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Sample records for analyzer-based imaging technique

  1. Development and application of the analyzer-based imaging technique with hard synchrotron radiation

    International Nuclear Information System (INIS)

    Coan, P.

    2006-07-01

    The objective of this thesis is twofold: from one side the application of the analyser-based X-ray phase contrast imaging to study cartilage, bone and bone implants using ESRF synchrotron radiation sources and on the other to contribute to the development of the phase contrast techniques from the theoretical and experimental point of view. Several human samples have been studied in vitro using the analyser based imaging (ABI) technique. Examination included projection and computed tomography imaging and 3-dimensional volume rendering of hip, big toe and ankle articular joints. X-ray ABI images have been critically compared with those obtained with conventional techniques, including radiography, computed tomography, ultrasound, magnetic resonance and histology, the latter taken as gold standard. Results show that only ABI imaging was able to either visualize or correctly estimate the early pathological status of the cartilage. The status of the bone ingrowth in sheep implants have also been examined in vitro: ABI images permitted to correctly distinguish between good and incomplete bone healing. Pioneering in-vivo ABI on guinea pigs were also successfully performed, confirming the possible use of the technique to follow up the progression of joint diseases, the bone/metal ingrowth and the efficacy of drugs treatments. As part of the development of the phase contrast techniques, two objectives have been reached. First, it has been experimentally demonstrated for the first time that the ABI and the propagation based imaging (PBI) can be combined to create images with original features (hybrid imaging, HI). Secondly, it has been proposed and experimentally tested a new simplified set-up capable to produce images with properties similar to those obtained with the ABI technique or HI. Finally, both the ABI and the HI have been theoretically studied with an innovative, wave-based simulation program, which was able to correctly reproduce experimental results. (author)

  2. Analyzer-based imaging technique in tomography of cartilage and metal implants: A study at the ESRF

    International Nuclear Information System (INIS)

    Coan, Paola; Mollenhauer, Juergen; Wagner, Andreas; Muehleman, Carol; Bravin, Alberto

    2008-01-01

    Monitoring the progression of osteoarthritis (OA) and the effects of therapy during clinical trials is still a challenge for present clinical imaging techniques since they present intrinsic limitations and can be sensitive only in case of advanced OA stages. In very severe cases, partial or complete joint replacement surgery is the only solution for reducing pain and restoring the joint functions. Poor imaging quality in practically all medical imaging technologies with respect to joint surfaces and to metal implant imaging calls for the development of new techniques that are sensitive to stages preceding the point of irreversible damage of the cartilage tissue. In this scenario, X-ray phase contrast modalities could play an important role since they can provide improved contrast compared to conventional absorption radiography, with a similar or even reduced tissue radiation dose. In this study, the analyzer-based imaging (ABI), a technique sensitive to the X-ray refraction and permitting a high scatter rejection, has been successfully applied in vitro on excised human synovial joints and sheep implants. Pathological and healthy joints as well as metal implants have been imaged in projection and computed tomography ABI mode at high resolution and clinically compatible doses (<10 mGy). Volume rendering and segmentation permitted visualization of the cartilage from volumetric CT-scans. The results demonstrate that ABI can provide an unequivocal non-invasive diagnosis of the state of disease of the joint and be considered a new tool in orthopaedic research

  3. An electron density measurement using an analyzer based imaging system

    International Nuclear Information System (INIS)

    Bewer, Brian

    2011-01-01

    Using a monochromatic X-ray beam from a synchrotron source the electron density of a homogeneous target was determined by measuring the refraction that occurs at the air-target interface for a known angle of incidence. The angle of deviation that these X-rays undergo at the transition between materials is micro-radian to submicro-radian in scale. Existing analyzer based imaging systems are designed to measure submicro-radian angle changes and commonly use monochromatic hard X-ray beams generated from synchrotron sources. A preliminary experiment using the analyzer based imaging apparatus at the Canadian Light Source Biomedical Imaging and Therapy beamline and a half cylinder shaped plastic target will be presented. By measuring the angle of deviation of the photon beam at several discrete angular positions of the target the electron density of the target material was determined.

  4. Noise and analyzer-crystal angular position analysis for analyzer-based phase-contrast imaging

    International Nuclear Information System (INIS)

    Majidi, Keivan; Brankov, Jovan G; Li, Jun; Muehleman, Carol

    2014-01-01

    The analyzer-based phase-contrast x-ray imaging (ABI) method is emerging as a potential alternative to conventional radiography. Like many of the modern imaging techniques, ABI is a computed imaging method (meaning that images are calculated from raw data). ABI can simultaneously generate a number of planar parametric images containing information about absorption, refraction, and scattering properties of an object. These images are estimated from raw data acquired by measuring (sampling) the angular intensity profile of the x-ray beam passed through the object at different angular positions of the analyzer crystal. The noise in the estimated ABI parametric images depends upon imaging conditions like the source intensity (flux), measurements angular positions, object properties, and the estimation method. In this paper, we use the Cramér–Rao lower bound (CRLB) to quantify the noise properties in parametric images and to investigate the effect of source intensity, different analyzer-crystal angular positions and object properties on this bound, assuming a fixed radiation dose delivered to an object. The CRLB is the minimum bound for the variance of an unbiased estimator and defines the best noise performance that one can obtain regardless of which estimation method is used to estimate ABI parametric images. The main result of this paper is that the variance (hence the noise) in parametric images is directly proportional to the source intensity and only a limited number of analyzer-crystal angular measurements (eleven for uniform and three for optimal non-uniform) are required to get the best parametric images. The following angular measurements only spread the total dose to the measurements without improving or worsening CRLB, but the added measurements may improve parametric images by reducing estimation bias. Next, using CRLB we evaluate the multiple-image radiography, diffraction enhanced imaging and scatter diffraction enhanced imaging estimation techniques

  5. Analyzer-based imaging of spinal fusion in an animal model

    International Nuclear Information System (INIS)

    Kelly, M E; Beavis, R C; Allen, L A; Fiorella, David; Schueltke, E; Juurlink, B H; Chapman, L D; Zhong, Z

    2008-01-01

    Analyzer-based imaging (ABI) utilizes synchrotron radiation sources to create collimated monochromatic x-rays. In addition to x-ray absorption, this technique uses refraction and scatter rejection to create images. ABI provides dramatically improved contrast over standard imaging techniques. Twenty-one adult male Wistar rats were divided into four experimental groups to undergo the following interventions: (1) non-injured control, (2) decortication alone, (3) decortication with iliac crest bone grafting and (4) decortication with iliac crest bone grafting and interspinous wiring. Surgical procedures were performed at the L5-6 level. Animals were killed at 2, 4 and 6 weeks after the intervention and the spine muscle blocks were excised. Specimens were assessed for the presence of fusion by (1) manual testing, (2) conventional absorption radiography and (3) ABI. ABI showed no evidence of bone fusion in groups 1 and 2 and showed solid or possibly solid fusion in subjects from groups 3 and 4 at 6 weeks. Metal artifacts were not present in any of the ABI images. Conventional absorption radiographs did not provide diagnostic quality imaging of either the graft material or fusion masses in any of the specimens in any of the groups. Synchrotron-based ABI represents a novel imaging technique which can be used to assess spinal fusion in a small animal model. ABI produces superior image quality when compared to conventional radiographs

  6. In vivo x-ray phase contrast analyzer-based imaging for longitudinal osteoarthritis studies in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Coan, Paola [Faculty of Medicine and Institute of Clinical Radiology, Ludwig-Maximilians University, Munich (Germany); Wagner, Andreas; Mollenhauer, Juergen [Department of Orthopaedics of the University of Jena, Rudolf-Elle-Hospital Eisenberg (Germany); Bravin, Alberto; Diemoz, Paul C; Keyrilaeinen, Jani, E-mail: Paola.Coan@physik.uni-muenchen.d [European Synchrotron Radiation Facility (ESRF), Grenoble (France)

    2010-12-21

    Over the last two decades phase contrast x-ray imaging techniques have been extensively studied for applications in the biomedical field. Published results demonstrate the high capability of these imaging modalities of improving the image contrast of biological samples with respect to standard absorption-based radiography and routinely used clinical imaging techniques. A clear depiction of the anatomic structures and a more accurate disease diagnosis may be provided by using radiation doses comparable to or lower than those used in current clinical methods. In the literature many works show images of phantoms and excised biological samples proving the high sensitivity of the phase contrast imaging methods for in vitro investigations. In this scenario, the applications of the so-called analyzer-based x-ray imaging (ABI) phase contrast technique are particularly noteworthy. The objective of this work is to demonstrate the feasibility of in vivo x-ray ABI phase contrast imaging for biomedical applications and in particular with respect to joint anatomic depiction and osteoarthritis detection. ABI in planar and tomographic modes was performed in vivo on articular joints of guinea pigs in order to investigate the animals with respect to osteoarthritis by using highly monochromatic x-rays of 52 keV and a low noise detector with a pixel size of 47 x 47 {mu}m{sup 2}. Images give strong evidence of the ability of ABI in depicting both anatomic structures in complex systems as living organisms and all known signs of osteoarthritis with high contrast, high spatial resolution and with an acceptable radiation dose. This paper presents the first proof of principle study of in vivo application of ABI. The technical challenges encountered when imaging an animal in vivo are discussed. This experimental study is an important step toward the study of clinical applications of phase contrast x-ray imaging techniques.

  7. Analyzer-based phase-contrast imaging system using a micro focus x-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wei [BME Department, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Majidi, Keivan; Brankov, Jovan G., E-mail: brankov@iit.edu [ECE Department, Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

    2014-08-15

    Here we describe a new in-laboratory analyzer based phase contrast-imaging (ABI) instrument using a conventional X-ray tube source (CXS) aimed at bio-medical imaging applications. Phase contrast-imaging allows visualization of soft tissue details usually obscured in conventional X-ray imaging. The ABI system design and major features are described in detail. The key advantage of the presented system, over the few existing CXS ABI systems, is that it does not require high precision components, i.e., CXS, X-ray detector, and electro-mechanical components. To overcome a main problem introduced by these components, identified as temperature stability, the system components are kept at a constant temperature inside of three enclosures, thus minimizing the electrical and mechanical thermal drifts. This is achieved by using thermoelectric (Peltier) cooling/heating modules that are easy to control precisely. For CXS we utilized a microfocus X-ray source with tungsten (W) anode material. In addition the proposed system eliminates tungsten's multiple spectral lines by selecting monochromator crystal size appropriately therefore eliminating need for the costly mismatched, two-crystal monochromator. The system imaging was fine-tuned for tungsten Kα{sub 1} line with the energy of 59.3 keV since it has been shown to be of great clinical significance by a number of researchers at synchrotron facilities. In this way a laboratory system that can be used for evaluating and quantifying tissue properties, initially explored at synchrotron facilities, would be of great interest to a larger research community. To demonstrate the imaging capability of our instrument we use a chicken thigh tissue sample.

  8. Analyzer-based phase-contrast imaging system using a micro focus X-ray source.

    Science.gov (United States)

    Zhou, Wei; Majidi, Keivan; Brankov, Jovan G

    2014-08-01

    Here we describe a new in-laboratory analyzer based phase contrast-imaging (ABI) instrument using a conventional X-ray tube source (CXS) aimed at bio-medical imaging applications. Phase contrast-imaging allows visualization of soft tissue details usually obscured in conventional X-ray imaging. The ABI system design and major features are described in detail. The key advantage of the presented system, over the few existing CXS ABI systems, is that it does not require high precision components, i.e., CXS, X-ray detector, and electro-mechanical components. To overcome a main problem introduced by these components, identified as temperature stability, the system components are kept at a constant temperature inside of three enclosures, thus minimizing the electrical and mechanical thermal drifts. This is achieved by using thermoelectric (Peltier) cooling/heating modules that are easy to control precisely. For CXS we utilized a microfocus X-ray source with tungsten (W) anode material. In addition the proposed system eliminates tungsten's multiple spectral lines by selecting monochromator crystal size appropriately therefore eliminating need for the costly mismatched, two-crystal monochromator. The system imaging was fine-tuned for tungsten Kα1 line with the energy of 59.3 keV since it has been shown to be of great clinical significance by a number of researchers at synchrotron facilities. In this way a laboratory system that can be used for evaluating and quantifying tissue properties, initially explored at synchrotron facilities, would be of great interest to a larger research community. To demonstrate the imaging capability of our instrument we use a chicken thigh tissue sample.

  9. Development and application of the analyzer-based imaging technique with hard synchrotron radiation; Developpement et application d'une technique d'imagerie par rayonnement synchrotron basee sur l'utilisation d'un cristal analyseur

    Energy Technology Data Exchange (ETDEWEB)

    Coan, P

    2006-07-15

    The objective of this thesis is twofold: from one side the application of the analyser-based X-ray phase contrast imaging to study cartilage, bone and bone implants using ESRF synchrotron radiation sources and on the other to contribute to the development of the phase contrast techniques from the theoretical and experimental point of view. Several human samples have been studied in vitro using the analyser based imaging (ABI) technique. Examination included projection and computed tomography imaging and 3-dimensional volume rendering of hip, big toe and ankle articular joints. X-ray ABI images have been critically compared with those obtained with conventional techniques, including radiography, computed tomography, ultrasound, magnetic resonance and histology, the latter taken as gold standard. Results show that only ABI imaging was able to either visualize or correctly estimate the early pathological status of the cartilage. The status of the bone ingrowth in sheep implants have also been examined in vitro: ABI images permitted to correctly distinguish between good and incomplete bone healing. Pioneering in-vivo ABI on guinea pigs were also successfully performed, confirming the possible use of the technique to follow up the progression of joint diseases, the bone/metal ingrowth and the efficacy of drugs treatments. As part of the development of the phase contrast techniques, two objectives have been reached. First, it has been experimentally demonstrated for the first time that the ABI and the propagation based imaging (PBI) can be combined to create images with original features (hybrid imaging, HI). Secondly, it has been proposed and experimentally tested a new simplified set-up capable to produce images with properties similar to those obtained with the ABI technique or HI. Finally, both the ABI and the HI have been theoretically studied with an innovative, wave-based simulation program, which was able to correctly reproduce experimental results. (author)

  10. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between...... various requirements to be fulfilled in the design of an imaging system for breast cancer detection and some strategies to overcome these limitations....

  11. Multimodality imaging techniques.

    Science.gov (United States)

    Martí-Bonmatí, Luis; Sopena, Ramón; Bartumeus, Paula; Sopena, Pablo

    2010-01-01

    In multimodality imaging, the need to combine morphofunctional information can be approached by either acquiring images at different times (asynchronous), and fused them through digital image manipulation techniques or simultaneously acquiring images (synchronous) and merging them automatically. The asynchronous post-processing solution presents various constraints, mainly conditioned by the different positioning of the patient in the two scans acquired at different times in separated machines. The best solution to achieve consistency in time and space is obtained by the synchronous image acquisition. There are many multimodal technologies in molecular imaging. In this review we will focus on those multimodality image techniques more commonly used in the field of diagnostic imaging (SPECT-CT, PET-CT) and new developments (as PET-MR). The technological innovations and development of new tracers and smart probes are the main key points that will condition multimodality image and diagnostic imaging professionals' future. Although SPECT-CT and PET-CT are standard in most clinical scenarios, MR imaging has some advantages, providing excellent soft-tissue contrast and multidimensional functional, structural and morphological information. The next frontier is to develop efficient detectors and electronics systems capable of detecting two modality signals at the same time. Not only PET-MR but also MR-US or optic-PET will be introduced in clinical scenarios. Even more, MR diffusion-weighted, pharmacokinetic imaging, spectroscopy or functional BOLD imaging will merge with PET tracers to further increase molecular imaging as a relevant medical discipline. Multimodality imaging techniques will play a leading role in relevant clinical applications. The development of new diagnostic imaging research areas, mainly in the field of oncology, cardiology and neuropsychiatry, will impact the way medicine is performed today. Both clinical and experimental multimodality studies, in

  12. Nonmammographic breast imaging techniques.

    Science.gov (United States)

    Heywang-Köbrunner, S H

    1992-10-01

    Significant progress in early detection of malignancy has been achieved by the improvement of mammographic technique, the introduction of quality control, the demonstration of benefits from screening, and appropriate application of supplementary methods such as ultrasound, cytology, and stereotaxis. Certain problems in breast imaging, however, are still unsolved. These include early detection and exclusion of malignancy without microcalcifications in mammographically dense tissue (particularly in younger women), the still-limited accuracy of mammographic signs, and the management of diagnostic problems after surgery, radiation therapy, or silicone implants. Therefore, research is needed to further improve diagnostic capabilities. The research can be subdivided into different approaches: 1) further development of the mammographic technique (digital luminescence radiography); 2) evaluation of techniques that image other physical tissue properties (sonography, thermography, trans-illumination, CT, non-contrast-enhanced MR imaging, biomagnetism, biostereometry, and ductoscopy); 3) investigation of techniques that image metabolic changes (MR spectroscopy, positron-emission tomography) or metabolism-induced differences in perfusion or vascularity (Doppler ultrasound, contrast-enhanced MR imaging); and 4) development of techniques that attempt tissue diagnosis using monoclonal antibodies. Among these techniques, digital luminescence radiography and contrast-enhanced MR imaging are the most developed and the most promising. They are at the threshold of becoming clinically important. Doppler ultrasound could be useful for certain indications. Whereas MR spectroscopy, positron-emission tomography, the search for appropriate antibodies, and possibly transillumination, ductoscopy, and biomagnetism offer interesting new aspects for research, the value of CT, thermography, and biostereometry is not yet established.

  13. Imaging Techniques in Conservation

    OpenAIRE

    Payne, Emma Marie

    2013-01-01

    New imaging techniques are increasingly being used within cultural heritage. This paper explores potential uses of such technologies within conservation and implications of their use on object preservation and accessibility. Study of their effects on objects is crucial because their employment is becoming irreplaceable; for example, polynomial texture mapping (PTM) has revealed previously undetectable surface features. In such cases, it is necessary to continue to use the technique to monitor...

  14. Imaging Techniques in Conservation

    Directory of Open Access Journals (Sweden)

    Emma Marie Payne

    2013-02-01

    Full Text Available New imaging techniques are increasingly being used within cultural heritage. This paper explores potential uses of such technologies within conservation and implications of their use on object preservation and accessibility. Study of their effects on objects is crucial because their employment is becoming irreplaceable; for example, polynomial texture mapping (PTM has revealed previously undetectable surface features. In such cases, it is necessary to continue to use the technique to monitor object condition. 3D laser scanning, PTM, and CT scanning are investigated. Case studies are explored to investigate their current role in cultural heritage. The appropriateness of this role and whether it should be expanded is addressed by analysing advantages and disadvantages of the techniques, their feasibility, and risks caused to object preservation and accessibility. The results indicate that the technologies present some advantages over standard digital photography; PTM in particular is found to be an extremely useful, affordable technique. A more established role within conservation, especially for condition assessments, could be worthwhile. Use of the imaging techniques to create models for exhibition can also be advantageous; however, care must be taken to ensure that such models are used to enhance accessibility to original objects and not to replace them.

  15. Imaging Techniques and Indications.

    Science.gov (United States)

    Mahoney, James M

    2017-04-01

    This article evaluates the utility of radiography, ultrasonography, and MRI in diagnosing Achilles tendon injuries. It reviews the pertinent anatomy of the Achilles and associated structures, and signs of disorder with each imaging technique. The economics of use ultrasonography and MRI are discussed. They should serve as complementary diagnostic tools, with ultrasonography the first choice because of its ease of use, ability to view dynamic function, and cost. However, clinical examination is often best for diagnosis; MRI and ultrasonography often should be considered only when the diagnosis is confounding or a patient does not respond to recommended conservative care. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Simultaneous multislice (SMS) imaging techniques

    NARCIS (Netherlands)

    Barth, M.; Breuer, F.; Koopmans, P.J.; Norris, David Gordon; Poser, B.A.

    2016-01-01

    Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in-plane parallel imaging this can have

  17. Nuclear medicine imaging techniques

    NARCIS (Netherlands)

    Noordzij, Walter; Glaudemans, Andor W.J.M.

    2015-01-01

    Nuclear medicine is a rapidly developing field which focuses on the imaging of physiological processes and the evaluation of treatment of specific diseases. It involves the use of radiopharmaceuticals for both purposes. Different radiopharmaceuticals have different kinetics and can therefore be used

  18. Review of advanced imaging techniques

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2012-01-01

    Full Text Available Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images ("optical biopsies" at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy. This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques.

  19. Advanced imaging techniques

    International Nuclear Information System (INIS)

    Young, I.R.

    1987-01-01

    This chapter has been divided into three main sections. The first of these is concerned with things that are orientated to a degree towards novel hardware. This is obviously true of coils - which are essential for high performance in NMR imaging. The section reviews surface coils, and their applications, and closely-coupled coils (although it does not consider resonators, which are the best whole region coil design in high field head and body imaging). Closely-coupled coils are only described cursorily, however, since they, too, can be regarded as approaching a routine solution. The other 'hardware' heading is gating - which is clearly a fair assessment in as far as cardiac gating is concerned, although respiratory gating methods make major demands on software as well as needing appropriate transducers. The second major section is concerned with reconstruction methods. This begins with systems which depend on phase mapping and display (things like flow and field homogeneity and susceptibility imaging). Finally, there is a review of some of the more specialist and unusual uses of sequences to manipulate tissue contrast, and produce effects designed to be applied to solving particular clinical problems

  20. Simultaneous multislice (SMS) imaging techniques.

    Science.gov (United States)

    Barth, Markus; Breuer, Felix; Koopmans, Peter J; Norris, David G; Poser, Benedikt A

    2016-01-01

    Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in-plane parallel imaging this can have only a marginal intrinsic signal-to-noise ratio penalty, and the full acceleration is attainable at fixed echo time, as is required for many echo planar imaging applications. Furthermore, for some implementations SMS techniques can reduce radiofrequency (RF) power deposition. In this review the current state of the art of SMS imaging is presented. In the Introduction, a historical overview is given of the history of SMS excitation in MRI. The following section on RF pulses gives both the theoretical background and practical application. The section on encoding and reconstruction shows how the collapsed multislice images can be disentangled by means of the transmitter pulse phase, gradient pulses, and most importantly using multichannel receiver coils. The relationship between classic parallel imaging techniques and SMS reconstruction methods is explored. The subsequent section describes the practical implementation, including the acquisition of reference data, and slice cross-talk. Published applications of SMS imaging are then reviewed, and the article concludes with an outlook and perspective of SMS imaging. © 2015 Wiley Periodicals, Inc.

  1. Automated medical image segmentation techniques

    Directory of Open Access Journals (Sweden)

    Sharma Neeraj

    2010-01-01

    Full Text Available Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT and Magnetic resonance (MR imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  2. Developments in medical imaging techniques

    International Nuclear Information System (INIS)

    Kramer, Cornelis

    1979-01-01

    A review of the developments in medical imaging in the past 25 years shows a strong increase in the number of physical methods which have become available for obtaining images of diagnostic value. It is shown that despite this proliferation of methods the equipment used for obtaining the images can be based on a common structure. Also the resulting images can be characterized by a few relevant parameters which indicate their information content. On the basis of this common architecture a study is made of the potential capabilities of the large number of medical imaging techniques available now and in the future. Also the requirements and possibilities for handling the images obtained and for controlling the diagnostic systems are investigated [fr

  3. EDITORIAL: Imaging systems and techniques Imaging systems and techniques

    Science.gov (United States)

    Yang, Wuqiang; Giakos, George; Nikita, Konstantina; Pastorino, Matteo; Karras, Dimitrios

    2009-10-01

    The papers in this special issue focus on providing the state-of-the-art approaches and solutions to some of the most challenging imaging areas, such as the design, development, evaluation and applications of imaging systems, measuring techniques, image processing algorithms and instrumentation, with an ultimate aim of enhancing the measurement accuracy and image quality. This special issue explores the principles, engineering developments and applications of new imaging systems and techniques, and encourages broad discussion of imaging methodologies, shaping the future and identifying emerging trends. The multi-faceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment and technological evolution. There is an urgent need to address new problems, which tend to be either static but complex, or dynamic, e.g. rapidly evolving with time, with many unknowns, and to propose innovative solutions. For instance, the battles against cancer and terror, monitoring of space resources and enhanced awareness, management of natural resources and environmental monitoring are some of the areas that need to be addressed. The complexity of the involved imaging scenarios and demanding design parameters, e.g. speed, signal-to-noise ratio (SNR), specificity, contrast, spatial resolution, scatter rejection, complex background and harsh environments, necessitate the development of a multi-functional, scalable and efficient imaging suite of sensors, solutions driven by innovation, and operation on diverse detection and imaging principles. Efficient medical imaging techniques capable of providing physiological information at the molecular level present another important research area. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, and using high-resolution, high-selectivity nano-imaging methods, quantum dots, nanoparticles, biomarkers, nanostructures, nanosensors, micro-array imaging chips

  4. Radar rainfall image repair techniques

    Directory of Open Access Journals (Sweden)

    Stephen M. Wesson

    2004-01-01

    Full Text Available There are various quality problems associated with radar rainfall data viewed in images that include ground clutter, beam blocking and anomalous propagation, to name a few. To obtain the best rainfall estimate possible, techniques for removing ground clutter (non-meteorological echoes that influence radar data quality on 2-D radar rainfall image data sets are presented here. These techniques concentrate on repairing the images in both a computationally fast and accurate manner, and are nearest neighbour techniques of two sub-types: Individual Target and Border Tracing. The contaminated data is estimated through Kriging, considered the optimal technique for the spatial interpolation of Gaussian data, where the 'screening effect' that occurs with the Kriging weighting distribution around target points is exploited to ensure computational efficiency. Matrix rank reduction techniques in combination with Singular Value Decomposition (SVD are also suggested for finding an efficient solution to the Kriging Equations which can cope with near singular systems. Rainfall estimation at ground level from radar rainfall volume scan data is of interest and importance in earth bound applications such as hydrology and agriculture. As an extension of the above, Ordinary Kriging is applied to three-dimensional radar rainfall data to estimate rainfall rate at ground level. Keywords: ground clutter, data infilling, Ordinary Kriging, nearest neighbours, Singular Value Decomposition, border tracing, computation time, ground level rainfall estimation

  5. Raman Imaging Techniques and Applications

    CERN Document Server

    2012-01-01

    Raman imaging has long been used to probe the chemical nature of a sample, providing information on molecular orientation, symmetry and structure with sub-micron spatial resolution. Recent technical developments have pushed the limits of micro-Raman microscopy, enabling the acquisition of Raman spectra with unprecedented speed, and opening a pathway to fast chemical imaging for many applications from material science and semiconductors to pharmaceutical drug development and cell biology, and even art and forensic science. The promise of tip-enhanced raman spectroscopy (TERS) and near-field techniques is pushing the envelope even further by breaking the limit of diffraction and enabling nano-Raman microscopy.

  6. Tooling Techniques Enhance Medical Imaging

    Science.gov (United States)

    2012-01-01

    mission. The manufacturing techniques developed to create the components have yielded innovations advancing medical imaging, transportation security, and even energy efficiency.

  7. MR imaging techniques in neuroradiology

    International Nuclear Information System (INIS)

    Sasaki, Makoto

    1999-01-01

    Recently developed MR imaging techniques, including fast spin echo, fluid-attenuated inversion recovery, T 1 -weighted fast gradient echo, and Gd-enhanced 3D MR angiography, are reviewed. In fast spin echo sequences, blur, pseudo edge enhancement, edge enhancing effect, and ghost may appear depending on T 2 -weighting and discreteness in the k-space. Contrast modifications, such as signal attenuation by off-resonance RF pulses, bright fat on late echoes, low sensitivity to diffusion-mediated susceptibility effects, and delay of the T 1 recovery, are also discussed. Fluid-attenuated inversion recovery is a ''moderately'' T 2 -weighted sequence with suppression of the CSF signal. With a relatively short repetition time, signal suppression is remarkable in the lesions with relatively long T 1 values, so that a very long repetition time more than 10 s is recommended. On T 1 -weighted spoiled fast gradient-echo sequences, the enhancement effect of parenchymal lesions by gadopentetate dimeglumine is insufficient compared with a T 1 -weighted spin echo sequence. IR-prepared fast gradient-echo sequences, such as MP-RAGE, may solve this problem to some degree, although their T 1 magnetization is difficult to estimate. On Gd-enhanced 3D MR angiography, k-space order, spatial resolution, temporal resolution, and background suppression are crucial to obtain sufficient images. They should be optimized for accurate evaluation of internal carotid artery lesions according to AHA guidelines. (author)

  8. Image reconstruction technique for neutron penumbra imaging

    International Nuclear Information System (INIS)

    Liu Dongjian

    2006-01-01

    The principle of the neutron penumbra imaging was introduced, and the effect factors of the resolution of the imaging system were analyzed. The neutron penumbra imaging process was simulated with MCNP software. The coded image of one point source on the imaging principal axis and that of two point sources off the principal axis with and without noise and back-ground were reconstructed by the improved inverse filter and Wiener filter method respectively. The simulation results indicated that the Wiener filter method could restrain noise better. (authors)

  9. Imaging Techniques in Endodontics: An Overview

    Science.gov (United States)

    Deepak, B. S.; Subash, T. S.; Narmatha, V. J.; Anamika, T.; Snehil, T. K.; Nandini, D. B.

    2012-01-01

    This review provides an overview of the relevance of imaging techniques such as, computed tomography, cone beam computed tomography, and ultrasound, to endodontic practice. Many limitations of the conventional radiographic techniques have been overcome by the newer methods. Advantages and disadvantages of various imaging techniques in endodontic practice are also discussed. PMID:22530184

  10. An edge extraction technique for noisy images

    International Nuclear Information System (INIS)

    Cios, K.J.; Sarieh, A.

    1990-01-01

    We present an algorithm for extracting edges from noisy images. Our method uses an unsupervised learning approach for local threshold computation by means of Pearson's method for mixture density identification. We tested the technique by applying it to computer-generated images corrupted with artificial noise and to an actual Thallium-201 heart image and it is shown that the technique has potential use for noisy images

  11. 1.3 Imaging techniques

    International Nuclear Information System (INIS)

    1984-01-01

    The digital processing is described of X-ray images and the replacement of film with xerography and ionography. Advantages of the image digital processing are better resolution of the degree of attenuation of X-ray radiation, possibility of subsequent image processing, a lower radiation load and simplifyied examinations. In xeroradiography the film is replaced by a plate with a sensitive semiconductive layer. The obtained images have better resolution of interfaces of tissue with a different absorption of radiation which is advantageous for evaluation but can in some instances conceal certain details. Ionography provides high quality imao.es with increased resolution. Technical problems now stand in the way of the practical application of this method. (Ha)

  12. Ultra high speed image processing techniques. [electronic packaging techniques

    Science.gov (United States)

    Anthony, T.; Hoeschele, D. F.; Connery, R.; Ehland, J.; Billings, J.

    1981-01-01

    Packaging techniques for ultra high speed image processing were developed. These techniques involve the development of a signal feedthrough technique through LSI/VLSI sapphire substrates. This allows the stacking of LSI/VLSI circuit substrates in a 3 dimensional package with greatly reduced length of interconnecting lines between the LSI/VLSI circuits. The reduced parasitic capacitances results in higher LSI/VLSI computational speeds at significantly reduced power consumption levels.

  13. Recent developments on techniques for differential phase imaging at the medical beamline of ELETTRA

    Science.gov (United States)

    Arfelli, F.; Pelliccia, D.; Cedola, A.; Astolfo, A.; Bukreeva, I.; Cardarelli, P.; Dreossi, D.; Lagomarsino, S.; Longo, R.; Rigon, L.; Sodini, N.; Menk, R. H.

    2013-06-01

    Over the last decade different phase contrast approaches have been exploited at the medical beamline SYRMEP of the synchrotron radiation facility Elettra in Trieste, Italy. In particular special focus has been drawn to analyzer based imaging and the associated imaging theory and processing. Analyzer based Imaging (ABI) and Diffraction Enhanced Imaging (DEI) techniques have been successfully applied in several biomedical applications. Recently it has been suggested to translate the acquired knowledge in this field towards a Thomson Backscattering Source (TBS), which is presently under development at the Frascati National Laboratories of INFN (Istituto Nazionale di Fisica Nucleare) in Rome, Italy. Such source is capable of producing intense and quasi-monochromatic hard X-ray beams. For the technical implementation of biomedical phase imaging at the TBS a grating interferometer for differential phase contrast imaging has been designed and successfully tested at SYRMEP beamline.

  14. Terahertz Imaging Systems With Aperture Synthesis Techniques

    DEFF Research Database (Denmark)

    Krozer, Viktor; Löffler, Torsten; Dall, Jørgen

    2010-01-01

    imaging systems are reviewed in terms of the employed architecture and data processing strategies. Active multichannel measurement method is found to be promising for real-time applications among the various terahertz imaging techniques and is chosen as a basis for the imaging instruments presented......This paper presents the research and development of two terahertz imaging systems based on photonic and electronic principles, respectively. As part of this study, a survey of ongoing research in the field of terahertz imaging is provided focusing on security applications. Existing terahertz...... in this paper. An active system operation allows for a wide dynamic range, which is important for image quality. The described instruments employ a multichannel high-sensitivity heterodyne architecture and aperture filling techniques, with close to real-time image acquisition time. In the case of the photonic...

  15. Techniques for thyroid imaging; Les techniques d`imagerie thyroidienne

    Energy Technology Data Exchange (ETDEWEB)

    Hermans, J.

    1995-12-31

    Advances in imaging techniques has improved our understanding of diseases. The different imaging techniques for visualizing the thyroid parenchyma, including cyto-puncture, sonography, CT-scan, scintigraphy, magnetic resonance imaging, have provided various types of information. Do these techniques really provide the clinician with the answers to his questions. The information provided by the different imaging techniques is presented together with the insufficiencies of each method. Faced with the rising cost of health services, we developed analysis instruments which should help the clinician in a more rational use of diagnostic examinations. The question which most often arises is that of an isolated nodule within a multi-nodular goiter : is it malignant or benign. the analysis of the available techniques shows that cost-effective strategy uses conventional Tc99m or I123 scintigraphy and thallium 201 scintigraphy. With this strategy, the risk of missing a thyroid cancer is approximately 1.75%. With cyto-puncture, this risk is multiplied by a factor of 2.5 reaching 4.5%. (Author). 31 refs., 7 tabs.

  16. Image processing techniques for digital orthophotoquad production

    Science.gov (United States)

    Hood, Joy J.; Ladner, L. J.; Champion, Richard A.

    1989-01-01

    Orthophotographs have long been recognized for their value as supplements or alternatives to standard maps. Recent trends towards digital cartography have resulted in efforts by the US Geological Survey to develop a digital orthophotoquad production system. Digital image files were created by scanning color infrared photographs on a microdensitometer. Rectification techniques were applied to remove tile and relief displacement, thereby creating digital orthophotos. Image mosaicking software was then used to join the rectified images, producing digital orthophotos in quadrangle format.

  17. [New techniques of scintigraphic imaging].

    Science.gov (United States)

    Chatal, J F

    1990-01-01

    The purpose of scintigraphic imaging is not to explore the morphology of an organ (or its abnormalities) but rather its functional and metabolic characteristics. It is thus important that a molecular structure (e.g., a hormonal receptor or an antigen) closely linked to the functional activity of an organ or tissue be targeted on its cell surface. Such diagnostic targeting requires the synthesis and labeling of a radiopharmaceutical substance specific for the receptor or antigen in question. It also requires a detection system adapted to count rates and signal-to-background ratios (generally moderate). The synthesis of new radiopharmaceutical agents, a critical stage for the future of nuclear medicine, is a long and often risky process in which success is difficult to foresee. Radiolabeling must be stable in vitro and in vivo, and the radiopharmaceutical must subsequently retain its capability of recognizing the targeted molecule. In endocrinology, the exemplary achievement in this direction has been the synthesis of 131I-6-iodomethylnorcholesterol and 131I-metaiodobenzylquanidine for functional scintigraphy of the adrenal cortex and medulla. Progress in detection equipment has been marked by the development of monophotonic tomoscintigraphy, using gamma cameras with a revolving head to obtain slices in different spatial planes showing the distribution in the organism of the injected radiopharmaceutical agent.

  18. Ultrasonic Imaging Techniques for Breast Cancer Detection

    Science.gov (United States)

    Goulding, N. R.; Marquez, J. D.; Prewett, E. M.; Claytor, T. N.; Nadler, B. R.

    2008-02-01

    Improving the resolution and specificity of current ultrasonic imaging technology is needed to enhance its relevance to breast cancer detection. A novel ultrasonic imaging reconstruction method is described that exploits classical straight-ray migration. This novel method improves signal processing for better image resolution and uses novel staging hardware options using a pulse-echo approach. A breast phantom with various inclusions is imaged using the classical migration method and is compared to standard computed tomography (CT) scans. These innovative ultrasonic methods incorporate ultrasound data acquisition, beam profile characterization, and image reconstruction. For an ultrasonic frequency of 2.25 MHz, imaged inclusions of approximately 1 cm are resolved and identified. Better resolution is expected with minor modifications. Improved image quality and resolution enables earlier detection and more accurate diagnoses of tumors thus reducing the number of biopsies performed, increasing treatment options, and lowering remission percentages. Using these new techniques the inclusions in the phantom are resolved and compared to the results of standard methods. Refinement of this application using other imaging techniques such as time-reversal mirrors (TRM), synthetic aperture focusing technique (SAFT), decomposition of the time reversal operator (DORT), and factorization methods is also discussed.

  19. Robust document image binarization technique for degraded document images.

    Science.gov (United States)

    Su, Bolan; Lu, Shijian; Tan, Chew Lim

    2013-04-01

    Segmentation of text from badly degraded document images is a very challenging task due to the high inter/intra-variation between the document background and the foreground text of different document images. In this paper, we propose a novel document image binarization technique that addresses these issues by using adaptive image contrast. The adaptive image contrast is a combination of the local image contrast and the local image gradient that is tolerant to text and background variation caused by different types of document degradations. In the proposed technique, an adaptive contrast map is first constructed for an input degraded document image. The contrast map is then binarized and combined with Canny's edge map to identify the text stroke edge pixels. The document text is further segmented by a local threshold that is estimated based on the intensities of detected text stroke edge pixels within a local window. The proposed method is simple, robust, and involves minimum parameter tuning. It has been tested on three public datasets that are used in the recent document image binarization contest (DIBCO) 2009 & 2011 and handwritten-DIBCO 2010 and achieves accuracies of 93.5%, 87.8%, and 92.03%, respectively, that are significantly higher than or close to that of the best-performing methods reported in the three contests. Experiments on the Bickley diary dataset that consists of several challenging bad quality document images also show the superior performance of our proposed method, compared with other techniques.

  20. Interpretation techniques. [image enhancement and pattern recognition

    Science.gov (United States)

    Dragg, J. L.

    1974-01-01

    The image enhancement and geometric correction and registration techniques developed and/or demonstrated on ERTS data are relatively mature and greatly enhance the utility of the data for a large variety of users. Pattern recognition was improved by the use of signature extension, feature extension, and other classification techniques. Many of these techniques need to be developed and generalized to become operationally useful. Advancements in the mass precision processing of ERTS were demonstrated, providing the hope for future earth resources data to be provided in a more readily usable state. Also in evidence is an increasing and healthy interaction between the techniques developers and the user/applications investigators.

  1. A summary of image segmentation techniques

    Science.gov (United States)

    Spirkovska, Lilly

    1993-01-01

    Machine vision systems are often considered to be composed of two subsystems: low-level vision and high-level vision. Low level vision consists primarily of image processing operations performed on the input image to produce another image with more favorable characteristics. These operations may yield images with reduced noise or cause certain features of the image to be emphasized (such as edges). High-level vision includes object recognition and, at the highest level, scene interpretation. The bridge between these two subsystems is the segmentation system. Through segmentation, the enhanced input image is mapped into a description involving regions with common features which can be used by the higher level vision tasks. There is no theory on image segmentation. Instead, image segmentation techniques are basically ad hoc and differ mostly in the way they emphasize one or more of the desired properties of an ideal segmenter and in the way they balance and compromise one desired property against another. These techniques can be categorized in a number of different groups including local vs. global, parallel vs. sequential, contextual vs. noncontextual, interactive vs. automatic. In this paper, we categorize the schemes into three main groups: pixel-based, edge-based, and region-based. Pixel-based segmentation schemes classify pixels based solely on their gray levels. Edge-based schemes first detect local discontinuities (edges) and then use that information to separate the image into regions. Finally, region-based schemes start with a seed pixel (or group of pixels) and then grow or split the seed until the original image is composed of only homogeneous regions. Because there are a number of survey papers available, we will not discuss all segmentation schemes. Rather than a survey, we take the approach of a detailed overview. We focus only on the more common approaches in order to give the reader a flavor for the variety of techniques available yet present enough

  2. Cellular imaging electron tomography and related techniques

    CERN Document Server

    2018-01-01

    This book highlights important techniques for cellular imaging and covers the basics and applications of electron tomography and related techniques. In addition, it considers practical aspects and broadens the technological focus by incorporating techniques that are only now becoming accessible (e.g. block face imaging).  The first part of the book describes the electron microscopy 3D technique available to scientists around the world, allowing them to characterize organelles, cells and tissues. The major emphasis is on new technologies like scanning transmission electron microscopy (STEM) tomography, though the book also reviews some of the more proven technologies like electron tomography. In turn, the second part is dedicated to the reconstruction of data sets, signal improvement and interpretation.

  3. Image processing techniques for remote sensing data

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    interpretation and for processing of scene data for autonomous machine perception. The technique of digital image processing are used for' automatic character/pattern recognition, industrial robots for product assembly and inspection, military recognizance...-Type text/plain; charset=UTF-8 4. IMAGE PROCE:>SINGTOO~IQUE3FOR RmOTE SmSING DATA M. R. RAIirnH KUMAR National Institute of Oceanography, Dona PaUla, Goa-403004. Digital image processing is used for improvement of pictorial information for human...

  4. Performance evaluation of breast image compression techniques

    International Nuclear Information System (INIS)

    Anastassopoulos, G.; Lymberopoulos, D.; Panayiotakis, G.; Bezerianos, A.

    1994-01-01

    Novel diagnosis orienting tele working systems manipulate, store, and process medical data through real time communication - conferencing schemes. One of the most important factors affecting the performance of these systems is image handling. Compression algorithms can be applied to the medical images, in order to minimize : a) the volume of data to be stored in the database, b) the demanded bandwidth from the network, c) the transmission costs, and to minimize the speed of the transmitted data. In this paper an estimation of all the factors of the process that affect the presentation of breast images is made, from the time the images are produced from a modality, till the compressed images are stored, or transmitted in a Broadband network (e.g. B-ISDN). The images used were scanned images of the TOR(MAX) Leeds breast phantom, as well as typical breast images. A comparison of seven compression techniques has been done, based on objective criteria such as Mean Square Error (MSE), resolution, contrast, etc. The user can choose the appropriate compression ratio in order to achieve the desired image quality. (authors)

  5. Retinal Imaging Techniques for Diabetic Retinopathy Screening

    Science.gov (United States)

    Goh, James Kang Hao; Cheung, Carol Y.; Sim, Shaun Sebastian; Tan, Pok Chien; Tan, Gavin Siew Wei; Wong, Tien Yin

    2016-01-01

    Due to the increasing prevalence of diabetes mellitus, demand for diabetic retinopathy (DR) screening platforms is steeply increasing. Early detection and treatment of DR are key public health interventions that can greatly reduce the likelihood of vision loss. Current DR screening programs typically employ retinal fundus photography, which relies on skilled readers for manual DR assessment. However, this is labor-intensive and suffers from inconsistency across sites. Hence, there has been a recent proliferation of automated retinal image analysis software that may potentially alleviate this burden cost-effectively. Furthermore, current screening programs based on 2-dimensional fundus photography do not effectively screen for diabetic macular edema (DME). Optical coherence tomography is becoming increasingly recognized as the reference standard for DME assessment and can potentially provide a cost-effective solution for improving DME detection in large-scale DR screening programs. Current screening techniques are also unable to image the peripheral retina and require pharmacological pupil dilation; ultra-widefield imaging and confocal scanning laser ophthalmoscopy, which address these drawbacks, possess great potential. In this review, we summarize the current DR screening methods using various retinal imaging techniques, and also outline future possibilities. Advances in retinal imaging techniques can potentially transform the management of patients with diabetes, providing savings in health care costs and resources. PMID:26830491

  6. Tablet surface characterisation by various imaging techniques

    DEFF Research Database (Denmark)

    Seitavuopio, Paulus; Rantanen, Jukka; Yliruusi, Jouko

    2003-01-01

    The aim of this study was to characterise tablet surfaces using different imaging and roughness analytical techniques including optical microscopy, scanning electron microscopy (SEM), laser profilometry and atomic force microscopy (AFM). The test materials compressed were potassium chloride (KCl......) and sodium chloride (NaCl). It was found that all methods used suggested that the KCl tablets were smoother than the NaCl tablets and higher compression pressure made the tablets smoother. Imaging methods like optical microscopy and SEM can give useful information about the roughness of the sample surface......, but they do not provide quantitative information about surface roughness. Laser profilometry and AFM on the other hand provide quantitative roughness data from two different scales, laser profilometer from 1 mm and atomic force microscope from 90 microm scale. AFM is a powerful technique but other imaging...

  7. Techniques of noninvasive optical tomographic imaging

    Science.gov (United States)

    Rosen, Joseph; Abookasis, David; Gokhler, Mark

    2006-01-01

    Recently invented methods of optical tomographic imaging through scattering and absorbing media are presented. In one method, the three-dimensional structure of an object hidden between two biological tissues is recovered from many noisy speckle pictures obtained on the output of a multi-channeled optical imaging system. Objects are recovered from many speckled images observed by a digital camera through two stereoscopic microlens arrays. Each microlens in each array generates a speckle image of the object buried between the layers. In the computer each image is Fourier transformed jointly with an image of the speckled point-like source captured under the same conditions. A set of the squared magnitudes of the Fourier-transformed pictures is accumulated to form a single average picture. This final picture is again Fourier transformed, resulting in the three-dimensional reconstruction of the hidden object. In the other method, the effect of spatial longitudinal coherence is used for imaging through an absorbing layer with different thickness, or different index of refraction, along the layer. The technique is based on synthesis of multiple peak spatial degree of coherence. This degree of coherence enables us to scan simultaneously different sample points on different altitudes, and thus decreases the acquisition time. The same multi peak degree of coherence is also used for imaging through the absorbing layer. Our entire experiments are performed with a quasi-monochromatic light source. Therefore problems of dispersion and inhomogeneous absorption are avoided.

  8. Comparative study of image restoration techniques in forensic image processing

    Science.gov (United States)

    Bijhold, Jurrien; Kuijper, Arjan; Westhuis, Jaap-Harm

    1997-02-01

    In this work we investigated the forensic applicability of some state-of-the-art image restoration techniques for digitized video-images and photographs: classical Wiener filtering, constrained maximum entropy, and some variants of constrained minimum total variation. Basic concepts and experimental results are discussed. Because all methods appeared to produce different results, a discussion is given of which method is the most suitable, depending on the image objects that are questioned, prior knowledge and type of blur and noise. Constrained minimum total variation methods produced the best results for test images with simulated noise and blur. In cases where images are the most substantial part of the evidence, constrained maximum entropy might be more suitable, because its theoretical basis predicts a restoration result that shows the most likely pixel values, given all the prior knowledge used during restoration.

  9. In vitro imaging techniques in neurodegenerative diseases.

    Science.gov (United States)

    Långström, Bengt; Andrén, Per E; Lindhe, Orjan; Svedberg, Marie; Hall, Håkan

    2007-01-01

    Neurodegeneration induces various changes in the brain, changes that may be investigated using neuroimaging techniques. The in vivo techniques are useful for the visualization of major changes, and the progressing abnormalities may also be followed longitudinally. However, to study and quantify minor abnormalities, neuroimaging of postmortem brain tissue is used. These in vitro methods are complementary to the in vivo techniques and contribute to the knowledge of pathophysiology and etiology of the neurodegenerative diseases. In vitro radioligand autoradiography has given great insight in the involvement of different neuronal receptor systems in these diseases. Data on the dopamine and cholinergic systems in neurodegeneration are discussed in this review. Also, the amyloid plaques are studied using in vitro radioligand autoradiography. Using one of the newer methods, imaging matrix-assisted laser desorption ionization mass spectrometry, the distribution of a large number of peptides and proteins may be detected in vitro on brain cryosections. In this overview, we describe in vitro imaging techniques in the neurodegenerative diseases as a complement to in vivo positron emission tomography and single photon emission computed tomography imaging.

  10. Tablet surface characterisation by various imaging techniques

    DEFF Research Database (Denmark)

    Seitavuopio, Paulus; Rantanen, Jukka; Yliruusi, Jouko

    2003-01-01

    The aim of this study was to characterise tablet surfaces using different imaging and roughness analytical techniques including optical microscopy, scanning electron microscopy (SEM), laser profilometry and atomic force microscopy (AFM). The test materials compressed were potassium chloride (KCl......) and sodium chloride (NaCl). It was found that all methods used suggested that the KCl tablets were smoother than the NaCl tablets and higher compression pressure made the tablets smoother. Imaging methods like optical microscopy and SEM can give useful information about the roughness of the sample surface...

  11. THz imaging techniques for nondestructive inspections

    Science.gov (United States)

    Kawase, Kodo; Shibuya, Takayuki; Hayashi, Shin'ichiro; Suizu, Koji

    2010-08-01

    We have suggested a wide range of real-life applications using novel terahertz imaging techniques. A high-resolution terahertz tomography has been demonstrated by ultra short terahertz pulses using optical fiber and a nonlinear organic crystal. We also describe a nondestructive inspection system that can monitor the soot distribution in a ceramic filter using millimeter-to-terahertz wave computed tomography. Further, we report on the thickness measurement of very thin films using high-sensitivity metal mesh filter. These techniques are directly applicable to the nondestructive testing in industries.

  12. Comparison of four paper imaging techniques

    International Nuclear Information System (INIS)

    Tomimasu, H.; Kim, D.; Suk, M.; Luner, P.

    1991-01-01

    This paper discusses four paper imaging techniques (β-radiography, electrography, light transmission, and soft X-radiography) which were compared in terms of their process parameters and image characteristics (exposure time, spatial variation, contrast, spatial resolution, correlation with mass, and limitation in basis weight range) with the same newsprint samples and the same electron microscope film. Electrography gave a higher spatial resolution, shorter exposure time, and the wider basis weight range than β-radiography. The light transmission image could be obtained in a very short time, but it gave the poorest spatial resolution and correlation with mass. Soft X-radiography gave the biggest spatial resolution but the poorest spatial variation and contrast

  13. Advanced imaging techniques in pediatric body MRI

    Energy Technology Data Exchange (ETDEWEB)

    Courtier, Jesse [UCSF Benioff Children' s Hospital, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Anupindi, Sudha A. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2017-05-15

    While there are many challenges specific to pediatric abdomino-pelvic MRI, many recent advances are addressing these challenges. It is therefore essential for radiologists to be familiar with the latest advances in MR imaging. Laudable efforts have also recently been implemented in many centers to improve the overall experience of pediatric patients, including the use of dedicated radiology child life specialists, MRI video goggles, and improved MR suite environments. These efforts have allowed a larger number of children to be scanned while awake, with fewer studies being done under sedation or anesthesia; this has resulted in additional challenges from patient motion and difficulties with breath-holding and tolerating longer scan times. In this review, we highlight common challenges faced in imaging the pediatric abdomen and pelvis and discuss the application of the newest techniques to address these challenges. Additionally, we highlight the newest advances in quantified imaging techniques, specifically in MR liver iron quantification. The techniques described in this review are all commercially available and can be readily implemented. (orig.)

  14. Upright CBCT: A novel imaging technique

    Directory of Open Access Journals (Sweden)

    Xenia J Fave

    2014-03-01

    Full Text Available Purpose: We present a method for acquiring and correcting upright images using the on board CBCT imager. An upright imaging technique would allow for the introduction of upright radiation therapy treatments, which would benefit a variety of patients including those with thoracic cancers whose lung volumes are increased in an upright position and those who experience substantial discomfort during supine treatment positions.Methods: To acquire upright CBCT images, the linac head was positioned at 0 degrees, the KV imager and detector arms extended to their lateral positions, and the couch placed at 270 degrees. The KV imager was programmed to begin taking continuous fluoroscopic projections as the couch rotated from 270 to 90 degrees. The FOV was extended by performing this procedure twice, once with the detector shifted 14.5 cm towards the gantry and once with it shifted 14.5 cm away from the gantry. The two resulting sets of images were stitched together prior to reconstruction. The imaging parameters were chosen to deliver the some dose as that delivered during a simulation CT. A simulation CT was deformably registered to an upright CBCT reconstruction in order to evaluate the possibility of correcting the HU values via mapping.Results: Both spatial linearity and high contrast resolution were maintained in upright CBCT when compared to a simulation CT. Low contrast resolution and HU linearity decreased. Streaking artifacts were caused by the limited 180 degree arc angle and a sharp point artifact in the center of the axial slices resulted at the site of the stitching. A method for correcting the HUs was shown to be robust against these artifacts.Conclusion: Upright CBCT could be of great benefit to many patients. This study demonstrates its feasibility and presents solutions to some of its first hurdles before clinical implementation.--------------------------Cite this article as:Fave X, Yang J, Balter P, Court L. Upright CBCT: A novel imaging

  15. Flame analysis using image processing techniques

    Science.gov (United States)

    Her Jie, Albert Chang; Zamli, Ahmad Faizal Ahmad; Zulazlan Shah Zulkifli, Ahmad; Yee, Joanne Lim Mun; Lim, Mooktzeng

    2018-04-01

    This paper presents image processing techniques with the use of fuzzy logic and neural network approach to perform flame analysis. Flame diagnostic is important in the industry to extract relevant information from flame images. Experiment test is carried out in a model industrial burner with different flow rates. Flame features such as luminous and spectral parameters are extracted using image processing and Fast Fourier Transform (FFT). Flame images are acquired using FLIR infrared camera. Non-linearities such as thermal acoustic oscillations and background noise affect the stability of flame. Flame velocity is one of the important characteristics that determines stability of flame. In this paper, an image processing method is proposed to determine flame velocity. Power spectral density (PSD) graph is a good tool for vibration analysis where flame stability can be approximated. However, a more intelligent diagnostic system is needed to automatically determine flame stability. In this paper, flame features of different flow rates are compared and analyzed. The selected flame features are used as inputs to the proposed fuzzy inference system to determine flame stability. Neural network is used to test the performance of the fuzzy inference system.

  16. Probabilistic image: a concise image representation technique for multiple parameters

    Energy Technology Data Exchange (ETDEWEB)

    Wu, L.C.; Yeh, S.H.; Liu, R.S. (Veterans General Hospital, Taiwan; National Yang-Mills Medical Coll., Taipei, Taiwan); Chen, Z. (National Chiao Tung Univ., Hsinchu, Taiwan)

    1984-09-01

    In scintiscanning studies, an attempt has been made to use multiple parametric information to evaluate functional abnormalities in human organs, using the probabilistic domain instead of the parametric domain to present single or multiple parameters in one image. The construction of such a probabilistic image (PBI) has been illustrated from a /sup 99/Tcsup(m)-HIDA study in 32 normal subjects and in 20 patients with intrahepatic lithiasis. The results show that this technique shows the functional abnormalities in a structural format with a good contrast and probabilistic sense.

  17. Special feature on imaging systems and techniques

    Science.gov (United States)

    Yang, Wuqiang; Giakos, George

    2013-07-01

    The IEEE International Conference on Imaging Systems and Techniques (IST'2012) was held in Manchester, UK, on 16-17 July 2012. The participants came from 26 countries or regions: Austria, Brazil, Canada, China, Denmark, France, Germany, Greece, India, Iran, Iraq, Italy, Japan, Korea, Latvia, Malaysia, Norway, Poland, Portugal, Sweden, Switzerland, Taiwan, Tunisia, UAE, UK and USA. The technical program of the conference consisted of a series of scientific and technical sessions, exploring physical principles, engineering and applications of new imaging systems and techniques, as reflected by the diversity of the submitted papers. Following a rigorous review process, a total of 123 papers were accepted, and they were organized into 30 oral presentation sessions and a poster session. In addition, six invited keynotes were arranged. The conference not only provided the participants with a unique opportunity to exchange ideas and disseminate research outcomes but also paved a way to establish global collaboration. Following the IST'2012, a total of 55 papers, which were technically extended substantially from their versions in the conference proceeding, were submitted as regular papers to this special feature of Measurement Science and Technology . Following a rigorous reviewing process, 25 papers have been finally accepted for publication in this special feature and they are organized into three categories: (1) industrial tomography, (2) imaging systems and techniques and (3) image processing. These papers not only present the latest developments in the field of imaging systems and techniques but also offer potential solutions to existing problems. We hope that this special feature provides a good reference for researchers who are active in the field and will serve as a catalyst to trigger further research. It has been our great pleasure to be the guest editors of this special feature. We would like to thank the authors for their contributions, without which it would

  18. Advanced Imaging Techniques for Multiphase Flows Analysis

    Science.gov (United States)

    Amoresano, A.; Langella, G.; Di Santo, M.; Iodice, P.

    2017-08-01

    Advanced numerical techniques, such as fuzzy logic and neural networks have been applied in this work to digital images acquired on two applications, a centrifugal pump and a stationary spray in order to define, in a stochastic way, the gas-liquid interface evolution. Starting from the numeric matrix representing the image it is possible to characterize geometrical parameters and the time evolution of the jet. The algorithm used works with the fuzzy logic concept to binarize the chromatist of the pixels, depending them, by using the difference of the light scattering for the gas and the liquid phase.. Starting from a primary fixed threshold, the applied technique, can select the ‘gas’ pixel from the ‘liquid’ pixel and so it is possible define the first most probably boundary lines of the spray. Acquiring continuously the images, fixing a frame rate, a most fine threshold can be select and, at the limit, the most probably geometrical parameters of the jet can be detected.

  19. Atherosclerosis staging: imaging using FLIM technique

    Science.gov (United States)

    Sicchieri, Leticia B.; Barioni, Marina Berardi; Silva, Mônica Nascimento; Monteiro, Andrea Moreira; Figueiredo Neto, Antonio Martins; Ito, Amando S.; Courrol, Lilia C.

    2014-03-01

    In this work it was used fluorescence lifetime imaging (FLIM) to analyze biochemical composition of atherosclerotic plaque. For this purpose an animal experimentation was done with New Zealand rabbits divided into two groups: a control group of 4 rabbits that received a regular diet for 0, 20, 40 and 60 days; and an experimental group of 9 rabbits, divided in 3 subgroups, that were fed with 1% cholesterol diet for 20, 40 and 60 days respectively. The aortas slices stained with europium chlortetracycline were analyzed by FLIM exciting samples at 440 nm. The results shown an increase in the lifetime imaging of rabbits fed with cholesterol. It was observed that is possible to detect the metabolic changes associated with atherosclerosis at an early stage using FLIM technique exciting the tissue around 440 nm and observing autofluorescence lifetime. Lifetimes longer than 1.75 ns suggest the presence of porphyrins in the tissue and consequently, inflammation and the presence of macrophages.

  20. Computer technique for correction of nonhomogeneous distribution in radiologic images

    International Nuclear Information System (INIS)

    Florian, Rogerio V.; Frere, Annie F.; Schiable, Homero; Marques, Paulo M.A.; Marques, Marcio A.

    1996-01-01

    An image processing technique to provide a 'Heel' effect compensation on medical images is presented. It is reported that the technique can improve the structures detection due to background homogeneity and can be used for any radiologic system

  1. Ultrasonic imaging in LMFBRs using digital techniques

    International Nuclear Information System (INIS)

    Fothergill, J.R.; McKnight, J.A.; Barrett, L.M.

    Ultrasonic technology for providing images of components immersed in the opaque sodium of LMFBRs is being developed at RNL. For many years the application has been restricted by the unavailability of convenient ultrasonic sources and receivers capable of withstanding the reactor environment. Until recently, for example, important ultrasonic instrument design, such as for future sweep arms, had to be based on waveguided ultrasonics. RNL have developed an economic immersible transducer that can be deployed during reactor shut-down, when many demands for ultrasonic imaging are made. The transducer design is not suited at present to the sophisticated techniques of phased arrays; consequently image formation must depend on the physical scanning of a target using one or more transducers in pulse-echo mode. The difficulties of access into a fast reactor impose further restrictions. Some applications may involve easy scanning sequences, thus the sweep arm requires only a rotation to provide a map of the reactor core area. For a more detailed examination of the same area, however, special engineering solutions are needed to provide a more satisfactory scanning sequence. A compromise solution involving the rotating shield movement is being used for a PFR experiment to examine a limited area of the core. (author)

  2. Three dimensional image presentation techniques in medical imaging

    International Nuclear Information System (INIS)

    Pizer, S.M.; Fuchs, H.

    1987-01-01

    Medical images can be presented three-dimensionally by techniques that either calculate the effect of reflections from surfaces predefined from slices or project a three-space of luminosities computed from voxel intensities onto the visual receptors. Sliced-based reflective displays are the most common type. Means of producing surface descriptions both via voxel sets and via slice contours are reviewed. Advantages of and means of transparent display to allow the appreciation of the 3D relationships among objects are set forth. Ways to produce additional depth cues by stereoscopy and the kinetic depth effect are discussed, and the importance of interactive modification of viewpoint, clipping plane, displayed objects, etc. are explained. A new device, UNC's Pixel-planes, for accomplishing this in real time are illustrated. Voxel intensity based display methods avoid the need for time-consuming predefinition of object surfaces and thus can allow exploration of 3D image data. Varifocal mirror hardware and fast computation of one or more projections based on object probabilities are two of the more important approaches. While 3D display provides important information about 3D relationships, it cannot provide the kind of appreciation of subtle grey-scale changes that 2D display can. Methods that can combine these two kinds of information by superimposing 2D grey-scale slices on or in the context of 3D displays are discussed. Applications of these techniques for both diagnosis and radiotherapy planning are used as illustrations and guides to the usefulness of these techniques with CT, MRI, and other 3D medical imaging modalities. 24 refs.; 5 figs

  3. Use of imaging techniques in radiation oncology

    International Nuclear Information System (INIS)

    Borras, C.; Rudder, D.; Jimenez, P.

    2002-01-01

    Imaging techniques are used in radiation oncology for: disease diagnosis, tumor localization and staging, treatment simulation, treatment planning, clinical dosimetry displays, treatment verification and patient follow up. In industrialized countries, up to the 1970's, conventional radiology was used for diagnosis, simulation and planning. Gamma cameras helped tumor staging by detecting metastases. In the 1970's, simulators were developed for exclusive use in radiation oncology departments. Clinical dosimetry displays consisted mainly in axial dose distributions. Treatment verification was done placing films in the radiation beam with the patient under treatment. In the 1980's, 2-D imaging was replaced by 3-D displays with the incorporation of computerized tomography (CT) scanners, and in the 1990's of magnetic resonance imagers (MRI). Ultrasound units, briefly used in the 1960's for treatment planning purposes, were found again useful, mainly for brachytherapy dosimetry. Digital portal imagers allowed accurate treatment field verification. Treatment planning systems incorporated the capability of 'inverse planning', i.e. once the desired dose distribution is decided, the field size, gantry, collimator and couch angles, etc, can be automatically selected. At the end of the millennium, image fusion permitted excellent anatomical display of tumors and adjacent sensitive structures. The 2000's are seeing a change from anatomical to functional imaging with the advent of MRI units capable of spectroscopy at 3 Tesla and positron emission tomography (PET) units. In 2001 combined CT/PET units appeared in RT departments. In 2002, fusion of CT, MRI and PET images became available. Molecular imaging is being developed. The situation in developing countries is quite different. To start with, cancer incidence is different in developing and in industrialized countries. In addition, the health services pattern is different: Cancer treatment is mostly done in public institutions

  4. Image Recognition Techniques for Earthquake Early Warning

    Science.gov (United States)

    Boese, M.; Heaton, T. H.; Hauksson, E.

    2011-12-01

    When monitoring on his/her PC a map of seismic stations, whose colors scale with the real-time transmitted ground motions amplitudes observed in a dense seismic network, an experienced person will fairly easily recognize when and where an earthquake occurs. Using the maximum amplitudes at stations at close epicentral distances, he/she might even be able to roughly estimate the size of the event. From the number and distribution of stations turning 'red', the person might also be able to recognize the rupturing fault in a large earthquake (M>>7.0), and to estimate the rupture dimensions while the rupture is still developing. Following this concept, we are adopting techniques for automatic image recognition to provide earthquake early warning. We rapidly correlate a set of templates with real-time ground motion observations in a seismic network. If a 'suspicious' pattern of ground motion amplitudes is detected, the algorithm starts estimating the location of the earthquake and its magnitude. For large earthquakes the algorithm estimates finite source dimensions and the direction of rupture propagation. These predictions are continuously up-dated using the current 'image' of ground motion observations. A priori information, such as on the orientation of mayor faults, helps enhancing estimates in less dense networks. The approach will be demonstrated for multiple simulated and real events in California.

  5. Development of imaging techniques for fast neutron radiography in Japan

    International Nuclear Information System (INIS)

    Fujine, Shigenori; Yoneda, Kenji; Yoshii, Koji; Kamata, Masahiro; Tamaki, Masayoshi; Ohkubo, Kohei; Ikeda, Yasushi; Kobayashi, Hisao

    1999-01-01

    Neutron radiography with fast neutron beams (FNR) has been studied at the fast neutron source reactor 'YAYOI' of the University of Tokyo since 1986. Imaging techniques for FNR have been developed for CR-39 track-etch detector, electronic imaging system (television method), direct film method, imaging plate and also fast and thermal neutron concurrent imaging method. The review of FNR imaging techniques and some applications are reported in this paper

  6. Dentomaxillofacial imaging with computed-radiography techniques: a preliminary study

    Science.gov (United States)

    Shaw, Chris C.; Kapa, Stanley F.; Furkart, Audrey J.; Gur, David

    1993-09-01

    A preliminary study was conducted to investigate the feasibility of using high resolution computed radiography techniques for dentomaxillofacial imaging. Storage phosphors were cut into various sizes and used with an experimental laser scanning reader for three different imaging procedures: intraoral, cephalometric and panoramic. Both phantom and patient images were obtained for comparing the computed radiography technique with the conventional screen/film or dental film techniques. It has been found that current computed radiography techniques are largely adequate for cephalometric and panoramic imaging but need further improvement on their spatial resolution capability for intraoral imaging. In this paper, the methods of applying the computer radiography techniques to dentomaxillofacial imaging are described and discussed. Images of phantoms, resolution bar patterns and patients are presented and compared. Issues on image quality and cost are discussed.

  7. A novel image inpainting technique based on median diffusion

    Indian Academy of Sciences (India)

    Image inpainting is the technique of filling-in the missing regions and removing unwanted objects from an image by diffusing the pixel information from the neighbourhood pixels. Image inpainting techniques are in use over a long time for various applications like removal of scratches, restoring damaged/missing portions or ...

  8. A review of equine renal imaging techniques

    International Nuclear Information System (INIS)

    Matthews, H.K.; Toal, R.L.

    1996-01-01

    Radiography has a limited role in the evaluation of the kidneys in foals and adult horses. Ultrasonography is the current method of choice for structural evaluation of the kidneys in horses as it provides additional information to standard serum chemistry and urinalysis evaluation. A variety of structural abnormalities have been identified in diseased equine kidneys with the use of ultrasound. Ultrasound guided renal biopsy is the preferred method for performing renal biopsy in the horse. The use of Duplex Doppler ultrasound may allow for the characterization of regional hemodynamics of the equine kidney, but is currently an untapped method for evaluation of equine renal hemodynamics. Radionuclide methods including scintigraphy and quantitative renal function measurement can be used to provide further information about equine renal function. Scintigraphy can provide structural and possibly functional information. Quantitative methods using radiopharmaceuticals can provide precise measurement of glomerular filtration rate and effective renal blood flow. This method is especially helpful in identifying acute renal failure and in guiding response to treatment. All equine renal imaging techniques should be a supplement to the physical examination and standard laboratory tests. Additional diagnostic aids such as urinary tract endoscopy should also be considered in horses with hematuria, hydroureter, and suspected calculi. Taken together, all these modalities provide a thorough evaluation of the equine renal system and provide a basis for the clinician to select treatment options and provide prognostic information to the owner

  9. A review of imaging techniques for plant phenotyping.

    Science.gov (United States)

    Li, Lei; Zhang, Qin; Huang, Danfeng

    2014-10-24

    Given the rapid development of plant genomic technologies, a lack of access to plant phenotyping capabilities limits our ability to dissect the genetics of quantitative traits. Effective, high-throughput phenotyping platforms have recently been developed to solve this problem. In high-throughput phenotyping platforms, a variety of imaging methodologies are being used to collect data for quantitative studies of complex traits related to the growth, yield and adaptation to biotic or abiotic stress (disease, insects, drought and salinity). These imaging techniques include visible imaging (machine vision), imaging spectroscopy (multispectral and hyperspectral remote sensing), thermal infrared imaging, fluorescence imaging, 3D imaging and tomographic imaging (MRT, PET and CT). This paper presents a brief review on these imaging techniques and their applications in plant phenotyping. The features used to apply these imaging techniques to plant phenotyping are described and discussed in this review.

  10. A Review of Imaging Techniques for Plant Phenotyping

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-10-01

    Full Text Available Given the rapid development of plant genomic technologies, a lack of access to plant phenotyping capabilities limits our ability to dissect the genetics of quantitative traits. Effective, high-throughput phenotyping platforms have recently been developed to solve this problem. In high-throughput phenotyping platforms, a variety of imaging methodologies are being used to collect data for quantitative studies of complex traits related to the growth, yield and adaptation to biotic or abiotic stress (disease, insects, drought and salinity. These imaging techniques include visible imaging (machine vision, imaging spectroscopy (multispectral and hyperspectral remote sensing, thermal infrared imaging, fluorescence imaging, 3D imaging and tomographic imaging (MRT, PET and CT. This paper presents a brief review on these imaging techniques and their applications in plant phenotyping. The features used to apply these imaging techniques to plant phenotyping are described and discussed in this review.

  11. A Review of Imaging Techniques for Plant Phenotyping

    Science.gov (United States)

    Li, Lei; Zhang, Qin; Huang, Danfeng

    2014-01-01

    Given the rapid development of plant genomic technologies, a lack of access to plant phenotyping capabilities limits our ability to dissect the genetics of quantitative traits. Effective, high-throughput phenotyping platforms have recently been developed to solve this problem. In high-throughput phenotyping platforms, a variety of imaging methodologies are being used to collect data for quantitative studies of complex traits related to the growth, yield and adaptation to biotic or abiotic stress (disease, insects, drought and salinity). These imaging techniques include visible imaging (machine vision), imaging spectroscopy (multispectral and hyperspectral remote sensing), thermal infrared imaging, fluorescence imaging, 3D imaging and tomographic imaging (MRT, PET and CT). This paper presents a brief review on these imaging techniques and their applications in plant phenotyping. The features used to apply these imaging techniques to plant phenotyping are described and discussed in this review. PMID:25347588

  12. Experimental and theoretical contributions to X-ray phase-contrast techniques for medical imaging

    International Nuclear Information System (INIS)

    Diemoz, P.C.

    2011-01-01

    Several X-ray phase-contrast techniques have recently been developed. Unlike conventional X-ray methods, which measure the absorption properties of the tissues, these techniques derive contrast also from the modulation of the phase produced by the sample. Since the phase shift can be significant even for small details characterized by weak or absent absorption, the achievable image contrast can be greatly increased, notably for the soft biological tissues. These methods are therefore very promising for applications in the medical domain. The aim of this work is to contribute to a deeper understanding of these techniques, in particular propagation-based imaging (PBI), analyzer-based imaging (ABI) and grating interferometry (GIFM), and to study their potential and the best practical implementation for medical imaging applications. An important part of this work is dedicated to the use of mathematical algorithms for the extraction, from the acquired images, of quantitative sample information (the absorption, refraction and scattering sample properties). In particular, five among the most known algorithms based on the geometrical optics approximation have been theoretically analysed and experimentally compared, in planar and tomographic modalities, by using geometrical phantoms and human bone-cartilage and breast samples. A semi-quantitative method for the acquisition and reconstruction of tomographic images in the ABI and GIFM techniques has also been proposed. The validity conditions are analyzed in detail and the method, enabling a considerable simplification of the imaging procedure, has been experimentally checked on phantoms and human samples. Finally, a theoretical and experimental comparison of the PBI, ABI and GIFM techniques is presented. The advantages and drawbacks of each of these techniques are discussed. The results obtained from this analysis can be very useful for determining the most adapted technique for a given application. (author)

  13. Digital image processing techniques in archaeology

    Digital Repository Service at National Institute of Oceanography (India)

    Santanam, K.; Vaithiyanathan, R.; Tripati, S.

    Digital image processing involves the manipulation and interpretation of digital images with the aid of a computer. This form of remote sensing actually began in the 1960's with a limited number of researchers analysing multispectral scanner data...

  14. Imaging fault zones using 3D seismic image processing techniques

    Science.gov (United States)

    Iacopini, David; Butler, Rob; Purves, Steve

    2013-04-01

    Significant advances in structural analysis of deep water structure, salt tectonic and extensional rift basin come from the descriptions of fault system geometries imaged in 3D seismic data. However, even where seismic data are excellent, in most cases the trajectory of thrust faults is highly conjectural and still significant uncertainty exists as to the patterns of deformation that develop between the main faults segments, and even of the fault architectures themselves. Moreover structural interpretations that conventionally define faults by breaks and apparent offsets of seismic reflectors are commonly conditioned by a narrow range of theoretical models of fault behavior. For example, almost all interpretations of thrust geometries on seismic data rely on theoretical "end-member" behaviors where concepts as strain localization or multilayer mechanics are simply avoided. Yet analogue outcrop studies confirm that such descriptions are commonly unsatisfactory and incomplete. In order to fill these gaps and improve the 3D visualization of deformation in the subsurface, seismic attribute methods are developed here in conjunction with conventional mapping of reflector amplitudes (Marfurt & Chopra, 2007)). These signal processing techniques recently developed and applied especially by the oil industry use variations in the amplitude and phase of the seismic wavelet. These seismic attributes improve the signal interpretation and are calculated and applied to the entire 3D seismic dataset. In this contribution we will show 3D seismic examples of fault structures from gravity-driven deep-water thrust structures and extensional basin systems to indicate how 3D seismic image processing methods can not only build better the geometrical interpretations of the faults but also begin to map both strain and damage through amplitude/phase properties of the seismic signal. This is done by quantifying and delineating the short-range anomalies on the intensity of reflector amplitudes

  15. A Hybrid Technique for Medical Image Segmentation

    Directory of Open Access Journals (Sweden)

    Alamgir Nyma

    2012-01-01

    Full Text Available Medical image segmentation is an essential and challenging aspect in computer-aided diagnosis and also in pattern recognition research. This paper proposes a hybrid method for magnetic resonance (MR image segmentation. We first remove impulsive noise inherent in MR images by utilizing a vector median filter. Subsequently, Otsu thresholding is used as an initial coarse segmentation method that finds the homogeneous regions of the input image. Finally, an enhanced suppressed fuzzy c-means is used to partition brain MR images into multiple segments, which employs an optimal suppression factor for the perfect clustering in the given data set. To evaluate the robustness of the proposed approach in noisy environment, we add different types of noise and different amount of noise to T1-weighted brain MR images. Experimental results show that the proposed algorithm outperforms other FCM based algorithms in terms of segmentation accuracy for both noise-free and noise-inserted MR images.

  16. The technique of Cerenkov ring image detection

    International Nuclear Information System (INIS)

    Langerveld, D.

    1990-01-01

    Charged particles with an energy between 2 GeV and 25 GeV can be identified in the DELPHI barrel RICH detector by using the technique of Cerenkov ring image detection. The method of identification is based on a determination of the Cerenkov angle by measuring the positions of the emitted Cerenkov photons to high precision in a photon detector. The resolution in the photon that can be obtained depends mainly on the chromatic dispersion in the radiators and on the resolution in the photon detector is used in the barrel RICH in combination with two radiators. The photon detector consists of 48 drift tubes, constructed from quarz plates, each equipped with a wire chamber at the end. The drift gas with which the tubes are filled contains a small admixture of TMAE vapour from which the Cerenkov photons can liberate photoelectrons. It is shown in this thesis that an efficient photon detection and an accurate localization of the photon conversion points is possible. The spatial resolution of the photon detector is determind by the resolution of the wire chambe, the accuracy of the drift measurement, the distortions in the paths of the drifting electrons. The resolution of the wire chamber has been measured to be 0.8 mm in the x- and 1.7 mm in the y-coordinate. The error in the z-coordinate introduced by the drift time measurement is 0.2 mm. The distortions in the paths of the drifting electrons have been measured both in the x and y-direction. The longitudinal and transverse diffusion coefficients have been measured as a function of the field strength for two different drift gas mixtures. (author). 96 refs.; 61 figs.; 11 tabs

  17. Application of digital image processing techniques to astronomical imagery 1977

    Science.gov (United States)

    Lorre, J. J.; Lynn, D. J.

    1978-01-01

    Nine specific techniques of combination of techniques developed for applying digital image processing technology to existing astronomical imagery are described. Photoproducts are included to illustrate the results of each of these investigations.

  18. Applying the digital-image-correlation technique to measure the ...

    Indian Academy of Sciences (India)

    digital-image-correlation) technique is used to measure the deformation of the retrofitted column. The result shows that the DIC technique can be successfully applied to measure the relative displacement of the column. Additionally, thismethod ...

  19. A content-based image retrieval method for optical colonoscopy images based on image recognition techniques

    Science.gov (United States)

    Nosato, Hirokazu; Sakanashi, Hidenori; Takahashi, Eiichi; Murakawa, Masahiro

    2015-03-01

    This paper proposes a content-based image retrieval method for optical colonoscopy images that can find images similar to ones being diagnosed. Optical colonoscopy is a method of direct observation for colons and rectums to diagnose bowel diseases. It is the most common procedure for screening, surveillance and treatment. However, diagnostic accuracy for intractable inflammatory bowel diseases, such as ulcerative colitis (UC), is highly dependent on the experience and knowledge of the medical doctor, because there is considerable variety in the appearances of colonic mucosa within inflammations with UC. In order to solve this issue, this paper proposes a content-based image retrieval method based on image recognition techniques. The proposed retrieval method can find similar images from a database of images diagnosed as UC, and can potentially furnish the medical records associated with the retrieved images to assist the UC diagnosis. Within the proposed method, color histogram features and higher order local auto-correlation (HLAC) features are adopted to represent the color information and geometrical information of optical colonoscopy images, respectively. Moreover, considering various characteristics of UC colonoscopy images, such as vascular patterns and the roughness of the colonic mucosa, we also propose an image enhancement method to highlight the appearances of colonic mucosa in UC. In an experiment using 161 UC images from 32 patients, we demonstrate that our method improves the accuracy of retrieving similar UC images.

  20. Application of digital imaging techniques to flare monitoring

    International Nuclear Information System (INIS)

    Rodrigues, Shaun J; Yan, Yong

    2011-01-01

    This paper presents a technique for detecting and monitoring flares in harsh industrial environments with the use of an imaging sensor combined with digital image processing. Flare images are captured via an imaging fibre and analysed to detect the flare's presence and region of interest. The flare characteristics are then determined using various image processing algorithms. A prototype system is designed, constructed and evaluated on a purpose built laboratory scale flare test rig. Results indicate that the imaging based technique has potential for the detection, monitoring and analysis of flares amidst various background conditions in the chemical and oil industries for plant safety, pollution prevention and control.

  1. Development of flow velocity measurement techniques in visible images. Improvement of particle image velocimetry techniques on image process

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Nobuyuki; Nishimura, Motohiko; Kamide, Hideki; Hishida, Koichi [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Miyake, Yasuhiro [NDD Corporation, Tokyo (Japan)

    1999-10-01

    Noise reduction system was developed to improve applicability of Particle Image Velocimetry (PIV) to complicated configure bounded flows. For fast reactor safety and thermal hydraulic studies, experiments are performed in scale models which usually have rather complicated geometry and structures such as fuel subassemblies, heat exchangers, etc. The structures and stuck dusts on the view window of the models obscure the particle image. Thus the image except the moving particles can be regarded as a noise. In the present study, two noise reduction techniques are proposed. The one is the Time-averaged Light Intensity Subtraction method (TIS) which subtracts the time-averaged light intensity of each pixel in the sequential images from the each corresponding pixel. The other one is the Minimum Light Intensity Subtraction method (MIS) which subtracts the minimum light intensity of each pixel in the sequential images from the each corresponding pixel. Both methods are examined on their capabilities of noise reduction. As for the original 'bench mark' image, the image made from Large Eddy Simulation was used. To the bench mark image, noises are added which are referred as sample images. Both methods reduce the rate of vector with the error of more than one pixel from 90% to less than 5%. Also, more than 50% of the vectors have the error of less than 0.2 pixel. The analysis of uncertainty shows that these methods enhances the accuracy of vector measurement 3 {approx} 12 times if the image with noise were processed, and the MIS method has 1.1 {approx} 2.1 times accuracy compared to the TIS. Thus the present noise reduction methods are quite efficient to enhance the accuracy of flow velocity fields measured with particle images including structures and deposits on the view window. (author)

  2. Development of flow velocity measurement techniques in visible images. Improvement of particle image velocimetry techniques on image process

    International Nuclear Information System (INIS)

    Kimura, Nobuyuki; Nishimura, Motohiko; Kamide, Hideki; Hishida, Koichi

    1999-10-01

    Noise reduction system was developed to improve applicability of Particle Image Velocimetry (PIV) to complicated configure bounded flows. For fast reactor safety and thermal hydraulic studies, experiments are performed in scale models which usually have rather complicated geometry and structures such as fuel subassemblies, heat exchangers, etc. The structures and stuck dusts on the view window of the models obscure the particle image. Thus the image except the moving particles can be regarded as a noise. In the present study, two noise reduction techniques are proposed. The one is the Time-averaged Light Intensity Subtraction method (TIS) which subtracts the time-averaged light intensity of each pixel in the sequential images from the each corresponding pixel. The other one is the Minimum Light Intensity Subtraction method (MIS) which subtracts the minimum light intensity of each pixel in the sequential images from the each corresponding pixel. Both methods are examined on their capabilities of noise reduction. As for the original 'bench mark' image, the image made from Large Eddy Simulation was used. To the bench mark image, noises are added which are referred as sample images. Both methods reduce the rate of vector with the error of more than one pixel from 90% to less than 5%. Also, more than 50% of the vectors have the error of less than 0.2 pixel. The analysis of uncertainty shows that these methods enhances the accuracy of vector measurement 3 ∼ 12 times if the image with noise were processed, and the MIS method has 1.1 ∼ 2.1 times accuracy compared to the TIS. Thus the present noise reduction methods are quite efficient to enhance the accuracy of flow velocity fields measured with particle images including structures and deposits on the view window. (author)

  3. Vesical endometriosis: utility of imaging techniques

    International Nuclear Information System (INIS)

    Parra, M.; Cascon, E.; Robledo, R.; Perez, M.

    1999-01-01

    We present three cases of vesical endometriosis initially studied with ultrasound. One case was also studied with intravenous urography, computed tomography and magnetic resonance imaging. We discuss on the utility of these imaging methods in the diagnosis of vesical endometriosis. (Author) 9 refs

  4. New imaging techniques for liver diseases.

    Science.gov (United States)

    Van Beers, Bernard E; Daire, Jean-Luc; Garteiser, Philippe

    2015-03-01

    Newly developed or advanced methods of ultrasonography and MR imaging provide combined anatomical and quantitative functional information about diffuse and focal liver diseases. Ultrasound elastography has a central role for staging liver fibrosis and an increasing role in grading portal hypertension; dynamic contrast-enhanced ultrasonography may improve tumor characterization. In clinical practice, MR imaging examinations currently include diffusion-weighted and dynamic MR imaging, enhanced with extracellular or hepatobiliary contrast agents. Moreover, quantitative parameters obtained with diffusion-weighted MR imaging, dynamic contrast-enhanced MR imaging and MR elastography have the potential to characterize further diffuse and focal liver diseases, by adding information about tissue cellularity, perfusion, hepatocyte transport function and visco-elasticity. The multiparametric capability of ultrasonography and more markedly of MR imaging gives the opportunity for high diagnostic performance by combining imaging biomarkers. However, image acquisition and post-processing methods should be further standardized and validated in multicenter trials. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  5. Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments.

    Science.gov (United States)

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-03-01

    In tissue engineering, non-invasive imaging of biomaterial scaffolds and tissues in living systems is essential to longitudinal animal studies for assessments without interrupting the repair process. Conventional X-ray imaging is inadequate for use in soft tissue engineering due to the limited absorption difference between the soft tissue and biomaterial scaffolds. X-ray phase-based imaging techniques that derive contrast from refraction or phase effects rather than absorption can provide the necessary contrast to see low-density biomaterial scaffolds and tissues in large living systems. This paper explores and compares three synchrotron phase-based X-ray imaging techniques-computed tomography (CT)-diffraction enhanced imaging (DEI), -analyzer based imaging (ABI), and -phase contrast imaging (PCI)-for visualization and characterization of low-density biomaterial scaffolds and tissues in situ for non-invasive soft tissue engineering assessments. Intact pig joints implanted with polycaprolactone scaffolds were used as the model to assess and compare the imaging techniques in terms of different qualitative and quantitative criteria. For long-term in vivo live animal imaging, different strategies for reducing the imaging radiation dose and scan time-reduced number of CT projections, region of interest, and low resolution imaging-were examined with the presented phase-based imaging techniques. The results demonstrated promising capabilities of the phase-based techniques for visualization of biomaterial scaffolds and soft tissues in situ. The low-dose imaging strategies were illustrated effective for reducing the radiation dose to levels appropriate for live animal imaging. The comparison among the imaging techniques suggested that CT-DEI has the highest efficiency in retaining image contrast at considerably low radiation doses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Color image Segmentation using automatic thresholding techniques

    International Nuclear Information System (INIS)

    Harrabi, R.; Ben Braiek, E.

    2011-01-01

    In this paper, entropy and between-class variance based thresholding methods for color images segmentation are studied. The maximization of the between-class variance (MVI) and the entropy (ME) have been used as a criterion functions to determine an optimal threshold to segment images into nearly homogenous regions. Segmentation results from the two methods are validated and the segmentation sensitivity for the test data available is evaluated, and a comparative study between these methods in different color spaces is presented. The experimental results demonstrate the superiority of the MVI method for color image segmentation.

  7. Unconventional techniques of fundus imaging: A review

    Directory of Open Access Journals (Sweden)

    Mahesh P Shanmugam

    2015-01-01

    Full Text Available The methods of fundus examination include direct and indirect ophthalmoscopy and imaging with a fundus camera are an essential part of ophthalmic practice. The usage of unconventional equipment such as a hand-held video camera, smartphone, and a nasal endoscope allows one to image the fundus with advantages and some disadvantages. The advantages of these instruments are the cost-effectiveness, ultra portability and ability to obtain images in a remote setting and share the same electronically. These instruments, however, are unlikely to replace the fundus camera but then would always be an additional arsenal in an ophthalmologist's armamentarium.

  8. Imaging techniques in transcatheter aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Quaife RA

    2013-11-01

    Full Text Available Robert A Quaife, Jennifer Dorosz, John C Messenger, Ernesto E Salcedo Division of Cardiology, University of Colorado, Aurora, CO, USA Abstract: Calcific aortic stenosis is now understood as a complex valvular degenerative process sharing many risk factors with atherosclerosis. Once patients develop symptomatic calcific aortic stenosis, the only effective treatment is aortic valve replacement. In the past decade, transcatheter aortic valve replacement (TAVR has been developed as an alternative to surgery to treat severe calcific aortic stenosis. Cardiac imaging plays a pivotal role in the contemporary management of patients with calcific aortic stenosis, and particularly in patients being considered for TAVR, who demand detailed imaging of the aortic valve apparatus. In this review, we highlight the role of cardiac imaging for patient selection, procedural guidance, and evaluation of results of TAVR. Keywords: aortic stenosis, cardiovascular imaging, transcutaneous aortic valve replacement

  9. An efficient similarity measure technique for medical image registration

    Indian Academy of Sciences (India)

    In this paper, an efficient similarity measure technique is proposed for medical image registration. The proposed approach is based on the Gerschgorin circles theorem. In this approach, image registration is carried out by considering Gerschgorin bounds of a covariance matrix of two compared images with normalized ...

  10. Image processing techniques for quantification and assessment of brain MRI

    NARCIS (Netherlands)

    Kuijf, H.J.

    2013-01-01

    Magnetic resonance imaging (MRI) is a widely used technique to acquire digital images of the human brain. A variety of acquisition protocols is available to generate images in vivo and noninvasively, giving great opportunities to study the anatomy and physiology of the human brain. In my thesis,

  11. Study and analysis of wavelet based image compression techniques ...

    African Journals Online (AJOL)

    This paper presented comprehensive study with performance analysis of very recent Wavelet transform based image compression techniques. Image compression is one of the necessities for such communication. The goals of image compression are to minimize the storage requirement and communication bandwidth.

  12. Red blood cell image enhancement techniques for cells with ...

    African Journals Online (AJOL)

    quality or challenging conditions of the images such as poor illumination of blood smear and most importantly overlapping RBC. The algorithm comprises of two RBC segmentation that can be selected based on the image quality, circle mask technique and grayscale blood smear image processing. Detail explanations ...

  13. Three-dimensional imaging techniques: A literature review

    Science.gov (United States)

    Karatas, Orhan Hakki; Toy, Ebubekir

    2014-01-01

    Imaging is one of the most important tools for orthodontists to evaluate and record size and form of craniofacial structures. Orthodontists routinely use 2-dimensional (2D) static imaging techniques, but deepness of structures cannot be obtained and localized with 2D imaging. Three-dimensional (3D) imaging has been developed in the early of 1990's and has gained a precious place in dentistry, especially in orthodontics. The aims of this literature review are to summarize the current state of the 3D imaging techniques and to evaluate the applications in orthodontics. PMID:24966761

  14. Techniques and software architectures for medical visualisation and image processing

    OpenAIRE

    Botha, C.P.

    2005-01-01

    This thesis presents a flexible software platform for medical visualisation and image processing, a technique for the segmentation of the shoulder skeleton from CT data and three techniques that make contributions to the field of direct volume rendering. Our primary goal was to investigate the use of visualisation techniques to assist the shoulder replacement process. This motivated the need for a flexible environment within which to test and develop new visualisation and also image processin...

  15. Advanced techniques in digital mammographic images recognition

    International Nuclear Information System (INIS)

    Aliu, R. Azir

    2011-01-01

    Computer Aided Detection and Diagnosis is used in digital radiography as a second thought in the process of determining diagnoses, which reduces the percentage of wrong diagnoses of the established interpretation of mammographic images. The issues that are discussed in the dissertation are the analyses and improvement of advanced technologies in the field of artificial intelligence, more specifically in the field of machine learning for solving diagnostic problems and automatic detection of speculated lesions in digital mammograms. The developed of SVM-based ICAD system with cascade architecture for analyses and comparison mammographic images in both projections (CC and MLO) gives excellent result for detection and masses and microcalcifications. In order to develop a system with optimal performances of sensitivity, specificity and time complexity, a set of relevant characteristics need to be created which will show all the pathological regions that might be present in the mammographic image. The structure of the mammographic image, size and the large number of pathological structures in this area are the reason why the creation of a set of these features is necessary for the presentation of good indicators. These pathological structures are a real challenge today and the world of science is working in that direction. The doctoral dissertation showed that the system has optimal results, which are confirmed by experts, and institutions, which are dealing with these same issues. Also, the thesis presents a new approach for automatic identification of regions of interest in the mammographic image where regions of interest are automatically selected for further processing mammography in cases when the number of examined patients is higher. Out of 480 mammographic images downloaded from MIAS database and tested with ICAD system the author shows that, after separation and selection of relevant features of ICAD system the accuracy is 89.7% (96.4% for microcalcifications

  16. Imaging in anatomy: a comparison of imaging techniques in embalmed human cadavers

    Science.gov (United States)

    2013-01-01

    Background A large variety of imaging techniques is an integral part of modern medicine. Introducing radiological imaging techniques into the dissection course serves as a basis for improved learning of anatomy and multidisciplinary learning in pre-clinical medical education. Methods Four different imaging techniques (ultrasound, radiography, computed tomography, and magnetic resonance imaging) were performed in embalmed human body donors to analyse possibilities and limitations of the respective techniques in this peculiar setting. Results The quality of ultrasound and radiography images was poor, images of computed tomography and magnetic resonance imaging were of good quality. Conclusion Computed tomography and magnetic resonance imaging have a superior image quality in comparison to ultrasound and radiography and offer suitable methods for imaging embalmed human cadavers as a valuable addition to the dissection course. PMID:24156510

  17. Full Parallax Integral 3D Display and Image Processing Techniques

    Directory of Open Access Journals (Sweden)

    Byung-Gook Lee

    2015-02-01

    Full Text Available Purpose – Full parallax integral 3D display is one of the promising future displays that provide different perspectives according to viewing direction. In this paper, the authors review the recent integral 3D display and image processing techniques for improving the performance, such as viewing resolution, viewing angle, etc.Design/methodology/approach – Firstly, to improve the viewing resolution of 3D images in the integral imaging display with lenslet array, the authors present 3D integral imaging display with focused mode using the time-multiplexed display. Compared with the original integral imaging with focused mode, the authors use the electrical masks and the corresponding elemental image set. In this system, the authors can generate the resolution-improved 3D images with the n×n pixels from each lenslet by using n×n time-multiplexed display. Secondly, a new image processing technique related to the elemental image generation for 3D scenes is presented. With the information provided by the Kinect device, the array of elemental images for an integral imaging display is generated.Findings – From their first work, the authors improved the resolution of 3D images by using the time-multiplexing technique through the demonstration of the 24 inch integral imaging system. Authors’ method can be applied to a practical application. Next, the proposed method with the Kinect device can gain a competitive advantage over other methods for the capture of integral images of big 3D scenes. The main advantage of fusing the Kinect and the integral imaging concepts is the acquisition speed, and the small amount of handled data.Originality / Value – In this paper, the authors review their recent methods related to integral 3D display and image processing technique.Research type – general review.

  18. Comparing imaging procedures: techniques and examples. Gastroenterology

    International Nuclear Information System (INIS)

    Malmud, L.S.

    1982-01-01

    The distinct advantages of nuclear medicine procedures, in comparison to radiography, contrast studies, computerized tomography and ultrasound, are emphasized. Scintigraphic methods offer quantitative data regarding function which competing imaging modalities are unable to provide, and make them the studies of choice in the evaluation of gastrointestinal physiology and functional abnormalities

  19. On the Image Watermarking Techniques Applications, Properties ...

    African Journals Online (AJOL)

    Abstract:With the coming and the expansion of the World Wide Web an increased amount of digital information, such as documents, images audio and video ... for copyright protection and a considerable interest in methods for inserting in a multimedia document a visible, or preferably invisible, mark to identify the owner.

  20. Optical replication techniques for image slicers

    Czech Academy of Sciences Publication Activity Database

    Schmoll, J.; Robertson, D.J.; Dubbeldam, C.M.; Bortoletto, F.; Pína, L.; Hudec, René; Prieto, E.; Norrie, C.; Ramsay- Howat, S.

    2006-01-01

    Roč. 50, 4-5 (2006), s. 263-266 ISSN 1387-6473 Institutional research plan: CEZ:AV0Z10030501 Keywords : smart focal planes * image slicers * replication Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.914, year: 2006

  1. Jet-images: computer vision inspired techniques for jet tagging

    International Nuclear Information System (INIS)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel

    2015-01-01

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  2. Jet-images: computer vision inspired techniques for jet tagging

    Energy Technology Data Exchange (ETDEWEB)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel [SLAC National Accelerator Laboratory,Menlo Park, CA 94028 (United States)

    2015-02-18

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  3. Hierarchical clustering techniques for image database organization and summarization

    Science.gov (United States)

    Vellaikal, Asha; Kuo, C.-C. Jay

    1998-10-01

    This paper investigates clustering techniques as a method of organizing image databases to support popular visual management functions such as searching, browsing and navigation. Different types of hierarchical agglomerative clustering techniques are studied as a method of organizing features space as well as summarizing image groups by the selection of a few appropriate representatives. Retrieval performance using both single and multiple level hierarchies are experimented with and the algorithms show an interesting relationship between the top k correct retrievals and the number of comparisons required. Some arguments are given to support the use of such cluster-based techniques for managing distributed image databases.

  4. Single photon imaging. New instrumentation and techniques

    International Nuclear Information System (INIS)

    Muehllehner, G.; Colsher, J.

    1981-01-01

    The performance of Anger scintillation cameras continues to be enhanced through a series of small improvements which result in significantly better imaging characteristics. The most recent changes in camera design consist of: (1) the introduction of photomultipliers with better photocathode and electron collection efficiencies, (2) the use of thinner (3/8 or 1/4 in) crystals giving slightly better intrinsic resolution for low gamma-ray energies, (3) inclusion of a spatially varying energy window to compensate for variations of light collection efficiency, (4) event-by-event, real-time distortion removal for uniformity correction, and (5) introduction of new methods to improve the count-rate capability. Whereas some of these improvements are due to better understanding of the fundamentals of camera design, others are the result of technological advances in electronic components such as analogue-to-digital converters, microprocessors and high-density digital memories. The development of single photon tomography has developed along two parallel paths. Multipinhole and rotating slant-hole collimator attachments provide some degree of longitudinal tomography, and are currently being applied to cardiac imaging. At the same time rotating camera systems capable of transverse as well as longitudinal imaging are being refined technically and evaluated clinically. Longitudinal tomography is of limited use in quantitative studies and is likely to be an interim solution to three-dimensional imaging. Rotating camera systems, on the other hand, not only provide equal resolution in all three dimensions but are also capable of providing quantitative accuracy. This is the result of progress in attenuation correction and the design of special collimators. Single photon tomography provides a small but noticeable improvement in diagnostic accuracy which is likely to result in widespread use of rotating camera systems in the future

  5. A review of imaging techniques for systems biology

    Directory of Open Access Journals (Sweden)

    Po Ming J

    2008-08-01

    Full Text Available Abstract This paper presents a review of imaging techniques and of their utility in system biology. During the last decade systems biology has matured into a distinct field and imaging has been increasingly used to enable the interplay of experimental and theoretical biology. In this review, we describe and compare the roles of microscopy, ultrasound, CT (Computed Tomography, MRI (Magnetic Resonance Imaging, PET (Positron Emission Tomography, and molecular probes such as quantum dots and nanoshells in systems biology. As a unified application area among these different imaging techniques, examples in cancer targeting are highlighted.

  6. Robust image modeling technique with a bioluminescence image segmentation application

    Science.gov (United States)

    Zhong, Jianghong; Wang, Ruiping; Tian, Jie

    2009-02-01

    A robust pattern classifier algorithm for the variable symmetric plane model, where the driving noise is a mixture of a Gaussian and an outlier process, is developed. The veracity and high-speed performance of the pattern recognition algorithm is proved. Bioluminescence tomography (BLT) has recently gained wide acceptance in the field of in vivo small animal molecular imaging. So that it is very important for BLT to how to acquire the highprecision region of interest in a bioluminescence image (BLI) in order to decrease loss of the customers because of inaccuracy in quantitative analysis. An algorithm in the mode is developed to improve operation speed, which estimates parameters and original image intensity simultaneously from the noise corrupted image derived from the BLT optical hardware system. The focus pixel value is obtained from the symmetric plane according to a more realistic assumption for the noise sequence in the restored image. The size of neighborhood is adaptive and small. What's more, the classifier function is base on the statistic features. If the qualifications for the classifier are satisfied, the focus pixel intensity is setup as the largest value in the neighborhood.Otherwise, it will be zeros.Finally,pseudo-color is added up to the result of the bioluminescence segmented image. The whole process has been implemented in our 2D BLT optical system platform and the model is proved.

  7. Employing image processing techniques for cancer detection using microarray images.

    Science.gov (United States)

    Dehghan Khalilabad, Nastaran; Hassanpour, Hamid

    2017-02-01

    Microarray technology is a powerful genomic tool for simultaneously studying and analyzing the behavior of thousands of genes. The analysis of images obtained from this technology plays a critical role in the detection and treatment of diseases. The aim of the current study is to develop an automated system for analyzing data from microarray images in order to detect cancerous cases. The proposed system consists of three main phases, namely image processing, data mining, and the detection of the disease. The image processing phase performs operations such as refining image rotation, gridding (locating genes) and extracting raw data from images the data mining includes normalizing the extracted data and selecting the more effective genes. Finally, via the extracted data, cancerous cell is recognized. To evaluate the performance of the proposed system, microarray database is employed which includes Breast cancer, Myeloid Leukemia and Lymphomas from the Stanford Microarray Database. The results indicate that the proposed system is able to identify the type of cancer from the data set with an accuracy of 95.45%, 94.11%, and 100%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. New approaches in intelligent image analysis techniques, methodologies and applications

    CERN Document Server

    Nakamatsu, Kazumi

    2016-01-01

    This book presents an Introduction and 11 independent chapters, which are devoted to various new approaches of intelligent image processing and analysis. The book also presents new methods, algorithms and applied systems for intelligent image processing, on the following basic topics: Methods for Hierarchical Image Decomposition; Intelligent Digital Signal Processing and Feature Extraction; Data Clustering and Visualization via Echo State Networks; Clustering of Natural Images in Automatic Image Annotation Systems; Control System for Remote Sensing Image Processing; Tissue Segmentation of MR Brain Images Sequence; Kidney Cysts Segmentation in CT Images; Audio Visual Attention Models in Mobile Robots Navigation; Local Adaptive Image Processing; Learning Techniques for Intelligent Access Control; Resolution Improvement in Acoustic Maps. Each chapter is self-contained with its own references. Some of the chapters are devoted to the theoretical aspects while the others are presenting the practical aspects and the...

  9. Technique development for photoacoustic imaging guided interventions

    Science.gov (United States)

    Cheng, Qian; Zhang, Haonan; Yuan, Jie; Feng, Ting; Xu, Guan; Wang, Xueding

    2015-03-01

    Laser-induced thermotherapy (LITT), i.e. tissue destruction induced by a local increase of temperature by means of laser light energy transmission, has been frequently used for minimally invasive treatments of various diseases such as benign thyroid nodules and liver cancer. The emerging photoacoustic (PA) imaging, when integrated with ultrasound (US), could contribute to LITT procedure. PA can enable a good visualization of percutaneous apparatus deep inside tissue and, therefore, can offer accurate guidance of the optical fibers to the target tissue. Our initial experiment demonstrated that, by picking the strong photoacoustic signals generated at the tips of optical fibers as a needle, the trajectory and position of the fibers could be visualized clearly using a commercial available US unit. When working the conventional US Bscan mode, the fibers disappeared when the angle between the fibers and the probe surface was larger than 60 degree; while working on the new PA mode, the fibers could be visualized without any problem even when the angle between the fibers and the probe surface was larger than 75 degree. Moreover, with PA imaging function integrated, the optical fibers positioned into the target tissue, besides delivering optical energy for thermotherapy, can also be used to generate PA signals for on-line evaluation of LITT. Powered by our recently developed PA physio-chemical analysis, PA measurements from the tissue can provide a direct and accurate feedback of the tissue responses to laser ablation, including the changes in not only chemical compositions but also histological microstructures. The initial experiment on the rat liver model has demonstrated the excellent sensitivity of PA imaging to the changes in tissue temperature rise and tissue status (from native to coagulated) when the tissue is treated in vivo with LITT.

  10. Evaluation of radiographic imaging techniques in lung nodule detection

    International Nuclear Information System (INIS)

    Ho, J.T.; Kruger, R.A.

    1989-01-01

    Dual-energy radiography appears to be the most effective technique to address bone superposition that compromises conventional chest radiography. A dual-energy, single-exposure, film-based technique was compared with a dual-energy, dual-exposure technique and conventional chest radiography in a simulated lung nodule detection study. Observers detected more nodules on images produced by dual-energy techniques than on images produced by conventional chest radiography. The difference between dual-energy and conventional chest radiography is statistically significant and the difference between dual-energy, dual-exposure and single-exposure techniques is statistically insignificant. The single-exposure technique has the potential to replace the dual-exposure technique in future clinical application

  11. New imaging techniques: principles, limitations and the question of cost

    Energy Technology Data Exchange (ETDEWEB)

    Marsault, C.; Heran, F.; Brugieres, P.; Le Bras, F.; Castrec-Carpo, A.

    1989-03-01

    The new imaging techniques modify the diagnostic, or even sometimes therapeutic, decision lines. Their efficiency is much greater than that of the old techniques, while pretium doloris and side-effects are considerably reduced. Such advances are not without a major disadvantage: the ever increasing cost of imaging explorations. Radiological guidance (with conventional radiology, ultrasounds and computerized tomography) facilitates percutaneous procedures for diagnostic (biopsy) or therapeutic purposes (emptying of abscesses, chemonucleolysis of herniated lumbar disc, etc.).

  12. An Image Registration Based Technique for Noninvasive Vascular Elastography

    OpenAIRE

    Valizadeh, Sina; Makkiabadi, Bahador; Mirbagheri, Alireza; Soozande, Mehdi; Manwar, Rayyan; Mozaffarzadeh, Moein; Nasiriavanaki, Mohammadreza

    2018-01-01

    Non-invasive vascular elastography is an emerging technique in vascular tissue imaging. During the past decades, several techniques have been suggested to estimate the tissue elasticity by measuring the displacement of the Carotid vessel wall. Cross correlation-based methods are the most prevalent approaches to measure the strain exerted in the wall vessel by the blood pressure. In the case of a low pressure, the displacement is too small to be apparent in ultrasound imaging, especially in th...

  13. 'Hybrid' non-destructive imaging techniques for engineering materials applications

    OpenAIRE

    2014-01-01

    The combination of X-ray imaging and diffraction techniques provides a unique tool for structural and mechanical analysis of engineering components. A variety of modes can be employed in terms of the spatial resolution (length-scale), time resolution (frequency), and the nature of the physical quantity being interrogated. This thesis describes my contributions towards the development of novel X-ray “rich” imaging experimental techniques and data interpretation. The experiment...

  14. Review of Leaf Unhealthy Region Detection Using Image Processing Techniques

    OpenAIRE

    A. Dhole, S; Shaikh, Rukaiyya Pyarelal

    2016-01-01

    - In agricultural field the plants comes to an attack from the various pets bacterial and micro-organism diseases. This diseases attacks on the plant leaves, steams, and fruit part. This present review paper discussed the image processing techniques which is used in performing the early detection of plant diseases through leaf feature inspection. the basic objective of this work is to develop image analysis and classification techniques for extraction and finally classified the diseases pre...

  15. CATEGORICAL IMAGE COMPONENTS IN THE FORMING SYSTEM OF A MARKETING TECHNIQUES MANAGER’S IMAGE CULTURE

    Directory of Open Access Journals (Sweden)

    Anna Borisovna Cherednyakova

    2015-08-01

    Full Text Available Based on the understanding of the image culture formation of managers of marketing techniques, as a representative of the social and communication interaction of public structures, categorical apparatus of image culture with an emphasis on the etymology of the image, as an integral component of image culture was analyzed. Categorical components of the image are presented from the standpoint of image culture, as personal new formation, an integral part of the professional activity of the marketing techniques manager: object-communicative categorical component, subject-activity categorical component of image, personality-oriented categorical component, value-acmeological categorical component of image.The aim is to identify and justify the image categorical components as a component of image culture of the marketing techniques manager.Method and methodology of work – a general scientific research approach reflecting scientific apparatus of research.Results. Categorical components of the image, as an image culture component of manager of marketing techniques were defined.Practical implication of the results. The theoretical part of «Imageology» course, special course «Image culture of manager of marketing techniques», the theoretical and methodological study and the formation of image culture.

  16. Application of digital-image-correlation techniques in analysing ...

    Indian Academy of Sciences (India)

    experimental results obtained using the digital image correlation analysis is used to demonstrate the crack development ... of applying DIC technique to monitor pipeline cracks is tested in this research by designing and applying a new test to be .... The appropriate sub-image size must be determined in accordance with the ...

  17. Application of digital image processing techniques to astronomical imagery 1978

    Science.gov (United States)

    Lorre, J. J.

    1978-01-01

    Techniques for using image processing in astronomy are identified and developed for the following: (1) geometric and radiometric decalibration of vidicon-acquired spectra, (2) automatic identification and segregation of stars from galaxies; and (3) display of multiband radio maps in compact and meaningful formats. Examples are presented of these techniques applied to a variety of objects.

  18. Muscle perfusion and metabolic heterogeneity: insights from noninvasive imaging techniques

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Scheede-Bergdahl, Celena; Kjaer, Michael

    2006-01-01

    Recent developments in noninvasive imaging techniques have enabled the study of local changes in perfusion and metabolism in skeletal muscle as well as patterns of heterogeneity in these variables in humans. In this review, the principles of these techniques along with some recent findings...

  19. Cardiovascular Imaging Techniques in Systemic Rheumatic Diseases

    Directory of Open Access Journals (Sweden)

    Fabiola Atzeni

    2018-02-01

    Full Text Available The risk of cardiovascular (CV events and mortality is significantly higher in patients with systemic rheumatic diseases than in the general population. Although CV involvement in such patients is highly heterogeneous and may affect various structures of the heart, it can now be diagnosed earlier and promptly treated. Various types of assessments are employed for the evaluation of CV risk such as transthoracic or transesophageal echocardiography, magnetic resonance imaging (MRI, and computed tomography (CT to investigate valve abnormalities, pericardial disease, and ventricular wall motion defects. The diameter of coronary arteries can be assessed using invasive quantitative coronarography or intravascular ultrasound, and coronary flow reserve can be assessed using non-invasive transesophageal or transthoracic ultrasonography (US, MRI, CT, or positron emission tomography (PET after endothelium-dependent vasodilation. Finally, peripheral circulation can be measured invasively using strain-gauge plethysmography in an arm after the arterial infusion of an endothelium-dependent vasodilator or non-invasively by means of US or MRI measurements of flow-mediated vasodilation of the brachial artery. All of the above are reliable methods of investigating CV involvement, but more recently, introduced use of speckle tracking echocardiography and 3-dimensional US are diagnostically more accurate.

  20. The new techniques of scintigraphic imaging

    International Nuclear Information System (INIS)

    Chatal, J.F.

    1990-01-01

    The purpose of scintigraphic imaging is not to explore the morphology of an organ (or its abnormalities) but rather its functional and metabolic characteristics. It is thus important that a molecular structure (e.g., a hormonal receptor or an antigen) closely linked to the functional activity of an organ or tissue be targeted on its cell surface. Such diagnostic targeting requires the synthesis and labeling of a radiopharmaceutical substance specific for the receptor or antigen in question. It also requires a detection system adapted to count rates and signal-to-background ratios (generally moderate). The synthesis of new radiopharmaceutical agents, a critical stage for the future of nuclear medicine, is a long and often risky process in which success is difficult to foresee. Radiolabeling must be stable in vitro and in vivo, and the radiopharmaceutical must subsequently retain its capability of recognizing the targeted molecule. In endocrinology, the exemplary achievement in this direction has been the synthesis of 131 I-6-iodomethylnorcholesterol and 131 I-metaiodobenzylguanidine for functional scintigraphy of the adrenal cortex and medulla. Progress in detection equipment has been marked by the development of monophotonic tomoscintigraphy, using gamma cameras with a revolving head to obtain slices in different spatial planes showing the distribution in the organism of the injected radiopharmaceutical agent [fr

  1. A Comparison of Speckle Reduction Techniques in Medical Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    Cristina STOLOJESCU-CRISAN

    2015-06-01

    Full Text Available Speckle noise is a multiplicative noise that degrades the visual evaluation in ultrasound imaging. In addition, it limits the efficient application of intelligent image processing algorithms, such as segmentation techniques. Thus, speckle noise reduction is considered an essential pre-processing step. The objective of this paper is to carry out a comparative evaluation of speckle filtering techniques, based on two image quality evaluation metrics, the Peak Signal to Noise Ratio (PSNR, and the Structural SIMilarity (SSIM index, and visual evaluation.

  2. A machine vision identification technique from range images

    Science.gov (United States)

    Kehtarnavaz, N.; Mohan, S.

    1988-01-01

    An orientation-independent identification technique from three-dimensional surface maps or range images is developed. Given the range image of an object, it is decomposed into orientation-independent patches using the sign of Gaussian curvature. A relational graph is then set up such that a node represents a patch and an edge represents the adjacency of two patches. The identification of the object is achieved by matching its graph representation to a number of model graphs. The matching is performed by employing the best-first search strategy. Examples of real range images show the merit of the technique.

  3. A fast iterative technique for restoring scanning electron microscope images

    Energy Technology Data Exchange (ETDEWEB)

    Nakahira, Kenji, E-mail: kenji.nakahira.kp@hitachi.com; Miyamoto, Atsushi; Honda, Toshifumi

    2014-12-21

    This paper proposes a fast new technique for restoring scanning electron microscope images to improve their sharpness. The images with our approach are sharpened by deconvolution with the point spread function modeled as the intensity distribution of the electron beam at the specimen's surface. We propose an iterative technique that employs a modified cost function based on the Richardson–Lucy method to achieve faster processing. The empirical results indicate significant improvements in image quality. The proposed approach speeds up deconvolution by about 10–50 times faster than that with the conventional Richardson–Lucy method.

  4. A Novel Contrast Enhancement Technique on Palm Bone Images

    Directory of Open Access Journals (Sweden)

    Yung-Tsang Chang

    2014-09-01

    Full Text Available Contrast enhancement plays a fundamental role in image processing. Many histogram-based techniques are widely used for contrast enhancement of given images, due to their simple function and effectiveness. However, the conventional histogram equalization (HE methods result in excessive contrast enhancement, which causes natural looking and satisfactory results for a variety of low contrast images. To solve such problems, a novel multi-histogram equalization technique is proposed to enhance the contrast of the palm bone X-ray radiographs in this paper. For images, the mean-variance analysis method is employed to partition the histogram of the original grey scale image into multiple sub-histograms. These histograms are independently equalized. By using this mean-variance partition method, a proposed multi-histogram equalization technique is employed to achieve the contrast enhancement of the palm bone X-ray radiographs. Experimental results show that the multi-histogram equalization technique achieves a lower average absolute mean brightness error (AMBE value. The multi-histogram equalization technique simultaneously preserved the mean brightness and enhanced the local contrast of the original image.

  5. A Blind High-Capacity Wavelet-Based Steganography Technique for Hiding Images into other Images

    Directory of Open Access Journals (Sweden)

    HAMAD, S.

    2014-05-01

    Full Text Available The flourishing field of Steganography is providing effective techniques to hide data into different types of digital media. In this paper, a novel technique is proposed to hide large amounts of image data into true colored images. The proposed method employs wavelet transforms to decompose images in a way similar to the Human Visual System (HVS for more secure and effective data hiding. The designed model can blindly extract the embedded message without the need to refer to the original cover image. Experimental results showed that the proposed method outperformed all of the existing techniques not only imperceptibility but also in terms of capacity. In fact, the proposed technique showed an outstanding performance on hiding a secret image whose size equals 100% of the cover image while maintaining excellent visual quality of the resultant stego-images.

  6. A contrast enhancement technique for low light images

    Science.gov (United States)

    Singh, Ankita; Gupta, K. K.

    2016-03-01

    Digital Imagery systems are traditionally bad in low light conditions. In this paper, a new algorithm for contrast improvement is proposed. The algorithm consists of two stages. The first stage is decomposing the input image into four subbands by applying two-dimensional discrete wavelet transform and estimates the singular value matrix of sub band image. The second stage is that it reconstructs the enhanced image by applying the inverse DWT. The technique is compared with conventional image equalization technique such as standard General Histogram Equalization (GHE) and other state-of-the-art techniques such as Quadrant Dynamic Histogram Equalization (QDHE), Singular-Value-Wavelet based image Equalization (SVWE) and Singular Value Equalization (SVE) on the basis of their Peak Signal to Noise Ratio (PSNR) and Root Mean Square Error (RMSE) values. The simulation results indicated that the image contrast enhanced by the purposed method was higher than that of the images enhanced by the other conventional state-of-the-art techniques.

  7. Introduction to basic molecular biologic techniques for molecular imaging researches

    International Nuclear Information System (INIS)

    Kang, Joo Hyun

    2004-01-01

    Molecular imaging is a rapidly growing field due to the advances in molecular biology and imaging technologies. With the introduction of imaging reporter genes into the cell, diverse cellular processes can be monitored, quantified and imaged non-invasively in vivo. These processes include the gene expression, protein-protein interactions, signal transduction pathways, and monitoring of cells such as cancer cells, immune cells, and stem cells. In the near future, molecular imaging analysis will allow us to observe the incipience and progression of the disease. These will make us easier to give a diagnosis in the early stage of intractable diseases such as cancer, neuro-degenerative disease, and immunological disorders. Additionally, molecular imaging method will be a valuable tool for the real-time evaluation of cells in molecular biology and the basic biological studies. As newer and more powerful molecular imaging tools become available, it will be necessary to corporate clinicians, molecular biologists and biochemists for the planning, interpretation, and application of these techniques to their fullest potential. In order for such a multidisciplinary team to be effective, it is essential that a common understanding of basic biochemical and molecular biologic techniques is achieved. Basic molecular techniques for molecular imaging methods are presented in this paper

  8. Imaging of mass distribution in paper by electrography technique, (2)

    International Nuclear Information System (INIS)

    Tomimasu, Hiroshi; Luner, P.

    1991-01-01

    Four paper imaging techniques (β-radiography, electrography, light transmission, and soft x-radiography) were compared in terms of their process parameters and image characteristics (exposure time, spatial variation, contrast, spatial resolution, correlation with mass, and limitation in basis weight range) with the same newsprint sample and electron microscope film. As far as the imaging conditions chosen here are concerned, electrography gave a higher spatial resolution, shorter exposure time, and the wider basis weight range than β-radiography. Light transmission image could be obtained in a very short time, but gave the poorest spatial resolution and correlation with mass. Soft x-radiography gave the highest spatial resolution, but the poorest spatial variation and contrast. The proper imaging technique and conditions need to be selected depending on the specific paper property in question. (author)

  9. Imaging of laboratory magnetospheric plasmas using coherence imaging technique

    Science.gov (United States)

    Nishiura, Masaki; Takahashi, Noriki; Yoshida, Zensho; Nakamura, Kaori; Kawazura, Yohei; Kenmochi, Naoki; Nakatsuka, Masataka; Sugata, Tetsuya; Katsura, Shotaro; Howard, John

    2017-10-01

    The ring trap 1 (RT-1) device creates a laboratory magnetosphere for the studies on plasma physics and advanced nuclear fusion. A levitated superconducting coil produces magnetic dipole fields that realize a high beta plasma confinement that is motivated by self-organized plasmas in planetary magnetospheres. The electron cyclotron resonance heating (ECRH) with 8.2 GHz and 50 kW produces the plasmas with hot electrons in a few ten keV range. The electrons contribute to the local electron beta that exceeded 1 in RT-1. For the ion heating, ion cyclotron range of frequencies (ICRF) heating with 2-4 MHz and 10 kW has been performed in RT-1. The radial profile of ion temperature by a spectroscopic measurement indicates the signature of ion heating. In the holistic point of view, a coherence imaging system has been implemented for imaging the entire ion dynamics in the laboratory magnetosphere. The diagnostic system and obtained results will be presented.

  10. Chest trauma in children: current imaging guidelines and techniques.

    LENUS (Irish Health Repository)

    Moore, Michael A

    2011-09-01

    Given the heterogeneous nature of pediatric chest trauma, the optimal imaging approach is tailored to the specific patient. Chest radiography remains the most important imaging modality for initial triage. The decision to perform a chest computed tomography scan should be based on the nature of the trauma, the child\\'s clinical condition, and the initial radiographic findings, taking the age-related pretest probabilities of serious injury into account. The principles of as low as reasonably achievable and Image Gently should be followed. The epidemiology and pathophysiology, imaging techniques, characteristic findings, and evidence-based algorithms for pediatric chest trauma are discussed.

  11. An Image Morphing Technique Based on Optimal Mass Preserving Mapping

    Science.gov (United States)

    Zhu, Lei; Yang, Yan; Haker, Steven; Tannenbaum, Allen

    2013-01-01

    Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The L2 mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods. PMID:17547128

  12. Digital signal processing techniques and applications in radar image processing

    CERN Document Server

    Wang, Bu-Chin

    2008-01-01

    A self-contained approach to DSP techniques and applications in radar imagingThe processing of radar images, in general, consists of three major fields: Digital Signal Processing (DSP); antenna and radar operation; and algorithms used to process the radar images. This book brings together material from these different areas to allow readers to gain a thorough understanding of how radar images are processed.The book is divided into three main parts and covers:* DSP principles and signal characteristics in both analog and digital domains, advanced signal sampling, and

  13. A Document Imaging Technique for Implementing Electronic Loan Approval Process

    Directory of Open Access Journals (Sweden)

    J. Manikandan

    2015-04-01

    Full Text Available The image processing is one of the leading technologies of computer applications. Image processing is a type of signal processing, the input for image processor is an image or video frame and the output will be an image or subset of image [1]. Computer graphics and computer vision process uses an image processing techniques. Image processing systems are used in various environments like medical fields, computer-aided design (CAD, research fields, crime investigation fields and military fields. In this paper, we proposed a document image processing technique, for establishing electronic loan approval process (E-LAP [2]. Loan approval process has been tedious process, the E-LAP system attempts to reduce the complexity of loan approval process. Customers have to login to fill the loan application form online with all details and submit the form. The loan department then processes the submitted form and then sends an acknowledgement mail via the E-LAP to the requested customer with the details about list of documents required for the loan approval process [3]. The approaching customer can upload the scanned copies of all required documents. All this interaction between customer and bank take place using an E-LAP system.

  14. [X-ray radiographic imaging technique with high dynamic range].

    Science.gov (United States)

    Liu, Bin; Wang, Li-Ming; Su, Xin-Yan

    2014-04-01

    In conventional X-ray radiographic imaging system with a fixed energy parameter, the acquired X-ray images are usually overexposed and have no useful information available. It is due to some constraints, like special structure of component, different attenuation coefficients of materials and dynamic range of optoelectronic devices. When maximum of transmitted X-ray luminous exceed capacity limitation of X-ray radiographic imaging system in one scene, the device up to saturate. Also when minimum of transmitted X-ray luminous is below the thermal noise level of imaging system, no useful information is available for imaging. To solve the problem of difficulties in acquiring transmitted X-ray luminous in a wide dynamic range by conventional X-ray radiographic imaging system, we put forward a new X-ray radiographic imaging technique with high dynamic range based on adjusting tube voltage. In the article, the influence by charge capacity of X-ray radiographic imaging system on effective irradiating thickness is analyzed. Through experiments of some standard samples, we gained the relationship between voltage range of X-ray tube and materials or structure of component for best testing sensitivity. Then we put forward an adjusting strategy of tube voltage and effective subgraphs extraction method from acquired raw X-ray images. By the mentioned method, we carried out X-ray radiographic imaging experiments with high dynamic range for components with thickness from 0 to 20 mm. The results show that X-ray radiographic imaging technique with high dynamic range is effective to realize imaging for some components with different thickness. It is available for us to find more detailed projection information from fusion images.

  15. Cartilage imaging: motivation, techniques, current and future significance

    International Nuclear Information System (INIS)

    Link, Thomas M.; Stahl, Robert; Woertler, Klaus

    2007-01-01

    Cartilage repair techniques and pharmacological therapies are currently areas of major clinical interest and research, in particular to prevent and treat osteoarthritis. MR imaging-based techniques to visualize cartilage are prerequisites to guide and monitor these therapies. In this review article, standard MR imaging sequences are described, including proton density-weighted fast spin echo, spoiled gradient echo and dual echo steady state sequences. In addition, new sequences that have been developed and are currently being investigated are presented, including driven equilibrium Fourier transform and steady-state free precession-based imaging. Using high-field MR imaging at 3.0-T, visualization of cartilage and the related pathology has been improved. Volumetric quantitative cartilage MR imaging was developed as a tool to monitor the progression of osteoarthritis and to evaluate new pharmacological cartilage protective therapies. The most exciting developments, however, are in the field of cartilage matrix assessment with quantitative dGEMRIC, T2 and T1rho mapping techniques. These techniques aim at detecting cartilage damage at a stage when changes are potentially still reversible, before cartilage tissue is lost. There is currently substantial interest in these techniques from rheumatologists and orthopedists; radiologists therefore need to keep up with these developments. (orig.)

  16. Pattern recognition software and techniques for biological image analysis.

    Directory of Open Access Journals (Sweden)

    Lior Shamir

    2010-11-01

    Full Text Available The increasing prevalence of automated image acquisition systems is enabling new types of microscopy experiments that generate large image datasets. However, there is a perceived lack of robust image analysis systems required to process these diverse datasets. Most automated image analysis systems are tailored for specific types of microscopy, contrast methods, probes, and even cell types. This imposes significant constraints on experimental design, limiting their application to the narrow set of imaging methods for which they were designed. One of the approaches to address these limitations is pattern recognition, which was originally developed for remote sensing, and is increasingly being applied to the biology domain. This approach relies on training a computer to recognize patterns in images rather than developing algorithms or tuning parameters for specific image processing tasks. The generality of this approach promises to enable data mining in extensive image repositories, and provide objective and quantitative imaging assays for routine use. Here, we provide a brief overview of the technologies behind pattern recognition and its use in computer vision for biological and biomedical imaging. We list available software tools that can be used by biologists and suggest practical experimental considerations to make the best use of pattern recognition techniques for imaging assays.

  17. Radiation-Based Medical Imaging Techniques: An Overview

    Science.gov (United States)

    Prior, John O.; Lecoq, Paul

    This chapter will present an overview of two radiation-based medical imaging techniques using radiopharmaceuticals used in nuclear medicine/molecular imaging, namely, single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The relative merits in terms of radiation sensitivity and image resolution of SPECT and PET will be compared to the main conventional radiologic modalities that are computed tomography (CT) and magnetic resonance (MR) imaging. Differences in terms of temporal resolution will also be outlined, as well as the other similarities and dissimilarities of these two techniques, including their latest and upcoming multimodality combination. The main clinical applications are briefly described and examples of specific SPECT and PET radiopharmaceuticals are listed. SPECT and PET imaging will be then further detailed in the two subsequent chapters describing in greater depth the basics and future trends of each technique (see Chaps. 37, "SPECT Imaging: Basics and New Trends" 10.1007/978-3-642-13271-1_37 and 38, "PET Imaging: Basics and New Trends" 10.1007/978-3-642-13271-1_38.

  18. Video Multiple Watermarking Technique Based on Image Interlacing Using DWT

    Directory of Open Access Journals (Sweden)

    Mohamed M. Ibrahim

    2014-01-01

    Full Text Available Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  19. MICROARRAY IMAGE GRIDDING USING GRID LINE REFINEMENT TECHNIQUE

    Directory of Open Access Journals (Sweden)

    V.G. Biju

    2015-05-01

    Full Text Available An important stage in microarray image analysis is gridding. Microarray image gridding is done to locate sub arrays in a microarray image and find co-ordinates of spots within each sub array. For accurate identification of spots, most of the proposed gridding methods require human intervention. In this paper a fully automatic gridding method which enhances spot intensity in the preprocessing step as per a histogram based threshold method is used. The gridding step finds co-ordinates of spots from horizontal and vertical profile of the image. To correct errors due to the grid line placement, a grid line refinement technique is proposed. The algorithm is applied on different image databases and results are compared based on spot detection accuracy and time. An average spot detection accuracy of 95.06% depicts the proposed method’s flexibility and accuracy in finding the spot co-ordinates for different database images.

  20. Spatial Angular Compounding Technique for H-Scan Ultrasound Imaging.

    Science.gov (United States)

    Khairalseed, Mawia; Xiong, Fangyuan; Kim, Jung-Whan; Mattrey, Robert F; Parker, Kevin J; Hoyt, Kenneth

    2018-01-01

    H-Scan is a new ultrasound imaging technique that relies on matching a model of pulse-echo formation to the mathematics of a class of Gaussian-weighted Hermite polynomials. This technique may be beneficial in the measurement of relative scatterer sizes and in cancer therapy, particularly for early response to drug treatment. Because current H-scan techniques use focused ultrasound data acquisitions, spatial resolution degrades away from the focal region and inherently affects relative scatterer size estimation. Although the resolution of ultrasound plane wave imaging can be inferior to that of traditional focused ultrasound approaches, the former exhibits a homogeneous spatial resolution throughout the image plane. The purpose of this study was to implement H-scan using plane wave imaging and investigate the impact of spatial angular compounding on H-scan image quality. Parallel convolution filters using two different Gaussian-weighted Hermite polynomials that describe ultrasound scattering events are applied to the radiofrequency data. The H-scan processing is done on each radiofrequency image plane before averaging to get the angular compounded image. The relative strength from each convolution is color-coded to represent relative scatterer size. Given results from a series of phantom materials, H-scan imaging with spatial angular compounding more accurately reflects the true scatterer size caused by reductions in the system point spread function and improved signal-to-noise ratio. Preliminary in vivo H-scan imaging of tumor-bearing animals suggests this modality may be useful for monitoring early response to chemotherapeutic treatment. Overall, H-scan imaging using ultrasound plane waves and spatial angular compounding is a promising approach for visualizing the relative size and distribution of acoustic scattering sources. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

  1. Unsupervised color image segmentation using a lattice algebra clustering technique

    Science.gov (United States)

    Urcid, Gonzalo; Ritter, Gerhard X.

    2011-08-01

    In this paper we introduce a lattice algebra clustering technique for segmenting digital images in the Red-Green- Blue (RGB) color space. The proposed technique is a two step procedure. Given an input color image, the first step determines the finite set of its extreme pixel vectors within the color cube by means of the scaled min-W and max-M lattice auto-associative memory matrices, including the minimum and maximum vector bounds. In the second step, maximal rectangular boxes enclosing each extreme color pixel are found using the Chebychev distance between color pixels; afterwards, clustering is performed by assigning each image pixel to its corresponding maximal box. The two steps in our proposed method are completely unsupervised or autonomous. Illustrative examples are provided to demonstrate the color segmentation results including a brief numerical comparison with two other non-maximal variations of the same clustering technique.

  2. Results on plasma temperature measurement using an image processing technique

    Directory of Open Access Journals (Sweden)

    B. Mahdavipour

    Full Text Available Image processing technique (IPT is a computational technique which is a simple, wide and great for many purposes. In this paper, we used IPT to obtain plasma source such as sun and sunspot temperatures. Sun image was taken by a telescope and DSLR camera and imported to MATLAB software. Using the IPT, we cropped two areas and evaluated their RGB values, using a code which was written according to Python software. We computed wavelengths and then by substituting wavelengths in Wien’s law, we obtained sun’s surface and sunspot temperature’s. The temperature errors for surface and sunspot were 0.57% and 13% respectively. Keywords: Image processing technique, Plasma temperature

  3. Imaging of the hip and bony pelvis. Techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Davies, A.M. [Royal Orthopaedic Hospital, Birmingham (United Kingdom). MRI Centre; Johnson, K.J. [Princess of Wales Birmingham Children' s Hospital (United Kingdom); Whitehouse, R.W. (eds.) [Manchester Royal Infirmary (United Kingdom). Dept. of Clinical Radiology

    2006-07-01

    This is a comprehensive textbook on imaging of the bony pelvis and hip joint that provides a detailed description of the techniques and imaging findings relevant to this complex anatomical region. In the first part of the book, the various techniques and procedures employed for imaging the pelvis and hip are discussed in detail. The second part of the book documents the application of these techniques to the diverse clinical problems and diseases encountered. Among the many topics addressed are congenital and developmental disorders including developmental dysplasia of the hip, irritable hip and septic arthritis, Perthes' disease and avascular necrosis, slipped upper femoral epiphysis, bony and soft tissue trauma, arthritis, tumours and hip prostheses. Each chapter is written by an acknowledged expert in the field, and a wealth of illustrative material is included. This book will be of great value to musculoskeletal and general radiologists, orthopaedic surgeons and rheumatologists. (orig.)

  4. Electromagnetic considerations for RF current density imaging [MRI technique].

    Science.gov (United States)

    Scott, G C; Joy, M G; Armstrong, R L; Henkelman, R M

    1995-01-01

    Radio frequency current density imaging (RF-CDI) is a recent MRI technique that can image a Larmor frequency current density component parallel to B(0). Because the feasibility of the technique was demonstrated only for homogeneous media, the authors' goal here is to clarify the electromagnetic assumptions and field theory to allow imaging RF currents in heterogeneous media. The complete RF field and current density imaging problem is posed. General solutions are given for measuring lab frame magnetic fields from the rotating frame magnetic field measurements. For the general case of elliptically polarized fields, in which current and magnetic field components are not in phase, one can obtain a modified single rotation approximation. Sufficient information exists to image the amplitude and phase of the RF current density parallel to B(0) if the partial derivative in the B(0) direction of the RF magnetic field (amplitude and phase) parallel to B(0) is much smaller than the corresponding current density component. The heterogeneous extension was verified by imaging conduction and displacement currents in a phantom containing saline and pure water compartments. Finally, the issues required to image eddy currents are presented. Eddy currents within a sample will distort both the transmitter coil reference system, and create measurable rotating frame magnetic fields. However, a three-dimensional electro-magnetic analysis will be required to determine how the reference system distortion affects computed eddy current images.

  5. A human visual based binarization technique for histological images

    Science.gov (United States)

    Shreyas, Kamath K. M.; Rajendran, Rahul; Panetta, Karen; Agaian, Sos

    2017-05-01

    In the field of vision-based systems for object detection and classification, thresholding is a key pre-processing step. Thresholding is a well-known technique for image segmentation. Segmentation of medical images, such as Computed Axial Tomography (CAT), Magnetic Resonance Imaging (MRI), X-Ray, Phase Contrast Microscopy, and Histological images, present problems like high variability in terms of the human anatomy and variation in modalities. Recent advances made in computer-aided diagnosis of histological images help facilitate detection and classification of diseases. Since most pathology diagnosis depends on the expertise and ability of the pathologist, there is clearly a need for an automated assessment system. Histological images are stained to a specific color to differentiate each component in the tissue. Segmentation and analysis of such images is problematic, as they present high variability in terms of color and cell clusters. This paper presents an adaptive thresholding technique that aims at segmenting cell structures from Haematoxylin and Eosin stained images. The thresholded result can further be used by pathologists to perform effective diagnosis. The effectiveness of the proposed method is analyzed by visually comparing the results to the state of art thresholding methods such as Otsu, Niblack, Sauvola, Bernsen, and Wolf. Computer simulations demonstrate the efficiency of the proposed method in segmenting critical information.

  6. Osteonecrosis of the sesamoid bone: contribution of modern imaging techniques

    International Nuclear Information System (INIS)

    Leleu, J.P.; Heno, P.; Rispal, P.; Joullie, M.; Laurent, F.

    1990-01-01

    We report a case of osteonecrosis of the sesamoid bone or Renander disease in a young male serviceman. Modern imaging techniques proved useful for identifying the lesion. CT scan and above all magnetic resonance imaging established the accurate diagnosis. The combination of a hypointense signal from the sesamoid bone with an effusion in the first metatarsophalangeal joint should be considered as characteristic of osteonecrosis of the sesamoid bone [fr

  7. Assessment of banana fruit maturity by image processing technique

    OpenAIRE

    Surya Prabha, D.; Satheesh Kumar, J.

    2013-01-01

    Maturity stage of fresh banana fruit is an important factor that affects the fruit quality during ripening and marketability after ripening. The ability to identify maturity of fresh banana fruit will be a great support for farmers to optimize harvesting phase which helps to avoid harvesting either under-matured or over-matured banana. This study attempted to use image processing technique to detect the maturity stage of fresh banana fruit by its color and size value of their images precisely...

  8. Detection of Glaucoma Using Image Processing Techniques: A Critique.

    Science.gov (United States)

    Kumar, B Naveen; Chauhan, R P; Dahiya, Nidhi

    2018-01-01

    The primary objective of this article is to present a summary of different types of image processing methods employed for the detection of glaucoma, a serious eye disease. Glaucoma affects the optic nerve in which retinal ganglion cells become dead, and this leads to loss of vision. The principal cause is the increase in intraocular pressure, which occurs in open-angle and angle-closure glaucoma, the two major types affecting the optic nerve. In the early stages of glaucoma, no perceptible symptoms appear. As the disease progresses, vision starts to become hazy, leading to blindness. Therefore, early detection of glaucoma is needed for prevention. Manual analysis of ophthalmic images is fairly time-consuming and accuracy depends on the expertise of the professionals. Automatic analysis of retinal images is an important tool. Automation aids in the detection, diagnosis, and prevention of risks associated with the disease. Fundus images obtained from a fundus camera have been used for the analysis. Requisite pre-processing techniques have been applied to the image and, depending upon the technique, various classifiers have been used to detect glaucoma. The techniques mentioned in the present review have certain advantages and disadvantages. Based on this study, one can determine which technique provides an optimum result.

  9. [Application of image processing technique in scoliosis detection].

    Science.gov (United States)

    Lu, Donghui; Xu, Chaojing; Sun, Jinai

    2012-08-01

    Scoliosis, the abnormal lateral curvature of the spine, is an idiopathic disease often suffered by teenagers. Normally medical doctors use X-rays to measure the Cobb angle, and then assess the severity of scoliosis with it. In this paper, we point out the superiorities of image processing technique through analyzing the existing methods in the diagnosis of scoliosis. Two kinds of image processing technique are mainly introduced for scoliosis detection. The moiré stripe images show an asymmetric deformation pattern between the left-hand side and the right-hand side of human back, and these associate with Cobb angle to detect scoliosis. In order to check scoliosis through accurate three-dimensional surface features of human back, we in the second technique use different optical imaging methods to reconstruct the three-dimensional surface model of the patient's back, and extract the characteristics of the reconstructive human back to diagnose the disease. Both approaches tried to describe symmetry discrimination of human back and correlated it with the Cobb angles. Finally, we look forward to the future development in the application of image processing technique for scoliosis detection.

  10. Cherenkov imaging and timing techniques in astroparticle physics

    International Nuclear Information System (INIS)

    Spiering, C.

    1996-01-01

    Cherenkov techniques are widely used in astroparticle physics experiments. Classical ring imaging has been applied in balloon experiments. Underground Cherenkov detectors also yield ring-like patterns of photomultiplier hits, whereas in deep underwater experiments tracks are reconstructed from the light arrival times at photomultipliers spread over a large volume. Cherenkov air shower detectors either analyze the image of extended showers, or sample the arrival times of the Cherenkov light cone at different points at the earth's surface. This report reviews the various techniques and illustrates them by selected physics results. (orig.)

  11. Results on plasma temperature measurement using an image processing technique

    Science.gov (United States)

    Mahdavipour, B.; Hatami, A.; Salar Elahi, A.

    Image processing technique (IPT) is a computational technique which is a simple, wide and great for many purposes. In this paper, we used IPT to obtain plasma source such as sun and sunspot temperatures. Sun image was taken by a telescope and DSLR camera and imported to MATLAB software. Using the IPT, we cropped two areas and evaluated their RGB values, using a code which was written according to Python software. We computed wavelengths and then by substituting wavelengths in Wien's law, we obtained sun's surface and sunspot temperature's. The temperature errors for surface and sunspot were 0.57% and 13% respectively.

  12. Prognostic aspects on the development of imaging techniques

    International Nuclear Information System (INIS)

    Biehl, H.

    1985-01-01

    The development of imaging techniques designed for medical diagnostics and their application within the health service system are forecast up to the year 2000. The changes in the structure of the imaging methods that are to be expected in the GDR are outlined. Considering the users' needs and demands to be met by the manufacturers, in the long-term forecast it is dealt with more specifically with X-ray techniques, computer tomography, ultrasonic diagnostics, video endoscopy and the use of expert systems. (author)

  13. Terahertz spectroscopy and imaging – Modern techniques and applications

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd; Cooke, David; Koch, Martin

    2011-01-01

    Over the past three decades a new spectroscopic technique with unique possibilities has emerged. Based on coherent and time-resolved detection of the electric field of ultrashort radiation bursts in the far-infrared, this technique has become known as terahertz time-domain spectroscopy (THz......-TDS). In this review article the authors describe the technique in its various implementations for static and time-resolved spectroscopy, and illustrate the performance of the technique with recent examples from solid-state physics and physical chemistry as well as aqueous chemistry. Examples from other fields...... of research, where THz spectroscopic techniques have proven to be useful research tools, and the potential for industrial applications of THz spectroscopic and imaging techniques are discussed....

  14. improvement of digital image watermarking techniques based on FPGA implementation

    International Nuclear Information System (INIS)

    EL-Hadedy, M.E

    2006-01-01

    digital watermarking provides the ownership of a piece of digital data by marking the considered data invisibly or visibly. this can be used to protect several types of multimedia objects such as audio, text, image and video. this thesis demonstrates the different types of watermarking techniques such as (discrete cosine transform (DCT) and discrete wavelet transform (DWT) and their characteristics. then, it classifies these techniques declaring their advantages and disadvantages. an improved technique with distinguished features, such as peak signal to noise ratio ( PSNR) and similarity ratio (SR) has been introduced. the modified technique has been compared with the other techniques by measuring heir robustness against differ attacks. finally, field programmable gate arrays (FPGA) based implementation and comparison, for the proposed watermarking technique have been presented and discussed

  15. Magnetic resonance imaging of the elbow. Part I: Normal anatomy, imaging technique, and osseous abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Kijowski, Richard; Tuite, Michael; Sanford, Matthew [University of Wisconsin Hospital, Department of Radiology, Madison, Wisconsin (United States)

    2004-12-01

    Part I of this comprehensive review on magnetic resonance imaging of the elbow discusses normal elbow anatomy and the technical factors involved in obtaining high-quality magnetic resonance images of the elbow. Part I also discusses the role of magnetic resonance imaging in evaluating patients with osseous abnormalities of the elbow. With proper patient positioning and imaging technique, magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the osseous structures of the elbow. Magnetic resonance imaging can detect early osteochondritis dissecans of the capitellum and can be used to evaluate the size, location, stability, and viability of the osteochondritis dissecans fragment. Magnetic resonance imaging can detect early stress injury to the proximal ulna in athletes. Magnetic resonance imaging can detect radiographically occult fractures of the elbow in both children and adults. Magnetic resonance imaging is also useful in children to further evaluate elbow fractures which are detected on plain-film radiographs. (orig.)

  16. Image analysis techniques for the study of turbulent flows

    Science.gov (United States)

    Ferrari, Simone

    In this paper, a brief review of Digital Image Analysis techniques employed in Fluid Mechanics for the study of turbulent flows is given. Particularly the focus is on the techniques developed by the research teams the Author worked in, that can be considered relatively "low cost" techniques. Digital Image Analysis techniques have the advantage, when compared to the traditional techniques employing physical point probes, to be non-intrusive and quasi-continuous in space, as every pixel on the camera sensor works as a single probe: consequently, they allow to obtain two-dimensional or three-dimensional fields of the measured quantity in less time. Traditionally, the disadvantages are related to the frequency of acquisition, but modern high-speed cameras are typically able to acquire at frequencies from the order of 1 KHz to the order of 1 MHz. Digital Image Analysis techniques can be employed to measure concentration, temperature, position, displacement, velocity, acceleration and pressure fields with similar equipment and setups, and can be consequently considered as a flexible and powerful tool for measurements on turbulent flows.

  17. Image analysis techniques for the study of turbulent flows

    Directory of Open Access Journals (Sweden)

    Ferrari Simone

    2017-01-01

    Full Text Available In this paper, a brief review of Digital Image Analysis techniques employed in Fluid Mechanics for the study of turbulent flows is given. Particularly the focus is on the techniques developed by the research teams the Author worked in, that can be considered relatively “low cost” techniques. Digital Image Analysis techniques have the advantage, when compared to the traditional techniques employing physical point probes, to be non-intrusive and quasi-continuous in space, as every pixel on the camera sensor works as a single probe: consequently, they allow to obtain two-dimensional or three-dimensional fields of the measured quantity in less time. Traditionally, the disadvantages are related to the frequency of acquisition, but modern high-speed cameras are typically able to acquire at frequencies from the order of 1 KHz to the order of 1 MHz. Digital Image Analysis techniques can be employed to measure concentration, temperature, position, displacement, velocity, acceleration and pressure fields with similar equipment and setups, and can be consequently considered as a flexible and powerful tool for measurements on turbulent flows.

  18. A Kalman filter technique applied for medical image reconstruction

    International Nuclear Information System (INIS)

    Goliaei, S.; Ghorshi, S.; Manzuri, M. T.; Mortazavi, M.

    2011-01-01

    Medical images contain information about vital organic tissues inside of human body and are widely used for diagnoses of disease or for surgical purposes. Image reconstruction is essential for medical images for some applications such as suppression of noise or de-blurring the image in order to provide images with better quality and contrast. Due to vital rule of image reconstruction in medical sciences the corresponding algorithms with better efficiency and higher speed is desirable. Most algorithms in image reconstruction are operated on frequency domain such as the most popular one known as filtered back projection. In this paper we introduce a Kalman filter technique which is operated in time domain for medical image reconstruction. Results indicated that as the number of projection increases in both normal collected ray sum and the collected ray sum corrupted by noise the quality of reconstructed image becomes better in terms of contract and transparency. It is also seen that as the number of projection increases the error index decreases.

  19. Receiver Function Imaging of Dipping Structures - Technique and Applications

    Science.gov (United States)

    Liu, H.; Niu, F.

    2010-12-01

    CCP Stacking is probably the most common technique in receiver function imaging. In this technique, the conversion points are calculated and binned by assuming horizontal interfaces. However, for dipping structures such as tilted Moho or subducting slab, the horizontal interface assumption breaks down so that the image quality is low and the interfaces are misplaced. In these cases, the CCP stacking is not effective because the true conversion points do not necessarily lie in the vertical planes defined by sources and receivers and the delay time of conversion signals are varying with back azimuth. Although pre-stack time migration is an ideal technique to make correct images, the amount of qualified data it requires is often not available. An alternative way is to gather receiver functions based on conversion points and conversion times calculated from 3D velocity models with dipping structures. A dipping interface is defined by depth (d0) at a fixed geographic location, strike (Φ) and dipping angle (α). For an assumed (d0, Φ, α), we computed the conversion locations and conversion times by 3D ray tracing. We varied the depth (d0) and the dipping geometry (Φ, α) in certain range and determined the optimum value that gives the best coherent stacking signals. Note based on different tectonic setting, one or both of the dipping parameters can be fixed in the grid searching. We applied this technique to the imaging of two different geologic structures. One is a subducting slab case in western Mexico where the Rivera plate is subducting under the North American plate. Receiver functions recorded by fifty broadband seismic stations deployed under the MARS project were used to image the subducting Rivera slab. The second case is a tilted Moho lying underneath the GSN station SDV located at the southern flank of the central Venezuelan Andes. In both cases, we found substantial improvements in the receiver function images using our 3D ray tracing technique.

  20. Sampling-image streak framing technique and its special streak image tube

    CERN Document Server

    Ji Lili; Lan Zhou Jun; Yang, Q L; Zhang, H; Niu, H

    2002-01-01

    We designed a special electrostatic focusing streak image tube (SIT) with large magnification, tiny temporal distortion and large dynamic range for the application of the technique of sampling-image streaking frame (SISF) for plasma diagnostics in ICF. A proof-of-principle experiment of the technique is performed with the SIT, together with a picosecond laser and image reconstruction software. Using the digital image-processing program, the result gives 16 frames with an exposure time of better than 6.3 ps.

  1. Wavelet techniques for reversible data embedding into images

    NARCIS (Netherlands)

    L. Kamstra; H.J.A.M. Heijmans (Henk)

    2004-01-01

    textabstractThe proliferation of digital information in our society has enticed a lot of research into data embedding techniques that add information to digital content like images, audio and video. This additional information can be used for various purposes and different applications place

  2. Applying the digital-image-correlation technique to measure the ...

    Indian Academy of Sciences (India)

    It has been applied for analysing various structural problems. For exam- ple, French scholars Raffard et ... observe the crack development in masonry wall. One major advantage of DIC technique ... based on the characteristic gray-scale distributions in the image of the structural speckle on the specimen surface. As shown in ...

  3. Assessing clutter reduction in parallel coordinates using image processing techniques

    Science.gov (United States)

    Alhamaydh, Heba; Alzoubi, Hussein; Almasaeid, Hisham

    2018-01-01

    Information visualization has appeared as an important research field for multidimensional data and correlation analysis in recent years. Parallel coordinates (PCs) are one of the popular techniques to visual high-dimensional data. A problem with the PCs technique is that it suffers from crowding, a clutter which hides important data and obfuscates the information. Earlier research has been conducted to reduce clutter without loss in data content. We introduce the use of image processing techniques as an approach for assessing the performance of clutter reduction techniques in PC. We use histogram analysis as our first measure, where the mean feature of the color histograms of the possible alternative orderings of coordinates for the PC images is calculated and compared. The second measure is the extracted contrast feature from the texture of PC images based on gray-level co-occurrence matrices. The results show that the best PC image is the one that has the minimal mean value of the color histogram feature and the maximal contrast value of the texture feature. In addition to its simplicity, the proposed assessment method has the advantage of objectively assessing alternative ordering of PC visualization.

  4. Transportation informatics : advanced image processing techniques automated pavement distress evaluation.

    Science.gov (United States)

    2010-01-01

    The current project, funded by MIOH-UTC for the period 1/1/2009- 4/30/2010, is concerned : with the development of the framework for a transportation facility inspection system using : advanced image processing techniques. The focus of this study is ...

  5. A novel image inpainting technique based on median diffusion

    Indian Academy of Sciences (India)

    The concept of digital inpainting was introduced by Bertalmio et al. (2000). The proposed algorithm addresses inpainting of images with a homogeneous or heteroge- neous background. The technique is based on diffusing median value of pixels which are exterior to inpainting area into the area to be inpainted. This is a ...

  6. Comparing Generative Adversarial Network Techniques for Image Creation and Modification

    NARCIS (Netherlands)

    Pieters, Mathijs; Wiering, Marco

    2018-01-01

    Generative adversarial networks (GANs) have demonstrated to be successful at generating realistic real-world images. In this paper we compare various GAN techniques, both supervised and unsupervised. The effects on training stability of different objective functions are compared. We add an encoder

  7. The current role of imaging techniques in faecal incontinence

    NARCIS (Netherlands)

    Terra, M. P.; Stoker, J.

    2006-01-01

    Faecal incontinence is a common multifactorial disorder. Major causes of faecal incontinence are related to vaginal delivery and prior anorectal surgery. In addition to medical history and physical examination, several anorectal functional tests and imaging techniques can be used to assess the

  8. Recent Advances in Techniques for Hyperspectral Image Processing

    Science.gov (United States)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; hide

    2009-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than 30 years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspectral data. In this paper, we provide a seminal view on recent advances in techniques for hyperspectral image processing. Our main focus is on the design of techniques able to deal with the highdimensional nature of the data, and to integrate the spatial and spectral information. Performance of the discussed techniques is evaluated in different analysis scenarios. To satisfy time-critical constraints in specific applications, we also develop efficient parallel implementations of some of the discussed algorithms. Combined, these parts provide an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on future potentials and emerging challenges in the design of robust hyperspectral imaging algorithms

  9. Application of digital-image-correlation techniques in analysing ...

    Indian Academy of Sciences (India)

    experimental results obtained using the digital image correlation analysis is used to demonstrate the crack ... The analysis procedure of the DIC method is shown in figure 1. The analysis region is divided .... The observation also proves the accuracy of the qualitative analyses by using the DIC technique. However, fig-.

  10. Feminist Pedagogy, Body Image, and the Dance Technique Class

    Science.gov (United States)

    Barr, Sherrie; Oliver, Wendy

    2016-01-01

    This paper investigates the evolution of feminist consciousness in dance technique class as related to body image, the myth of the perfect body, and the development of feminist pedagogy. Western concert dance forms have often been taught in a manner where imitating the teacher is primary in the learning process. In this traditional scenario,…

  11. Applying the digital-image-correlation technique to measure the ...

    Indian Academy of Sciences (India)

    4.2 Image analysis. The DIC technique is used to analyse the column deformation. After the position of every mark is traced, two parallel observation lines on the surface of column (as shown in figure 8) are cho- sen. There are 181 equal spaced points on each line. The positions of these points are calculated using B-Spline ...

  12. Coronary imaging techniques with emphasis on CT and MRI

    International Nuclear Information System (INIS)

    Lederlin, Mathieu; Latrabe, Valerie; Corneloup, Olivier; Cochet, Hubert; Montaudon, Michel; Laurent, Francois; Thambo, Jean-Benoit

    2011-01-01

    Coronary artery imaging in children is challenging, with high demands both on temporal and spatial resolution due to high heart rates and smaller anatomy. Although invasive conventional coronary angiography remains the benchmark technique, over the past 10 years, CT and MRI have emerged in the field of coronary imaging. The choice of hardware is important. For CT, the minimum requirement is a 64-channel scanner. The temporal resolution of the scanner is most important for optimising image quality and minimising radiation dose. Manufacturers have developed several modes of electrocardiographic (ECG) triggering to facilitate dose reduction. Recent technical advances have opened new possibilities in MRI coronary imaging. As a non-ionising radiation technique, MRI is of great interest in paediatric imaging. It is currently recommended in centres with appropriate expertise for the screening of patients with suspected congenital coronary anomalies. However, MRI is still not feasible in infants. This review describes and discusses the technical requirements and the pros and cons of all three techniques. (orig.)

  13. Reducing the absorbed dose in analogue radiography of infant chest images by improving the image quality, using image processing techniques

    International Nuclear Information System (INIS)

    Karimian, A.; Yazdani, S.; Askari, M. A.

    2011-01-01

    Radiographic inspection is one of the most widely employed techniques for medical testing methods. Because of poor contrast and high un-sharpness of radiographic image quality in films, converting radiographs to a digital format and using further digital image processing is the best method of enhancing the image quality and assisting the interpreter in their evaluation. In this research work, radiographic films of 70 infant chest images with different sizes of defects were selected. To digitise the chest images and employ image processing the two algorithms (i) spatial domain and (ii) frequency domain techniques were used. The MATLAB environment was selected for processing in the digital format. Our results showed that by using these two techniques, the defects with small dimensions are detectable. Therefore, these suggested techniques may help medical specialists to diagnose the defects in the primary stages and help to prevent more repeat X-ray examination of paediatric patients. (authors)

  14. Template Matching of Colored Image Based on Quaternion Fourier Transform and Image Pyramid Techniques

    Directory of Open Access Journals (Sweden)

    M.I. KHALIL

    2016-04-01

    Full Text Available Template matching method is one of the most significant object recognition techniques and it has many applications in the field of digital signal processing and image processing and it is the base for object tracking in computer vision field. The traditional template matching by correlation is performed between gray template image w and the candidate gray image f where the template’s position is to be determined in the candidate image. This task can be achieved by measuring the similarity between the template image and the candidate image to identify and localize the existence of object instances within an image. When applying this method to colored image, the image must be converted to a gray one or decomposed to its RGB components to be processed separately. The current paper aims to apply the template matching technique to colored images via generating the quaternion Fourier transforms of both the template and candidate colored image and hence performing the cross-correlation between those transforms. Moreover, this approach is improved by representing both the image and template as pyramid multi-resolution format to reduce the time of processing. The proposed algorithm is implemented and applied to different images and templates using Matlab functions.

  15. Adaptive differential correspondence imaging based on sorting technique

    Directory of Open Access Journals (Sweden)

    Heng Wu

    2017-04-01

    Full Text Available We develop an adaptive differential correspondence imaging (CI method using a sorting technique. Different from the conventional CI schemes, the bucket detector signals (BDS are first processed by a differential technique, and then sorted in a descending (or ascending order. Subsequently, according to the front and last several frames of the sorted BDS, the positive and negative subsets (PNS are created by selecting the relative frames from the reference detector signals. Finally, the object image is recovered from the PNS. Besides, an adaptive method based on two-step iteration is designed to select the optimum number of frames. To verify the proposed method, a single-detector computational ghost imaging (GI setup is constructed. We experimentally and numerically compare the performance of the proposed method with different GI algorithms. The results show that our method can improve the reconstruction quality and reduce the computation cost by using fewer measurement data.

  16. Wear Detection of Drill Bit by Image-based Technique

    Science.gov (United States)

    Sukeri, Maziyah; Zulhilmi Paiz Ismadi, Mohd; Rahim Othman, Abdul; Kamaruddin, Shahrul

    2018-03-01

    Image processing for computer vision function plays an essential aspect in the manufacturing industries for the tool condition monitoring. This study proposes a dependable direct measurement method to measure the tool wear using image-based analysis. Segmentation and thresholding technique were used as the means to filter and convert the colour image to binary datasets. Then, the edge detection method was applied to characterize the edge of the drill bit. By using cross-correlation method, the edges of original and worn drill bits were correlated to each other. Cross-correlation graphs were able to detect the difference of the worn edge despite small difference between the graphs. Future development will focus on quantifying the worn profile as well as enhancing the sensitivity of the technique.

  17. Imaging and machine learning techniques for diagnosis of Alzheimer's disease.

    Science.gov (United States)

    Mirzaei, Golrokh; Adeli, Anahita; Adeli, Hojjat

    2016-12-01

    Alzheimer's disease (AD) is a common health problem in elderly people. There has been considerable research toward the diagnosis and early detection of this disease in the past decade. The sensitivity of biomarkers and the accuracy of the detection techniques have been defined to be the key to an accurate diagnosis. This paper presents a state-of-the-art review of the research performed on the diagnosis of AD based on imaging and machine learning techniques. Different segmentation and machine learning techniques used for the diagnosis of AD are reviewed including thresholding, supervised and unsupervised learning, probabilistic techniques, Atlas-based approaches, and fusion of different image modalities. More recent and powerful classification techniques such as the enhanced probabilistic neural network of Ahmadlou and Adeli should be investigated with the goal of improving the diagnosis accuracy. A combination of different image modalities can help improve the diagnosis accuracy rate. Research is needed on the combination of modalities to discover multi-modal biomarkers.

  18. Image reconstruction technique using projection data from neutron tomography system

    Directory of Open Access Journals (Sweden)

    Waleed Abd el Bar

    2015-12-01

    Full Text Available Neutron tomography is a very powerful technique for nondestructive evaluation of heavy industrial components as well as for soft hydrogenous materials enclosed in heavy metals which are usually difficult to image using X-rays. Due to the properties of the image acquisition system, the projection images are distorted by several artifacts, and these reduce the quality of the reconstruction. In order to eliminate these harmful effects the projection images should be corrected before reconstruction. This paper gives a description of a filter back projection (FBP technique, which is used for reconstruction of projected data obtained from transmission measurements by neutron tomography system We demonstrated the use of spatial Discrete Fourier Transform (DFT and the 2D Inverse DFT in the formulation of the method, and outlined the theory of reconstruction of a 2D neutron image from a sequence of 1D projections taken at different angles between 0 and π in MATLAB environment. Projections are generated by applying the Radon transform to the original image at different angles.

  19. Fluorescence imaging techniques for studying Drosophila embryo development.

    Science.gov (United States)

    Mavrakis, Manos; Rikhy, Richa; Lilly, Mary; Lippincott-Schwartz, Jennifer

    2008-06-01

    This unit describes fluorescence-based techniques for noninvasive imaging of development in living Drosophila embryos, discussing considerations for fluorescent imaging within living embryos and providing protocols for generation of flies expressing fluorescently tagged proteins and for preparation of embryos for fluorescent imaging. The unit details time-lapse confocal imaging of live embryos and discusses optimizing image acquisition and performing three-dimensional imaging. Finally, the unit provides a variety of specific methods for optical highlighting of specific subsets of fluorescently tagged proteins and organelles in the embryo, including fluorescence recovery after photobleaching (FRAP), fluorescence loss in photobleaching (FLIP), and photoactivation techniques, permitting analysis of specific movements of fluorescently tagged proteins within cells. These protocols, together with the relative ease of generating transgenic animals and the ability to express tagged proteins in specific tissues or at specific developmental times, provide powerful means for examining in vivo behavior of any tagged protein in embryos in myriad mutant backgrounds. Copyright 2008 by John Wiley & Sons, Inc.

  20. Appropriate electromagnetic techniques for imaging geothermal fracture zones

    Energy Technology Data Exchange (ETDEWEB)

    Groom, R.; Walker, P. [PetRos EiKon Incorporated, Ontario (Canada)

    1996-05-01

    Electromagnetic surface detection of fracture zones has often been approached by using the magnetotelluric method. This technique suffers greatly from the quantity and scale of the conductive inhomogeneities lying above the fracture zones. Additionally, it suffers from the inherent inability to focus the source on the target. There are no such source focusing capabilities in magnetotellurics. Accordingly, the quantity of magnetotelluric data required to resolve targets in such complex conditions can make the technique inefficient and insufficient from a cost perspective. When attempting to reveal a subsurface structure and image it, the basic physical responses at hand must be kept in mind, and the appropriate source must be utilized, which most effectively illuminates the target. A further advantage to controlled sources is that imaging techniques may be used to accentuate the response due to knowledge and control of the source.

  1. A dual-view digital tomosynthesis imaging technique for improved chest imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuncheng; Lai, Chao-Jen; Wang, Tianpeng; Shaw, Chris C., E-mail: cshaw@mdanderson.org [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77054 (United States)

    2015-09-15

    Purpose: Digital tomosynthesis (DTS) has been shown to be useful for reducing the overlapping of abnormalities with anatomical structures at various depth levels along the posterior–anterior (PA) direction in chest radiography. However, DTS provides crude three-dimensional (3D) images that have poor resolution in the lateral view and can only be displayed with reasonable quality in the PA view. Furthermore, the spillover of high-contrast objects from off-fulcrum planes generates artifacts that may impede the diagnostic use of the DTS images. In this paper, the authors describe and demonstrate the use of a dual-view DTS technique to improve the accuracy of the reconstructed volume image data for more accurate rendition of the anatomy and slice images with improved resolution and reduced artifacts, thus allowing the 3D image data to be viewed in views other than the PA view. Methods: With the dual-view DTS technique, limited angle scans are performed and projection images are acquired in two orthogonal views: PA and lateral. The dual-view projection data are used together to reconstruct 3D images using the maximum likelihood expectation maximization iterative algorithm. In this study, projection images were simulated or experimentally acquired over 360° using the scanning geometry for cone beam computed tomography (CBCT). While all projections were used to reconstruct CBCT images, selected projections were extracted and used to reconstruct single- and dual-view DTS images for comparison with the CBCT images. For realistic demonstration and comparison, a digital chest phantom derived from clinical CT images was used for the simulation study. An anthropomorphic chest phantom was imaged for the experimental study. The resultant dual-view DTS images were visually compared with the single-view DTS images and CBCT images for the presence of image artifacts and accuracy of CT numbers and anatomy and quantitatively compared with root-mean-square-deviation (RMSD) values

  2. The molecular imaging approach to image infections and inflammation by nuclear medicine techniques

    NARCIS (Netherlands)

    Signore, Alberto; Glaudemans, Andor W. J. M.

    2011-01-01

    Inflammatory and infectious diseases are a heterogeneous class of diseases that may be divided into infections, acute inflammation and chronic inflammation. Radiological imaging techniques have, with the exception of functional MRI, high sensitivity but lack in specificity. Nuclear medicine

  3. Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

    Science.gov (United States)

    Pollard, Victoria J.; Herron, Andrew J.

    2017-01-01

    Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available.

  4. Meat quality evaluation by hyperspectral imaging technique: an overview.

    Science.gov (United States)

    Elmasry, Gamal; Barbin, Douglas F; Sun, Da-Wen; Allen, Paul

    2012-01-01

    During the last two decades, a number of methods have been developed to objectively measure meat quality attributes. Hyperspectral imaging technique as one of these methods has been regarded as a smart and promising analytical tool for analyses conducted in research and industries. Recently there has been a renewed interest in using hyperspectral imaging in quality evaluation of different food products. The main inducement for developing the hyperspectral imaging system is to integrate both spectroscopy and imaging techniques in one system to make direct identification of different components and their spatial distribution in the tested product. By combining spatial and spectral details together, hyperspectral imaging has proved to be a promising technology for objective meat quality evaluation. The literature presented in this paper clearly reveals that hyperspectral imaging approaches have a huge potential for gaining rapid information about the chemical structure and related physical properties of all types of meat. In addition to its ability for effectively quantifying and characterizing quality attributes of some important visual features of meat such as color, quality grade, marbling, maturity, and texture, it is able to measure multiple chemical constituents simultaneously without monotonous sample preparation. Although this technology has not yet been sufficiently exploited in meat process and quality assessment, its potential is promising. Developing a quality evaluation system based on hyperspectral imaging technology to assess the meat quality parameters and to ensure its authentication would bring economical benefits to the meat industry by increasing consumer confidence in the quality of the meat products. This paper provides a detailed overview of the recently developed approaches and latest research efforts exerted in hyperspectral imaging technology developed for evaluating the quality of different meat products and the possibility of its widespread

  5. The clinical consequences of advanced imaging techniques in Barrett's esophagus.

    Science.gov (United States)

    Boerwinkel, David F; Swager, Anne-Fré; Curvers, Wouter L; Bergman, Jacques J G H M

    2014-03-01

    Evaluation of patients with Barrett's esophagus (BE) using dye-based chromoendoscopy, optical chromoendoscopy, autofluorescence imaging, or confocal laser endomicroscopy does not significantly increase the number of patients with a diagnosis of early neoplasia compared with high-definition white light endoscopy (HD-WLE) with random biopsy analysis. These newer imaging techniques are not more effective in standard surveillance of patients with BE because the prevalence of early neoplasia is low and HD-WLE with random biopsy analysis detects most cases of neoplasia. The evaluation and treatment of patients with BE and early-stage neoplasia should be centralized in tertiary referral centers, where procedures are performed under optimal conditions, by expert endoscopists. Lesions that require resection are almost always detected by HD-WLE, although advanced imaging techniques can detect additional flat lesions. However, these are of limited clinical significance because they are effectively eradicated by ablation therapy. No endoscopic imaging technique can reliably assess submucosal or lymphangio-invasion. Endoscopic resection of early-stage neoplasia in patients with BE is important for staging and management. Optical chromoendoscopy can also be used to evaluate lesions before endoscopic resection and in follow-up after successful ablation therapy. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  6. State-of-the-art imaging techniques in endoscopic ultrasound

    Science.gov (United States)

    Săftoiu, Adrian

    2011-01-01

    Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment, with a major clinical impact in digestive and mediastinal diseases. State-of-the-art EUS equipment now includes real-time sono-elastography, which might be useful for a better characterization of lesions and increased accuracy of differential diagnosis (for e.g. lymph nodes or focal pancreatic lesions). Contrast-enhanced EUS imaging is also available, and is already being used for the differential diagnosis of focal pancreatic masses. The recent development of low mechanical index contrast harmonic EUS imaging offers hope for improved diagnosis, staging and monitoring of anti-angiogenic treatment. Tridimensional EUS (3D-EUS) techniques can be applied to enhance the spatial understanding of EUS anatomy, especially for improved staging of tumors, obtained through a better assessment of the relationship with major surrounding vessels. Despite the progress gained through all these imaging techniques, they cannot replace cytological or histological diagnosis. However, real-time optical histological diagnosis can be achieved through the use of single-fiber confocal laser endomicroscopy techniques placed under real-time EUS-guidance through a 22G needle. Last, but not least, EUS-assisted natural orifice transluminal endoscopic surgery (NOTES) procedures offer a whole new area of imaging applications, used either for combination of NOTES peritoneoscopy and intraperitoneal EUS, but also for access of retroperitoneal organs through posterior EUS guidance. PMID:21390138

  7. Applicability of three-dimensional imaging techniques in fetal medicine

    Energy Technology Data Exchange (ETDEWEB)

    Werner Junior, Heron; Daltro, Pedro; Gasparetto, Emerson Leandro, E-mail: heronwerner@hotmail.com [Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Santos, Jorge Lopes dos; Belmonte, Simone; Ribeiro, Gerson [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Marchiori, Edson [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2016-09-15

    Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. (author)

  8. Comparison of additive image fusion vs. feature-level image fusion techniques for enhanced night driving

    Science.gov (United States)

    Bender, Edward J.; Reese, Colin E.; Van Der Wal, Gooitzen S.

    2003-02-01

    The Night Vision & Electronic Sensors Directorate (NVESD) has conducted a series of image fusion evaluations under the Head-Tracked Vision System (HTVS) program. The HTVS is a driving system for both wheeled and tracked military vehicles, wherein dual-waveband sensors are directed in a more natural head-slewed imaging mode. The HTVS consists of thermal and image-intensified TV sensors, a high-speed gimbal, a head-mounted display, and a head tracker. A series of NVESD field tests over the past two years has investigated the degree to which additive (A+B) image fusion of these sensors enhances overall driving performance. Additive fusion employs a single (but user adjustable) fractional weighting for all the features of each sensor's image. More recently, NVESD and Sarnoff Corporation have begun a cooperative effort to evaluate and refine Sarnoff's "feature-level" multi-resolution (pyramid) algorithms for image fusion. This approach employs digital processing techniques to select at each image point only the sensor with the strongest features, and to utilize only those features to reconstruct the fused video image. This selection process is performed simultaneously at multiple scales of the image, which are combined to form the reconstructed fused image. All image fusion techniques attempt to combine the "best of both sensors" in a single image. Typically, thermal sensors are better for detecting military threats and targets, while image-intensified sensors provide more natural scene cues and detect cultural lighting. This investigation will address the differences between additive fusion and feature-level image fusion techniques for enhancing the driver's overall situational awareness.

  9. Fractal Image Compression Based on High Entropy Values Technique

    Directory of Open Access Journals (Sweden)

    Douaa Younis Abbaas

    2018-04-01

    Full Text Available There are many attempts tried to improve the encoding stage of FIC because it consumed time. These attempts worked by reducing size of the search pool for pair range-domain matching but most of them led to get a bad quality, or a lower compression ratio of reconstructed image. This paper aims to present a method to improve performance of the full search algorithm by combining FIC (lossy compression and another lossless technique (in this case entropy coding is used. The entropy technique will reduce size of the domain pool (i. e., number of domain blocks based on the entropy value of each range block and domain block and then comparing the results of full search algorithm and proposed algorithm based on entropy technique to see each of which give best results (such as reduced the encoding time with acceptable values in both compression quali-ty parameters which are C. R (Compression Ratio and PSNR (Image Quality. The experimental results of the proposed algorithm proven that using the proposed entropy technique reduces the encoding time while keeping compression rates and reconstruction image quality good as soon as possible.

  10. Dual self-image technique for beam collimation

    Science.gov (United States)

    Herrera-Fernandez, Jose Maria; Sanchez-Brea, Luis Miguel; Torcal-Milla, Francisco Jose; Morlanes, Tomas; Bernabeu, Eusebio

    2016-07-01

    We propose an accurate technique for obtaining highly collimated beams, which also allows testing the collimation degree of a beam. It is based on comparing the period of two different self-images produced by a single diffraction grating. In this way, variations in the period of the diffraction grating do not affect to the measuring procedure. Self-images are acquired by two CMOS cameras and their periods are determined by fitting the variogram function of the self-images to a cosine function with polynomial envelopes. This way, loss of accuracy caused by imperfections of the measured self-images is avoided. As usual, collimation is obtained by displacing the collimation element with respect to the source along the optical axis. When the period of both self-images coincides, collimation is achieved. With this method neither a strict control of the period of the diffraction grating nor a transverse displacement, required in other techniques, are necessary. As an example, a LED considering paraxial approximation and point source illumination is collimated resulting a resolution in the divergence of the beam of δ φ =+/- 1.57 μ {rad}.

  11. Assessment of banana fruit maturity by image processing technique.

    Science.gov (United States)

    Surya Prabha, D; Satheesh Kumar, J

    2015-03-01

    Maturity stage of fresh banana fruit is an important factor that affects the fruit quality during ripening and marketability after ripening. The ability to identify maturity of fresh banana fruit will be a great support for farmers to optimize harvesting phase which helps to avoid harvesting either under-matured or over-matured banana. This study attempted to use image processing technique to detect the maturity stage of fresh banana fruit by its color and size value of their images precisely. A total of 120 images comprising 40 images from each stage such as under-mature, mature and over-mature were used for developing algorithm and accuracy prediction. The mean color intensity from histogram; area, perimeter, major axis length and minor axis length from the size values, were extracted from the calibration images. Analysis of variance between each maturity stage on these features indicated that the mean color intensity and area features were more significant in predicting the maturity of banana fruit. Hence, two classifier algorithms namely, mean color intensity algorithm and area algorithm were developed and their accuracy on maturity detection was assessed. The mean color intensity algorithm showed 99.1 % accuracy in classifying the banana fruit maturity. The area algorithm classified the under-mature fruit at 85 % accuracy. Hence the maturity assessment technique proposed in this paper could be used commercially to develop a field based complete automatic detection system to take decision on the right time of harvest by the banana growers.

  12. The Handbook of Medical Image Perception and Techniques

    Science.gov (United States)

    Samei, Ehsan; Krupinski, Elizabeth

    2014-07-01

    Peter Ayton; Part V. Optimization and Practical Issues: 25. Optimization of 2D and 3D radiographic systems Jeff Siewerdson; 26. Applications of AFC methodology in optimization of CT imaging systems Kent Ogden and Walter Huda; 27. Perceptual issues in reading mammograms Margarita Zuley; 28. Perceptual optimization of display processing techniques Richard Van Metter; 29. Optimization of display systems Elizabeth Krupinski and Hans Roehrig; 30. Ergonomic radiologist workplaces in the PACS environment Carl Zylack; Part VI. Epilogue: 31. Future prospects of medical image perception Ehsan Samei and Elizabeth Krupinski; Index.

  13. Positron imaging techniques for process engineering: recent developments at Birmingham

    Science.gov (United States)

    Parker, D. J.; Leadbeater, T. W.; Fan, X.; Hausard, M. N.; Ingram, A.; Yang, Z.

    2008-09-01

    For over 20 years the University of Birmingham has been using positron-emitting radioactive tracers to study engineering processes. The imaging technique of positron emission tomography (PET), widely used for medical applications, has been adapted for these studies, and the complementary technique of positron emission particle tracking (PEPT) has been developed. The radioisotopes are produced using the Birmingham MC40 cyclotron, and a variety of techniques are employed to produce suitable tracers in a wide range of forms. Detectors originally designed for medical use have been modified for engineering applications, allowing measurements to be made on real process equipment, at laboratory or pilot plant scale. This paper briefly reviews the capability of the techniques and introduces a few of the many processes to which they have been applied.

  14. Application of digital image processing techniques to astronomical imagery, 1979

    Science.gov (United States)

    Lorre, J. J.

    1979-01-01

    Several areas of applications of image processing to astronomy were identified and discussed. These areas include: (1) deconvolution for atmospheric seeing compensation; a comparison between maximum entropy and conventional Wiener algorithms; (2) polarization in galaxies from photographic plates; (3) time changes in M87 and methods of displaying these changes; (4) comparing emission line images in planetary nebulae; and (5) log intensity, hue saturation intensity, and principal component color enhancements of M82. Examples are presented of these techniques applied to a variety of objects.

  15. Mesh adaptation technique for Fourier-domain fluorescence lifetime imaging

    International Nuclear Information System (INIS)

    Soloviev, Vadim Y.

    2006-01-01

    A novel adaptive mesh technique in the Fourier domain is introduced for problems in fluorescence lifetime imaging. A dynamical adaptation of the three-dimensional scheme based on the finite volume formulation reduces computational time and balances the ill-posed nature of the inverse problem. Light propagation in the medium is modeled by the telegraph equation, while the lifetime reconstruction algorithm is derived from the Fredholm integral equation of the first kind. Stability and computational efficiency of the method are demonstrated by image reconstruction of two spherical fluorescent objects embedded in a tissue phantom

  16. Statistical techniques for noise removal from visual images

    Science.gov (United States)

    Allred, Lloyd G.; Kelly, Gary E.

    1992-07-01

    The median operator has been demonstrated to be a very effective method for restoring recognizable images from very noisy image data. The power of the median operator stems from its non-algebraic formulation, which prevents erroneous data corrupting the final color computation. A principal drawback is that the median operator replaces all data, erroneous or not, the result being a net loss of information. This paper presents alternative statistical outlier techniques by which erroneous data is readily recognized, but valid data usually remains unchanged. The result is an effective noise removal algorithm with reduced loss of information.

  17. Reduction and analysis techniques for infrared imaging data

    Science.gov (United States)

    Mccaughrean, Mark

    1989-01-01

    Infrared detector arrays are becoming increasingly available to the astronomy community, with a number of array cameras already in use at national observatories, and others under development at many institutions. As the detector technology and imaging instruments grow more sophisticated, more attention is focussed on the business of turning raw data into scientifically significant information. Turning pictures into papers, or equivalently, astronomy into astrophysics, both accurately and efficiently, is discussed. Also discussed are some of the factors that can be considered at each of three major stages; acquisition, reduction, and analysis, concentrating in particular on several of the questions most relevant to the techniques currently applied to near infrared imaging.

  18. [Results and indications of imaging techniques in musculoskeletal diseases].

    Science.gov (United States)

    Ben Hamouda, Mohamed; Bergaoui, Naceur; Douik, Mongi; Ladeb, Fethi

    2002-08-01

    Imaging is necessary in the diagnosis of musculoskeletal diseases and X rays is the first step of this morphological exploration. Ultrasonography is cost effectiveness, without radiation and have to constitute the second step of the exploration of the smooth tissue (tendon, muscle, sheath, synovium and superficial ligaments). Computed tomography with its new technological progress is very effective in the study of the cortical bone. Magnetic resonance imaging, a non irradiating but costly technique, becomes inevitable in several osteo-articular affections. It often makes the examination of last intention to compensate for the inadequacy of ultrasonography and computed tomography.

  19. Adapting content-based image retrieval techniques for the semantic annotation of medical images.

    Science.gov (United States)

    Kumar, Ashnil; Dyer, Shane; Kim, Jinman; Li, Changyang; Leong, Philip H W; Fulham, Michael; Feng, Dagan

    2016-04-01

    The automatic annotation of medical images is a prerequisite for building comprehensive semantic archives that can be used to enhance evidence-based diagnosis, physician education, and biomedical research. Annotation also has important applications in the automatic generation of structured radiology reports. Much of the prior research work has focused on annotating images with properties such as the modality of the image, or the biological system or body region being imaged. However, many challenges remain for the annotation of high-level semantic content in medical images (e.g., presence of calcification, vessel obstruction, etc.) due to the difficulty in discovering relationships and associations between low-level image features and high-level semantic concepts. This difficulty is further compounded by the lack of labelled training data. In this paper, we present a method for the automatic semantic annotation of medical images that leverages techniques from content-based image retrieval (CBIR). CBIR is a well-established image search technology that uses quantifiable low-level image features to represent the high-level semantic content depicted in those images. Our method extends CBIR techniques to identify or retrieve a collection of labelled images that have similar low-level features and then uses this collection to determine the best high-level semantic annotations. We demonstrate our annotation method using retrieval via weighted nearest-neighbour retrieval and multi-class classification to show that our approach is viable regardless of the underlying retrieval strategy. We experimentally compared our method with several well-established baseline techniques (classification and regression) and showed that our method achieved the highest accuracy in the annotation of liver computed tomography (CT) images. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Monitoring of civil engineering structures using Digital Image Correlation technique

    Directory of Open Access Journals (Sweden)

    Świercz A.

    2010-06-01

    Full Text Available The Digital Image Correlation (DIC technique enables full field, noncontact measurements of displacements and strains of a wide variety of objects. An adaptation of the DIC technique for monitoring of civil-engineering structures is presented in the paper. A general concept of the complex, automatic monitoring system, in which the DIC sensor plays an important role is described. Some new software features, which aim to facilitate outdoor measurements and speed up the correlation analysis, is also introduced. As an example of application, measurements of a railway bridge in Nieporet (Poland are presented. The experimental results are compared with displacements of a FEM model of the bridge.

  1. MR imaging of the colon: 'Technique, indications, results and limitations'

    International Nuclear Information System (INIS)

    Ajaj, Waleed; Goyen, Mathias

    2007-01-01

    In the last few years virtual colonography using MR imaging has shown a proceeding development regarding detection and quantification of colorectal pathologies. Dark-lumen MR colonography (MRC) has been a leading tool for the diagnosis of the entire colon and their pathologies. This review article describes some of the underlying techniques of MRC concerning data acquisition, the need for intravenously applied paramagnetic contrast agent, as well as indications, results and limitations of MRC for the detection of colorectal pathologies. In addition, new techniques to improve patient acceptance are discussed

  2. A secure cyclic steganographic technique for color images using randomization

    International Nuclear Information System (INIS)

    Muhammad, K.; Ahmad, J.; Rehman, N.U.

    2014-01-01

    Information Security is a major concern in today's modern era. Almost all the communicating bodies want the security, confidentiality and integrity of their personal data. But this security goal cannot be achieved easily when we are using an open network like internet. Steganography provides one of the best solutions to this problem. This paper represents a new Cyclic Steganographic Technique (CST) based on Least Significant Bit (LSB) for true color (RGB) images. The proposed method hides the secret data in the LSBs of cover image pixels in a randomized cyclic manner. The proposed technique is evaluated using both subjective and objective analysis using histograms changeability, Peak Signal-to-Noise Ratio (PSNR) and Mean Square Error (MSE). Experimentally it is found that the proposed method gives promising results in terms of security, imperceptibility and robustness as compared to some existent methods and vindicates this new algorithm. (author)

  3. Fuzzy logic techniques for blotch feature evaluation in dermoscopy images.

    Science.gov (United States)

    Khan, Azmath; Gupta, Kapil; Stanley, R J; Stoecker, William V; Moss, Randy H; Argenziano, Giuseppe; Soyer, H Peter; Rabinovitz, Harold S; Cognetta, Armand B

    2009-01-01

    Blotches, also called structureless areas, are critical in differentiating malignant melanoma from benign lesions in dermoscopy skin lesion images. In this paper, fuzzy logic techniques are investigated for the automatic detection of blotch features for malignant melanoma discrimination. Four fuzzy sets representative of blotch size and relative and absolute blotch colors are used to extract blotchy areas from a set of dermoscopy skin lesion images. Five previously reported blotch features are computed from the extracted blotches as well as four new features. Using a neural network classifier, malignant melanoma discrimination results are optimized over the range of possible alpha-cuts and compared with results using crisp blotch features. Features computed from blotches using the fuzzy logic techniques based on three plane relative color and blotch size yield the highest diagnostic accuracy of 81.2%.

  4. Image Techniques for Identifying Sea-Ice Parameters

    Directory of Open Access Journals (Sweden)

    Qin Zhang

    2014-10-01

    Full Text Available The estimation of ice forces are critical to Dynamic Positioning (DP operations in Arctic waters. Ice conditions are important for the analysis of ice-structure interaction in an ice field. To monitor sea-ice conditions, cameras are used as field observation sensors on mobile sensor platforms in Arctic. Various image processing techniques, such as Otsu thresholding, k-means clustering, distance transform, Gradient Vector Flow (GVF Snake, mathematical morphology, are then applied to obtain ice concentration, ice types, and floe size distribution from sea-ice images to ensure safe operations of structures in ice covered regions. Those techniques yield acceptable results, and their effectiveness are demonstrated in case studies.

  5. A Review On Segmentation Based Image Compression Techniques

    Directory of Open Access Journals (Sweden)

    S.Thayammal

    2013-11-01

    Full Text Available Abstract -The storage and transmission of imagery become more challenging task in the current scenario of multimedia applications. Hence, an efficient compression scheme is highly essential for imagery, which reduces the requirement of storage medium and transmission bandwidth. Not only improvement in performance and also the compression techniques must converge quickly in order to apply them for real time applications. There are various algorithms have been done in image compression, but everyone has its own pros and cons. Here, an extensive analysis between existing methods is performed. Also, the use of existing works is highlighted, for developing the novel techniques which face the challenging task of image storage and transmission in multimedia applications.

  6. Study on Efficiency of Fusion Techniques for IKONOS Images

    International Nuclear Information System (INIS)

    Liu, Yanmei; Yu, Haiyang; Guijun, Yang; Nie, Chenwei; Yang, Xiaodong; Ren, Dong

    2014-01-01

    Many image fusion techniques have been proposed to achieve optimal resolution in the spatial and spectral domains. Six different merging methods were listed in this paper and the efficiency of fusion techniques was assessed in qualitative and quantitative aspect. Both local and global evaluation parameters were used in the spectral quality and a Laplace filter method was used in spatial quality assessment. By simulation, the spectral quality of the images merged by Brovery was demonstrated to be the worst. In contrast, GS and PCA algorithms, especially the Pansharpening provided higher spectral quality than the standard Brovery, wavelet and CN methods. In spatial quality assessment, the CN method represented best compared with that of others, while the Brovery algorithm was worst. The wavelet parameters that performed best achieved acceptable spectral and spatial quality compared to the others

  7. A New Class of Phantom Materials for Poroelastography Imaging Techniques.

    Science.gov (United States)

    Chaudhry, Anuj; Yazdi, Iman K; Kongari, Rohit; Tasciotti, Ennio; Righetti, Raffaella

    2016-05-01

    Poroelastography is an elastographic technique used to image the temporal mechanical behavior of tissues. One of the major challenges in determining experimental potentials and limitations of this technique has been the lack of complex and realistic controlled phantoms that could be used to corroborate the limited number of theoretical and simulation studies available in the literature as well as to predict its performance in complex experimental situations and in a variety of conditions. In the study described here, we propose and analyze a new class of phantom materials for temporal elastography imaging. The results indicate that, by using polyacrylamide, we can generate inhomogeneous elastographic phantoms with controlled fluid content and fluid flow properties, while maintaining mechanical and ultrasonic properties similar to those of soft tissues. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  8. A maximum entropy reconstruction technique for tomographic particle image velocimetry

    International Nuclear Information System (INIS)

    Bilsky, A V; Lozhkin, V A; Markovich, D M; Tokarev, M P

    2013-01-01

    This paper studies a novel approach for reducing tomographic PIV computational complexity. The proposed approach is an algebraic reconstruction technique, termed MENT (maximum entropy). This technique computes the three-dimensional light intensity distribution several times faster than SMART, using at least ten times less memory. Additionally, the reconstruction quality remains nearly the same as with SMART. This paper presents the theoretical computation performance comparison for MENT, SMART and MART, followed by validation using synthetic particle images. Both the theoretical assessment and validation of synthetic images demonstrate significant computational time reduction. The data processing accuracy of MENT was compared to that of SMART in a slot jet experiment. A comparison of the average velocity profiles shows a high level of agreement between the results obtained with MENT and those obtained with SMART. (paper)

  9. A new approach to electrical impedance imaging technique

    International Nuclear Information System (INIS)

    Afroj Quadir, K.; Nasir, F.; Rahman, M.; Rabbani, K.S.

    2004-09-01

    It is possible to obtain a 2 dimensional (2D) image of a volume conductor, to locate a few widely separated objects, by driving ac constant currents through two orthogonal pairs of electrodes and measuring the resulting potential differences between several diagonally placed electrodes at the centre and back-projecting their impedance values along equi-potential lines. This has been termed as Pigeon Hole Imaging (PHI). Experimental verification has been attempted using a small insulating object placed at different locations in a saline filled 2D phantom. For a 6 x 6 matrix, the image in 16 pixels in close proximity of the diagonal along which electrodes are arranged, coincide with the object positions, while they do nt for the remaining 20 pixels. We applied a new technique where image smearing patterns have been used to correct the images in 14 of these pixels while 6 pixels near the two opposite comers still remain uncertain. Thus 30 pixels out of 36 give the right object position which may be termed a success. The concept may be extended further to higher order matrices by increasing the number of diagonal electrodes. The present work mainly concentrates on the feasibility of localization of a single small object in one matrix position of the image. (author)

  10. A patient image-based technique to assess the image quality of clinical chest radiographs

    Science.gov (United States)

    Lin, Yuan; Samei, Ehsan; Luo, Hui; Dobbins, James T., III; McAdams, H. Page; Wang, Xiaohui; Sehnert, William J.; Barski, Lori; Foos, David H.

    2011-03-01

    Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system DQE and MTF, the exposure technique, and the particular image processing method and processing parameters. However, when assessing a clinical image, radiologists seldom refer to these factors, but rather examine several specific regions of the image to see whether the image is suitable for diagnosis. In this work, we developed a new strategy to learn and simulate radiologists' evaluation process on actual clinical chest images. Based on this strategy, a preliminary study was conducted on 254 digital chest radiographs (38 AP without grids, 35 AP with 6:1 ratio grids and 151 PA with 10:1 ratio grids). First, ten regional based perceptual qualities were summarized through an observer study. Each quality was characterized in terms of a physical quantity measured from the image, and as a first step, the three physical quantities in lung region were then implemented algorithmically. A pilot observer study was performed to verify the correlation between image perceptual qualities and physical quantitative qualities. The results demonstrated that our regional based metrics have promising performance for grading perceptual properties of chest radiographs.

  11. Enhanced EDX images by fusion of multimodal SEM images using pansharpening techniques.

    Science.gov (United States)

    Franchi, G; Angulo, J; Moreaud, M; Sorbier, L

    2018-01-01

    The goal of this paper is to explore the potential interest of image fusion in the context of multimodal scanning electron microscope (SEM) imaging. In particular, we aim at merging the backscattered electron images that usually have a high spatial resolution but do not provide enough discriminative information to physically classify the nature of the sample, with energy-dispersive X-ray spectroscopy (EDX) images that have discriminative information but a lower spatial resolution. The produced images are named enhanced EDX. To achieve this goal, we have compared the results obtained with classical pansharpening techniques for image fusion with an original approach tailored for multimodal SEM fusion of information. Quantitative assessment is obtained by means of two SEM images and a simulated dataset produced by a software based on PENELOPE. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  12. Early Pest Identification in Greenhouse Crops using Image Processing Techniques

    OpenAIRE

    Mr. S. R. Pokharkar; Dr. Mrs. V. R. Thool

    2012-01-01

    Early disease detection is a major challenge in agriculture field.Hence proper measures has to be taken to fight bioagressors ofcrops while minimizing the use of pesticides. The techniques ofmachine vision are extensively applied to agricultural science,and it has great perspective especially in the plant protectionfield,which ultimately leads to crops management. Our goal isearly detection of bioagressors. The paper describes a softwareprototype system for pest detection on the infected imag...

  13. Investigation progress of imaging techniques monitoring stem cell therapy

    International Nuclear Information System (INIS)

    Wu Jun; An Rui

    2006-01-01

    Recently stem cell therapy has showed potential clinical application in diabetes mellitus, cardiovascular diseases, malignant tumor and trauma. Efficient techniques of non-invasively monitoring stem cell transplants will accelerate the development of stem cell therapies. This paper briefly reviews the clinical practice of stem cell, in addition, makes a review of monitoring methods including magnetic resonance and radionuclide imaging which have been used in stem cell therapy. (authors)

  14. Extracted image analysis: a technique for deciphering mediated portrayals.

    Science.gov (United States)

    Berg, D H; Coutts, L B

    1995-01-01

    A technique for analyzing print media that we have developed as a consequence of our interest in the portrayal of women in menstrual product advertising is reported. The technique, which we call extracted image analysis, involves a unique application of grounded theory and the concomitant heuristic use of the concept of ideal type (Weber, 1958). It provides a means of heuristically conceptualizing the answer to a variant of the "What is going on here?" question asked in analysis of print communication, that is, "Who is being portrayed/addressed here?" Extracted image analysis involves the use of grounded theory to develop ideal typologies. Because the technique re-constructs the ideal types embedded in a communication, it possesses considerable potential as a means of identifying the profiles of members of identifiable groups held by the producers of the directed messages. In addition, the analysis of such portrayals over time would be particularly well suited to extracted image analysis. A number of other possible applications are also suggested.

  15. Radioactive seed localizations from computed tomography imaging technique

    International Nuclear Information System (INIS)

    Ayyangar, K.M.; Dobelbower, R.R.; Saw, C.B.; Korb, L.J.

    1994-01-01

    A method that combines radiographic localization of seeds in brachytherapy implant with computed tomography (CT) images has been developed to provide accurate seed location and dose distribution data, in relation to the three dimensional localization of target volume and critical organs at risk. The accurate determination of radioactive seed locations in permanent implants from CT scans is limited by the magnitude of the pixel size and the slice thickness. The image of a single seed may appear in more than one consecutive CT image. A method of removing this artifact using a tolerance diameter about a seed center determined in the previous CT slice is described. To improve further the accuracy of defining the seed positions and orientations, the reconstructed seed coordinates derived from the three film technique were transformed into CT coordinates for dose distribution computations. The differences between this technique and the technique of using CT scans to reconstruct seed coordinates directly were assessed. This method has been applied in the case of prostate implants. It allows for the generation of dose volume histograms for the prostate, bladder and the rectum. (author). 9 refs., 8 figs

  16. Speckle noise reduction in ultrasound images using a discrete wavelet transform-based image fusion technique.

    Science.gov (United States)

    Choi, Hyun Ho; Lee, Ju Hwan; Kim, Sung Min; Park, Sung Yun

    2015-01-01

    Here, the speckle noise in ultrasonic images is removed using an image fusion-based denoising method. To optimize the denoising performance, each discrete wavelet transform (DWT) and filtering technique was analyzed and compared. In addition, the performances were compared in order to derive the optimal input conditions. To evaluate the speckle noise removal performance, an image fusion algorithm was applied to the ultrasound images, and comparatively analyzed with the original image without the algorithm. As a result, applying DWT and filtering techniques caused information loss and noise characteristics, and did not represent the most significant noise reduction performance. Conversely, an image fusion method applying SRAD-original conditions preserved the key information in the original image, and the speckle noise was removed. Based on such characteristics, the input conditions of SRAD-original had the best denoising performance with the ultrasound images. From this study, the best denoising technique proposed based on the results was confirmed to have a high potential for clinical application.

  17. Comparative study of low-energy neutral atom imaging techniques

    International Nuclear Information System (INIS)

    Funsten, H.O.; McComas, D.J.; Scime, E.E.

    1994-01-01

    Low-energy neutral atom (LENA) imaging promise to be a revolutionary tool for global imaging of space plasmas. The technical challenges of LENA detection include separating them from the intense ambient UV without losing information about their incident trajectories, quantifying their trajectories, and obtaining high-sensitivity measurements. Two techniques that have been proposed for this purpose are based on fundamentally different atomic interaction mechanisms between LENAs and a solid; LENA transmission through an ultra thin foil and LENA reflection from a solid surface. Both of these methods provide LENA ionization (for subsequent removal from the UV by electrostatic deflection) and secondary electron emission (for time-of-flight start pulse generation and/or coincidence). They present a comparative study of the transmission and reflection techniques based on differences in atomic interactions with solids and surfaces. Transmission methods are shown to be superior for secondary electron emission rather than reflection methods. Furthermore, transmission methods are shown to be a sufficient for LENA imaging at LENA energies of approximately 1 keV to greater than 30 keV. A hybrid instrument using reflection from a low work function surface for LENA ionization and transmission for secondary electron emission is optimal for imaging of LENAs with energies less than approximately 1 keV

  18. Peering through the flames: imaging techniques for reacting aluminum powders.

    Science.gov (United States)

    Zepper, Ethan T; Pantoya, Michelle L; Bhattacharya, Sukalyan; Marston, Jeremy O; Neuber, Andreas A; Heaps, Ronald J

    2017-03-20

    Combusting metals burn at high temperatures and emit high-intensity radiation in the visible spectrum, which can oversaturate regular imaging sensors and obscure the field of view. Filtering the luminescence can result in limited information and hinder thorough combustion characterization. A method for "seeing through the flames" of a highly luminescent aluminum powder reaction is presented using copper vapor laser (CVL) illumination, synchronized with a high-speed camera. A statistical comparison of combusting aluminum particle agglomerates imaged using various filtration techniques shows the effectiveness of the high-speed camera with a CVL diagnostic approach. When ignited by an electrically induced plasma, aluminum particles are entrained as solid agglomerates that rotate about their centers of mass and are surrounded by emitted, burning gases. The average agglomerate diameter appears to be 160 μm when viewed with standard illumination and a high-speed camera. However, a significantly reduced diameter of 50 μm is recorded when imaged with CVL illumination coupled with a high-speed camera and a 511 nm notch filter. These results indicate alternative imaging techniques are required to resolve the complexities of metal particle combustion.

  19. Characterization of European sword blades through neutron imaging techniques

    Science.gov (United States)

    Salvemini, F.; Grazzi, F.; Peetermans, S.; Gener, M.; Lehmann, E. H.; Zoppi, M.

    2014-09-01

    In the present work, we have studied two European rapier blades, dating back to the period ranging from the Late Renaissance to the Early Modern Age (about 17th to 18th century). In order to determine variation in quality and differences in technology, a study was undertaken with the purpose to observe variations in the blade microstructure (and consequently in the construction processes). The samples, which in the present case were expendable, have been investigated, preliminarily, through standard metallography and then by means of white beam and energy-selective neutron imaging. The comparison of the results, using the two techniques, turned out to be satisfactory, with a substantial quantitative agreement of the results obtained with the two techniques, and show the complementarity of the two methods. Metallography has been considered up to now the method of choice for metal material characterization. The correspondence between the two methods, as well as the non-invasive character of the neutron-based techniques and its possibility to obtain 3D reconstruction, candidate neutron imaging as an important and quantitatively reliable technique for metal characterization.

  20. Techniques to Improve Ultrasound-Switchable Fluorescence Imaging

    Science.gov (United States)

    Kandukuri, Jayanth

    Novel approaches to the improvement of ultrasound-switchable fluorescence (USF) imaging--a relatively new imaging modality that combines ultrasound and optical imaging techniques--have been proposed for early cancer detection. In USF, a high-intensity focused ultrasound (HIFU) beam is used to induce temperature rise within its acoustic focal region due to which a thermo-sensitive USF contrast agent undergoes a switch in its state by increasing the output of fluorescence photons. By using an increase in fluorescence, one can isolate and quantify the fluorescence properties within the ultrasonic focal area. Therefore, USF is able to provide fluorescence contrast while maintaining ultrasound resolution in tissue. The major challenge of the conventional USF technique is its low axial resolution and its sensitivity (i.e. its signal-to-noise ratio (SNR)). This work focuses on investigating and developing a novel USF system design that can improve the resolution and SNR of USF imaging for biological applications. This work can be divided into two major parts: characterizing the performance of a high-intensity focused ultrasound transducer; and improving the axial resolution and sensitivity of the USF technique. Preliminary investigation was conducted by using an IR camera setup to detect temperature variation and thereby study the performance of the high-intensity focused ultrasound transducer to quantify different parameters of ultrasound-induced temperature focal size (UTFS). Investigations are conducted for the purpose of high-resolution imaging with an emphasis on HIFU-induced thermal focus size, short duration of HIFU-induced temperature increase (to avoid thermal diffusion or conduction), and control of HIFU-induced temperature increase within a few degrees Celsius. Next, the focus was shifted to improving the sensitivity of the ultrasound-switchable fluorescence-imaging technique. In this study, the USF signal is encoded with the modulation frequency of the

  1. A computer code to simulate X-ray imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Duvauchelle, Philippe E-mail: philippe.duvauchelle@insa-lyon.fr; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

    2000-09-01

    A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests.

  2. A computer code to simulate X-ray imaging techniques

    International Nuclear Information System (INIS)

    Duvauchelle, Philippe; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

    2000-01-01

    A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests

  3. A Vector Network Analyzer Based on Pulse Generators

    Directory of Open Access Journals (Sweden)

    B. Schulte

    2005-01-01

    Full Text Available A fast four channel network analyzer is introduced to measure S-parameters in a frequency range from 10MHz to 3GHz. The signal generation for this kind of analyzer is based on pulse generators, which are realized with bipolar transistors. The output signal of the transistor is differentiated and two short pulses, a slow and a fast one, with opposite polarities are generated. The slow pulse is suppressed with a clipping network. Thus the generation of very short electrical pulses with a duration of about 100ps is possible. The structure of the following network analyzer is similar to the structure of a conventional four channel network analyzer. All four pulses, which contain the high frequency information of the device under test, are evaluated after the digitalization of intermediate frequencies. These intermediate frequencies are generated with sampling mixers. The recorded data is evaluated with a special analysis technique, which is based on a Fourier transformation. The calibration techniques used are the same as for conventional four channel network analyzers, no new calibration techniques need to be developed.

  4. Kalman filter techniques for accelerated Cartesian dynamic cardiac imaging.

    Science.gov (United States)

    Feng, Xue; Salerno, Michael; Kramer, Christopher M; Meyer, Craig H

    2013-05-01

    In dynamic MRI, spatial and temporal parallel imaging can be exploited to reduce scan time. Real-time reconstruction enables immediate visualization during the scan. Commonly used view-sharing techniques suffer from limited temporal resolution, and many of the more advanced reconstruction methods are either retrospective, time-consuming, or both. A Kalman filter model capable of real-time reconstruction can be used to increase the spatial and temporal resolution in dynamic MRI reconstruction. The original study describing the use of the Kalman filter in dynamic MRI was limited to non-Cartesian trajectories because of a limitation intrinsic to the dynamic model used in that study. Here the limitation is overcome, and the model is applied to the more commonly used Cartesian trajectory with fast reconstruction. Furthermore, a combination of the Kalman filter model with Cartesian parallel imaging is presented to further increase the spatial and temporal resolution and signal-to-noise ratio. Simulations and experiments were conducted to demonstrate that the Kalman filter model can increase the temporal resolution of the image series compared with view-sharing techniques and decrease the spatial aliasing compared with TGRAPPA. The method requires relatively little computation, and thus is suitable for real-time reconstruction. Copyright © 2012 Wiley Periodicals, Inc.

  5. Nonlinear plasmonic imaging techniques and their biological applications

    Science.gov (United States)

    Deka, Gitanjal; Sun, Chi-Kuang; Fujita, Katsumasa; Chu, Shi-Wei

    2017-01-01

    Nonlinear optics, when combined with microscopy, is known to provide advantages including novel contrast, deep tissue observation, and minimal invasiveness. In addition, special nonlinearities, such as switch on/off and saturation, can enhance the spatial resolution below the diffraction limit, revolutionizing the field of optical microscopy. These nonlinear imaging techniques are extremely useful for biological studies on various scales from molecules to cells to tissues. Nevertheless, in most cases, nonlinear optical interaction requires strong illumination, typically at least gigawatts per square centimeter intensity. Such strong illumination can cause significant phototoxicity or even photodamage to fragile biological samples. Therefore, it is highly desirable to find mechanisms that allow the reduction of illumination intensity. Surface plasmon, which is the collective oscillation of electrons in metal under light excitation, is capable of significantly enhancing the local field around the metal nanostructures and thus boosting up the efficiency of nonlinear optical interactions of the surrounding materials or of the metal itself. In this mini-review, we discuss the recent progress of plasmonics in nonlinear optical microscopy with a special focus on biological applications. The advancement of nonlinear imaging modalities (including incoherent/coherent Raman scattering, two/three-photon luminescence, and second/third harmonic generations that have been amalgamated with plasmonics), as well as the novel subdiffraction limit imaging techniques based on nonlinear behaviors of plasmonic scattering, is addressed.

  6. Nonlinear plasmonic imaging techniques and their biological applications

    Directory of Open Access Journals (Sweden)

    Deka Gitanjal

    2016-07-01

    Full Text Available Nonlinear optics, when combined with microscopy, is known to provide advantages including novel contrast, deep tissue observation, and minimal invasiveness. In addition, special nonlinearities, such as switch on/off and saturation, can enhance the spatial resolution below the diffraction limit, revolutionizing the field of optical microscopy. These nonlinear imaging techniques are extremely useful for biological studies on various scales from molecules to cells to tissues. Nevertheless, in most cases, nonlinear optical interaction requires strong illumination, typically at least gigawatts per square centimeter intensity. Such strong illumination can cause significant phototoxicity or even photodamage to fragile biological samples. Therefore, it is highly desirable to find mechanisms that allow the reduction of illumination intensity. Surface plasmon, which is the collective oscillation of electrons in metal under light excitation, is capable of significantly enhancing the local field around the metal nanostructures and thus boosting up the efficiency of nonlinear optical interactions of the surrounding materials or of the metal itself. In this mini-review, we discuss the recent progress of plasmonics in nonlinear optical microscopy with a special focus on biological applications. The advancement of nonlinear imaging modalities (including incoherent/coherent Raman scattering, two/three-photon luminescence, and second/third harmonic generations that have been amalgamated with plasmonics, as well as the novel subdiffraction limit imaging techniques based on nonlinear behaviors of plasmonic scattering, is addressed.

  7. Signal and image processing techniques for functional near-infrared imaging of the human brain

    Science.gov (United States)

    Toronov, Vladislav Y.; Zhang, Xiaofeng; Fabiani, Monica; Gratton, Gabriele; Webb, Andrew G.

    2011-01-01

    Near-infrared spectro-imaging (NIRSI) is a quickly developing method for the in-vivo imaging of biological tissues. In particular, it is now extensively employed for imaging the human brain. In this non-invasive technique, the information about the brain is obtained from the analysis of spatial light bundles formed by the photons traveling from light sources to detectors placed on the surface of the head. Most significant problems in the functional brain NIRSI are the separation of the brain information from the physiological noise in non-cerebral tissues, and the localization of functional signals. In this paper we describe signal and image processing techniques we developed in order to measure two types of functional cerebral signals: the hemodynamic responses, and neuronal responses. PMID:21738383

  8. Image Analysis Technique for Material Behavior Evaluation in Civil Structures

    Science.gov (United States)

    Moretti, Michele; Rossi, Gianluca

    2017-01-01

    The article presents a hybrid monitoring technique for the measurement of the deformation field. The goal is to obtain information about crack propagation in existing structures, for the purpose of monitoring their state of health. The measurement technique is based on the capture and analysis of a digital image set. Special markers were used on the surface of the structures that can be removed without damaging existing structures as the historical masonry. The digital image analysis was done using software specifically designed in Matlab to follow the tracking of the markers and determine the evolution of the deformation state. The method can be used in any type of structure but is particularly suitable when it is necessary not to damage the surface of structures. A series of experiments carried out on masonry walls of the Oliverian Museum (Pesaro, Italy) and Palazzo Silvi (Perugia, Italy) have allowed the validation of the procedure elaborated by comparing the results with those derived from traditional measuring techniques. PMID:28773129

  9. Automated Coronal Loop Identification Using Digital Image Processing Techniques

    Science.gov (United States)

    Lee, Jong K.; Gary, G. Allen; Newman, Timothy S.

    2003-01-01

    The results of a master thesis project on a study of computer algorithms for automatic identification of optical-thin, 3-dimensional solar coronal loop centers from extreme ultraviolet and X-ray 2-dimensional images will be presented. These center splines are proxies of associated magnetic field lines. The project is pattern recognition problems in which there are no unique shapes or edges and in which photon and detector noise heavily influence the images. The study explores extraction techniques using: (1) linear feature recognition of local patterns (related to the inertia-tensor concept), (2) parametric space via the Hough transform, and (3) topological adaptive contours (snakes) that constrains curvature and continuity as possible candidates for digital loop detection schemes. We have developed synthesized images for the coronal loops to test the various loop identification algorithms. Since the topology of these solar features is dominated by the magnetic field structure, a first-order magnetic field approximation using multiple dipoles provides a priori information in the identification process. Results from both synthesized and solar images will be presented.

  10. The role of functional imaging techniques in the dementia

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Young Hoon [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2004-06-01

    Evaluation of dementia in patients with early symptoms of cognitive decline is clinically challenging, but the need for early, accurate diagnosis has become more crucial, since several medication for the treatment of mild to moderate Alzheimer' disease are available. Many neurodegenerative diseases produce significant brain function alteration even when structural imaging (CT of MRI) reveal no specific abnormalities. The role of PET and SPECT brain imaging in the initial assessment and differential diagnosis of dementia is beginning to evolve rapidly and growing evidence indicates that appropriate incorporation of PET into the clinical work up can improve diagnostic and prognostic accuracy with respect to Alzheimer's disease, the most common cause of dementia in the geriatric population. In the fast few years, studies comparing neuropathologic examination with PET have established reliable and consistent accuracy for diagnostic evaluations using PET - accuracies substantially exceeding those of comparable studies of diagnostic value of SPECT or of both modalities assessed side by side, or of clinical evaluations done without nuclear imaging. This review deals the role of functional brian imaging techniques in the evaluation of dementias and the role of nuclear neuroimaging in the early detection and diagnosis of Alzheimer's disease.

  11. Monitoring Therapeutic Treatments against Burkholderia Infections Using Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Tiffany M. Mott

    2013-05-01

    Full Text Available Burkholderia mallei, the etiologic agent of glanders, are Category B select agents with biothreat potential, and yet effective therapeutic treatments are lacking. In this study, we showed that CpG administration increased survival, demonstrating protection in the murine glanders model. Bacterial recovery from infected lungs, liver and spleen was significantly reduced in CpG-treated animals as compared with non-treated mice. Reciprocally, lungs of CpG-treated infected animals were infiltrated with higher levels of neutrophils and inflammatory monocytes, as compared to control animals. Employing the B. mallei bioluminescent strain CSM001 and the Neutrophil-Specific Fluorescent Imaging Agent, bacterial dissemination and neutrophil trafficking were monitored in real-time using multimodal in vivo whole body imaging techniques. CpG-treatment increased recruitment of neutrophils to the lungs and reduced bioluminescent bacteria, correlating with decreased bacterial burden and increased protection against acute murine glanders. Our results indicate that protection of CpG-treated animals was associated with recruitment of neutrophils prior to infection and demonstrated, for the first time, simultaneous real time in vivo imaging of neutrophils and bacteria. This study provides experimental evidence supporting the importance of incorporating optimized in vivo imaging methods to monitor disease progression and to evaluate the efficacy of therapeutic treatment during bacterial infections.

  12. Inside Out: Modern Imaging Techniques to Reveal Animal Anatomy

    DEFF Research Database (Denmark)

    Lauridsen, Henrik; Hansen, Kasper; Wang, Tobias

    2011-01-01

    allow for creation of three-dimensional representations that can be of considerable value in the dissemination of anatomical studies. In this methodological review, we present our experiences using MRI, CT and mCT to create advanced representation of animal anatomy, including bones, inner organs...... and blood vessels in a variety of animals, including fish, amphibians, reptiles, mammals, and spiders. The images have a similar quality to most traditional anatomical drawings and are presented together with interactive movies of the anatomical structures, where the object can be viewed from different...... angles. Given that clinical scanners found in the majority of larger hospitals are fully suitable for these purposes, we encourage biologists to take advantage of these imaging techniques in creation of three-dimensional graphical representations of internal structures...

  13. Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D J; Smith, R F; Bolme, C; Celliers, P; Collins, G

    2011-03-23

    We describe the data analysis procedures for an emerging interferometric technique for measuring motion across a two-dimensional image at a moment in time, i.e. a snapshot 2d-VISAR. Velocity interferometers (VISAR) measuring target motion to high precision have been an important diagnostic in shockwave physics for many years Until recently, this diagnostic has been limited to measuring motion at points or lines across a target. We introduce an emerging interferometric technique for measuring motion across a two-dimensional image, which could be called a snapshot 2d-VISAR. If a sufficiently fast movie camera technology existed, it could be placed behind a traditional VISAR optical system and record a 2d image vs time. But since that technology is not yet available, we use a CCD detector to record a single 2d image, with the pulsed nature of the illumination providing the time resolution. Consequently, since we are using pulsed illumination having a coherence length shorter than the VISAR interferometer delay ({approx}0.1 ns), we must use the white light velocimetry configuration to produce fringes with significant visibility. In this scheme, two interferometers (illuminating, detecting) having nearly identical delays are used in series, with one before the target and one after. This produces fringes with at most 50% visibility, but otherwise has the same fringe shift per target motion of a traditional VISAR. The 2d-VISAR observes a new world of information about shock behavior not readily accessible by traditional point or 1d-VISARS, simultaneously providing both a velocity map and an 'ordinary' snapshot photograph of the target. The 2d-VISAR has been used to observe nonuniformities in NIF related targets (polycrystalline diamond, Be), and in Si and Al.

  14. A fast image reconstruction technique based on ART

    International Nuclear Information System (INIS)

    Zhang Shunli; Zhang Dinghua; Wang Kai; Huang Kuidong; Li Weibin

    2007-01-01

    Algebraic Reconstruction Technique (ART) is an iterative method for image reconstruction. Improving its reconstruction speed has been one of the important researching aspects of ART. For the simplified weight coefficients reconstruction model of ART, a fast grid traverse algorithm is proposed, which can determine the grid index by simple operations such as addition, subtraction and comparison. Since the weight coefficients are calculated at real time during iteration, large amount of storage is saved and the reconstruction speed is greatly increased. Experimental results show that the new algorithm is very effective and the reconstruction speed is improved about 10 times compared with the traditional algorithm. (authors)

  15. Automatic identification of corrosion damage using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bento, Mariana P.; Ramalho, Geraldo L.B.; Medeiros, Fatima N.S. de; Ribeiro, Elvis S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Medeiros, Luiz C.L. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper proposes a Nondestructive Evaluation (NDE) method for atmospheric corrosion detection on metallic surfaces using digital images. In this study, the uniform corrosion is characterized by texture attributes extracted from co-occurrence matrix and the Self Organizing Mapping (SOM) clustering algorithm. We present a technique for automatic inspection of oil and gas storage tanks and pipelines of petrochemical industries without disturbing their properties and performance. Experimental results are promising and encourage the possibility of using this methodology in designing trustful and robust early failure detection systems. (author)

  16. Elastography of the Breast: Imaging Techniques and Pitfalls in Interpretation

    International Nuclear Information System (INIS)

    Moon, Woo Kyung; Chang, Jung Min; Cho, Nariya

    2011-01-01

    Ultrasound (US) elastography is a tool that indicates the hardness of a lesion. Recent studies using elastography with freehand compression have shown similar diagnostic performance to conventional US in differentiating benign lesions from malignant breast masses. On the other hand, the acquired information is not quantitative, and the reliability of the imaging technique to correctly compress the tissue depends on the skill of the operator, resulting in substantial interobserver variability during data acquisition and interpretation. To overcome this, shear wave elastography was developed to provide quantitative information on the tissue elasticity. The system works by remotely inducing mechanical vibrations through the acoustic radiation force created by a focused US beam. This review discusses the principles and examination techniques of the two types of elastography systems and provides practical points to reduce the interobserver variability or errors during data acquisition and interpretation

  17. Radionuclide imaging of parathyroid tumors: historical perspectives and newer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Winzelberg, G.G.; Hydovitz, J.D.

    1985-04-01

    The increasing use of automated blood chemistry screens for serum calcium levels along with improved methods in measuring parathyroid hormone (PTH) levels have made the diagnosis of parathyroid disease a common clinical problem. Parathyroid adenomas account for the majority of primary hyperparathyroidism with diffuse hyperplasia and parathyroid carcinoma occurring less frequently. Early scintigraphic techniques to identify enlarged parathyroids used selenomethionine-75 which was considered to be incorporated into PTH. In general, the sensitivity of scanning the neck using this tracer was related to the size of the enlarged parathyroid, but in large series, the overall sensitivity was less than 50%. Recent work by Ferlin et al, using a Technetium-99m/Thallium-201 subtraction scintigraphic technique has yielded a sensitivity of 92% in identifying pathologically enlarged parathyroid glands. Winzelberg et al modified this technique to allow imaging the mediastinum plus simplifying the subtraction method. In a prospective study with high-resolution sonography, similar sensitivities and specificities were found with sonography and scintigraphy. Tl-201/Tc-99m pertechnetate subtraction scintigraphy appears to be an accurate technique in identifying pathologic parathyroid enlargement. Its ultimate role in the evaluation of patients with suspected hyperparathyroidism still needs to be determined. 37 references.

  18. STUDY OF IMAGE SEGMENTATION TECHNIQUES ON RETINAL IMAGES FOR HEALTH CARE MANAGEMENT WITH FAST COMPUTING

    Directory of Open Access Journals (Sweden)

    Srikanth Prabhu

    2012-02-01

    Full Text Available The role of segmentation in image processing is to separate foreground from background. In this process, the features become clearly visible when appropriate filters are applied on the image. In this paper emphasis has been laid on segmentation of biometric retinal images to filter out the vessels explicitly for evaluating the bifurcation points and features for diabetic retinopathy. Segmentation on images is performed by calculating ridges or morphology. Ridges are those areas in the images where there is sharp contrast in features. Morphology targets the features using structuring elements. Structuring elements are of different shapes like disk, line which is used for extracting features of those shapes. When segmentation was performed on retinal images problems were encountered during image pre-processing stage. Also edge detection techniques have been deployed to find out the contours of the retinal images. After the segmentation has been performed, it has been seen that artifacts of the retinal images have been minimal when ridge based segmentation technique was deployed. In the field of Health Care Management, image segmentation has an important role to play as it determines whether a person is normal or having any disease specially diabetes. During the process of segmentation, diseased features are classified as diseased one’s or artifacts. The problem comes when artifacts are classified as diseased ones. This results in misclassification which has been discussed in the analysis Section. We have achieved fast computing with better performance, in terms of speed for non-repeating features, when compared to repeating features.

  19. Automatic DNA Diagnosis for 1D Gel Electrophoresis Images using Bio-image Processing Technique.

    Science.gov (United States)

    Intarapanich, Apichart; Kaewkamnerd, Saowaluck; Shaw, Philip J; Ukosakit, Kittipat; Tragoonrung, Somvong; Tongsima, Sissades

    2015-01-01

    DNA gel electrophoresis is a molecular biology technique for separating different sizes of DNA fragments. Applications of DNA gel electrophoresis include DNA fingerprinting (genetic diagnosis), size estimation of DNA, and DNA separation for Southern blotting. Accurate interpretation of DNA banding patterns from electrophoretic images can be laborious and error prone when a large number of bands are interrogated manually. Although many bio-imaging techniques have been proposed, none of them can fully automate the typing of DNA owing to the complexities of migration patterns typically obtained. We developed an image-processing tool that automatically calls genotypes from DNA gel electrophoresis images. The image processing workflow comprises three main steps: 1) lane segmentation, 2) extraction of DNA bands and 3) band genotyping classification. The tool was originally intended to facilitate large-scale genotyping analysis of sugarcane cultivars. We tested the proposed tool on 10 gel images (433 cultivars) obtained from polyacrylamide gel electrophoresis (PAGE) of PCR amplicons for detecting intron length polymorphisms (ILP) on one locus of the sugarcanes. These gel images demonstrated many challenges in automated lane/band segmentation in image processing including lane distortion, band deformity, high degree of noise in the background, and bands that are very close together (doublets). Using the proposed bio-imaging workflow, lanes and DNA bands contained within are properly segmented, even for adjacent bands with aberrant migration that cannot be separated by conventional techniques. The software, called GELect, automatically performs genotype calling on each lane by comparing with an all-banding reference, which was created by clustering the existing bands into the non-redundant set of reference bands. The automated genotype calling results were verified by independent manual typing by molecular biologists. This work presents an automated genotyping tool from DNA

  20. Automatic DNA Diagnosis for 1D Gel Electrophoresis Images using Bio-image Processing Technique

    Science.gov (United States)

    2015-01-01

    Background DNA gel electrophoresis is a molecular biology technique for separating different sizes of DNA fragments. Applications of DNA gel electrophoresis include DNA fingerprinting (genetic diagnosis), size estimation of DNA, and DNA separation for Southern blotting. Accurate interpretation of DNA banding patterns from electrophoretic images can be laborious and error prone when a large number of bands are interrogated manually. Although many bio-imaging techniques have been proposed, none of them can fully automate the typing of DNA owing to the complexities of migration patterns typically obtained. Results We developed an image-processing tool that automatically calls genotypes from DNA gel electrophoresis images. The image processing workflow comprises three main steps: 1) lane segmentation, 2) extraction of DNA bands and 3) band genotyping classification. The tool was originally intended to facilitate large-scale genotyping analysis of sugarcane cultivars. We tested the proposed tool on 10 gel images (433 cultivars) obtained from polyacrylamide gel electrophoresis (PAGE) of PCR amplicons for detecting intron length polymorphisms (ILP) on one locus of the sugarcanes. These gel images demonstrated many challenges in automated lane/band segmentation in image processing including lane distortion, band deformity, high degree of noise in the background, and bands that are very close together (doublets). Using the proposed bio-imaging workflow, lanes and DNA bands contained within are properly segmented, even for adjacent bands with aberrant migration that cannot be separated by conventional techniques. The software, called GELect, automatically performs genotype calling on each lane by comparing with an all-banding reference, which was created by clustering the existing bands into the non-redundant set of reference bands. The automated genotype calling results were verified by independent manual typing by molecular biologists. Conclusions This work presents an

  1. Imaging Techniques for Clinical Burn Assessment with a Focus on Multispectral Imaging.

    Science.gov (United States)

    Thatcher, Jeffrey E; Squiers, John J; Kanick, Stephen C; King, Darlene R; Lu, Yang; Wang, Yulin; Mohan, Rachit; Sellke, Eric W; DiMaio, J Michael

    2016-08-01

    Significance: Burn assessments, including extent and severity, are some of the most critical diagnoses in burn care, and many recently developed imaging techniques may have the potential to improve the accuracy of these evaluations. Recent Advances: Optical devices, telemedicine, and high-frequency ultrasound are among the highlights in recent burn imaging advancements. We present another promising technology, multispectral imaging (MSI), which also has the potential to impact current medical practice in burn care, among a variety of other specialties. Critical Issues: At this time, it is still a matter of debate as to why there is no consensus on the use of technology to assist burn assessments in the United States. Fortunately, the availability of techniques does not appear to be a limitation. However, the selection of appropriate imaging technology to augment the provision of burn care can be difficult for clinicians to navigate. There are many technologies available, but a comprehensive review summarizing the tissue characteristics measured by each technology in light of aiding clinicians in selecting the proper device is missing. This would be especially valuable for the nonburn specialists who encounter burn injuries. Future Directions: The questions of when burn assessment devices are useful to the burn team, how the various imaging devices work, and where the various burn imaging technologies fit into the spectrum of burn care will continue to be addressed. Technologies that can image a large surface area quickly, such as thermography or laser speckle imaging, may be suitable for initial burn assessment and triage. In the setting of presurgical planning, ultrasound or optical microscopy techniques, including optical coherence tomography, may prove useful. MSI, which actually has origins in burn care, may ultimately meet a high number of requirements for burn assessment in routine clinical use.

  2. Performance evaluation of image enhancement techniques on a digital image-intensifier

    NARCIS (Netherlands)

    Dijk, J.; Bijl, P.; Bouma, H.

    2009-01-01

    Recently new techniques for night-vision cameras are developed. Digital image-intensifiers are becoming available on the market. Also, so-called EMCCD cameras are developed, which may even be able to record color information about the scene. However, in low-light situations all night-vision imagery

  3. A post-processing technique for cranial CT image identification.

    Science.gov (United States)

    Wang, Jian-Jun; Wang, Jun-Ling; Chen, Yan-Ling; Li, Wen-Sheng

    2012-09-10

    A major challenge in radiographic identification is the inconsistent orientation between clinical (ante-mortem, AM) and post-mortem (PM) radiographs. The objectivity and accuracy of radiological identification would be greatly enhanced by post-processing techniques that allow quantitative comparison of PM CT data in the same orientation as the AM CT data. We applied a post-processing technique to reposition a multislice computed tomography (MSCT) scan for spatial registration with a CT radiograph from the same patient. A second set of MSCT images from different individuals served as the non-matched control group. The consistency in radiographic positioning eliminated subjectivity in the comparison and identification process because the radiograph superposition provided objective evidence that confirmed the identification with fine detail. A quantitative comparison with statistical validation was achieved by measuring a set of 14 landmarks from the images. Discrimination of identity based on logistic regression analysis of the earlier CT patient scans (the AM group) versus subsequent MSCT scans (the PM group) was objective and reliable. This quantitative comparison depends less on subjective judgment and the experience of the examiner, and so may meet legal standards. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Techniques for RNA in vivo imaging in plants.

    Science.gov (United States)

    Tilsner, Jens

    2015-04-01

    Since the discovery of small RNAs and RNA silencing, RNA biology has taken a centre stage in cell and developmental biology. Small RNAs, but also mRNAs and other types of cellular and viral RNAs are processed at specific subcellular localizations. To fully understand cellular RNA metabolism and the various processes influenced by it, techniques are required that permit the sequence-specific tracking of RNAs in living cells. A variety of methods for RNA visualization have been developed since the 1990s, but plant cells pose particular challenges and not all approaches are applicable to them. On the other hand, plant RNA metabolism is particularly diverse and RNAs are even transported between cells, so RNA imaging can potentially provide many valuable insights into plant function at the cellular and tissue level. This Short Review briefly introduces the currently available techniques for plant RNA in vivo imaging and discusses their suitability for different biological questions. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  5. A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-01-01

    Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against

  6. A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Wendy [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Ren, Lei, E-mail: lei.ren@duke.edu [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Zhang, You [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Chang, Zheng; Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2016-06-01

    Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against

  7. Time-Domain Fluorescence Lifetime Imaging Techniques Suitable for Solid-State Imaging Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Robert K. Henderson

    2012-05-01

    Full Text Available We have successfully demonstrated video-rate CMOS single-photon avalanche diode (SPAD-based cameras for fluorescence lifetime imaging microscopy (FLIM by applying innovative FLIM algorithms. We also review and compare several time-domain techniques and solid-state FLIM systems, and adapt the proposed algorithms for massive CMOS SPAD-based arrays and hardware implementations. The theoretical error equations are derived and their performances are demonstrated on the data obtained from 0.13 μm CMOS SPAD arrays and the multiple-decay data obtained from scanning PMT systems. In vivo two photon fluorescence lifetime imaging data of FITC-albumin labeled vasculature of a P22 rat carcinosarcoma (BD9 rat window chamber are used to test how different algorithms perform on bi-decay data. The proposed techniques are capable of producing lifetime images with enough contrast.

  8. Ultrasonic technique for imaging tissue vibrations: preliminary results.

    Science.gov (United States)

    Sikdar, Siddhartha; Beach, Kirk W; Vaezy, Shahram; Kim, Yongmin

    2005-02-01

    We propose an ultrasound (US)-based technique for imaging vibrations in the blood vessel walls and surrounding tissue caused by eddies produced during flow through narrowed or punctured arteries. Our approach is to utilize the clutter signal, normally suppressed in conventional color flow imaging, to detect and characterize local tissue vibrations. We demonstrate the feasibility of visualizing the origin and extent of vibrations relative to the underlying anatomy and blood flow in real-time and their quantitative assessment, including measurements of the amplitude, frequency and spatial distribution. We present two signal-processing algorithms, one based on phase decomposition and the other based on spectral estimation using eigen decomposition for isolating vibrations from clutter, blood flow and noise using an ensemble of US echoes. In simulation studies, the computationally efficient phase-decomposition method achieved 96% sensitivity and 98% specificity for vibration detection and was robust to broadband vibrations. Somewhat higher sensitivity (98%) and specificity (99%) could be achieved using the more computationally intensive eigen decomposition-based algorithm. Vibration amplitudes as low as 1 mum were measured accurately in phantom experiments. Real-time tissue vibration imaging at typical color-flow frame rates was implemented on a software-programmable US system. Vibrations were studied in vivo in a stenosed femoral bypass vein graft in a human subject and in a punctured femoral artery and incised spleen in an animal model.

  9. Inside out: modern imaging techniques to reveal animal anatomy.

    Science.gov (United States)

    Lauridsen, Henrik; Hansen, Kasper; Wang, Tobias; Agger, Peter; Andersen, Jonas L; Knudsen, Peter S; Rasmussen, Anne S; Uhrenholt, Lars; Pedersen, Michael

    2011-03-22

    Animal anatomy has traditionally relied on detailed dissections to produce anatomical illustrations, but modern imaging modalities, such as MRI and CT, now represent an enormous resource that allows for fast non-invasive visualizations of animal anatomy in living animals. These modalities also allow for creation of three-dimensional representations that can be of considerable value in the dissemination of anatomical studies. In this methodological review, we present our experiences using MRI, CT and μCT to create advanced representation of animal anatomy, including bones, inner organs and blood vessels in a variety of animals, including fish, amphibians, reptiles, mammals, and spiders. The images have a similar quality to most traditional anatomical drawings and are presented together with interactive movies of the anatomical structures, where the object can be viewed from different angles. Given that clinical scanners found in the majority of larger hospitals are fully suitable for these purposes, we encourage biologists to take advantage of these imaging techniques in creation of three-dimensional graphical representations of internal structures.

  10. Inside out: modern imaging techniques to reveal animal anatomy.

    Directory of Open Access Journals (Sweden)

    Henrik Lauridsen

    2011-03-01

    Full Text Available Animal anatomy has traditionally relied on detailed dissections to produce anatomical illustrations, but modern imaging modalities, such as MRI and CT, now represent an enormous resource that allows for fast non-invasive visualizations of animal anatomy in living animals. These modalities also allow for creation of three-dimensional representations that can be of considerable value in the dissemination of anatomical studies. In this methodological review, we present our experiences using MRI, CT and μCT to create advanced representation of animal anatomy, including bones, inner organs and blood vessels in a variety of animals, including fish, amphibians, reptiles, mammals, and spiders. The images have a similar quality to most traditional anatomical drawings and are presented together with interactive movies of the anatomical structures, where the object can be viewed from different angles. Given that clinical scanners found in the majority of larger hospitals are fully suitable for these purposes, we encourage biologists to take advantage of these imaging techniques in creation of three-dimensional graphical representations of internal structures.

  11. Assessment of tumors of the lung apex by imaging techniques

    International Nuclear Information System (INIS)

    Rueda, J.; Serrano, F.; Pain, M.I.; Rodriguez, F.

    1996-01-01

    The purpose of this study was to analyze the value of MR in the preoperative staging of tumors of the lung apex and detection of local invasion of adjacent structures to determine its influence on the therapeutic approach. We obtained plain X-ray images in two planes, as well as CT and Mr images, in 12 patients with Pan coast tumor in whom there was surgical (n=8) or clinical (n=4) evidence of invasion. The objective was to assess local infiltration of brain stem and chest wall soft tissue, enveloping of the subclavian artery, substantial involvement of the brachial plexus and destruction of the vertebral body. In our series, MR was superior to the other imaging techniques in predicting the involvement of the structures surrounding the tumor. In conclusion, MR should be performed in a patient diagnosed by plain radiography as having an apical tumors to assess local tumor extension, while CT should be done to detect mediastinal lymph node involvement and distant metastases. 19 refs

  12. Distributed Source Coding Techniques for Lossless Compression of Hyperspectral Images

    Directory of Open Access Journals (Sweden)

    Marco Grangetto

    2007-01-01

    Full Text Available This paper deals with the application of distributed source coding (DSC theory to remote sensing image compression. Although DSC exhibits a significant potential in many application fields, up till now the results obtained on real signals fall short of the theoretical bounds, and often impose additional system-level constraints. The objective of this paper is to assess the potential of DSC for lossless image compression carried out onboard a remote platform. We first provide a brief overview of DSC of correlated information sources. We then focus on onboard lossless image compression, and apply DSC techniques in order to reduce the complexity of the onboard encoder, at the expense of the decoder's, by exploiting the correlation of different bands of a hyperspectral dataset. Specifically, we propose two different compression schemes, one based on powerful binary error-correcting codes employed as source codes, and one based on simpler multilevel coset codes. The performance of both schemes is evaluated on a few AVIRIS scenes, and is compared with other state-of-the-art 2D and 3D coders. Both schemes turn out to achieve competitive compression performance, and one of them also has reduced complexity. Based on these results, we highlight the main issues that are still to be solved to further improve the performance of DSC-based remote sensing systems.

  13. Real-time windowing in imaging radar using FPGA technique

    Science.gov (United States)

    Ponomaryov, Volodymyr I.; Escamilla-Hernandez, Enrique

    2005-02-01

    The imaging radar uses the high frequency electromagnetic waves reflected from different objects for estimating of its parameters. Pulse compression is a standard signal processing technique used to minimize the peak transmission power and to maximize SNR, and to get a better resolution. Usually the pulse compression can be achieved using a matched filter. The level of the side-lobes in the imaging radar can be reduced using the special weighting function processing. There are very known different weighting functions: Hamming, Hanning, Blackman, Chebyshev, Blackman-Harris, Kaiser-Bessel, etc., widely used in the signal processing applications. Field Programmable Gate Arrays (FPGAs) offers great benefits like instantaneous implementation, dynamic reconfiguration, design, and field programmability. This reconfiguration makes FPGAs a better solution over custom-made integrated circuits. This work aims at demonstrating a reasonably flexible implementation of FM-linear signal and pulse compression using Matlab, Simulink, and System Generator. Employing FPGA and mentioned software we have proposed the pulse compression design on FPGA using classical and novel windows technique to reduce the side-lobes level. This permits increasing the detection ability of the small or nearly placed targets in imaging radar. The advantage of FPGA that can do parallelism in real time processing permits to realize the proposed algorithms. The paper also presents the experimental results of proposed windowing procedure in the marine radar with such the parameters: signal is linear FM (Chirp); frequency deviation DF is 9.375MHz; the pulse width T is 3.2μs taps number in the matched filter is 800 taps; sampling frequency 253.125*106 MHz. It has been realized the reducing of side-lobes levels in real time permitting better resolution of the small targets.

  14. Advances in high-resolution imaging--techniques for three-dimensional imaging of cellular structures.

    Science.gov (United States)

    Lidke, Diane S; Lidke, Keith A

    2012-06-01

    A fundamental goal in biology is to determine how cellular organization is coupled to function. To achieve this goal, a better understanding of organelle composition and structure is needed. Although visualization of cellular organelles using fluorescence or electron microscopy (EM) has become a common tool for the cell biologist, recent advances are providing a clearer picture of the cell than ever before. In particular, advanced light-microscopy techniques are achieving resolutions below the diffraction limit and EM tomography provides high-resolution three-dimensional (3D) images of cellular structures. The ability to perform both fluorescence and electron microscopy on the same sample (correlative light and electron microscopy, CLEM) makes it possible to identify where a fluorescently labeled protein is located with respect to organelle structures visualized by EM. Here, we review the current state of the art in 3D biological imaging techniques with a focus on recent advances in electron microscopy and fluorescence super-resolution techniques.

  15. Final Project Report: Imaging Fault Zones Using a Novel Elastic Reverse-Time Migration Imaging Technique

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ting [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tan, Sirui [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lin, Youzuo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gao, Kai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-10

    Imaging fault zones and fractures is crucial for geothermal operators, providing important information for reservoir evaluation and management strategies. However, there are no existing techniques available for directly and clearly imaging fault zones, particularly for steeply dipping faults and fracture zones. In this project, we developed novel acoustic- and elastic-waveform inversion methods for high-resolution velocity model building. In addition, we developed acoustic and elastic reverse-time migration methods for high-resolution subsurface imaging of complex subsurface structures and steeply-dipping fault/fracture zones. We first evaluated and verified the improved capabilities of our newly developed seismic inversion and migration imaging methods using synthetic seismic data. Our numerical tests verified that our new methods directly image subsurface fracture/fault zones using surface seismic reflection data. We then applied our novel seismic inversion and migration imaging methods to a field 3D surface seismic dataset acquired at the Soda Lake geothermal field using Vibroseis sources. Our migration images of the Soda Lake geothermal field obtained using our seismic inversion and migration imaging algorithms revealed several possible fault/fracture zones. AltaRock Energy, Inc. is working with Cyrq Energy, Inc. to refine the geologic interpretation at the Soda Lake geothermal field. Trenton Cladouhos, Senior Vice President R&D of AltaRock, was very interested in our imaging results of 3D surface seismic data from the Soda Lake geothermal field. He planed to perform detailed interpretation of our images in collaboration with James Faulds and Holly McLachlan of University of Nevada at Reno. Using our high-resolution seismic inversion and migration imaging results can help determine the optimal locations to drill wells for geothermal energy production and reduce the risk of geothermal exploration.

  16. Dual-energy imaging of the chest: optimization of image acquisition techniques for the 'bone-only' image.

    Science.gov (United States)

    Shkumat, N A; Siewerdsen, J H; Richard, S; Paul, N S; Yorkston, J; Van Metter, R

    2008-02-01

    Experiments were conducted to determine optimal acquisition techniques for bone image decompositions for a prototype dual-energy (DE) imaging system. Technique parameters included kVp pair (denoted [kVp(L)/kVp(H)]) and dose allocation (the proportion of dose in low- and high-energy projections), each optimized to provide maximum signal difference-to-noise ratio in DE images. Experiments involved a chest phantom representing an average patient size and containing simulated ribs and lung nodules. Low- and high-energy kVp were varied from 60-90 and 120-150 kVp, respectively. The optimal kVp pair was determined to be [60/130] kVp, with image quality showing a strong dependence on low-kVp selection. Optimal dose allocation was approximately 0.5-i.e., an equal dose imparted by the low- and high-energy projections. The results complement earlier studies of optimal DE soft-tissue image acquisition, with differences attributed to the specific imaging task. Together, the results help to guide the development and implementation of high-performance DE imaging systems, with applications including lung nodule detection and diagnosis, pneumothorax identification, and musculoskeletal imaging (e.g., discrimination of rib fractures from metastasis).

  17. Radiation exposure to patients from image guidance procedures and techniques to reduce the imaging dose.

    Science.gov (United States)

    Ding, George X; Munro, Peter

    2013-07-01

    To compare imaging doses from MV images, kV radiographs, and kV-CBCT and describe methods to reduce the dose to patient's organs using existing on-board imaging devices. Monte Carlo techniques were used to simulate kV X-ray sources. The kV image doses to a variety of patient anatomies were calculated by using the simulated realistic sources to deposit dose in patient CT images. For MV imaging, the doses for the same patients were calculated using a commercial treatment planning system. Portal imaging results in the largest dose to anatomic structures, followed by Varian OBI CBCT, Varian TrueBeam CBCT and then kV radiographs. The imaging doses for the 50% volume from the DVHs, D50, to the eyes for representative head images are 4.3-4.8cGy; 0.05-0.06cGy; 0.04-0.05cGy; and, 0.12cGy; D50 to the bladder for representative pelvis images are 3.3cGy; 1.6cGy; 1.0cGy; and, 0.07cGy; while D50 to the heart for representative thorax images are 3.5cGy; 0.42cGy; 0.2cGy; and, 0.07cGy; when using portal imaging, OBI kV-CBCT scans, TrueBeam kV-CBCT scans and kV radiographs, respectively. The orientation of the kV beam can affect organ dose. For example, D50 to the eyes can be reduced from 0.12cGy using AP and right lateral radiographs to 0.008-0.017cGy when using PA and right lateral radiographs. In addition, organ exposures can be further reduced to 15-70% of their original values with the use of a full-fan, bow-tie filter for kV radiographs. In contrast, organ doses increase by a factor of ∼2-4 if bow-tie filters are not used during kV-CBCT acquisitions. Current on-board kV imaging devices result in much lower imaging doses compared to MV imagers even taking into account of higher bone dose from kV X-rays. And a variety of approaches are available to significantly reduce the image doses. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. Technical study of Germolles’ wall paintings: the inputof imaging technique

    Directory of Open Access Journals (Sweden)

    Christian Degrigny

    2016-11-01

    Full Text Available The Château de Germolles is one of the rare palace in France dating from the 14th century. The noble floor is decorated with wall paintings that are a unique example of courtly love spirit that infused the princely courts of the time. After being concealed sometime in the 19th century, the paintings were rediscovered and uncovered in the middle of the 20th century and partly restored at the end of the 1990s. No scientific documentation accompanied these interventions and important questions, such as the level of authenticity of the mural decorations and the original painting technique(s used in the medieval times remained unanswered. The combined scientific and financial supports of COSCH Cost Action and DRAC-Burgundy enabled to study Germolles’ wall paintings using some of the most innovative imaging and analytical techniques and to address some of the questions raised. The study provided significant information on the material used in the medieval times and on the conservation condition of the paintings. The data collected is vast and varied and exposed the owners of the property to the challenges of data management.

  19. Recent developments at JPL in the application of digital image processing techniques to astronomical images

    Science.gov (United States)

    Lorre, J. J.; Lynn, D. J.; Benton, W. D.

    1976-01-01

    Several techniques of a digital image-processing nature are illustrated which have proved useful in visual analysis of astronomical pictorial data. Processed digital scans of photographic plates of Stephans Quintet and NGC 4151 are used as examples to show how faint nebulosity is enhanced by high-pass filtering, how foreground stars are suppressed by linear interpolation, and how relative color differences between two images recorded on plates with different spectral sensitivities can be revealed by generating ratio images. Analyses are outlined which are intended to compensate partially for the blurring effects of the atmosphere on images of Stephans Quintet and to obtain more detailed information about Saturn's ring structure from low- and high-resolution scans of the planet and its ring system. The employment of a correlation picture to determine the tilt angle of an average spectral line in a low-quality spectrum is demonstrated for a section of the spectrum of Uranus.

  20. Probabilistic images (PBIS): A concise image representation technique for multiple parameters

    Energy Technology Data Exchange (ETDEWEB)

    Wu, L.C.; Yeh, S.H.; Chen, Z.; Liu, R.S.

    1984-01-01

    Based on m parametric images (PIs) derived from a dynamic series (DS), each pixel of DS is regarded as an m-dimensional vector. Given one set of normal samples (pixels) N and another of abnormal samples A, probability density functions (pdfs) of both sets are estimated. Any unknown sample is classified into N or A by calculating the probability of its being in the abnormal set using the Bayes' theorem. Instead of estimating the multivariate pdfs, a distance ratio transformation is introduced to map the m-dimensional sample space to one dimensional Euclidean space. Consequently, the image that localizes the regional abnormalities is characterized by the probability of being abnormal. This leads to the new representation scheme of PBIs. Tc-99m HIDA study for detecting intrahepatic lithiasis (IL) was chosen as an example of constructing PBI from 3 parameters derived from DS and such a PBI was compared with those 3 PIs, namely, retention ratio image (RRI), peak time image (TNMAX) and excretion mean transit time image (EMTT). 32 normal subjects and 20 patients with proved IL were collected and analyzed. The resultant sensitivity and specificity of PBI were 97% and 98% respectively. They were superior to those of any of the 3 PIs: RRI (94/97), TMAX (86/88) and EMTT (94/97). Furthermore, the contrast of PBI was much better than that of any other image. This new image formation technique, based on multiple parameters, shows the functional abnormalities in a structural way. Its good contrast makes the interpretation easy. This technique is powerful compared to the existing parametric image method.

  1. Probabilistic images (PBIS): A concise image representation technique for multiple parameters

    International Nuclear Information System (INIS)

    Wu, L.C.; Yeh, S.H.; Chen, Z.; Liu, R.S.

    1984-01-01

    Based on m parametric images (PIs) derived from a dynamic series (DS), each pixel of DS is regarded as an m-dimensional vector. Given one set of normal samples (pixels) N and another of abnormal samples A, probability density functions (pdfs) of both sets are estimated. Any unknown sample is classified into N or A by calculating the probability of its being in the abnormal set using the Bayes' theorem. Instead of estimating the multivariate pdfs, a distance ratio transformation is introduced to map the m-dimensional sample space to one dimensional Euclidean space. Consequently, the image that localizes the regional abnormalities is characterized by the probability of being abnormal. This leads to the new representation scheme of PBIs. Tc-99m HIDA study for detecting intrahepatic lithiasis (IL) was chosen as an example of constructing PBI from 3 parameters derived from DS and such a PBI was compared with those 3 PIs, namely, retention ratio image (RRI), peak time image (TNMAX) and excretion mean transit time image (EMTT). 32 normal subjects and 20 patients with proved IL were collected and analyzed. The resultant sensitivity and specificity of PBI were 97% and 98% respectively. They were superior to those of any of the 3 PIs: RRI (94/97), TMAX (86/88) and EMTT (94/97). Furthermore, the contrast of PBI was much better than that of any other image. This new image formation technique, based on multiple parameters, shows the functional abnormalities in a structural way. Its good contrast makes the interpretation easy. This technique is powerful compared to the existing parametric image method

  2. Phase image encryption of colored images using double random phase encoding technique in HSV color space

    Science.gov (United States)

    Joshi, Madhusudan; Shakher, Chandra; Singh, Kehar

    2009-09-01

    A double random phase encoding based digital phase encryption technique for colored images is proposed in the Fourier domain. The RGB input image is brought to HSV color space and then converted into phase, prior to the encryption. In the decryption process the HSV image is and converted back to the RGB format. The random phase codes used during encryption are prepared by stacking three two-dimensional random phase masks. These random phase codes serve as keys for encryption and decryption. The proposed technique carries all the advantages of phase encryption and is supposedly three-dimensional in nature. Robustness of the technique is analyzed against the variations in random phase codes and shuffling of the random phase masks of a given phase code. Performance of the scheme is also verified against occlusion of Fourier plane random phase code as well as the encrypted image. Effects of noise attacks and attacks using partial windows of correct random phase codes have also been checked. Digital simulations are presented to support the idea.

  3. In Vivo Imaging of Nitric Oxide by Magnetic Resonance Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Rakesh Sharma

    2014-01-01

    Full Text Available Nitric oxide (NO biosensors are novel tools for real-time bioimaging of tissue oxygen changes and physiological monitoring of tissue vasculature. Nitric oxide behavior further enhances its role in mapping signal transduction at the molecular level. Spectrometric electron paramagnetic resonance (EPR and fluorometric imaging are well known techniques with the potential for in vivo bioimaging of NO. In tissues, NO is a specific target of nitrosyl compounds for chemical reaction, which provides a unique opportunity for application of newly identified NO biosensors. However, the accuracy and sensitivity of NO biosensors still need to be improved. Another potential magnetic resonance technique based on short term NO effects on proton relaxation enhancement is magnetic resonance imaging (MRI, and some NO biosensors may be used as potent imaging contrast agents for measurement of tumor size by MRI combined with fluorescent imaging. The present review provides supporting information regarding the possible use of nitrosyl compounds as NO biosensors in MRI and fluorescent bioimaging showing their measurement limitations and quantitative accuracy. These new approaches open a perspective regarding bioimaging of NO and the in vivo elucidation of NO effects by magnetic resonance techniques.

  4. Study of Ultrasound Imaging Technique for Diagnosing Osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. J.; Han, S. M. [Kyunghee University, Seoul (Korea, Republic of); Lee, J. H.; Lee, M. R. [Pusan National University, Busan (Korea, Republic of)

    2002-08-15

    Ultrasonic has been proposed as an attractive means of detecting bone loss. There have been several commercial ultrasound devices developed for measuring the heel to predict fracture at other bones. However, these devices select only single point of heel bone as measurement site. It causes poor assessment of bone quality due to the error of transducer positioning. In an effort to improve current ultrasound systems, we evaluated the linear scanning method which provides better prediction of bone quality and an accurate image of bone shape. The system used in this study biaxially scans a heel bone using automated linear scanning technique. The results demonstrated that the values of ultrasound parameters varied with different positions within bone specimen. It has been also found that the linear scanning method could better predict bone quality, eliminating the error of transducer positioning

  5. Exploring the Nuclear Landscape by Image Reconstruction Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Morales, I.; Mendoza T, J.; Lopez V, J.C.; Barea, J.; Hirsch, J.G.; Frank, A. [Instituto de Ciencias Nucleares, UNAM, AP 70-543, 04510 Mexico D.F. (Mexico); Velazquez, V. [Departamento de Fisica, Facultad de Ciencias, UNAM, AP 70-348, 04511 Mexico D.F. (Mexico)]. e-mail: frank@nucleares.unam.mx

    2007-12-15

    In spite of the development of ever more elaborate techniques for the calculation of nuclear properties, the calculation of the most basic property of atomic nuclei, their mass, still represents a challenging task. The differences between measured masses and Liquid Drop Model (LDM) predictions have well known regularities. They contain information related to shell closures, nuclear deformation and the residual nuclear interactions, and display a well defined pattern, which can be viewed as a two-dimensional image. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. Employing a Fourier transform deconvolution method these masses can be predicted. Measured masses are reconstructed with and r.m.s. error of less than 100 keV. Potential applications of the present approach are outlined. (Author)

  6. Staging of malignant lymphomas - lymphography as complementary imaging technique

    International Nuclear Information System (INIS)

    Rieden, K.; Lellig, U.; Wannenmacher, M.

    1991-01-01

    Abdominal CT and subsequent lymphography were performed in 44 patients staged for malignant lymphoma (25 Hodgkin's disease, 19 Non-Hodgkin lymphoma). All patients had abdominal CT findings which were equivocal or not in agreement with clinical symptoms. In 79.5% of all patients (80% HL, 79% NHL) both examinations agreed if there was no lymph node involvement. There was disagreement in 5 patients with Hodgkin's disease and in 4 patients with Non-Hodgkin lymphoma. Most discrepancies consisted of a normal or equivocal CT in combination with an abnormal lymphogram. In 2 patients, CT was misinterpreted as showing involved lymph nodes whereas subsequent lymphography was normal. It is concluded that lymphography is indicated in the initial staging of malignant lymphomas as a complementary imaging technique, since the combination of the two methods yields improved diagnostic information. (orig.) [de

  7. Three-dimensional particle image velocimetry measurement technique

    International Nuclear Information System (INIS)

    Hassan, Y.A.; Seeley, C.H.; Henderson, J.A.; Schmidl, W.D.

    2004-01-01

    The experimental flow visualization tool, Particle Image Velocimetry (PIV), is being used to determine the velocity field in two-dimensional fluid flows. In the past few years, the technique has been improved to allow the capture of flow fields in three dimensions. This paper describes changes which were made to two existing two-dimensional tracking algorithms to enable them to track three-dimensional PIV data. Results of the tests performed on these three-dimensional routines with synthetic data are presented. Experimental data was also used to test the tracking algorithms. The test setup which was used to acquire the three-dimensional experimental data is described, along with the results from both of the tracking routines which were used to analyze the experimental data. (author)

  8. Extending Driving Vision Based on Image Mosaic Technique

    Directory of Open Access Journals (Sweden)

    Chen Deng

    2017-01-01

    Full Text Available Car cameras have been used extensively to assist driving by make driving visible. However, due to the limitation of the Angle of View (AoV, the dead zone still exists, which is a primary origin of car accidents. In this paper, we introduce a system to extend the vision of drivers to 360 degrees. Our system consists of four wide-angle cameras, which are mounted at different sides of a car. Although the AoV of each camera is within 180 degrees, relying on the image mosaic technique, our system can seamlessly integrate 4-channel videos into a panorama video. The panorama video enable drivers to observe everywhere around a car as far as three meters from a top view. We performed experiments in a laboratory environment. Preliminary results show that our system can eliminate vision dead zone completely. Additionally, the real-time performance of our system can satisfy requirements for practical use.

  9. Valve Calcification in Aortic Stenosis: Etiology and Diagnostic Imaging Techniques

    Directory of Open Access Journals (Sweden)

    María Manuela Izquierdo-Gómez

    2017-01-01

    Full Text Available Aortic stenosis is the most common valvulopathy in the Western world. Its prevalence has increased significantly in recent years due to population aging; hence, up to 8% of westerners above the age of 84 now have severe aortic stenosis (Lindroos et al., 1993. This causes increased morbidity and mortality and therein lies the importance of adequate diagnosis and stratification of the degree of severity which allows planning the best therapeutic option in each case. Long understood as a passive age-related degenerative process, it is now considered a rather more complex entity involving mechanisms and factors similar to those of atherosclerosis (Stewart et al., 1997. In this review, we summarize the pathophysiological mechanisms underlying the onset and progression of the disease and analyze the current role of cardiac imaging techniques for diagnosis.

  10. Importance of ultrasonic holography as imaging technique of material faults

    International Nuclear Information System (INIS)

    Schmitz, V.

    1978-01-01

    In ultra-sound testing of thick-wall components the reconstruction of shape and position of material faults stands in the foreground. Ultra-sound holography allows imaging of this kind. The principle of this technique is to completely measure the amount and phase of a sound field arising from the fault location on the surface of the material-piece. The quantity is measured as a complex quantity. To accomplish this, ultra-sound holography works with monochromatic burst-signals. The recording of phase and amplitude formation can be made optically by means of a film carrier as well as numerically in a computer. Corresponding to this fact the reconstruction takes place by means of a laser beam or by means of mathematical formalisms in the computer. Both the methods are realized today and are applied in destruction-free testing. (orig./DG) [de

  11. The probabilistic image: a concise image representation technique for multiple parameters

    International Nuclear Information System (INIS)

    Wu, L.C.; Yeh, S.H.; Liu, R.S.; National Yang-Mills Medical Coll., Taipei, Taiwan); Chen, Z.

    1984-01-01

    In scintiscanning studies, an attempt has been made to use multiple parametric information to evaluate functional abnormalities in human organs, using the probabilistic domain instead of the parametric domain to present single or multiple parameters in one image. The construction of such a probabilistic image (PBI) has been illustrated from a 99 Tcsup(m)-HIDA study in 32 normal subjects and in 20 patients with intrahepatic lithiasis. The results show that this technique shows the functional abnormalities in a structural format with a good contrast and probabilistic sense. (U.K.)

  12. The study of CT pulmonary functional imaging technique

    International Nuclear Information System (INIS)

    Zhang Weihong; Liu Yuqing; Mou Weibin

    2001-01-01

    were detected to correlate with pulmonary function test parameters. Conclusion: Spiral CT scanning at full inspiratory and expiratory phase can provide pulmonary functional as well as anatomic information. The new imaging technique, therefore, is an effective method for quantitative pulmonary function study

  13. BATMAN: Bayesian Technique for Multi-image Analysis

    Science.gov (United States)

    Casado, J.; Ascasibar, Y.; García-Benito, R.; Guidi, G.; Choudhury, O. S.; Bellocchi, E.; Sánchez, S. F.; Díaz, A. I.

    2017-04-01

    This paper describes the Bayesian Technique for Multi-image Analysis (BATMAN), a novel image-segmentation technique based on Bayesian statistics that characterizes any astronomical data set containing spatial information and performs a tessellation based on the measurements and errors provided as input. The algorithm iteratively merges spatial elements as long as they are statistically consistent with carrying the same information (I.e. identical signal within the errors). We illustrate its operation and performance with a set of test cases including both synthetic and real integral-field spectroscopic data. The output segmentations adapt to the underlying spatial structure, regardless of its morphology and/or the statistical properties of the noise. The quality of the recovered signal represents an improvement with respect to the input, especially in regions with low signal-to-noise ratio. However, the algorithm may be sensitive to small-scale random fluctuations, and its performance in presence of spatial gradients is limited. Due to these effects, errors may be underestimated by as much as a factor of 2. Our analysis reveals that the algorithm prioritizes conservation of all the statistically significant information over noise reduction, and that the precise choice of the input data has a crucial impact on the results. Hence, the philosophy of BaTMAn is not to be used as a 'black box' to improve the signal-to-noise ratio, but as a new approach to characterize spatially resolved data prior to its analysis. The source code is publicly available at http://astro.ft.uam.es/SELGIFS/BaTMAn.

  14. Experimental validation of incomplete data CT image reconstruction techniques

    International Nuclear Information System (INIS)

    Eberhard, J.W.; Hsiao, M.L.; Tam, K.C.

    1989-01-01

    X-ray CT inspection of large metal parts is often limited by x-ray penetration problems along many of the ray paths required for a complete CT data set. In addition, because of the complex geometry of many industrial parts, manipulation difficulties often prevent scanning over some range of angles. CT images reconstructed from these incomplete data sets contain a variety of artifacts which limit their usefulness in part quality determination. Over the past several years, the authors' company has developed 2 new methods of incorporating a priori information about the parts under inspection to significantly improve incomplete data CT image quality. This work reviews the methods which were developed and presents experimental results which confirm the effectiveness of the techniques. The new methods for dealing with incomplete CT data sets rely on a priori information from part blueprints (in electronic form), outer boundary information from touch sensors, estimates of part outer boundaries from available x-ray data, and linear x-ray attenuation coefficients of the part. The two methods make use of this information in different fashions. The relative performance of the two methods in detecting various flaw types is compared. Methods for accurately registering a priori information with x-ray data are also described. These results are critical to a new industrial x-ray inspection cell built for inspection of large aircraft engine parts

  15. Imaging techniques for the assessment of fracture repair.

    Science.gov (United States)

    Augat, P; Morgan, E F; Lujan, T J; MacGillivray, T J; Cheung, W H

    2014-06-01

    Imaging of a healing fracture provides a non-invasive and often instructive reproduction of the fracture repair progress and the healing status of bone. However, the interpretation of this reproduction is often qualitative and provides only an indirect and surrogate measure of the mechanical stability of the healing fracture. Refinements of the available imaging techniques have been suggested to more accurately determine the healing status of bone. Plain radiographs provide the ability to determine the degree of bridging of the fracture gap and to quantify the amount of periosteal callus formation. Absorptiometric measures including dual X-ray absorptiometry and computed tomography provide quantitative information on the amount and the density of newly formed bone around the site of the fracture. To include the effect of spatial distribution of newly formed bone, finite element models of healing fracture can be employed to estimate its load bearing capacity. Ultrasound technology not only avoids radiation doses to the patients but also provides the ability to additionally measure vascularity in the surrounding soft tissue of the fracture and in the fracture itself. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Digital Image Processing Technique for Breast Cancer Detection

    Science.gov (United States)

    Guzmán-Cabrera, R.; Guzmán-Sepúlveda, J. R.; Torres-Cisneros, M.; May-Arrioja, D. A.; Ruiz-Pinales, J.; Ibarra-Manzano, O. G.; Aviña-Cervantes, G.; Parada, A. González

    2013-09-01

    Breast cancer is the most common cause of death in women and the second leading cause of cancer deaths worldwide. Primary prevention in the early stages of the disease becomes complex as the causes remain almost unknown. However, some typical signatures of this disease, such as masses and microcalcifications appearing on mammograms, can be used to improve early diagnostic techniques, which is critical for women’s quality of life. X-ray mammography is the main test used for screening and early diagnosis, and its analysis and processing are the keys to improving breast cancer prognosis. As masses and benign glandular tissue typically appear with low contrast and often very blurred, several computer-aided diagnosis schemes have been developed to support radiologists and internists in their diagnosis. In this article, an approach is proposed to effectively analyze digital mammograms based on texture segmentation for the detection of early stage tumors. The proposed algorithm was tested over several images taken from the digital database for screening mammography for cancer research and diagnosis, and it was found to be absolutely suitable to distinguish masses and microcalcifications from the background tissue using morphological operators and then extract them through machine learning techniques and a clustering algorithm for intensity-based segmentation.

  17. MR fingerprinting using the quick echo splitting NMR imaging technique.

    Science.gov (United States)

    Jiang, Yun; Ma, Dan; Jerecic, Renate; Duerk, Jeffrey; Seiberlich, Nicole; Gulani, Vikas; Griswold, Mark A

    2017-03-01

    The purpose of the study is to develop a quantitative method for the relaxation properties with a reduced radio frequency (RF) power deposition by combining magnetic resonance fingerprinting (MRF) technique with quick echo splitting NMR imaging technique (QUEST). A QUEST-based MRF sequence was implemented to acquire high-order echoes by increasing the gaps between RF pulses. Bloch simulations were used to calculate a dictionary containing the range of physically plausible signal evolutions using a range of T 1 and T 2 values based on the pulse sequence. MRF-QUEST was evaluated by comparing to the results of spin-echo methods. The specific absorption rate (SAR) of MRF-QUEST was compared with the clinically available methods. MRF-QUEST quantifies the relaxation properties with good accuracy at the estimated head SAR of 0.03 W/kg. T 1 and T 2 values estimated by MRF-QUEST are in good agreement with the traditional methods. The combination of the MRF and the QUEST provides an accurate quantification of T 1 and T 2 simultaneously with reduced RF power deposition. The resulting lower SAR may provide a new acquisition strategy for MRF when RF energy deposition is problematic. Magn Reson Med 77:979-988, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  18. Measurement of spatial correlation functions using image processing techniques

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1985-01-01

    A procedure for using digital image processing techniques to measure the spatial correlation functions of composite heterogeneous materials is presented. Methods for eliminating undesirable biases and warping in digitized photographs are discussed. Fourier transform methods and array processor techniques for calculating the spatial correlation functions are treated. By introducing a minimal set of lattice-commensurate triangles, a method of sorting and storing the values of three-point correlation functions in a compact one-dimensional array is developed. Examples are presented at each stage of the analysis using synthetic photographs of cross sections of a model random material (the penetrable sphere model) for which the analytical form of the spatial correlations functions is known. Although results depend somewhat on magnification and on relative volume fraction, it is found that photographs digitized with 512 x 512 pixels generally have sufficiently good statistics for most practical purposes. To illustrate the use of the correlation functions, bounds on conductivity for the penetrable sphere model are calculated with a general numerical scheme developed for treating the singular three-dimensional integrals which must be evaluated

  19. Leucocyte classification for leukaemia detection using image processing techniques.

    Science.gov (United States)

    Putzu, Lorenzo; Caocci, Giovanni; Di Ruberto, Cecilia

    2014-11-01

    automatically via image processing techniques, and it represents a medical tool to avoid the numerous drawbacks associated with manual observation. This process could also be used for counting, as it provides excellent performance and allows for early diagnostic suspicion, which can then be confirmed by a haematologist through specialised techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Obtention of tumor volumes in PET images stacks using techniques of colored image segmentation

    International Nuclear Information System (INIS)

    Vieira, Jose W.; Lopes Filho, Ferdinand J.; Vieira, Igor F.

    2014-01-01

    This work demonstrated step by step how to segment color images of the chest of an adult in order to separate the tumor volume without significantly changing the values of the components R (Red), G (Green) and B (blue) of the colors of the pixels. For having information which allow to build color map you need to segment and classify the colors present at appropriate intervals in images. The used segmentation technique is to select a small rectangle with color samples in a given region and then erase with a specific color called 'rubber' the other regions of image. The tumor region was segmented into one of the images available and the procedure is displayed in tutorial format. All necessary computational tools have been implemented in DIP (Digital Image Processing), software developed by the authors. The results obtained, in addition to permitting the construction the colorful map of the distribution of the concentration of activity in PET images will also be useful in future work to enter tumors in voxel phantoms in order to perform dosimetric assessments

  1. Data-Driven Color Augmentation Techniques for Deep Skin Image Analysis

    OpenAIRE

    Galdran, Adrian; Alvarez-Gila, Aitor; Meyer, Maria Ines; Saratxaga, Cristina L.; Araújo, Teresa; Garrote, Estibaliz; Aresta, Guilherme; Costa, Pedro; Mendonça, A. M.; Campilho, Aurélio

    2017-01-01

    Dermoscopic skin images are often obtained with different imaging devices, under varying acquisition conditions. In this work, instead of attempting to perform intensity and color normalization, we propose to leverage computational color constancy techniques to build an artificial data augmentation technique suitable for this kind of images. Specifically, we apply the \\emph{shades of gray} color constancy technique to color-normalize the entire training set of images, while retaining the esti...

  2. Study of optical techniques for the Ames unitary wind tunnel: Digital image processing, part 6

    Science.gov (United States)

    Lee, George

    1993-01-01

    A survey of digital image processing techniques and processing systems for aerodynamic images has been conducted. These images covered many types of flows and were generated by many types of flow diagnostics. These include laser vapor screens, infrared cameras, laser holographic interferometry, Schlieren, and luminescent paints. Some general digital image processing systems, imaging networks, optical sensors, and image computing chips were briefly reviewed. Possible digital imaging network systems for the Ames Unitary Wind Tunnel were explored.

  3. Emerging Techniques in Brain Tumor Imaging: What Radiologists Need to Know

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minjae; Kim, Ho Sung [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of)

    2016-11-01

    Among the currently available brain tumor imaging, advanced MR imaging techniques, such as diffusion-weighted MR imaging and perfusion MR imaging, have been used for solving diagnostic challenges associated with conventional imaging and for monitoring the brain tumor treatment response. Further development of advanced MR imaging techniques and postprocessing methods may contribute to predicting the treatment response to a specific therapeutic regimen, particularly using multi-modality and multiparametric imaging. Over the next few years, new imaging techniques, such as amide proton transfer imaging, will be studied regarding their potential use in quantitative brain tumor imaging. In this review, the pathophysiologic considerations and clinical validations of these promising techniques are discussed in the context of brain tumor characterization and treatment response.

  4. Digital image analysis in breast pathology-from image processing techniques to artificial intelligence.

    Science.gov (United States)

    Robertson, Stephanie; Azizpour, Hossein; Smith, Kevin; Hartman, Johan

    2018-04-01

    Breast cancer is the most common malignant disease in women worldwide. In recent decades, earlier diagnosis and better adjuvant therapy have substantially improved patient outcome. Diagnosis by histopathology has proven to be instrumental to guide breast cancer treatment, but new challenges have emerged as our increasing understanding of cancer over the years has revealed its complex nature. As patient demand for personalized breast cancer therapy grows, we face an urgent need for more precise biomarker assessment and more accurate histopathologic breast cancer diagnosis to make better therapy decisions. The digitization of pathology data has opened the door to faster, more reproducible, and more precise diagnoses through computerized image analysis. Software to assist diagnostic breast pathology through image processing techniques have been around for years. But recent breakthroughs in artificial intelligence (AI) promise to fundamentally change the way we detect and treat breast cancer in the near future. Machine learning, a subfield of AI that applies statistical methods to learn from data, has seen an explosion of interest in recent years because of its ability to recognize patterns in data with less need for human instruction. One technique in particular, known as deep learning, has produced groundbreaking results in many important problems including image classification and speech recognition. In this review, we will cover the use of AI and deep learning in diagnostic breast pathology, and other recent developments in digital image analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Structural Image Analysis of the Brain in Neuropsychology Using Magnetic Resonance Imaging (MRI) Techniques.

    Science.gov (United States)

    Bigler, Erin D

    2015-09-01

    Magnetic resonance imaging (MRI) of the brain provides exceptional image quality for visualization and neuroanatomical classification of brain structure. A variety of image analysis techniques provide both qualitative as well as quantitative methods to relate brain structure with neuropsychological outcome and are reviewed herein. Of particular importance are more automated methods that permit analysis of a broad spectrum of anatomical measures including volume, thickness and shape. The challenge for neuropsychology is which metric to use, for which disorder and the timing of when image analysis methods are applied to assess brain structure and pathology. A basic overview is provided as to the anatomical and pathoanatomical relations of different MRI sequences in assessing normal and abnormal findings. Some interpretive guidelines are offered including factors related to similarity and symmetry of typical brain development along with size-normalcy features of brain anatomy related to function. The review concludes with a detailed example of various quantitative techniques applied to analyzing brain structure for neuropsychological outcome studies in traumatic brain injury.

  6. Infrared imaging - A validation technique for computational fluid dynamics codes used in STOVL applications

    Science.gov (United States)

    Hardman, R. R.; Mahan, J. R.; Smith, M. H.; Gelhausen, P. A.; Van Dalsem, W. R.

    1991-01-01

    The need for a validation technique for computational fluid dynamics (CFD) codes in STOVL applications has led to research efforts to apply infrared thermal imaging techniques to visualize gaseous flow fields. Specifically, a heated, free-jet test facility was constructed. The gaseous flow field of the jet exhaust was characterized using an infrared imaging technique in the 2 to 5.6 micron wavelength band as well as conventional pitot tube and thermocouple methods. These infrared images are compared to computer-generated images using the equations of radiative exchange based on the temperature distribution in the jet exhaust measured with the thermocouple traverses. Temperature and velocity measurement techniques, infrared imaging, and the computer model of the infrared imaging technique are presented and discussed. From the study, it is concluded that infrared imaging techniques coupled with the radiative exchange equations applied to CFD models are a valid method to qualitatively verify CFD codes used in STOVL applications.

  7. Enhancement of SAR images using fuzzy shrinkage technique in ...

    Indian Academy of Sciences (India)

    The synthetic aperture radar (SAR) images are mainly affected by speckle noise. Speckle degrades the features in the image and reduces the ability of a human observer to resolve fine detail, hence despeckling is very much required for SAR images. This paper presents speckle noise reduction in SAR images using a ...

  8. Percutaneous vertebroplasty with the rotational fluoroscopy imaging technique.

    Science.gov (United States)

    Cannavale, Alessandro; Salvatori, Filippo Maria; Wlderk, Andrea; Cirelli, Carlo; d'Adamo, Alessandro; Fanelli, Fabrizio

    2014-11-01

    To evaluate the feasibility of the rotational angiography unit (RAU) as a single technique to guide percutaneous vertebroplasty (PVP). Twenty-five consecutive patients (35 vertebral bodies, 20 lumbar and 15 thoracic) were treated using RA fluoroscopy. Using a state-of-the-art flat-panel angiographer (Artis zee, Siemens, Erlangen, Germany), rotational acquisitions were obtained in all patients for immediate post-procedure 2D/3D reconstructions. Pre- and postoperative back pain was assessed with the visual analog scale (VAS). Fluoroscopy time, patient radiation dose exposure, technical success, mean procedure time, mean number of rotational acquisitions and procedural complications were recorded. All features were compared with a historical cohort of patients (N = 25) who underwent PVP under CT and mobile C-arm fluoroscopy guidance. In all cases, safe and accurate control of the needle insertion and bone-cement injection was successfully obtained with high-quality fluoroscopy images. One cement leakage was detected in the RAU group, and two leakages were detected in the CT and C-arm fluoroscopy group. Technical features were significantly different between the two groups (RAU vs. CT): mean procedure time: 38.2 min vs. 60.2 min (p = 0.02); median fluoroscopy time: 14.58 and 4.58 min (p = 0.02); median number of rotational acquisitions: 5 vs. 10 (p = 0.02); mean patient dose: 6 ± 1.3 mSv vs. 23 ± 1.3 mSv (p = 0.02). There were minor complications (pain, small hematoma) in two patients (8%) in the study group and three cases (12%) in the control group. RAU guidance is an effective and safe technique for performing PVP because it reduces the procedural time and radiation exposure.

  9. Percutaneous vertebroplasty with the rotational fluoroscopy imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Cannavale, Alessandro; Salvatori, Filippo Maria; Wlderk, Andrea; Cirelli, Carlo; D' Adamo, Alessandro; Fanelli, Fabrizio [University of Rome, Vascular and Interventional Unit, Department of Radiological Sciences, Rome (Italy)

    2014-11-15

    To evaluate the feasibility of the rotational angiography unit (RAU) as a single technique to guide percutaneous vertebroplasty (PVP). Twenty-five consecutive patients (35 vertebral bodies, 20 lumbar and 15 thoracic) were treated using RA fluoroscopy. Using a state-of-the-art flat-panel angiographer (Artis zee, Siemens, Erlangen, Germany), rotational acquisitions were obtained in all patients for immediate post-procedure 2D/3D reconstructions. Pre- and postoperative back pain was assessed with the visual analog scale (VAS). Fluoroscopy time, patient radiation dose exposure, technical success, mean procedure time, mean number of rotational acquisitions and procedural complications were recorded. All features were compared with a historical cohort of patients (N = 25) who underwent PVP under CT and mobile C-arm fluoroscopy guidance. In all cases, safe and accurate control of the needle insertion and bone-cement injection was successfully obtained with high-quality fluoroscopy images. One cement leakage was detected in the RAU group, and two leakages were detected in the CT and C-arm fluoroscopy group. Technical features were significantly different between the two groups (RAU vs. CT): mean procedure time: 38.2 min vs. 60.2 min (p = 0.02); median fluoroscopy time: 14.58 and 4.58 min (p = 0.02); median number of rotational acquisitions: 5 vs. 10 (p = 0.02); mean patient dose: 6 ± 1.3 mSv vs. 23 ± 1.3 mSv (p = 0.02). There were minor complications (pain, small hematoma) in two patients (8%) in the study group and three cases (12%) in the control group. RAU guidance is an effective and safe technique for performing PVP because it reduces the procedural time and radiation exposure. (orig.)

  10. Ancestry of indirect techniques for X-ray imaging

    International Nuclear Information System (INIS)

    Mertz, L.

    1989-01-01

    Historical citations concerning the origins of coded-aperture imaging are corrected. Another scheme is presented for synthetic indirect imaging to overcome certain shortcomings of simple coded apertures. Pairs of Fresnel zone patterns are used to create moire patterns that can be Fourier transformed for image reconstruction. It is also conjectured that image reconstructions that are constrained to be nonnegative should overcome certain complaints concerning indirect imaging. 20 refs

  11. Quality Improvement of Liver Ultrasound Images Using Fuzzy Techniques.

    Science.gov (United States)

    Bayani, Azadeh; Langarizadeh, Mostafa; Radmard, Amir Reza; Nejad, Ahmadreza Farzaneh

    2016-12-01

    Liver ultrasound images are so common and are applied so often to diagnose diffuse liver diseases like fatty liver. However, the low quality of such images makes it difficult to analyze them and diagnose diseases. The purpose of this study, therefore, is to improve the contrast and quality of liver ultrasound images. In this study, a number of image contrast enhancement algorithms which are based on fuzzy logic were applied to liver ultrasound images - in which the view of kidney is observable - using Matlab2013b to improve the image contrast and quality which has a fuzzy definition; just like image contrast improvement algorithms using a fuzzy intensification operator, contrast improvement algorithms applying fuzzy image histogram hyperbolization, and contrast improvement algorithms by fuzzy IF-THEN rules. With the measurement of Mean Squared Error and Peak Signal to Noise Ratio obtained from different images, fuzzy methods provided better results, and their implementation - compared with histogram equalization method - led both to the improvement of contrast and visual quality of images and to the improvement of liver segmentation algorithms results in images. Comparison of the four algorithms revealed the power of fuzzy logic in improving image contrast compared with traditional image processing algorithms. Moreover, contrast improvement algorithm based on a fuzzy intensification operator was selected as the strongest algorithm considering the measured indicators. This method can also be used in future studies on other ultrasound images for quality improvement and other image processing and analysis applications.

  12. USE OF IMAGE ENHANCEMENT TECHNIQUES FOR IMPROVING REAL TIME FACE RECOGNITION EFFICIENCY ON WEARABLE GADGETS

    Directory of Open Access Journals (Sweden)

    MUHAMMAD EHSAN RANA

    2017-01-01

    Full Text Available The objective of this research is to study the effects of image enhancement techniques on face recognition performance of wearable gadgets with an emphasis on recognition rate.In this research, a number of image enhancement techniques are selected that include brightness normalization, contrast normalization, sharpening, smoothing, and various combinations of these. Subsequently test images are obtained from AT&T database and Yale Face Database B to investigate the effect of these image enhancement techniques under various conditions such as change of illumination and face orientation and expression.The evaluation of data, collected during this research, revealed that the effect of image pre-processing techniques on face recognition highly depends on the illumination condition under which these images are taken. It is revealed that the benefit of applying image enhancement techniques on face images is best seen when there is high variation of illumination among images. Results also indicate that highest recognition rate is achieved when images are taken under low light condition and image contrast is enhanced using histogram equalization technique and then image noise is reduced using median smoothing filter. Additionally combination of contrast normalization and mean smoothing filter shows good result in all scenarios. Results obtained from test cases illustrate up to 75% improvement in face recognition rate when image enhancement is applied to images in given scenarios.

  13. An efficient simultaneous reconstruction technique for tomographic particle image velocimetry

    Science.gov (United States)

    Atkinson, Callum; Soria, Julio

    2009-10-01

    To date, Tomo-PIV has involved the use of the multiplicative algebraic reconstruction technique (MART), where the intensity of each 3D voxel is iteratively corrected to satisfy one recorded projection, or pixel intensity, at a time. This results in reconstruction times of multiple hours for each velocity field and requires considerable computer memory in order to store the associated weighting coefficients and intensity values for each point in the volume. In this paper, a rapid and less memory intensive reconstruction algorithm is presented based on a multiplicative line-of-sight (MLOS) estimation that determines possible particle locations in the volume, followed by simultaneous iterative correction. Reconstructions of simulated images are presented for two simultaneous algorithms (SART and SMART) as well as the now standard MART algorithm, which indicate that the same accuracy as MART can be achieved 5.5 times faster or 77 times faster with 15 times less memory if the processing and storage of the weighting matrix is considered. Application of MLOS-SMART and MART to a turbulent boundary layer at Re θ = 2200 using a 4 camera Tomo-PIV system with a volume of 1,000 × 1,000 × 160 voxels is discussed. Results indicate improvements in reconstruction speed of 15 times that of MART with precalculated weighting matrix, or 65 times if calculation of the weighting matrix is considered. Furthermore the memory needed to store a large weighting matrix and volume intensity is reduced by almost 40 times in this case.

  14. Role of Imaging Techniques in Percutaneous Treatment of Mitral Regurgitation.

    Science.gov (United States)

    Li, Chi-Hion; Arzamendi, Dabit; Carreras, Francesc

    2016-04-01

    Mitral regurgitation is the most prevalent valvular heart disease in the United States and the second most prevalent in Europe. Patients with severe mitral regurgitation have a poor prognosis with medical therapy once they become symptomatic or develop signs of significant cardiac dysfunction. However, as many as half of these patients are inoperable because of advanced age, ventricular dysfunction, or other comorbidities. Studies have shown that surgery increases survival in patients with organic mitral regurgitation due to valve prolapse but has no clinical benefit in those with functional mitral regurgitation. In this scenario, percutaneous repair for mitral regurgitation in native valves provides alternative management of valvular heart disease in patients at high surgical risk. Percutaneous repair for mitral regurgitation is a growing field that relies heavily on imaging techniques to diagnose functional anatomy and guide repair procedures. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  15. CT and MRI techniques for imaging around orthopedic hardware

    International Nuclear Information System (INIS)

    Do, Thuy Duong; Skornitzke, Stephan; Weber, Marc-Andre; Sutter, Reto

    2018-01-01

    Orthopedic hardware impairs image quality in cross-sectional imaging. With an increasing number of orthopedic implants in an aging population, the need to mitigate metal artifacts in computed tomography and magnetic resonance imaging is becoming increasingly relevant. This review provides an overview of the major artifacts in CT and MRI and state-of-the-art solutions to improve image quality. All steps of image acquisition from device selection, scan preparations and parameters to image post-processing influence the magnitude of metal artifacts. Technological advances like dual-energy CT with the possibility of virtual monochromatic imaging (VMI) and new materials offer opportunities to further reduce artifacts in CT and MRI. Dedicated metal artifact reduction sequences contain algorithms to reduce artifacts and improve imaging of surrounding tissue and are essential tools in orthopedic imaging to detect postoperative complications in early stages.

  16. A Novel Feature Extraction Technique Using Binarization of Bit Planes for Content Based Image Classification

    Directory of Open Access Journals (Sweden)

    Sudeep Thepade

    2014-01-01

    Full Text Available A number of techniques have been proposed earlier for feature extraction using image binarization. Efficiency of the techniques was dependent on proper threshold selection for the binarization method. In this paper, a new feature extraction technique using image binarization has been proposed. The technique has binarized the significant bit planes of an image by selecting local thresholds. The proposed algorithm has been tested on a public dataset and has been compared with existing widely used techniques using binarization for extraction of features. It has been inferred that the proposed method has outclassed all the existing techniques and has shown consistent classification performance.

  17. AN IMAGE-BASED TECHNIQUE FOR 3D BUILDING RECONSTRUCTION USING MULTI-VIEW UAV IMAGES

    Directory of Open Access Journals (Sweden)

    F. Alidoost

    2015-12-01

    Full Text Available Nowadays, with the development of the urban areas, the automatic reconstruction of the buildings, as an important objects of the city complex structures, became a challenging topic in computer vision and photogrammetric researches. In this paper, the capability of multi-view Unmanned Aerial Vehicles (UAVs images is examined to provide a 3D model of complex building façades using an efficient image-based modelling workflow. The main steps of this work include: pose estimation, point cloud generation, and 3D modelling. After improving the initial values of interior and exterior parameters at first step, an efficient image matching technique such as Semi Global Matching (SGM is applied on UAV images and a dense point cloud is generated. Then, a mesh model of points is calculated using Delaunay 2.5D triangulation and refined to obtain an accurate model of building. Finally, a texture is assigned to mesh in order to create a realistic 3D model. The resulting model has provided enough details of building based on visual assessment.

  18. Tumor functional and molecular imaging utilizing ultrasound and ultrasound-mediated optical techniques.

    Science.gov (United States)

    Yuan, Baohong; Rychak, Joshua

    2013-02-01

    Tumor functional and molecular imaging has significantly contributed to cancer preclinical research and clinical applications. Among typical imaging modalities, ultrasonic and optical techniques are two commonly used methods; both share several common features such as cost efficiency, absence of ionizing radiation, relatively inexpensive contrast agents, and comparable maximum-imaging depth. Ultrasonic and optical techniques are also complementary in imaging resolution, molecular sensitivity, and imaging space (vascular and extravascular). The marriage between ultrasonic and optical techniques takes advantages of both techniques. This review introduces tumor functional and molecular imaging using microbubble-based ultrasound and ultrasound-mediated optical imaging techniques. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  19. Multimodality Image Fusion-Guided Procedures: Technique, Accuracy, and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Abi-Jaoudeh, Nadine, E-mail: naj@mail.nih.gov [National Institutes of Health, Radiology and Imaging Sciences (United States); Kruecker, Jochen, E-mail: jochen.kruecker@philips.com [Philips Research North America (United States); Kadoury, Samuel, E-mail: samuel.kadoury@polymtl.ca [Ecole Polytechnique de Montreal, Department of Computer and Software Engineering, Institute of Biomedical Engineering (Canada); Kobeiter, Hicham, E-mail: hicham.kobeiter@gmail.com [CHU Henri Mondor, UPEC, Departments of Radiology and d' imagrie medicale (France); Venkatesan, Aradhana M., E-mail: VenkatesanA@cc.nih.gov; Levy, Elliot, E-mail: levyeb@cc.nih.gov; Wood, Bradford J., E-mail: bwood@cc.nih.gov [National Institutes of Health, Radiology and Imaging Sciences (United States)

    2012-10-15

    Personalized therapies play an increasingly critical role in cancer care: Image guidance with multimodality image fusion facilitates the targeting of specific tissue for tissue characterization and plays a role in drug discovery and optimization of tailored therapies. Positron-emission tomography (PET), magnetic resonance imaging (MRI), and contrast-enhanced computed tomography (CT) may offer additional information not otherwise available to the operator during minimally invasive image-guided procedures, such as biopsy and ablation. With use of multimodality image fusion for image-guided interventions, navigation with advanced modalities does not require the physical presence of the PET, MRI, or CT imaging system. Several commercially available methods of image-fusion and device navigation are reviewed along with an explanation of common tracking hardware and software. An overview of current clinical applications for multimodality navigation is provided.

  20. CT urethrography. New imaging technique of the urethra

    International Nuclear Information System (INIS)

    Takeyama, Nobuyuki; Munechika, Hirotsugu

    2005-01-01

    The purpose of the study is to assess the usefulness of CT urethrography for evaluation of the posterior urethra and surrounding structures. The CT images were performed with 4 channel multidetector row CT unit. Twenty-six cases (12 cases of CT urethrography and 14 cases of conventional urethrography) were included in this study. 3D-volume rendering (VR) images and VR-multiplaner reconstruction (MPR) sagittal images were compared with conventional retrograde urethrography (RUG) images to evaluate the following anatomical structures; the inferior wall of bladder, the neck of bladder, the posterior urethra, and the prostate. Two radiologists undertook a task of evaluation of the images. There was no significant difference in image quality between RUG and 3D-VR. However, VR-MPR sagittal images were significantly better than RUG or 3D-VR images in any anatomical structures set up beforehand for evaluation. CT urerthrography was useful for evaluation of the posterior urethra and surrounding structures. (author)

  1. A CLASSICAL REVIEW ON ADVANCED DIGITAL IMAGE WATERMARKING TECHNIQUES

    OpenAIRE

    BAISA L. GUNJAL

    2018-01-01

    The world has become a global village in digital era due to advances in internet and communication technology. Presently, creation, copy and transmission of image data via internet and mobile phone are very common practices. The access, sharing, replication and manipulation of medical images have become daily needs. Image data distributed can be copied repeatedly without errors putting the rights of owners at risk. Even though encrypted for distribution, images can be unprotected after decryp...

  2. Comparing techniques for vegetation classification using multi- and hyperspectral images and ancillary environmental data

    NARCIS (Netherlands)

    Sluiter, R; Pebesma, E.J.

    2010-01-01

    This paper evaluates the predictive power of innovative and more conventional statistical classification techniques. We use Landsat 7 Enhanced Thematic Mapper Plus (ETMþ), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and airborne imaging spectrometer (HyMap) images

  3. An efficient similarity measure technique for medical image registration

    Indian Academy of Sciences (India)

    are obtained from the reference image by cropping the defective area using Adobe Photoshop. 7.0.1 software. In figure 4, row 1 shows the registration results for the image having the subacute stroke disease. The template image shows the particular affected region. In this experiment, the illu- mination (local distortion) effect ...

  4. A comparison of signal processing techniques for Intrinsic Optical Signal imaging in mice.

    Science.gov (United States)

    Turley, Jordan A; Nilsson, Michael; Walker, Frederick Rohan; Johnson, Sarah J

    2015-01-01

    Intrinsic Optical Signal imaging is a technique which allows the visualisation and mapping of activity related changes within the brain with excellent spatial and temporal resolution. We analysed a variety of signal and image processing techniques applied to real mouse imaging data. The results were compared in an attempt to overcome the unique issues faced when performing the technique on mice and improve the understanding of post processing options available.

  5. Imaging techniques in digital forensic investigation: a study using neural networks

    Science.gov (United States)

    Williams, Godfried

    2006-09-01

    Imaging techniques have been applied to a number of applications, such as translation and classification problems in medicine and defence. This paper examines the application of imaging techniques in digital forensics investigation using neural networks. A review of applications of digital image processing is presented, whiles a Pedagogical analysis of computer forensics is also highlighted. A data set describing selected images in different forms are used in the simulation and experimentation.

  6. Ultrasonic off-normal imaging techniques for under sodium viewing

    International Nuclear Information System (INIS)

    Michaels, T.E.; Horn, J.E.

    1979-01-01

    Advanced imaging methods have been evaluated for the purpose of constructing images of objects from ultrasonic data. Feasibility of imaging surfaces which are off-normal to the sound beam has been established. Laboratory results are presented which show a complete image of a typical core component. Using the previous system developed for under sodium viewing (USV), only normal surfaces of this object could be imaged. Using advanced methods, surfaces up to 60 degrees off-normal have been imaged. Details of equipment and procedures used for this image construction are described. Additional work on high temperature transducers, electronics, and signal analysis is required in order to adapt the off-normal viewing process described here to an eventual USV application

  7. Radar Image Enhancement, Feature Extraction and Motion Compensation Using Joint Time-Frequency Techniques

    National Research Council Canada - National Science Library

    Ling, Hao

    2001-01-01

    This report summarizes the scientific progress on the research grant "Radar image Enhancement, Feature Extraction, and Motion Compensation Using Joint Time-Frequency Techniques" during the period 15...

  8. Radar Image Enhancement, Feature Extraction and Motion Compensation Using Joint Time-Frequency Techniques

    National Research Council Canada - National Science Library

    Ling, Hao

    1999-01-01

    This Report summarizes the scientific progress on the research grant "Radar Image Enhancement, Feature Extraction, and Motion Compensation Using Joint Time-Frequency Techniques" during the period 15...

  9. Optimization of coronary optical coherence tomography imaging using the attenuation-compensated technique: a validation study.

    NARCIS (Netherlands)

    Teo, Jing Chun; Foin, Nicolas; Otsuka, Fumiyuki; Bulluck, Heerajnarain; Fam, Jiang Ming; Wong, Philip; Low, Fatt Hoe; Leo, Hwa Liang; Mari, Jean-Martial; Joner, Michael; Girard, Michael J A; Virmani, Renu; Bezerra, HG.; Costa, MA.; Guagliumi, G.; Rollins, AM.; Simon, D.; Gutiérrez-Chico, JL.; Alegría-Barrero, E.; Teijeiro-Mestre, R.; Chan, PH.; Tsujioka, H.; de Silva, R.; Otsuka, F.; Joner, M.; Prati, F.; Virmani, R.; Narula, J.; Members, WC.; Levine, GN.; Bates, ER.; Blankenship, JC.; Bailey, SR.; Bittl, JA.; Prati, F.; Guagliumi, G.; Mintz, G.S.; Costa, Marco; Regar, E.; Akasaka, T.; Roleder, T.; Jąkała, J.; Kałuża, GL.; Partyka, Ł.; Proniewska, K.; Pociask, E.; Girard, MJA.; Strouthidis, NG.; Ethier, CR.; Mari, JM.; Mari, JM.; Strouthidis, NG.; Park, SC.; Girard, MJA.; van der Lee, R.; Foin, N.; Otsuka, F.; Wong, P.K.; Mari, J-M.; Joner, M.; Nakano, M.; Vorpahl, M.; Otsuka, F.; Taniwaki, M.; Yazdani, SK.; Finn, AV.; Nakano, M.; Yahagi, K.; Yamamoto, H.; Taniwaki, M.; Otsuka, F.; Ladich, ER.; Girard, MJ.; Ang, M.; Chung, CW.; Farook, M.; Strouthidis, N.; Mehta, JS.; Foin, N.; Mari, JM.; Nijjer, S.; Sen, S.; Petraco, R.; Ghione, M.; Liu, X.; Kang, JU.; Virmani, R.; Kolodgie, F.D.; Burke, AP.; Farb, A.; Schwartz, S.M.; Yahagi, K.; Kolodgie, F.D.; Otsuka, F.; Finn, AV.; Davis, HR.; Joner, M.; Kume, T.; Akasaka, T.; Kawamoto, T.; Watanabe, N.; Toyota, E.; Neishi, Y.; Rieber, J.; Meissner, O.; Babaryka, G.; Reim, S.; Oswald, M.E.; Koenig, A.S.; Tearney, G. J.; Regar, E.; Akasaka, T.; Adriaenssens, T.; Barlis, P.; Bezerra, HG.; Yabushita, H.; Bouma, BE.; Houser, S. L.; Aretz, HT.; Jang, I-K.; Schlendorf, KH.; Guo, J.; Sun, L.; Chen, Y.D.; Tian, F.; Liu, HB.; Chen, L.; Kawasaki, M.; Bouma, BE.; Bressner, J. E.; Houser, S. L.; Nadkarni, S. K.; MacNeill, BD.; Jansen, CHP.; Onthank, DC.; Cuello, F.; Botnar, RM.; Wiethoff, AJ.; Warley, A.; von Birgelen, C.; Hartmann, A. M.; Kubo, T.; Akasaka, T.; Shite, J.; Suzuki, T.; Uemura, S.; Yu, B.; Habara, M.; Nasu, K.; Terashima, M.; Kaneda, H.; Yokota, D.; Ko, E.; Virmani, R.; Burke, AP.; Kolodgie, F.D.; Farb, A.; Takarada, S.; Imanishi, T.; Kubo, T.; Tanimoto, T.; Kitabata, H.; Nakamura, N.; Hattori, K.; Ozaki, Y.; Ismail, TF.; Okumura, M.; Naruse, H.; Kan, S.; Nishio, R.; Shinke, T.; Otake, H.; Nakagawa, M.; Nagoshi, R.; Inoue, T.; Sinclair, H.D.; Bourantas, C.; Bagnall, A.; Mintz, G.S.; Kunadian, V.; Tearney, G. J.; Yabushita, H.; Houser, S. L.; Aretz, HT.; Jang, I-K.; Schlendorf, KH.; van Soest, G.; Goderie, T.; Regar, E.; Koljenović, S.; Leenders, GL. van; Gonzalo, N.; Xu, C.; Schmitt, JM.; Carlier, SG.; Virmani, R.; van der Meer, FJ; Faber, D.J.; Sassoon, DMB.; Aalders, M.C.; Pasterkamp, G.; Leeuwen, TG. van; Schmitt, JM.; Knuttel, A.; Yadlowsky, M.; Eckhaus, MA.; Karamata, B.; Laubscher, M.; Leutenegger, M.; Bourquin, S.; Lasser, T.; Lambelet, P.; Vermeer, K.A.; Mo, J.; Weda, J.J.A.; Lemij, H.G.; Boer, JF. de

    2016-01-01

    PURPOSE To optimize conventional coronary optical coherence tomography (OCT) images using the attenuation-compensated technique to improve identification of plaques and the external elastic lamina (EEL) contour. METHOD The attenuation-compensated technique was optimized via manipulating contrast

  10. Three-dimensional radar imaging techniques and systems for near-field applications

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, David M.; Hall, Thomas E.; McMakin, Douglas L.; Jones, Anthony M.; Tedeschi, Jonathan R.

    2016-05-12

    The Pacific Northwest National Laboratory has developed three-dimensional holographic (synthetic aperture) radar imaging techniques and systems for a wide variety of near-field applications. These applications include radar cross-section (RCS) imaging, personnel screening, standoff concealed weapon detection, concealed threat detection, through-barrier imaging, ground penetrating radar (GPR), and non-destructive evaluation (NDE). Sequentially-switched linear arrays are used for many of these systems to enable high-speed data acquisition and 3-D imaging. In this paper, the techniques and systems will be described along with imaging results that demonstrate the utility of near-field 3-D radar imaging for these compelling applications.

  11. Facial nerve image enhancement from CBCT using supervised learning technique.

    Science.gov (United States)

    Ping Lu; Barazzetti, Livia; Chandran, Vimal; Gavaghan, Kate; Weber, Stefan; Gerber, Nicolas; Reyes, Mauricio

    2015-08-01

    Facial nerve segmentation plays an important role in surgical planning of cochlear implantation. Clinically available CBCT images are used for surgical planning. However, its relatively low resolution renders the identification of the facial nerve difficult. In this work, we present a supervised learning approach to enhance facial nerve image information from CBCT. A supervised learning approach based on multi-output random forest was employed to learn the mapping between CBCT and micro-CT images. Evaluation was performed qualitatively and quantitatively by using the predicted image as input for a previously published dedicated facial nerve segmentation, and cochlear implantation surgical planning software, OtoPlan. Results show the potential of the proposed approach to improve facial nerve image quality as imaged by CBCT and to leverage its segmentation using OtoPlan.

  12. Aliasless fresnel transform image reconstruction in phase scrambling fourier transform technique by data interpolation

    International Nuclear Information System (INIS)

    Yamada, Yoshifumi; Liu, Na; Ito, Satoshi

    2006-01-01

    The signal in the Fresnel transform technique corresponds to a blurred one of the spin density image. Because the amplitudes of adjacent sampled signals have a high interrelation, the signal amplitude at a point between sampled points can be estimated with a high degree of accuracy even if the sampling is so coarse as to generate aliasing in the reconstructed images. In this report, we describe a new aliasless image reconstruction technique in the phase scrambling Fourier transform (PSFT) imaging technique in which the PSFT signals are converted to Fresnel transform signals by multiplying them by a quadratic phase term and are then interpolated using polynomial expressions to generate fully encoded signals. Numerical simulation using MR images showed that almost completely aliasless images are reconstructed by this technique. Experiments using ultra-low-field PSFT MRI were conducted, and aliasless images were reconstructed from coarsely sampled PSFT signals. (author)

  13. Imaging technique for detection of leaf surface contaminations with fission fragments

    International Nuclear Information System (INIS)

    Furuta, Etsuko

    2011-01-01

    Fission fragments by the Fukushima Daiichi catastrophe were scattered over a large area. Between Tokyo and Fukushima, leaves were gathered up from March to June and measured their radioactivities by HPGe. Radionuclides of 129m Tc, 131 I, 134 Cs and 137 Cs were rightly detected. Also the leaf surface contaminations were shown as images by imaging technique which detected beta- and gamma-rays exposure. The clear images were gotten within 24 h exposure though a normal leaf image needs at least one week exposure in a shield box. The total PSL values of leaves depend on their activities of sampling points, so the imaging technique is able to use for detection of the spread of fission fragments and the relative concentration. Also the rain effect to leaves could be shown by imaging technique when leaves were washed in running water. The imaging technique is easy and useful for the nuclear catastrophe. (author)

  14. Content based image retrieval using local binary pattern operator and data mining techniques.

    Science.gov (United States)

    Vatamanu, Oana Astrid; Frandeş, Mirela; Lungeanu, Diana; Mihalaş, Gheorghe-Ioan

    2015-01-01

    Content based image retrieval (CBIR) concerns the retrieval of similar images from image databases, using feature vectors extracted from images. These feature vectors globally define the visual content present in an image, defined by e.g., texture, colour, shape, and spatial relations between vectors. Herein, we propose the definition of feature vectors using the Local Binary Pattern (LBP) operator. A study was performed in order to determine the optimum LBP variant for the general definition of image feature vectors. The chosen LBP variant is then subsequently used to build an ultrasound image database, and a database with images obtained from Wireless Capsule Endoscopy. The image indexing process is optimized using data clustering techniques for images belonging to the same class. Finally, the proposed indexing method is compared to the classical indexing technique, which is nowadays widely used.

  15. Scintigraphic image contrast-enhancement techniques: global and local area histogram equalization.

    Science.gov (United States)

    Verdenet, J; Cardot, J C; Baud, M; Chervet, H; Duvernoy, J; Bidet, R

    1981-01-01

    This article develops two contrast-modification techniques for the display of scintigraphic images. Based on histogram-modification techniques, histogram equalization, where each level of gray is used to the same extent, gives maximum entropy. The first technique uses the application of histogram equalization in the whole image. To eliminate contrast attenuation small but important portion of the gray scale histogram, local area histogram equalization has been applied to images with differences in intensity. Both techniques were tested using a phantom with known characteristics. The global equalization technique is more suitable to bone scintigraphies, and some well-chosen boundaries improved the difference between two comparable areas. For liver scintigraphies, where intensity is quite equal in every pixel, a local area equalization was chosen that allowed detection of heterogeneous structures. The images resulting from histogram-equalization techniques improve the readability of data, but are often far from usual images and necessitate an apprenticeship for the physician.

  16. Segmentation techniques for extracting humans from thermal images

    CSIR Research Space (South Africa)

    Dickens, JS

    2011-11-01

    Full Text Available will be classified. Various methods for segmenting people from thermal images will be reviewed and compared. Image thresholding takes in a multi-valued input image and outputs a binary image where one of the states represents fore- ground objects and the other... that the between class variance, 2b , is: 2b = ( T!(k) (k)) 2 !(k) (1 !(k)) (6) Otsu?s method selects the optimal threshold Topt in order to maximise the between class variance. The optimal threshold is the value of k that maximises Equation 6, ie. Topt...

  17. Applications of digital scintillation imaging technique in medical and nuclear research

    International Nuclear Information System (INIS)

    Sinha, Amar

    2001-01-01

    This paper reviews various applications of digital scintillation imaging technique particularly those related to medical and nuclear research. Use of various scintillators, their advantages and limitations for different applications will be discussed in this paper. Work being carried out at BARC in the field of digital medical imaging, x-ray diffraction imaging using CCD detectors, digital neutron imaging, nuclear particle imaging will also be emphasised in this paper. (author)

  18. Radiation protection in newer medical imaging techniques: PET/CT

    International Nuclear Information System (INIS)

    2008-01-01

    A major part of patient exposure now arises from practices that barely existed two decades ago, and the technological basis for their successful dissemination only began to flourish in the last decade or so. Hybrid imaging systems, such as the combination of computed tomography (CT) and positron emission tomography (PET), are an example of a technique that has only been introduced in the last decade. PET/CT has established a valuable place for itself in medical research and diagnosis. However, it is an application that can result in high patient and staff doses. For practitioners and regulators, it is evident that innovation has been driven both by the imaging industry and by an increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practices lag (inevitably) behind the industrial and clinical innovations. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill the growing vacuum, by bringing up to date and timely advice from experienced practitioners to bear on the problems involved. The advice in this report has been developed within the IAEA's statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for the worldwide application of these standards. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) were issued by the IAEA and co-sponsored by organizations including the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organisation (ILO), the OECD Nuclear Energy Agency (OECD/NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO), and require the radiation protection of patients undergoing medical exposures through justification of the procedures involved and through

  19. A study of correlation technique on pyramid processed images

    Indian Academy of Sciences (India)

    The pyramid algorithm is potentially a powerful tool for advanced television image processing and for pattern recognition. An attempt is made to design and develop both hardware and software for a system which performs decomposition and reconstruction of digitized images by implementing the Burt pyramid algorithm.

  20. A study of correlation technique on pyramid processed images

    Indian Academy of Sciences (India)

    processed levels. In this paper results are presented in terms of RMS error between original and expanded images. Only still images are considered, and the hardware is ... the signal information in a particular band is computed using a small subregion of the ... A straightforward approach that uses standard, digital,.

  1. REVIEW ON LUNG CANCER DETECTION USING IMAGE PROCESSING TECHNIQUE

    OpenAIRE

    Anam Quadri; Rashida Shujaee; Nishat Khan

    2016-01-01

    This paper presents a review on the lung cancer detection method using image processing. In recent years the image processing mechanisms are used widely in several medical areas for improving earlier detection and treatment stages.Also the different procedures and design methodologies for the same have also been discussed

  2. Unsupervised Neural Techniques Applied to MR Brain Image Segmentation

    Directory of Open Access Journals (Sweden)

    A. Ortiz

    2012-01-01

    Full Text Available The primary goal of brain image segmentation is to partition a given brain image into different regions representing anatomical structures. Magnetic resonance image (MRI segmentation is especially interesting, since accurate segmentation in white matter, grey matter and cerebrospinal fluid provides a way to identify many brain disorders such as dementia, schizophrenia or Alzheimer’s disease (AD. Then, image segmentation results in a very interesting tool for neuroanatomical analyses. In this paper we show three alternatives to MR brain image segmentation algorithms, with the Self-Organizing Map (SOM as the core of the algorithms. The procedures devised do not use any a priori knowledge about voxel class assignment, and results in fully-unsupervised methods for MRI segmentation, making it possible to automatically discover different tissue classes. Our algorithm has been tested using the images from the Internet Brain Image Repository (IBSR outperforming existing methods, providing values for the average overlap metric of 0.7 for the white and grey matter and 0.45 for the cerebrospinal fluid. Furthermore, it also provides good results for high-resolution MR images provided by the Nuclear Medicine Service of the “Virgen de las Nieves” Hospital (Granada, Spain.

  3. A technique for the deidentification of structural brain MR images

    DEFF Research Database (Denmark)

    Bischoff-Grethe, Amanda; Ozyurt, I Burak; Busa, Evelina

    2007-01-01

    Due to the increasing need for subject privacy, the ability to deidentify structural MR images so that they do not provide full facial detail is desirable. A program was developed that uses models of nonbrain structures for removing potentially identifying facial features. When a novel image...

  4. A novel image inpainting technique based on median diffusion

    Indian Academy of Sciences (India)

    Computer Graphics Processing, 417–424. Bertalmio M, Bertozzi A L and Sapiro G 2001 Navier–Stokes, fluid dynamics and image and video inpainting. In: IEEE CVPR. Bertalmio M. Vese L, Sapiro G and Osher S 2003 Simultaneous strucure and texture image inpainting. In: UCLA CAM report 02–47. Bianjing Bai, Zhenjiang ...

  5. High Resolution Radar Imaging using Coherent MultiBand Processing Techniques

    NARCIS (Netherlands)

    Dorp, Ph. van; Ebeling, R.P.; Huizing, A.G.

    2010-01-01

    High resolution radar imaging techniques can be used in ballistic missile defence systems to determine the type of ballistic missile during the boost phase (threat typing) and to discriminate different parts of a ballistic missile after the boost phase. The applied radar imaging technique is 2D

  6. A preliminary investigation of communication techniques for local and remote access to image databases

    Science.gov (United States)

    Ma, Mathias; Danielson, Ronald L.; Likens, William C.

    1988-01-01

    A software technique which allows users to examine images remotely while minimizing transmission time, is discussed. The technique provides a browsing capability, making it possible to roam over larger images, to zoom to various resolution levels, and to specify subregions of interest in the image to display at full resolution. The software permits analysts to remotely submit images for processing and to review the processing result. The capabilities of the technique under varying conditions and the speed at which imagery can be displayed over direct connect serial lines are discussed and examples of the imagery at various levels of resolution are presented.

  7. Improvements in image quality with pseudo-parallel imaging in the phase-scrambling fourier transform technique

    International Nuclear Information System (INIS)

    Ito, Satoshi; Kawawa, Yasuhiro; Yamada, Yoshifumi

    2010-01-01

    The signal obtained in the phase-scrambling Fourier transform (PSFT) imaging technique can be transformed to the signal described by the Fresnel transform of the objects, in which the amplitude of the PSFT presents some kind of blurred image of the objects. Therefore, the signal can be considered to exist in the object domain as well as the Fourier domain of the object. This notable feature makes it possible to assign weights to the reconstructed images by applying a weighting function to the PSFT signal after data acquisition, and as a result, pseudo-parallel image reconstruction using these aliased image data with different weights on the images is feasible. In this study, the improvements in image quality with such pseudo-parallel imaging were examined and demonstrated. The weighting function of the PSFT signal that provides a given weight on the image is estimated using the obtained image data and is iteratively updated after sensitivity encoding (SENSE)-based image reconstruction. Simulation studies showed that reconstruction errors were dramatically reduced and that the spatial resolution was also improved in almost all image spaces. The proposed method was applied to signals synthesized from MR image data with phase variations to verify its effectiveness. It was found that the image quality was improved and that images almost entirely free of aliasing artifacts could be obtained. (author)

  8. A graphical simulator for teaching basic and advanced MR imaging techniques

    DEFF Research Database (Denmark)

    Hanson, Lars G

    2007-01-01

    Teaching of magnetic resonance (MR) imaging techniques typically involves considerable handwaving, literally, to explain concepts such as resonance, rotating frames, dephasing, refocusing, sequences, and imaging. A proper understanding of MR contrast and imaging techniques is crucial for radiolog......Teaching of magnetic resonance (MR) imaging techniques typically involves considerable handwaving, literally, to explain concepts such as resonance, rotating frames, dephasing, refocusing, sequences, and imaging. A proper understanding of MR contrast and imaging techniques is crucial...... for radiologists, radiographers, and technical staff alike, but it is notoriously challenging to explain spin dynamics by using traditional teaching tools. The author developed a freely available graphical simulator based on the Bloch equations to aid in the teaching of topics ranging from precession...

  9. Imaging Spectroscopy: A Novel Use for the Velocity Mapped Ion Imaging Technique.

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, Jennie S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Culberson, Lori [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Strecker, Kevin E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Steill, Jeffrey D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Chandler, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The ability to measure the velocity of neutral atoms and molecules with a precision of several meter/sec provides an opportunity to measure subtle perturbations on electronic states with high resolution. Using Velocity Mapped Ion Imaging we are able to measure induced perturbations of electronic states such as broadening and magnetic and electric field splittings . We demonstrate this ability utilizing the 5s[3/2]2 → 5p[5/2]3 cycling transition at 811.5 nm in metastable Kr atoms to investigate the saturation broadening caused by Rabi cycling on a resonant transition with MHz resolution. In addition we investigate the lifetime broadening associated with ionization from the cycling states and the Zeeman splitting of the states. We discuss the inherent limits to resolution obtained with this technique.

  10. The clinical consequences of advanced imaging techniques in Barrett's esophagus

    NARCIS (Netherlands)

    Boerwinkel, David F.; Swager, Anne-Fré; Curvers, Wouter L.; Bergman, Jacques J. G. H. M.

    2014-01-01

    Evaluation of patients with Barrett's esophagus (BE) using dye-based chromoendoscopy, optical chromoendoscopy, autofluorescence imaging, or confocal laser endomicroscopy does not significantly increase the number of patients with a diagnosis of early neoplasia compared with high-definition white

  11. Development of Digital Steroscopic Imaging Technique in Mammography

    National Research Council Canada - National Science Library

    Chan, Heang

    2000-01-01

    ... for breast cancer detection, especially in dense breasts. During this year, we have assembled a high-resolution stereoscopic viewing station and developed software for displaying and manipulating stereoscopic images...

  12. A technique for the deidentification of structural brain MR images

    DEFF Research Database (Denmark)

    Bischoff-Grethe, Amanda; Ozyurt, I Burak; Busa, Evelina

    2007-01-01

    inspection showed none had brain tissue removed. In a detailed analysis of the impact of defacing on skull-stripping, 16 datasets were bias corrected with N3 (Sled et al. [1998]: IEEE Trans Med Imaging 17:87-97), defaced, and then skull-stripped using either a hybrid watershed algorithm (Ségonne et al. [2004......]: Neuroimage 22:1060-1075, in FreeSurfer) or Brain Surface Extractor (Sandor and Leahy [1997]: IEEE Trans Med Imaging 16:41-54; Shattuck et al. [2001]: Neuroimage 13:856-876); defacing did not appreciably influence the outcome of skull-stripping. Results suggested that the automatic defacing algorithm......Due to the increasing need for subject privacy, the ability to deidentify structural MR images so that they do not provide full facial detail is desirable. A program was developed that uses models of nonbrain structures for removing potentially identifying facial features. When a novel image...

  13. An accelerated image matching technique for UAV orthoimage registration

    Science.gov (United States)

    Tsai, Chung-Hsien; Lin, Yu-Ching

    2017-06-01

    Using an Unmanned Aerial Vehicle (UAV) drone with an attached non-metric camera has become a popular low-cost approach for collecting geospatial data. A well-georeferenced orthoimage is a fundamental product for geomatics professionals. To achieve high positioning accuracy of orthoimages, precise sensor position and orientation data, or a number of ground control points (GCPs), are often required. Alternatively, image registration is a solution for improving the accuracy of a UAV orthoimage, as long as a historical reference image is available. This study proposes a registration scheme, including an Accelerated Binary Robust Invariant Scalable Keypoints (ABRISK) algorithm and spatial analysis of corresponding control points for image registration. To determine a match between two input images, feature descriptors from one image are compared with those from another image. A "Sorting Ring" is used to filter out uncorrected feature pairs as early as possible in the stage of matching feature points, to speed up the matching process. The results demonstrate that the proposed ABRISK approach outperforms the vector-based Scale Invariant Feature Transform (SIFT) approach where radiometric variations exist. ABRISK is 19.2 times and 312 times faster than SIFT for image sizes of 1000 × 1000 pixels and 4000 × 4000 pixels, respectively. ABRISK is 4.7 times faster than Binary Robust Invariant Scalable Keypoints (BRISK). Furthermore, the positional accuracy of the UAV orthoimage after applying the proposed image registration scheme is improved by an average of root mean square error (RMSE) of 2.58 m for six test orthoimages whose spatial resolutions vary from 6.7 cm to 10.7 cm.

  14. A survey of GPU-based medical image computing techniques

    Science.gov (United States)

    Shi, Lin; Liu, Wen; Zhang, Heye; Xie, Yongming

    2012-01-01

    Medical imaging currently plays a crucial role throughout the entire clinical applications from medical scientific research to diagnostics and treatment planning. However, medical imaging procedures are often computationally demanding due to the large three-dimensional (3D) medical datasets to process in practical clinical applications. With the rapidly enhancing performances of graphics processors, improved programming support, and excellent price-to-performance ratio, the graphics processing unit (GPU) has emerged as a competitive parallel computing platform for computationally expensive and demanding tasks in a wide range of medical image applications. The major purpose of this survey is to provide a comprehensive reference source for the starters or researchers involved in GPU-based medical image processing. Within this survey, the continuous advancement of GPU computing is reviewed and the existing traditional applications in three areas of medical image processing, namely, segmentation, registration and visualization, are surveyed. The potential advantages and associated challenges of current GPU-based medical imaging are also discussed to inspire future applications in medicine. PMID:23256080

  15. [Statistical study of the wavelet-based lossy medical image compression technique].

    Science.gov (United States)

    Puniene, Jūrate; Navickas, Ramūnas; Punys, Vytenis; Jurkevicius, Renaldas

    2002-01-01

    Medical digital images have informational redundancy. Both the amount of memory for image storage and their transmission time could be reduced if image compression techniques are applied. The techniques are divided into two groups: lossless (compression ratio does not exceed 3 times) and lossy ones. Compression ratio of lossy techniques depends on visibility of distortions. It is a variable parameter and it can exceed 20 times. A compression study was performed to evaluate the compression schemes, which were based on the wavelet transform. The goal was to develop a set of recommendations for an acceptable compression ratio for different medical image modalities: ultrasound cardiac images and X-ray angiographic images. The acceptable image quality after compression was evaluated by physicians. Statistical analysis of the evaluation results was used to form a set of recommendations.

  16. Improvement in printing technique of spiral CT three-dimensional colour image

    International Nuclear Information System (INIS)

    Wang Yicheng; Liu Feng; Zhang Ling

    2005-01-01

    Objective: To investigate the printing technique of spiral CT three-dimensional (3D) colour image. Methods: The 3D colour images of 136 patients were printed, with the equipment of Marconi spiral CT, personnel computer, colour ink printer, and network switchboard. Results: All printed images were satisfied by this method. Conclusion: This technique is economic, simple, and useful, and can meet the need for clinical diagnosis and operation. (authors)

  17. A graphical simulator for teaching basic and advanced MR imaging techniques

    DEFF Research Database (Denmark)

    Hanson, Lars G

    2007-01-01

    for radiologists, radiographers, and technical staff alike, but it is notoriously challenging to explain spin dynamics by using traditional teaching tools. The author developed a freely available graphical simulator based on the Bloch equations to aid in the teaching of topics ranging from precession......Teaching of magnetic resonance (MR) imaging techniques typically involves considerable handwaving, literally, to explain concepts such as resonance, rotating frames, dephasing, refocusing, sequences, and imaging. A proper understanding of MR contrast and imaging techniques is crucial...

  18. Radiation protection in newer medical imaging techniques: CT colonography

    International Nuclear Information System (INIS)

    2008-01-01

    Multislice/detector computed tomography (CT) scanning, applied to visualization of the colon in CT colonography (CTC), also known as virtual colonoscopy (VC), is a relatively new application of CT introduced in recent years. The possibility of its application in population screening techniques raises a number of questions. Effort is required to ensure that the benefit of this new practice will not pose an undue level of detriment to the individual in multiple examinations. For practitioners and regulators, it is evident that innovation has been driven by both the imaging industry and by an ever increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practice lag (inevitably) behind the industrial and clinical innovations being achieved. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill this growing vacuum, by bringing up to date and timely advice to bear on the problems involved. Under its statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for worldwide application of these standards, the IAEA has developed the Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS). The BSS was issued by the IAEA and co-sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organisation (ILO), the OECD Nuclear Energy Agency (OECD/NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO), and requires radiation protection of patients undergoing medical exposures through justification of the procedures involved and through optimization. The IAEA programme on radiation protection of patients encourages the reduction of patient doses without losing diagnostic benefits. To facilitate this

  19. A comparative study on preprocessing techniques in diabetic retinopathy retinal images: illumination correction and contrast enhancement.

    Science.gov (United States)

    Rasta, Seyed Hossein; Partovi, Mahsa Eisazadeh; Seyedarabi, Hadi; Javadzadeh, Alireza

    2015-01-01

    To investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal image quality, a comparative study was carried out. We studied and implemented a few illumination correction and contrast enhancement techniques on color retinal images to find out the best technique for optimum image enhancement. To compare and choose the best illumination correction technique we analyzed the corrected red and green components of color retinal images statistically and visually. The two contrast enhancement techniques were analyzed using a vessel segmentation algorithm by calculating the sensitivity and specificity. The statistical evaluation of the illumination correction techniques were carried out by calculating the coefficients of variation. The dividing method using the median filter to estimate background illumination showed the lowest Coefficients of variations in the red component. The quotient and homomorphic filtering methods after the dividing method presented good results based on their low Coefficients of variations. The contrast limited adaptive histogram equalization increased the sensitivity of the vessel segmentation algorithm up to 5% in the same amount of accuracy. The contrast limited adaptive histogram equalization technique has a higher sensitivity than the polynomial transformation operator as a contrast enhancement technique for vessel segmentation. Three techniques including the dividing method using the median filter to estimate background, quotient based and homomorphic filtering were found as the effective illumination correction techniques based on a statistical evaluation. Applying the local contrast enhancement technique, such as CLAHE, for fundus images presented good potentials in enhancing the vasculature segmentation.

  20. Meniscal tears: comparison of half-Fourier technique and conventional MR imaging

    International Nuclear Information System (INIS)

    Shabana, Wael; Maeseneer, Michel de; Machiels, Freddy; Ridder, Filip de; Osteaux, Michel

    2003-01-01

    Purpose: To determine whether half-Fourier MR image acquisition technique can provide similar information to that of conventional MR acquisition technique for evaluation of meniscal tears. Materials and methods: We studied 101 menisci in 52 patients who were referred for evaluation of meniscal tears. Sagittal MR images of the knee were obtained for all patients by using proton density and T2-weighted SE sequences on a 1-T clinical system. The half-Fourier technique and conventional technique were used for all patients. All other imaging parameters were identical for both sequences (TR/TE=2400/20,70; 3 mm slice thickness; 200x256 matrix; field of view, 200; one signal acquired). Both sets of images were filmed with standard window and level settings. Images were randomised and interpreted independently by two radiologists for the presence of meniscal tears. Images were also subjectively assessed for image quality using a five-point grading scale. Results: On half-Fourier images, Reader 1 interpreted 23 menisci as torn, compared to 28 for Reader 2. On conventional images, Reader 1 interpreted 24 menisci as torn, compared to 26 for Reader 2. Agreement between interpretation of the conventional and that of the half-Fourier images was 99% for Reader 1, and 98% for Reader 2. Agreement between readers for the half-Fourier images was 95%, and for the conventional images 96%. No statistically significant difference was found in the subjective evaluation of image quality between the conventional and half-Fourier images. Conclusion: The half-Fourier acquisition technique compares favourably with the conventional technique for the evaluation of meniscal tears

  1. Improving the ability of image sensors to detect faint stars and moving objects using image deconvolution techniques.

    Science.gov (United States)

    Fors, Octavi; Núñez, Jorge; Otazu, Xavier; Prades, Albert; Cardinal, Robert D

    2010-01-01

    In this paper we show how the techniques of image deconvolution can increase the ability of image sensors as, for example, CCD imagers, to detect faint stars or faint orbital objects (small satellites and space debris). In the case of faint stars, we show that this benefit is equivalent to double the quantum efficiency of the used image sensor or to increase the effective telescope aperture by more than 30% without decreasing the astrometric precision or introducing artificial bias. In the case of orbital objects, the deconvolution technique can double the signal-to-noise ratio of the image, which helps to discover and control dangerous objects as space debris or lost satellites. The benefits obtained using CCD detectors can be extrapolated to any kind of image sensors.

  2. Evaluation of the effectiveness of laser crust removal on granites by means of hyperspectral imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pozo-Antonio, J.S., E-mail: santiago.pozo@udc.es [Laboratorio de Aplicacións Industriais do Láser, Centro de Investigacións Tecnolóxicas (CIT), Departamento de Enxeñaría Industrial II, Escola Politécnica Superior, Universidade de Coruña (UDC), Campus Ferrol, 15403 Ferrol (Spain); Fiorucci, M.P.; Ramil, A.; López, A.J. [Laboratorio de Aplicacións Industriais do Láser, Centro de Investigacións Tecnolóxicas (CIT), Departamento de Enxeñaría Industrial II, Escola Politécnica Superior, Universidade de Coruña (UDC), Campus Ferrol, 15403 Ferrol (Spain); Rivas, T. [Departamento de Enxeñaría dos Recursos Naturais e Medioambiente, Escola Superior de Minas, Universidade de Vigo, 36310 Vigo (Spain)

    2015-08-30

    Highlights: • Hyperspectral imaging techniques for determining the degree of crust removal on granites used in Cultural Heritage. • Hyperspectral imaging techniques allow to in situ evaluate of the effectiveness of the laser cleaning. • Hyperspectral imaging data are consistent with the information obtained by conventional techniques about the cleaning effectiveness. - Abstract: In this paper, we present a study of the application of the hyperspectral imaging technique in order to non-destructively evaluate the laser cleaning of the biogenic patina and the sulphated black crust developed on a fine-grained granite used in the construction of Cultural Heritage in NW Spain. The grained polymineral texture of the granite hinders the adjustment of laser irradiation parameters during the cleaning, and therefore the in situ process control. The cleaning was performed with a nanosecond pulsed Nd:YVO{sub 4} laser at 355 nm. A hyperspectral camera was used to in situ assess the effectiveness of cleaning by recording images of the rock surfaces before and during the laser treatment. Different analytical techniques were used to test the ability of the hyperspectral imaging technique to evaluate the cleaning process of the granite samples: optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM - EDX), Fourier transform infrared spectroscopy (FTIR) and spectrophotometer colour measurements. The results indicated that hyperspectral imaging technique is a reliable and more affordable technique to in situ evaluate the process of laser cleaning of the biogenic patina and the sulphated black crust in fine-grained granites.

  3. Magnetic resonance imaging acquisition techniques intended to decrease movement artefact in paediatric brain imaging: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Woodfield, Julie [University of Edinburgh, Child Life and Health, Edinburgh (United Kingdom); Kealey, Susan [Western General Hospital, Department of Neuroradiology, Edinburgh (United Kingdom)

    2015-08-15

    Attaining paediatric brain images of diagnostic quality can be difficult because of young age or neurological impairment. The use of anaesthesia to reduce movement in MRI increases clinical risk and cost, while CT, though faster, exposes children to potentially harmful ionising radiation. MRI acquisition techniques that aim to decrease movement artefact may allow diagnostic paediatric brain imaging without sedation or anaesthesia. We conducted a systematic review to establish the evidence base for ultra-fast sequences and sequences using oversampling of k-space in paediatric brain MR imaging. Techniques were assessed for imaging time, occurrence of movement artefact, the need for sedation, and either image quality or diagnostic accuracy. We identified 24 relevant studies. We found that ultra-fast techniques had shorter imaging acquisition times compared to standard MRI. Techniques using oversampling of k-space required equal or longer imaging times than standard MRI. Both ultra-fast sequences and those using oversampling of k-space reduced movement artefact compared with standard MRI in unsedated children. Assessment of overall diagnostic accuracy was difficult because of the heterogeneous patient populations, imaging indications, and reporting methods of the studies. In children with shunt-treated hydrocephalus there is evidence that ultra-fast MRI is sufficient for the assessment of ventricular size. (orig.)

  4. Application of Reflectance Transformation Imaging Technique to Improve Automated Edge Detection in a Fossilized Oyster Reef

    Science.gov (United States)

    Djuricic, Ana; Puttonen, Eetu; Harzhauser, Mathias; Dorninger, Peter; Székely, Balázs; Mandic, Oleg; Nothegger, Clemens; Molnár, Gábor; Pfeifer, Norbert

    2016-04-01

    . One source of light for shading does show all morphologic features needed for description. Additionally, more details such as fault lines, overlaps and characteristic edges of complex shell structures are clearly detected by simply changing the illumination on the shaded digital surface model. In a further study, the potential of edge detection of the individual shells will be analyzed based on statistical analysis by keeping track of the local accumulative shading gradient. The results are compared to manually identified edges. In a following study phase, the detected edges will be improved by graph cut segmentation. We assume that this technique can lead to automatically extracted teaching set for object segmentation on a complex environment. The project is supported by the Austrian Science Fund (FWF P 25883-N29).

  5. Digital radiography and advanced imaging techniques in dentistry

    Directory of Open Access Journals (Sweden)

    Burcu Keles Evlice

    2013-04-01

    Full Text Available Since the discovery of x-rays in 1895, film has been the primary medium for capturing, displaying and storing radiographic images. Digital or filmless radiography is slowly being adopted by the dental profession. Digital radiography offers a number of capabilities compared with conventional radiography, such as postprocessing, electronic archiving, concurrent access to images, and improved data distribution. Computer based applications which are used for quantitative measurements and evaluations on digital images for better user interpretation. New diagnostic imaging processes are improved connected with the technological progress of computer systems. Since the first clinical use of computed tomography (CT scans in 1972, technological development has been rapid. Dental volumetric tomography (DVT, uniquely used for dentomaxillofacial imaging came to the market owing to recent rapid developments in digital radiology technology and is becoming more popular in dental applications. Low radiation dose cone beam computed tomography (CBCT units that are commercially available at a lower cost than CT units, has performed valuable diagnostic information for dentists. [Archives Medical Review Journal 2013; 22(2.000: 230-238

  6. Volume holographic imaging endoscopic design and construction techniques.

    Science.gov (United States)

    Howlett, Isela D; Han, Wanglei; Gordon, Michael; Rice, Photini; Barton, Jennifer K; Kostuk, Raymond K

    2017-05-01

    A reflectance volume holographic imaging (VHI) endoscope has been designed for simultaneous in vivo imaging of surface and subsurface tissue structures. Prior utilization of VHI systems has been limited to ex vivo tissue imaging. The VHI system presented in this work is designed for laparoscopic use. It consists of a probe section that relays light from the tissue sample to a handheld unit that contains the VHI microscope. The probe section is constructed from gradient index (GRIN) lenses that form a 1:1 relay for image collection. The probe has an outer diameter of 3.8 mm and is capable of achieving 228.1 ?? lp / mm resolution with 660-nm Kohler illumination. The handheld optical section operates with a magnification of 13.9 and a field of view of 390 ?? ? m × 244 ?? ? m . System performance is assessed through imaging of 1951 USAF resolution targets and soft tissue samples. The system has also passed sterilization procedures required for surgical use and has been used in two laparoscopic surgical procedures.

  7. Interferometry imaging technique for accurate deep-space probe positioning

    Science.gov (United States)

    Zheng, Weimin; Tong, Fengxian; Zhang, Juan; Liu, Lei; Shu, Fengchun

    2017-12-01

    Very long baseline interferometry (VLBI) is a radio astronomy tool with very high spatial resolution. It uses two or more radio telescopes to track the faraway object and gets its visibility. The intensity distribution image of radio source can be obtained by the inverse Fourier transformation of the visibilities sampled on UV plane perpendicular to the line of sight. Chinese VLBI Network (CVN) consists of 5 radio telescopes, and its highest spatial resolution is equivalent to that of a ∼3000 km diameters single dish antenna. This paper introduces the interferometry imaging principle, the imaging results of ChangE lunar and Mars Express probes. The measured ChangE-3 (CE-3) Rover relative position accuracy is about 1 m by this method. The 1 m accuracy is verified by comparisons with Rover null position and the onboard stereo vision measurement results. The successful imaging of spacecraft indicates that the interferometry imaging technology can be used for accurate spacecraft positioning in the future.

  8. Technology and Technique Standards for Camera-Acquired Digital Dermatologic Images: A Systematic Review.

    Science.gov (United States)

    Quigley, Elizabeth A; Tokay, Barbara A; Jewell, Sarah T; Marchetti, Michael A; Halpern, Allan C

    2015-08-01

    Photographs are invaluable dermatologic diagnostic, management, research, teaching, and documentation tools. Digital Imaging and Communications in Medicine (DICOM) standards exist for many types of digital medical images, but there are no DICOM standards for camera-acquired dermatologic images to date. To identify and describe existing or proposed technology and technique standards for camera-acquired dermatologic images in the scientific literature. Systematic searches of the PubMed, EMBASE, and Cochrane databases were performed in January 2013 using photography and digital imaging, standardization, and medical specialty and medical illustration search terms and augmented by a gray literature search of 14 websites using Google. Two reviewers independently screened titles of 7371 unique publications, followed by 3 sequential full-text reviews, leading to the selection of 49 publications with the most recent (1985-2013) or detailed description of technology or technique standards related to the acquisition or use of images of skin disease (or related conditions). No universally accepted existing technology or technique standards for camera-based digital images in dermatology were identified. Recommendations are summarized for technology imaging standards, including spatial resolution, color resolution, reproduction (magnification) ratios, postacquisition image processing, color calibration, compression, output, archiving and storage, and security during storage and transmission. Recommendations are also summarized for technique imaging standards, including environmental conditions (lighting, background, and camera position), patient pose and standard view sets, and patient consent, privacy, and confidentiality. Proposed standards for specific-use cases in total body photography, teledermatology, and dermoscopy are described. The literature is replete with descriptions of obtaining photographs of skin disease, but universal imaging standards have not been developed

  9. Electromagnetic Scattered Field Evaluation and Data Compression Using Imaging Techniques

    Science.gov (United States)

    Gupta, I. J.; Burnside, W. D.

    1996-01-01

    This is the final report on Project #727625 between The Ohio State University and NASA, Lewis Research Center, Cleveland, Ohio. Under this project, a data compression technique for scattered field data of electrically large targets is developed. The technique was applied to the scattered fields of two targets of interest. The backscattered fields of the scale models of these targets were measured in a ra compact range. For one of the targets, the backscattered fields were also calculated using XPATCH computer code. Using the technique all scattered field data sets were compressed successfully. A compression ratio of the order 40 was achieved. In this report, the technique is described briefly and some sample results are included.

  10. AOTF-based optical system of a microscope module for multispectral imaging techniques

    Science.gov (United States)

    Polschikova, Olga; Machikhin, Alexander; Batshev, Vladislav; Ramazanova, Alina; Belov, Artyom; Pozhar, Vitold

    2017-12-01

    Multi-spectral imaging techniques are widely used in microscopy for many applications. One of the most widespread spectral elements for this purpose is an imaging acousto-optic tunable filter (AOTF). AOTF-based contrast visualization is especially effective when used together with other imaging techniques. Simultaneous utilization of two or more imagers requires optical coupling to provide point-to-point matching of the obtained images. Small linear and angular aperture of AOTF additionally hampers the development of multi-sensor imaging systems for microscopy. In this paper, we present a compact optical system which allows to integrate AOTF-based spectral imager into the schemes of conventional microscopes and provide high-quality spectral image of the same scale as in another, for example, wideband channel. The effectiveness of the proposed approach is demonstrated experimentally.

  11. Imaging of mass distribution in paper by electrography technique, (3)

    International Nuclear Information System (INIS)

    Tomimasu, Hiroshi; Baba, Susumu; Luner, P.

    1991-01-01

    Characteristics of photographic films and a TV monitor system as electron beam detectors were studied. A photographic film with thin emulsion layer showed a peak in the basis weight calibration curve because of its limited absorption of electron energy. On the other hand, a photographic film with thick emulsion layer showed no peak and provided wide measurable basis weight range. However, films with thick emulsion layer were found unsuitable for practical use since it requires very long development time. Real-time mass distribution image of a paper sample were obtained with a TV monitor system for transmission electron microscope combined with an image analyzer. The system can image the sample of 11x9 mm with spatial resolution of 20 μm at different electron accelerating voltages. The TV monitor system gave no peak in the basis weight calibration curve and provided wide measurable basis weight range. (author)

  12. Fundus imaging with a mobile phone: A review of techniques

    Directory of Open Access Journals (Sweden)

    Mahesh P Shanmugam

    2014-01-01

    Full Text Available Fundus imaging with a fundus camera is an essential part of ophthalmic practice. A mobile phone with its in-built camera and flash can be used to obtain fundus images of reasonable quality. The mobile phone can be used as an indirect ophthalmoscope when coupled with a condensing lens. It can be used as a direct ophthalmoscope after minimal modification, wherein the fundus can be viewed without an intervening lens in young patients with dilated pupils. Employing the ubiquitous mobile phone to obtain fundus images has the potential for mass screening, enables ophthalmologists without a fundus camera to document and share findings, is a tool for telemedicine and is rather inexpensive.

  13. Surgical Techniques and Imaging Complications of Liver Transplant.

    Science.gov (United States)

    Baheti, Akshay D; Sanyal, Rupan; Heller, Matthew T; Bhargava, Puneet

    2016-03-01

    Liver transplant is the treatment of choice for end-stage liver disease. Management of transplant patients requires a multidisciplinary approach, with radiologists playing a key role in identifying complications in both symptomatic and asymptomatic patients. Ultrasonography remains the investigation of choice for the initial evaluation of symptomatic patients. Depending on the clinical situation, further evaluation with CT, MRI, or biopsy may be performed or clinical and imaging surveillance may be continued. This article discusses the various normal and abnormal imaging presentations of liver transplant patients, including various acute and chronic complications, and their management. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Investigations of Antiangiogenic Mechanisms Using Novel Imaging Techniques

    Science.gov (United States)

    2011-02-01

    fold was excised, and approximately 20,000 4T1 murine mammary carcinoma cells were injected into the underlying fascia . A cover glass was placed over... planted in dorsal skin fold window chambers in nude mice. Surgery and imaging were carried out under ketamine–xylazine and isoflurane anesthesia, re

  15. An improved technique for the prediction of optimal image resolution ...

    African Journals Online (AJOL)

    Past studies to predict optimal image resolution required for generating spatial information for savannah ecosystems have yielded different outcomes, hence providing a knowledge gap that was investigated in the present study. The postulation, for the present study, was that by graphically solving two simultaneous ...

  16. [Basics of MRI technique and MRI image interpretation].

    Science.gov (United States)

    Imhof, H; Rand, T; Trattnig, S; Kramer, J

    1994-09-01

    Today magnetic resonance imaging (MRI) is an important routine diagnostic tool in orthopaedics. It is based on the nuclear magnetic resonance phenomenon: "free" hydrogen atoms (mainly from water) become field-parallel in a strong outer magnetic field. They reach a higher energy level by application of an additional electromagnetic field. After shutdown of this outer field the atoms send out electromagnetic waves (radiowaves), representing the MR signal. Different amounts of "free" water result in various image characteristics. Typically, a higher tissue water content is represented by high MR signals, e.g. in blastomas, inflammations and degenerative changes. Waterless structures such as calcified or fibrous tissues, tendons and ligaments show low MR signals. Fatty structures have high signals; proteins dissolved in "free" water change the water signal dramatically. Besides these basic parameters, para-, ferro- and super-paramagnetic materials--ether naturally present in the human body, such as methemoglobin, or artificially introduced, such as MR contrast media--and flow are responsible for different grey shades in MRI. MRI is not associated with ionizing radiation and allows imaging in all planes without changing the patient's position. Disadvantages of MRI are high costs and low availability. Future technical developments will result in shorter imaging times and broadening of the application spectrum, leading towards "MR fluoroscopy" and MR interventions.

  17. Experimental study of bubbly flow using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yucheng, E-mail: ycfu@vt.edu; Liu, Yang, E-mail: liu130@vt.edu

    2016-12-15

    This paper presents an experimental study of bubbly flows at relatively high void fractions using an advanced image processing method. Bubble overlapping is a common problem in such flows and the past studies often treat the overlapping bubbles as a whole, which introduces considerable measurement uncertainties. In this study, a hybrid method combining intersection point detection and watershed segmentation is used to separate the overlapping bubbles. In order to reconstruct bubbles from separated segments, a systematic procedure is developed which can preserve more features captured in the raw image compared to the simple ellipse fitting method. The distributions of void fraction, interfacial area concentration, number density and velocity are obtained from the extracted bubble information. High-speed images of air-water bubbly flows are acquired and processed for eight test runs conducted in a 30 mm × 10 mm rectangular channel. The developed image processing scheme can effectively separate overlapping bubbles and the results compare well with the measurements by the gas flow meter and double-sensor conductivity probe. The development of flows in transverse and mainstream directions are analyzed and compared with the prediction made by the one-dimensional interfacial area transport equation (IATE) and the bubble number density transport equation.

  18. A study of correlation technique on pyramid processed images

    Indian Academy of Sciences (India)

    Currently, research is aimed at understanding how the human visual system interprets and processes image information, that ... Each spatial-frequency band in the human visual system is responsive to approximately one octave of spatial ... This redundant information is a waste of both memory storage and processing time.

  19. An efficient similarity measure technique for medical image registration

    Indian Academy of Sciences (India)

    The similarity measures are tested on the matrix laboratory (MATLAB) plat- form of version 7.0.4. Table 4 shows the comparison of computational time required by various image registration methods. Figures 5a and c of the size 256 × 256 pixels are considered for the calculation of computational time of various similarity ...

  20. A proposed security technique based on watermarking and encryption for digital imaging and communications in medicine

    Directory of Open Access Journals (Sweden)

    Mohamed M. Abd-Eldayem

    2013-03-01

    Full Text Available Nowadays; modern Hospital Data Management Systems (HDMSs are applied in a computer network; in addition medicinal equipments produce medical images in a digital form. HDMS must store and exchange these images in a secured environment to provide image integrity and patient privacy. The reversible watermarking techniques can be used to provide the integrity and the privacy. In this paper, a security technique based on watermarking and encryption is proposed to be used for Digital Imaging and Communications in Medicine (DICOM. It provides patient authentication, information confidentiality and integrity based on reversible watermark. To achieve integrity service at the sender side; a hash value based on encrypted MD5 is determined from the image. And to satisfy the reversible feature; R–S-Vector is determined from the image and is compressed based on a Huffman compression algorithm. After that to provide confidentiality and authentication services: the compressed R–S-Vector, the hash value and patient ID are concatenated to form a watermark then this watermark is encrypted using AES encryption technique, finally the watermark is embedded inside the medical image. Experimental results prove that the proposed technique can provide patient authentication services, image integrity service and information confidentiality service with excellent efficiency. Concluded results for all tested DICOM medical images and natural images show the following: BER equals 0, both of SNR and PSNR are consistent and have large values, and MSE has low value; the average values of SNR, PSNR and MSE are 52 dB, 57 dB and 0.12 respectively. Therefore, watermarked images have high imperceptibility, invisibility and transparency. In addition, the watermark extracted from the image at the receiver side is identical to the watermark embedded into the image in the sender side; as a result, the proposed technique is totally reversible, and the embedded watermark does not

  1. Terahertz imaging technique and application in large scale integrated circuit failure inspection

    Science.gov (United States)

    Di, Zhi-gang; Yao, Jian-quan; Jia, Chun-rong; Xu, De-gang; Bing, Pi-bin; Yang, Peng-fei; Zheng, Yi-bo

    2010-11-01

    Terahertz ray, as a new style optic source, usually means the electromagnetic whose frequencies lies in between 0.1THz~10THz, the waveband region of the electromagnetic spectrum lies in the gap between microwaves and infrared ray. With the development of laser techniques, quantum trap techniques and compound semiconductor techniques, many new terahertz techniques have been pioneered, motivated in part by the vast range of possible applications for terahertz imaging, sensing, and spectroscopy. THz imaging technique was introduced, and THz imaging can give us not only the density picture but also the phase information within frequency domain. Consequently, images of suspicious objects such as concealed metallic or metal weapons are much sharper and more readily identified when imaged with THz imaging scanners. On the base of these, the application of THz imaging in nondestructive examination, more concretely in large scale circuit failure inspection was illuminated, and the important techniques of this application were introduced, also future prospects were discussed. With the development of correlative technology of THz, we can draw a conclusion that THz imaging technology will have nice application foreground.

  2. Quality comparison between DEF-10 digital image from simulation technique and Computed Tomography (CR) technique in industrial radiography

    International Nuclear Information System (INIS)

    Siti Nur Syatirah Ismail

    2012-01-01

    The study was conducted to make comparison of digital image quality of DEF-10 from the techniques of simulation and computed radiography (CR). The sample used is steel DEF-10 with thickness of 15.28 mm. In this study, the sample is exposed to radiation from X-ray machine (ISOVOLT Titan E) with certain parameters. The parameters used in this study such as current, volt, exposure time and distance are specified. The current and distance of 3 mA and 700 mm respectively are specified while the applied voltage varies at 140, 160, 180 and 200 kV. The exposure time is reduced at a rate of 0, 20, 40, 60 and 80 % for each sample exposure. Digital image of simulation produced from aRTist software whereas digital image of computed radiography produced from imaging plate. Therefore, both images were compared qualitatively (sensitivity) and quantitatively (Signal to-Noise Ratio; SNR, Basic Spatial Resolution; SRb and LOP size) using Isee software. Radiographic sensitivity is indicated by Image Quality Indicator (IQI) which is the ability of the CR system and aRTist software to identify IQI of wire type when the time exposure is reduced up to 80% according to exposure chart ( D7; ISOVOLT Titan E). The image of the thinnest wire diameter achieved by radiograph from simulation and CR are the wire numbered 7 rather than the wire numbered 8 required by the standard. In quantitative comparison, this study shows that the SNR values decreases with reducing exposure time. SRb values increases for simulation and decreases for CR when the exposure time decreases and the good image quality can be achieved at 80% reduced exposure time. The high SNR and SRb values produced good image quality in CR and simulation techniques respectively. (author)

  3. Molecular imaging with optics: primer and case for near-infrared fluorescence techniques in personalized medicine

    Science.gov (United States)

    Sevick-Muraca, Eva M.; Rasmussen, John C.

    2010-01-01

    We compare and contrast the development of optical molecular imaging techniques with nuclear medicine with a didactic emphasis for initiating readers into the field of molecular imaging. The nuclear imaging techniques of gamma scintigraphy, single-photon emission computed tomography, and positron emission tomography are first briefly reviewed. The molecular optical imaging techniques of bioluminescence and fluorescence using gene reporter/probes and gene reporters are described prior to introducing the governing factors of autofluorescence and excitation light leakage. The use of dual-labeled, near-infrared excitable and radio-labeled agents are described with comparative measurements between planar fluorescence and nuclear molecular imaging. The concept of time-independent and -dependent measurements is described with emphasis on integrating time-dependent measurements made in the frequency domain for 3-D tomography. Finally, we comment on the challenges and progress for translating near-infrared (NIR) molecular imaging agents for personalized medicine. PMID:19021311

  4. Comparison of magnetoencephalography with other functional imaging techniques.

    Science.gov (United States)

    Ioannides, A A

    1991-01-01

    Recent advances in instrumentation and analysis in biomagnetism offer a unique tool for studying the spatiotemporal evolution of spontaneous brain activity as well as activity evoked by a stimulus. The overall performance characteristics of this and other techniques used to study the dynamics of brain function are compared. Particular emphasis is placed on defining the general spatiotemporal window of brain activity that each technique makes accessible. Similarities and differences associated with diverse modelling schemes for extracting source current density properties from electrographic recordings are stated.

  5. Comparison of mosaicking techniques for airborne images from consumer-grade cameras

    Science.gov (United States)

    Song, Huaibo; Yang, Chenghai; Zhang, Jian; Hoffmann, Wesley Clint; He, Dongjian; Thomasson, J. Alex

    2016-01-01

    Images captured from airborne imaging systems can be mosaicked for diverse remote sensing applications. The objective of this study was to identify appropriate mosaicking techniques and software to generate mosaicked images for use by aerial applicators and other users. Three software packages-Photoshop CC, Autostitch, and Pix4Dmapper-were selected for mosaicking airborne images acquired from a large cropping area. Ground control points were collected for georeferencing the mosaicked images and for evaluating the accuracy of eight mosaicking techniques. Analysis and accuracy assessment showed that Pix4Dmapper can be the first choice if georeferenced imagery with high accuracy is required. The spherical method in Photoshop CC can be an alternative for cost considerations, and Autostitch can be used to quickly mosaic images with reduced spatial resolution. The results also showed that the accuracy of image mosaicking techniques could be greatly affected by the size of the imaging area or the number of the images and that the accuracy would be higher for a small area than for a large area. The results from this study will provide useful information for the selection of image mosaicking software and techniques for aerial applicators and other users.

  6. Segmentation Technique for Image Indexing and Retrieval on Discrete Cosines Domain

    Directory of Open Access Journals (Sweden)

    Suhendro Yusuf Irianto

    2013-03-01

    Full Text Available This paper uses region growing segmentation technique to segment the Discrete Cosines (DC  image. The problem of content Based image retrieval (CBIR is the luck of accuracy in matching between image query and image in the database as it matches object and background in the same time.   This the reason previous CBIR techniques inaccurate and time consuming. The CBIR   based on the segmented region proposed in this work  separates object from background as CBIR need only match the object not the background.  By using region growing technique on DC image, it reduces the number of image       regions.    The proposed of recursive region growing is not new technique but its application on DC images to build    indexing keys is quite new and not yet presented by many     authors. The experimental results show  that the proposed methods on   segmented images present good precision which are higher than 0.60 on all classes . It can be concluded that  region growing segmented based CBIR more efficient    compare to DC images  in term of their precision 0.59 and 0.75, respectively. Moreover,  DC based CBIR  can save time and simplify algorithm compare to DCT images.

  7. Dose classification scheme for digital imaging techniques in diagnostic radiology

    International Nuclear Information System (INIS)

    Hojreh, A.

    2002-04-01

    Purpose: image quality in diagnostic radiology is determined in crucial extent by the signal-noise-ratio, which is proportional to the applied x-ray dose. Onward technological developments in the diagnostic radiology are therefore frequently connected with a dose increase, which subjectively is hardly or even not perceptible. The aim of this work was to define reproducible standards for image quality as a function of dose and expected therapeutical consequence in case of computed tomography of the paranasal sinuses and the upper and lower jaw (dental CT), whereby practical-clinical purposes are considered. Materials and methods: the image quality of computed tomography of the paranasal sinuses and dental CT was determined by standard deviation of the CT-numbers (pixel noise) in a region of interest of the phantom of American Association of Physicists in Medicine (AAPM phantom) and additionally in the patients CT images. The diagnostic quality of the examination was classified on the basis of patients CT images in three dose levels (low dose, standard dose and high dose). Results: the pixel noise of CT of the paranasal sinuses with soft tissue reconstruction amounts to 19.3 Hounsfield units (HU) for low dose, 8.8 HU for standard dose, and below 8 HU for high dose. The pixel noise of the dental CT with bone (high resolution) reconstruction amounts to 344 HU for low dose, 221 HU for standard dose, and below 200 HU for high dose. Suitable indications for low dose CT are the scanning of body regions with high contrast differences, like the bony delimitations of air-filled spaces of the facial bones, and radiological follow-up examinations with dedicated questions such as axis determination in dental implantology, as well as the images of objects with small diameter such as in case of children. The standard dose CT can be recommended for all cases, in which precise staging of the illness plays an indispensable role for the diagnosis and therapy planning. With high dose

  8. Optimal scan timing of hepatic arterial-phase imaging of hypervascular hepatocellular carcinoma determined by multiphasic fast CT imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Kagawa, Yuki; Okada, Masahiro; Yagyu, Yukinobu; Kumano, Seishi; Murakami, Takamichi [Dept. of Radiology, Kinki Univ. Faculty of Medicine, Osaka (Japan)], e-mail: murakami@med.kindai.ac.jp; Kanematsu, Masayuki [Dept. of Radiology, Gifu Univ., School of Medicine, Gifu (Japan); Kudo, Masayuki [CT Research JP, GE Healthcare JP Corporation, Tokyo (Japan)

    2013-10-15

    Background: A new multiphasic fast imaging technique, known as volume helical shuttle technique, is a breakthrough for liver imaging that offers new clinical opportunities in dynamic blood flow studies. This technique enables virtually real-time hemodynamics assessment by shuttling the patient cradle back and forth during serial scanning. Purpose: To determine optimal scan timing of hepatic arterial-phase imaging for detecting hypervascular hepatocellular carcinoma (HCC) with maximum tumor-to-liver contrast by volume helical shuttle technique. Material and Methods: One hundred and one hypervascular HCCs in 50 patients were prospectively studied by 64-channel multidetector-row computed tomography (MDCT) with multiphasic fast imaging technique. Contrast medium containing 600 mg iodine per kg body weight was intravenously injected for 30 s. Six seconds after the contrast arrival in the abdominal aorta detected with bolus tracking, serial 12-phase imaging of the whole liver was performed during 24-s breath-holding with multiphasic fast imaging technique during arterial phase. By placing regions of interest in the abdominal aorta, portal vein, liver parenchyma, and hypervascular HCCs on the multiphase images, time-density curves of anatomical regions and HCCs were composed. Timing of maximum tumor-to-liver contrast after the contrast arrival in the abdominal aorta was determined. Results: For the detection of hypervascular HCC at arterial phase, mean time and value of maximum tumor-to-liver contrast after the contrast arrival were 21 s and 38.0 HU, respectively. Conclusion: Optimal delay time for the hepatic arterial-phase imaging maximizing the contrast enhancement of hypervascular HCCs was 21 s after arrival of contrast medium in the abdominal aorta.

  9. Analysis of Incremental Growth in Image Steganography Techniques for Various Parameters

    OpenAIRE

    Rajkumar Yadav

    2011-01-01

    Data hiding techniques are getting very large support from research community during the last two decades. Steganography is the widely used technique during the last few years for data hiding. Steganography is the art and science of hiding the data in some cover media like image file, audio file, video file, text file etc. Out of the various cover media available image file is the most widely used cover media. There are many techniques that are widely used for image steganagraphy during the l...

  10. Enhancement of SAR images using fuzzy shrinkage technique in ...

    Indian Academy of Sciences (India)

    Shivakumara Swamy Puranik Math

    2017-08-03

    Aug 3, 2017 ... fuzzy techniques, such as fuzzy clustering, fuzzy rule-based approach, and fuzzy integration approach. In the proposed work, the fuzzy membership is modified using Eq. (12). After the membership value is modified defuzzification process is applied with the help of Eq. (13). Denoised coefficients are.

  11. Human exhalation characterization with the aid of schlieren imaging technique

    DEFF Research Database (Denmark)

    Xu, Chunwen; Nielsen, Peter Vilhelm; Liu, Li

    2017-01-01

    Highlights •Noninvasive schlieren technique was applied to characterize human exhalation. •New methods were proposed to predict exhaled velocity um and up, respectively. •Potential infection risk depended on breathing patterns and spatial distribution of exhaled air. •New data was added to airflow...... dynamics of human breathing and CFD boundary settings....

  12. Application of digital techniques to the restoration of radiographic images

    International Nuclear Information System (INIS)

    Burch, S.F.

    1980-09-01

    The methods of constrained least squares and maximum entropy have been used to restore digital X and γ-ray radiographs. Both methods require the blurring of the image to be a linear, spatially invariant process. Although the blurring processes in radiography can be complex, situations have been identified where these simplifying assumptions are valid. Algorithms for deriving the point-spread function of each image are discussed. These include a pinhole method for X-ray radiographs, and reconstruction from edge profiles for γ-ray radiographs. The results from the restoration of geometrically blurred radiographs of sparking plugs are given. Maximum entropy gives results superior to those obtained by constrained least squares. The resolution is improved by a factor of about three when maximum entropy is used, and by a factor of about two for constrained least squares. (author)

  13. A technique for the deidentification of structural brain MR images

    DEFF Research Database (Denmark)

    Bischoff-Grethe, Amanda; Ozyurt, I Burak; Busa, Evelina

    2007-01-01

    . All voxels outside the mask with a nonzero probability of being a facial feature are set to 0. The algorithm was applied to 342 datasets that included two different T1-weighted pulse sequences and four different diagnoses (depressed, Alzheimer's, and elderly and young control groups). Visual......Due to the increasing need for subject privacy, the ability to deidentify structural MR images so that they do not provide full facial detail is desirable. A program was developed that uses models of nonbrain structures for removing potentially identifying facial features. When a novel image...... is presented, the optimal linear transform is computed for the input volume (Fischl et al. [2002]: Neuron 33:341-355; Fischl et al. [2004]: Neuroimage 23 (Suppl 1):S69-S84). A brain mask is constructed by forming the union of all voxels with nonzero probability of being brain and then morphologically dilated...

  14. Role of imaging techniques in the evaluation of cardiovascular drugs

    International Nuclear Information System (INIS)

    Sugishita, Yasuro; Matsuda, Mitsuo; Ajisaka, Ryuichi

    1985-01-01

    In order to investigate the role of imaging in the evaluation of medical treatment in heart diseases, radionuclide angiocardiography, echocardiography and Doppler echocardiography were applied in the cases of various kinds of heart diseases. Acute and chronic effects of antianginal drugs (nitrates, calcium antagonists and beta-blockers) could be evaluated by exercise radionuclide angiocardiography or exercise echocardiography in the cases of effort angina. The effects of the drugs changing myocardial contractility, preload or afterload could be evaluated by echocardiography in various kinds of heart diseases, including valvular heart biseases. The effect of calcium antagonists in improving diastolic function in hypertrophic cardiomyopathy could be evaluated by echocardiography or Doppler echocardiography. In conclusion, imaging techniqus are valuable and useful methods to evaluate the effects of cardiovascular drugs, by offering various informations. (author)

  15. An application of image processing techniques in computed tomography image analysis

    DEFF Research Database (Denmark)

    McEvoy, Fintan

    2007-01-01

    number of animals and image slices, automation of the process was desirable. The open-source and free image analysis program ImageJ was used. A macro procedure was created that provided the required functionality. The macro performs a number of basic image processing procedures. These include an initial...... process designed to remove the scanning table from the image and to center the animal in the image. This is followed by placement of a vertical line segment from the mid point of the upper border of the image to the image center. Measurements are made between automatically detected outer and inner...... boundaries of subcutaneous adipose tissue along this line segment. This process was repeated as the image was rotated (with the line position remaining unchanged) so that measurements around the complete circumference were obtained. Additionally, an image was created showing all detected boundary points so...

  16. A new imaging riometer based on Mills Cross technique

    OpenAIRE

    Grill, M.; Honary, F.; Nielsen, E.; Hagfors, T.; Dekoulis, G.; Chapman, P.; Yamagishi, H.

    2003-01-01

    A new type of imaging riometer system based on a Mills Cross antenna array is currently under construction by the Ionosphere and Radio Propagation Group, Department of Communication Systems, Lancaster in collaboration with the Max-Planck-Institut für Aeronomie, Germany. The system will have an unprecedented spatial resolution in a viewing area of 300x300km. It is located at Ramfjordmoen, near Tromsø, Norway. The riometer (relative ionospheric opacity meter) determines the radio-wave absorptio...

  17. Analysis of Interactive Image Cleansing via Raster-Processing Techniques.

    Science.gov (United States)

    1983-11-01

    utilizeI for cleansing binary imagery in a fast and effective manner via nine programed functions, which ar( herein described and illustrated. r~iDO 73...Arospace Corporation (GA) for the STARAN associative array ’ ,processor. The STARAN is a hgh -speed processor that uses a series of . omemory arrays, which... fast , easily operated image-cleansing algorithm. A few problems, however, were encountered with the initial version of the RASTER PM. 9. The major

  18. Synthetic Aperture Sequential Beamforming and other Beamforming Techniques in Ultrasound Imaging

    DEFF Research Database (Denmark)

    Kortbek, Jacob

    deviation below 5±. The two synthetic aperture imaging techniques described in this thesis are both candidates for a realistic implementation in a commercial scanner. In one technique synthetic aperture focusing (SAF) is applied to 2-dimensional imaging with a single rotating mechanically focused concave...... element. Emission and reception are done while the transducer element continuously rotates and the received RF signals are stored. The geometrical focal point can be considered as a point source emitting a spherical wave in a limited angular region. For each image point in a high resolution image line...

  19. Registering plant dysfunction in artificial biosystems through fluorescence imaging technique

    Science.gov (United States)

    Nikolova, Alexandra; Krumov, Alexandar; Vassilev, Vesselin

    Humanity ambitions in space exploration and long-term men-operated space missions evoke an increasing interest to artificial ecosystem researches. Advanced studies of plant biosystems provoke development of new innovative technologies for plant cultivation in man-made environment. Closed ecosystems of different types and structure are now used for space horticulture, cultivation of genetically modified species, bio-products for pharmacies and industry etc. New technologies are required to monitor and control basic parameters of future bioregenerative life support system, especially of plants photosynthetic activity as the most fundamental biological process. Authors propose a conception for a non-invasive control of plant physiological status in closed biosystem through spatial registration of chlorophyll fluorescence. This approach allows an early detection of stress impact on plants, reveal the dynamic and direction of the negative influence and the level of plant stress. Technical requirements for obtaining plant fluorescence images are examined in close relation with plant illumination conditions. Problems related with optimised plant illumination are discussed. Examples of fluorescence images of healthy and stressed plants demonstrate the sensibility and rapidity of signal changes caused by plant dysfunction. Proposed conception could be used for developing new technical solutions in autocontrolled bio-support systems, based on real time analysis of fluorescence images.

  20. Infrared image gray adaptive adjusting enhancement algorithm based on gray redundancy histogram-dealing technique

    Science.gov (United States)

    Hao, Zi-long; Liu, Yong; Chen, Ruo-wang

    2016-11-01

    In view of the histogram equalizing algorithm to enhance image in digital image processing, an Infrared Image Gray adaptive adjusting Enhancement Algorithm Based on Gray Redundancy Histogram-dealing Technique is proposed. The algorithm is based on the determination of the entire image gray value, enhanced or lowered the image's overall gray value by increasing appropriate gray points, and then use gray-level redundancy HE method to compress the gray-scale of the image. The algorithm can enhance image detail information. Through MATLAB simulation, this paper compares the algorithm with the histogram equalization method and the algorithm based on gray redundancy histogram-dealing technique , and verifies the effectiveness of the algorithm.

  1. Watermark Compression in Medical Image Watermarking Using Lempel-Ziv-Welch (LZW) Lossless Compression Technique.

    Science.gov (United States)

    Badshah, Gran; Liew, Siau-Chuin; Zain, Jasni Mohd; Ali, Mushtaq

    2016-04-01

    In teleradiology, image contents may be altered due to noisy communication channels and hacker manipulation. Medical image data is very sensitive and can not tolerate any illegal change. Illegally changed image-based analysis could result in wrong medical decision. Digital watermarking technique can be used to authenticate images and detect as well as recover illegal changes made to teleradiology images. Watermarking of medical images with heavy payload watermarks causes image perceptual degradation. The image perceptual degradation directly affects medical diagnosis. To maintain the image perceptual and diagnostic qualities standard during watermarking, the watermark should be lossless compressed. This paper focuses on watermarking of ultrasound medical images with Lempel-Ziv-Welch (LZW) lossless-compressed watermarks. The watermark lossless compression reduces watermark payload without data loss. In this research work, watermark is the combination of defined region of interest (ROI) and image watermarking secret key. The performance of the LZW compression technique was compared with other conventional compression methods based on compression ratio. LZW was found better and used for watermark lossless compression in ultrasound medical images watermarking. Tabulated results show the watermark bits reduction, image watermarking with effective tamper detection and lossless recovery.

  2. A Novel Technique for Shape Feature Extraction Using Content Based Image Retrieval

    Directory of Open Access Journals (Sweden)

    Dhanoa Jaspreet Singh

    2016-01-01

    Full Text Available With the advent of technology and multimedia information, digital images are increasing very quickly. Various techniques are being developed to retrieve/search digital information or data contained in the image. Traditional Text Based Image Retrieval System is not plentiful. Since it is time consuming as it require manual image annotation. Also, the image annotation differs with different peoples. An alternate to this is Content Based Image Retrieval (CBIR system. It retrieves/search for image using its contents rather the text, keywords etc. A lot of exploration has been compassed in the range of Content Based Image Retrieval (CBIR with various feature extraction techniques. Shape is a significant image feature as it reflects the human perception. Moreover, Shape is quite simple to use by the user to define object in an image as compared to other features such as Color, texture etc. Over and above, if applied alone, no descriptor will give fruitful results. Further, by combining it with an improved classifier, one can use the positive features of both the descriptor and classifier. So, a tryout will be made to establish an algorithm for accurate feature (Shape extraction in Content Based Image Retrieval (CBIR. The main objectives of this project are: (a To propose an algorithm for shape feature extraction using CBIR, (b To evaluate the performance of proposed algorithm and (c To compare the proposed algorithm with state of art techniques.

  3. Copy-Move Forgery Detection Technique for Forensic Analysis in Digital Images

    Directory of Open Access Journals (Sweden)

    Toqeer Mahmood

    2016-01-01

    Full Text Available Due to the powerful image editing tools images are open to several manipulations; therefore, their authenticity is becoming questionable especially when images have influential power, for example, in a court of law, news reports, and insurance claims. Image forensic techniques determine the integrity of images by applying various high-tech mechanisms developed in the literature. In this paper, the images are analyzed for a particular type of forgery where a region of an image is copied and pasted onto the same image to create a duplication or to conceal some existing objects. To detect the copy-move forgery attack, images are first divided into overlapping square blocks and DCT components are adopted as the block representations. Due to the high dimensional nature of the feature space, Gaussian RBF kernel PCA is applied to achieve the reduced dimensional feature vector representation that also improved the efficiency during the feature matching. Extensive experiments are performed to evaluate the proposed method in comparison to state of the art. The experimental results reveal that the proposed technique precisely determines the copy-move forgery even when the images are contaminated with blurring, noise, and compression and can effectively detect multiple copy-move forgeries. Hence, the proposed technique provides a computationally efficient and reliable way of copy-move forgery detection that increases the credibility of images in evidence centered applications.

  4. Pressure ulcer image segmentation technique through synthetic frequencies generation and contrast variation using toroidal geometry.

    Science.gov (United States)

    David, Ortiz P; Sierra-Sosa, Daniel; Zapirain, Begoña García

    2017-01-06

    Pressure ulcers have become subject of study in recent years due to the treatment high costs and decreased life quality from patients. These chronic wounds are related to the global life expectancy increment, being the geriatric and physical disable patients the principal affected by this condition. Injuries diagnosis and treatment usually takes weeks or even months by medical personel. Using non-invasive techniques, such as image processing techniques, it is possible to conduct an analysis from ulcers and aid in its diagnosis. This paper proposes a novel technique for image segmentation based on contrast changes by using synthetic frequencies obtained from the grayscale value available in each pixel of the image. These synthetic frequencies are calculated using the model of energy density over an electric field to describe a relation between a constant density and the image amplitude in a pixel. A toroidal geometry is used to decompose the image into different contrast levels by variating the synthetic frequencies. Then, the decomposed image is binarized applying Otsu's threshold allowing for obtaining the contours that describe the contrast variations. Morphological operations are used to obtain the desired segment of the image. The proposed technique is evaluated by synthesizing a Data Base with 51 images of pressure ulcers, provided by the Centre IGURCO. With the segmentation of these pressure ulcer images it is possible to aid in its diagnosis and treatment. To provide evidences of technique performance, digital image correlation was used as a measure, where the segments obtained using the methodology are compared with the real segments. The proposed technique is compared with two benchmarked algorithms. The results over the technique present an average correlation of 0.89 with a variation of ±0.1 and a computational time of 9.04 seconds. The methodology presents better segmentation results than the benchmarked algorithms using less computational time and

  5. Visualization of brain surface structures by weighted summation technique using multislice MR images

    International Nuclear Information System (INIS)

    Machida, Yoshio; Hatanaka, Masahiko; Hagiwara, Masayuki; Sugimoto, Hiroshi; Yoshida, Tadatoki; Katada, Kazuhiro.

    1991-01-01

    Surface anatomy scanning (SAS) technique which visualizes brain surface structures has been developed since 1987. In this paper, we propose a modified method called 'multislice SAS', which also generates such surface structure images, and has several advantages compared with conventional SAS technique. The conventional SAS technique uses a very long echo time sequence (e.g. SE(3000, 250)) with a thick slice and a surface coil to enhance CSF on the brain surface. Our modified technique also uses a long echo time sequence. But, added multislice images, each appropriately weighted, are used in stead of a thick slice and a surface coil. Our basic studies have shown that this modified method has the following advantage: Several surface images with slightly different summation directions are obtained, and they are used for stereographic display and cine display. This is very useful for visualizing the spatial relationship of brain surface structures. By choosing appropriate weighting, we can obtain clinically legible surface images. This technique dose not require a surface coil. It means that flexibility of selecting imaging direction is high. We can make a lot of modifications, because the original multislice images of weighted summation are arbitrary. And we also clarify some limitation or disadvantage of this modified method. In conclusion, we think that this technique is one of the practical approaches for surface anatomy imaging. (author)

  6. Bit Plane Coding based Steganography Technique for JPEG2000 Images and Videos

    Directory of Open Access Journals (Sweden)

    Geeta Kasana

    2016-02-01

    Full Text Available In this paper, a Bit Plane Coding (BPC based steganography technique for JPEG2000 images and Motion JPEG2000 video is proposed. Embedding in this technique is performed in the lowest significant bit planes of the wavelet coefficients of a cover image. In JPEG2000 standard, the number of bit planes of wavelet coefficients to be used in encoding is dependent on the compression rate and are used in Tier-2 process of JPEG2000. In the proposed technique, Tier-1 and Tier-2 processes of JPEG2000 and Motion JPEG2000 are executed twice on the encoder side to collect the information about the lowest bit planes of all code blocks of a cover image, which is utilized in embedding and transmitted to the decoder. After embedding secret data, Optimal Pixel Adjustment Process (OPAP is applied on stego images to enhance its visual quality. Experimental results show that proposed technique provides large embedding capacity and better visual quality of stego images than existing steganography techniques for JPEG2000 compressed images and videos. Extracted secret image is similar to the original secret image.

  7. Experimental study of digital image processing techniques for LANDSAT data

    Science.gov (United States)

    Rifman, S. S. (Principal Investigator); Allendoerfer, W. B.; Caron, R. H.; Pemberton, L. J.; Mckinnon, D. M.; Polanski, G.; Simon, K. W.

    1976-01-01

    The author has identified the following significant results. Results are reported for: (1) subscene registration, (2) full scene rectification and registration, (3) resampling techniques, (4) and ground control point (GCP) extraction. Subscenes (354 pixels x 234 lines) were registered to approximately 1/4 pixel accuracy and evaluated by change detection imagery for three cases: (1) bulk data registration, (2) precision correction of a reference subscene using GCP data, and (3) independently precision processed subscenes. Full scene rectification and registration results were evaluated by using a correlation technique to measure registration errors of 0.3 pixel rms thoughout the full scene. Resampling evaluations of nearest neighbor and TRW cubic convolution processed data included change detection imagery and feature classification. Resampled data were also evaluated for an MSS scene containing specular solar reflections.

  8. Optical Imaging and Microscopy Techniques and Advanced Systems

    CERN Document Server

    Török, Peter

    2007-01-01

    This text on contemporary optical systems is intended for optical researchers and engineers, graduate students and optical microscopists in the biological and biomedical sciences. This second edition contains two completely new chapters. In addition most of the chapters from the first edition have been revised and updated. The book consists of three parts: The first discusses high-aperture optical systems, which form the backbone of optical microscopes. An example is a chapter new in the second edition on the emerging field of high numerical aperture diffractive lenses which seems to have particular promise in improving the correction of lenses. In this part particular attention is paid to optical data storage. The second part is on the use of non-linear optical techniques, including nonlinear optical excitation (total internal reflection fluorescence, second and third harmonic generation and two photon microscopy) and non-linear spectroscopy (CARS). The final part of the book presents miscellaneous technique...

  9. Imaging techniques in the diagnosis of coronary heart disease

    International Nuclear Information System (INIS)

    Frank, H.

    1997-01-01

    Coronary heart disease is the leading cause of death and disability worldwide. Coronary angiography makes it possible to visualize coronary artery stenosis and can be used for angioplasty and stent implantation; however, it does not allow the assessment of changes in myocardial microcirculation. The severity of an angiographically evaluated coronary stenosis does not always correspond to the extent of myocardial ischemia. Nonivasive techniques are needed to reexamine our reliance on coronary angiography and to explore the clinical value fo the physiological assessment of coronary artery stenoses. Such noninvasive techniques might become important tools in the future following an overal evaluation of coronary morphology, myocardial function and perfusion ascertained by all available methods. (orig.) [de

  10. State-of-the-art soft computing techniques in image steganography domain

    Science.gov (United States)

    Hussain, Hanizan Shaker; Din, Roshidi; Samad, Hafiza Abdul; Yaacub, Mohd Hanafizah; Murad, Roslinda; Rukhiyah, A.; Sabdri, Noor Maizatulshima

    2016-08-01

    This paper reviews major works of soft computing (SC) techniques in image steganography and watermarking in the last ten years, focusing on three main SC techniques, which are neural network, genetic algorithm, and fuzzy logic. The findings suggests that all these works applied SC techniques either during pre-processing, embedding or extracting stages or more than one of these stages. Therefore, the presence of SC techniques with their diverse approaches and strengths can help researchers in future work to attain excellent quality of image information hiding that comprises both imperceptibility and robustness.

  11. On the benefit of the negative-spherical-aberration imaging technique for quantitative HRTEM

    International Nuclear Information System (INIS)

    Jia, C.L.; Houben, L.; Thust, A.; Barthel, J.

    2010-01-01

    Employing an aberration corrector in a high-resolution transmission electron microscope, the spherical aberration C S can be tuned to negative values, resulting in a novel imaging technique, which is called the negative C S imaging (NCSI) technique. The image contrast obtained with the NCSI technique is compared quantitatively with the image contrast formed with the traditional positive C S imaging (PCSI) technique. For the case of thin objects negative C S images are superior to positive C S images concerning the magnitude of the obtained contrast, which is due to constructive rather than destructive superposition of fundamental contrast contributions. As a consequence, the image signal obtained with a negative spherical aberration is significantly more robust against noise caused by amorphous surface layers, resulting in a measurement precision of atomic positions which is by a factor of 2-3 better at an identical noise level. The quantitative comparison of the two alternative C S -corrected imaging modes shows that the NCSI mode yields significantly more precise results in quantitative high-resolution transmission electron microscopy of thin objects than the traditional PCSI mode.

  12. Research on the affect of differential-images technique to the resolution of infrared spatial camera

    Science.gov (United States)

    Jin, Guang; An, Yuan; Qi, Yingchun; Hu, Fusheng

    2007-12-01

    The optical system of infrared spatial camera adopts bigger relative aperture and bigger pixel size on focal plane element. These make the system have bulky volume and low resolution. The potential of the optical systems can not be exerted adequately. So, one method for improving resolution of infrared spatial camera based on multi-frame difference-images is introduced in the dissertation. The method uses more than one detectors to acquire several difference images, and then reconstructs a new high-resolution image from these images through the relationship of pixel grey value. The technique of difference-images that uses more than two detectors is researched, and it can improve the resolution 2.5 times in theory. The relationship of pixel grey value between low-resolution difference-images and high-resolution image is found by analyzing the energy of CCD sampling, a general relationship between the enhanced times of the resolution of the detected figure with differential method and the least count of CCD that will be used to detect figure is given. Based on the research of theory, the implementation process of utilizing difference-images technique to improve the resolution of the figure was simulated used Matlab software by taking a personality image as the object, and the software can output the result as an image. The result gotten from the works we have finished proves that the technique is available in high-resolution image reconstruction. The resolution of infrared spatial camera can be improved evidently when holding the size of optical structure or using big size detector by applying for difference image technique. So the technique has a high value in optical remote fields.

  13. DETECTING GLASS SURFACE CORROSION WITH IMAGE PROCESSING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Rafet AKDENİZ

    2012-12-01

    Full Text Available Glass is a kind of amorphous materials that exhibits a transition from rigid to viscous state and finally liquid state when heated. For daily usage, it is desirable to have different forms and differenttransparencies for different purposes. Most widely used one is the one with high transparency and flat surface.One of the detrimental effects that glass is undergone during the storage or usage periods is corrosion. In this work, a way for detecting corrosion on the glass surface by image processing methodis presented.

  14. Performance evaluation of clustering techniques for image segmentation

    Directory of Open Access Journals (Sweden)

    Elmehdi Aitnouri

    2011-02-01

    Full Text Available In this paper, we tackle the performance evaluation of two clustering algorithms: EFC and AIC-based. Both algorithms face the cluster validation problem, in which they need to estimate the number of components. While EFC algorithm is a direct method, the AIC-based is a verificative one. For a fair quantitative evaluation, comparisons are conducted on numerical data and image histograms data are used. We also propose to use artificial data satisfying the overlapping rate between adjacent components. The artificial data is modeled as a mixture of univariate normal densities as they are able to approximate a wide class of continuous densities.

  15. A Partnership Training Program in Breast Cancer Diagnosis: Concept Development of the Next Generation Diagnostic Breast Imaging Using Digital Image Library and Networking Techniques

    National Research Council Canada - National Science Library

    Chouikha, Mohamed F

    2004-01-01

    ...); and Georgetown University (Image Science and Information Systems, ISIS). In this partnership training program, we will train faculty and students in breast cancer imaging, digital image database library techniques and network communication strategy...

  16. An image processing technique for diagnosis of Alzheimer's disease

    Science.gov (United States)

    Mahmoudian, Massoud; Ebrahimi, Soltan Ahmed; Kiani, Zahra

    2009-01-01

    BACKGROUND: Patients with Alzheimer's disease (AD) reportedly exhibit hypersensitivity to much diluted tropicamide solution (0.005%), a M4 muscarinic receptor antagonist. Therefore intraocular application of 0.005% tropicamide may be useful for screening dementia. The aim of this study was to simplify the pupil response test by using a new image analyzing system, which consists of a cheap, simple, and easy to use web-camera and a computer. METHODS: Intraocular tropicamide of 0.005% concentration was administered in 3 groups: Alzheimer's disease patients (n = 8, average age = 76 ± 5), non-Alzheimer's disease elderly (n = 6, average age = 65 ± 7), and young subjects (n = 8, average age = 28 ± 5). Every 5 minutes for 60 minutes, image of the eye's shape were taken, and the diameter of the pupils was measured. RESULTS: The results showed that differences in pupil dilation rate between Alzheimer's disease and non-Alzheimer's disease subjects were statistically significant. ROC analysis showed that after 35 minutes the sensitivity and specificity of the test were 100%. CONCLUSIONS: Based on our results, we concluded that this recording system might be an appropriate and reliable tool for pupil response diagnosis test of Alzheimer's disease. PMID:21772885

  17. Imaging monitoring techniques applications in the transient gratings detection

    Science.gov (United States)

    Zhao, Qing-ming

    2009-07-01

    Experimental studies of Degenerate four-wave mixing (DFWM) in iodine vapor at atmospheric pressure and 0℃ and 25℃ are reported. The Laser-induced grating (LIG) studies are carried out by generating the thermal grating using a pulsed, narrow bandwidth, dye laser .A new image processing system for detecting forward DFWM spectroscopy on iodine vapor is reported. This system is composed of CCD camera, imaging processing card and the related software. With the help of the detecting system, phase matching can be easily achieved in the optical arrangement by crossing the two pumps and the probe as diagonals linking opposite corners of a rectangular box ,and providing a way to position the PhotoMultiplier Tube (PMT) . Also it is practical to know the effect of the pointing stability on the optical path by monitoring facula changing with the laser beam pointing and disturbs of the environment. Finally the effects of Photostability of dye laser on the ration of signal to noise in DFWM using forward geometries have been investigated in iodine vapor. This system makes it feasible that the potential application of FG-DFWM is used as a diagnostic tool in combustion research and environment monitoring.

  18. Visual servoing in medical robotics: a survey. Part II: tomographic imaging modalities--techniques and applications.

    Science.gov (United States)

    Azizian, Mahdi; Najmaei, Nima; Khoshnam, Mahta; Patel, Rajni

    2015-03-01

    Intraoperative application of tomographic imaging techniques provides a means of visual servoing for objects beneath the surface of organs. The focus of this survey is on therapeutic and diagnostic medical applications where tomographic imaging is used in visual servoing. To this end, a comprehensive search of the electronic databases was completed for the period 2000-2013. Existing techniques and products are categorized and studied, based on the imaging modality and their medical applications. This part complements Part I of the survey, which covers visual servoing techniques using endoscopic imaging and direct vision. The main challenges in using visual servoing based on tomographic images have been identified. 'Supervised automation of medical robotics' is found to be a major trend in this field and ultrasound is the most commonly used tomographic modality for visual servoing. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Application of magnetic resonance imaging (MRI) technique on monitoring flower bud differentiation of tulip

    International Nuclear Information System (INIS)

    Han Haojun; Yang Hongguang; Han Hongbin; Sun Xiaomei

    2009-01-01

    Magnetic resonance imaging (MRI) was used for observing morphogenesis process in the living specimen situation of tulip flower buds. Through a comparison of different MRI imaging formation technique (longitudinal relaxation-T1WI, transverse relaxation time weighted imaging-T2WI, proton density weighted imaging-PDWI), seeking for an accurate and practical MRI technique to observe tulip bulb and differentiation period of flower bud. The results showed that in the demonstration of the morphological characters as well as morphogenesis process of flower bud differentiation, the T1WI was completely consistent with the results of rough slice, PDWI and T1WI also had obviously higher map quality than the T2WI (P<0.05). It is indicated that the magnetic resonance imaging technique could monitor the development of flower bud differentiation in vivo. (authors)

  20. Identification of early cancerous lesion of esophagus with endoscopic images by hyperspectral image technique (Conference Presentation)

    Science.gov (United States)

    Huang, Shih-Wei; Chen, Shih-Hua; Chen, Weichung; Wu, I.-Chen; Wu, Ming Tsang; Kuo, Chie-Tong; Wang, Hsiang-Chen

    2016-03-01

    This study presents a method to identify early esophageal cancer within endoscope using hyperspectral imaging technology. The research samples are three kinds of endoscopic images including white light endoscopic, chromoendoscopic, and narrow-band endoscopic images with different stages of pathological changes (normal, dysplasia, dysplasia - esophageal cancer, and esophageal cancer). Research is divided into two parts: first, we analysis the reflectance spectra of endoscopic images with different stages to know the spectral responses by pathological changes. Second, we identified early cancerous lesion of esophagus by principal component analysis (PCA) of the reflectance spectra of endoscopic images. The results of this study show that the identification of early cancerous lesion is possible achieve from three kinds of images. In which the spectral characteristics of NBI endoscopy images of a gray area than those without the existence of the problem the first two, and the trend is very clear. Therefore, if simply to reflect differences in the degree of spectral identification, chromoendoscopic images are suitable samples. The best identification of early esophageal cancer is using the NBI endoscopic images. Based on the results, the use of hyperspectral imaging technology in the early endoscopic esophageal cancer lesion image recognition helps clinicians quickly diagnose. We hope for the future to have a relatively large amount of endoscopic image by establishing a hyperspectral imaging database system developed in this study, so the clinician can take this repository more efficiently preliminary diagnosis.

  1. A rapid compression technique for 4-D functional MRI images using data rearrangement and modified binary array techniques.

    Science.gov (United States)

    Uma Vetri Selvi, G; Nadarajan, R

    2015-12-01

    Compression techniques are vital for efficient storage and fast transfer of medical image data. The existing compression techniques take significant amount of time for performing encoding and decoding and hence the purpose of compression is not fully satisfied. In this paper a rapid 4-D lossy compression method constructed using data rearrangement, wavelet-based contourlet transformation and a modified binary array technique has been proposed for functional magnetic resonance imaging (fMRI) images. In the proposed method, the image slices of fMRI data are rearranged so that the redundant slices form a sequence. The image sequence is then divided into slices and transformed using wavelet-based contourlet transform (WBCT). In WBCT, the high frequency sub-band obtained from wavelet transform is further decomposed into multiple directional sub-bands by directional filter bank to obtain more directional information. The relationship between the coefficients has been changed in WBCT as it has more directions. The differences in parent–child relationships are handled by a repositioning algorithm. The repositioned coefficients are then subjected to quantization. The quantized coefficients are further compressed by modified binary array technique where the most frequently occurring value of a sequence is coded only once. The proposed method has been experimented with fMRI images the results indicated that the processing time of the proposed method is less compared to existing wavelet-based set partitioning in hierarchical trees and set partitioning embedded block coder (SPECK) compression schemes [1]. The proposed method could also yield a better compression performance compared to wavelet-based SPECK coder. The objective results showed that the proposed method could gain good compression ratio in maintaining a peak signal noise ratio value of above 70 for all the experimented sequences. The SSIM value is equal to 1 and the value of CC is greater than 0.9 for all

  2. The new imaging techniques: principles, limitations and the question of cost

    International Nuclear Information System (INIS)

    Marsault, C.; Heran, F.; Brugieres, P.; Le Bras, F.; Castrec-Carpo, A.

    1989-01-01

    The new imaging techniques modify the diagnostic, or even sometimes therapeutic, decision lines. Their efficiency is much greater than that of the old techniques, while pretium doloris and side-effects are considerably reduced. Such advances are not without a major disadvantage: the ever increasing cost of imaging explorations. Radiological guidance (with conventional radiology, ultrasounds and computerized tomography) facilitates percutaneous procedures for diagnostic (biopsy) or therapeutic purposes (emptying of abscesses, chemonucleolysis of herniated lumbar disc, etc.) [fr

  3. Precipitates Segmentation from Scanning Electron Microscope Images through Machine Learning Techniques

    OpenAIRE

    João P. Papa; Clayton R. Pereira; Victor H.C. de Albuquerque; Cleiton C. Silva; Alexandre X. Falcão; João Manuel R. S.Tavares

    2011-01-01

    The presence of precipitates in metallic materials affects its durability, resistance and mechanical properties. Hence, its automatic identification by image processing and machine learning techniques may lead to reliable and efficient assessments on the materials. In this paper, we introduce four widely used supervised pattern recognition techniques to accomplish metallic precipitates segmentation in scanning electron microscope images from dissimilar welding on a Hastelloy C-276 alloy: Supp...

  4. State-of-the-art cranial sonography: Part 1, modern techniques and image interpretation.

    Science.gov (United States)

    Lowe, Lisa H; Bailey, Zachary

    2011-05-01

    In this era of radiation awareness, high-quality ultrasound is more important than ever. Although cranial sonography equipment has advanced greatly, application of modern techniques has not been utilized in a fashion commensurate to other cross-sectional modalities. This article will describe modern cranial sonography techniques, including the utility of linear imaging, use of additional fontanels, and screening Doppler imaging. When modern protocols are used, cranial sonography is highly accurate for the detection of cranial abnormalities.

  5. Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

    Energy Technology Data Exchange (ETDEWEB)

    Alfeld, Matthias, E-mail: matthias.alfeld@desy.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany); University of Antwerp, Department of Chemistry, Groenenbrogerlaan 171, B-2020 Antwerp (Belgium); Broekaert, José A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany)

    2013-10-01

    Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. - Highlights: • All mobile sub-surface and depth-profiling techniques for paintings are reviewed. • The number of techniques available has increased considerably in the last years. • X-ray radiography and infrared reflectography are still the most used techniques. • Scanning macro-XRF and optical coherence tomography begin to establish. • Industrial non destructive testing techniques support the preservation of paintings.

  6. Two-dimensional gel electrophoresis image registration using block-matching techniques and deformation models.

    Science.gov (United States)

    Rodriguez, Alvaro; Fernandez-Lozano, Carlos; Dorado, Julian; Rabuñal, Juan R

    2014-06-01

    Block-matching techniques have been widely used in the task of estimating displacement in medical images, and they represent the best approach in scenes with deformable structures such as tissues, fluids, and gels. In this article, a new iterative block-matching technique-based on successive deformation, search, fitting, filtering, and interpolation stages-is proposed to measure elastic displacements in two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) images. The proposed technique uses different deformation models in the task of correlating proteins in real 2D electrophoresis gel images, obtaining an accuracy of 96.6% and improving the results obtained with other techniques. This technique represents a general solution, being easy to adapt to different 2D deformable cases and providing an experimental reference for block-matching algorithms. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Reliability and comparison of acromion assessment techniques on x-ray and magnetic resonance imaging (reliability of acromion assessment techniques)

    International Nuclear Information System (INIS)

    Viskontas, D.G.; MacDermid, J.C.; Drosdowech, D.S.; Garvin, G.J.; Romano, W.M.; Faber, K.J.

    2005-01-01

    To determine the reliability and correlation of plain radiography and magnetic resonance imaging (MRI) in the assessment of acromion morphology. Materials and Methods: Acromion morphology was assessed using the lateral acromion angle (LAA) and the acromion-humeral interval (AHI). Thirty patients who had x-rays and MRI for impingement syndrome were included. Six blinded observers assessed the acromion morphology subjectively and objectively. Results: Neither acromion assessment technique demonstrated a positive correlation (kappa and intraclass coefficient 0.55) when measured objectively by experienced observers. Conclusion: The LAA and the AHI are both reliable acromion assessment techniques on X-ray and MRI when measured objectively and by experienced observers. (author)

  8. Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images.

    Science.gov (United States)

    Gandhamal, Akash; Talbar, Sanjay; Gajre, Suhas; Hani, Ahmad Fadzil M; Kumar, Dileep

    2017-04-01

    Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. New Image-Based Techniques for Prostate Biopsy and Treatment

    Science.gov (United States)

    2012-04-01

    Sal - cudean, “Brachytherapy seed reconstruction with joint-encoded C-arm single-axis rotation and motion compensation,”Med. Image Anal., vol. 15, no. 5...VN1 VNM 2 66664 3 77775; ðA:12Þ A21 ¼ ðA12Þ0; ðA:13Þ b1 ¼ XM j¼1 V1jqj .. . VNjqj 2 664 3 775 0 BB@ 1 CCA ; ðA:14Þ b2 ¼ XN i¼1 Vi1q1 .. . ViMqM...2 664 3 775 0 BB@ 1 CCA : ðA:15Þ At this point, the set of linear equations in (A.6) is under-deter- mined and the matrix A in (A.8) is singular

  10. Fall detection for multiple pedestrians using depth image processing technique.

    Science.gov (United States)

    Yang, Shih-Wei; Lin, Shir-Kuan

    2014-04-01

    A fall detection method based on depth image analysis is proposed in this paper. As different from the conventional methods, if the pedestrians are partially overlapped or partially occluded, the proposed method is still able to detect fall events and has the following advantages: (1) single or multiple pedestrian detection; (2) recognition of human and non-human objects; (3) compensation for illumination, which is applicable in scenarios using indoor light sources of different colors; (4) using the central line of a human silhouette to obtain the pedestrian tilt angle; and (5) avoiding misrecognition of a squat or stoop as a fall. According to the experimental results, the precision of the proposed fall detection method is 94.31% and the recall is 85.57%. The proposed method is verified to be robust and specifically suitable for applying in family homes, corridors and other public places. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Technique of obstetric pelvimetry by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Sigmund, G.; Wenz, W.; Bauer, M.; DeGregorio, G.; Henne, K.

    1991-01-01

    Magnetic resonance imaging (MRL) allows for the first time direct determination of maternal pelvic dimensions without ionising radiation. Phantom measurements and the correlation with traditional pelvimetric measurements in 10 patients after Caesarean section have shown mean differences of ± 2 mm, with a maximum of 5 mm. The evaluation of pelvic configuration is obtained analogous to the conventional roentgenogram. In addition to conventional or digital X-ray pelvimetry, the soft tissues of the maternal pelvis and the presenting part of the foetus is delineated with high contrast. Positioning in the body coil can be accomplished even late in pregnancy or in impending labour, acceptance by the pregnant women being high. Whereas in a given indication after delivery conventional X-ray pelvimetry continues to be performed, antenatally MRI pelvimetry has now been established in our Departments as the method of choice - based on meanwhile 107 examinations. Present drawbacks are the relatively high cost and the limited availability of MR units. (orig.) [de

  12. Magnetic resonance imaging of breast. Actual technique and indications

    International Nuclear Information System (INIS)

    Tardivon, Anne

    2007-01-01

    Optimal breast MRI protocols are required using dedicated breast coils, high spatial resolution dynamic sequences (morphologic criteria are significantly more accurate than kinetic criteria) and bolus injection of contrast medium. Any abnormal MR enhancement must be described using BI-RADSMRI lexicon. Main indications of breast MRI are: suspicion of intra-capsular rupture (silicone implants), local relapse in a treated breast, search for breast cancer (metastatic axillary lymph nodes), locals staging of a breast cancer (dense breasts), follow-up of cancer under neoadjuvant chemotherapy, and screening in high-risk patients (gene mutation background). MRI is also useful for patients with unresolved problems at standard imaging (high negative predictive value of MRI). In patients with breast cancer, it is important to underline the need for radiologists to work with the multidisciplinary team and the ability to perform MR-guided biopsies for additional suspicious enhancements. (author) [es

  13. Analysis of Proposed Noise Detection & Removal Technique in Degraded Fingerprint Images

    Science.gov (United States)

    Hamid, Ainul Azura Abdul; Rahim, Mohd Shafry Mohd; Al-Mazyad, Abdulaziz S.; Saba, Tanzila

    2015-12-01

    The quality of fingerprint images is important to ensure good performance of fingerprint recognition since recognition process depends heavily on the quality of fingerprint images. Fingerprint images obtained from the acquisition phase are either contaminated with noise or degraded due to poor quality machines. Several factors such as scars, moist in scanner and many more noises affect the quality of the images during scanning process. This paper performed an analysis and compared noise removal techniques reported in the literature for fingerprint images. We also implemented histogram equalization, median filter, Fourier transform, unsharp mask and grayscale enhancement techniques. The quality of enhanced images is measured by peak signal to noise ratio (PSNR) calculation for analysis and comparisons.

  14. Applicability of TOD, MTDP, MRT and DMRT for dynamic image enhancement techniques

    NARCIS (Netherlands)

    Bijl, P.; Schutte, K.; Hogervorst, M.A.

    2006-01-01

    Current end-to-end sensor performance measures such as the TOD, MRT, DMRT and MTDP were developed to describe Target Acquisition performance for static imaging. Recent developments in sensor technology (e.g. microscan) and image enhancement techniques (e.g. Super Resolution and Scene-Based

  15. [Principles and applications of hyperspectral imaging technique in quality and safety inspection of fruits and vegetables].

    Science.gov (United States)

    Zhang, Bao-Hua; Li, Jiang-Bo; Fan, Shu-Xiang; Huang, Wen-Qian; Zhang, Chi; Wang Qing-Yan; Xiao, Guang-Dong

    2014-10-01

    The quality and safety of fruits and vegetables are the most concerns of consumers. Chemical analytical methods are traditional inspection methods which are time-consuming and labor intensive destructive inspection techniques. With the rapid development of imaging technique and spectral technique, hyperspectral imaging technique has been widely used in the nondestructive inspection of quality and safety of fruits and vegetables. Hyperspectral imaging integrates the advantages of traditional imaging and spectroscopy. It can obtain both spatial and spectral information of inspected objects. Therefore, it can be used in either external quality inspection as traditional imaging system, or internal quality or safety inspection as spectroscopy. In recent years, many research papers about the nondestructive inspection of quality and safety of fruits and vegetables by using hyperspectral imaging have been published, and in order to introduce the principles of nondestructive inspection and track the latest research development of hyperspectral imaging in the nondestructive inspection of quality and safety of fruits and vegetables, this paper reviews the principles, developments and applications of hyperspectral imaging in the external quality, internal quality and safety inspection of fruits and vegetables. Additionally, the basic components, analytical methods, future trends and challenges are also reported or discussed in this paper.

  16. Comment on ‘A technique for image encryption using digital signature’

    Science.gov (United States)

    Hernández Encinas, L.; Peinado Domínguez, A.

    2006-12-01

    The security of a recently proposed technique for encryption images by Sinha and Singh [A. Sinha, K. Singh, Opt. Commun. 218 (2003) 229], based on the use of digital signatures and error correcting codes, is analyzed. The proposed cryptosystem is shown to have some weakness. In fact, the secret key and the original image can be recovered efficiently by a brute force attack.

  17. Reflexions about imaging technique and examination protocol 2. MR-examination protocol

    International Nuclear Information System (INIS)

    Wichmann, Werner

    2004-01-01

    Adequate imaging protocol is crucial for any imaging technique. As MR is a time consuming examination, the physician serves the patient best, when he/she makes the best choice of sequences, which answer the question of the clinician and provide a definite diagnosis. Although any patient requires an individual protocol, some general rules should be known

  18. Exploiting Measurement Uncertainty Estimation in Evaluation of GOES-R ABI Image Navigation Accuracy Using Image Registration Techniques

    Science.gov (United States)

    Haas, Evan; DeLuccia, Frank

    2016-01-01

    In evaluating GOES-R Advanced Baseline Imager (ABI) image navigation quality, upsampled sub-images of ABI images are translated against downsampled Landsat 8 images of localized, high contrast earth scenes to determine the translations in the East-West and North-South directions that provide maximum correlation. The native Landsat resolution is much finer than that of ABI, and Landsat navigation accuracy is much better than ABI required navigation accuracy and expected performance. Therefore, Landsat images are considered to provide ground truth for comparison with ABI images, and the translations of ABI sub-images that produce maximum correlation with Landsat localized images are interpreted as ABI navigation errors. The measured local navigation errors from registration of numerous sub-images with the Landsat images are averaged to provide a statistically reliable measurement of the overall navigation error of the ABI image. The dispersion of the local navigation errors is also of great interest, since ABI navigation requirements are specified as bounds on the 99.73rd percentile of the magnitudes of per pixel navigation errors. However, the measurement uncertainty inherent in the use of image registration techniques tends to broaden the dispersion in measured local navigation errors, masking the true navigation performance of the ABI system. We have devised a novel and simple method for estimating the magnitude of the measurement uncertainty in registration error for any pair of images of the same earth scene. We use these measurement uncertainty estimates to filter out the higher quality measurements of local navigation error for inclusion in statistics. In so doing, we substantially reduce the dispersion in measured local navigation errors, thereby better approximating the true navigation performance of the ABI system.

  19. Subsurface and through-wall SAR imaging techniques for ground penetrating radar

    Directory of Open Access Journals (Sweden)

    Unal M.

    2013-12-01

    Full Text Available This paper presents some useful signal processing and synthetic aperture radar imaging techniques for ultra-wide band (UWB ground penetrating radar. Novel UWB antenna structures are experimentally designed in this work. Raw and processed data collected in the course of experimental studies of subsurface sensing and through-wall imaging scenarios are demonstrated in B-scan and C-scan target images.

  20. Metal Artifact Suppression in Dental Cone Beam Computed Tomography Images Using Image Processing Techniques.

    Science.gov (United States)

    Johari, Masoumeh; Abdollahzadeh, Milad; Esmaeili, Farzad; Sakhamanesh, Vahideh

    2018-01-01

    Dental cone beam computed tomography (CBCT) images suffer from severe metal artifacts. These artifacts degrade the quality of acquired image and in some cases make it unsuitable to use. Streaking artifacts and cavities around teeth are the main reason of degradation. In this article, we have proposed a new artifact reduction algorithm which has three parallel components. The first component extracts teeth based on the modeling of image histogram with a Gaussian mixture model. Striking artifact reduction component reduces artifacts using converting image into the polar domain and applying morphological filtering. The third component fills cavities through a simple but effective morphological filtering operation. Finally, results of these three components are combined into a fusion step to create a visually good image which is more compatible to human visual system. Results show that the proposed algorithm reduces artifacts of dental CBCT images and produces clean images.

  1. Image quality assessment of single-shot turbo spin echo diffusion-weighted imaging with parallel imaging technique: a phantom study.

    Science.gov (United States)

    Yoshida, Tsukasa; Urikura, Atsushi; Shirata, Kensei; Nakaya, Yoshihiro; Terashima, Shingo; Hosokawa, Yoichiro

    2016-09-01

    This study aimed to evaluate the image quality and apparent diffusion coefficient (ADC) values of single-shot turbo spin echo (TSE) diffusion-weighted (DW) images obtained using a parallel imaging (PI) technique. All measurements were performed on a 3.0-T whole-body MRI system and 32-channel phased-array coil. Signal-to-noise ratio (SNR) and ADC values were measured with a DW imaging (DWI) phantom comprising granulated sugar and agar. The SNRs were calculated using a subtraction method and compared among TSE-DW images at acceleration factors (AFs) of 1-4. Image blur was visually assessed on TSE-DW images of a pin phantom at AFs of 1-4. The ADC values were calculated using DW images with b = 0 and 1000 s mm(-2). The ADC values of TSE-DW images and echo-planar imaging EPI-DW images were compared. The SNRs decreased as AFs increased, despite selecting the shortest echo time. A lower AF caused increased image blur in the phase-encoding direction. The ADC values of TSE-DWI tended to be lower than those of EPI-DWI, and AFs of 3 and 4 yielded variable ADC values on TSE-DW images. TSE-DWI with an AF of 3 or 4 yielded reduced SNRs; in addition, the image noise and artefacts associated with PI technique may have affected ADC measurements, despite improving image blur in the phase-encoding direction. Optimizing the imaging parameters of TSE-DWI is useful for providing good image quality and accurate ADC measurements.

  2. Radiation protection in newer medical imaging techniques: Cardiac CT

    International Nuclear Information System (INIS)

    2008-01-01

    Medical imaging has seen many developments as it has evolved since the mid-1890s. In the last 30-40 years, the pace of innovation has increased, starting with the introduction of computed tomography (CT) in the early 1970s. During the last decade, the rate of change has accelerated further, in terms of continuing innovation and its global application. Most patient exposure now arises from practices that barely existed two decades ago. These developments are evident in the technology on which this volume is based - multislice/detector CT scanning and its application in cardiac imaging. However, this advance is achieved at the cost of a radiation burden to the individual patient, and possibly to the community, if its screening potential is exploited. Much effort will be required to ensure that the undoubted benefit of this new practice will not pose an undue level of detriment to the individual in multiple examinations. For practitioners and regulators, it is evident that innovation has been driven by both the imaging industry and an increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practices lag (inevitably) behind the industrial and clinical innovations. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill this growing vacuum, by bringing up to date and timely advice from experienced practitioners to bear on the problems involved. The advice in this report has been developed as part of the IAEA's statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for the worldwide application of these standards. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) were issued by the IAEA and co-sponsored by organizations including the Food and Agriculture

  3. Calibration technique for monoplane stereo x-ray system in imaging guidance

    Science.gov (United States)

    Jiang, Hang-yi; Liu, Hong; Chen, Wei R.

    2000-05-01

    A simple calibration technique for monoplane stereo x-ray imaging system in stereotactic breast biopsy was developed. According to the principle of perspective projection, a monoplane stereo imaging model was established, the geometric parameters for the purpose of 3D point reconstruction were described. The parameters are source- imager-distance and the x-ray tube positions with respect to the imaging receptor. These parameters are calculated using a phantom consisting of three radio-opaque calibration lines of known length and orientation in 3D space and applying the concepts of similar triangles. Two line segments are parallel to the image detector and another one is perpendicular to the image detector. The computer simulations and experiments were carried out which determines these parameters for our CCD based monoplane stereotactic prototype. The results were in agreement with the theoretical prediction. This calibration technique is applied to the stereo imaging system where the final calibration error is within 1.5 percent. The method is simple and reliable. One promising application of this technique for the calibration lies in digital mammography imaging guidance, but applications in other forms of radiographic imaging are possible also.

  4. Rapid musculoskeletal magnetic resonance imaging using integrated parallel acquisition techniques (IPAT) - Initial experiences

    International Nuclear Information System (INIS)

    Romaneehsen, B.; Oberholzer, K.; Kreitner, K.-F.; Mueller, L.P.

    2003-01-01

    Purpose: To investigate the feasibility of using multiple receiver coil elements for time saving integrated parallel imaging techniques (iPAT) in traumatic musculoskeletal disorders. Material and methods: 6 patients with traumatic derangements of the knee, ankle and hip underwent MR imaging at 1.5 T. For signal detection of the knee and ankle, we used a 6-channel body array coil that was placed around the joints, for hip imaging two 4-channel body array coils and two elements of the spine array coil were combined for signal detection. All patients were investigated with a standard imaging protocol that mainly consisted of different turbo spin-echo sequences (PD-, T 2 -weighted TSE with and without fat suppression, STIR). All sequences were repeated with an integrated parallel acquisition technique (iPAT) using a modified sensitivity encoding (mSENSE) technique with an acceleration factor of 2. Overall image quality was subjectively assessed using a five-point scale as well as the ability for detection of pathologic findings. Results: Regarding overall image quality, there were no significant differences between standard imaging and imaging using mSENSE. All pathologies (occult fracture, meniscal tear, torn and interpositioned Hoffa's cleft, cartilage damage) were detected by both techniques. iPAT led to a 48% reduction of acquisition time compared with standard technique. Additionally, time savings with iPAT led to a decrease of pain-induced motion artifacts in two cases. Conclusion: In times of increasing cost pressure, iPAT using multiple coil elements seems to be an efficient and economic tool for fast musculoskeletal imaging with diagnostic performance comparable to conventional techniques. (orig.) [de

  5. Optimization of spatial frequency domain imaging technique for estimating optical properties of food and biological materials

    Science.gov (United States)

    Spatial frequency domain imaging technique has recently been developed for determination of the optical properties of food and biological materials. However, accurate estimation of the optical property parameters by the technique is challenging due to measurement errors associated with signal acquis...

  6. MR imaging of the knee : Three-dimensional fourier transform GRASS technique

    International Nuclear Information System (INIS)

    Kim, Dong Joo; Lee, Young Uk; Youn, Eun Kyung; No, In Gye; Chin, Seoung Bum; Kim, Joon Sik; Choi, Jae Yeul

    1996-01-01

    To evaluate the usefulness of three-dimensional(3D) Fourier transform(FT) gradient refocused acquisition in steady state (GRASS) technique for MR imaging of the knee. Sixty-three knees in 61 patients were imaged on the 1.5T MR system. We compared 3DFT GRASS technique with 2D spin echo(SE) technique in terms of conspicuousness of the lesions of internal knee structures based on the results of arthroscopy or open surgery. As a SE technique, sagittal T1-and T2-weighted, and coronal fat-suppressed T2-weighted sequences were performed using 3D GRASS technique, and we also evaluated arbitrarily reformatted images produced from the original axial voxel images. For the depiction of the tear, 3DFT GRASS was superior to 2D SE in three cases of medial meniscus, one of lateral meniscus, and two of anterior cruciate ligament. Specificity of 3D GRASS was also higher than that of 2D SE in evaluation of lateral meniscus and anterior cruiciate ligament. There was no significant difference in MR diagnosis for tears of the posterior cruciate, medial collateral, and lateral collateral ligaments. 3D GRASS was superior in evaluating the extent and morphology of the torn menisci. The 3DFT GRASS technique was comparable or even superior to the 2D SE technique in the evaluation of the internal structure of the knee, and can be expected to supplement standard MR knee techniques, especially in complicated cases of meniscal or ligamentous tears

  7. Sediment tolerance mechanisms identified in sponges using advanced imaging techniques

    Directory of Open Access Journals (Sweden)

    Brian W. Strehlow

    2017-11-01

    Full Text Available Terrestrial runoff, resuspension events and dredging can affect filter-feeding sponges by elevating the concentration of suspended sediments, reducing light intensity, and smothering sponges with sediments. To investigate how sponges respond to pressures associated with increased sediment loads, the abundant and widely distributed Indo-Pacific species Ianthella basta was exposed to elevated suspended sediment concentrations, sediment deposition, and light attenuation for 48 h (acute exposure and 4 weeks (chronic exposure. In order to visualise the response mechanisms, sponge tissue was examined by 3D X-ray microscopy and scanning electron microscopy (SEM. Acute exposures resulted in sediment rapidly accumulating in the aquiferous system of I. basta, although this sediment was fully removed within three days. Sediment removal took longer (>2 weeks following chronic exposures, and I. basta also exhibited tissue regression and a smaller aquiferous system. The application of advanced imaging approaches revealed that I. basta employs a multilevel system for sediment rejection and elimination, containing both active and passive components. Sponges responded to sediment stress through (i mucus production, (ii exclusion of particles by incurrent pores, (iii closure of oscula and pumping cessation, (iv expulsion of particles from the aquiferous system, and (v tissue regression to reduce the volume of the aquiferous system, thereby entering a dormant state. These mechanisms would result in tolerance and resilience to exposure to variable and high sediment loads associated with both anthropogenic impacts like dredging programs and natural pressures like flood events.

  8. Current cardiac imaging techniques for detection of left ventricular mass

    Directory of Open Access Journals (Sweden)

    Celebi Aksuyek S

    2010-06-01

    Full Text Available Abstract Estimation of left ventricular (LV mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR and cardiovascular computed tomography (CCT are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test.

  9. Water extraction technique in mountainous areas from satellite images

    Science.gov (United States)

    Kaplan, Gordana; Avdan, Ugur

    2017-10-01

    Water monitoring is an important part of water resource management and has become an essential aspect of remote sensing. A number of indices have been developed for water extraction using satellite images. Even though all indices can extract the extent of a water body, none can do so without including a noise component, such as topographic shadows, cloud shadows, snow, ice, and buildup areas, all of which have spectrally similar characteristics under certain circumstances. In order to select the best index for water body extraction, several water indices have been compared. This paper proposes a method for extracting water bodies called the water extraction surface temperature index (WESTI). This method uses normalized difference water index (NDWI) and land surface temperature to eliminate the noise components, especially in mountainous and cold areas where other indices have very low accuracy. The results have shown that WESTI improves the NDWI results by removing more than 80% of topographic shadows, with an overall accuracy of 99% in all cases.

  10. DYNAMIC MAGNETIC RESONANCE IMAGING: PRELIMINARY PRESENTATION OF A TECHNIQUE

    Directory of Open Access Journals (Sweden)

    BRUNO DA COSTA ANCHESCHI

    Full Text Available ABSTRACT Objective: To evaluate morphometric variations of the cervical spine in patients with cervical spondylotic myelopathy (CSM using dynamic magnetic resonance imaging (MRI in neutral, flexion and extension positions. Methods: This is a prospective study of patients with CSM secondary to degenerative disease of the cervical spine. The morphometric parameters were evaluated using T2-weighted MRI sequences in the sagittal plane in neutral, flexion and extension position of the neck. The parameters studied were the anterior length of the spinal cord (ALSC, the posterior length of the spinal cord (PLSC, the diameter of the vertebral canal (DVC and the diameter of the spinal cord (DSC. Results: The ALSC and PLSC were longer in flexion than in extension and neutral position, with statistically significant difference between the flexion and extension position. The DVC and the DSC were greater in flexion than in extension and neutral position, however, there was no statistically significant difference when they were compared in the neutral, flexion and extension positions. Conclusion: Dynamic MRI allows to evaluate morphometric variations in the cervical spinal canal in patients with cervical spondylotic myelopathy.

  11. Hyperspectral imaging based techniques applied to polluted clay characterization

    Science.gov (United States)

    Bonifazi, Giuseppe; Serranti, Silvia

    2006-10-01

    Polluted soils analysis and characterization is one of the basic step to perform in order to collect all the information to design and set-up correct soil reclamation strategies. Soil analysis is usually performed through "in-situ" sampling and laboratory analysis. Such an approach is usually quite expensive and does not allow to reach a direct and detailed knowledge of large areas for the intrinsic limits (high costs) linked to direct sampling and polluting elements detection. As a consequence numerical strategies are applied to extrapolate, starting from a discrete set of data, that is those related to collected samples, information about the contamination level of areas not directly interested by physical sampling. These models are usually very difficult to handle both for the intrinsic variability characterizing the media (soils) and for the high level of interactions between polluting agents, soil characteristics (organic matter content, size class distribution of the inorganic fraction, composition, etc.) and environmental conditions (temperature, humidity, presence of vegetation, human activities, etc.). Aim of this study, starting from previous researches addressed to evaluate the potentialities of hyperspectral imaging approach in polluting soil characterization, was to evaluate the results obtainable in the investigation of an "ad hoc" polluted benthonic clay, usually utilized in rubbish dump, in order to define fast and reliable control strategies addressed to monitor the status of such a material in terms of insulation.

  12. Watermarking Techniques Using Least Significant Bit Algorithm for Digital Image Security Standard Solution- Based Android

    Directory of Open Access Journals (Sweden)

    Ari Muzakir

    2017-05-01

    Full Text Available Ease of deployment of digital image through the internet has positive and negative sides, especially for owners of the original digital image. The positive side of the ease of rapid deployment is the owner of that image deploys digital image files to various sites in the world address. While the downside is that if there is no copyright that serves as protector of the image it will be very easily recognized ownership by other parties. Watermarking is one solution to protect the copyright and know the results of the digital image. With Digital Image Watermarking, copyright resulting digital image will be protected through the insertion of additional information such as owner information and the authenticity of the digital image. The least significant bit (LSB is one of the algorithm is simple and easy to understand. The results of the simulations carried out using android smartphone shows that the LSB watermarking technique is not able to be seen by naked human eye, meaning there is no significant difference in the image of the original files with images that have been inserted watermarking. The resulting image has dimensions of 640x480 with a bit depth of 32 bits. In addition, to determine the function of the ability of the device (smartphone in processing the image using this application used black box testing. 

  13. Application of digital image processing techniques to faint solar flare phenomena

    Science.gov (United States)

    Glackin, D. L.; Martin, S. F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature.

  14. Application of digital image processing techniques to faint solar flare phenomena

    International Nuclear Information System (INIS)

    Glackin, D.L.; Martin, S.F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature

  15. Line-Scan Hyperspectral Imaging Techniques for Food Safety and Quality Applications

    Directory of Open Access Journals (Sweden)

    Jianwei Qin

    2017-01-01

    Full Text Available Hyperspectral imaging technologies in the food and agricultural area have been evolving rapidly over the past 15 years owing to tremendous interest from both academic and industrial fields. Line-scan hyperspectral imaging is a major method that has been intensively researched and developed using different physical principles (e.g., reflectance, transmittance, fluorescence, Raman, and spatially resolved spectroscopy and wavelength regions (e.g., visible (VIS, near infrared (NIR, and short-wavelength infrared (SWIR. Line-scan hyperspectral imaging systems are mainly developed and used for surface inspection of food and agricultural products using area or line light sources. Some of these systems can also be configured to conduct spatially resolved spectroscopy measurements for internal or subsurface food inspection using point light sources. This paper reviews line-scan hyperspectral imaging techniques, with introduction, demonstration, and summarization of existing and emerging techniques for food and agricultural applications. The main topics include related spectroscopy techniques, line-scan measurement methods, hardware components and systems, system calibration methods, and spectral and image analysis techniques. Applications in food safety and quality are also presented to reveal current practices and future trends of line-scan hyperspectral imaging techniques.

  16. Head and neck computed tomography virtual endoscopy: evaluation of a new imaging technique.

    Science.gov (United States)

    Gallivan, R P; Nguyen, T H; Armstrong, W B

    1999-10-01

    To evaluate a new radiographic imaging technique: computed tomography virtual endoscopy (CTVE) for head and neck tumors. Twenty-one patients presenting with head and neck masses who underwent axial computed tomography (CT) scan with contrast were evaluated by CTVE. Comparisons were made with video-recorded images and operative records to evaluate the potential utility of this new imaging technique. Twenty-one patients with aerodigestive head and neck tumors were evaluated by CTVE. One patient had a nasal cylindrical cell papilloma; the remainder, squamous cell carcinomas distributed throughout the upper aerodigestive tract. Patients underwent complete head and neck examination, flexible laryngoscopy, axial CT with contrast, CTVE, and in most cases, operative endoscopy. Available clinical and radiographic evaluations were compared and correlated to CTVE findings. CTVE accurately demonstrated abnormalities caused by intraluminal tumor, but where there was apposition of normal tissue against tumor, inaccurate depictions of surface contour occurred. Contour resolution was limited, and mucosal irregularity could not be defined. There was very good overall correlation between virtual images, flexible laryngoscopic findings, rigid endoscopy, and operative evaluation in cases where oncological resections were performed. CTVE appears to be most accurate in evaluation of subglottic and nasopharyngeal anatomy in our series of patients. CTVE is a new radiographic technique that provides surface-contour details. The technique is undergoing rapid technical evolution, and although the image quality is limited in situations where there is apposition of tissue folds, there are a number of potential applications for this new imaging technique.

  17. Evaluation of New Ultrasound Techniques for Clinical Imaging in selected Liver and Vascular Applications

    DEFF Research Database (Denmark)

    Brandt, Andreas Hjelm

    of data transformation, thus enabling wireless transmission, THI can improve resolution and image contrast, and creates fewer artifacts. Thirty-one patients with verified liver tumors were scanned and recordings with and without visible pathology were performed. Subsequently, eight radiologists evaluated...... new ultrasonic methods for future clinical use. Study I compares two B-mode ultrasound methods: the new experimental technique Synthetic Aperture Sequential Beamforming combined with Tissue Harmonic Imaging (SASB-THI), and a conventional technique combined with THI. While SASB reduces the amount...... that the techniques can be used in the clinic and probably will be part of everyday practice in the near future....

  18. Review of Synthetically Focused Guided Wave Imaging Techniques With Application to Defect Sizing

    Science.gov (United States)

    Davies, J.; Simonetti, F.; Lowe, M.; Cawley, P.

    2006-03-01

    Synthetically focused imaging has been used for some time in the NDE community. The techniques have primarily been directed towards imaging using bulk waves. There has recently been use of SAFT (Synthetic Aperture Focusing Technique) using guided waves in plates. Here, we review three different synthetically focused imaging algorithms for a linear array aperture: CSM (Common Source Method), SAFT and TFM (Total Focusing Method). The resolution of the different techniques is obtained from scalar diffraction theory and then validated by means of a low frequency (50kHz) steel plate experiment using PZT excitation and laser reception of the A0 mode. Imaging of through thickness slits parallel to the array is then discussed.

  19. MCNP simulations of a new time-resolved Compton scattering imaging technique

    International Nuclear Information System (INIS)

    Ilan, Y.

    2004-01-01

    Medical images of human tissue can be produced using Computed Tomography (CT), Positron Emission Tomography (PET), Ultrasound or Magnetic Resonance Imaging (MRI). In all of the above techniques, in order to get a three-dimensional (3D) image, one has to rotate or move the source, the detectors or the scanned target. This procedure is complicated, time consuming and increases the cost and weight of the scanning equipment. Time resolved optical tomography has been suggested as an alternative to the above conventional methods. This technique implies near infrared light (NIR) and fast time-resolved detectors to obtain a 3D image of the scanned target. However, due to the limited penetration of the NIR light in the tissue, the application of this technique is limited to soft tissue like a female breast or a premature infant brain

  20. Technique for verifying treatment fields using portal images with diagnostic quality.

    Science.gov (United States)

    Shiu, A S; Hogstrom, K R; Janjan, N A; Fields, R S; Peters, L J

    1987-10-01

    The image quality of portal films for megavoltage photon beams, when using the double-exposure technique, is poor compared to diagnostic quality, X ray images. A technique is described to record on a single film a megavoltage portal image superimposed upon a diagnostic X ray image, which provides the radiotherapist with "diagnostic quality" portal images. The technique uses a commercially available X ray tube mounted on the head of a 60Co unit. The alignment procedure, which uses a leveling device to ensure that the X ray focal spot and 60Co source are at the same location for each exposure, is confirmed by registering on film the image of an alignment marker. An evaluation of film-screen combination showed therapy verification film in a rare earth intensifying screen cassette to be best suited for this technique. The relationship between off-axis dose and the penumbral region of the portal image has been evaluated and should be useful in the interpretation of portal verification film relative to the treatment volume.

  1. MR imaging of the anterior cruciate ligament. Value of thin slice direct oblique coronal technique

    Energy Technology Data Exchange (ETDEWEB)

    Katahira, Kazuhiro; Yamashita, Yasuyuki; Takahashi, Mutsumasa [Kumamoto Univ. (Japan). School of Medicine; Otsuka, Nobuko; Koga, Yukunori; Fukumoto, Tetsuya; Nomura, Kazutoshi

    2001-02-01

    The value of the thin slice direct oblique coronal technique, which is parallel to the anterior cruciate ligament (ACL), was assessed in the evaluation of ACL injury in comparison with conventional oblique sagittal and coronal images. A thin slice direct oblique coronal technique was developed and applied clinically to 62 patients after conventional oblique sagittal and coronal images had been obtained. MR images of these 62 patients (24 with tears and 38 without tears) with an arthroscopic correlation were evaluated by three radiologists who were unaware of the arthroscopic results. The diagnostic accuracy of these new images was compared with that of oblique sagittal and coronal images by ROC analysis. Conventional oblique sagittal and coronal images for the diagnosis of ACL tears revealed accuracies of 82%, 84%, and 84%, sensitivities of 92%, 92%, and 96% and specificities of 76%, 79%, and 76% for the three reviewers, respectively. On thin slice direct oblique coronal images, specificities of 97%, 97%, and 97%, sensitivities of 96%, 96%, and 96%, and accuracies of 97%, 97%, and 97% were obtained, respectively. Diagnostic ability was significantly better with direct oblique coronal images (mean area under the ROC curve [Az]=0.99) than with conventional oblique sagittal and coronal images (Az=0.91) (p<0.05). The addition of thin slice direct oblique coronal images significantly improved specificity and accuracy in the diagnosis of ACL tears. (author)

  2. Image processing techniques for thermal, x-rays and nuclear radiations

    International Nuclear Information System (INIS)

    Chadda, V.K.

    1998-01-01

    The paper describes image acquisition techniques for the non-visible range of electromagnetic spectrum especially thermal, x-rays and nuclear radiations. Thermal imaging systems are valuable tools used for applications ranging from PCB inspection, hot spot studies, fire identification, satellite imaging to defense applications. Penetrating radiations like x-rays and gamma rays are used in NDT, baggage inspection, CAT scan, cardiology, radiography, nuclear medicine etc. Neutron radiography compliments conventional x-rays and gamma radiography. For these applications, image processing and computed tomography are employed for 2-D and 3-D image interpretation respectively. The paper also covers main features of image processing systems for quantitative evaluation of gray level and binary images. (author)

  3. Innovative techniques, sensors, and approaches for imaging biofilms at different scales.

    Science.gov (United States)

    Neu, Thomas R; Lawrence, John R

    2015-04-01

    Confocal laser scanning microscopy has become a standard technique for the investigation of hydrated interfacial microbial communities at the microscale. Multiphoton and spinning-disk microscopes provide new options for in situ imaging. Progress has been made in imaging structural aspects as well as interactions and processes. Advanced fluorescence techniques such as lifetime imaging and correlation spectroscopy are also available. Newly developed target-specific probes allow investigation of new aspects of microbial communities. Several new laser-based techniques are available including nanoscopy and mesoscale techniques. Nanoscopy techniques offer access to unprecedented resolution of hydrated microbiological samples at the scale of fluorescent gene products and macromolecules. Mesoscale approaches are important to address larger features and statistical issues of microbiological samples. This review presents the state of the art in situ biofilm imaging and assesses the pros and cons of laser-based imaging techniques in combination with a variety of sensor types at different scales. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Generalized frequency-domain synthetic aperture focusing technique for ultrasonic imaging of irregularly layered objects.

    Science.gov (United States)

    Qin, Kaihuai; Yang, Chun; Sun, Feng

    2014-01-01

    In ultrasonic nondestructive testing (NDT), the phase shift migration (PSM) technique, as a frequency-domain implementation of the synthetic aperture focusing technique (SAFT), can be adopted for imaging of regularly layered objects that are inhomogeneous only in depth but isotropic and homogeneous in the lateral direction. To deal with irregularly layered objects that are anisotropic and inhomogeneous in both the depth and lateral directions, a generalized frequency- domain SAFT, called generalized phase shift migration (GPSM), is proposed in this paper. Compared with PSM, the most significant innovation of GPSM is that the phase shift factor is generalized to handle anisotropic media with lateral velocity variations. The generalization is accomplished by computer programming techniques without modifying the PSM model. In addition, SRFFT (split-radix fast Fourier transform) input/output pruning algorithms are developed and employed in the GPSM algorithm to speed up the image reconstructions. The experiments show that the proposed imaging techniques are capable of reconstructing accurate shapes and interfaces of irregularly layered objects. The computing time of the GPSM algorithm is much less than the time-domain SAFT combined with the ray-tracing technique, which is, at present, the common method used in ultrasonic NDT industry for imaging layered objects. Furthermore, imaging regularly layered objects can be regarded as a special case of the presented technique.

  5. Micro-scanning error correction technique for an optical micro-scanning thermal microscope imaging system

    Science.gov (United States)

    Gao, Mei-Jing; Tan, Ai-Ling; Yang, Ming; Xu, Jie; Zu, Zhen-Long; Wang, Jing-Yuan

    2018-01-01

    With optical micro-scanning technology, the spatial resolution of the thermal microscope imaging system can be increased without reducing the size of the detector unit or increasing the detector dimensions. Due to optical micro-scanning error, the four low-resolution images collected by micro-scanning thermal micro- scope imaging system are not standard down-sampled images. The reconstructed image quality is degraded by the direct image interpolation with error, which influences the performance of the system. Therefore, the technique to reduce the system micro-scanning error need to be studied. Based on micro-scanning technology and combined with new edge directed interpolation(NEDI) algorithm, an error correction technique for the micro-scanning instrument is proposed. Simulations and experiments show that the proposed technique can reduce the optical micro-scanning error, improve the imaging effect of the system and improve the systems spatial resolution. It can be applied to other electro-optical imaging systems to improve their resolution.

  6. Parameters and definitions in applied technique quality test for nuclear magnetic resonance imaging system (NMRI)

    International Nuclear Information System (INIS)

    Lin Zhikai; Zhao Lancai

    1999-08-01

    During the past two decades, medical diagnostic imaging technique has achieved dramatic development such as CT, MRI, PET, DSA and so on. The most striking examples of them are the application of X ray computerized tomography (CT) and magnetic resonance imaging in the field of medical diagnosis. It can be predicted that magnetic resonance imaging (MRI) will definitely have more widespread prospects of applications and play more and more important role in clinical diagnosis looking forward to the development of image diagnostic technique for 21 st century. The authors also present the measuring methods for some parameters. The parameters described can be used for reference by clinical diagnosticians, operators on MRI and medical physicists who engages in image quality assurance (QA) and control (QC) in performing MRI acceptance test and routine test

  7. High-Performance Region-of-Interest Image Error Concealment with Hiding Technique

    Directory of Open Access Journals (Sweden)

    Shih-Chang Hsia

    2010-01-01

    Full Text Available Recently region-of-interest (ROI based image coding is a popular topic. Since ROI area contains much more important information for an image, it must be prevented from error decoding while suffering from channel lost or unexpected attack. This paper presents an efficient error concealment method to recover ROI information with a hiding technique. Based on the progressive transformation, the low-frequency components of ROI are encoded to disperse its information into the high-frequency bank of original image. The capability of protection is carried out with extracting the ROI coefficients from the damaged image without increasing extra information. Simulation results show that the proposed method can efficiently reconstruct the ROI image when ROI bit-stream occurs errors, and the measurement of PSNR result outperforms the conventional error concealment techniques by 2 to 5 dB.

  8. A Study of Advanced Image Processing Techniques on Experimental SWIFT Data

    Science.gov (United States)

    Trujillo, Christopher

    2017-06-01

    Accurately tracking the position of explosive-induced shock waves is a critical method for characterizing high explosive (HE) performance. The application of the shock wave image framing technique (SWIFT) has proven to be a successful diagnostic tool that utilizes ultra-high-speed imaging to capture time series images of explosively-driven shock waves propagating through transparent media. The use of common edge-detection algorithms, including Sobel, Canny, and Prewitt, tend to be susceptible to background noise and require noise reduction preprocessing that can alter the position of edge boundaries. In this paper, results produced by the implementation of advanced image-processing techniques on experimental SWIFT data show that shock wave position can accurately be detected and tracked, while also maintaining robustness to background image noise.

  9. Application of Genetic Algorithm and Particle Swarm Optimization techniques for improved image steganography systems

    Science.gov (United States)

    Jude Hemanth, Duraisamy; Umamaheswari, Subramaniyan; Popescu, Daniela Elena; Naaji, Antoanela

    2016-01-01

    Image steganography is one of the ever growing computational approaches which has found its application in many fields. The frequency domain techniques are highly preferred for image steganography applications. However, there are significant drawbacks associated with these techniques. In transform based approaches, the secret data is embedded in random manner in the transform coefficients of the cover image. These transform coefficients may not be optimal in terms of the stego image quality and embedding capacity. In this work, the application of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) have been explored in the context of determining the optimal coefficients in these transforms. Frequency domain transforms such as Bandelet Transform (BT) and Finite Ridgelet Transform (FRIT) are used in combination with GA and PSO to improve the efficiency of the image steganography system.

  10. [Imaging techniques for studying functional recovery following a stroke: II. Complementary techniques].

    Science.gov (United States)

    Ramos-Cabrer, Pedro; Agulla, Jesús; Rodríguez-González, Raquel; Sobrino, Tomás; Castillo, José

    2011-04-01

    Many patients that survive stroke have to face serious functional disabilities for the rest of their lives, which is a personal drama for themselves and their relatives, and an elevated charge for society. Thus, functional recovery after stroke must be a key aspect of the development of new therapeutic approaches. This is the second of a series of two works on which we review the strategies and tools available nowadays for the assessment of multiple aspects related to brain function (both in humans and research animals) and that are helping neuroscientist to better understand the processes of functional restoration and reorganization of the brain, that are triggered following stroke. We have assumed that a multidisciplinary approach is able to provide us with a wider perspective of the underlying mechanisms behind tissue repair, plastic reorganization of the brain and compensatory mechanisms, that can be triggered after stroke. In the second of the works of this series we are focusing in a series of techniques, complementary to the already discussed in the first work, and that are based on MR. These techniques are discussed separately from those ones, because they tackle with aspects not directly related to brain function, although they somehow do in indirect ways, or because they are based on physicochemical or physiological principles different from those discussed on the first work of this series.

  11. AN EFFICIENT ROBUST IMAGE WATERMARKING BASED ON AC PREDICTION TECHNIQUE USING DCT TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Gaurav Gupta

    2015-08-01

    Full Text Available The expansion of technology has made several simple ways to manipulate the original content. This has brought the concern for security of the content which is easily available in open network. Digital watermarking is the most suitable solution for the defined issue. Digital watermarking is the art of inserting the logo into multimedia object to have proof of ownership whenever it is required. The proposed algorithm is useful in authorized distribution and ownership verification. The algorithm uses the concept of AC prediction using DCT to embed the watermark in the image. The algorithm has excellent robustness against all the attacks and outperforms the similar work with admirable performance in terms of Normalized Correlation (NC, Peak Signal to Noise Ratio (PSNR and Tamper Assessment Function (TAF.

  12. Applications of digital image processing techniques to problems of data registration and correlation

    Science.gov (United States)

    Green, W. B.

    1978-01-01

    An overview is presented of the evolution of the computer configuration at JPL's Image Processing Laboratory (IPL). The development of techniques for the geometric transformation of digital imagery is discussed and consideration is given to automated and semiautomated image registration, and the registration of imaging and nonimaging data. The increasing complexity of image processing tasks at IPL is illustrated with examples of various applications from the planetary program and earth resources activities. It is noted that the registration of existing geocoded data bases with Landsat imagery will continue to be important if the Landsat data is to be of genuine use to the user community.

  13. Design and development of the associated-particle three-dimensional imaging technique

    International Nuclear Information System (INIS)

    Ussery, L.E.; Hollas, C.L.

    1994-10-01

    The authors describe the development of the ''associated-particle'' imaging technique for producing low-resolution three-dimensional images of objects. Based on the t(d,n) 4 He reaction, the method requires access to only one side of the object being imaged and allows for the imaging of individual chemical elements in the material under observation. Studies were performed to (1) select the appropriate components of the system, including detectors, data-acquisition electronics, and neutron source, and (2) optimize experimental methods for collection and presentation of data. This report describes some of the development steps involved and provides a description of the complete final system that was developed

  14. Comparative study of image registration techniques for bladder video-endoscopy

    Science.gov (United States)

    Ben Hamadou, Achraf; Soussen, Charles; Blondel, Walter; Daul, Christian; Wolf, Didier

    2009-07-01

    Bladder cancer is widely spread in the world. Many adequate diagnosis techniques exist. Video-endoscopy remains the standard clinical procedure for visual exploration of the bladder internal surface. However, video-endoscopy presents the limit that the imaged area for each image is about nearly 1 cm2. And, lesions are, typically, spread over several images. The aim of this contribution is to assess the performance of two mosaicing algorithms leading to the construction of panoramic maps (one unique image) of bladder walls. The quantitative comparison study is performed on a set of real endoscopic exam data and on simulated data relative to bladder phantom.

  15. Imaging techniques in clay sciences: a key tool to go a step further

    International Nuclear Information System (INIS)

    Robinet, J.C.; Michau, N.; Schaefer, T.

    2012-01-01

    Document available in extended abstract form only. Clay-rocks and clay based materials are greatly considered in nuclear waste geological repository due to their multiple favourable properties (low permeability, low diffusion coefficients, high retention capacity for radionuclides, swelling...). In this context, the study of clays and clay rocks covers a large variety of scientific disciplines such as geology, mineralogy, geomechanics, geochemistry or hydrodynamics. These disciplines are linked together by a common issue which is the understanding and the predicting of clay and clay-rock behaviors and properties under various thermal-hydrological-mechanical- chemical (THMC) conditions. Linking the fundamental forces to macroscopic (from millimeter to several meters) behaviors and properties is nevertheless not straightforward for porous media such as clay-rocks and clay based materials. Currently, it remains a key challenge for the scientific community. Imaging techniques offer solutions to face up this challenge by characterizing the internal microstructure of material and rocks at different levels of resolution. Due to the reactivity of clay minerals with water (swelling, mechanical deformation) or with repository components (mineral transformations at iron, copper or concrete interfaces) and the multi-scale distribution of pore and mineral sizes, classically ranged from nano-meter to millimeter, imaging clay based materials and clay-rocks itself is unanimously recognized as a challenging task. In the 80's, despite several constraints and limits, the microstructure of clays had been intensively imaged using conventional 2D imaging techniques such as optical microscopy, X-ray radiography, scanning electron microscopy or transmission electron microscopy [1]. The images acquired using these techniques have given us a pictorial frame of reference of the internal structures of clay rocks and clay based materials at various resolution levels. They have also highlighted

  16. Renal Graft Fibrosis and Inflammation Quantification by an Automated Fourier-Transform Infrared Imaging Technique.

    Science.gov (United States)

    Vuiblet, Vincent; Fere, Michael; Gobinet, Cyril; Birembaut, Philippe; Piot, Olivier; Rieu, Philippe

    2016-08-01

    Renal interstitial fibrosis and interstitial active inflammation are the main histologic features of renal allograft biopsy specimens. Fibrosis is currently assessed by semiquantitative subjective analysis, and color image analysis has been developed to improve the reliability and repeatability of this evaluation. However, these techniques fail to distinguish fibrosis from constitutive collagen or active inflammation. We developed an automatic, reproducible Fourier-transform infrared (FTIR) imaging-based technique for simultaneous quantification of fibrosis and inflammation in renal allograft biopsy specimens. We generated and validated a classification model using 49 renal biopsy specimens and subsequently tested the robustness of this classification algorithm on 166 renal grafts. Finally, we explored the clinical relevance of fibrosis quantification using FTIR imaging by comparing results with renal function at 3 months after transplantation (M3) and the variation of renal function between M3 and M12. We showed excellent robustness for fibrosis and inflammation classification, with >90% of renal biopsy specimens adequately classified by FTIR imaging. Finally, fibrosis quantification by FTIR imaging correlated with renal function at M3, and the variation in fibrosis between M3 and M12 correlated well with the variation in renal function over the same period. This study shows that FTIR-based analysis of renal graft biopsy specimens is a reproducible and reliable label-free technique for quantifying fibrosis and active inflammation. This technique seems to be more relevant than digital image analysis and promising for both research studies and routine clinical practice. Copyright © 2016 by the American Society of Nephrology.

  17. Fast in vivo bioluminescence tomography using a novel pure optical imaging technique

    Directory of Open Access Journals (Sweden)

    Shuang Zhang

    2017-05-01

    Full Text Available Bioluminescence tomography (BLT is a novel optical molecular imaging technique that advanced the conventional planar bioluminescence imaging (BLI into a quantifiable three-dimensional (3D approach in preclinical living animal studies in oncology. In order to solve the inverse problem and reconstruct tumor lesions inside animal body accurately, the prior structural information is commonly obtained from X-ray computed tomography (CT. This strategy requires a complicated hybrid imaging system, extensive post imaging analysis and involvement of ionizing radiation. Moreover, the overall robustness highly depends on the fusion accuracy between the optical and structural information. Here, we present a pure optical bioluminescence tomographic (POBT system and a novel BLT workflow based on multi-view projection acquisition and 3D surface reconstruction. This method can reconstruct the 3D surface of an imaging subject based on a sparse set of planar white-light and bioluminescent images, so that the prior structural information can be offered for 3D tumor lesion reconstruction without the involvement of CT. The performance of this novel technique was evaluated through the comparison with a conventional dual-modality tomographic (DMT system and a commercialized optical imaging system (IVIS Spectrum using three breast cancer xenografts. The results revealed that the new technique offered comparable in vivo tomographic accuracy with the DMT system (P>0.05 in much shorter data analysis time. It also offered significantly better accuracy comparing with the IVIS system (P<0.04 without sacrificing too much time.

  18. Recent developments in spectroscopic imaging techniques for historical paintings - A review

    Science.gov (United States)

    Alfeld, M.; de Viguerie, L.

    2017-10-01

    This paper provides an overview over the application of scanning macro-XRF with mobile instruments for the investigation of historical paintings. The method is compared to synchrotron based macro-XRF imaging and Neutron Activation Auto-Radiography. Full-Field XRF imaging instruments, a potential future alternative to scanning macro-XRF, and confocal XRF, providing complementary depth profiles and developing into a 3D imaging technique itself, are described with the focus on investigations of historical paintings. Recent developments of X-ray radiography are presented and the investigation of cultural heritage objects other than paintings by MA-XRF is summarized. In parallel to XRF, hyperspectral imaging in the visible and range has developed into a technique with comparable capabilities, providing insight in chemical compounds, where XRF imaging identifies the distribution of elements. Due to the complementary nature of these techniques the latter is summarized. Further, progress and state of the art in data evaluation for spectroscopic imaging is discussed. In general it could be observed that technical capabilities in MA-XRF and hyperspectral imaging have reached a plateau and that with the availability of commercial instruments the focus of recent studies has shifted from the development of methods to applications of the instruments. Further, that while simple instruments are easily available with medium budgets only few groups have high-end instrumentation available, bought or in-house built.

  19. A Block-matching based technique for the analysis of 2D gel images.

    Science.gov (United States)

    Freire, Ana; Seoane, José A; Rodríguez, Alvaro; Ruiz-Romero, Cristina; López-Campos, Guillermo; Dorado, Julián

    2010-01-01

    Research at protein level is a useful practice in personalized medicine. More specifically, 2D gel images obtained after electrophoresis process can lead to an accurate diagnosis. Several computational approaches try to help the clinicians to establish the correspondence between pairs of proteins of multiple 2D gel images. Most of them perform the alignment of a patient image referred to a reference image. In this work, an approach based on block-matching techniques is developed. Its main characteristic is that it does not need to perform the whole alignment between two images considering each protein separately. A comparison with other published methods is presented. It can be concluded that this method works over broad range of proteomic images, although they have a high level of difficulty.

  20. Data Reduction and Image Reconstruction Techniques for Non-redundant Masking

    Science.gov (United States)

    Sallum, S.; Eisner, J.

    2017-11-01

    The technique of non-redundant masking (NRM) transforms a conventional telescope into an interferometric array. In practice, this provides a much better constrained point-spread function than a filled aperture and thus higher resolution than traditional imaging methods. Here, we describe an NRM data reduction pipeline. We discuss strategies for NRM observations regarding dithering patterns and calibrator selection. We describe relevant image calibrations and use example Large Binocular Telescope data sets to show their effects on the scatter in the Fourier measurements. We also describe the various ways to calculate Fourier quantities, and discuss different calibration strategies. We present the results of image reconstructions from simulated observations where we adjust prior images, weighting schemes, and error bar estimation. We compare two imaging algorithms and discuss implications for reconstructing images from real observations. Finally, we explore how the current state of the art compares to next-generation Extremely Large Telescopes.

  1. Algebraic Reconstruction Technique (ART) for parallel imaging reconstruction of undersampled radial data: Application to cardiac cine

    Science.gov (United States)

    Li, Shu; Chan, Cheong; Stockmann, Jason P.; Tagare, Hemant; Adluru, Ganesh; Tam, Leo K.; Galiana, Gigi; Constable, R. Todd; Kozerke, Sebastian; Peters, Dana C.

    2014-01-01

    Purpose To investigate algebraic reconstruction technique (ART) for parallel imaging reconstruction of radial data, applied to accelerated cardiac cine. Methods A GPU-accelerated ART reconstruction was implemented and applied to simulations, point spread functions (PSF) and in twelve subjects imaged with radial cardiac cine acquisitions. Cine images were reconstructed with radial ART at multiple undersampling levels (192 Nr x Np = 96 to 16). Images were qualitatively and quantitatively analyzed for sharpness and artifacts, and compared to filtered back-projection (FBP), and conjugate gradient SENSE (CG SENSE). Results Radial ART provided reduced artifacts and mainly preserved spatial resolution, for both simulations and in vivo data. Artifacts were qualitatively and quantitatively less with ART than FBP using 48, 32, and 24 Np, although FBP provided quantitatively sharper images at undersampling levels of 48-24 Np (all pparallel radial MR imaging, providing reduced artifacts while mainly maintaining sharpness compared to FBP, as shown by its first application in cardiac studies. PMID:24753213

  2. Image restoration techniques using Compton backscatter imaging for the detection of buried land mines

    Science.gov (United States)

    Wehlburg, Joseph C.; Keshavmurthy, Shyam P.; Watanabe, Yoichi; Dugan, Edward T.; Jacobs, Alan M.

    1995-06-01

    Earlier landmine imaging systems used two collimated detectors to image objects. These systems had difficulty in distinguishing between surface features and buried features. Using a combination of collimated and uncollimated detectors in a Compton backscatter imaging (CBI) system, allows the identification of surface and buried features. Images created from the collimated detectors contain information about the surface and the buried features, while the uncollimated detectors respond (approximately 80%) to features on the surface. The analysis of surface features are performed first, then these features can be removed and the buried features can be identified. Separation of the surface and buried features permits the use of a globbing algorithm to define regions of interest that can then be quantified [area, Y dimension, X dimension, and center location (xo, yo)]. Mine composition analysis is also possible because of the properties of the four detector system. Distinguishing between a pothole and a mine, that was previously very difficult, can now be easily accomplished.

  3. Elastography as a hybrid imaging technique : coupling with photoacoustics and quantitative imaging

    International Nuclear Information System (INIS)

    Widlak, T.G.

    2015-01-01

    While classical imaging methods, such as ultrasound, computed tomography or magnetic resonance imaging, are well-known and mathematically understood, a host of physiological parameters relevant for diagnostic purposes cannot be obtained by them. This gap is recently being closed by the introduction of hybrid, or coupled-physics imaging methods. They connect more then one physical modality, and aim to provide quantitative information on optical, electrical or mechanical parameters with high resolution. Central to this thesis is the mechanical contrast of elastic tissue, especially Young’s modulus or the shear modulus. Different methods of qualitative elastography provide interior information of the mechanical displacement field. From this interior data the nonlinear inverse problem of quantitative elastography aims to reconstruct the shear modulus. In this thesis, the elastography problem is seen from a hybrid imaging perspective; methods from coupled-physics inspired literature and regularization theory have been employed to recover displacement and shear modulus information. The overdetermined systems approach by G. Bal is applied to the quantitative problem, and ellipticity criteria are deduced, for one and several measurements, as well as injectivity results. Together with the geometric theory of G. Chavent, the results are used for analyzing convergence of Tikhonov regularization. Also, a convergence analysis for the Levenberg Marquardt method is provided. As a second mainstream project in this thesis, elastography imaging is developed for extracting displacements from photoacoustic images. A novel method is provided for texturizing the images, and the optical flow problem for motion estimation is shown to be regularized with this texture generation. The results are tested in cooperation with the Medical University Vienna, and the methods for quantitative determination of the shear modulus evaluated in first experiments. In summary, the overdetermined systems

  4. Methodology for attainment of density and effective atomic number through dual energy technique using microtomographic images

    International Nuclear Information System (INIS)

    Alves, H.; Lima, I.; Lopes, R.T.

    2014-01-01

    Dual energy technique for computerized microtomography shows itself as a promising method for identification of mineralogy on geological samples of heterogeneous composition. It can also assist with differentiating very similar objects regarding the attenuation coefficient, which are usually not separable during image processing and analysis of microtomographic data. Therefore, the development of a feasible and applicable methodology of dual energy in the analysis of microtomographic images was sought. - Highlights: • Dual energy technique is promising for identification of distribution of minerals. • A feasible methodology of dual energy in analysis of tomographic images was sought. • The dual energy technique is efficient for density and atomic number identification. • Simulation showed that the proposed methodology agrees with theoretical data. • Nondestructive characterization of distribution of density and chemical composition

  5. Neutron, fluorescence, and optical imaging: An in situ combination of complementary techniques

    International Nuclear Information System (INIS)

    Wagner, D.; Egelhaaf, S. U.; Hermes, H. E.; Börgardts, M.; Müller, T. J. J.; Grünzweig, C.; Lehmann, E.

    2015-01-01

    An apparatus which enables the simultaneous combination of three complementary imaging techniques, optical imaging, fluorescence imaging, and neutron radiography, is presented. While each individual technique can provide information on certain aspects of the sample and their time evolution, a combination of the three techniques in one setup provides a more complete and consistent data set. The setup can be used in transmission and reflection modes and thus with optically transparent as well as opaque samples. Its capabilities are illustrated with two examples. A polymer hydrogel represents a transparent sample and the diffusion of fluorescent particles into and through this polymer matrix is followed. In reflection mode, the absorption of solvent by a nile red-functionalized mesoporous silica powder and the corresponding change in fluorescent signal are studied

  6. A Novel Technique to Improve Photometry in Confused Images Using Graphs and Bayesian Priors

    Science.gov (United States)

    Safarzadeh, Mohammadtaher; Ferguson, Henry C.; Lu, Yu; Inami, Hanae; Somerville, Rachel S.

    2015-01-01

    We present a new technique for overcoming confusion noise in deep far-infrared Herschel space telescope images making use of prior information from shorter λ posterior probability distribution function of fluxes subject to these priors through Monte Carlo Markov Chain (MCMC) sampling by fitting the image. Assuming we can predict the FIR flux of sources based on the ultraviolet-optical part of their SEDs to within an order of magnitude, the simulations show that we can obtain reliable fluxes and uncertainties at least a factor of three fainter than the confusion noise limit of 3σ c = 2.7 mJy in our simulated PACS-160 image. This technique could in principle be used to mitigate the effects of source confusion in any situation where one has prior information of positions and plausible fluxes of blended sources. For Herschel, application of this technique will improve our ability to constrain the dust content in normal galaxies at high redshift.

  7. The Effect of Mental Imaging Technique on Idiom Comprehension in EFL Learners

    Directory of Open Access Journals (Sweden)

    Burcu AYDIN

    2017-12-01

    Full Text Available In an English Foreign Language learning context, where access to native like use of metaphorical language is limited, gaining this ability becomes challenging. For many years, foreign language educators didn’t pay much attention to idiomatic language and assumed that idioms could only be taught through rote learning. For this reason, they face with difficulties in using appropriate approaches to idiom instruction. Furthermore, learners struggle with comprehending and practicing idioms. To resolve the concern, linguists are trying to develop cognitive approaches to the teaching of idiomatic language. The purpose of this study is to provide educators with guidelines to choose the appropriate idiom teaching technique for English Foreign Language learners taking into account the learners’ metaphorical competence level and their cognitive style preferences. In evaluating the appropriate teaching technique, three different techniques (context out, context in and mental imaging technique were used. The participants were presented 50 idioms. As a first technique, context out, idioms were taught with their definitions in the dictionary without additional contextual support. As a second technique, context in, in an attempt to investigate the effect of contextual support, idioms were both presented in a sentence and with their definitions. As a third technique, mental imaging technique, in an attempt to investigate the effect of Dual Coding approach, both pictorial representations of a mapping of literal senses of each idiomatic expression and verbal support (the definition of the idiom and the sentence in which the idiom is used were used concurrently. The findings point that mental imaging technique has positive effect on learning and recalling of the idiomatic expressions as it provides simultaneous verbal information with mental image which creates a supplementary pathway for recollecting the verbal information. In contrast, the results indicate no

  8. Imaging of acute pulmonary embolism using multi-detector CT angiography: An update on imaging technique and interpretation

    International Nuclear Information System (INIS)

    Hartmann, Ieneke J.C.; Wittenberg, Rianne; Schaefer-Prokop, Cornelia

    2010-01-01

    Computed tomography angiography (CTA) of the pulmonary arteries has become the main diagnostic test for the evaluation of pulmonary embolism (PE). Not only due to the good availability, low cost and minimal invasiveness of this technique, but mainly because of the introduction of multi-detector CT techniques resulting in significant improvement in resolution, speed and image quality. This continuous gain in image acquisition speed went along with the introduction of new techniques of image acquisition, such as the dual-source CT scanning and novel concepts of image interpretation beyond morphological findings including the definition of the resulting perfusion defects and assessment of the cardiopulmonary circulation as a functional unit. This article will focus on technical and practical aspects to optimize CTPA examinations with modern multi-detector CT scanners, discusses aspects to be considered in specific patient groups (e.g., during pregnancy, young patients) and outlines new advents such as dual-source lung perfusion and automatic detection of pulmonary emboli.

  9. Imaging of acute pulmonary embolism using multi-detector CT angiography: An update on imaging technique and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Ieneke J.C. [Department of Radiology, Erasmus MC University Medical Centre, ' s-Gravendijkwal 230, NL-3015 CE Rotterdam (Netherlands)], E-mail: i.hartmann@erasmusmc.nl; Wittenberg, Rianne [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Department of Radiology, University Medical Centre, Utrecht (Netherlands); Schaefer-Prokop, Cornelia [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Department of Radiology, Meander Medical Centre, Amersfoort (Netherlands)

    2010-04-15

    Computed tomography angiography (CTA) of the pulmonary arteries has become the main diagnostic test for the evaluation of pulmonary embolism (PE). Not only due to the good availability, low cost and minimal invasiveness of this technique, but mainly because of the introduction of multi-detector CT techniques resulting in significant improvement in resolution, speed and image quality. This continuous gain in image acquisition speed went along with the introduction of new techniques of image acquisition, such as the dual-source CT scanning and novel concepts of image interpretation beyond morphological findings including the definition of the resulting perfusion defects and assessment of the cardiopulmonary circulation as a functional unit. This article will focus on technical and practical aspects to optimize CTPA examinations with modern multi-detector CT scanners, discusses aspects to be considered in specific patient groups (e.g., during pregnancy, young patients) and outlines new advents such as dual-source lung perfusion and automatic detection of pulmonary emboli.

  10. Image Processing Based Signature Verification Technique to Reduce Fraud in Financial Institutions

    Directory of Open Access Journals (Sweden)

    Hussein Walid

    2016-01-01

    Full Text Available Handwritten signature is broadly utilized as personal verification in financial institutions ensures the necessity for a robust automatic signature verification tool. This tool aims to reduce fraud in all related financial transactions’ sectors. This paper proposes an online, robust, and automatic signature verification technique using the recent advances in image processing and machine learning. Once the image of a handwritten signature for a customer is captured, several pre-processing steps are performed on it including filtration and detection of the signature edges. Afterwards, a feature extraction process is applied on the image to extract Speeded up Robust Features (SURF and Scale-Invariant Feature Transform (SIFT features. Finally, a verification process is developed and applied to compare the extracted image features with those stored in the database for the specified customer. Results indicate high accuracy, simplicity, and rapidity of the developed technique, which are the main criteria to judge a signature verification tool in banking and other financial institutions.

  11. Iterative deconvolution technique for measurements of diffraction-limited images on optical microscopes.

    Science.gov (United States)

    Lu, Wenlong; Chang, Ming; Chen, Po-Cheng; Luo, Wun-Mao

    2014-12-12

    Diffraction limit is usually a thorny problem in an optical inspection system. In this investigation, a model-based deconvolution technique was developed to recover diffraction-limited images, where images with sizes smaller than the diffraction limit could be recognized. Experiments were carried out with a traditional microscope at 200× magnification coupled with a halogen light source for a series of line width samples. The point spread function of the imaging optics was first obtained from an estimated model and then combined with a nonlinear deconvolution algorithm to calculate the full width at half maximum and reconstruct the line widths. Experimental results indicate that a measurement error below one pixel size of the measurement system is achievable. Accordingly, the target of nanoscale line width inspection based on a low cost and real-time image processing technique can be fulfilled, which greatly increases the ability of nanoscaling on optical microscopes.

  12. Dental CT: imaging technique, anatomy, and pathologic conditions of the jaws

    International Nuclear Information System (INIS)

    Gahleitner, Andre; Watzek, G.; Imhof, H.

    2003-01-01

    In addition to conventional imaging methods, dental CT has become an established method for anatomic imaging of the jaws prior to dental implant placement. More recently, this high-resolution imaging technique has gained importance in diagnosing dental-associated diseases of the mandible and maxilla. Since most radiologists have had little experience in these areas, many of the CT findings remain undescribed. The objective of this review article is to present the technique of dental CT, to illustrate the typical appearance of jaw anatomy and dental-related diseases of the jaws with dental CT, and to show where it can serve as an addition to conventional imaging methods in dental radiology. (orig.)

  13. Advanced techniques in magnetic resonance imaging of the brain in children with ADHD

    Energy Technology Data Exchange (ETDEWEB)

    Pastura, Giuseppe, E-mail: giuseppe.pastura@terra.com.b [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Puericultura e Pediatria Martagao Gesteira. Dept. de Pediatria; Mattos, Paulo [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Puericultura e Pediatria Martagao Gesteira. Dept. de Psiquiatria; Gasparetto, Emerson Leandro [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Puericultura e Pediatria Martagao Gesteira. Dept. de Radiologia; Araujo, Alexandra Prufer de Queiroz Campos [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Puericultura e Pediatria Martagao Gesteira. Dept. de Neuropediatria

    2011-04-15

    Attention deficit hyperactivity disorder (ADHD) affects about 5% of school-aged child. Previous published works using different techniques of magnetic resonance imaging (MRI) have demonstrated that there may be some differences between the brain of people with and without this condition. This review aims at providing neurologists, pediatricians and psychiatrists an update on the differences between the brain of children with and without ADHD using advanced techniques of magnetic resonance imaging such as diffusion tensor imaging, brain volumetry and cortical thickness, spectroscopy and functional MRI. Data was obtained by a comprehensive, non-systematic review of medical literature. The regions with a greater number of abnormalities are splenium of the corpus callosum, cingulated gyrus, caudate nucleus, cerebellum, striatum, frontal and temporal cortices. The brain regions where abnormalities are observed in studies of diffusion tensor, volumetry, spectroscopy and cortical thickness are the same involved in neurobiological theories of ADHD coming from studies with functional magnetic resonance imaging. (author)

  14. Dental CT: imaging technique, anatomy, and pathologic conditions of the jaws

    Energy Technology Data Exchange (ETDEWEB)

    Gahleitner, Andre [Department of Radiology/Osteology, Medical School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria); Department of Oral Surgery, Dental School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria); Watzek, G. [Department of Oral Surgery, Dental School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria); Imhof, H. [Department of Radiology/Osteology, Medical School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria)

    2003-02-01

    In addition to conventional imaging methods, dental CT has become an established method for anatomic imaging of the jaws prior to dental implant placement. More recently, this high-resolution imaging technique has gained importance in diagnosing dental-associated diseases of the mandible and maxilla. Since most radiologists have had little experience in these areas, many of the CT findings remain undescribed. The objective of this review article is to present the technique of dental CT, to illustrate the typical appearance of jaw anatomy and dental-related diseases of the jaws with dental CT, and to show where it can serve as an addition to conventional imaging methods in dental radiology. (orig.)

  15. Advanced techniques in magnetic resonance imaging of the brain in children with ADHD

    International Nuclear Information System (INIS)

    Pastura, Giuseppe; Mattos, Paulo; Gasparetto, Emerson Leandro; Araujo, Alexandra Prufer de Queiroz Campos

    2011-01-01

    Attention deficit hyperactivity disorder (ADHD) affects about 5% of school-aged child. Previous published works using different techniques of magnetic resonance imaging (MRI) have demonstrated that there may be some differences between the brain of people with and without this condition. This review aims at providing neurologists, pediatricians and psychiatrists an update on the differences between the brain of children with and without ADHD using advanced techniques of magnetic resonance imaging such as diffusion tensor imaging, brain volumetry and cortical thickness, spectroscopy and functional MRI. Data was obtained by a comprehensive, non-systematic review of medical literature. The regions with a greater number of abnormalities are splenium of the corpus callosum, cingulated gyrus, caudate nucleus, cerebellum, striatum, frontal and temporal cortices. The brain regions where abnormalities are observed in studies of diffusion tensor, volumetry, spectroscopy and cortical thickness are the same involved in neurobiological theories of ADHD coming from studies with functional magnetic resonance imaging. (author)

  16. An image enhancement technique using nonlinear transfer function and unsharp masking in multispectral endoscope

    Science.gov (United States)

    Zhang, Kejian; Wang, Huan; Yuan, Bo; Wang, Liqiang

    2017-01-01

    This paper studies the realization of image processing algorithm of multispectral endoscope. The research contents include: local brightness enhancement and adaptive contrast enhancement. Firstly, this paper transforms the image from the RGB space to the HSV space, and then carries on the image enhancement processing to the V space, finally transforms to the RGB space. Local brightness enhancement algorithm divides V space image into smaller windows, and then calculates the nonlinear transfer function of each window, which enhances the pixels in the window, and finally the contrast of brightness enhanced image is restored. The adaptive contrast enhancement adopts the unsharp mask technique based on the guided filter. First of all, this paper uses guided filter to the RGB channel of the original image and gets the unsharp mask of each channel, then plus a scaled image which is the result of the original image subtracts the unsharp mask. So the enhancement of the image is achieved. This paper uses subjective evaluation criteria and enhance factor α to evaluate the effect of enhancement. And this paper compares the enhancement effect of the proposed image enhancement algorithm and the traditional algorithm. The results show that the α of histogram equalization is smallest and AINDANE method is better than histogram equalization. The proposed method has the best α. The subjective evaluation also shows that the effect of HE is not satisfactory and the proposed method enhances the detail information tremendously. The subjective and objective criteria shows that the proposed method produces better enhancement effect.

  17. Performance Evaluation of Frequency Transform Based Block Classification of Compound Image Segmentation Techniques

    Science.gov (United States)

    Selwyn, Ebenezer Juliet; Florinabel, D. Jemi

    2018-04-01

    Compound image segmentation plays a vital role in the compression of computer screen images. Computer screen images are images which are mixed with textual, graphical, or pictorial contents. In this paper, we present a comparison of two transform based block classification of compound images based on metrics like speed of classification, precision and recall rate. Block based classification approaches normally divide the compound images into fixed size blocks of non-overlapping in nature. Then frequency transform like Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are applied over each block. Mean and standard deviation are computed for each 8 × 8 block and are used as features set to classify the compound images into text/graphics and picture/background block. The classification accuracy of block classification based segmentation techniques are measured by evaluation metrics like precision and recall rate. Compound images of smooth background and complex background images containing text of varying size, colour and orientation are considered for testing. Experimental evidence shows that the DWT based segmentation provides significant improvement in recall rate and precision rate approximately 2.3% than DCT based segmentation with an increase in block classification time for both smooth and complex background images.

  18. A Partnership Training Program in Breast Cancer Research Using Molecular Imaging Techniques

    Science.gov (United States)

    2008-07-01

    behavior of calcium, stimulates bone formation and has been used in the treatment of post menopausal osteoporosis . There have been several reports on anti...using molecular imaging techniques. 2. Offer molecular imaging and breast cancer- related lectures, seminars, workshops, and laboratory internships. 3...bioluminescence assay system was related to the number of viable cells over a wide range (102 to 105 cells per well). The decrease in luminescence was

  19. A Partnership Training Program in Breast Cancer Research Using Molecular Imaging Techniques

    Science.gov (United States)

    2007-07-01

    tiny calcium deposits that 82 indicate changes within the breast possibly point- 83 ing to cancer . Microcalcifications especially are 84 usually...NUMBER A Partnership Training Program in Breast Cancer Research Using Molecular Imaging Techniques 5b. GRANT NUMBER W81XWH-05-1-0291 5c. PROGRAM...assistant were further trained in molecular imaging of breast cancer through seminars and workshops, and are currently conducting two research projects

  20. A 3-D definition of a pipe wall location using image processing techniques

    Science.gov (United States)

    Zeltser, Refael

    1988-06-01

    Measurements of fluid flow through a flexible tube are important in defining blood flow through an artery. One method is an image processing technique called rasterography, which uses a grid, optically projected on the tube from a given angle, and photographed from a different angle. The image is digitized into a computer and processed. The output consists of a 3-D description of a tube wall location after assigning height coordinates to defined x,y coordinates in the photograph.

  1. Determination of toxigenic fungi and aflatoxins in nuts and dried fruits using imaging and spectroscopic techniques.

    Science.gov (United States)

    Wu, Qifang; Xie, Lijuan; Xu, Huirong

    2018-06-30

    Nuts and dried fruits contain rich nutrients and are thus highly vulnerable to contamination with toxigenic fungi and aflatoxins because of poor weather, processing and storage conditions. Imaging and spectroscopic techniques have proven to be potential alternative tools to wet chemistry methods for efficient and non-destructive determination of contamination with fungi and toxins. Thus, this review provides an overview of the current developments and applications in frequently used food safety testing techniques, including near infrared spectroscopy (NIRS), mid-infrared spectroscopy (MIRS), conventional imaging techniques (colour imaging (CI) and hyperspectral imaging (HSI)), and fluorescence spectroscopy and imaging (FS/FI). Interesting classification and determination results can be found in both static and on/in-line real-time detection for contaminated nuts and dried fruits. Although these techniques offer many benefits over conventional methods, challenges remain in terms of heterogeneous distribution of toxins, background constituent interference, model robustness, detection limits, sorting efficiency, as well as instrument development. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. New techniques for resolution enhancement of 3D x-ray tomographic imaging from incomplete data

    International Nuclear Information System (INIS)

    Vengrinovich, V.; Zolotarev, S.; Denkevich, Y.; Tillack, G.-R.

    2004-01-01

    Accurate evaluation of dimensions directly from tomographic images, restored from only few x-ray projections, made in a limited observation sector, is considered exploiting pipes wall thickness assessment like a typical example. Both experiments and simulations are used to extract main errors sources. It is taken from as known, that neglecting of the scattered radiation and beam hardening effects results in image blurring, strong artifacts and finally inaccurate sizing. The computerized technique is developed to simulate the contribution of scattered radiation and beam hardening for the purpose of their further extraction from projected data. After those accompanying effects extraction the iterative Bayesian techniques are applied to reconstruct images from the projections, using volumetric and/or shell representation of the objects like pipes. The achieved error of virtual pipe wall thickness assessment from 3D images can be as small as 300μk comparing to 1mm provided by modern techniques. Finally the conclusion was drawn that standard projection techniques using X- or Gamma rays in combination with X-ray film or imaging plates can be applied for the data acquisition to reconstruct finally wall thickness profiles in an in-field environment. (author)

  3. Ultrasound Imaging Techniques for Spatiotemporal Characterization of Composition, Microstructure, and Mechanical Properties in Tissue Engineering.

    Science.gov (United States)

    Deng, Cheri X; Hong, Xiaowei; Stegemann, Jan P

    2016-08-01

    Ultrasound techniques are increasingly being used to quantitatively characterize both native and engineered tissues. This review provides an overview and selected examples of the main techniques used in these applications. Grayscale imaging has been used to characterize extracellular matrix deposition, and quantitative ultrasound imaging based on the integrated backscatter coefficient has been applied to estimating cell concentrations and matrix morphology in tissue engineering. Spectral analysis has been employed to characterize the concentration and spatial distribution of mineral particles in a construct, as well as to monitor mineral deposition by cells over time. Ultrasound techniques have also been used to measure the mechanical properties of native and engineered tissues. Conventional ultrasound elasticity imaging and acoustic radiation force imaging have been applied to detect regions of altered stiffness within tissues. Sonorheometry and monitoring of steady-state excitation and recovery have been used to characterize viscoelastic properties of tissue using a single transducer to both deform and image the sample. Dual-mode ultrasound elastography uses separate ultrasound transducers to produce a more potent deformation force to microscale characterization of viscoelasticity of hydrogel constructs. These ultrasound-based techniques have high potential to impact the field of tissue engineering as they are further developed and their range of applications expands.

  4. Imaging of the central nervous system with combined half-Fourier and rectangular pixel technique

    International Nuclear Information System (INIS)

    Runge, V.M.; Wood, M.L.; Wolf, C.R.; Carollo, B.R.

    1988-01-01

    The diagnostic value of a combined half-Fourier and rectangular pixel technique for T2-weighted imaging of the central nervous system (CNS) was assessed with results obtained in 45 patients. This technique presents a new approach to T2 screening of the CNS. Imaging time is cut by a factor of approximately four, with no compromise in signal-to-noise ratio and spatial resolution equivalent to a 256X128 matrix. Gradient moment nulling is essential in order to minimize flow artifacts. Lesion detection is equivalent to a 256X256 matrix in the worst case, that is, for detection of small punctate abnormalities (multiple sclerosis plaques)

  5. High-resolution texture imaging with hard synchrotron radiation in the moving area detector technique

    CERN Document Server

    Wcislak, L; Klein, H; Garbe, U; Schneider, J R

    2003-01-01

    The orientation distribution of crystallites in polycrystalline materials (called texture) is usually measured by polycrystal X-ray diffraction by 'step-scanning' the sample in angular intervals in the order of 1 deg. This technique is not suited to fully exploit the low angular divergence of hard synchrotron radiation in the order of 'milliradian'. Hence, step-scanning was replaced by a continuous 'sweeping' technique using a continuously shifted area detector. In order to avoid overlapping from different reflections (hkl) a Bragg-angle slit was introduced. The 'moving-detector' technique can be applied to obtain images of orientation as well as of location distributions of crystallites in polycrystalline samples. It is suitable for imaging continuous 'orientation density' distribution functions as well as of 'grain-resolved' textures. The excellent features of high-energy synchrotron radiation combined with the moving area detector technique will be illustrated with several examples including very sharp def...

  6. What imaging techniques should be used in primary versus secondary prevention for further risk stratification?

    Science.gov (United States)

    Schiele, François; Navarese, Eliano Pio; Visoná, Adriana; Ray, Kausik

    2017-04-01

    An accurate assessment of the cardiovascular (CV) risk of an individual is key for guiding the appropriate treatment strategy for cardiovascular disease (CVD). Although conventional risk factors for CVD are well established, there can be substantial variation in the extent of atherosclerosis between patients. The use of a variety of imaging modalities can be beneficial in the primary prevention stage and in the classification of an individual's CV risk. Therefore, appropriate implementation of these imaging techniques for risk assessment purposes, in line with clinical guidelines, can influence the outcomes of CVD prevention. The expert working group collaborated to review current invasive and non-invasive imaging techniques available to healthcare practitioners and how they can be used in the measurement of preclinical vascular damage and CV risk assessment. After evaluation of the current guideline recommendations and clinical data available, the expert working group collaborated to produce recommendations regarding the use of imaging in the risk stratification in primary prevention, CV risk in peri-acute coronary syndrome and CV risk assessment in secondary prevention. Overall, a variety of both invasive and non-invasive imaging modalities were highlighted by the expert working group as having the potential to assist in the risk assessments of patients at risk of CVD. These imaging techniques can be utilised in both primary and secondary prevention strategies and have the potential to be important risk modifiers, improving the outcome of CV risk assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Histological validation of near-infrared reflectance multispectral imaging technique for caries detection and quantification.

    Science.gov (United States)

    Salsone, Silvia; Taylor, Andrew; Gomez, Juliana; Pretty, Iain; Ellwood, Roger; Dickinson, Mark; Lombardo, Giuseppe; Zakian, Christian

    2012-07-01

    Near infrared (NIR) multispectral imaging is a novel noninvasive technique that maps and quantifies dental caries. The technique has the ability to reduce the confounding effect of stain present on teeth. The aim of this study was to develop and validate a quantitative NIR multispectral imaging system for caries detection and assessment against a histological reference standard. The proposed technique is based on spectral imaging at specific wavelengths in the range from 1000 to 1700 nm. A total of 112 extracted teeth (molars and premolars) were used and images of occlusal surfaces at different wavelengths were acquired. Three spectral reflectance images were combined to generate a quantitative lesion map of the tooth. The maximum value of the map at the corresponding histological section was used as the NIR caries score. The NIR caries score significantly correlated with the histological reference standard (Spearman's Coefficient=0.774, p<0.01). Caries detection sensitivities and specificities of 72% and 91% for sound areas, 36% and 79% for lesions on the enamel, and 82% and 69% for lesions in dentin were found. These results suggest that NIR spectral imaging is a novel and promising method for the detection, quantification, and mapping of dental caries.

  8. Novel region of interest interrogation technique for diffusion tensor imaging analysis in the canine brain.

    Science.gov (United States)

    Li, Jonathan Y; Middleton, Dana M; Chen, Steven; White, Leonard; Ellinwood, N Matthew; Dickson, Patricia; Vite, Charles; Bradbury, Allison; Provenzale, James M

    2017-08-01

    Purpose We describe a novel technique for measuring diffusion tensor imaging metrics in the canine brain. We hypothesized that a standard method for region of interest placement could be developed that is highly reproducible, with less than 10% difference in measurements between raters. Methods Two sets of canine brains (three seven-week-old full-brains and two 17-week-old single hemispheres) were scanned ex-vivo on a 7T small-animal magnetic resonance imaging system. Strict region of interest placement criteria were developed and then used by two raters to independently measure diffusion tensor imaging metrics within four different white-matter regions within each specimen. Average values of fractional anisotropy, radial diffusivity, and the three eigenvalues (λ1, λ2, and λ3) within each region in each specimen overall and within each individual image slice were compared between raters by calculating the percentage difference between raters for each metric. Results The mean percentage difference between raters for all diffusion tensor imaging metrics when pooled by each region and specimen was 1.44% (range: 0.01-5.17%). The mean percentage difference between raters for all diffusion tensor imaging metrics when compared by individual image slice was 2.23% (range: 0.75-4.58%) per hemisphere. Conclusion Our results indicate that the technique described is highly reproducible, even when applied to canine specimens of differing age, morphology, and image resolution. We propose this technique for future studies of diffusion tensor imaging analysis in canine brains and for cross-sectional and longitudinal studies of canine brain models of human central nervous system disease.

  9. Mathematical Foundation Based Inter-Connectivity modelling of Thermal Image processing technique for Fire Protection

    Directory of Open Access Journals (Sweden)

    Sayantan Nath

    2015-09-01

    Full Text Available In this paper, integration between multiple functions of image processing and its statistical parameters for intelligent alarming series based fire detection system is presented. The proper inter-connectivity mapping between processing elements of imagery based on classification factor for temperature monitoring and multilevel intelligent alarm sequence is introduced by abstractive canonical approach. The flow of image processing components between core implementation of intelligent alarming system with temperature wise area segmentation as well as boundary detection technique is not yet fully explored in the present era of thermal imaging. In the light of analytical perspective of convolutive functionalism in thermal imaging, the abstract algebra based inter-mapping model between event-calculus supported DAGSVM classification for step-by-step generation of alarm series with gradual monitoring technique and segmentation of regions with its affected boundaries in thermographic image of coal with respect to temperature distinctions is discussed. The connectedness of the multifunctional operations of image processing based compatible fire protection system with proper monitoring sequence is presently investigated here. The mathematical models representing the relation between the temperature affected areas and its boundary in the obtained thermal image defined in partial derivative fashion is the core contribution of this study. The thermal image of coal sample is obtained in real-life scenario by self-assembled thermographic camera in this study. The amalgamation between area segmentation, boundary detection and alarm series are described in abstract algebra. The principal objective of this paper is to understand the dependency pattern and the principles of working of image processing components and structure an inter-connected modelling technique also for those components with the help of mathematical foundation.

  10. Quantitative Phase Imaging Techniques for the Study of Cell Pathophysiology: From Principles to Applications

    Directory of Open Access Journals (Sweden)

    Hyunjoo Park

    2013-03-01

    Full Text Available A cellular-level study of the pathophysiology is crucial for understanding the mechanisms behind human diseases. Recent advances in quantitative phase imaging (QPI techniques show promises for the cellular-level understanding of the pathophysiology of diseases. To provide important insight on how the QPI techniques potentially improve the study of cell pathophysiology, here we present the principles of QPI and highlight some of the recent applications of QPI ranging from cell homeostasis to infectious diseases and cancer.

  11. Multichannel and Multispectral Image Restoration Employing Fuzzy Theory and Directional Techniques

    OpenAIRE

    Rosales, Alberto; Ponomaryov, Volodymyr

    2009-01-01

    It has designed a novel structure of robust framework to remove impulse noise and additive noise in images and multichannel video sequences. Unlike existed techniques, the designed approach employs fuzzy and directional techniques to estimate motion and noise in the past and present frames showing good results. The designed fuzzy rules characterize the presence of motion and noise between the pixels in two frames (past and present frames). It has been demonstrated that the combined use of gra...

  12. Empirical gradient threshold technique for automated segmentation across image modalities and cell lines.

    Science.gov (United States)

    Chalfoun, J; Majurski, M; Peskin, A; Breen, C; Bajcsy, P; Brady, M

    2015-10-01

    New microscopy technologies are enabling image acquisition of terabyte-sized data sets consisting of hundreds of thousands of images. In order to retrieve and analyze the biological information in these large data sets, segmentation is needed to detect the regions containing cells or cell colonies. Our work with hundreds of large images (each 21,000×21,000 pixels) requires a segmentation method that: (1) yields high segmentation accuracy, (2) is applicable to multiple cell lines with various densities of cells and cell colonies, and several imaging modalities, (3) can process large data sets in a timely manner, (4) has a low memory footprint and (5) has a small number of user-set parameters that do not require adjustment during the segmentation of large image sets. None of the currently available segmentation methods meet all these requirements. Segmentation based on image gradient thresholding is fast and has a low memory footprint. However, existing techniques that automate the selection of the gradient image threshold do not work across image modalities, multiple cell lines, and a wide range of foreground/background densities (requirement 2) and all failed the requirement for robust parameters that do not require re-adjustment with time (requirement 5). We present a novel and empirically derived image gradient threshold selection method for separating foreground and background pixels in an image that meets all the requirements listed above. We quantify the difference between our approach and existing ones in terms of accuracy, execution speed, memory usage and number of adjustable parameters on a reference data set. This reference data set consists of 501 validation images with manually determined segmentations and image sizes ranging from 0.36 Megapixels to 850 Megapixels. It includes four different cell lines and two image modalities: phase contrast and fluorescent. Our new technique, called Empirical Gradient Threshold (EGT), is derived from this reference

  13. Microscopy Techniques for Topography Image Acquisition of Marks on Cartridge Cases

    Directory of Open Access Journals (Sweden)

    Milan Navrátil

    2016-11-01

    Full Text Available Despite very high importance of tool mark analysis in criminalistics domain, the image acquisition and comparison of tool marks remains a difficult and time-consuming effort. This work deals with description of selected microscopy techniques applied to examination of marks on the surface of fired cartridge cases, specifically on marks after firing pin. They are represented by 3-D topography images (scanning probe microscopy and laser scanning confocal microscopy and 2-D images (scanning electron microscopy and light microscopy in bright field.

  14. Use of Imaging Techniques in Inflammatory Bowel Diseases That Minimize Radiation Exposure.

    Science.gov (United States)

    Civitelli, Fortunata; Casciani, Emanuele; Maccioni, Francesca; Oliva, Salvatore; Al Ansari, Naiwa; Bonocore, Valeria; Cucchiara, Salvatore

    2015-07-01

    The use of imaging in the management of inflammatory bowel disease (IBD) has grown exponentially in the last few years. This has raised concerns about the risk of high cumulative level of radiation exposure from medical imaging in IBD patients during their lifetime, especially when the disease begins in pediatric age. Physicians caring for IBD children should be aware of the malignant potential of ionizing radiation and of the availability of alternative radiation-free techniques such as magnetic resonance imaging (MRI) and ultrasonography (US), in order to use them whenever possible. This review will focus on the value of US and MRI in pediatric IBD.

  15. A new method for measurement of femoral anteversion using 3D imaging technique

    International Nuclear Information System (INIS)

    Kim, S.I.; Lee, Y.H.; Park, S.-B.; Lee, K.-M.

    1996-01-01

    Conventional methods that use cross-sectional computed tomography (CT) images to estimate femoral anteversion have several problems because of the complex 3 dimensional structure of the femur. These are the ambiguity of defining the femoral neck axis and condylar line, and the dependence on patient positioning. Especially, the femoral neck axis that is known as a major source of error is hard to determine from a single or multiple 2-dimensional transverse CT images. In this study, we are presenting a new method that we have devised form the measurement of femoral anteversion by utilizing the 3 dimensional imaging technique. Poster 176. (author)

  16. Investigating the Role of Global Histogram Equalization Technique for99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement.

    Science.gov (United States)

    Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

    2017-01-01

    99m Technetium-methylene diphosphonate ( 99m Tc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99m Tc-MDP-bone scan images. A set of 89 low contrast 99m Tc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t -test was applied, and a statistically significant difference in the input and processed image quality was found at P histogram equalization technique in combination with some other postprocessing technique is useful.

  17. Characterization of Polycrystalline Materials Using Synchrotron X-ray Imaging and Diffraction Techniques

    DEFF Research Database (Denmark)

    Ludwig, Wolfgang; King, A.; Herbig, M.

    2010-01-01

    propagation based phase contrast imaging, a 3-D imaging mode exploiting the coherence properties of third generation synchrotron beams. Furthermore, for some classes of polycrystalline materials, one may use a 3-D variant of x-ray diffraction imaging, termed x-ray diffraction contrast tomography. X-ray......The combination of synchrotron radiation x-ray imaging and diffraction techniques offers new possibilities for in-situ observation of deformation and damage mechanisms in the bulk of polycrystalline materials. Minute changes in electron density (i.e., cracks, porosities) can be detected using...... diffraction contrast tomography provides access to the 3-D shape, orientation, and elastic strain state of the individual grains from polycrystalline sample volumes containing up to thousand grains. Combining both imaging modalities, one obtains a comprehensive description of the materials microstructure...

  18. A simple noniterative principal component technique for rapid noise reduction in parallel MR images.

    Science.gov (United States)

    Patel, Anand S; Duan, Qi; Robson, Philip M; McKenzie, Charles A; Sodickson, Daniel K

    2012-01-01

    The utilization of parallel imaging permits increased MR acquisition speed and efficiency; however, parallel MRI usually leads to a deterioration in the signal-to-noise ratio when compared with otherwise equivalent unaccelerated acquisitions. At high accelerations, the parallel image reconstruction matrix tends to become dominated by one principal component. This has been utilized to enable substantial reductions in g-factor-related noise. A previously published technique achieved noise reductions via a computationally intensive search for multiples of the dominant singular vector which, when subtracted from the image, minimized joint entropy between the accelerated image and a reference image. We describe a simple algorithm that can accomplish similar results without a time-consuming search. Significant reductions in g-factor-related noise were achieved using this new algorithm with in vivo acquisitions at 1.5 T with an eight-element array. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Characterization of Polycrystalline Materials Using Synchrotron X-ray Imaging and Diffraction Techniques

    DEFF Research Database (Denmark)

    Ludwig, Wolfgang; King, A.; Herbig, M.

    2010-01-01

    The combination of synchrotron radiation x-ray imaging and diffraction techniques offers new possibilities for in-situ observation of deformation and damage mechanisms in the bulk of polycrystalline materials. Minute changes in electron density (i.e., cracks, porosities) can be detected using...... propagation based phase contrast imaging, a 3-D imaging mode exploiting the coherence properties of third generation synchrotron beams. Furthermore, for some classes of polycrystalline materials, one may use a 3-D variant of x-ray diffraction imaging, termed x-ray diffraction contrast tomography. X......-ray diffraction contrast tomography provides access to the 3-D shape, orientation, and elastic strain state of the individual grains from polycrystalline sample volumes containing up to thousand grains. Combining both imaging modalities, one obtains a comprehensive description of the materials microstructure...

  20. High performance optical encryption based on computational ghost imaging with QR code and compressive sensing technique

    Science.gov (United States)

    Zhao, Shengmei; Wang, Le; Liang, Wenqiang; Cheng, Weiwen; Gong, Longyan

    2015-10-01

    In this paper, we propose a high performance optical encryption (OE) scheme based on computational ghost imaging (GI) with QR code and compressive sensing (CS) technique, named QR-CGI-OE scheme. N random phase screens, generated by Alice, is a secret key and be shared with its authorized user, Bob. The information is first encoded by Alice with QR code, and the QR-coded image is then encrypted with the aid of computational ghost imaging optical system. Here, measurement results from the GI optical system's bucket detector are the encrypted information and be transmitted to Bob. With the key, Bob decrypts the encrypted information to obtain the QR-coded image with GI and CS techniques, and further recovers the information by QR decoding. The experimental and numerical simulated results show that the authorized users can recover completely the original image, whereas the eavesdroppers can not acquire any information about the image even the eavesdropping ratio (ER) is up to 60% at the given measurement times. For the proposed scheme, the number of bits sent from Alice to Bob are reduced considerably and the robustness is enhanced significantly. Meantime, the measurement times in GI system is reduced and the quality of the reconstructed QR-coded image is improved.