model from a large number of images. The retrieval of the correct and relevant images for the model poses a considerable technological challenge. The "image vocabulary tree" has been proposed as a method to search for similar images. However, a significant drawback of this approach is identified in its low time efficiency and barely satisfactory classification result. The method proposed is inspired by, and improves upon, some recent methods. Specifically, vocabulary quality is considered and multivocabulary trees are designed to improve the classification result. A marked improvement was, indeed, observed in our evaluation of the proposed method. To improve time efficiency, graphics processing unit (GPU) computer unified device architecture parallel computation is applied in the multivocabulary trees. The results of the experiments showed that the GPU was three to four times more efficient than the enumeration matching and CPU methods when the number of images is large. This paper presents a reliable reference method for the rapid construction of a free network to be used for the computing of 3-D information.

  7. Splitting methods in communication, imaging, science, and engineering

    CERN Document Server

    Osher, Stanley; Yin, Wotao

    2016-01-01

    This book is about computational methods based on operator splitting. It consists of twenty-three chapters written by recognized splitting method contributors and practitioners, and covers a vast spectrum of topics and application areas, including computational mechanics, computational physics, image processing, wireless communication, nonlinear optics, and finance. Therefore, the book presents very versatile aspects of splitting methods and their applications, motivating the cross-fertilization of ideas. .

  8. Domain decomposition methods for solving an image problem

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, W.K.; Tong, C.S. [Hong Kong Baptist College (Hong Kong)

    1994-12-31

    The domain decomposition method is a technique to break up a problem so that ensuing sub-problems can be solved on a parallel computer. In order to improve the convergence rate of the capacitance systems, pre-conditioned conjugate gradient methods are commonly used. In the last decade, most of the efficient preconditioners are based on elliptic partial differential equations which are particularly useful for solving elliptic partial differential equations. In this paper, the authors apply the so called covering preconditioner, which is based on the information of the operator under investigation. Therefore, it is good for various kinds of applications, specifically, they shall apply the preconditioned domain decomposition method for solving an image restoration problem. The image restoration problem is to extract an original image which has been degraded by a known convolution process and additive Gaussian noise.

  9. A novel optical gating method for laser gated imaging

    Science.gov (United States)

    Ginat, Ran; Schneider, Ron; Zohar, Eyal; Nesher, Ofer

    2013-06-01

    For the past 15 years, Elbit Systems is developing time-resolved active laser-gated imaging (LGI) systems for various applications. Traditional LGI systems are based on high sensitive gated sensors, synchronized to pulsed laser sources. Elbit propriety multi-pulse per frame method, which is being implemented in LGI systems, improves significantly the imaging quality. A significant characteristic of the LGI is its ability to penetrate a disturbing media, such as rain, haze and some fog types. Current LGI systems are based on image intensifier (II) sensors, limiting the system in spectral response, image quality, reliability and cost. A novel propriety optical gating module was developed in Elbit, untying the dependency of LGI system on II. The optical gating module is not bounded to the radiance wavelength and positioned between the system optics and the sensor. This optical gating method supports the use of conventional solid state sensors. By selecting the appropriate solid state sensor, the new LGI systems can operate at any desired wavelength. In this paper we present the new gating method characteristics, performance and its advantages over the II gating method. The use of the gated imaging systems is described in a variety of applications, including results from latest field experiments.

  10. Feature extraction from mammographic images using fast marching methods

    International Nuclear Information System (INIS)

    Bottigli, U.; Golosio, B.

    2002-01-01

    Features extraction from medical images represents a fundamental step for shape recognition and diagnostic support. The present work faces the problem of the detection of large features, such as massive lesions and organ contours, from mammographic images. The regions of interest are often characterized by an average grayness intensity that is different from the surrounding. In most cases, however, the desired features cannot be extracted by simple gray level thresholding, because of image noise and non-uniform density of the surrounding tissue. In this work, edge detection is achieved through the fast marching method (Level Set Methods and Fast Marching Methods, Cambridge University Press, Cambridge, 1999), which is based on the theory of interface evolution. Starting from a seed point in the shape of interest, a front is generated which evolves according to an appropriate speed function. Such function is expressed in terms of geometric properties of the evolving interface and of image properties, and should become zero when the front reaches the desired boundary. Some examples of application of such method to mammographic images from the CALMA database (Nucl. Instr. and Meth. A 460 (2001) 107) are presented here and discussed

  11. SAR Data Fusion Imaging Method Oriented to Target Feature Extraction

    Directory of Open Access Journals (Sweden)

    Yang Wei

    2015-02-01

    Full Text Available To deal with the difficulty for target outlines extracting precisely due to neglect of target scattering characteristic variation during the processing of high-resolution space-borne SAR data, a novel fusion imaging method is proposed oriented to target feature extraction. Firstly, several important aspects that affect target feature extraction and SAR image quality are analyzed, including curved orbit, stop-and-go approximation, atmospheric delay, and high-order residual phase error. Furthermore, the corresponding compensation methods are addressed as well. Based on the analysis, the mathematical model of SAR echo combined with target space-time spectrum is established for explaining the space-time-frequency change rule of target scattering characteristic. Moreover, a fusion imaging strategy and method under high-resolution and ultra-large observation angle range conditions are put forward to improve SAR quality by fusion processing in range-doppler and image domain. Finally, simulations based on typical military targets are used to verify the effectiveness of the fusion imaging method.

  12. Images Encryption Method using Steganographic LSB Method, AES and RSA algorithm

    Science.gov (United States)

    Moumen, Abdelkader; Sissaoui, Hocine

    2017-03-01

    Vulnerability of communication of digital images is an extremely important issue nowadays, particularly when the images are communicated through insecure channels. To improve communication security, many cryptosystems have been presented in the image encryption literature. This paper proposes a novel image encryption technique based on an algorithm that is faster than current methods. The proposed algorithm eliminates the step in which the secrete key is shared during the encryption process. It is formulated based on the symmetric encryption, asymmetric encryption and steganography theories. The image is encrypted using a symmetric algorithm, then, the secret key is encrypted by means of an asymmetrical algorithm and it is hidden in the ciphered image using a least significant bits steganographic scheme. The analysis results show that while enjoying the faster computation, our method performs close to optimal in terms of accuracy.

  13. Ortho Image and DTM Generation with Intelligent Methods

    Science.gov (United States)

    Bagheri, H.; Sadeghian, S.

    2013-10-01

    Nowadays the artificial intelligent algorithms has considered in GIS and remote sensing. Genetic algorithm and artificial neural network are two intelligent methods that are used for optimizing of image processing programs such as edge extraction and etc. these algorithms are very useful for solving of complex program. In this paper, the ability and application of genetic algorithm and artificial neural network in geospatial production process like geometric modelling of satellite images for ortho photo generation and height interpolation in raster Digital Terrain Model production process is discussed. In first, the geometric potential of Ikonos-2 and Worldview-2 with rational functions, 2D & 3D polynomials were tested. Also comprehensive experiments have been carried out to evaluate the viability of the genetic algorithm for optimization of rational function, 2D & 3D polynomials. Considering the quality of Ground Control Points, the accuracy (RMSE) with genetic algorithm and 3D polynomials method for Ikonos-2 Geo image was 0.508 pixel sizes and the accuracy (RMSE) with GA algorithm and rational function method for Worldview-2 image was 0.930 pixel sizes. For more another optimization artificial intelligent methods, neural networks were used. With the use of perceptron network in Worldview-2 image, a result of 0.84 pixel sizes with 4 neurons in middle layer was gained. The final conclusion was that with artificial intelligent algorithms it is possible to optimize the existing models and have better results than usual ones. Finally the artificial intelligence methods, like genetic algorithms as well as neural networks, were examined on sample data for optimizing interpolation and for generating Digital Terrain Models. The results then were compared with existing conventional methods and it appeared that these methods have a high capacity in heights interpolation and that using these networks for interpolating and optimizing the weighting methods based on inverse

  14. A systematic desaturation method for images from the Atmospheric Imaging Assembly in the Solar Dynamics Observatory.

    Science.gov (United States)

    Torre, Gabriele; Schwartz, Richard; Piana, Michele; Massone, Anna Maria; Benvenuto, Federico

    2016-05-01

    The fine spatial resolution of the SDO AIA CCD's is often destroyed by the charge in saturated pixels overflowing into a swath of neighboring cells during fast rising solar flares. Automated exposure control can only mitigate this issue to a degree and it has other deleterious effects. Our method addresses the desaturation problem for AIA images as an image reconstruction problem in which the information content of the diffraction fringes, generated by the interaction between the incoming radiation and the hardware of the spacecraft, is exploited to recover the true image intensities within the primary saturated core of the image. This methodology takes advantage of some well defined techniques like cross-correlation and the Expectation Maximization method to invert the direct relation between the diffraction fringes intensities and the true flux intensities. During this talk a complete overview on the structure of the method will be provided, besides some reliability tests obtained by its application against synthetic and real data.

  15. Deep kernel learning method for SAR image target recognition

    Science.gov (United States)

    Chen, Xiuyuan; Peng, Xiyuan; Duan, Ran; Li, Junbao

    2017-10-01

    With the development of deep learning, research on image target recognition has made great progress in recent years. Remote sensing detection urgently requires target recognition for military, geographic, and other scientific research. This paper aims to solve the synthetic aperture radar image target recognition problem by combining deep and kernel learning. The model, which has a multilayer multiple kernel structure, is optimized layer by layer with the parameters of Support Vector Machine and a gradient descent algorithm. This new deep kernel learning method improves accuracy and achieves competitive recognition results compared with other learning methods.

  16. Studying depression using imaging and machine learning methods

    Directory of Open Access Journals (Sweden)

    Meenal J. Patel

    2016-01-01

    Full Text Available Depression is a complex clinical entity that can pose challenges for clinicians regarding both accurate diagnosis and effective timely treatment. These challenges have prompted the development of multiple machine learning methods to help improve the management of this disease. These methods utilize anatomical and physiological data acquired from neuroimaging to create models that can identify depressed patients vs. non-depressed patients and predict treatment outcomes. This article (1 presents a background on depression, imaging, and machine learning methodologies; (2 reviews methodologies of past studies that have used imaging and machine learning to study depression; and (3 suggests directions for future depression-related studies.

  17. Studying depression using imaging and machine learning methods.

    Science.gov (United States)

    Patel, Meenal J; Khalaf, Alexander; Aizenstein, Howard J

    2016-01-01

    Depression is a complex clinical entity that can pose challenges for clinicians regarding both accurate diagnosis and effective timely treatment. These challenges have prompted the development of multiple machine learning methods to help improve the management of this disease. These methods utilize anatomical and physiological data acquired from neuroimaging to create models that can identify depressed patients vs. non-depressed patients and predict treatment outcomes. This article (1) presents a background on depression, imaging, and machine learning methodologies; (2) reviews methodologies of past studies that have used imaging and machine learning to study depression; and (3) suggests directions for future depression-related studies.

  18. Quantitative Nuclear Medicine Imaging: Concepts, Requirements and Methods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-01-15

    The absolute quantification of radionuclide distribution has been a goal since the early days of nuclear medicine. Nevertheless, the apparent complexity and sometimes limited accuracy of these methods have prevented them from being widely used in important applications such as targeted radionuclide therapy or kinetic analysis. The intricacy of the effects degrading nuclear medicine images and the lack of availability of adequate methods to compensate for these effects have frequently been seen as insurmountable obstacles in the use of quantitative nuclear medicine in clinical institutions. In the last few decades, several research groups have consistently devoted their efforts to the filling of these gaps. As a result, many efficient methods are now available that make quantification a clinical reality, provided appropriate compensation tools are used. Despite these efforts, many clinical institutions still lack the knowledge and tools to adequately measure and estimate the accumulated activities in the human body, thereby using potentially outdated protocols and procedures. The purpose of the present publication is to review the current state of the art of image quantification and to provide medical physicists and other related professionals facing quantification tasks with a solid background of tools and methods. It describes and analyses the physical effects that degrade image quality and affect the accuracy of quantification, and describes methods to compensate for them in planar, single photon emission computed tomography (SPECT) and positron emission tomography (PET) images. The fast paced development of the computational infrastructure, both hardware and software, has made drastic changes in the ways image quantification is now performed. The measuring equipment has evolved from the simple blind probes to planar and three dimensional imaging, supported by SPECT, PET and hybrid equipment. Methods of iterative reconstruction have been developed to allow for

  19. Robust and efficient method for matching features in omnidirectional images

    Science.gov (United States)

    Zhu, Qinyi; Zhang, Zhijiang; Zeng, Dan

    2018-04-01

    Binary descriptors have been widely used in many real-time applications due to their efficiency. These descriptors are commonly designed for perspective images but perform poorly on omnidirectional images, which are severely distorted. To address this issue, this paper proposes tangent plane BRIEF (TPBRIEF) and adapted log polar grid-based motion statistics (ALPGMS). TPBRIEF projects keypoints to a unit sphere and applies the fixed test set in BRIEF descriptor on the tangent plane of the unit sphere. The fixed test set is then backprojected onto the original distorted images to construct the distortion invariant descriptor. TPBRIEF directly enables keypoint detecting and feature describing on original distorted images, whereas other approaches correct the distortion through image resampling, which introduces artifacts and adds time cost. With ALPGMS, omnidirectional images are divided into circular arches named adapted log polar grids. Whether a match is true or false is then determined by simply thresholding the match numbers in a grid pair where the two matched points located. Experiments show that TPBRIEF greatly improves the feature matching accuracy and ALPGMS robustly removes wrong matches. Our proposed method outperforms the state-of-the-art methods.

  20. MR imaging methods for assessing fetal brain development.

    Science.gov (United States)

    Rutherford, Mary; Jiang, Shuzhou; Allsop, Joanna; Perkins, Lucinda; Srinivasan, Latha; Hayat, Tayyib; Kumar, Sailesh; Hajnal, Jo

    2008-05-01

    Fetal magnetic resonance imaging provides an ideal tool for investigating growth and development of the brain in vivo. Current imaging methods have been hampered by fetal motion but recent advances in image acquisition can produce high signal to noise, high resolution 3-dimensional datasets suitable for objective quantification by state of the art post acquisition computer programs. Continuing development of imaging techniques will allow a unique insight into the developing brain, more specifically process of cell migration, axonal pathway formation, and cortical maturation. Accurate quantification of these developmental processes in the normal fetus will allow us to identify subtle deviations from normal during the second and third trimester of pregnancy either in the compromised fetus or in infants born prematurely.

  1. A proposed assessment method for image of regional educational institutions

    Directory of Open Access Journals (Sweden)

    Kataeva Natalya

    2017-01-01

    Full Text Available Market of educational services in the current Russian economic conditions is a complex of a huge variety of educational institutions. Market of educational services is already experiencing a significant influence of the demographic situation in Russia. This means that higher education institutions are forced to fight in a tough competition for high school students. Increased competition in the educational market forces universities to find new methods of non-price competition in attraction of potential students and throughout own educational and economic activities. Commercialization of education places universities in a single plane with commercial companies who study a positive perception of the image and reputation as a competitive advantage, which is quite acceptable for use in strategic and current activities of higher education institutions to ensure the competitiveness of educational services and educational institution in whole. Nevertheless, due to lack of evidence-based proposals in this area there is a need for scientific research in terms of justification of organizational and methodological aspects of image use as a factor in the competitiveness of the higher education institution. Theoretically and practically there are different methods and ways of evaluating the company’s image. The article provides a comparative assessment of the existing valuation methods of corporate image and the author’s method of estimating the image of higher education institutions based on the key influencing factors. The method has been tested on the Vyatka State Agricultural Academy (Russia. The results also indicate the strengths and weaknesses of the institution, highlights ways of improving, and adjusts the efforts for image improvement.

  2. Guidance for Methods Descriptions Used in Preclinical Imaging Papers

    Directory of Open Access Journals (Sweden)

    David Stout

    2013-10-01

    Full Text Available Preclinical molecular imaging is a rapidly growing field, where new imaging systems, methods, and biological findings are constantly being developed or discovered. Imaging systems and the associated software usually have multiple options for generating data, which is often overlooked but is essential when reporting the methods used to create and analyze data. Similarly, the ways in which animals are housed, handled, and treated to create physiologically based data must be well described in order that the findings be relevant, useful, and reproducible. There are frequently new developments for metabolic imaging methods. Thus, specific reporting requirements are difficult to establish; however, it remains essential to adequately report how the data have been collected, processed, and analyzed. To assist with future manuscript submissions, this article aims to provide guidelines of what details to report for several of the most common imaging modalities. Examples are provided in an attempt to give comprehensive, succinct descriptions of the essential items to report about the experimental process.

  3. Novel axolotl cardiac function analysis method using magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Pedro Gomes Sanches

    Full Text Available The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a non-invasive technique to image heart function of axolotls. Three axolotls were imaged with magnetic resonance imaging using a retrospectively gated Fast Low Angle Shot cine sequence. Within one scanning session the axolotl heart was imaged three times in all planes, consecutively. Heart rate, ejection fraction, stroke volume and cardiac output were calculated using three techniques: (1 combined long-axis, (2 short-axis series, and (3 ultrasound (control for heart rate only. All values are presented as mean ± standard deviation. Heart rate (beats per minute among different animals was 32.2±6.0 (long axis, 30.4±5.5 (short axis and 32.7±4.9 (ultrasound and statistically similar regardless of the imaging method (p > 0.05. Ejection fraction (% was 59.6±10.8 (long axis and 48.1±11.3 (short axis and it differed significantly (p = 0.019. Stroke volume (μl/beat was 133.7±33.7 (long axis and 93.2±31.2 (short axis, also differed significantly (p = 0.015. Calculations were consistent among the animals and over three repeated measurements. The heart rate varied depending on depth of anaesthesia. We described a new method for defining and imaging the anatomical planes of the axolotl heart and propose one of our techniques (long axis analysis may prove useful in defining cardiac function in regenerating axolotl hearts.

  4. Elicited vs. voluntary promises

    NARCIS (Netherlands)

    Ismayilov, H.; Potters, Jan

    2017-01-01

    We set up an experiment with pre-play communication to study the impact of promise elicitation by trustors from trustees on trust and trustworthiness. When given the opportunity a majority of trustors solicits a promise from the trustee. This drives up the promise making rate by trustees to almost

  5. Informatics methods to enable sharing of quantitative imaging research data.

    Science.gov (United States)

    Levy, Mia A; Freymann, John B; Kirby, Justin S; Fedorov, Andriy; Fennessy, Fiona M; Eschrich, Steven A; Berglund, Anders E; Fenstermacher, David A; Tan, Yongqiang; Guo, Xiaotao; Casavant, Thomas L; Brown, Bartley J; Braun, Terry A; Dekker, Andre; Roelofs, Erik; Mountz, James M; Boada, Fernando; Laymon, Charles; Oborski, Matt; Rubin, Daniel L

    2012-11-01

    The National Cancer Institute Quantitative Research Network (QIN) is a collaborative research network whose goal is to share data, algorithms and research tools to accelerate quantitative imaging research. A challenge is the variability in tools and analysis platforms used in quantitative imaging. Our goal was to understand the extent of this variation and to develop an approach to enable sharing data and to promote reuse of quantitative imaging data in the community. We performed a survey of the current tools in use by the QIN member sites for representation and storage of their QIN research data including images, image meta-data and clinical data. We identified existing systems and standards for data sharing and their gaps for the QIN use case. We then proposed a system architecture to enable data sharing and collaborative experimentation within the QIN. There are a variety of tools currently used by each QIN institution. We developed a general information system architecture to support the QIN goals. We also describe the remaining architecture gaps we are developing to enable members to share research images and image meta-data across the network. As a research network, the QIN will stimulate quantitative imaging research by pooling data, algorithms and research tools. However, there are gaps in current functional requirements that will need to be met by future informatics development. Special attention must be given to the technical requirements needed to translate these methods into the clinical research workflow to enable validation and qualification of these novel imaging biomarkers. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. A novel magnetic resonance imaging-compatible motor control method for image-guided robotic surgery

    International Nuclear Information System (INIS)

    Suzuki, Takashi; Liao, Hongen; Kobayashi, Etsuko; Sakuma, Ichiro

    2006-01-01

    For robotic surgery assistance systems that use magnetic resonance imaging (MRI) for guidance, the problem of electromagnetic interference is common. Image quality is particularly degraded if motors are running during scanning. We propose a novel MRI-compatible method considering the pulse sequence of imaging. Motors are driven for a short time when the MRI system stops signal acquisition (i.e., awaiting relaxation of the proton), so the image does not contain noise from the actuators. The MRI system and motor are synchronized using a radio frequency pulse signal (8.5 MHz) as the trigger, which is acquired via a special antenna mounted near the scanner. This method can be widely applied because it only receives part of the scanning signal and neither hardware nor software of the MRI system needs to be changed. As a feasibility evaluation test, we compared the images and signal-to-noise ratios between the cases with and without this method, under the condition that a piezoelectric motor was driven during scanning as a noise source, which was generally used as a MRI-compatible actuator. The results showed no deterioration in image quality and the benefit of the new method even though the choice of available scanning sequences is limited. (author)

  7. Neutron imaging integrated circuit and method for detecting neutrons

    Science.gov (United States)

    Nagarkar, Vivek V.; More, Mitali J.

    2017-12-05

    The present disclosure provides a neutron imaging detector and a method for detecting neutrons. In one example, a method includes providing a neutron imaging detector including plurality of memory cells and a conversion layer on the memory cells, setting one or more of the memory cells to a first charge state, positioning the neutron imaging detector in a neutron environment for a predetermined time period, and reading a state change at one of the memory cells, and measuring a charge state change at one of the plurality of memory cells from the first charge state to a second charge state less than the first charge state, where the charge state change indicates detection of neutrons at said one of the memory cells.

  8. Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE): Proposed miTNM Classification for the Interpretation of PSMA-Ligand PET/CT.

    Science.gov (United States)

    Eiber, Matthias; Herrmann, Ken; Calais, Jeremie; Hadaschik, Boris; Giesel, Frederik L; Hartenbach, Markus; Hope, Thomas; Reiter, Robert; Maurer, Tobias; Weber, Wolfgang A; Fendler, Wolfgang P

    2018-03-01

    Prostate-specific membrane antigen (PSMA)-ligand PET imaging provides unprecedented accuracy for whole-body staging of prostate cancer. As PSMA-ligand PET/CT is increasingly adopted in clinical trials and routine practice worldwide, a unified language for image reporting is urgently needed. We propose a molecular imaging TNM system (miTNM, version 1.0) as a standardized reporting framework for PSMA-ligand PET/CT or PET/MRI. miTNM is designed to organize findings in comprehensible categories to promote the exchange of information among physicians and institutions. Additionally, flowcharts integrating findings of PSMA-ligand PET and morphologic imaging have been designed to guide image interpretation. Specific applications, such as assessment of prognosis or impact on management, should be evaluated in future trials. miTNM is a living framework that evolves with clinical experience and scientific data. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

  9. Integration of image exposure time into a modified laser speckle imaging method

    Energy Technology Data Exchange (ETDEWEB)

    RamIrez-San-Juan, J C; Salazar-Hermenegildo, N; Ramos-Garcia, R; Munoz-Lopez, J [Optics Department, INAOE, Puebla (Mexico); Huang, Y C [Department of Electrical Engineering and Computer Science, University of California, Irvine, CA (United States); Choi, B, E-mail: jcram@inaoep.m [Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA (United States)

    2010-11-21

    Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

  10. Integration of image exposure time into a modified laser speckle imaging method

    International Nuclear Information System (INIS)

    RamIrez-San-Juan, J C; Salazar-Hermenegildo, N; Ramos-Garcia, R; Munoz-Lopez, J; Huang, Y C; Choi, B

    2010-01-01

    Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

  11. Method of image segmentation using a neural network. Application to MR imaging of brain tumors

    International Nuclear Information System (INIS)

    Engler, E.; Gautherie, M.

    1992-01-01

    An original method of numerical images segmentation has been developed. This method is based on pixel clustering using a formal neural network configurated by supervised learning of pre-classified examples. The method has been applied to series of MR images of brain tumors (gliomas) with a view to proceed with a 3D-extraction of the tumor volume. This study is part of a project on cancer thermotherapy including the development of a scan-focused ultrasound system of tumor heating and a 3D-numerical thermal model

  12. An improved image non-blind image deblurring method based on FoEs

    Science.gov (United States)

    Zhu, Qidan; Sun, Lei

    2013-03-01

    Traditional non-blind image deblurring algorithms always use maximum a posterior(MAP). MAP estimates involving natural image priors can reduce the ripples effectively in contrast to maximum likelihood(ML). However, they have been found lacking in terms of restoration performance. Based on this issue, we utilize MAP with KL penalty to replace traditional MAP. We develop an image reconstruction algorithm that minimizes the KL divergence between the reference distribution and the prior distribution. The approximate KL penalty can restrain over-smooth caused by MAP. We use three groups of images and Harris corner detection to prove our method. The experimental results show that our algorithm of non-blind image restoration can effectively reduce the ringing effect and exhibit the state-of-the-art deblurring results.

  13. Sampling methods for low-frequency electromagnetic imaging

    International Nuclear Information System (INIS)

    Gebauer, Bastian; Hanke, Martin; Schneider, Christoph

    2008-01-01

    For the detection of hidden objects by low-frequency electromagnetic imaging the linear sampling method works remarkably well despite the fact that the rigorous mathematical justification is still incomplete. In this work, we give an explanation for this good performance by showing that in the low-frequency limit the measurement operator fulfils the assumptions for the fully justified variant of the linear sampling method, the so-called factorization method. We also show how the method has to be modified in the physically relevant case of electromagnetic imaging with divergence-free currents. We present numerical results to illustrate our findings, and to show that similar performance can be expected for the case of conducting objects and layered backgrounds

  14. Optimized optical clearing method for imaging central nervous system

    Science.gov (United States)

    Yu, Tingting; Qi, Yisong; Gong, Hui; Luo, Qingming; Zhu, Dan

    2015-03-01

    The development of various optical clearing methods provides a great potential for imaging entire central nervous system by combining with multiple-labelling and microscopic imaging techniques. These methods had made certain clearing contributions with respective weaknesses, including tissue deformation, fluorescence quenching, execution complexity and antibody penetration limitation that makes immunostaining of tissue blocks difficult. The passive clarity technique (PACT) bypasses those problems and clears the samples with simple implementation, excellent transparency with fine fluorescence retention, but the passive tissue clearing method needs too long time. In this study, we not only accelerate the clearing speed of brain blocks but also preserve GFP fluorescence well by screening an optimal clearing temperature. The selection of proper temperature will make PACT more applicable, which evidently broaden the application range of this method.

  15. Review of quantitative phase-digital holographic microscopy: promising novel imaging technique to resolve neuronal network activity and identify cellular biomarkers of psychiatric disorders

    KAUST Repository

    Marquet, Pierre

    2014-09-22

    Quantitative phase microscopy (QPM) has recently emerged as a new powerful quantitative imaging technique well suited to noninvasively explore a transparent specimen with a nanometric axial sensitivity. In this review, we expose the recent developments of quantitative phase-digital holographic microscopy (QP-DHM). Quantitative phase-digital holographic microscopy (QP-DHM) represents an important and efficient quantitative phase method to explore cell structure and dynamics. In a second part, the most relevant QPM applications in the field of cell biology are summarized. A particular emphasis is placed on the original biological information, which can be derived from the quantitative phase signal. In a third part, recent applications obtained, with QP-DHM in the field of cellular neuroscience, namely the possibility to optically resolve neuronal network activity and spine dynamics, are presented. Furthermore, potential applications of QPM related to psychiatry through the identification of new and original cell biomarkers that, when combined with a range of other biomarkers, could significantly contribute to the determination of high risk developmental trajectories for psychiatric disorders, are discussed.

  16. Image segmentation and particles classification using texture analysis method

    Directory of Open Access Journals (Sweden)

    Mayar Aly Atteya

    Full Text Available Introduction: Ingredients of oily fish include a large amount of polyunsaturated fatty acids, which are important elements in various metabolic processes of humans, and have also been used to prevent diseases. However, in an attempt to reduce cost, recent developments are starting a replace the ingredients of fish oil with products of microalgae, that also produce polyunsaturated fatty acids. To do so, it is important to closely monitor morphological changes in algae cells and monitor their age in order to achieve the best results. This paper aims to describe an advanced vision-based system to automatically detect, classify, and track the organic cells using a recently developed SOPAT-System (Smart On-line Particle Analysis Technology, a photo-optical image acquisition device combined with innovative image analysis software. Methods The proposed method includes image de-noising, binarization and Enhancement, as well as object recognition, localization and classification based on the analysis of particles’ size and texture. Results The methods allowed for correctly computing cell’s size for each particle separately. By computing an area histogram for the input images (1h, 18h, and 42h, the variation could be observed showing a clear increase in cell. Conclusion The proposed method allows for algae particles to be correctly identified with accuracies up to 99% and classified correctly with accuracies up to 100%.

  17. Electrodynamics, Differential Forms and the Method of Images

    Science.gov (United States)

    Low, Robert J.

    2011-01-01

    This paper gives a brief description of how Maxwell's equations are expressed in the language of differential forms and use this to provide an elegant demonstration of how the method of images (well known in electrostatics) also works for electrodynamics in the presence of an infinite plane conducting boundary. The paper should be accessible to an…

  18. The iterative shrinkage method for impulsive noise reduction from images

    International Nuclear Information System (INIS)

    Beygi, Sajjad; Kafashan, Mohammadmehdi; Bahrami, Hamid Reza; Mugler, Dale H

    2012-01-01

    In this paper, we present a novel scheme to compensate impulsive noise from images using the sparse shrinkage method. In this scheme, we assume the remaining noise after using a simple median filtering in place of corrupted pixels, found by boundary discriminative noise detection method, to be Gaussian additive noise. This assumption will later be verified by the means of simulation. Knowing that the pure image in the discrete wavelet transform (DWT) domain is a sparse vector, we define an optimization problem to minimize the l 0 -norm of the estimated image vector from the noisy one in the DWT domain. l 0 -norm makes the optimization problem a combinatorial optimization problem which is NP-hard to solve. To come up with a solution for our optimization problem, we convert the l 0 -norm problem to a continuous optimization problem which is then solved to find the estimated image with reduced noise. In the simulation and discussion part, the performance of our proposed method in reducing impulsive noise is compared to that of existing methods in the literature. We show that our proposed algorithm generally performs better in terms of both subjective and objective evaluations and is less complex. (paper)

  19. a Hyperspectral Image Classification Method Using Isomap and Rvm

    Science.gov (United States)

    Chang, H.; Wang, T.; Fang, H.; Su, Y.

    2018-04-01

    Classification is one of the most significant applications of hyperspectral image processing and even remote sensing. Though various algorithms have been proposed to implement and improve this application, there are still drawbacks in traditional classification methods. Thus further investigations on some aspects, such as dimension reduction, data mining, and rational use of spatial information, should be developed. In this paper, we used a widely utilized global manifold learning approach, isometric feature mapping (ISOMAP), to address the intrinsic nonlinearities of hyperspectral image for dimension reduction. Considering the impropriety of Euclidean distance in spectral measurement, we applied spectral angle (SA) for substitute when constructed the neighbourhood graph. Then, relevance vector machines (RVM) was introduced to implement classification instead of support vector machines (SVM) for simplicity, generalization and sparsity. Therefore, a probability result could be obtained rather than a less convincing binary result. Moreover, taking into account the spatial information of the hyperspectral image, we employ a spatial vector formed by different classes' ratios around the pixel. At last, we combined the probability results and spatial factors with a criterion to decide the final classification result. To verify the proposed method, we have implemented multiple experiments with standard hyperspectral images compared with some other methods. The results and different evaluation indexes illustrated the effectiveness of our method.

  20. Applications of γ-ray image method to astronomy

    International Nuclear Information System (INIS)

    Wuensche, C.A.; Braga, J.; Jayanthi, U.B.; Villela, T.

    1990-01-01

    The use of codified mask technique in a gamma ray telescope is presented. The image reconstruction method is described showing the mask operation. The signal/noise relation for redundant uniform arrangements which constitute the mask, is discussed. The MASCO telescope is described in detail showing the main characteristics of project. (M.C.K.)

  1. Monitoring a chemical plume remediation via the radio imaging method

    International Nuclear Information System (INIS)

    McCorkle, R.W.; Spence, T.; Linder, K.E.; Betsill, J.D.

    1996-01-01

    In this paper, the authors present the results of a site characterization, monitoring, and remediation effort at Sandia National Laboratories (SNL). The primary objective of the study is to determine the feasibility of using the Radio Imaging Method (RIM) to solve a near-surface waste site characterization problem. The goals are to demonstrate the method during the site characterization phase, then continue with an in-situ monitoring and analysis of the remediation process

  2. A Classification-oriented Method of Feature Image Generation for Vehicle-borne Laser Scanning Point Clouds

    Directory of Open Access Journals (Sweden)

    YANG Bisheng

    2016-02-01

    Full Text Available An efficient method of feature image generation of point clouds to automatically classify dense point clouds into different categories is proposed, such as terrain points, building points. The method first uses planar projection to sort points into different grids, then calculates the weights and feature values of grids according to the distribution of laser scanning points, and finally generates the feature image of point clouds. Thus, the proposed method adopts contour extraction and tracing means to extract the boundaries and point clouds of man-made objects (e.g. buildings and trees in 3D based on the image generated. Experiments show that the proposed method provides a promising solution for classifying and extracting man-made objects from vehicle-borne laser scanning point clouds.

  3. A single-image method of aberration retrieval for imaging systems under partially coherent illumination

    International Nuclear Information System (INIS)

    Xu, Shuang; Liu, Shiyuan; Zhang, Chuanwei; Wei, Haiqing

    2014-01-01

    We propose a method for retrieving small lens aberrations in optical imaging systems under partially coherent illumination, which only requires to measure one single defocused image of intensity. By deriving a linear theory of imaging systems, we obtain a generalized formulation of aberration sensitivity in a matrix form, which provides a set of analytic kernels that relate the measured intensity distribution directly to the unknown Zernike coefficients. Sensitivity analysis is performed and test patterns are optimized to ensure well-posedness of the inverse problem. Optical lithography simulations have validated the theoretical derivation and confirmed its simplicity and superior performance in retrieving small lens aberrations. (fast track communication)

  4. Development of CCD Imaging System Using Thermoelectric Cooling Method

    Directory of Open Access Journals (Sweden)

    Youngsik Park

    2000-06-01

    Full Text Available We developed low light CCD imaging system using thermoelectric cooling method collaboration with a company to design a commercial model. It consists of Kodak KAF-0401E (768x512 pixels CCD chip,thermoelectric module manufactured by Thermotek. This TEC system can reach an operative temperature of -25deg. We employed an Uniblitz VS25S shutter and it has capability a minimum exposure time 80ms. The system components are an interface card using a Korea Astronomy Observatory (hereafter KAO ISA bus controller, image acquisition with AD9816 chip, that is 12bit video processor. The performance test with this imaging system showed good operation within the initial specification of our design. It shows a dark current less than 0.4e-/pixel/sec at a temperature of -10deg, a linearity 99.9+/-0.1%, gain 4.24e-adu, and system noise is 25.3e- (rms. For low temperature CCD operation, we designed a TEC, which uses a one-stage peltier module and forced air heat exchanger. This TEC imaging system enables accurate photometry (+/-0.01mag even though the CCD is not at 'conventional' cryogenic temperatures (140K. The system can be a useful instrument for any other imaging applications. Finally, with this system, we obtained several images of astronomical objects for system performance tests.

  5. Influence of image reconstruction methods on statistical parametric mapping of brain PET images

    International Nuclear Information System (INIS)

    Yin Dayi; Chen Yingmao; Yao Shulin; Shao Mingzhe; Yin Ling; Tian Jiahe; Cui Hongyan

    2007-01-01

    Objective: Statistic parametric mapping (SPM) was widely recognized as an useful tool in brain function study. The aim of this study was to investigate if imaging reconstruction algorithm of PET images could influence SPM of brain. Methods: PET imaging of whole brain was performed in six normal volunteers. Each volunteer had two scans with true and false acupuncturing. The PET scans were reconstructed using ordered subsets expectation maximization (OSEM) and filtered back projection (FBP) with 3 varied parameters respectively. The images were realigned, normalized and smoothed using SPM program. The difference between true and false acupuncture scans was tested using a matched pair t test at every voxel. Results: (1) SPM corrected multiple comparison (P corrected uncorrected <0.001): SPM derived from the images with different reconstruction method were different. The largest difference, in number and position of the activated voxels, was noticed between FBP and OSEM re- construction algorithm. Conclusions: The method of PET image reconstruction could influence the results of SPM uncorrected multiple comparison. Attention should be paid when the conclusion was drawn using SPM uncorrected multiple comparison. (authors)

  6. Automated segmentation and isolation of touching cell nuclei in cytopathology smear images of pleural effusion using distance transform watershed method

    Science.gov (United States)

    Win, Khin Yadanar; Choomchuay, Somsak; Hamamoto, Kazuhiko

    2017-06-01

    The automated segmentation of cell nuclei is an essential stage in the quantitative image analysis of cell nuclei extracted from smear cytology images of pleural fluid. Cell nuclei can indicate cancer as the characteristics of cell nuclei are associated with cells proliferation and malignancy in term of size, shape and the stained color. Nevertheless, automatic nuclei segmentation has remained challenging due to the artifacts caused by slide preparation, nuclei heterogeneity such as the poor contrast, inconsistent stained color, the cells variation, and cells overlapping. In this paper, we proposed a watershed-based method that is capable to segment the nuclei of the variety of cells from cytology pleural fluid smear images. Firstly, the original image is preprocessed by converting into the grayscale image and enhancing by adjusting and equalizing the intensity using histogram equalization. Next, the cell nuclei are segmented using OTSU thresholding as the binary image. The undesirable artifacts are eliminated using morphological operations. Finally, the distance transform based watershed method is applied to isolate the touching and overlapping cell nuclei. The proposed method is tested with 25 Papanicolaou (Pap) stained pleural fluid images. The accuracy of our proposed method is 92%. The method is relatively simple, and the results are very promising.

  7. Cost calculator methods for estimating casework time in child welfare services: A promising approach for use in implementation of evidence-based practices and other service innovations.

    Science.gov (United States)

    Holmes, Lisa; Landsverk, John; Ward, Harriet; Rolls-Reutz, Jennifer; Saldana, Lisa; Wulczyn, Fred; Chamberlain, Patricia

    2014-04-01

    Estimating costs in child welfare services is critical as new service models are incorporated into routine practice. This paper describes a unit costing estimation system developed in England (cost calculator) together with a pilot test of its utility in the United States where unit costs are routinely available for health services but not for child welfare services. The cost calculator approach uses a unified conceptual model that focuses on eight core child welfare processes. Comparison of these core processes in England and in four counties in the United States suggests that the underlying child welfare processes generated from England were perceived as very similar by child welfare staff in California county systems with some exceptions in the review and legal processes. Overall, the adaptation of the cost calculator for use in the United States child welfare systems appears promising. The paper also compares the cost calculator approach to the workload approach widely used in the United States and concludes that there are distinct differences between the two approaches with some possible advantages to the use of the cost calculator approach, especially in the use of this method for estimating child welfare costs in relation to the incorporation of evidence-based interventions into routine practice.

  8. Fast nonconvex nonsmooth minimization methods for image restoration and reconstruction.

    Science.gov (United States)

    Nikolova, Mila; Ng, Michael K; Tam, Chi-Pan

    2010-12-01

    Nonconvex nonsmooth regularization has advantages over convex regularization for restoring images with neat edges. However, its practical interest used to be limited by the difficulty of the computational stage which requires a nonconvex nonsmooth minimization. In this paper, we deal with nonconvex nonsmooth minimization methods for image restoration and reconstruction. Our theoretical results show that the solution of the nonconvex nonsmooth minimization problem is composed of constant regions surrounded by closed contours and neat edges. The main goal of this paper is to develop fast minimization algorithms to solve the nonconvex nonsmooth minimization problem. Our experimental results show that the effectiveness and efficiency of the proposed algorithms.

  9. Single photon imaging and timing array sensor apparatus and method

    Science.gov (United States)

    Smith, R. Clayton

    2003-06-24

    An apparatus and method are disclosed for generating a three-dimension image of an object or target. The apparatus is comprised of a photon source for emitting a photon at a target. The emitted photons are received by a photon receiver for receiving the photon when reflected from the target. The photon receiver determines a reflection time of the photon and further determines an arrival position of the photon on the photon receiver. An analyzer is communicatively coupled to the photon receiver, wherein the analyzer generates a three-dimensional image of the object based upon the reflection time and the arrival position.

  10. Method of imaging the electrical conductivity distribution of a subsurface

    Science.gov (United States)

    Johnson, Timothy C.

    2017-09-26

    A method of imaging electrical conductivity distribution of a subsurface containing metallic structures with known locations and dimensions is disclosed. Current is injected into the subsurface to measure electrical potentials using multiple sets of electrodes, thus generating electrical resistivity tomography measurements. A numeric code is applied to simulate the measured potentials in the presence of the metallic structures. An inversion code is applied that utilizes the electrical resistivity tomography measurements and the simulated measured potentials to image the subsurface electrical conductivity distribution and remove effects of the subsurface metallic structures with known locations and dimensions.

  11. Interpolation decoding method with variable parameters for fractal image compression

    International Nuclear Information System (INIS)

    He Chuanjiang; Li Gaoping; Shen Xiaona

    2007-01-01

    The interpolation fractal decoding method, which is introduced by [He C, Yang SX, Huang X. Progressive decoding method for fractal image compression. IEE Proc Vis Image Signal Process 2004;3:207-13], involves generating progressively the decoded image by means of an interpolation iterative procedure with a constant parameter. It is well-known that the majority of image details are added at the first steps of iterations in the conventional fractal decoding; hence the constant parameter for the interpolation decoding method must be set as a smaller value in order to achieve a better progressive decoding. However, it needs to take an extremely large number of iterations to converge. It is thus reasonable for some applications to slow down the iterative process at the first stages of decoding and then to accelerate it afterwards (e.g., at some iteration as we need). To achieve the goal, this paper proposed an interpolation decoding scheme with variable (iteration-dependent) parameters and proved the convergence of the decoding process mathematically. Experimental results demonstrate that the proposed scheme has really achieved the above-mentioned goal

  12. Cardiodiagnostic imaging. MRT, CT, echocardiography and other methods

    International Nuclear Information System (INIS)

    Erbel, R.; Kreitner, K.F.; Barkhausen, J.; Thelen, M.

    2007-01-01

    The book presents a differentiated approach to cardiac imaging. The focus is n cardio-MR/-CT and echocardiography. These are highly complex methods involving new equipment, new protocols and indications. The techniques are new and difficult to learn for everybody concerned. MR, CT and echocardiography must always be viewed in the context of other diagnostic methods. The interdisciplinary approach of the book addresses both radiologists and cardiologists and relies on the vast experience of the authors. The book offers more than 500 large high-quality reference images reflecting the latest state of the art. It has amethodological section in which the current methods are described (X-ray, echocardiography, nuclear medicine, angiography, CT, MRT etc.) along with their advantages and shortcomings, and a clinical section in which the main indications are described in the common standardized way (anatomy, clinical picture, interpretation, differential diagnosis). (orig.)

  13. Meshfree Local Radial Basis Function Collocation Method with Image Nodes

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seung Ki; Kim, Minjae [Pukyong National University, Busan (Korea, Republic of)

    2017-07-15

    We numerically solve two-dimensional heat diffusion problems by using a simple variant of the meshfree local radial-basis function (RBF) collocation method. The main idea is to include an additional set of sample nodes outside the problem domain, similarly to the method of images in electrostatics, to perform collocation on the domain boundaries. We can thereby take into account the temperature profile as well as its gradients specified by boundary conditions at the same time, which holds true even for a node where two or more boundaries meet with different boundary conditions. We argue that the image method is computationally efficient when combined with the local RBF collocation method, whereas the addition of image nodes becomes very costly in case of the global collocation. We apply our modified method to a benchmark test of a boundary value problem, and find that this simple modification reduces the maximum error from the analytic solution significantly. The reduction is small for an initial value problem with simpler boundary conditions. We observe increased numerical instability, which has to be compensated for by a sufficient number of sample nodes and/or more careful parameter choices for time integration.

  14. The gridding method for image reconstruction by Fourier transformation

    International Nuclear Information System (INIS)

    Schomberg, H.; Timmer, J.

    1995-01-01

    This paper explores a computational method for reconstructing an n-dimensional signal f from a sampled version of its Fourier transform f. The method involves a window function w and proceeds in three steps. First, the convolution g = w * f is computed numerically on a Cartesian grid, using the available samples of f. Then, g = wf is computed via the inverse discrete Fourier transform, and finally f is obtained as g/w. Due to the smoothing effect of the convolution, evaluating w * f is much less error prone than merely interpolating f. The method was originally devised for image reconstruction in radio astronomy, but is actually applicable to a broad range of reconstructive imaging methods, including magnetic resonance imaging and computed tomography. In particular, it provides a fast and accurate alternative to the filtered backprojection. The basic method has several variants with other applications, such as the equidistant resampling of arbitrarily sampled signals or the fast computation of the Radon (Hough) transform

  15. Total variation superiorized conjugate gradient method for image reconstruction

    Science.gov (United States)

    Zibetti, Marcelo V. W.; Lin, Chuan; Herman, Gabor T.

    2018-03-01

    The conjugate gradient (CG) method is commonly used for the relatively-rapid solution of least squares problems. In image reconstruction, the problem can be ill-posed and also contaminated by noise; due to this, approaches such as regularization should be utilized. Total variation (TV) is a useful regularization penalty, frequently utilized in image reconstruction for generating images with sharp edges. When a non-quadratic norm is selected for regularization, as is the case for TV, then it is no longer possible to use CG. Non-linear CG is an alternative, but it does not share the efficiency that CG shows with least squares and methods such as fast iterative shrinkage-thresholding algorithms (FISTA) are preferred for problems with TV norm. A different approach to including prior information is superiorization. In this paper it is shown that the conjugate gradient method can be superiorized. Five different CG variants are proposed, including preconditioned CG. The CG methods superiorized by the total variation norm are presented and their performance in image reconstruction is demonstrated. It is illustrated that some of the proposed variants of the superiorized CG method can produce reconstructions of superior quality to those produced by FISTA and in less computational time, due to the speed of the original CG for least squares problems. In the Appendix we examine the behavior of one of the superiorized CG methods (we call it S-CG); one of its input parameters is a positive number ɛ. It is proved that, for any given ɛ that is greater than the half-squared-residual for the least squares solution, S-CG terminates in a finite number of steps with an output for which the half-squared-residual is less than or equal to ɛ. Importantly, it is also the case that the output will have a lower value of TV than what would be provided by unsuperiorized CG for the same value ɛ of the half-squared residual.

  16. The method of images and Green's function for spherical domains

    International Nuclear Information System (INIS)

    Gutkin, Eugene; Newton, Paul K

    2004-01-01

    Motivated by problems in electrostatics and vortex dynamics, we develop two general methods for constructing Green's function for simply connected domains on the surface of the unit sphere. We prove a Riemann mapping theorem showing that such domains can be conformally mapped to the upper hemisphere. We then categorize all domains on the sphere for which Green's function can be constructed by an extension of the classical method of images. We illustrate our methods by several examples, such as the upper hemisphere, geodesic triangles, and latitudinal rectangles. We describe the point vortex motion in these domains, which is governed by a Hamiltonian determined by the Dirichlet Green's function

  17. The best printing methods to print satellite images

    Directory of Open Access Journals (Sweden)

    G.A. Yousif

    2011-12-01

    In this paper different printing systems were used to print an image of SPOT-4 satellite, caver part of Sharm Elshekh area, Sinai, Egypt, on the same type of paper as much as possible, especially in the photography. This step is followed by measuring the experimental data, and analyzed colors to determine the best printing systems for satellite image printing data. The laser system is the more printing system where produce a wider range of color and highest densities of ink and access much color detail. Followed by the offset system which it recorded the best dot gain. Moreover, the study shows that it can use the advantages of each method according to the satellite image color and quantity to be produced.

  18. METHOD OF IMAGE QUALITY ENHANCEMENT FOR SPACE OBJECTS

    Directory of Open Access Journals (Sweden)

    D. S. Korshunov

    2014-07-01

    Full Text Available The paper deals with an approach for image quality improvement of the space objects in the visible range of electromagnetic wave spectrum. The proposed method is based on the joint taking into account of both the motion velocity of the space supervisory apparatus and a space object observed in the near-earth space when the time of photo-detector exposure is chosen. The timing of exposure is carried out by light-signal characteristics, which determines the optimal value of the charge package formed in the charge-coupled device being irradiated. Thus, the parameters of onboard observation equipment can be selected, which provides space images suitable for interpretation. The linear resolving capacity is used as quality indicator for space images, giving a complete picture for the image contrast and geometric properties of the object on the photo. Observation scenario modeling of the space object, done by sputnik-inspector, has shown the possibility of increasing the linear resolution up to10% - 20% or up to 40% - 50% depending on the non-complanarity angle at the movement along orbits. The proposed approach to the increase of photographs quality provides getting sharp and highcontrast images of space objects by the optical-electronic equipment of the space-based remote sensing. The usage of these images makes it possible to detect in time the space technology failures, which are the result of its exploitation in the nearearth space. The proposed method can be also applied at the stage of space systems design for optical-electronic surveillance in computer models used for facilities assessment of the shooting equipment information tract.

  19. Optical image encryption method based on incoherent imaging and polarized light encoding

    Science.gov (United States)

    Wang, Q.; Xiong, D.; Alfalou, A.; Brosseau, C.

    2018-05-01

    We propose an incoherent encoding system for image encryption based on a polarized encoding method combined with an incoherent imaging. Incoherent imaging is the core component of this proposal, in which the incoherent point-spread function (PSF) of the imaging system serves as the main key to encode the input intensity distribution thanks to a convolution operation. An array of retarders and polarizers is placed on the input plane of the imaging structure to encrypt the polarized state of light based on Mueller polarization calculus. The proposal makes full use of randomness of polarization parameters and incoherent PSF so that a multidimensional key space is generated to deal with illegal attacks. Mueller polarization calculus and incoherent illumination of imaging structure ensure that only intensity information is manipulated. Another key advantage is that complicated processing and recording related to a complex-valued signal are avoided. The encoded information is just an intensity distribution, which is advantageous for data storage and transition because information expansion accompanying conventional encryption methods is also avoided. The decryption procedure can be performed digitally or using optoelectronic devices. Numerical simulation tests demonstrate the validity of the proposed scheme.

  20. An automated image processing method for classification of diabetic retinopathy stages from conjunctival microvasculature images

    Science.gov (United States)

    Khansari, Maziyar M.; O'Neill, William; Penn, Richard; Blair, Norman P.; Chau, Felix; Shahidi, Mahnaz

    2017-03-01

    The conjunctiva is a densely vascularized tissue of the eye that provides an opportunity for imaging of human microcirculation. In the current study, automated fine structure analysis of conjunctival microvasculature images was performed to discriminate stages of diabetic retinopathy (DR). The study population consisted of one group of nondiabetic control subjects (NC) and 3 groups of diabetic subjects, with no clinical DR (NDR), non-proliferative DR (NPDR), or proliferative DR (PDR). Ordinary least square regression and Fisher linear discriminant analyses were performed to automatically discriminate images between group pairs of subjects. Human observers who were masked to the grouping of subjects performed image discrimination between group pairs. Over 80% and 70% of images of subjects with clinical and non-clinical DR were correctly discriminated by the automated method, respectively. The discrimination rates of the automated method were higher than human observers. The fine structure analysis of conjunctival microvasculature images provided discrimination of DR stages and can be potentially useful for DR screening and monitoring.

  1. Low voltage operation of electro-absorption modulator promising for high-definition 3D imaging application using a three step asymmetric coupled quantum well structure

    International Nuclear Information System (INIS)

    Na, Byung Hoon; Ju, Gun Wu; Cho, Yong Chul; Lee, Yong Tak; Choi, Hee Ju; Jeon, Jin Myeong; Lee, Soo Kyung; Park, Yong Hwa; Park, Chang Young

    2015-01-01

    In this paper, we propose a transmission type electro-absorption modulator (EAM) operating at 850 nm having low operating voltage and high absorption change with low insertion loss using a novel three step asymmetric coupled quantum well (3 ACQW) structure which can be used as an optical image shutter for high-definition (HD) three dimensional (3D) imaging. Theoretical calculations show that the exciton red shift of 3 ACQW structure is more than two times larger than that of rectangular quantum well (RQW) structure while maintaining high absorption change. The EAM having coupled cavities with 3 ACQW structure shows a wide spectral bandwidth and high amplitude modulation at a bias voltage of only -8V, which is 41% lower in operating voltage than that of RQW, making the proposed EAM highly attractive as an optical image shutter for HD 3D imaging applications

  2. Review of quantitative phase-digital holographic microscopy: promising novel imaging technique to resolve neuronal network activity and identify cellular biomarkers of psychiatric disorders

    KAUST Repository

    Marquet, Pierre; Depeursinge, Christian; Magistretti, Pierre J.

    2014-01-01

    Quantitative phase microscopy (QPM) has recently emerged as a new powerful quantitative imaging technique well suited to noninvasively explore a transparent specimen with a nanometric axial sensitivity. In this review, we expose the recent

  3. a Comparative Case Study of Reflection Seismic Imaging Method

    Science.gov (United States)

    Alamooti, M.; Aydin, A.

    2017-12-01

    Seismic imaging is the most common means of gathering information about subsurface structural features. The accuracy of seismic images may be highly variable depending on the complexity of the subsurface and on how seismic data is processed. One of the crucial steps in this process, especially in layered sequences with complicated structure, is the time and/or depth migration of seismic data.The primary purpose of the migration is to increase the spatial resolution of seismic images by repositioning the recorded seismic signal back to its original point of reflection in time/space, which enhances information about complex structure. In this study, our objective is to process a seismic data set (courtesy of the University of South Carolina) to generate an image on which the Magruder fault near Allendale SC can be clearly distinguished and its attitude can be accurately depicted. The data was gathered by common mid-point method with 60 geophones equally spaced along an about 550 m long traverse over a nearly flat ground. The results obtained from the application of different migration algorithms (including finite-difference and Kirchhoff) are compared in time and depth domains to investigate the efficiency of each algorithm in reducing the processing time and improving the accuracy of seismic images in reflecting the correct position of the Magruder fault.

  4. The evolving role of new imaging methods in breast screening.

    Science.gov (United States)

    Houssami, Nehmat; Ciatto, Stefano

    2011-09-01

    The potential to avert breast cancer deaths through screening means that efforts continue to identify methods which may enhance early detection. While the role of most new imaging technologies remains in adjunct screening or in the work-up of mammography-detected abnormalities, some of the new breast imaging tests (such as MRI) have roles in screening groups of women defined by increased cancer risk. This paper highlights the evidence and the current role of new breast imaging technologies in screening, focusing on those that have broader application in population screening, including digital mammography, breast ultrasound in women with dense breasts, and computer-aided detection. It highlights that evidence on new imaging in screening comes mostly from non-randomised studies that have quantified test detection capability as adjunct to mammography, or have compared measures of screening performance for new technologies with that of conventional mammography. Two RCTs have provided high-quality evidence on the equivalence of digital and conventional mammography and on outcomes of screen-reading complemented by CAD. Many of these imaging technologies enhance cancer detection but also increase recall and false positives in screening. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Ectomography - a tomographic method for gamma camera imaging

    International Nuclear Information System (INIS)

    Dale, S.; Edholm, P.E.; Hellstroem, L.G.; Larsson, S.

    1985-01-01

    In computerised gamma camera imaging the projections are readily obtained in digital form, and the number of picture elements may be relatively few. This condition makes emission techniques suitable for ectomography - a tomographic technique for directly visualising arbitrary sections of the human body. The camera rotates around the patient to acquire different projections in a way similar to SPECT. This method differs from SPECT, however, in that the camera is placed at an angle to the rotational axis, and receives two-dimensional, rather than one-dimensional, projections. Images of body sections are reconstructed by digital filtration and combination of the acquired projections. The main advantages of ectomography - a high and uniform resolution, a low and uniform attenuation and a high signal-to-noise ratio - are obtained when imaging sections close and parallel to a body surface. The filtration eliminates signals representing details outside the section and gives the section a certain thickness. Ectomographic transverse images of a line source and of a human brain have been reconstructed. Details within the sections are correctly visualised and details outside are effectively eliminated. For comparison, the same sections have been imaged with SPECT. (author)

  6. Quantitative magnetic resonance micro-imaging methods for pharmaceutical research.

    Science.gov (United States)

    Mantle, M D

    2011-09-30

    The use of magnetic resonance imaging (MRI) as a tool in pharmaceutical research is now well established and the current literature covers a multitude of different pharmaceutically relevant research areas. This review focuses on the use of quantitative magnetic resonance micro-imaging techniques and how they have been exploited to extract information that is of direct relevance to the pharmaceutical industry. The article is divided into two main areas. The first half outlines the theoretical aspects of magnetic resonance and deals with basic magnetic resonance theory, the effects of nuclear spin-lattice (T(1)), spin-spin (T(2)) relaxation and molecular diffusion upon image quantitation, and discusses the applications of rapid magnetic resonance imaging techniques. In addition to the theory, the review aims to provide some practical guidelines for the pharmaceutical researcher with an interest in MRI as to which MRI pulse sequences/protocols should be used and when. The second half of the article reviews the recent advances and developments that have appeared in the literature concerning the use of quantitative micro-imaging methods to pharmaceutically relevant research. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. A simple method for multiday imaging of slice cultures.

    Science.gov (United States)

    Seidl, Armin H; Rubel, Edwin W

    2010-01-01

    The organotypic slice culture (Stoppini et al. A simple method for organotypic cultures of nervous tissue. 1991;37:173-182) has become the method of choice to answer a variety of questions in neuroscience. For many experiments, however, it would be beneficial to image or manipulate a slice culture repeatedly, for example, over the course of many days. We prepared organotypic slice cultures of the auditory brainstem of P3 and P4 mice and kept them in vitro for up to 4 weeks. Single cells in the auditory brainstem were transfected with plasmids expressing fluorescent proteins by way of electroporation (Haas et al. Single-cell electroporation for gene transfer in vivo. 2001;29:583-591). The culture was then placed in a chamber perfused with oxygenated ACSF and the labeled cell imaged with an inverted wide-field microscope repeatedly for multiple days, recording several time-points per day, before returning the slice to the incubator. We describe a simple method to image a slice culture preparation during the course of multiple days and over many continuous hours, without noticeable damage to the tissue or photobleaching. Our method uses a simple, inexpensive custom-built insulator constructed around the microscope to maintain controlled temperature and uses a perfusion chamber as used for in vitro slice recordings. (c) 2009 Wiley-Liss, Inc.

  8. A method for dynamic subtraction MR imaging of the liver

    Directory of Open Access Journals (Sweden)

    Setti Ernesto

    2006-06-01

    Full Text Available Abstract Background Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time. Methods Nineteen consecutive patients (median age 45 years; range 37–67 were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20°, slice thickness 1.5 mm acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a rigid 3D translation using maximization of normalized mutual information (NMI, and (b fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI. Results The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 ± 0.031 vs. 0.078 ± 0.031, n.s., paired t-test and by a further 23% (0.096 ± 0.035 vs. 0.078 ± 0.031, p t-test after non-rigid realignment. The overall average NMI increase was 31%. Conclusion This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions.

  9. Brief review of image reconstruction methods for imaging in nuclear medicine

    International Nuclear Information System (INIS)

    Murayama, Hideo

    1999-01-01

    Emission computed tomography (ECT) has as its major emphasis the quantitative determination of the moment to moment changes in the chemistry and flow physiology of injected or inhaled compounds labeled with radioactive atoms in a human body. The major difference lies in the fact that ECT seeks to describe the location and intensity of sources of emitted photons in an attenuating medium whereas transmission X-ray computed tomography (TCT) seeks to determine the distribution of the attenuating medium. A second important difference between ECT and TCT is that of available statistics. ECT statistics are low because each photon without control in emitting direction must be detected and analyzed, not as in TCT. The following sections review the historical development of image reconstruction methods for imaging in nuclear medicine, relevant intrinsic concepts for image reconstruction on ECT, and current status of volume imaging as well as a unique approach on iterative techniques for ECT. (author). 130 refs

  10. Structured sparse canonical correlation analysis for brain imaging genetics: an improved GraphNet method.

    Science.gov (United States)

    Du, Lei; Huang, Heng; Yan, Jingwen; Kim, Sungeun; Risacher, Shannon L; Inlow, Mark; Moore, Jason H; Saykin, Andrew J; Shen, Li

    2016-05-15

    Structured sparse canonical correlation analysis (SCCA) models have been used to identify imaging genetic associations. These models either use group lasso or graph-guided fused lasso to conduct feature selection and feature grouping simultaneously. The group lasso based methods require prior knowledge to define the groups, which limits the capability when prior knowledge is incomplete or unavailable. The graph-guided methods overcome this drawback by using the sample correlation to define the constraint. However, they are sensitive to the sign of the sample correlation, which could introduce undesirable bias if the sign is wrongly estimated. We introduce a novel SCCA model with a new penalty, and develop an efficient optimization algorithm. Our method has a strong upper bound for the grouping effect for both positively and negatively correlated features. We show that our method performs better than or equally to three competing SCCA models on both synthetic and real data. In particular, our method identifies stronger canonical correlations and better canonical loading patterns, showing its promise for revealing interesting imaging genetic associations. The Matlab code and sample data are freely available at http://www.iu.edu/∼shenlab/tools/angscca/ shenli@iu.edu Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Imaging Method Based on Time Reversal Channel Compensation

    Directory of Open Access Journals (Sweden)

    Bing Li

    2015-01-01

    Full Text Available The conventional time reversal imaging (TRI method builds imaging function by using the maximal value of signal amplitude. In this circumstance, some remote targets are missed (near-far problem or low resolution is obtained in lossy and/or dispersive media, and too many transceivers are employed to locate targets, which increases the complexity and cost of system. To solve these problems, a novel TRI algorithm is presented in this paper. In order to achieve a high resolution, the signal amplitude corresponding to focal time observed at target position is used to reconstruct the target image. For disposing near-far problem and suppressing spurious images, combining with cross-correlation property and amplitude compensation, channel compensation function (CCF is introduced. Moreover, the complexity and cost of system are reduced by employing only five transceivers to detect four targets whose number is close to that of transceivers. For the sake of demonstrating the practicability of the proposed analytical framework, the numerical experiments are actualized in both nondispersive-lossless (NDL media and dispersive-conductive (DPC media. Results show that the performance of the proposed method is superior to that of conventional TRI algorithm even under few echo signals.

  12. Lung region extraction based on the model information and the inversed MIP method by using chest CT images

    International Nuclear Information System (INIS)

    Tomita, Toshihiro; Miguchi, Ryosuke; Okumura, Toshiaki; Yamamoto, Shinji; Matsumoto, Mitsuomi; Tateno, Yukio; Iinuma, Takeshi; Matsumoto, Toru.

    1997-01-01

    We developed a lung region extraction method based on the model information and the inversed MIP method in the Lung Cancer Screening CT (LSCT). Original model is composed of typical 3-D lung contour lines, a body axis, an apical point, and a convex hull. First, the body axis. the apical point, and the convex hull are automatically extracted from the input image Next, the model is properly transformed to fit to those of input image by the affine transformation. Using the same affine transformation coefficients, typical lung contour lines are also transferred, which correspond to rough contour lines of input image. Experimental results applied for 68 samples showed this method quite promising. (author)

  13. Method for imaging with low frequency electromagnetic fields

    Science.gov (United States)

    Lee, Ki H.; Xie, Gan Q.

    1994-01-01

    A method for imaging with low frequency electromagnetic fields, and for interpreting the electromagnetic data using ray tomography, in order to determine the earth conductivity with high accuracy and resolution. The imaging method includes the steps of placing one or more transmitters, at various positions in a plurality of transmitter holes, and placing a plurality of receivers in a plurality of receiver holes. The transmitters generate electromagnetic signals which diffuse through a medium, such as earth, toward the receivers. The measured diffusion field data H is then transformed into wavefield data U. The traveltimes corresponding to the wavefield data U, are then obtained, by charting the wavefield data U, using a different regularization parameter .alpha. for each transform. The desired property of the medium, such as conductivity, is then derived from the velocity, which in turn is constructed from the wavefield data U using ray tomography.

  14. Method and apparatus for animal positioning in imaging systems

    Science.gov (United States)

    Hadjioannou, Arion-Xenofon; Stout, David B.; Silverman, Robert W.

    2013-01-01

    An apparatus for imaging an animal includes a first mounting surface, a bed sized to support the animal and releasably secured to or integral with the first mounting surface. The apparatus also includes a plurality of straps, each having a first end in a fixed position relative to the bed and a second end for tightening around a limb of the animal. A method for in-vivo imaging of an animal includes providing an animal that has limbs, providing a first mounting surface, and providing a bed removably secured to or integral with the mounting surface and sized to support the animal as well as being coupled to a plurality of straps. The method also includes placing the animal on the bed between the plurality of straps and tightening at least two of the plurality of straps around at least two of the limbs such that the animal is substantially secured in place relative to the bed.

  15. A novel attack method about double-random-phase-encoding-based image hiding method

    Science.gov (United States)

    Xu, Hongsheng; Xiao, Zhijun; Zhu, Xianchen

    2018-03-01

    By using optical image processing techniques, a novel text encryption and hiding method applied by double-random phase-encoding technique is proposed in the paper. The first step is that the secret message is transformed into a 2-dimension array. The higher bits of the elements in the array are used to fill with the bit stream of the secret text, while the lower bits are stored specific values. Then, the transformed array is encoded by double random phase encoding technique. Last, the encoded array is embedded on a public host image to obtain the image embedded with hidden text. The performance of the proposed technique is tested via analytical modeling and test data stream. Experimental results show that the secret text can be recovered either accurately or almost accurately, while maintaining the quality of the host image embedded with hidden data by properly selecting the method of transforming the secret text into an array and the superimposition coefficient.

  16. A deep level set method for image segmentation

    OpenAIRE

    Tang, Min; Valipour, Sepehr; Zhang, Zichen Vincent; Cobzas, Dana; MartinJagersand

    2017-01-01

    This paper proposes a novel image segmentation approachthat integrates fully convolutional networks (FCNs) with a level setmodel. Compared with a FCN, the integrated method can incorporatesmoothing and prior information to achieve an accurate segmentation.Furthermore, different than using the level set model as a post-processingtool, we integrate it into the training phase to fine-tune the FCN. Thisallows the use of unlabeled data during training in a semi-supervisedsetting. Using two types o...

  17. A Method of Poisson's Ration Imaging Within a Material Part

    Science.gov (United States)

    Roth, Don J. (Inventor)

    1994-01-01

    The present invention is directed to a method of displaying the Poisson's ratio image of a material part. In the present invention, longitudinal data is produced using a longitudinal wave transducer and shear wave data is produced using a shear wave transducer. The respective data is then used to calculate the Poisson's ratio for the entire material part. The Poisson's ratio approximations are then used to display the data.

  18. A New Promising Technique of 3D Isovoxel Imaging Using 3T MRI in the Wrist: Comparison with 3T MR Arthrography

    International Nuclear Information System (INIS)

    Lee, Guen Young; Kim, Baek Hyun; Park, Jong Woong

    2011-01-01

    We wanted to evaluate the usefulness of 3D isovoxel MR imaging using 3T MRI in the wrist joint, as compared with 3T MR arthrography. A total of 33 patients underwent both MR arthrography and 3D isovoxel imaging of the wrist joints using 3T MR, including 11 patients with arthroscopic confirmation. 3D isovoxel MR imaging was performed using an intermediateweighted fast spin echo coronal scan with a 0.4-mm slice thickness and the axial images were reconstructed with a 1-mm slice thickness. One radiologist evaluated for the presence of scapholunate or lunotriquetral ligament tear and she determined the grade of the triangular fibrocartilage complex tear and chondromalacia with its location. We compared the two examinations using kappa values. The rates of detecting wrist injury were similar for both exams with substantial to almost perfect inter-examination agreement (kappa value = 0.864 for scapholunate ligament tear, 0.835 for lunotriquetral ligament tear, 0.799 for TFCC tear and 0.940 for chondromalacia). For the eleven cases that underwent arthroscopy, their results of 3D isovoxel MRI were also similar to that of MR arthrography. 3D isovoxel MR imaging is useful for the evaluation of the wrist joint

  19. A New Promising Technique of 3D Isovoxel Imaging Using 3T MRI in the Wrist: Comparison with 3T MR Arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Guen Young; Kim, Baek Hyun; Park, Jong Woong [Korea University Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of)

    2011-02-15

    We wanted to evaluate the usefulness of 3D isovoxel MR imaging using 3T MRI in the wrist joint, as compared with 3T MR arthrography. A total of 33 patients underwent both MR arthrography and 3D isovoxel imaging of the wrist joints using 3T MR, including 11 patients with arthroscopic confirmation. 3D isovoxel MR imaging was performed using an intermediateweighted fast spin echo coronal scan with a 0.4-mm slice thickness and the axial images were reconstructed with a 1-mm slice thickness. One radiologist evaluated for the presence of scapholunate or lunotriquetral ligament tear and she determined the grade of the triangular fibrocartilage complex tear and chondromalacia with its location. We compared the two examinations using kappa values. The rates of detecting wrist injury were similar for both exams with substantial to almost perfect inter-examination agreement (kappa value = 0.864 for scapholunate ligament tear, 0.835 for lunotriquetral ligament tear, 0.799 for TFCC tear and 0.940 for chondromalacia). For the eleven cases that underwent arthroscopy, their results of 3D isovoxel MRI were also similar to that of MR arthrography. 3D isovoxel MR imaging is useful for the evaluation of the wrist joint

  20. Soft-tissues Image Processing: Comparison of Traditional Segmentation Methods with 2D active Contour Methods

    Czech Academy of Sciences Publication Activity Database

    Mikulka, J.; Gescheidtová, E.; Bartušek, Karel

    2012-01-01

    Roč. 12, č. 4 (2012), s. 153-161 ISSN 1335-8871 R&D Projects: GA ČR GAP102/11/0318; GA ČR GAP102/12/1104; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Medical image processing * image segmentation * liver tumor * temporomandibular joint disc * watershed method Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.233, year: 2012

  1. Design of a practical model-observer-based image quality assessment method for CT imaging systems

    Science.gov (United States)

    Tseng, Hsin-Wu; Fan, Jiahua; Cao, Guangzhi; Kupinski, Matthew A.; Sainath, Paavana

    2014-03-01

    The channelized Hotelling observer (CHO) is a powerful method for quantitative image quality evaluations of CT systems and their image reconstruction algorithms. It has recently been used to validate the dose reduction capability of iterative image-reconstruction algorithms implemented on CT imaging systems. The use of the CHO for routine and frequent system evaluations is desirable both for quality assurance evaluations as well as further system optimizations. The use of channels substantially reduces the amount of data required to achieve accurate estimates of observer performance. However, the number of scans required is still large even with the use of channels. This work explores different data reduction schemes and designs a new approach that requires only a few CT scans of a phantom. For this work, the leave-one-out likelihood (LOOL) method developed by Hoffbeck and Landgrebe is studied as an efficient method of estimating the covariance matrices needed to compute CHO performance. Three different kinds of approaches are included in the study: a conventional CHO estimation technique with a large sample size, a conventional technique with fewer samples, and the new LOOL-based approach with fewer samples. The mean value and standard deviation of area under ROC curve (AUC) is estimated by shuffle method. Both simulation and real data results indicate that an 80% data reduction can be achieved without loss of accuracy. This data reduction makes the proposed approach a practical tool for routine CT system assessment.

  2. Keeping the Promise

    Science.gov (United States)

    Whissemore, Tabitha

    2016-01-01

    Since its launch in September 2015, Heads Up America has collected information on nearly 125 promise programs across the country, many of which were instituted long before President Barack Obama announced the America's College Promise (ACP) plan in 2015. At least 27 new free community college programs have launched in states, communities, and at…

  3. Adult Moyamoya disease angiographic images evolutive characters and treatment methods

    International Nuclear Information System (INIS)

    Qian Jiangnan; Ling Feng

    2000-01-01

    Objective: To discuss the angiographic images with evolutional characters and the treatment methods of the Moyamoya disease. Methods: The clinical manifestations, the radiographic changes and the comparative analysis between medicine treatment and surgery treatment, together with the laboratory tests findings were analyzed in one cases adult Moyamoya disease during six years. Conclusions: The angiographic characteristics of MMD show the supplied artery trunk stenosis, and followed by occlusion, with later appearance of vascular smoking sign. Medical treatment proved to be of null. Direct or indirect intra or extra cranial vascular anastomosis are effective for treatment

  4. Apparatus and method for motion tracking in brain imaging

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is apparatus and method for motion tracking of a subject in medical brain imaging. The method comprises providing a light projector and a first camera; projecting a first pattern sequence (S1) onto a surface region of the subject with the light projector, wherein the subject is positioned......2,1) based on the detected first pattern sequence (S1'); projecting the second pattern sequence (S2) onto a surface region of the subject with the light projector; detecting the projected second pattern sequence (S2') with the first camera; and determining motion tracking parameters based...

  5. Methods for modeling and quantification in functional imaging by positron emissions tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Costes, Nicolas

    2017-01-01

    This report presents experiences and researches in the field of in vivo medical imaging by positron emission tomography (PET) and magnetic resonance imaging (MRI). In particular, advances in terms of reconstruction, quantification and modeling in PET are described. The validation of processing and analysis methods is supported by the creation of data by simulation of the imaging process in PET. The recent advances of combined PET/MRI clinical cameras, allowing simultaneous acquisition of molecular/metabolic PET information, and functional/structural MRI information opens the door to unique methodological innovations, exploiting spatial alignment and simultaneity of the PET and MRI signals. It will lead to an increase in accuracy and sensitivity in the measurement of biological phenomena. In this context, the developed projects address new methodological issues related to quantification, and to the respective contributions of MRI or PET information for a reciprocal improvement of the signals of the two modalities. They open perspectives for combined analysis of the two imaging techniques, allowing optimal use of synchronous, anatomical, molecular and functional information for brain imaging. These innovative concepts, as well as data correction and analysis methods, will be easily translated into other areas of investigation using combined PET/MRI. (author) [fr

  6. Does thorax EIT image analysis depend on the image reconstruction method?

    Science.gov (United States)

    Zhao, Zhanqi; Frerichs, Inéz; Pulletz, Sven; Müller-Lisse, Ullrich; Möller, Knut

    2013-04-01

    Different methods were proposed to analyze the resulting images of electrical impedance tomography (EIT) measurements during ventilation. The aim of our study was to examine if the analysis methods based on back-projection deliver the same results when applied on images based on other reconstruction algorithms. Seven mechanically ventilated patients with ARDS were examined by EIT. The thorax contours were determined from the routine CT images. EIT raw data was reconstructed offline with (1) filtered back-projection with circular forward model (BPC); (2) GREIT reconstruction method with circular forward model (GREITC) and (3) GREIT with individual thorax geometry (GREITT). Three parameters were calculated on the resulting images: linearity, global ventilation distribution and regional ventilation distribution. The results of linearity test are 5.03±2.45, 4.66±2.25 and 5.32±2.30 for BPC, GREITC and GREITT, respectively (median ±interquartile range). The differences among the three methods are not significant (p = 0.93, Kruskal-Wallis test). The proportions of ventilation in the right lung are 0.58±0.17, 0.59±0.20 and 0.59±0.25 for BPC, GREITC and GREITT, respectively (p = 0.98). The differences of the GI index based on different reconstruction methods (0.53±0.16, 0.51±0.25 and 0.54±0.16 for BPC, GREITC and GREITT, respectively) are also not significant (p = 0.93). We conclude that the parameters developed for images generated with GREITT are comparable with filtered back-projection and GREITC.

  7. The Z-isomer of 11 beta-methoxy-17 alpha-[123I]iodovinylestradiol is a promising radioligand for estrogen receptor imaging in human breast cancer

    NARCIS (Netherlands)

    Rijks, L. J.; Boer, G. J.; Endert, E.; de Bruin, K.; Janssen, A. G.; van Royen, E. A.

    1997-01-01

    The potential of both stereoisomers of 11 beta-methoxy-17 alpha-[123I] iodovinylestradiol (E- and Z-[123I]MIVE) as suitable radioligands for imaging of estrogen receptor (ER)-positive human breast tumours was studied. The 17 alpha-[123I]iodovinylestradiol derivatives were prepared stereospecifically

  8. High-resolution imaging methods in array signal processing

    DEFF Research Database (Denmark)

    Xenaki, Angeliki

    in active sonar signal processing for detection and imaging of submerged oil contamination in sea water from a deep-water oil leak. The submerged oil _eld is modeled as a uid medium exhibiting spatial perturbations in the acoustic parameters from their mean ambient values which cause weak scattering...... of the incident acoustic energy. A highfrequency active sonar is selected to insonify the medium and receive the backscattered waves. High-frequency acoustic methods can both overcome the optical opacity of water (unlike methods based on electromagnetic waves) and resolve the small-scale structure...... of the submerged oil field (unlike low-frequency acoustic methods). The study shows that high-frequency acoustic methods are suitable not only for large-scale localization of the oil contamination in the water column but also for statistical characterization of the submerged oil field through inference...

  9. Image processing methods and architectures in diagnostic pathology.

    Directory of Open Access Journals (Sweden)

    Oscar DĂŠniz

    2010-05-01

    Full Text Available Grid technology has enabled the clustering and the efficient and secure access to and interaction among a wide variety of geographically distributed resources such as: supercomputers, storage systems, data sources, instruments and special devices and services. Their main applications include large-scale computational and data intensive problems in science and engineering. General grid structures and methodologies for both software and hardware in image analysis for virtual tissue-based diagnosis has been considered in this paper. This methods are focus on the user level middleware. The article describes the distributed programming system developed by the authors for virtual slide analysis in diagnostic pathology. The system supports different image analysis operations commonly done in anatomical pathology and it takes into account secured aspects and specialized infrastructures with high level services designed to meet application requirements. Grids are likely to have a deep impact on health related applications, and therefore they seem to be suitable for tissue-based diagnosis too. The implemented system is a joint application that mixes both Web and Grid Service Architecture around a distributed architecture for image processing. It has shown to be a successful solution to analyze a big and heterogeneous group of histological images under architecture of massively parallel processors using message passing and non-shared memory.

  10. Color management systems: methods and technologies for increased image quality

    Science.gov (United States)

    Caretti, Maria

    1997-02-01

    All the steps in the imaging chain -- from handling the originals in the prepress to outputting them on any device - - have to be well calibrated and adjusted to each other, in order to reproduce color images in a desktop environment as accurate as possible according to the original. Today most of the steps in the prepress production are digital and therefore it is realistic to believe that the color reproduction can be well controlled. This is true thanks to the last years development of fast, cost effective scanners, digital sources and digital proofing devices not the least. It is likely to believe that well defined tools and methods to control this imaging flow will lead to large cost and time savings as well as increased overall image quality. Until now, there has been a lack of good, reliable, easy-to- use systems (e.g. hardware, software, documentation, training and support) in an extent that has made them accessible to the large group of users of graphic arts production systems. This paper provides an overview of the existing solutions to manage colors in a digital pre-press environment. Their benefits and limitations are discussed as well as how they affect the production workflow and organization. The difference between a color controlled environment and one that is not is explained.

  11. Information theoretic methods for image processing algorithm optimization

    Science.gov (United States)

    Prokushkin, Sergey F.; Galil, Erez

    2015-01-01

    Modern image processing pipelines (e.g., those used in digital cameras) are full of advanced, highly adaptive filters that often have a large number of tunable parameters (sometimes > 100). This makes the calibration procedure for these filters very complex, and the optimal results barely achievable in the manual calibration; thus an automated approach is a must. We will discuss an information theory based metric for evaluation of algorithm adaptive characteristics ("adaptivity criterion") using noise reduction algorithms as an example. The method allows finding an "orthogonal decomposition" of the filter parameter space into the "filter adaptivity" and "filter strength" directions. This metric can be used as a cost function in automatic filter optimization. Since it is a measure of a physical "information restoration" rather than perceived image quality, it helps to reduce the set of the filter parameters to a smaller subset that is easier for a human operator to tune and achieve a better subjective image quality. With appropriate adjustments, the criterion can be used for assessment of the whole imaging system (sensor plus post-processing).

  12. Statistical methods of evaluating and comparing imaging techniques

    International Nuclear Information System (INIS)

    Freedman, L.S.

    1987-01-01

    Over the past 20 years several new methods of generating images of internal organs and the anatomy of the body have been developed and used to enhance the accuracy of diagnosis and treatment. These include ultrasonic scanning, radioisotope scanning, computerised X-ray tomography (CT) and magnetic resonance imaging (MRI). The new techniques have made a considerable impact on radiological practice in hospital departments, not least on the investigational process for patients suspected or known to have malignant disease. As a consequence of the increased range of imaging techniques now available, there has developed a need to evaluate and compare their usefulness. Over the past 10 years formal studies of the application of imaging technology have been conducted and many reports have appeared in the literature. These studies cover a range of clinical situations. Likewise, the methodologies employed for evaluating and comparing the techniques in question have differed widely. While not attempting an exhaustive review of the clinical studies which have been reported, this paper aims to examine the statistical designs and analyses which have been used. First a brief review of the different types of study is given. Examples of each type are then chosen to illustrate statistical issues related to their design and analysis. In the final sections it is argued that a form of classification for these different types of study might be helpful in clarifying relationships between them and bringing a perspective to the field. A classification based upon a limited analogy with clinical trials is suggested

  13. A Method for Determining Skeletal Lengths from DXA Images

    Directory of Open Access Journals (Sweden)

    Fogelman Ignac

    2007-11-01

    Full Text Available Abstract Background Skeletal ratios and bone lengths are widely used in anthropology and forensic pathology and hip axis length is a useful predictor of fracture. The aim of this study was to show that skeletal ratios, such as length of femur to height, could be accurately measured from a DXA (dual energy X-ray absorptiometry image. Methods 90 normal Caucasian females, 18–80 years old, with whole body DXA data were used as subjects. Two methods, linear pixel count (LPC and reticule and ruler (RET were used to measure skeletal sizes on DXA images and compared with real clinical measures from 20 subjects and 20 x-rays of the femur and tibia taken in 2003. Results Although both methods were highly correlated, the LPC inter- and intra-observer error was lower at 1.6% compared to that of RET at 2.3%. Both methods correlated positively with real clinical measures, with LPC having a marginally stronger correlation coefficient (r2 = 0.94; r2 = 0.84; average r2 = 0.89 than RET (r2 = 0.86; r2 = 0.84; average r2 = 0.85 with X-rays and real measures respectively. Also, the time taken to use LPC was half that of RET at 5 minutes per scan. Conclusion Skeletal ratios can be accurately and precisely measured from DXA total body scan images. The LPC method is easy to use and relatively rapid. This new phenotype will be useful for osteoporosis research for individuals or large-scale epidemiological or genetic studies.

  14. Speech system of the brain: Insight via functional imaging methods

    Directory of Open Access Journals (Sweden)

    Kristjan Sancin

    2004-08-01

    Full Text Available The study of neural correlates of language has always lagged behind the study of other aspects of behavior and cognition due to the lack of an animal model. Clinical data led to the idea that language perception is localized in the posterior superior temporal lobe (Wernicke's area and functions related to speech production are localized in the lateral frontal lobe (Broca's area of the dominant hemisphere. Recent data from electrophysiological and functional neuroimaging investigations shows that the roles of Wernicke's and Broca's areas are not as clear as they appeared. A variety of cortical and subcortical regions have been found to be critically important for language processing. Functional magnetic resonance imaging (fMRI can be used to study language system of the brain. When planning certain neurosurgical interventions, it is important to determine hemispheric language dominance and localization of language functions in order to avoid damaging these areas. Some fMRI language paradigms promise a completely noninvasive way of localizing language functions in an individual patient – a possible substitute for the tests currently in use. In our lab, we have recently started to use fMRI for localization of cortical language areas in healthy individuals and in neurological patients.

  15. Internal scanning method as unique imaging method of optical vortex scanning microscope

    Science.gov (United States)

    Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

    2018-06-01

    The internal scanning method is specific for the optical vortex microscope. It allows to move the vortex point inside the focused vortex beam with nanometer resolution while the whole beam stays in place. Thus the sample illuminated by the focused vortex beam can be scanned just by the vortex point. We show that this method enables high resolution imaging. The paper presents the preliminary experimental results obtained with the first basic image recovery procedure. A prospect of developing more powerful tools for topography recovery with the optical vortex scanning microscope is discussed shortly.

  16. Simultaneous collection method of on-peak window image and off-peak window image in Tl-201 imaging

    International Nuclear Information System (INIS)

    Murakami, Tomonori; Noguchi, Yasushi; Kojima, Akihiro; Takagi, Akihiro; Matsumoto, Masanori

    2007-01-01

    Tl-201 imaging detects the photopeak (71 keV, in on-peak window) of characteristic X-rays of Hg-201 formed from Tl-201 decay. The peak is derived from 4 rays of different energy and emission intensity and does not follow in Gaussian distribution. In the present study, authors made an idea for the method in the title to attain the more effective single imaging, which was examined for its accuracy and reliability with phantoms and applied clinically to Tl-201 scintigraphy in a patient. The authors applied the triple energy window method for data acquisition: the energy window setting was made on Hg-201 X-rays photopeak in three of the lower (3%, L), main (72 keV, M) and upper (14%, U) windows with the gamma camera with 2-gated detector (Toshiba E. CAM/ICON). L, M and U images obtained simultaneously were then constructed to images of on-peak (L+M, Mock on-peak) and off-peak (M+U) window settings for evaluation. Phantoms for line source with Tl-201-containing swab and for multi-defect with acrylic plate containing Tl-201 solution were imaged in water. The female patient with thyroid cancer was subjected to preoperative scintigraphy under the defined conditions. Mock on-, off-peak images were found to be equivalent to the true (ordinary, clinical) on-, off-peak ones, and the present method was thought usable for evaluation of usefulness of off-peak window data. (R.T.)

  17. Image reconstruction in computerized tomography using the convolution method

    International Nuclear Information System (INIS)

    Oliveira Rebelo, A.M. de.

    1984-03-01

    In the present work an algoritin was derived, using the analytical convolution method (filtered back-projection) for two-dimensional or three-dimensional image reconstruction in computerized tomography applied to non-destructive testing and to the medical use. This mathematical model is based on the analytical Fourier transform method for image reconstruction. This model consists of a discontinuous system formed by an NxN array of cells (pixels). The attenuation in the object under study of a colimated gamma ray beam has been determined for various positions and incidence angles (projections) in terms of the interaction of the beam with the intercepted pixels. The contribution of each pixel to beam attenuation was determined using the weight function W ij which was used for simulated tests. Simulated tests using standard objects with attenuation coefficients in the range of 0,2 to 0,7 cm -1 were carried out using cell arrays of up to 25x25. One application was carried out in the medical area simulating image reconstruction of an arm phantom with attenuation coefficients in the range of 0,2 to 0,5 cm -1 using cell arrays of 41x41. The simulated results show that, in objects with a great number of interfaces and great variations of attenuation coefficients at these interfaces, a good reconstruction is obtained with the number of projections equal to the reconstruction matrix dimension. A good reconstruction is otherwise obtained with fewer projections. (author) [pt

  18. Image reconstruction methods for the PBX-M pinhole camera

    International Nuclear Information System (INIS)

    Holland, A.; Powell, E.T.; Fonck, R.J.

    1990-03-01

    This paper describes two methods which have been used to reconstruct the soft x-ray emission profile of the PBX-M tokamak from the projected images recorded by the PBX-M pinhole camera. Both methods must accurately represent the shape of the reconstructed profile while also providing a degree of immunity to noise in the data. The first method is a simple least squares fit to the data. This has the advantage of being fast and small, and thus easily implemented on the PDP-11 computer used to control the video digitizer for the pinhole camera. The second method involves the application of a maximum entropy algorithm to an overdetermined system. This has the advantage of allowing the use of a default profile. This profile contains additional knowledge about the plasma shape which can be obtained from equilibrium fits to the external magnetic measurements. Additionally the reconstruction is guaranteed positive, and the fit to the data can be relaxed by specifying both the amount and distribution of noise in the image. The algorithm described has the advantage of being considerably faster, for an overdetermined system, than the usual Lagrange multiplier approach to finding the maximum entropy solution. 13 refs., 24 figs

  19. Fringe image analysis based on the amplitude modulation method.

    Science.gov (United States)

    Gai, Shaoyan; Da, Feipeng

    2010-05-10

    A novel phase-analysis method is proposed. To get the fringe order of a fringe image, the amplitude-modulation fringe pattern is carried out, which is combined with the phase-shift method. The primary phase value is obtained by a phase-shift algorithm, and the fringe-order information is encoded in the amplitude-modulation fringe pattern. Different from other methods, the amplitude-modulation fringe identifies the fringe order by the amplitude of the fringe pattern. In an amplitude-modulation fringe pattern, each fringe has its own amplitude; thus, the order information is integrated in one fringe pattern, and the absolute fringe phase can be calculated correctly and quickly with the amplitude-modulation fringe image. The detailed algorithm is given, and the error analysis of this method is also discussed. Experimental results are presented by a full-field shape measurement system where the data has been processed using the proposed algorithm. (c) 2010 Optical Society of America.

  20. Determining wood chip size: image analysis and clustering methods

    Directory of Open Access Journals (Sweden)

    Paolo Febbi

    2013-09-01

    Full Text Available One of the standard methods for the determination of the size distribution of wood chips is the oscillating screen method (EN 15149- 1:2010. Recent literature demonstrated how image analysis could return highly accurate measure of the dimensions defined for each individual particle, and could promote a new method depending on the geometrical shape to determine the chip size in a more accurate way. A sample of wood chips (8 litres was sieved through horizontally oscillating sieves, using five different screen hole diameters (3.15, 8, 16, 45, 63 mm; the wood chips were sorted in decreasing size classes and the mass of all fractions was used to determine the size distribution of the particles. Since the chip shape and size influence the sieving results, Wang’s theory, which concerns the geometric forms, was considered. A cluster analysis on the shape descriptors (Fourier descriptors and size descriptors (area, perimeter, Feret diameters, eccentricity was applied to observe the chips distribution. The UPGMA algorithm was applied on Euclidean distance. The obtained dendrogram shows a group separation according with the original three sieving fractions. A comparison has been made between the traditional sieve and clustering results. This preliminary result shows how the image analysis-based method has a high potential for the characterization of wood chip size distribution and could be further investigated. Moreover, this method could be implemented in an online detection machine for chips size characterization. An improvement of the results is expected by using supervised multivariate methods that utilize known class memberships. The main objective of the future activities will be to shift the analysis from a 2-dimensional method to a 3- dimensional acquisition process.

  1. Methods and applications in high flux neutron imaging

    International Nuclear Information System (INIS)

    Ballhausen, H.

    2007-01-01

    This treatise develops new methods for high flux neutron radiography and high flux neutron tomography and describes some of their applications in actual experiments. Instead of single images, time series can be acquired with short exposure times due to the available high intensity. To best use the increased amount of information, new estimators are proposed, which extract accurate results from the recorded ensembles, even if the individual piece of data is very noisy and in addition severely affected by systematic errors such as an influence of gamma background radiation. The spatial resolution of neutron radiographies, usually limited by beam divergence and inherent resolution of the scintillator, can be significantly increased by scanning the sample with a pinhole-micro-collimator. This technique circumvents any limitations in present detector design and, due to the available high intensity, could be successfully tested. Imaging with scattered neutrons as opposed to conventional total attenuation based imaging determines separately the absorption and scattering cross sections within the sample. For the first time even coherent angle dependent scattering could be visualized space-resolved. New applications of high flux neutron imaging are presented, such as materials engineering experiments on innovative metal joints, time-resolved tomography on multilayer stacks of fuel cells under operation, and others. A new implementation of an algorithm for the algebraic reconstruction of tomography data executes even in case of missing information, such as limited angle tomography, and returns quantitative reconstructions. The setup of the world-leading high flux radiography and tomography facility at the Institut Laue-Langevin is presented. A comprehensive appendix covers the physical and technical foundations of neutron imaging. (orig.)

  2. Error of image saturation in the structured-light method.

    Science.gov (United States)

    Qi, Zhaoshuai; Wang, Zhao; Huang, Junhui; Xing, Chao; Gao, Jianmin

    2018-01-01

    In the phase-measuring structured-light method, image saturation will induce large phase errors. Usually, by selecting proper system parameters (such as the phase-shift number, exposure time, projection intensity, etc.), the phase error can be reduced. However, due to lack of a complete theory of phase error, there is no rational principle or basis for the selection of the optimal system parameters. For this reason, the phase error due to image saturation is analyzed completely, and the effects of the two main factors, including the phase-shift number and saturation degree, on the phase error are studied in depth. In addition, the selection of optimal system parameters is discussed, including the proper range and the selection principle of the system parameters. The error analysis and the conclusion are verified by simulation and experiment results, and the conclusion can be used for optimal parameter selection in practice.

  3. DAFS measurements using the image-plate Weissenberg method

    International Nuclear Information System (INIS)

    Sugioka, N.; Matsumoto, K.; Sasaki, S.; Tanaka, M.; Mori, T.

    1998-01-01

    An instrumental technique for DAFS measurements which can provide site-specific information is proposed. The approach uses (i) focusing optics with parabolic mirrors and a double-crystal monochromator, (ii) the Laue and Bragg settings and (iii) data collection by the image-plate Weissenberg method. Six image exposures are recorded per plate at five intrinsic energies and one reference energy. The single-crystal measurements were performed at the Co K-absorption edge, and the 200, 220 and 311 reflections of CoO and 511 and 911 reflections of Co 3 O 4 were used for analysis. The regression analysis of χ(k), Fourier transforms of k 3 χ(k) and back-Fourier filtering have been performed

  4. Expanded image database of pistachio x-ray images and classification by conventional methods

    Science.gov (United States)

    Keagy, Pamela M.; Schatzki, Thomas F.; Le, Lan Chau; Casasent, David P.; Weber, David

    1996-12-01

    In order to develop sorting methods for insect damaged pistachio nuts, a large data set of pistachio x-ray images (6,759 nuts) was created. Both film and linescan sensor images were acquired, nuts dissected and internal conditions coded using the U.S. Grade standards and definitions for pistachios. A subset of 1199 good and 686 insect damaged nuts was used to calculate and test discriminant functions. Statistical parameters of image histograms were evaluated for inclusion by forward stepwise discrimination. Using three variables in the discriminant function, 89% of test set nuts were correctly identified. Comparable data for 6 human subjects ranged from 67 to 92%. If the loss of good nuts is held to 1% by requiring a high probability to discard a nut as insect damaged, approximately half of the insect damage present in clean pistachio nuts may be detected and removed by x-ray inspection.

  5. General filtering method for electronic speckle pattern interferometry fringe images with various densities based on variational image decomposition.

    Science.gov (United States)

    Li, Biyuan; Tang, Chen; Gao, Guannan; Chen, Mingming; Tang, Shuwei; Lei, Zhenkun

    2017-06-01

    Filtering off speckle noise from a fringe image is one of the key tasks in electronic speckle pattern interferometry (ESPI). In general, ESPI fringe images can be divided into three categories: low-density fringe images, high-density fringe images, and variable-density fringe images. In this paper, we first present a general filtering method based on variational image decomposition that can filter speckle noise for ESPI fringe images with various densities. In our method, a variable-density ESPI fringe image is decomposed into low-density fringes, high-density fringes, and noise. A low-density fringe image is decomposed into low-density fringes and noise. A high-density fringe image is decomposed into high-density fringes and noise. We give some suitable function spaces to describe low-density fringes, high-density fringes, and noise, respectively. Then we construct several models and numerical algorithms for ESPI fringe images with various densities. And we investigate the performance of these models via our extensive experiments. Finally, we compare our proposed models with the windowed Fourier transform method and coherence enhancing diffusion partial differential equation filter. These two methods may be the most effective filtering methods at present. Furthermore, we use the proposed method to filter a collection of the experimentally obtained ESPI fringe images with poor quality. The experimental results demonstrate the performance of our proposed method.

  6. Early Detection of Diabetic Retinopathy in Fluorescent Angiography Retinal Images Using Image Processing Methods

    Directory of Open Access Journals (Sweden)

    Meysam Tavakoli

    2010-12-01

    Full Text Available Introduction: Diabetic retinopathy (DR is the single largest cause of sight loss and blindness in the working age population of Western countries; it is the most common cause of blindness in adults between 20 and 60 years of age. Early diagnosis of DR is critical for preventing vision loss so early detection of microaneurysms (MAs as the first signs of DR is important. This paper addresses the automatic detection of MAs in fluorescein angiography fundus images, which plays a key role in computer assisted diagnosis of DR, a serious and frequent eye disease. Material and Methods: The algorithm can be divided into three main steps. The first step or pre-processing was for background normalization and contrast enhancement of the image. The second step aimed at detecting landmarks, i.e., all patterns possibly corresponding to vessels and the optic nerve head, which was achieved using a local radon transform. Then, MAs were extracted, which were used in the final step to automatically classify candidates into real MA and other objects. A database of 120 fluorescein angiography fundus images was used to train and test the algorithm. The algorithm was compared to manually obtained gradings of those images. Results: Sensitivity of diagnosis for DR was 94%, with specificity of 75%, and sensitivity of precise microaneurysm localization was 92%, at an average number of 8 false positives per image. Discussion and Conclusion: Sensitivity and specificity of this algorithm make it one of the best methods in this field. Using local radon transform in this algorithm eliminates the noise sensitivity for microaneurysm detection in retinal image analysis.

  7. Promise Zones for Applicants

    Data.gov (United States)

    Department of Housing and Urban Development — This tool assists applicants to HUD's Promise Zone initiative prepare data to submit with their application by allowing applicants to draw the exact location of the...

  8. Definition imaging of an orebody with the radio imaging method (RIM)

    International Nuclear Information System (INIS)

    Stolarczyk, L.G.

    1992-01-01

    Waste rock dilution is an economic concern in the planning and design of mining methods for mineralized ore zones. Diamond core drilling and mineralogical examination of core are routinely used to determine the general shape of the ore body. Drilling on closer centers enhances the definition of the mineralization and oregrade across the orebody. In a practical sense, drilling time and cost limit definition. Crosshole scanning between drillholes with the radio imaging method (RIM) has been used to map changes in mineralization in the rock mass. The magnitude and phase of the RIM radio wave depend on the electrical conductivity of the rock mass. The conductivity strongly depends on the percent mineralization. Since the attenuation rate and phase constants of the radio wave are proportional to the one half power of conductivity, the measured crosshole radio wave data can be processed in a tomography algorithm to reconstruct images (map the change in conductivity (mineralization)). The tomography image enhances definition in the orebody while reducing the number of drillholes. This paper compares reconstructed images of the radio wave propagation constants to percent mineralization in the ore body

  9. Haemodynamic imaging of thoracic stent-grafts by computational fluid dynamics (CFD): presentation of a patient-specific method combining magnetic resonance imaging and numerical simulations.

    Science.gov (United States)

    Midulla, Marco; Moreno, Ramiro; Baali, Adil; Chau, Ming; Negre-Salvayre, Anne; Nicoud, Franck; Pruvo, Jean-Pierre; Haulon, Stephan; Rousseau, Hervé

    2012-10-01

    In the last decade, there was been increasing interest in finding imaging techniques able to provide a functional vascular imaging of the thoracic aorta. The purpose of this paper is to present an imaging method combining magnetic resonance imaging (MRI) and computational fluid dynamics (CFD) to obtain a patient-specific haemodynamic analysis of patients treated by thoracic endovascular aortic repair (TEVAR). MRI was used to obtain boundary conditions. MR angiography (MRA) was followed by cardiac-gated cine sequences which covered the whole thoracic aorta. Phase contrast imaging provided the inlet and outlet profiles. A CFD mesh generator was used to model the arterial morphology, and wall movements were imposed according to the cine imaging. CFD runs were processed using the finite volume (FV) method assuming blood as a homogeneous Newtonian fluid. Twenty patients (14 men; mean age 62.2 years) with different aortic lesions were evaluated. Four-dimensional mapping of velocity and wall shear stress were obtained, depicting different patterns of flow (laminar, turbulent, stenosis-like) and local alterations of parietal stress in-stent and along the native aorta. A computational method using a combined approach with MRI appears feasible and seems promising to provide detailed functional analysis of thoracic aorta after stent-graft implantation. • Functional vascular imaging of the thoracic aorta offers new diagnostic opportunities • CFD can model vascular haemodynamics for clinical aortic problems • Combining CFD with MRI offers patient specific method of aortic analysis • Haemodynamic analysis of stent-grafts could improve clinical management and follow-up.

  10. An Optimized Method for Terrain Reconstruction Based on Descent Images

    Directory of Open Access Journals (Sweden)

    Xu Xinchao

    2016-02-01

    Full Text Available An optimization method is proposed to perform high-accuracy terrain reconstruction of the landing area of Chang’e III. First, feature matching is conducted using geometric model constraints. Then, the initial terrain is obtained and the initial normal vector of each point is solved on the basis of the initial terrain. By changing the vector around the initial normal vector in small steps a set of new vectors is obtained. By combining these vectors with the direction of light and camera, the functions are set up on the basis of a surface reflection model. Then, a series of gray values is derived by solving the equations. The new optimized vector is recorded when the obtained gray value is closest to the corresponding pixel. Finally, the optimized terrain is obtained after iteration of the vector field. Experiments were conducted using the laboratory images and descent images of Chang’e III. The results showed that the performance of the proposed method was better than that of the classical feature matching method. It can provide a reference for terrain reconstruction of the landing area in subsequent moon exploration missions.

  11. Various imaging methods in the detection of small hepatomas

    International Nuclear Information System (INIS)

    Nakatsuka, Haruki; Kaminou, Toshio; Takemoto, Kazumasa; Takashima, Sumio; Kobayashi, Nobuyuki; Nakamura, Kenji; Onoyama, Yasuto; Kurioka, Naruto

    1985-01-01

    Fifty-one patients with small hepatomas under 5 cm in diameter were studied to compare the detectability of various imaging methods. Positive finding was obtained in 50 % of the patients by scintigraphy, in 74 % by ultrasonography and in 79 % by CT during screening tests. Rate of detection in retrospective analysis, after the site of the tumor had been known, were 73 %, 93 % and 87 % respectively. Rate of detection was 92 % by celiac arteriography and 98 % by selective hepatic arteriography. In 21 patients, who had the tumor under 3 cm, the rate was 32 % for scintigraphy, 74 % for ultrasonography and 65 % for CT during screening, whereas it was 58 %, 84 % and 75 % retrospectively. By celiac arteriography, it was 85 %, and by hepatic arteriography, 95 %. Rate of detection of small hepatomas in screening tests differed remarkably from that in retrospective analysis. No single method of imaging can disclose reliably the presense of small hepatoma, therefore more than one method should be used in screening. (author)

  12. Parallel MR image reconstruction using augmented Lagrangian methods.

    Science.gov (United States)

    Ramani, Sathish; Fessler, Jeffrey A

    2011-03-01

    Magnetic resonance image (MRI) reconstruction using SENSitivity Encoding (SENSE) requires regularization to suppress noise and aliasing effects. Edge-preserving and sparsity-based regularization criteria can improve image quality, but they demand computation-intensive nonlinear optimization. In this paper, we present novel methods for regularized MRI reconstruction from undersampled sensitivity encoded data--SENSE-reconstruction--using the augmented Lagrangian (AL) framework for solving large-scale constrained optimization problems. We first formulate regularized SENSE-reconstruction as an unconstrained optimization task and then convert it to a set of (equivalent) constrained problems using variable splitting. We then attack these constrained versions in an AL framework using an alternating minimization method, leading to algorithms that can be implemented easily. The proposed methods are applicable to a general class of regularizers that includes popular edge-preserving (e.g., total-variation) and sparsity-promoting (e.g., l(1)-norm of wavelet coefficients) criteria and combinations thereof. Numerical experiments with synthetic and in vivo human data illustrate that the proposed AL algorithms converge faster than both general-purpose optimization algorithms such as nonlinear conjugate gradient (NCG) and state-of-the-art MFISTA.

  13. Variational Level Set Method for Two-Stage Image Segmentation Based on Morphological Gradients

    Directory of Open Access Journals (Sweden)

    Zemin Ren

    2014-01-01

    Full Text Available We use variational level set method and transition region extraction techniques to achieve image segmentation task. The proposed scheme is done by two steps. We first develop a novel algorithm to extract transition region based on the morphological gradient. After this, we integrate the transition region into a variational level set framework and develop a novel geometric active contour model, which include an external energy based on transition region and fractional order edge indicator function. The external energy is used to drive the zero level set toward the desired image features, such as object boundaries. Due to this external energy, the proposed model allows for more flexible initialization. The fractional order edge indicator function is incorporated into the length regularization term to diminish the influence of noise. Moreover, internal energy is added into the proposed model to penalize the deviation of the level set function from a signed distance function. The results evolution of the level set function is the gradient flow that minimizes the overall energy functional. The proposed model has been applied to both synthetic and real images with promising results.

  14. Imaging method of minute injured area at achilles tendon from multiple MR Images

    International Nuclear Information System (INIS)

    Tokui, Takahiro; Imura, Masataka; Kuroda, Yoshihiro; Oshiro, Osamu; Oguchi, Makoto; Fujiwara, Kazuhisa; Tabata, Yoshito; Ishigaki, Rikuta

    2011-01-01

    Ruptures of Achilles tendon frequently occur while doing sports. Since two-thirds of the people who suffered from the rupture of Achilles tendon feel the pain at Achilles tendon before rupture, to detect the predictor of the rupture is possible. Achilles tendon is soft tissue consisting of unidirectionally-aligned collagen fibers. Therefore, ordinary MRI scanner, ultrasonic instrument or X-ray scanner cannot acquire medical images of Achilles tendon. However, because MR signal intensity changes according to the angle between static magnetic field direction and fiber orientation, MR device can detect strong signal when the angle is 55 deg. In this research, the authors propose the imaging method to detect injured area at Achilles tendon. The method calculates and visualizes the value representing fiber tropism from the matching between MR signal intensity and the model of signal intensity of angle dependence. (author)

  15. Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods.

    Science.gov (United States)

    Barbosa, José Augusto A; Rodrigues, Alexandre B; Mota, Cleonice Carvalho C; Barbosa, Márcia M; Simões e Silva, Ana C

    2011-01-01

    Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.

  16. Autofluorescence imaging can identify preinvasive or clinically occult lesions in fallopian tube epithelium: a promising step towards screening and early detection.

    Science.gov (United States)

    McAlpine, J N; El Hallani, S; Lam, S F; Kalloger, S E; Luk, M; Huntsman, D G; MacAulay, C; Gilks, C B; Miller, D M; Lane, P M

    2011-03-01

    Optical imaging systems are robust, portable, relatively inexpensive, and have proven utility in detecting precancerous lesions in the lung, esophagus, colon, oral cavity and cervix. We describe the use of light-induced endogenous fluorescence (autofluorescence) in identifying preinvasive and occult carcinomas in ex vivo samples of human fallopian tube (FT) epithelium. Women undergoing surgery for an i) ovarian mass, ii) a history suggestive of hereditary breast-ovarian cancer, or iii) known serous ovarian cancer following neoadjuvant chemotherapy (NAC) were approached for informed consent. Immediately following surgery, FT's were photographed in reflectance and fluorescence at high resolution. Images included: (1) white-light reflectance of luminal/epithelial surface; (2) narrow-band green reflectance (570 nm) (3) green autofluorescence (405/436 nm excitation); and (4) blue autofluorescence (405 nm excitation). Areas revealing a loss of natural tissue fluorescence or marked increase in tissue microvasculature were recorded and compared to final histopathologic diagnosis (SEE-FIM protocol). Fifty-six cases involving one or both fallopian tubes underwent reflectance and fluorescence visualization. Nine cases were excluded, either secondary to non-ovarian primary pathology (7) or excessive trauma (2) rendering tissue interpretation impossible. Of the 47 cases remaining, there were 11 high grade serous (HGS) and 9 non-serous ovarian carcinomas undergoing primary debulking surgery, 5 serous carcinomas having received NAC, 8 benign ovarian tumors, and 14 women undergoing risk-reducing bilateral salpingo-oophorectomy (RRBSO). Methodology was feasible, efficient, and reproducible. TIC or carcinoma was identified in 7/11 HGS, 3/5 NAC, and 1/14 RRBSO. Optical images were reviewed to determine test positive or negative based on standardized criteria. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for the entire

  17. On the convergence of nonconvex minimization methods for image recovery.

    Science.gov (United States)

    Xiao, Jin; Ng, Michael Kwok-Po; Yang, Yu-Fei

    2015-05-01

    Nonconvex nonsmooth regularization method has been shown to be effective for restoring images with neat edges. Fast alternating minimization schemes have also been proposed and developed to solve the nonconvex nonsmooth minimization problem. The main contribution of this paper is to show the convergence of these alternating minimization schemes, based on the Kurdyka-Łojasiewicz property. In particular, we show that the iterates generated by the alternating minimization scheme, converges to a critical point of this nonconvex nonsmooth objective function. We also extend the analysis to nonconvex nonsmooth regularization model with box constraints, and obtain similar convergence results of the related minimization algorithm. Numerical examples are given to illustrate our convergence analysis.

  18. Image Signal Transfer Method in Artificial Retina using Laser

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, I.Y.; Lee, B.H.; Kim, S.J. [Seoul National University, Seoul (Korea)

    2002-05-01

    Recently, the research on artificial retina for the blind is active. In this paper a new optical link method for the retinal prosthesis is proposed. Laser diode system was chosen to transfer image into the eye in this project and the new optical system was designed and evaluated. The use of laser diode array in artificial retina system makes system simple for lack of signal processing part inside of the eyeball. Designed optical system is enough to focus laser diode array on photodiode array in 20X20 application. (author). 11 refs., 7 figs., 2 tabs.

  19. Application of image processing methods to industrial radiography

    International Nuclear Information System (INIS)

    Goutte, R.; Odet, C.; Tuncer, T.; Bodson, F.; Varcin, E.

    1985-01-01

    This study was carried out with the financial support of the Commission of the European Communities as part of the CECA research program comprising of IRSID, INSA de Lyon and the Framatome and Creusot Loire companies. Its purpose was to evaluate the possibility of using digital enhancement of radiographic images to improve defect visibility in industrial radiography, thereby providing assistance in defect detection and a method for automatic analysis of radiographs. This paper provides full results obtained from work on digital processing of radiographs showing real and artificial defects. Furthermore, work on simulated automatic defect detection is also presented. 2 refs

  20. Research on Methods of Infrared and Color Image Fusion Based on Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Zhao Rentao

    2014-06-01

    Full Text Available There is significant difference in the imaging features of infrared image and color image, but their fusion images also have very good complementary information. In this paper, based on the characteristics of infrared image and color image, first of all, wavelet transform is applied to the luminance component of the infrared image and color image. In multi resolution the relevant regional variance is regarded as the activity measure, relevant regional variance ratio as the matching measure, and the fusion image is enhanced in the process of integration, thus getting the fused images by final synthesis module and multi-resolution inverse transform. The experimental results show that the fusion image obtained by the method proposed in this paper is better than the other methods in keeping the useful information of the original infrared image and the color information of the original color image. In addition, the fusion image has stronger adaptability and better visual effect.

  1. Method to acquire regions of fruit, branch and leaf from image of red apple in orchard

    Science.gov (United States)

    Lv, Jidong; Xu, Liming

    2017-07-01

    This work proposed a method to acquire regions of fruit, branch and leaf from red apple image in orchard. To acquire fruit image, R-G image was extracted from the RGB image for corrosive working, hole filling, subregion removal, expansive working and opening operation in order. Finally, fruit image was acquired by threshold segmentation. To acquire leaf image, fruit image was subtracted from RGB image before extracting 2G-R-B image. Then, leaf image was acquired by subregion removal and threshold segmentation. To acquire branch image, dynamic threshold segmentation was conducted in the R-G image. Then, the segmented image was added to fruit image to acquire adding fruit image which was subtracted from RGB image with leaf image. Finally, branch image was acquired by opening operation, subregion removal and threshold segmentation after extracting the R-G image from the subtracting image. Compared with previous methods, more complete image of fruit, leaf and branch can be acquired from red apple image with this method.

  2. Analysis of S-box in Image Encryption Using Root Mean Square Error Method

    Science.gov (United States)

    Hussain, Iqtadar; Shah, Tariq; Gondal, Muhammad Asif; Mahmood, Hasan

    2012-07-01

    The use of substitution boxes (S-boxes) in encryption applications has proven to be an effective nonlinear component in creating confusion and randomness. The S-box is evolving and many variants appear in literature, which include advanced encryption standard (AES) S-box, affine power affine (APA) S-box, Skipjack S-box, Gray S-box, Lui J S-box, residue prime number S-box, Xyi S-box, and S8 S-box. These S-boxes have algebraic and statistical properties which distinguish them from each other in terms of encryption strength. In some circumstances, the parameters from algebraic and statistical analysis yield results which do not provide clear evidence in distinguishing an S-box for an application to a particular set of data. In image encryption applications, the use of S-boxes needs special care because the visual analysis and perception of a viewer can sometimes identify artifacts embedded in the image. In addition to existing algebraic and statistical analysis already used for image encryption applications, we propose an application of root mean square error technique, which further elaborates the results and enables the analyst to vividly distinguish between the performances of various S-boxes. While the use of the root mean square error analysis in statistics has proven to be effective in determining the difference in original data and the processed data, its use in image encryption has shown promising results in estimating the strength of the encryption method. In this paper, we show the application of the root mean square error analysis to S-box image encryption. The parameters from this analysis are used in determining the strength of S-boxes

  3. A method for volumetric retinal tissue oxygen tension imaging.

    Science.gov (United States)

    Felder, Anthony E; Wanek, Justin; Teng, Pang-Yu; Blair, Norman P; Shahidi, Mahnaz

    2018-01-01

    Inadequate retinal oxygenation occurs in many vision-threatening retinal diseases, including diabetic retinopathy, retinal vascular occlusions, and age-related macular degeneration. Therefore, techniques that assess retinal oxygenation are necessary to understand retinal physiology in health and disease. The purpose of the current study is to report a method for the three-dimensional (3D) imaging of retinal tissue oxygen tension (tPO 2 ) in rats. Imaging was performed in Long Evans pigmented rats under systemic normoxia (N = 6) or hypoxia (N = 3). A vertical laser line was horizontally scanned on the retina and a series of optical section phase-delayed phosphorescence images were acquired. From these images, phosphorescence volumes at each phase delay were constructed and a 3D retinal tPO 2 volume was generated. Retinal tPO 2 volumes were quantitatively analyzed by generating retinal depth profiles of mean tPO 2 (M tPO2 ) and the spatial variation of tPO 2 (SV tPO2 ). The effects of systemic condition (normoxia/hypoxia) and retinal depth on M tPO2 and SV tPO2 were determined by mixed linear model. Each 3D retinal tPO 2 volume was approximately 500 × 750 × 200 μm (horizontal × vertical × depth) and consisted of 45 en face tPO 2 images through the retinal depth. M tPO2 at the chorioretinal interface was significantly correlated with systemic arterial oxygen tension (P = 0.007; N = 9). There were significant effects of both systemic condition and retinal depth on M tPO2 and SV tPO2 , such that both were lower under hypoxia than normoxia and higher in the outer retina than inner retina (P < 0.001). For the first time, 3D imaging of retinal tPO 2 was demonstrated, with potential future application for assessment of physiological alterations in animal models of retinal diseases.

  4. X-ray imaging using amorphous selenium: a photoinduced discharge readout method for digital mammography.

    Science.gov (United States)

    Rowlands, J A; Hunter, D M; Araj, N

    1991-01-01

    A new digital image readout method for electrostatic charge images on photoconductive plates is described. The method can be used to read out images on selenium plates similar to those used in xeromammography. The readout method, called the air-gap photoinduced discharge method (PID), discharges the latent image pixel by pixel and measures the charge. The PID readout method, like electrometer methods, is linear. However, the PID method permits much better resolution than scanning electrometers while maintaining quantum limited performance at high radiation exposure levels. Thus the air-gap PID method appears to be uniquely superior for high-resolution digital imaging tasks such as mammography.

  5. THz-SAR Vibrating Target Imaging via the Bayesian Method

    Directory of Open Access Journals (Sweden)

    Bin Deng

    2017-01-01

    Full Text Available Target vibration bears important information for target recognition, and terahertz, due to significant micro-Doppler effects, has strong advantages for remotely sensing vibrations. In this paper, the imaging characteristics of vibrating targets with THz-SAR are at first analyzed. An improved algorithm based on an excellent Bayesian approach, that is, the expansion-compression variance-component (ExCoV method, has been proposed for reconstructing scattering coefficients of vibrating targets, which provides more robust and efficient initialization and overcomes the deficiencies of sidelobes as well as artifacts arising from the traditional correlation method. A real vibration measurement experiment of idle cars was performed to validate the range model. Simulated SAR data of vibrating targets and a tank model in a real background in 220 GHz show good performance at low SNR. Rapidly evolving high-power terahertz devices will offer viable THz-SAR application at a distance of several kilometers.

  6. User evaluations offer promise for pod-intravaginal ring as a drug delivery platform: A mixed methods study of acceptability and use experiences.

    Science.gov (United States)

    Guthrie, Kate M; Rosen, Rochelle K; Vargas, Sara E; Getz, Melissa L; Dawson, Lauren; Guillen, Melissa; Ramirez, Jaime J; Baum, Marc M; Vincent, Kathleen L

    2018-01-01

    Effective HIV prevention requires efficient delivery of safe and efficacious drugs and optimization of user adherence. The user's experiences with the drug, delivery system, and use parameters are critical to product acceptability and adherence. Prevention product developers have the opportunity to directly control a drug delivery system and its impact on acceptability and adherence, as well as product efficacy. Involvement of potential users during preclinical design and development can facilitate this process. We embedded a mixed methods user evaluation study into a safety and pharmacokinetics (PK) trial of a pod-intravaginal ring delivering antiretroviral agents. Women enrolled in two cohorts, ultimately evaluating the safety/PK of a pod-IVRs delivering TDF-alone, TDF-FTC, and/or TDF-FTC-MVC. A 7-day use period was targeted for each pod-IVR, regardless of drug or drug combination. During the clinical study, participants provided both quantitative (i.e., survey) and qualitative (i.e., in-depth interview) data capturing acceptability, perceptibility, and adherence behaviors. Initial sexual and reproductive health history surveys, daily diaries, a final acceptability and willingness to use survey, and a qualitative in-depth interview comprised the user evaluation data for each pod-IVR experienced by the participants. Overall, the majority of participants (N = 10) reported being willing to use the pod-IVR platform for HIV prevention should it advance to market. Confidence to use the pod-IVR (e.g., insertion, removal) was high. There were no differences noted in the user experience of the pod-IVR platform; that is, whether the ring delivered TDF-alone, TDF-FTC, or TDF-FTC-MVC, users' experiences of the ring were similar and acceptable. Participants did report specific experiences, both sensory and behavioral, that impacted their use behaviors with respect to the ring, and which could ultimately impact acceptability and adherence. These experiences, and user

  7. A Promising PET Tracer for Imaging of α7 Nicotinic Acetylcholine Receptors in the Brain: Design, Synthesis, and in Vivo Evaluation of a Dibenzothiophene-Based Radioligand

    Directory of Open Access Journals (Sweden)

    Rodrigo Teodoro

    2015-10-01

    Full Text Available Changes in the expression of α7 nicotinic acetylcholine receptors (α7 nAChRs in the human brain are widely assumed to be associated with neurological and neurooncological processes. Investigation of these receptors in vivo depends on the availability of imaging agents such as radioactively labelled ligands applicable in positron emission tomography (PET. We report on a series of new ligands for α7 nAChRs designed by the combination of dibenzothiophene dioxide as a novel hydrogen bond acceptor functionality with diazabicyclononane as an established cationic center. To assess the structure-activity relationship (SAR of this new basic structure, we further modified the cationic center systematically by introduction of three different piperazine-based scaffolds. Based on in vitro binding affinity and selectivity, assessed by radioligand displacement studies at different rat and human nAChR subtypes and at the structurally related human 5-HT3 receptor, we selected the compound 7-(1,4-diazabicyclo[3.2.2]nonan-4-yl-2-fluorodibenzo-[b,d]thiophene 5,5-dioxide (10a for radiolabeling and further evaluation in vivo. Radiosynthesis of [18F]10a was optimized and transferred to an automated module. Dynamic PET imaging studies with [18F]10a in piglets and a monkey demonstrated high uptake of radioactivity in the brain, followed by washout and target-region specific accumulation under baseline conditions. Kinetic analysis of [18F]10a in pig was performed using a two-tissue compartment model with arterial-derived input function. Our initial evaluation revealed that the dibenzothiophene-based PET radioligand [18F]10a ([18F]DBT-10 has high potential to provide clinically relevant information about the expression and availability of α7 nAChR in the brain.

  8. Methods for calculating the electrode position Jacobian for impedance imaging.

    Science.gov (United States)

    Boyle, A; Crabb, M G; Jehl, M; Lionheart, W R B; Adler, A

    2017-03-01

    Electrical impedance tomography (EIT) or electrical resistivity tomography (ERT) current and measure voltages at the boundary of a domain through electrodes. The movement or incorrect placement of electrodes may lead to modelling errors that result in significant reconstructed image artifacts. These errors may be accounted for by allowing for electrode position estimates in the model. Movement may be reconstructed through a first-order approximation, the electrode position Jacobian. A reconstruction that incorporates electrode position estimates and conductivity can significantly reduce image artifacts. Conversely, if electrode position is ignored it can be difficult to distinguish true conductivity changes from reconstruction artifacts which may increase the risk of a flawed interpretation. In this work, we aim to determine the fastest, most accurate approach for estimating the electrode position Jacobian. Four methods of calculating the electrode position Jacobian were evaluated on a homogeneous halfspace. Results show that Fréchet derivative and rank-one update methods are competitive in computational efficiency but achieve different solutions for certain values of contact impedance and mesh density.

  9. Application of radiological imaging methods to radioactive waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tessaro, Ana Paula Gimenes; Souza, Daiane Cristini B. de; Vicente, Roberto, E-mail: aptessaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Radiological imaging technologies are most frequently used for medical diagnostic purposes but are also useful in materials characterization and other non-medical applications in research and industry. The characterization of radioactive waste packages or waste samples can also benefit from these techniques. In this paper, the application of some imaging methods is examined for the physical characterization of radioactive wastes constituted by spent ion-exchange resins and activated charcoal beds stored at the Radioactive Waste Management Department of IPEN. These wastes are generated when the filter media of the water polishing system of the IEA-R1 Nuclear Research Reactor is no longer able to maintain the required water quality and are replaced. The IEA-R1 is a 5MW pool-type reactor, moderated and cooled by light water, and fission and activation products released from the reactor core must be continuously removed to prevent activity buildup in the water. The replacement of the sorbents is carried out by pumping from the filter tanks into several 200 L drums, each drum getting a variable amount of water. Considering that the results of radioanalytical methods to determine the concentrations of radionuclides are usually expressed on dry basis,the amount of water must be known to calculate the total activity of each package. At first sight this is a trivial problem that demanded, however some effort to be solved. The findings on this subject are reported in this paper. (author)

  10. Quantifying Uncertainty in Near Surface Electromagnetic Imaging Using Bayesian Methods

    Science.gov (United States)

    Blatter, D. B.; Ray, A.; Key, K.

    2017-12-01

    Geoscientists commonly use electromagnetic methods to image the Earth's near surface. Field measurements of EM fields are made (often with the aid an artificial EM source) and then used to infer near surface electrical conductivity via a process known as inversion. In geophysics, the standard inversion tool kit is robust and can provide an estimate of the Earth's near surface conductivity that is both geologically reasonable and compatible with the measured field data. However, standard inverse methods struggle to provide a sense of the uncertainty in the estimate they provide. This is because the task of finding an Earth model that explains the data to within measurement error is non-unique - that is, there are many, many such models; but the standard methods provide only one "answer." An alternative method, known as Bayesian inversion, seeks to explore the full range of Earth model parameters that can adequately explain the measured data, rather than attempting to find a single, "ideal" model. Bayesian inverse methods can therefore provide a quantitative assessment of the uncertainty inherent in trying to infer near surface conductivity from noisy, measured field data. This study applies a Bayesian inverse method (called trans-dimensional Markov chain Monte Carlo) to transient airborne EM data previously collected over Taylor Valley - one of the McMurdo Dry Valleys in Antarctica. Our results confirm the reasonableness of previous estimates (made using standard methods) of near surface conductivity beneath Taylor Valley. In addition, we demonstrate quantitatively the uncertainty associated with those estimates. We demonstrate that Bayesian inverse methods can provide quantitative uncertainty to estimates of near surface conductivity.

  11. Correcting saturation of detectors for particle/droplet imaging methods

    International Nuclear Information System (INIS)

    Kalt, Peter A M

    2010-01-01

    Laser-based diagnostic methods are being applied to more and more flows of theoretical and practical interest and are revealing interesting new flow features. Imaging particles or droplets in nephelometry and laser sheet dropsizing methods requires a trade-off of maximized signal-to-noise ratio without over-saturating the detector. Droplet and particle imaging results in lognormal distribution of pixel intensities. It is possible to fit a derived lognormal distribution to the histogram of measured pixel intensities. If pixel intensities are clipped at a saturated value, it is possible to estimate a presumed probability density function (pdf) shape without the effects of saturation from the lognormal fit to the unsaturated histogram. Information about presumed shapes of the pixel intensity pdf is used to generate corrections that can be applied to data to account for saturation. The effects of even slight saturation are shown to be a significant source of error on the derived average. The influence of saturation on the derived root mean square (rms) is even more pronounced. It is found that errors on the determined average exceed 5% when the number of saturated samples exceeds 3% of the total. Errors on the rms are 20% for a similar saturation level. This study also attempts to delineate limits, within which the detector saturation can be accurately corrected. It is demonstrated that a simple method for reshaping the clipped part of the pixel intensity histogram makes accurate corrections to account for saturated pixels. These outcomes can be used to correct a saturated signal, quantify the effect of saturation on a derived average and offer a method to correct the derived average in the case of slight to moderate saturation of pixels

  12. A NOISE ADAPTIVE FUZZY EQUALIZATION METHOD FOR PROCESSING SOLAR EXTREME ULTRAVIOLET IMAGES

    Energy Technology Data Exchange (ETDEWEB)

    Druckmueller, M., E-mail: druckmuller@fme.vutbr.cz [Institute of Mathematics, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2, 616 69 Brno (Czech Republic)

    2013-08-15

    A new image enhancement tool ideally suited for the visualization of fine structures in extreme ultraviolet images of the corona is presented in this paper. The Noise Adaptive Fuzzy Equalization method is particularly suited for the exceptionally high dynamic range images from the Atmospheric Imaging Assembly instrument on the Solar Dynamics Observatory. This method produces artifact-free images and gives significantly better results than methods based on convolution or Fourier transform which are often used for that purpose.

  13. Comparing subjective image quality measurement methods for the creation of public databases

    Science.gov (United States)

    Redi, Judith; Liu, Hantao; Alers, Hani; Zunino, Rodolfo; Heynderickx, Ingrid

    2010-01-01

    The Single Stimulus (SS) method is often chosen to collect subjective data testing no-reference objective metrics, as it is straightforward to implement and well standardized. At the same time, it exhibits some drawbacks; spread between different assessors is relatively large, and the measured ratings depend on the quality range spanned by the test samples, hence the results from different experiments cannot easily be merged . The Quality Ruler (QR) method has been proposed to overcome these inconveniences. This paper compares the performance of the SS and QR method for pictures impaired by Gaussian blur. The research goal is, on one hand, to analyze the advantages and disadvantages of both methods for quality assessment and, on the other, to make quality data of blur impaired images publicly available. The obtained results show that the confidence intervals of the QR scores are narrower than those of the SS scores. This indicates that the QR method enhances consistency across assessors. Moreover, QR scores exhibit a higher linear correlation with the distortion applied. In summary, for the purpose of building datasets of subjective quality, the QR approach seems promising from the viewpoint of both consistency and repeatability.

  14. A method for visual inspection of welding by means of image processing of x-ray photograph

    International Nuclear Information System (INIS)

    Koshimizu, Hiroyasu; Yoshida, Tohru.

    1983-01-01

    Computer image processing is becoming a helpful tool even in industrial inspections. A computerized method for welding visual inspection is proposed in this paper. This method is based on computer image processing of X-ray photograph of welding, in which the appearance information of weldments such as shape of weld bead really exists. Structural patterns are extracted at first and seven computer measures for inspection are calculated using those patterns. Software system for visual inspection is constructed based on these seven measures. It was experimentally made clear that this system can provide a performance of more than 0.85 correlation to human visual inspection. As a result, the visual inspection by computer using X-ray photograph became a promising tool to realize objectivity and quantitativity of welding inspection. Additionally, the consistency of the system, the possibility to reduce computing costs, and so on are discussed to improve the proposed method. (author)

  15. Promising More Information

    Science.gov (United States)

    2003-01-01

    When NASA needed a real-time, online database system capable of tracking documentation changes in its propulsion test facilities, engineers at Stennis Space Center joined with ECT International, of Brookfield, Wisconsin, to create a solution. Through NASA's Dual-Use Program, ECT developed Exdata, a software program that works within the company's existing Promise software. Exdata not only satisfied NASA s requirements, but also expanded ECT s commercial product line. Promise, ECT s primary product, is an intelligent software program with specialized functions for designing and documenting electrical control systems. An addon to AutoCAD software, Promis e generates control system schematics, panel layouts, bills of material, wire lists, and terminal plans. The drawing functions include symbol libraries, macros, and automatic line breaking. Primary Promise customers include manufacturing companies, utilities, and other organizations with complex processes to control.

  16. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

    International Nuclear Information System (INIS)

    Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo; Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro; Kato, Rikio

    2005-01-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99m Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I AC μb with Chang's attenuation correction factor. The scatter component image is estimated by convolving I AC μb with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99m Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

  17. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

    Energy Technology Data Exchange (ETDEWEB)

    Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo [National Center for Geriatrics and Gerontology Research Institute, Department of Brain Science and Molecular Imaging, Obu, Aichi (Japan); Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro [National Cardiovascular Center Research Institute, Department of Investigative Radiology, Suita (Japan); Kato, Rikio [National Center for Geriatrics and Gerontology, Department of Radiology, Obu (Japan)

    2005-10-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with {sup 99m}Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I{sub AC}{sup {mu}}{sup b} with Chang's attenuation correction factor. The scatter component image is estimated by convolving I{sub AC}{sup {mu}}{sup b} with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and {sup 99m}Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

  18. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method.

    Science.gov (United States)

    Shidahara, Miho; Watabe, Hiroshi; Kim, Kyeong Min; Kato, Takashi; Kawatsu, Shoji; Kato, Rikio; Yoshimura, Kumiko; Iida, Hidehiro; Ito, Kengo

    2005-10-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99mTc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I(mub)AC with Chang's attenuation correction factor. The scatter component image is estimated by convolving I(mub)AC with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99mTc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine.

  19. [Imaging of pleural diseases: evaluation of imaging methods based on chest radiography].

    Science.gov (United States)

    Poyraz, Necdet; Kalkan, Havva; Ödev, Kemal; Ceran, Sami

    2017-03-01

    The most commonly employed radiologic method in diagnosis of pleural diseases is conventional chest radiograph. The commonest chest- X-Ray findings are the presence of pleural effusion and thickening. Small pleural effusions are not readily identified on posteroanterior chest radiograph. However, lateral decubitus chest radiograph and chest ultrasonography may show small pleural effusions. These are more efficient methods than posteroanterior chest radiograph in the erect position for demonstrating small amounts of free pleural effusions. Chest ultrasonograph may be able to help in distinguishing the pleural pathologies from parenchymal lesions. On chest radiograph pleural effusions or pleural thickening may obscure the visibility of the underlying disease or parenchymal abnormality. Thus, computed tomography (CT) may provide additional information of determining the extent and severity of pleural disease and may help to differentiate malign pleural lesions from the benign ones. Moreover, CT may provide the differentiation of parenchmal abnormalities from pleural pathologies. CT (coronal and sagittal reformatted images) that also show invasion of chest wall, mediastinum and diaphragm, as well as enlarged hilar or mediastinal lymph nodes. Standart non-invasive imaging techniques may be supplemented with magnetic resonans imaging (MRI).

  20. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality--preliminary findings.

    Science.gov (United States)

    Miéville, Frédéric A; Gudinchet, François; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Bochud, François O; Verdun, Francis R

    2011-09-01

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI(vol) 4.8-7.9 mGy, DLP 37.1-178.9 mGy·cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p ASIR above 50%, image quality significantly decreased (p ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone.

  1. An improved method for polarimetric image restoration in interferometry

    Science.gov (United States)

    Pratley, Luke; Johnston-Hollitt, Melanie

    2016-11-01

    Interferometric radio astronomy data require the effects of limited coverage in the Fourier plane to be accounted for via a deconvolution process. For the last 40 years this process, known as `cleaning', has been performed almost exclusively on all Stokes parameters individually as if they were independent scalar images. However, here we demonstrate for the case of the linear polarization P, this approach fails to properly account for the complex vector nature resulting in a process which is dependent on the axes under which the deconvolution is performed. We present here an improved method, `Generalized Complex CLEAN', which properly accounts for the complex vector nature of polarized emission and is invariant under rotations of the deconvolution axes. We use two Australia Telescope Compact Array data sets to test standard and complex CLEAN versions of the Högbom and SDI (Steer-Dwedney-Ito) CLEAN algorithms. We show that in general the complex CLEAN version of each algorithm produces more accurate clean components with fewer spurious detections and lower computation cost due to reduced iterations than the current methods. In particular, we find that the complex SDI CLEAN produces the best results for diffuse polarized sources as compared with standard CLEAN algorithms and other complex CLEAN algorithms. Given the move to wide-field, high-resolution polarimetric imaging with future telescopes such as the Square Kilometre Array, we suggest that Generalized Complex CLEAN should be adopted as the deconvolution method for all future polarimetric surveys and in particular that the complex version of an SDI CLEAN should be used.

  2. The narrow-band imaging examination method in otorhinolaryngology

    Directory of Open Access Journals (Sweden)

    Robert Šifrer

    2013-10-01

    Full Text Available Early diagnostics could improve the prognosis of patients with squamous-cell carcinomas of the head and neck. Narrow-Band Imaging (NBI is the latest examination method in the group of biologic endoscopies. NBI improves the distinction between malignant and benign mucosal lesions. Early suspect oncologic lesions that may otherwise be missed by normal white light illumination can also be diagnosed. The biggest benefit of NBI technology is achieved by using it together with a HDTV camera that enables better contrast and higher resolution. NBI is based on better imaging of superficial mucosal vasculature. The biologic potential of mucosal lesions could be predicted from vascular changes. The colour of normal mucosa under NBI is blue and green and the vessels show no pathological features. Well-demarcated brownish areas and scattered thick dark spots and abnormal winding and branching out of vessels on the mucosa are all oncologically suspicious features. Authors report the experience from literature on the use of NBI to identify carcinomas of the oral cavity, epipharynx, oropharynx, hypopharynx and larynx and evaluation of unknown primaries. In addition, the literature reports the benefit of NBI in identifying early stage carcinomas in previously irradiated patients. Persistence and recurrence of carcinoma and the development of new primary tumour could easily be missed by using only standard white-light illumination. The method proved to be highly sensitive and specific for predicting malignant changes in the above-mentioned circumstances. Authors report their own experience with NBI technology as well. For further improvement of the method, new technologic development is expected to enable the connection of NBI and HDTV with flexible endoscopes.

  3. Evaluation of the Accuracy of the Dark Frame Subtraction Method in CCD Image Processing

    National Research Council Canada - National Science Library

    Levesque, Martin P; Lelievre, Mario

    2007-01-01

    .... This method is frequently used for removing the image background gradient (a thermal artefact) in CCD images. This report demonstrates that this method may not be suitable for the detection of objects with very low signal-to-noise ratio...

  4. An improved computing method for the image edge detection

    Institute of Scientific and Technical Information of China (English)

    Gang Wang; Liang Xiao; Anzhi He

    2007-01-01

    The framework of detecting the image edge based on the sub-pixel multi-fractal measure (SPMM) is presented. The measure is defined, which gives the sub-pixel local distribution of the image gradient. The more precise singularity exponent of every pixel can be obtained by performing the SPMM analysis on the image. Using the singularity exponents and the multi-fractal spectrum of the image, the image can be segmented into a series of sets with different singularity exponents, thus the image edge can be detected automatically and easily. The simulation results show that the SPMM has higher quality factor in the image edge detection.

  5. Equipment and methods for synthetic aperture anatomic and flow imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Nikolov, Svetoslav; Misaridis, Thanassis

    2002-01-01

    Conventional ultrasound imaging is done by sequentially probing in each image direction. The frame rate is, thus, limited by the speed of sound and the number of lines necessary to form an image. This is especially limiting in flow imaging, since multiple lines are used for flow estimation. Another...... problem is that each receiving transducer element must be connected to a receiver, which makes the expansion of the number of receive channels expensive. Synthetic aperture (SA) imaging is a radical change from the sequential image formation. Here ultrasound is emitted in all directions and the image...... is formed in all directions simultaneously over a number of acquisitions. SA images can therefore be perfectly focused in both transmit and receive for all depths, thus significantly improving image quality. A further advantage is that very fast imaging can be done, since only a few emissions are needed...

  6. A method for generating high resolution satellite image time series

    Science.gov (United States)

    Guo, Tao

    2014-10-01

    There is an increasing demand for satellite remote sensing data with both high spatial and temporal resolution in many applications. But it still is a challenge to simultaneously improve spatial resolution and temporal frequency due to the technical limits of current satellite observation systems. To this end, much R&D efforts have been ongoing for years and lead to some successes roughly in two aspects, one includes super resolution, pan-sharpen etc. methods which can effectively enhance the spatial resolution and generate good visual effects, but hardly preserve spectral signatures and result in inadequate analytical value, on the other hand, time interpolation is a straight forward method to increase temporal frequency, however it increase little informative contents in fact. In this paper we presented a novel method to simulate high resolution time series data by combing low resolution time series data and a very small number of high resolution data only. Our method starts with a pair of high and low resolution data set, and then a spatial registration is done by introducing LDA model to map high and low resolution pixels correspondingly. Afterwards, temporal change information is captured through a comparison of low resolution time series data, and then projected onto the high resolution data plane and assigned to each high resolution pixel according to the predefined temporal change patterns of each type of ground objects. Finally the simulated high resolution data is generated. A preliminary experiment shows that our method can simulate a high resolution data with a reasonable accuracy. The contribution of our method is to enable timely monitoring of temporal changes through analysis of time sequence of low resolution images only, and usage of costly high resolution data can be reduces as much as possible, and it presents a highly effective way to build up an economically operational monitoring solution for agriculture, forest, land use investigation

  7. Quantitative Clinical Imaging Methods for Monitoring Intratumoral Evolution.

    Science.gov (United States)

    Kim, Joo Yeun; Gatenby, Robert A

    2017-01-01

    regional dynamics so that the internal diversity of tumors is the net result of complex multiscale somatic Darwinian interactions.Methods in landscape ecology harness Darwinian dynamics to link the environmental properties of a given region to the local populations which are assumed to represent maximally fit phenotypes within those conditions. Consider a common task of a landscape ecologist: defining the spatial distribution of species in a large region, e.g., in a satellite image. Clearly the most accurate approach requires a meter by meter survey of the multiple square kilometers in the region of interest. However, this is both impractical and potentially destructive. Instead, landscape ecology breaks the task into component parts relying on the Darwinian interdependence of environmental properties and fitness of specific species' phenotypic and genotypic properties. First, the satellite map is carefully analyzed to define the number and distribution of habitats. Then the species distribution in a representative sampling of each habitat is empirically determined. Ultimately, this permits sufficient bridging of spatial scales to accurately predict spatial distribution of plant and animal species within large regions.Currently, identifying intratumoral subpopulations requires detailed histological and molecular studies that are expensive and time consuming. Furthermore, this method is subject to sampling bias, is invasive for vital organs such as the brain, and inherently destructive precluding repeated assessments for monitoring post-treatment response and proteogenomic evolution. In contrast, modern cross-sectional imaging can interrogate the entire tumor noninvasively, allowing repeated analysis without disrupting the region of interest. In particular, magnetic resonance imaging (MRI) provides exceptional spatial resolution and generates signals that are unique to the molecular constituents of tissue. Here we propose that MRI scans may be the equivalent of satellite

  8. A Frequency Matching Method for Generation of a Priori Sample Models from Training Images

    DEFF Research Database (Denmark)

    Lange, Katrine; Cordua, Knud Skou; Frydendall, Jan

    2011-01-01

    This paper presents a Frequency Matching Method (FMM) for generation of a priori sample models based on training images and illustrates its use by an example. In geostatistics, training images are used to represent a priori knowledge or expectations of models, and the FMM can be used to generate...... new images that share the same multi-point statistics as a given training image. The FMM proceeds by iteratively updating voxel values of an image until the frequency of patterns in the image matches the frequency of patterns in the training image; making the resulting image statistically...... indistinguishable from the training image....

  9. Methods of evaluating SPECT images. The usefulness of the Matsuda`s method by the Patlak plot method in children

    Energy Technology Data Exchange (ETDEWEB)

    Takaishi, Yasuko [Nippon Medical School, Tokyo (Japan); Hashimoto, Kiyoshi; Fujino, Osamu [and others

    1998-11-01

    Single photon emission computed tomography (SPECT) is a tool to study cerebral blood flow (CBF) kinetics. There are three methods of evaluating SPECT images: visual, semi-quantitative (evaluation of the radioactivity ratio of the cerebral region to the cerebellum (R/CE) or to the thalamus (R/TH)) and quantitative (Matsuda`s method by Patlak plot method using {sup 99m}Tc-hexamethylpropylene amine oxime radionuclide angiography). We evaluated SPECT images by the quantitative method in 14 patients with neurological disorders and examined the correlation of the results to those obtained by the semi-quantitative method. There was no significant correlation between the R/CE or R/TH ratio and regional CBF except two regions. The evaluation by the semi-quantitative method may have been inappropriate, probably because the cerebellar or thalamic blood flow was not constant in each case. Evaluation by the quantitative method, on the other hand, seemed to be useful not only for the comparison of CBF among normal subjects, but also in the demonstration of progressive changes of CBF in the same case. The Matsuda`s method by the Patlak plot method is suitable for examination of children, since it dose not require aortic blood sampling. (author)

  10. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    Richey, J.B.; Wake, R.H.; Walters, R.G.; Hunt, W.F.; Cool, S.L.

    1980-01-01

    The invention relates to cardiac imaging systems and methods employing computerised tomographic scanning. Apparatus is described which allows an image of the radiation attenuation of the heart at a desired phase of the cardiac cycle. The patients ECG signal can be used in a transverse-and-rotate type CT scanner as a time base, so that the beam reaches the heart at a desired phase of the cardiac cycle, or, in a purely rotational-type CT scanner continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves by shuttering or switching the power supply can be controlled by the ECG signal. A pacemaker is used to stabilize the cardiac period. Also used is a system for recognising unacceptable variations in the cardiac period and discarding corresponding scan data. In a transverse-and-rotate type fan-beam CT scanner, the effective beam width is narrowed to reduce the duration of the traverse of the heart. (U.K.)

  11. Methods of Hematoxylin and Erosin Image Information Acquisition and Optimization in Confocal Microscopy.

    Science.gov (United States)

    Yoon, Woong Bae; Kim, Hyunjin; Kim, Kwang Gi; Choi, Yongdoo; Chang, Hee Jin; Sohn, Dae Kyung

    2016-07-01

    We produced hematoxylin and eosin (H&E) staining-like color images by using confocal laser scanning microscopy (CLSM), which can obtain the same or more information in comparison to conventional tissue staining. We improved images by using several image converting techniques, including morphological methods, color space conversion methods, and segmentation methods. An image obtained after image processing showed coloring very similar to that in images produced by H&E staining, and it is advantageous to conduct analysis through fluorescent dye imaging and microscopy rather than analysis based on single microscopic imaging. The colors used in CLSM are different from those seen in H&E staining, which is the method most widely used for pathologic diagnosis and is familiar to pathologists. Computer technology can facilitate the conversion of images by CLSM to be very similar to H&E staining images. We believe that the technique used in this study has great potential for application in clinical tissue analysis.

  12. Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography.

    Science.gov (United States)

    Lin, Kuo-Shyan; Ding, Yu-Shin; Kim, Sung-Won; Kil, Kun-Eek

    2005-05-01

    Racemic and enantiomerically pure ((S,S) and (R,R)) 2-[alpha-(2-(2-[(18)F]fluoroethoxy)phenoxy)benzyl]morpholine ([(18)F]FRB) and its tetradeuterated form [(18)F]FRB-D(4), analogs of the highly selective norepinephrine reuptake inhibitor reboxetine (2-[alpha-(2-ethoxyphenoxy)benzyl]morpholine, RB), have been synthesized for studies of norepinephrine transporter (NET) system with positron emission tomography (PET). The [(18)F]fluorinated precursor, (S,S)/(R,R)-N-tert-butyloxycarbonyl-2-[alpha-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-N-Boc-desethylRB), was prepared by the N-protection of (S,S)/(R,R)-2-[alpha-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-desethylRB) with a tert-butyloxycarbonyl (Boc) group followed by enantiomeric resolution with chiral HPLC to provide both (S,S) and (R,R) enantiomers with >99% enantiomeric purity. These compounds were then used for radiosynthesis to prepare enantiomerically pure [(18)F]FRB and [(18)F]FRB-D(4) via the following three-step procedure: (1) formation of 1-bromo-2-[(18)F]fluoroethane ([(18)F]BFE or [(18)F]BFE-D(4)) by nucleophilic displacement of 2-bromoethyl triflate (or D(4) analog) with no-carrier added [(18)F]F(-) in THF; (2) reaction of [(18)F]BFE (or [(18)F]BFE-D(4)) with N-Boc-desethylRB in DMF in the presence of excess base; and (3) deprotection with trifluoroacetic acid. The racemates, (S,S) and (R,R) enantiomers of [(18)F]FRB and [(18)F]FRB-D(4) were obtained in 11-27% (decay corrected to the end of bombardment, EOB) in 120-min synthesis time with a radiochemical purity of >98% and specific activities of 21-48 GBq/micromol (EOB). The results of the whole-body biodistribution studies with (S,S)-[(18)F]FRB-D(4) were similar to those with (S,S)-[(18)F]FRB but showed relatively faster blood clearance and no significant in vivo defluorination. Positron emission tomography studies in baboon brain also showed that (S,S)-[(18)F]FRB-D(4) may be a potentially useful ligand for imaging NET with PET.

  13. Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography

    International Nuclear Information System (INIS)

    Lin, K.-S.; Ding, Y.-S.; Kim, Sung-Won; Kil, Kun-Eek

    2005-01-01

    Racemic and enantiomerically pure ((S,S) and (R,R)) 2-[α-(2-(2-[ 18 F]fluoroethoxy)phenoxy)benzyl]morpholine ([ 18 F]FRB) and its tetradeuterated form [ 18 F]FRB-D 4 , analogs of the highly selective norepinephrine reuptake inhibitor reboxetine (2-[α-(2-ethoxyphenoxy)benzyl]morpholine, RB), have been synthesized for studies of norepinephrine transporter (NET) system with positron emission tomography (PET). The [ 18 F]fluorinated precursor, (S,S)/(R,R)-N-tert-butyloxycarbonyl-2-[α-(2-hydroxyphenoxy)benzyl] morpholine ((S,S)/(R,R)-N-Boc-desethylRB), was prepared by the N-protection of (S,S)/(R,R)-2-[α-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-desethylRB) with a tert-butyloxycarbonyl (Boc) group followed by enantiomeric resolution with chiral HPLC to provide both (S,S) and (R,R) enantiomers with >99% enantiomeric purity. These compounds were then used for radiosynthesis to prepare enantiomerically pure [ 18 F]FRB and [ 18 F]FRB-D 4 via the following three-step procedure: (1) formation of 1-bromo-2-[ 18 F]fluoroethane ([ 18 F]BFE or [ 18 F]BFE-D 4 ) by nucleophilic displacement of 2-bromoethyl triflate (or D 4 analog) with no-carrier added [ 18 F]F - in THF; (2) reaction of [ 18 F]BFE (or [ 18 F]BFE-D 4 ) with N-Boc-desethylRB in DMF in the presence of excess base; and (3) deprotection with trifluoroacetic acid. The racemates, (S,S) and (R,R) enantiomers of [ 18 F]FRB and [ 18 F]FRB-D 4 were obtained in 11-27% (decay corrected to the end of bombardment, EOB) in 120-min synthesis time with a radiochemical purity of >98% and specific activities of 21-48 GBq/μmol (EOB). The results of the whole-body biodistribution studies with (S,S)-[ 18 F]FRB-D 4 were similar to those with (S,S)-[ 18 F]FRB but showed relatively faster blood clearance and no significant in vivo defluorination. Positron emission tomography studies in baboon brain also showed that (S,S)-[ 18 F]FRB-D 4 may be a potentially useful ligand for imaging NET with PET

  14. Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, K.-S. [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Ding, Y.-S. [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)]. E-mail: ding@bnl.gov; Kim, Sung-Won [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kil, Kun-Eek [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2005-05-01

    showed that (S,S)-[{sup 18}F]FRB-D{sub 4} may be a potentially useful ligand for imaging NET with PET.

  15. Advanced methods and algorithm for high precision astronomical imaging

    International Nuclear Information System (INIS)

    Ngole-Mboula, Fred-Maurice

    2016-01-01

    One of the biggest challenges of modern cosmology is to gain a more precise knowledge of the dark energy and the dark matter nature. Fortunately, the dark matter can be traced directly through its gravitational effect on galaxies shapes. The European Spatial Agency Euclid mission will precisely provide data for such a purpose. A critical step is analyzing these data will be to accurately model the instrument Point Spread Function (PSF), which the focus of this thesis.We developed non parametric methods to reliably estimate the PSFs across an instrument field-of-view, based on unresolved stars images and accounting for noise, under sampling and PSFs spatial variability. At the core of these contributions, modern mathematical tools and concepts such as sparsity. An important extension of this work will be to account for the PSFs wavelength dependency. (author) [fr

  16. In vivo cellular imaging using fluorescent proteins - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    M. Monti

    2012-12-01

    Full Text Available The discovery and genetic engineering of fluorescent proteins has revolutionized cell biology. What was previously invisible to the cell often can be made visible with the use of fluorescent proteins. With this words, Robert M. Hoffman introduces In vivo Cellular Imaging Using Fluorescent proteins, the eighteen chapters book dedicated to the description of how fluorescence proteins have changed the way to analyze cellular processes in vivo. Modern researches aim to study new and less invasive methods able to follow the behavior of different cell types in different biological contexts: for example, how cancer cells migrate or how they respond to different therapies. Also, in vivo systems can help researchers to better understand animal embryonic development so as how fluorescence proteins may be used to monitor different processes in living organisms at the molecular and cellular level.

  17. Microfluidic method for measuring viscosity using images from smartphone

    Science.gov (United States)

    Kim, Sooyeong; Kim, Kyung Chun; Yeom, Eunseop

    2018-05-01

    The viscosity of a fluid is the most important characteristic in fluid rheology. Many microfluidic devices have been proposed for easily measuring the fluid viscosity of small samples. A hybrid system consisting of a smartphone and microfluidic device can offer a mobile laboratory for performing a wide range of detection and analysis functions related to healthcare. In this study, a new mobile sensing method based on a microfluidic device was proposed for fluid viscosity measurements. By separately delivering sample and reference fluids into the two inlets of a Y-shaped microfluidic device, an interfacial line is induced at downstream of the device. Because the interfacial width (W) between the sample and reference fluid flows was determined by their pressure ratio, the viscosity (μ) of the sample could be estimated by measuring the interfacial width. To distinguish the interfacial width of a sample, optical images of the flows at downstream of the Y-shaped microfluidic device were acquired using a smartphone. To check the measurement accuracy of the proposed method, the viscosities of glycerol mixtures were compared with those measured by a conventional viscometer. The proposed technique was applied to monitor the variations in blood and oil samples depending on storage or rancidity. We expect that this mobile sensing method based on a microfluidic device could be utilized as a viscometer with significant advantages in terms of mobility, ease-of-operation, and data management.

  18. Unconventional Imaging Methods to Capture Transient Structures during Actomyosin Interaction

    Directory of Open Access Journals (Sweden)

    Eisaku Katayama

    2018-05-01

    Full Text Available Half a century has passed since the cross-bridge structure was recognized as the molecular machine that generates muscle tension. Despite various approaches by a number of scientists, information on the structural changes in the myosin heads, particularly its transient configurations, remains scant even now, in part because of their small size and rapid stochastic movements during the power stroke. Though progress in cryo-electron microscopy is eagerly awaited as the ultimate means to elucidate structural details, the introduction of some unconventional methods that provide high-contrast raw images of the target protein assemblies is quite useful, if available, to break the current impasse. Quick-freeze deep–etch–replica electron microscopy coupled with dedicated image analysis procedures, and high-speed atomic-force microscopy are two such candidates. We have applied the former to visualize actin-associated myosin heads under in vitro motility assay conditions, and found that they take novel configurations similar to the SH1–SH2-crosslinked myosin that we characterized recently. By incorporating biochemical and biophysical results, we have revised the cross-bridge mechanism to involve the new conformer as an important main player. The latter “microscopy” is unique and advantageous enabling continuous observation of various protein assemblies as they function. Direct observation of myosin-V’s movement along actin filaments revealed several unexpected behaviors such as foot-stomping of the leading head and unwinding of the coiled-coil tail. The potential contribution of these methods with intermediate spatial resolution is discussed.

  19. Local coding based matching kernel method for image classification.

    Directory of Open Access Journals (Sweden)

    Yan Song

    Full Text Available This paper mainly focuses on how to effectively and efficiently measure visual similarity for local feature based representation. Among existing methods, metrics based on Bag of Visual Word (BoV techniques are efficient and conceptually simple, at the expense of effectiveness. By contrast, kernel based metrics are more effective, but at the cost of greater computational complexity and increased storage requirements. We show that a unified visual matching framework can be developed to encompass both BoV and kernel based metrics, in which local kernel plays an important role between feature pairs or between features and their reconstruction. Generally, local kernels are defined using Euclidean distance or its derivatives, based either explicitly or implicitly on an assumption of Gaussian noise. However, local features such as SIFT and HoG often follow a heavy-tailed distribution which tends to undermine the motivation behind Euclidean metrics. Motivated by recent advances in feature coding techniques, a novel efficient local coding based matching kernel (LCMK method is proposed. This exploits the manifold structures in Hilbert space derived from local kernels. The proposed method combines advantages of both BoV and kernel based metrics, and achieves a linear computational complexity. This enables efficient and scalable visual matching to be performed on large scale image sets. To evaluate the effectiveness of the proposed LCMK method, we conduct extensive experiments with widely used benchmark datasets, including 15-Scenes, Caltech101/256, PASCAL VOC 2007 and 2011 datasets. Experimental results confirm the effectiveness of the relatively efficient LCMK method.

  20. The promise and problems of non-physician practitioners in general surgery education: Results of a multi-center, mixed-methods study of faculty.

    Science.gov (United States)

    Coverdill, James E; Shelton, Jeff Scott; Alseidi, Adnan; Borgstrom, David C; Dent, Daniel L; Dumire, Russell; Fryer, Jonathan; Hartranft, Thomas H; Holsten, Steven B; Nelson, M Timothy; Shabahang, Mohsen M; Sherman, Stanley R; Termuhlen, Paula M; Woods, Randy J; Mellinger, John D

    2018-02-01

    Nurse Practitioners and Physician Assistants - called non-physician practitioners or NPPs - are common, but little is known about their educational promise and problems. General surgery faculty in 13 residency programs were surveyed (N = 279 with a 71% response rate) and interviewed (N = 43) about experiences with NPPs. The survey documents overall patterns and differences by program type and primary service; interviews point to deeper rationales and concerns. NPPs reduce faculty and resident workloads and teach residents. NPPs also reduce resident exposure to educationally valuable activities, and faculty sometimes round, make decisions, and operate with NPPs instead of residents. Interviews indicate that NPPs can overly reduce resident involvement in patient care, diminish resident responsibility and decision making, disrupt team dynamics, and compete for procedures. NPPs both enhance and hinder surgical education and highlight the need to more clearly articulate learning outcomes for residents and activities necessary to achieve those outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. An Efficient Seam Elimination Method for UAV Images Based on Wallis Dodging and Gaussian Distance Weight Enhancement.

    Science.gov (United States)

    Tian, Jinyan; Li, Xiaojuan; Duan, Fuzhou; Wang, Junqian; Ou, Yang

    2016-05-10

    The rapid development of Unmanned Aerial Vehicle (UAV) remote sensing conforms to the increasing demand for the low-altitude very high resolution (VHR) image data. However, high processing speed of massive UAV data has become an indispensable prerequisite for its applications in various industry sectors. In this paper, we developed an effective and efficient seam elimination approach for UAV images based on Wallis dodging and Gaussian distance weight enhancement (WD-GDWE). The method encompasses two major steps: first, Wallis dodging was introduced to adjust the difference of brightness between the two matched images, and the parameters in the algorithm were derived in this study. Second, a Gaussian distance weight distribution method was proposed to fuse the two matched images in the overlap region based on the theory of the First Law of Geography, which can share the partial dislocation in the seam to the whole overlap region with an effect of smooth transition. This method was validated at a study site located in Hanwang (Sichuan, China) which was a seriously damaged area in the 12 May 2008 enchuan Earthquake. Then, a performance comparison between WD-GDWE and the other five classical seam elimination algorithms in the aspect of efficiency and effectiveness was conducted. Results showed that WD-GDWE is not only efficient, but also has a satisfactory effectiveness. This method is promising in advancing the applications in UAV industry especially in emergency situations.

  2. A fast and automatic mosaic method for high-resolution satellite images

    Science.gov (United States)

    Chen, Hongshun; He, Hui; Xiao, Hongyu; Huang, Jing

    2015-12-01

    We proposed a fast and fully automatic mosaic method for high-resolution satellite images. First, the overlapped rectangle is computed according to geographical locations of the reference and mosaic images and feature points on both the reference and mosaic images are extracted by a scale-invariant feature transform (SIFT) algorithm only from the overlapped region. Then, the RANSAC method is used to match feature points of both images. Finally, the two images are fused into a seamlessly panoramic image by the simple linear weighted fusion method or other method. The proposed method is implemented in C++ language based on OpenCV and GDAL, and tested by Worldview-2 multispectral images with a spatial resolution of 2 meters. Results show that the proposed method can detect feature points efficiently and mosaic images automatically.

  3. High-performance method of morphological medical image processing

    Directory of Open Access Journals (Sweden)

    Ryabykh M. S.

    2016-07-01

    Full Text Available the article shows the implementation of grayscale morphology vHGW algorithm for selection borders in the medical image. Image processing is executed using OpenMP and NVIDIA CUDA technology for images with different resolution and different size of the structuring element.

  4. Novel axolotl cardiac function analysis method using magnetic resonance imaging

    NARCIS (Netherlands)

    Sanches, Pedro Gomes; Op 't Veld, Roel C.; de Graaf, Wolter; Strijkers, Gustav J.; Grüll, Holger

    2017-01-01

    The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a non-invasive technique to image heart function

  5. Novel axolotl cardiac function analysis method using magnetic resonance imaging

    NARCIS (Netherlands)

    Sanches, P.G.; Op ‘t Veld, R.C.; de Graaf, W.; Strijkers, G.J.; Grüll, H.

    2017-01-01

    The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a noninvasive technique to image heart function of

  6. Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods

    Directory of Open Access Journals (Sweden)

    Barbosa JA

    2011-05-01

    Full Text Available José Augusto A Barbosa¹, Alexandre B Rodrigues¹, Cleonice Carvalho C Mota¹, Márcia M Barbosa², Ana C Simões e Silva¹¹Department of Pediatrics, Faculty of Medicine, Federal University of Minas Gerais (UFMG, Belo Horizonte, Minas Gerais, Brazil; ²Ecocenter, Socor Hospital, Belo Horizonte, Minas Gerais, BrazilAbstract: Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.Keywords: cardiovascular risk, endothelium dysfunction, obesity, strain and strain rate, tissue Doppler

  7. The Z-isomer of 11{beta}-methoxy-17{alpha}-[{sup 123}I]iodovinylestradiol is a promising radioligand for estrogen receptor imaging in human breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rijks, Leonie J. M.; Boer, Gerard J.; Endert, Erik; Bruin, Kora de; Janssen, Anton G. M.; Royen, Eric A. van

    1997-01-01

    The potential of both stereoisomers of 11{beta}-methoxy-17{alpha}-[{sup 123}I]iodovinylestradiol (E- and Z-[{sup 123}I]MIVE) as suitable radioligands for imaging of estrogen receptor(ER)-positive human breast tumours was studied. The 17{alpha}-[{sup 123}I]iodovinylestradiol derivatives were prepared stereospecifically by oxidative radioiododestannylation of the corresponding 17{alpha}-tri-n-butylstannylvinylestradiol precursors. Both isomers of MIVE showed high in vitro affinity for dimethylbenzanthracene-induced rat and fresh human mammary tumour ER, that of Z-MIVE however being manyfold higher than that of E-MIVE. In vivo distribution studies with E- and Z-[{sup 123}I]MIVE in normal and tumour-bearing female rats showed ER-mediated uptake and retention in uterus, ovaries, pituitary, hypothalamus and mammary tumours, again the highest for Z-[{sup 123}I]MIVE. The uterus- and tumour-to-nontarget tissue (fat, muscle) uptake ratios were also highest for Z-[{sup 123}I]MIVE. Additionally, planar whole body imaging of two breast cancer patients 1-2 h after injection of Z-[{sup 123}I]MIVE showed increased focal uptake at known tumour sites. Therefore, we conclude that Z-[{sup 123}I]MIVE is a promising radioligand for the diagnostic imaging of ER in human breast cancer.

  8. A preconditioned inexact newton method for nonlinear sparse electromagnetic imaging

    KAUST Repository

    Desmal, Abdulla

    2015-03-01

    A nonlinear inversion scheme for the electromagnetic microwave imaging of domains with sparse content is proposed. Scattering equations are constructed using a contrast-source (CS) formulation. The proposed method uses an inexact Newton (IN) scheme to tackle the nonlinearity of these equations. At every IN iteration, a system of equations, which involves the Frechet derivative (FD) matrix of the CS operator, is solved for the IN step. A sparsity constraint is enforced on the solution via thresholded Landweber iterations, and the convergence is significantly increased using a preconditioner that levels the FD matrix\\'s singular values associated with contrast and equivalent currents. To increase the accuracy, the weight of the regularization\\'s penalty term is reduced during the IN iterations consistently with the scheme\\'s quadratic convergence. At the end of each IN iteration, an additional thresholding, which removes small \\'ripples\\' that are produced by the IN step, is applied to maintain the solution\\'s sparsity. Numerical results demonstrate the applicability of the proposed method in recovering sparse and discontinuous dielectric profiles with high contrast values.

  9. MEASUREMENTS OF STRAIN FIELDS DUE TO NANOSCALE PRECIPITATES USING THE PHASE IMAGE METHOD

    Directory of Open Access Journals (Sweden)

    Patricia Donnadieu

    2011-05-01

    Full Text Available Owing the phase image method (Hytch, 1998, strain fields can be derived from HREM images. The method is here applied to the nanoscale precipitates responsible for hardening in Aluminum alloys. Since the method is a very sensitive one, we have examined the impact of several aspects of the image quality (noise, fluctuations, distortion. The strain field information derived from the HREM image analysis is further introduced in a simulation of the dislocation motion in the matrix.

  10. A simple method for detecting tumor in T2-weighted MRI brain images. An image-based analysis

    International Nuclear Information System (INIS)

    Lau, Phooi-Yee; Ozawa, Shinji

    2006-01-01

    The objective of this paper is to present a decision support system which uses a computer-based procedure to detect tumor blocks or lesions in digitized medical images. The authors developed a simple method with a low computation effort to detect tumors on T2-weighted Magnetic Resonance Imaging (MRI) brain images, focusing on the connection between the spatial pixel value and tumor properties from four different perspectives: cases having minuscule differences between two images using a fixed block-based method, tumor shape and size using the edge and binary images, tumor properties based on texture values using spatial pixel intensity distribution controlled by a global discriminate value, and the occurrence of content-specific tumor pixel for threshold images. Measurements of the following medical datasets were performed: different time interval images, and different brain disease images on single and multiple slice images. Experimental results have revealed that our proposed technique incurred an overall error smaller than those in other proposed methods. In particular, the proposed method allowed decrements of false alarm and missed alarm errors, which demonstrate the effectiveness of our proposed technique. In this paper, we also present a prototype system, known as PCB, to evaluate the performance of the proposed methods by actual experiments, comparing the detection accuracy and system performance. (author)

  11. PREFACE: Anti-counterfeit Image Analysis Methods (A Special Session of ICSXII)

    Science.gov (United States)

    Javidi, B.; Fournel, T.

    2007-06-01

    The International Congress for Stereology is dedicated to theoretical and applied aspects of stochastic tools, image analysis and mathematical morphology. A special emphasis on `anti-counterfeit image analysis methods' has been given this year for the XIIth edition (ICSXII). Facing the economic and social threat of counterfeiting, this devoted session presents recent advances and original solutions in the field. A first group of methods are related to marks located either on the product (physical marks) or on the data (hidden information) to be protected. These methods concern laser fs 3D encoding and source separation for machine-readable identification, moiré and `guilloche' engraving for visual verification and watermarking. Machine-readable travel documents are well-suited examples introducing the second group of methods which are related to cryptography. Used in passports for data authentication and identification (of people), cryptography provides some powerful tools. Opto-digital processing allows some efficient implementations described in the papers and promising applications. We would like to thank the reviewers who have contributed to a session of high quality, and the authors for their fine and hard work. We would like to address some special thanks to the invited lecturers, namely Professor Roger Hersch and Dr Isaac Amidror for their survey of moiré methods, Prof. Serge Vaudenay for his survey of existing protocols concerning machine-readable travel documents, and Dr Elisabet Pérez-Cabré for her presentation on optical encryption for multifactor authentication. We also thank Professor Dominique Jeulin, President of the International Society for Stereology, Professor Michel Jourlin, President of the organizing committee of ICSXII, for their help and advice, and Mr Graham Douglas, the Publisher of Journal of Physics: Conference Series at IOP Publishing, for his efficiency. We hope that this collection of papers will be useful as a tool to further

  12. [Testing method research for key performance indicator of imaging acousto-optic tunable filter (AOTF)].

    Science.gov (United States)

    Hu, Shan-Zhou; Chen, Fen-Fei; Zeng, Li-Bo; Wu, Qiong-Shui

    2013-01-01

    Imaging AOTF is an important optical filter component for new spectral imaging instruments developed in recent years. The principle of imaging AOTF component was demonstrated, and a set of testing methods for some key performances were studied, such as diffraction efficiency, wavelength shift with temperature, homogeneity in space for diffraction efficiency, imaging shift, etc.

  13. Digital images segmentation: a state of art of the different methods ...

    African Journals Online (AJOL)

    An image is a planar representation of a scene or a 3 D object. The primary information associated to each point of the image is transcribed in grey level or in colour. Image analysis is the set of methods which permits the extraction of pertinent information from the image according to the concerned application, to treat them ...

  14. The Study of Image Processing Method for AIDS PA Test

    International Nuclear Information System (INIS)

    Zhang, H J; Wang, Q G

    2006-01-01

    At present, the main test technique of AIDS is PA in China. Because the judgment of PA test image is still depending on operator, the error ration is high. To resolve this problem, we present a new technique of image processing, which first process many samples and get the data including coordinate of center and the rang of kinds images; then we can segment the image with the data; at last, the result is exported after data was judgment. This technique is simple and veracious; and it also turns out to be suitable for the processing and analyzing of other infectious diseases' PA test image

  15. Optical Methods and Instrumentation in Brain Imaging and Therapy

    CERN Document Server

    2013-01-01

    This book provides a comprehensive up-to-date review of optical approaches used in brain imaging and therapy. It covers a variety of imaging techniques including diffuse optical imaging, laser speckle imaging, photoacoustic imaging and optical coherence tomography. A number of laser-based therapeutic approaches are reviewed, including photodynamic therapy, fluorescence guided resection and photothermal therapy. Fundamental principles and instrumentation are discussed for each imaging and therapeutic technique. Represents the first publication dedicated solely to optical diagnostics and therapeutics in the brain Provides a comprehensive review of the principles of each imaging/therapeutic modality Reviews the latest advances in instrumentation for optical diagnostics in the brain Discusses new optical-based therapeutic approaches for brain diseases

  16. A Review of Imaging Methods for Prostate Cancer Detection

    Directory of Open Access Journals (Sweden)

    Saradwata Sarkar

    2016-01-01

    Full Text Available Imaging is playing an increasingly important role in the detection of prostate cancer (PCa. This review summarizes the key imaging modalities–multiparametric ultrasound (US, multiparametric magnetic resonance imaging (MRI, MRI-US fusion imaging, and positron emission tomography (PET imaging–-used in the diagnosis and localization of PCa. Emphasis is laid on the biological and functional characteristics of tumors that rationalize the use of a specific imaging technique. Changes to anatomical architecture of tissue can be detected by anatomical grayscale US and T2-weighted MRI. Tumors are known to progress through angiogenesis–-a fact exploited by Doppler and contrast-enhanced US and dynamic contrast-enhanced MRI. The increased cellular density of tumors is targeted by elastography and diffusion-weighted MRI. PET imaging employs several different radionuclides to target the metabolic and cellular activities during tumor growth. Results from studies using these various imaging techniques are discussed and compared.

  17. Extended morphological processing: a practical method for automatic spot detection of biological markers from microscopic images.

    Science.gov (United States)

    Kimori, Yoshitaka; Baba, Norio; Morone, Nobuhiro

    2010-07-08

    A reliable extraction technique for resolving multiple spots in light or electron microscopic images is essential in investigations of the spatial distribution and dynamics of specific proteins inside cells and tissues. Currently, automatic spot extraction and characterization in complex microscopic images poses many challenges to conventional image processing methods. A new method to extract closely located, small target spots from biological images is proposed. This method starts with a simple but practical operation based on the extended morphological top-hat transformation to subtract an uneven background. The core of our novel approach is the following: first, the original image is rotated in an arbitrary direction and each rotated image is opened with a single straight line-segment structuring element. Second, the opened images are unified and then subtracted from the original image. To evaluate these procedures, model images of simulated spots with closely located targets were created and the efficacy of our method was compared to that of conventional morphological filtering methods. The results showed the better performance of our method. The spots of real microscope images can be quantified to confirm that the method is applicable in a given practice. Our method achieved effective spot extraction under various image conditions, including aggregated target spots, poor signal-to-noise ratio, and large variations in the background intensity. Furthermore, it has no restrictions with respect to the shape of the extracted spots. The features of our method allow its broad application in biological and biomedical image information analysis.

  18. A New Pixels Flipping Method for Huge Watermarking Capacity of the Invoice Font Image

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-01-01

    Full Text Available Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  19. A new pixels flipping method for huge watermarking capacity of the invoice font image.

    Science.gov (United States)

    Li, Li; Hou, Qingzheng; Lu, Jianfeng; Xu, Qishuai; Dai, Junping; Mao, Xiaoyang; Chang, Chin-Chen

    2014-01-01

    Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  20. Myocardial perfusion magnetic resonance imaging using sliding-window conjugate-gradient HYPR methods in canine with stenotic coronary arteries.

    Science.gov (United States)

    Ge, Lan; Kino, Aya; Lee, Daniel; Dharmakumar, Rohan; Carr, James C; Li, Debiao

    2010-01-01

    First-pass perfusion magnetic resonance imaging (MRI) is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, signal-to-noise ratio (SNR), and cardiac motion-related image artifacts. A combination of sliding window and conjugate-gradient HighlY constrained back-PRojection reconstruction (SW-CG-HYPR) method has been proposed in healthy volunteer studies to reduce the acquisition window for each slice while maintaining the temporal resolution of 1 frame per heartbeat in myocardial perfusion MRI. This method allows for improved spatial coverage, resolution, and SNR. In this study, we use a controlled animal model to test whether the myocardial territory supplied by a stenotic coronary artery can be detected accurately by SW-CG-HYPR perfusion method under pharmacological stress. Results from 6 mongrel dogs (15-25 kg) studies demonstrate the feasibility of SW-CG-HYPR to detect regional perfusion defects. Using this method, the acquisition time per cardiac cycle was reduced by a factor of 4, and the spatial coverage was increased from 2 to 3 slices to 6 slices as compared with the conventional techniques including both turbo-Fast Low Angle Short (FLASH) and echoplanar imaging (EPI). The SNR of the healthy myocardium at peak enhancement with SW-CG-HYPR (12.68 ± 2.46) is significantly higher (P < 0.01) than the turbo-FLASH (8.65 ± 1.93) and EPI (5.48 ± 1.24). The spatial resolution of SW-CG-HYPR images is 1.2 × 1.2 × 8.0 mm, which is better than the turbo-FLASH (1.8 × 1.8 × 8.0 mm) and EPI (2.0 × 1.8 × 8.0 mm). Sliding-window CG-HYPR is a promising technique for myocardial perfusion MRI. This technique provides higher image quality with respect to significantly improved SNR and spatial resolution of the myocardial perfusion images, which might improve myocardial perfusion imaging in a clinical setting.