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Sample records for advanced imaging technique

  1. Advanced radiographic imaging techniques.

    NASA Technical Reports Server (NTRS)

    Beal, J. B.; Brown, R. L.

    1973-01-01

    Examination of the nature and operational constraints of conventional X-radiographic and neutron imaging methods, providing a foundation for a discussion of advanced radiographic imaging systems. Two types of solid-state image amplifiers designed to image X rays are described. Operational theory, panel construction, and performance characteristics are discussed. A closed-circuit television system for imaging neutrons is then described and the system design, operational theory, and performance characteristics are outlined. Emphasis is placed on a description of the advantages of these imaging systems over conventional methods.

  2. Advanced Optical Imaging Techniques for Neurodevelopment

    PubMed Central

    Wu, Yicong; Christensen, Ryan; Colón-Ramos, Daniel; Shroff, Hari

    2013-01-01

    Over the past decade, developmental neuroscience has been transformed by the widespread application of confocal and two-photon fluorescence microscopy. Even greater progress is imminent, as recent innovations in microscopy now enable imaging with increased depth, speed, and spatial resolution; reduced phototoxicity; and in some cases without external fluorescent probes. We discuss these new techniques and emphasize their dramatic impact on neurobiology, including the ability to image neurons at depths exceeding 1 mm, to observe neurodevelopment noninvasively throughout embryogenesis, and to visualize neuronal processes or structures that were previously too small or too difficult to target with conventional microscopy. PMID:23831260

  3. The Advanced Space Plant Culture Device with Live Imaging Technique

    NASA Astrophysics Data System (ADS)

    Zheng, Weibo; Zhang, Tao; Tong, Guanghui

    The live imaging techniques, including the color and fluorescent imags, are very important and useful for space life science. The advanced space plant culture Device (ASPCD) with live imaging Technique, developed for Chinese Spacecraft, would be introduced in this paper. The ASPCD had two plant experimental chambers. Three cameras (two color cameras and one fluorescent camera) were installed in the two chambers. The fluorescent camera could observe flowering genes, which were labeled by GFP. The lighting, nutrient, temperature controling and water recycling were all independent in each chamber. The ASPCD would beed applied to investigate for the growth and development of the high plant under microgravity conditions on board the Chinese Spacecraft.

  4. Recent Advances in Techniques for Hyperspectral Image Processing

    NASA Technical Reports Server (NTRS)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; Marconcini, Mattia; Tilton, James C.; Trianni, Giovanna

    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

  5. Advanced imaging techniques for the detection of breast cancer.

    PubMed

    Jochelson, Maxine

    2012-01-01

    Mammography is the only breast imaging examination that has been shown to reduce breast cancer mortality. Population-based sensitivity is 75% to 80%, but sensitivity in high-risk women with dense breasts is only in the range of 50%. Breast ultrasound and contrast-enhanced breast magnetic resonance imaging (MRI) have become additional standard modalities used in the diagnosis of breast cancer. In high-risk women, ultrasound is known to detect approximately four additional cancers per 1,000 women. MRI is exquisitely sensitive for the detection of breast cancer. In high-risk women, it finds an additional four to five cancers per 100 women. However, both ultrasound and MRI are also known to lead to a large number of additional benign biopsies and short-term follow-up examinations. Many new breast imaging tools have improved and are being developed to improve on our current ability to diagnose early-stage breast cancer. These can be divided into two groups. The first group is those that are advances in current techniques, which include digital breast tomosynthesis and contrast-enhanced mammography and ultrasound with elastography or microbubbles. The other group includes new breast imaging platforms such as breast computed tomography (CT) scanning and radionuclide breast imaging. These are exciting advances. However, in this era of cost and radiation containment, it is imperative to look at all of them objectively to see which will provide clinically relevant additional information. PMID:24451711

  6. Advanced Diffusion-Weighted Magnetic Resonance Imaging Techniques of the Human Spinal Cord

    PubMed Central

    Andre, Jalal B.; Bammer, Roland

    2012-01-01

    Unlike those of the brain, advances in diffusion-weighted imaging (DWI) of the human spinal cord have been challenged by the more complicated and inhomogeneous anatomy of the spine, the differences in magnetic susceptibility between adjacent air and fluid-filled structures and the surrounding soft tissues, and the inherent limitations of the initially used echo-planar imaging techniques used to image the spine. Interval advances in DWI techniques for imaging the human spinal cord, with the specific aims of improving the diagnostic quality of the images, and the simultaneous reduction in unwanted artifacts have resulted in higher-quality images that are now able to more accurately portray the complicated underlying anatomy and depict pathologic abnormality with improved sensitivity and specificity. Diffusion tensor imaging (DTI) has benefited from the advances in DWI techniques, as DWI images form the foundation for all tractography and DTI. This review provides a synopsis of the many recent advances in DWI of the human spinal cord, as well as some of the more common clinical uses for these techniques, including DTI and tractography. PMID:22158130

  7. Advanced Computer Image Generation Techniques Exploiting Perceptual Characteristics. Final Report.

    ERIC Educational Resources Information Center

    Stenger, Anthony J.; And Others

    This study suggests and identifies computer image generation (CIG) algorithms for visual simulation that improve the training effectiveness of CIG simulators and identifies areas of basic research in visual perception that are significant for improving CIG technology. The first phase of the project entailed observing three existing CIG simulators.…

  8. Automated angiogenesis quantification through advanced image processing techniques.

    PubMed

    Doukas, Charlampos N; Maglogiannis, Ilias; Chatziioannou, Aristotle; Papapetropoulos, Andreas

    2006-01-01

    Angiogenesis, the formation of blood vessels in tumors, is an interactive process between tumor, endothelial and stromal cells in order to create a network for oxygen and nutrients supply, necessary for tumor growth. According to this, angiogenic activity is considered a suitable method for both tumor growth or inhibition detection. The angiogenic potential is usually estimated by counting the number of blood vessels in particular sections. One of the most popular assay tissues to study the angiogenesis phenomenon is the developing chick embryo and its chorioallantoic membrane (CAM), which is a highly vascular structure lining the inner surface of the egg shell. The aim of this study was to develop and validate an automated image analysis method that would give an unbiased quantification of the micro-vessel density and growth in angiogenic CAM images. The presented method has been validated by comparing automated results to manual counts over a series of digital chick embryo photos. The results indicate the high accuracy of the tool, which has been thus extensively used for tumor growth detection at different stages of embryonic development. PMID:17946107

  9. Advanced spatio-temporal filtering techniques for photogrammetric image sequence analysis in civil engineering material testing

    NASA Astrophysics Data System (ADS)

    Liebold, F.; Maas, H.-G.

    2016-01-01

    The paper shows advanced spatial, temporal and spatio-temporal filtering techniques which may be used to reduce noise effects in photogrammetric image sequence analysis tasks and tools. As a practical example, the techniques are validated in a photogrammetric spatio-temporal crack detection and analysis tool applied in load tests in civil engineering material testing. The load test technique is based on monocular image sequences of a test object under varying load conditions. The first image of a sequence is defined as a reference image under zero load, wherein interest points are determined and connected in a triangular irregular network structure. For each epoch, these triangles are compared to the reference image triangles to search for deformations. The result of the feature point tracking and triangle comparison process is a spatio-temporally resolved strain value field, wherein cracks can be detected, located and measured via local discrepancies. The strains can be visualized as a color-coded map. In order to improve the measuring system and to reduce noise, the strain values of each triangle must be treated in a filtering process. The paper shows the results of various filter techniques in the spatial and in the temporal domain as well as spatio-temporal filtering techniques applied to these data. The best results were obtained by a bilateral filter in the spatial domain and by a spatio-temporal EOF (empirical orthogonal function) filtering technique.

  10. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder

    PubMed Central

    Kremer, Stephane; Renard, Felix; Achard, Sophie; Lana-Peixoto, Marco A.; Palace, Jacqueline; Asgari, Nasrin; Klawiter, Eric C.; Tenembaum, Silvia N.; Banwell, Brenda; Greenberg, Benjamin M.; Bennett, Jeffrey L.; Levy, Michael; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Chan, Koon Ho; Schippling, Sven; Paul, Friedemann; Kim, Ho Jin; de Seze, Jerome; Wuerfel, Jens T.

    2016-01-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease. PMID:26010909

  11. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder.

    PubMed

    Kremer, Stephane; Renard, Felix; Achard, Sophie; Lana-Peixoto, Marco A; Palace, Jacqueline; Asgari, Nasrin; Klawiter, Eric C; Tenembaum, Silvia N; Banwell, Brenda; Greenberg, Benjamin M; Bennett, Jeffrey L; Levy, Michael; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Chan, Koon Ho; Schippling, Sven; Paul, Friedemann; Kim, Ho Jin; de Seze, Jerome; Wuerfel, Jens T; Cabre, Philippe; Marignier, Romain; Tedder, Thomas; van Pelt, Danielle; Broadley, Simon; Chitnis, Tanuja; Wingerchuk, Dean; Pandit, Lekha; Leite, Maria Isabel; Apiwattanakul, Metha; Kleiter, Ingo; Prayoonwiwat, Naraporn; Han, May; Hellwig, Kerstin; van Herle, Katja; John, Gareth; Hooper, D Craig; Nakashima, Ichiro; Sato, Douglas; Yeaman, Michael R; Waubant, Emmanuelle; Zamvil, Scott; Stüve, Olaf; Aktas, Orhan; Smith, Terry J; Jacob, Anu; O'Connor, Kevin

    2015-07-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease. PMID:26010909

  12. Updates in advanced diffusion-weighted magnetic resonance imaging techniques in the evaluation of prostate cancer

    PubMed Central

    Vargas, Hebert Alberto; Lawrence, Edward Malnor; Mazaheri, Yousef; Sala, Evis

    2015-01-01

    Diffusion-weighted magnetic resonance imaging (DW-MRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer. It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DW-MRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the non-mono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging (DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer. PMID:26339460

  13. Advanced imaging techniques II: using a compound microscope for photographing point-mount specimens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Digital imaging technology has revolutionized the practice photographing insects for scientific study. Herein described are lighting and mounting techniques designed for imaging micro Hymenoptera. Techniques described here are applicable to all small insects, as well as other invertebrates. The ke...

  14. Advanced imaging techniques for the study of plant growth and development

    PubMed Central

    Sozzani, Rosangela; Busch, Wolfgang; Spalding, Edgar P.; Benfey, Philip N.

    2014-01-01

    A variety of imaging methodologies are being used to collect data for quantitative studies of plant growth and development from living plants. Multi-level data, from macroscopic to molecular, and from weeks to seconds, can be acquired. Furthermore, advances in parallelized and automated image acquisition enable the throughput to capture images from large populations of plants under specific growth conditions. Image-processing capabilities allow for 3D or 4D reconstruction of image data and automated quantification of biological features. These advances facilitate the integration of imaging data with genome-wide molecular data to enable systems-level modeling. PMID:24434036

  15. Advances in Image Processing Techniques for Drusens Detection and Quantification in Fundus Images

    NASA Astrophysics Data System (ADS)

    Mora, André; Vieira, Pedro; Fonseca, José

    Age-Related Macular Degeneration (ARMD) is considered the leading cause of irreversible blindness in developed countries. One of its risk factors is the presence of drusens, which are retina abnormalities appearing as yellowish spots in fundus images.

  16. EPS in Environmental Microbial Biofilms as Examined by Advanced Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Neu, T. R.; Lawrence, J. R.

    2006-12-01

    Biofilm communities are highly structured associations of cellular and polymeric components which are involved in biogenic and geogenic environmental processes. Furthermore, biofilms are also important in medical (infection), industrial (biofouling) and technological (biofilm engineering) processes. The interfacial microbial communities in a specific habitat are highly dynamic and change according to the environmental parameters affecting not only the cellular but also the polymeric constituents of the system. Through their EPS biofilms interact with dissolved, colloidal and particulate compounds from the bulk water phase. For a long time the focus in biofilm research was on the cellular constituents in biofilms and the polymer matrix in biofilms has been rather neglected. The polymer matrix is produced not only by different bacteria and archaea but also by eukaryotic micro-organisms such as algae and fungi. The mostly unidentified mixture of EPS compounds is responsible for many biofilm properties and is involved in biofilm functionality. The chemistry of the EPS matrix represents a mixture of polymers including polysaccharides, proteins, nucleic acids, neutral polymers, charged polymers, amphiphilic polymers and refractory microbial polymers. The analysis of the EPS may be done destructively by means of extraction and subsequent chemical analysis or in situ by means of specific probes in combination with advanced imaging. In the last 15 years laser scanning microscopy (LSM) has been established as an indispensable technique for studying microbial communities. LSM with 1-photon and 2-photon excitation in combination with fluorescence techniques allows 3-dimensional investigation of fully hydrated, living biofilm systems. This approach is able to reveal data on biofilm structural features as well as biofilm processes and interactions. The fluorescent probes available allow the quantitative assessment of cellular as well as polymer distribution. For this purpose

  17. Advanced 3D-Sonographic Imaging as a Precise Technique to Evaluate Tumor Volume

    PubMed Central

    Pflanzer, R.; Hofmann, M.; Shelke, A.; Habib, A.; Derwich, W.; Schmitz-Rixen, T.; Bernd, A.; Kaufmann, R.; Bereiter-Hahn, J.

    2014-01-01

    Determination of tumor volume in subcutaneously inoculated xenograft models is a standard procedure for clinical and preclinical evaluation of tumor response to treatment. Practitioners frequently use a hands-on caliper method in conjunction with a simplified formula to assess tumor volume. Non-invasive and more precise techniques as investigation by MR or (μ)CT exist but come with various adverse effects in terms of radiation, complex setup or elevated cost of investigations. Therefore, we propose an advanced three-dimensional sonographic imaging technique to determine small tumor volumes in xenografts with high precision and minimized observer variability. We present a study on xenograft carcinoma tumors from which volumes and shapes were calculated with the standard caliper method as well as with a clinically available three-dimensional ultrasound scanner and subsequent processing software. Statistical analysis reveals the suitability of this non-invasive approach for the purpose of a quick and precise calculation of tumor volume in small rodents. PMID:25500076

  18. Integration of patient specific modeling and advanced image processing techniques for image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

    Archip, Neculai; Fedorov, Andriy; Lloyd, Bryn; Chrisochoides, Nikos; Golby, Alexandra; Black, Peter M.; Warfield, Simon K.

    2006-03-01

    A major challenge in neurosurgery oncology is to achieve maximal tumor removal while avoiding postoperative neurological deficits. Therefore, estimation of the brain deformation during the image guided tumor resection process is necessary. While anatomic MRI is highly sensitive for intracranial pathology, its specificity is limited. Different pathologies may have a very similar appearance on anatomic MRI. Moreover, since fMRI and diffusion tensor imaging are not currently available during the surgery, non-rigid registration of preoperative MR with intra-operative MR is necessary. This article presents a translational research effort that aims to integrate a number of state-of-the-art technologies for MRI-guided neurosurgery at the Brigham and Women's Hospital (BWH). Our ultimate goal is to routinely provide the neurosurgeons with accurate information about brain deformation during the surgery. The current system is tested during the weekly neurosurgeries in the open magnet at the BWH. The preoperative data is processed, prior to the surgery, while both rigid and non-rigid registration algorithms are run in the vicinity of the operating room. The system is tested on 9 image datasets from 3 neurosurgery cases. A method based on edge detection is used to quantitatively validate the results. 95% Hausdorff distance between points of the edges is used to estimate the accuracy of the registration. Overall, the minimum error is 1.4 mm, the mean error 2.23 mm, and the maximum error 3.1 mm. The mean ratio between brain deformation estimation and rigid alignment is 2.07. It demonstrates that our results can be 2.07 times more precise then the current technology. The major contribution of the presented work is the rigid and non-rigid alignment of the pre-operative fMRI with intra-operative 0.5T MRI achieved during the neurosurgery.

  19. Advances in functional X-ray imaging techniques and contrast agents

    PubMed Central

    Chen, Hongyu; Rogalski, Melissa M.

    2012-01-01

    X-rays have been used for non-invasive high-resolution imaging of thick biological specimens since their discovery in 1895. They are widely used for structural imaging of bone, metal implants, and cavities in soft tissue. Recently, a number of new contrast methodologies have emerged which are expanding X-ray’s biomedical applications to functional as well as structural imaging. These techniques are promising to dramatically improve our ability to study in situ biochemistry and disease pathology. In this review, we discuss how X-ray absorption, X-ray fluorescence, and X-ray excited optical luminescence can be used for physiological, elemental, and molecular imaging of vasculature, tumours, pharmaceutical distribution, and the surface of implants. Imaging of endogenous elements, exogenous labels, and analytes detected with optical indicators will be discussed. PMID:22962667

  20. A standard data set for performance analysis of advanced IR image processing techniques

    NASA Astrophysics Data System (ADS)

    Weiß, A. Robert; Adomeit, Uwe; Chevalier, Philippe; Landeau, Stéphane; Bijl, Piet; Champagnat, Frédéric; Dijk, Judith; Göhler, Benjamin; Landini, Stefano; Reynolds, Joseph P.; Smith, Leslie N.

    2012-06-01

    Modern IR cameras are increasingly equipped with built-in advanced (often non-linear) image and signal processing algorithms (like fusion, super-resolution, dynamic range compression etc.) which can tremendously influence performance characteristics. Traditional approaches to range performance modeling are of limited use for these types of equipment. Several groups have tried to overcome this problem by producing a variety of imagery to assess the impact of advanced signal and image processing. Mostly, this data was taken from classified targets and/ or using classified imager and is thus not suitable for comparison studies between different groups from government, industry and universities. To ameliorate this situation, NATO SET-140 has undertaken a systematic measurement campaign at the DGA technical proving ground in Angers, France, to produce an openly distributable data set suitable for the assessment of fusion, super-resolution, local contrast enhancement, dynamic range compression and image-based NUC algorithm performance. The imagery was recorded for different target / background settings, camera and/or object movements and temperature contrasts. MWIR, LWIR and Dual-band cameras were used for recording and were also thoroughly characterized in the lab. We present a selection of the data set together with examples of their use in the assessment of super-resolution and contrast enhancement algorithms.

  1. Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma.

    PubMed

    Yang, Ke; Zhang, Xiao-Ming; Yang, Lin; Xu, Hao; Peng, Juan

    2016-05-28

    Hepatocellular carcinoma (HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization (TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusion-weighted magnetic resonance imaging (MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusion-weighted imaging, blood oxygen level-dependent MRI, positron emission tomography (PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed. PMID:27239110

  2. Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma

    PubMed Central

    Yang, Ke; Zhang, Xiao-Ming; Yang, Lin; Xu, Hao; Peng, Juan

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization (TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusion-weighted magnetic resonance imaging (MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusion-weighted imaging, blood oxygen level-dependent MRI, positron emission tomography (PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed. PMID:27239110

  3. Advanced magnetic resonance imaging techniques in the preterm brain: methods and applications.

    PubMed

    Tao, Joshua D; Neil, Jeffrey J

    2014-01-01

    Brain development and brain injury in preterm infants are areas of active research. Magnetic resonance imaging (MRI), a non-invasive tool applicable to both animal models and human infants, provides a wealth of information on this process by bridging the gap between histology (available from animal studies) and developmental outcome (available from clinical studies). Moreover, MRI also offers information regarding diagnosis and prognosis in the clinical setting. Recent advances in MR methods - diffusion tensor imaging, volumetric segmentation, surface based analysis, functional MRI, and quantitative metrics - further increase the sophistication of information available regarding both brain structure and function. In this review, we discuss the basics of these newer methods as well as their application to the study of premature infants. PMID:25055864

  4. Advanced data visualization and sensor fusion: Conversion of techniques from medical imaging to Earth science

    NASA Technical Reports Server (NTRS)

    Savage, Richard C.; Chen, Chin-Tu; Pelizzari, Charles; Ramanathan, Veerabhadran

    1993-01-01

    Hughes Aircraft Company and the University of Chicago propose to transfer existing medical imaging registration algorithms to the area of multi-sensor data fusion. The University of Chicago's algorithms have been successfully demonstrated to provide pixel by pixel comparison capability for medical sensors with different characteristics. The research will attempt to fuse GOES (Geostationary Operational Environmental Satellite), AVHRR (Advanced Very High Resolution Radiometer), and SSM/I (Special Sensor Microwave Imager) sensor data which will benefit a wide range of researchers. The algorithms will utilize data visualization and algorithm development tools created by Hughes in its EOSDIS (Earth Observation SystemData/Information System) prototyping. This will maximize the work on the fusion algorithms since support software (e.g. input/output routines) will already exist. The research will produce a portable software library with documentation for use by other researchers.

  5. Visualization of delamination in composite materials utilizing advanced X-ray imaging techniques

    NASA Astrophysics Data System (ADS)

    Vavrik, D.; Jakubek, J.; Jandejsek, I.; Krejci, F.; Kumpova, I.; Zemlicka, J.

    2015-04-01

    This work is focused on the development of instrumental radiographic methods for detection of delaminations in layered carbon fibre reinforced plastic composites used in the aerospace industry. The main limitation of current visualisation techniques is a very limited possibility to image so-called closed delaminations in which delaminated layers are in contact practically with no physical gap. In this contribution we report the development of innovative methods for closed delamination detection using an X-ray phase contrast technique for which the distance between delamination surfaces is not relevant. The approach is based on the energetic sensitivity of phase-enhanced radiography. Based on the applied methodology, we can distinguish both closed and open delamination. Further we have demonstrated the possibility to visualise open delaminations characterised by a physical gap between delaminated layers. This delamination type was successfully identified and visualized utilizing a high resolution and computed tomography table-top technique based on proper beam-hardening effect correction.

  6. Advanced, time-resolved imaging techniques for electron-beam characterizations

    SciTech Connect

    Lumpkin, A.H.

    1990-01-01

    Several unique time-resolved imaging techniques have been developed to address radio frequency (RF)-linac generated electron beams and the free-electron lasers (FEL) driven by such systems. The time structures of these beams involve a series of micropulses with 10 to 15-ps duration, separated by tens of nanoseconds. Mechanisms to convert the e-beam information to optical radiation include optical transition radiation (OTR), Cherenkov radiation, spontaneous emission radiation (SER), and the FEL mechanism itself. The use of gated, intensified television cameras and synchroscan and dual-sweep streak cameras to time-resolve these signals has greatly enhanced the power of these techniques. A brief review of the less familiar conversion mechanisms and electro-optic techniques is followed by a series of specific experimental examples from the RF linac FEL facilities at Los Alamos and Boeing (Seattle, WA). 23 refs., 35 figs., 3 tabs.

  7. An Insight into Lüders Deformation Using Advanced Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Nagarajan, Srinivasan; Narayanaswamy, Raghu; Balasubramaniam, Venkatraman

    2013-10-01

    An investigation to explore the feasibility of simultaneous application of infrared thermography (IRT) and digital image correlation (DIC) for analysis of Lüders deformation is carried out. Physical models and proposed concepts explaining the dynamics of deformation localization associated with Lüders band phenomenon addressing band-formation mechanism, inhomogeneity in stress-strain distribution across the band front, and strain localization following band front propagation are successfully correlated with the thermal and strain evolutions obtained using IRT and DIC. The studies revealed the potential of using these techniques simultaneously in providing an enhanced understanding of micro mechanisms involved in Lüders deformation based on associated macroscopic thermal and strain evolutions in a noncontact, nondestructive manner.

  8. Use of advanced imaging techniques during visits to emergency departments-implications, costs, patient benefits/risks.

    PubMed

    Dick, Elizabeth A; Varma, Dinesh; Kashef, Elika; Curtis, John

    2016-05-01

    25 years ago, on a Friday evening at 9 pm, the emergency department (ED) was full of patients with a wide range of clinical problems. Their investigations included plain radiographs, but no other imaging was included until the next working day. At present, many patients are receiving advanced imaging such as ultrasound, CT and MRI, often delivered out of hours-an obvious advance for patients or sometimes an unnecessary development? In this article, we will consider how to assess patient benefits and whether increased use of advanced imaging is an overall advance for patients. We will address the general implications for healthcare services which come with greater use of advanced imaging. We will then address the effect of advanced imaging on individual fictional ED patients with a variety of complaints. PMID:26693970

  9. Comparison of advanced optical imaging techniques with current otolaryngology diagnostics for improved middle ear assessment (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Nolan, Ryan M.; Shelton, Ryan L.; Monroy, Guillermo L.; Spillman, Darold R.; Novak, Michael A.; Boppart, Stephen A.

    2016-02-01

    Otolaryngologists utilize a variety of diagnostic techniques to assess middle ear health. Tympanometry, audiometry, and otoacoustic emissions examine the mobility of the tympanic membrane (eardrum) and ossicles using ear canal pressure and auditory tone delivery and detection. Laser Doppler vibrometry provides non-contact vibrational measurement, and acoustic reflectometry is used to assess middle ear effusion using sonar. These technologies and techniques have advanced the field beyond the use of the standard otoscope, a simple tissue magnifier, yet the need for direct visualization of middle ear disease for superior detection, assessment, and management remains. In this study, we evaluated the use of portable optical coherence tomography (OCT) and pneumatic low-coherence interferometry (LCI) systems with handheld probe delivery to standard tympanometry, audiometry, otoacoustic emissions, laser Doppler vibrometry, and acoustic reflectometry. Comparison of these advanced optical imaging techniques and current diagnostics was conducted with a case study subject with a history of unilateral eardrum trauma. OCT and pneumatic LCI provide novel dynamic spatiotemporal structural data of the middle ear, such as the thickness of the eardrum and quantitative detection of underlying disease pathology, which could allow for more accurate diagnosis and more appropriate management than currently possible.

  10. Pediatric Cerebellar Tumors: Emerging Imaging Techniques and Advances in Understanding of Genetic Features.

    PubMed

    Choudhri, Asim F; Siddiqui, Adeel; Klimo, Paul

    2016-08-01

    Cerebellar tumors are the most common group of solid tumors in children. MR imaging provides an important role in characterization of these lesions, surgical planning, and postsurgical surveillance. Preoperative imaging can help predict the histologic subtype of tumors, which can provide guidance for surgical planning. Beyond histology, pediatric brain tumors are undergoing new classification schemes based on genetic features. Intraoperative MR imaging has emerged as an important tool in the surgical management of pediatric brain tumors. Effective understanding of the imaging features of pediatric cerebellar tumors can benefit communication with neurosurgeons and neuro-oncologists and can improve patient management. PMID:27423803

  11. Advanced data readout technique for Multianode Position Sensitive Photomultiplier Tube applicable in radiation imaging detectors

    SciTech Connect

    V. Popov

    2011-01-01

    Most of the best performing PSPMT tubes from Hamamatsu and Burle are designed with a pad-matrix anode layout. However, for obtaining a high resolution, a small-sized anode photomultiplier tubes are preferable; these tubes may have 64, 256 or 1024 anodes per tube. If the tubes are used in array to get a larger area detector, the number of analog channels may range from hundreds to thousands. Multichannel analog readout requires special electronics ICs, ASICs etc., which are attached to multichannel DAQ system. As a result, the data file and data processing time will be increased. Therefore, this readout could not be performed in a small project. Usually, most of radiation imaging applications allow the use of analog data processing in front-end electronics, significantly reducing the number of the detector's output lines to data acquisition without reducing the image quality. The idea of pad-matrix decoupling circuit with gain correction was invented and intensively tested in JLab. Several versions of PSPMT readout electronics were produced and studied. All developments were done and optimized specifically for radiation imaging projects. They covered high resolution SPECT, high speed PET, fast neutron imaging, and single tube and multi tube array systems. This paper presents and discusses the summary of the observed results in readout electronics evaluation with different PSPMTs and radiation imaging systems, as well as the advantages and limitations of the developed approach to radiation imaging detectors readout.

  12. Advanced Magnetic Resonance Imaging techniques to probe muscle structure and function

    NASA Astrophysics Data System (ADS)

    Malis, Vadim

    Structural and functional Magnetic Resonance Imaging (MRI) studies of skeletal muscle allow the elucidation of muscle physiology under normal and pathological conditions. Continuing on the efforts of the Muscle Imaging and Modeling laboratory, the focus of the thesis is to (i) extend and refine two challenging imaging modalities: structural imaging using Diffusion Tensor Imaging (DTI) and functional imaging based on Velocity Encoded Phase Contrast Imaging (VE-PC) and (ii) apply these methods to explore age related structure and functional differences of the gastrocnemius muscle. Diffusion Tensor Imaging allows the study of tissue microstructure as well as muscle fiber architecture. The images, based on an ultrafast single shot Echo Planar Imaging (EPI) sequence, suffer from geometric distortions and low signal to noise ratio. A processing pipeline was developed to correct for distortions and to improve image Signal to Noise Ratio (SNR). DTI acquired on a senior and young cohort of subjects were processed through the pipeline and differences in DTI derived indices and fiber architecture between the two cohorts were explored. The DTI indices indicated that at the microstructural level, fiber atrophy was accompanied with a reduction in fiber volume fraction. At the fiber architecture level, fiber length and pennation angles decreased with age that potentially contribute to the loss of muscle force with age. Velocity Encoded Phase Contrast imaging provides tissue (e.g. muscle) velocity at each voxel which allows the study of strain and Strain Rate (SR) under dynamic conditions. The focus of the thesis was to extract 2D strain rate tensor maps from the velocity images and apply the method to study age related differences. The tensor mapping can potentially provide unique information on the extracellular matrix and lateral transmission the role of these two elements has recently emerged as important determinants of force loss with age. In the cross sectional study on

  13. Image enhancement and advanced information extraction techniques for ERTS-1 data

    NASA Technical Reports Server (NTRS)

    Malila, W. A. (Principal Investigator); Nalepka, R. F.; Sarno, J. E.

    1975-01-01

    The author has identified the following significant results. It was demonstrated and concluded that: (1) the atmosphere has significant effects on ERTS MSS data which can seriously degrade recognition performance; (2) the application of selected signature extension techniques serve to reduce the deleterious effects of both the atmosphere and changing ground conditions on recognition performance; and (3) a proportion estimation algorithm for overcoming problems in acreage estimation accuracy resulting from the coarse spatial resolution of the ERTS MSS, was able to significantly improve acreage estimation accuracy over that achievable by conventional techniques, especially for high contrast targets such as lakes and ponds.

  14. High-resolution imaging of hypervelocity metal jets using advanced high-speed photographic techniques

    SciTech Connect

    Shaw, L.L.; Muelder, S.A.

    1995-08-29

    It is now possible to obtain high resolution sequential photographs of the initial formation and evolution of hypervelocity metal jets formed by shaped charge devices fired in air. Researchers have been frustrated by the high velocity of the jet material and the luminous sheath of hot gases cloaking the jet that made detailed observation of the jet body extremely difficult. The camera system that provides the photographs is a large format multi-frame electro-optic camera, referred to as an IC camera (IC stands for image converter), that utilizes electro-optic shuttering, monochromatic pulsed laser illumination and bandpass filtering to provide sequential pictures (in 3D if desired) with minimal degradation due to luminous air shocks or motion blur. The large format (75mm image plane), short exposure (15 ns minimum), ruby laser illumination and bandpass filtering (monochromatic illumination while excluding extraneous light) produces clear, sharp, images of the detailed surface structure of a metal shaped charge jet during early jet formation, elongation of the jet body, jet tip evolution and subsequent particulation (breakup) of the jet body. By utilizing the new camera system in conjunction with the more traditional rotating mirror high speed cameras, pulsed radiography, and electrical sensors, a maximum amount of, often unique, data can be extracted from a single experiment. This paper was intended primarily as an oral presentation. For purposes of continuity and simplicity in these proceedings, the authors have chosen to concentrate on the development of the IC camera system and its impact on the photography of high speed shaped chargejets.

  15. Advances in the diagnosis of acute aortic syndromes: Role of imaging techniques.

    PubMed

    Ciccone, Marco Matteo; Dentamaro, Ilaria; Masi, Filippo; Carbonara, Santa; Ricci, Gabriella

    2016-06-01

    Aortic diseases include a wide range of pathological conditions: aortic aneurysms, pseudoaneurysms, acute aortic syndromes, atherosclerotic and inflammatory conditions, genetic diseases and congenital anomalies. Acute aortic syndromes have acute onset and may be life-threatening. They include aortic dissection, intramural haematoma, penetrating aortic ulcer and traumatic aortic injury. Pain is the common denominator to all acute aortic syndromes. Pain occurs regardless of age, gender and other associated clinical conditions. In this review, we deal with the main findings in the clinical setting and the most recent indications for diagnostic imaging, which are aimed to start an appropriate treatment and improve the short- and long-term prognosis of these patients. PMID:26957573

  16. Advanced data visualization and sensor fusion: Conversion of techniques from medical imaging to Earth science

    NASA Technical Reports Server (NTRS)

    Savage, Richard C.; Chen, Chin-Tu; Pelizzari, Charles; Ramanathan, Veerabhadran

    1992-01-01

    Hughes Aircraft Company and the University of Chicago propose to transfer existing medical imaging registration algorithms to the area of multi-sensor data fusion. The University of Chicago's algorithms have been successfully demonstrated to provide pixel by pixel comparison capability for medical sensors with different characteristics. The research will attempt to fuse GOES, AVHRR, and SSM/I sensor data which will benefit a wide range of researchers. The algorithms will utilize data visualization and algorithm development tools created by Hughes in its EOSDIS prototyping. This will maximize the work on the fusion algorithms since support software (e.g. input/output routines) will already exist. The research will produce a portable software library with documentation for use by other researchers.

  17. Lipid dynamics in boar sperm studied by advanced fluorescence imaging techniques.

    PubMed

    Schröter, Filip; Jakop, Ulrike; Teichmann, Anke; Haralampiev, Ivan; Tannert, Astrid; Wiesner, Burkhard; Müller, Peter; Müller, Karin

    2016-03-01

    The (re)organization of membrane components is of special importance to prepare mammalian sperm to fertilization. Establishing suitable methods to examine physico-chemical membrane parameters is of high interest. We characterized the behavior of fluorescent (NBD) analogs of sphingomyelin (SM), phosphatidylserine (PS), and cholesterol (Ch) in the acrosomal and postacrosomal macrodomain of boar sperm. Due to their specific transverse membrane distribution, a leaflet-specific investigation of membrane properties is possible. The behavior of lipid analogs in boar sperm was investigated by fluorescence lifetime imaging microscopy (FLIM), fluorescence recovery after photobleaching (FRAP), and fluorescence correlation spectroscopy (FCS). The results were compared with regard to the different temporal and spatial resolution of the methods. For the first time, fluorescence lifetimes of lipid analogs were determined in sperm cell membrane and found to be in a range characteristic for the liquid-disordered phase in artificial lipid membranes. FLIM analyses further indicate a more fluid microenvironment of NBD-Ch and NBD-PS in the postacrosomal compared to the acrosomal region. The concept of a more fluid cytoplasmic leaflet is supported by lower fluorescence lifetime and higher average D values (FCS) for NBD-PS in both head compartments. Whereas FLIM analyses did not indicate coexisting distinct liquid-ordered and -disordered domains in any of the head regions, comparisons between FRAP and FCS measurements suggest the incorporation of NBD-SM as well as NBD-PS in postacrosomal subpopulations with different diffusion velocity. The analog-specific results indicate that the lipid analogs used are suitable to report on the various physicochemical properties of different microenvironments. PMID:26481472

  18. Advanced Wavefront Control Techniques

    SciTech Connect

    Olivier, S S; Brase, J M; Avicola, K; Thompson, C A; Kartz, M W; Winters, S; Hartley, R; Wihelmsen, J; Dowla, F V; Carrano, C J; Bauman, B J; Pennington, D M; Lande, D; Sawvel, R M; Silva, D A; Cooke, J B; Brown, C G

    2001-02-21

    Programs at LLNL that involve large laser systems--ranging from the National Ignition Facility to new tactical laser weapons--depend on the maintenance of laser beam quality through precise control of the optical wavefront. This can be accomplished using adaptive optics, which compensate for time-varying aberrations that are often caused by heating in a high-power laser system. Over the past two decades, LLNL has developed a broad capability in adaptive optics technology for both laser beam control and high-resolution imaging. This adaptive optics capability has been based on thin deformable glass mirrors with individual ceramic actuators bonded to the back. In the case of high-power lasers, these adaptive optics systems have successfully improved beam quality. However, as we continue to extend our applications requirements, the existing technology base for wavefront control cannot satisfy them. To address this issue, this project studied improved modeling tools to increase our detailed understanding of the performance of these systems, and evaluated novel approaches to low-order wavefront control that offer the possibility of reduced cost and complexity. We also investigated improved beam control technology for high-resolution wavefront control. Many high-power laser systems suffer from high-spatial-frequency aberrations that require control of hundreds or thousands of phase points to provide adequate correction. However, the cost and size of current deformable mirrors can become prohibitive for applications requiring more than a few tens of phase control points. New phase control technologies are becoming available which offer control of many phase points with small low-cost devices. The goal of this project was to expand our wavefront control capabilities with improved modeling tools, new devices that reduce system cost and complexity, and extensions to high spatial and temporal frequencies using new adaptive optics technologies. In FY 99, the second year of

  19. Modern Imaging Technology: Recent Advances

    SciTech Connect

    Welch, Michael J.; Eckelman, William C.

    2004-06-18

    This 2-day conference is designed to bring scientist working in nuclear medicine, as well as nuclear medicine practitioners together to discuss the advances in four selected areas of imaging: Biochemical Parameters using Small Animal Imaging, Developments in Small Animal PET Imaging, Cell Labeling, and Imaging Angiogenesis Using Multiple Modality. The presentations will be on molecular imaging applications at the forefront of research, up to date on the status of molecular imaging in nuclear medicine as well as in related imaging areas. Experts will discuss the basic science of imaging techniques, and scheduled participants will engage in an exciting program that emphasizes the current status of molecular imaging as well as the role of DOE funded research in this area.

  20. MR enterography in Crohn's disease: current consensus on optimal imaging technique and future advances from the SAR Crohn's disease-focused panel.

    PubMed

    Grand, David J; Guglielmo, Flavius F; Al-Hawary, Mahmoud M

    2015-06-01

    MR enterography is a powerful tool for the non-invasive evaluation of patients with Crohn's disease (CD) without ionizing radiation. The following paper describes the current consensus on optimal imaging technique, interpretation, and future advances from the Society of Abdominal Radiology CD-focused panel. PMID:25666967

  1. [Advance in imaging spectropolarimeter].

    PubMed

    Wang, Xin-quan; Xiangli, Bin; Huang, Min; Hu, Liang; Zhou, Jin-song; Jing, Juan-juan

    2011-07-01

    Imaging spectropolarimeter (ISP) is a type of novel photoelectric sensor which integrated the functions of imaging, spectrometry and polarimetry. In the present paper, the concept of the ISP is introduced, and the advances in ISP at home and abroad in recent years is reviewed. The principles of ISPs based on novel devices, such as acousto-optic tunable filter (AOTF) and liquid crystal tunable filter (LCTF), are illustrated. In addition, the principles of ISPs developed by adding polarized components to the dispersing-type imaging spectrometer, spatially modulated Fourier transform imaging spectrometer, and computer tomography imaging spectrometer are introduced. Moreover, the trends of ISP are discussed too. PMID:21942063

  2. Emerging Imaging Techniques

    PubMed Central

    McVeigh, Elliot R.

    2007-01-01

    This article reviews recent developments in selected imaging technologies focused on the cardiovascular system. The techniques covered are: ultrasound biomicroscopy (UBM), microSPECT, microPET, near infrared imaging, and quantum dots. For each technique, the basic physical principles are explained and recent example applications demonstrated. PMID:16614313

  3. Advanced Geosynchronous Imager

    NASA Technical Reports Server (NTRS)

    Chesters, Dennis

    1999-01-01

    For improved understanding of chaotic processes and the diurnal cycle, an advanced GOES imager must also have the multi-spectral spectral bands used by low earth orbit (LEO) imagers, with on-orbit calibration for all bands. A synergy between GEO and LEO radiometry would enable earth system scientists to fuse the remote sensing data from all the spaceborne platforms. These additional radiometric capabilities are designed to observe important physical processes that vary rapidly and unpredicably: smoke, fires, precipitation, ozone, volcanic ash, cloud phase and height, and surface temperature. We believe the technology now exists to develop an imaging system that can meet future weather reporting and earth system science needs. To meet this need, we propose a design for a comprehensive geosynchronous atmospheric imager. This imager is envisioned to fly on a GOES-N class spacecraft, within the volume, weight and power constraints of a platform similar to GOES-N while delivering 100 times more data and radiometric quality than the GOES-N imager. The higher data rate probably requires its own ground station, which could serve as a systems prototype for NOAA's next generation of operational satellites. For operational compatibility, our proposed advanced GOES imaging system contains the GOES-R requirements as a subset, and the GOES-N imager capabilities (and the sounder's imaging channels) as a further subset.

  4. Simultaneous multislice (SMS) imaging techniques

    PubMed Central

    Barth, Markus; Breuer, Felix; Koopmans, Peter J.; Poser, Benedikt A.

    2015-01-01

    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. Magn Reson Med 75:63–81, 2016. © 2015 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. PMID:26308571

  5. Simultaneous multislice (SMS) imaging techniques.

    PubMed

    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. PMID:26308571

  6. Advanced Coating Removal Techniques

    NASA Technical Reports Server (NTRS)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  7. Image compression technique

    DOEpatents

    Fu, Chi-Yung; Petrich, Loren I.

    1997-01-01

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.

  8. Image compression technique

    DOEpatents

    Fu, C.Y.; Petrich, L.I.

    1997-03-25

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.

  9. EDITORIAL: Imaging Systems and Techniques Imaging Systems and Techniques

    NASA Astrophysics Data System (ADS)

    Giakos, George; Yang, Wuqiang; Petrou, M.; Nikita, K. S.; Pastorino, M.; Amanatiadis, A.; Zentai, G.

    2011-10-01

    This special feature on Imaging Systems and Techniques comprises 27 technical papers, covering essential facets in imaging systems and techniques both in theory and applications, from research groups spanning three different continents. It mainly contains peer-reviewed articles from the IEEE International Conference on Imaging Systems and Techniques (IST 2011), held in Thessaloniki, Greece, as well a number of articles relevant to the scope of this issue. The multifaceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment, and the technological revolution; there is an urgent need to address and propose dynamic and innovative solutions to problems that tend to be either complex and static or rapidly evolving with a lot of unknowns. For instance, exploration of the engineering and physical principles of new imaging systems and techniques for medical applications, remote sensing, monitoring of space resources and enhanced awareness, exploration and management of natural resources, and environmental monitoring, are some of the areas that need to be addressed with urgency. Similarly, the development of efficient medical imaging techniques capable of providing physiological information at the molecular level is another important area of research. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, using high resolution and high selectivity nanoimaging techniques, can play an important role in the diagnosis and treatment of cancer, as well as provide efficient drug-delivery imaging solutions for disease treatment with increased sensitivity and specificity. On the other hand, technical advances in the development of efficient digital imaging systems and techniques and tomographic devices operating on electric impedance tomography, computed tomography, single-photon emission and positron emission tomography detection principles are anticipated to have a significant impact on a

  10. Improved structural characterization of the Earth's crust at the German Continental Deep Drilling Site using advanced seismic imaging techniques

    NASA Astrophysics Data System (ADS)

    Hloušek, F.; Hellwig, O.; Buske, S.

    2015-10-01

    This paper describes the principles of three novel seismic imaging techniques and their application to two deep seismic reflection data sets from the vicinity of the German Continental Deep Drilling Site (KTB). These imaging techniques are based on Kirchhoff prestack depth migration and use an inherent restriction of the migration operator to focus the wavefield to its actual reflection point. For Fresnel volume migration, the emergent angle at the receivers is estimated and then used to propagate the wavefield back into the subsurface along which the Fresnel volume is determined. The migration operator is restricted to this volume, thereby focusing the image to the part of the isochrone which physically contributes to the reflection. For coherency migration, the coherency of the wavefield at neighboring traces is calculated and used as a weighting factor within the migration integral, leading to a comparable focusing to the reflection point. For coherency-based Fresnel volume migration, both approaches are combined, resulting in an even more focused seismic image with significantly increased image quality. We applied these methods to two seismic data sets from the area around the KTB: a survey with standard split-spread geometry (KTB8502) and a sparse data set with a small number of source points in combination with short receiver lines (INSTRUCT93). The focusing approaches yield major improvements in the final images for both data sets. Incoherent noise and migration artifacts are reduced and the visibility of crustal structures is strongly enhanced, allowing for an improved geologic and tectonic characterization.

  11. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M.

    1993-12-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ``builds in`` the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ``process capability`` is illustrated and a comparison of 10-keV x-ray and Co{sup 60} gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe`s Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  12. Advanced qualification techniques

    NASA Astrophysics Data System (ADS)

    Winokur, P. S.; Shaneyfelt, M. R.; Meisenheimer, T. L.; Fleetwood, D. M.

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML 'builds in' the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish 'process capability' is illustrated and a comparison of 10-keV x-ray and Co-60 gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe's Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  13. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S.; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M. )

    1994-06-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ''builds in'' the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structure-to-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ''process capability'' is illustrated and a comparison of 10-kev x-ray wafer-level test system to support SPC and establish ''process capability'' is illustrated and a comparison of 10-keV x-ray and Co[sup 60] gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SCC Basic Specification No. 22900, Europe's Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  14. Advanced qualification techniques

    NASA Astrophysics Data System (ADS)

    Winokur, P. S.; Shaneyfelt, M. R.; Meisenheimer, T. L.; Fleetwood, D. M.

    1994-06-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML 'builds in' the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structure-to-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish 'process capability' is illustrated and a comparison of 10-keV x-ray and Co-60 gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SCC Basic Specification No. 22900, Europe's Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  15. Recent imaging advances in neurology.

    PubMed

    Rocchi, Lorenzo; Niccolini, Flavia; Politis, Marios

    2015-09-01

    Over the recent years, the application of neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) has considerably advanced the understanding of complex neurological disorders. PET is a powerful molecular imaging tool, which investigates the distribution and binding of radiochemicals attached to biologically relevant molecules; as such, this technique is able to give information on biochemistry and metabolism of the brain in health and disease. MRI uses high intensity magnetic fields and radiofrequency pulses to provide structural and functional information on tissues and organs in intact or diseased individuals, including the evaluation of white matter integrity, grey matter thickness and brain perfusion. The aim of this article is to review the most recent advances in neuroimaging research in common neurological disorders such as movement disorders, dementia, epilepsy, traumatic brain injury and multiple sclerosis, and to evaluate their contribution in the diagnosis and management of patients. PMID:25808503

  16. Renal imaging techniques.

    PubMed

    Hierholzer, K; Hierholzer, J

    1997-01-01

    The ancient approach to obtain an image of the kidneys (and other internal organs) was 'section-inspection-imaging' by drawing, painting, sculpturing, and modelling. The present study follows chronologically the development and use of sectioning techniques from ancient (often forbidden) methods to modern microdissection and maceration of silicone-rubber-injected tubules. Inspection evolved from the use of the naked eye to magnifying lenses, microscopes and finally electron microscopy. Pertinent examples such as the description of the kidneys as the site of urine formation, the visualization of loop structures in the renal medulla and the imaging of tight junction strands are discussed. Inspection or visualization of renal structure and function has been revolutionized by modern noninvasive techniques, such as X-ray imaging, imaging by radioisotopes, ultrasound, computer tomography and nuclear magnetic resonance. Pertinent examples are given demonstrating the potency of the various techniques. The contribution of computerized data evaluation is discussed. The development of micropuncture and microperfusion techniques has opened the field for direct imaging not only of renal (sub)structural details but also of functional parameters such as transtubular reabsorption rates, single glomerular capillary filtration and conductance of the paracellular pathway. We focus particularly on techniques specifically designed to visualize renal hemodynamic and transport parameters. PMID:9189257

  17. Advancing biomedical imaging

    PubMed Central

    Weissleder, Ralph; Nahrendorf, Matthias

    2015-01-01

    Imaging reveals complex structures and dynamic interactive processes, located deep inside the body, that are otherwise difficult to decipher. Numerous imaging modalities harness every last inch of the energy spectrum. Clinical modalities include magnetic resonance imaging (MRI), X-ray computed tomography (CT), ultrasound, and light-based methods [endoscopy and optical coherence tomography (OCT)]. Research modalities include various light microscopy techniques (confocal, multiphoton, total internal reflection, superresolution fluorescence microscopy), electron microscopy, mass spectrometry imaging, fluorescence tomography, bioluminescence, variations of OCT, and optoacoustic imaging, among a few others. Although clinical imaging and research microscopy are often isolated from one another, we argue that their combination and integration is not only informative but also essential to discovering new biology and interpreting clinical datasets in which signals invariably originate from hundreds to thousands of cells per voxel. PMID:26598657

  18. Advanced imaging system

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This document describes the Advanced Imaging System CCD based camera. The AIS1 camera system was developed at Photometric Ltd. in Tucson, Arizona as part of a Phase 2 SBIR contract No. NAS5-30171 from the NASA/Goddard Space Flight Center in Greenbelt, Maryland. The camera project was undertaken as a part of the Space Telescope Imaging Spectrograph (STIS) project. This document is intended to serve as a complete manual for the use and maintenance of the camera system. All the different parts of the camera hardware and software are discussed and complete schematics and source code listings are provided.

  19. Hepatocellular carcinoma: Advances in diagnostic imaging.

    PubMed

    Sun, Haoran; Song, Tianqiang

    2015-10-01

    Thanks to the growing knowledge on biological behaviors of hepatocellular carcinomas (HCC), as well as continuous improvement in imaging techniques and experienced interpretation of imaging features of the nodules in cirrhotic liver, the detection and characterization of HCC has improved in the past decade. A number of practice guidelines for imaging diagnosis have been developed to reduce interpretation variability and standardize management of HCC, and they are constantly updated with advances in imaging techniques and evidence based data from clinical series. In this article, we strive to review the imaging techniques and the characteristic features of hepatocellular carcinoma associated with cirrhotic liver, with emphasis on the diagnostic value of advanced magnetic resonance imaging (MRI) techniques and utilization of hepatocyte-specific MRI contrast agents. We also briefly describe the concept of liver imaging reporting and data systems and discuss the consensus and controversy of major practice guidelines. PMID:26632539

  20. [Progress in imaging techniques].

    PubMed

    Mishima, Kazuaki; Otsuka, Tsukasa

    2013-05-01

    Today it is common to perform real-time diagnosis and treatment via live broadcast as a method of education and to spread new technology for diagnosis and therapy in medical fields. Live medical broadcasts have developed along with broadcast technology. In the early days, live video feeds were sent from operating rooms to classrooms and lecture halls in universities and hospitals. However, the development of imaging techniques and communication networks enabled live broadcasts that bi-directionally link operating rooms and meeting halls during scientific meetings and live demonstration courses. Live broadcasts therefore became an important method for education and the dissemination of new medical technologies. The development of imaging techniques has contributed to more realistic live broadcasts through such innovative techniques as three-dimensional viewing and higher-definition 4K technology. In the future, live broadcasts will be transmitted on personal computers using regular Internet connections. In addition to the enhancement of image delivery technology, it will also be necessary to examine the entire image delivery environment carefully, including issues of security and privacy of personal information. PMID:23789334

  1. Recent advances in imaging technologies in dentistry

    PubMed Central

    Shah, Naseem; Bansal, Nikhil; Logani, Ajay

    2014-01-01

    Dentistry has witnessed tremendous advances in all its branches over the past three decades. With these advances, the need for more precise diagnostic tools, specially imaging methods, have become mandatory. From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging and ultrasound have also found place in modern dentistry. Changing from analogue to digital radiography has not only made the process simpler and faster but also made image storage, manipulation (brightness/contrast, image cropping, etc.) and retrieval easier. The three-dimensional imaging has made the complex cranio-facial structures more accessible for examination and early and accurate diagnosis of deep seated lesions. This paper is to review current advances in imaging technology and their uses in different disciplines of dentistry. PMID:25349663

  2. Development of advanced image analysis techniques for the in situ characterization of multiphase dispersions occurring in bioreactors.

    PubMed

    Galindo, Enrique; Larralde-Corona, C Patricia; Brito, Teresa; Córdova-Aguilar, Ma Soledad; Taboada, Blanca; Vega-Alvarado, Leticia; Corkidi, Gabriel

    2005-03-30

    Fermentation bioprocesses typically involve two liquid phases (i.e. water and organic compounds) and one gas phase (air), together with suspended solids (i.e. biomass), which are the components to be dispersed. Characterization of multiphase dispersions is required as it determines mass transfer efficiency and bioreactor homogeneity. It is also needed for the appropriate design of contacting equipment, helping in establishing optimum operational conditions. This work describes the development of image analysis based techniques with advantages (in terms of data acquisition and processing), for the characterization of oil drops and bubble diameters in complex simulated fermentation broths. The system consists of fully digital acquisition of in situ images obtained from the inside of a mixing tank using a CCD camera synchronized with a stroboscopic light source, which are processed with a versatile commercial software. To improve the automation of particle recognition and counting, the Hough transform (HT) was used, so bubbles and oil drops were automatically detected and the processing time was reduced by 55% without losing accuracy with respect to a fully manual analysis. The system has been used for the detailed characterization of a number of operational conditions, including oil content, biomass morphology, presence of surfactants (such as proteins) and viscosity of the aqueous phase. PMID:15707687

  3. Application of advanced seismic reflection imaging techniques to mapping permeable zones at Dixie Valley, Nevada. Final technical report

    SciTech Connect

    1998-02-18

    Multifold seismic reflection data from the Dixie Valley geothermal field in Nevada were reprocessed using a nonlinear optimization scheme called simulated annealing to model subsurface acoustic velocities, followed by a pre-stack Kirchhoff migration to produce accurate and detailed depth-migrated images of subsurface structure. In contrast to conventional processing techniques, these methods account for significant lateral variations in velocity and thus have the potential ability to image steeply-dipping faults and fractures that may affect permeability within geothermal fields. The optimization scheme develops two-dimensional velocity models to within 6% of velocities obtained from well and surface geologic data. Only the seismic data (i.e., first arrival times of P waves) are used to construct the velocity models and pre-stack migration images, and no other a priori assumptions are invoked. Velocities obtained by processing individual seismic tracks were integrated to develop a block diagram of velocities to 2.3 km depth within the Dixie Valley geothermal field. Details of the tectonic and stratigraphic structure allowed three dimensional extension of the interpretations of two dimensional data. Interpretations of the processed seismic data are compared with well data, surface mapping, and other geophysical data. The Dixie Valley fault along the southeastern Stillwater Range Piedmont is associated with a pronounced lateral velocity gradient that is interpreted to represent the juxtaposition of relatively low velocity basin-fill strata in the hanging wall against higher velocity crystalline rocks in the footwall. The down-dip geometry of the fault was evaluated by inverting arrival times from a negative move-out event, which we associate with the dipping fault plane, on individual shot gathers for seismic line SRC-3 for the location and depth of the associated reflection points on the fault.

  4. EDITORIAL: Imaging systems and techniques Imaging systems and techniques

    NASA Astrophysics Data System (ADS)

    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

  5. Spinal Cord Segmentation by One Dimensional Normalized Template Matching: A Novel, Quantitative Technique to Analyze Advanced Magnetic Resonance Imaging Data.

    PubMed

    Cadotte, Adam; Cadotte, David W; Livne, Micha; Cohen-Adad, Julien; Fleet, David; Mikulis, David; Fehlings, Michael G

    2015-01-01

    Spinal cord segmentation is a developing area of research intended to aid the processing and interpretation of advanced magnetic resonance imaging (MRI). For example, high resolution three-dimensional volumes can be segmented to provide a measurement of spinal cord atrophy. Spinal cord segmentation is difficult due to the variety of MRI contrasts and the variation in human anatomy. In this study we propose a new method of spinal cord segmentation based on one-dimensional template matching and provide several metrics that can be used to compare with other segmentation methods. A set of ground-truth data from 10 subjects was manually-segmented by two different raters. These ground truth data formed the basis of the segmentation algorithm. A user was required to manually initialize the spinal cord center-line on new images, taking less than one minute. Template matching was used to segment the new cord and a refined center line was calculated based on multiple centroids within the segmentation. Arc distances down the spinal cord and cross-sectional areas were calculated. Inter-rater validation was performed by comparing two manual raters (n = 10). Semi-automatic validation was performed by comparing the two manual raters to the semi-automatic method (n = 10). Comparing the semi-automatic method to one of the raters yielded a Dice coefficient of 0.91 +/- 0.02 for ten subjects, a mean distance between spinal cord center lines of 0.32 +/- 0.08 mm, and a Hausdorff distance of 1.82 +/- 0.33 mm. The absolute variation in cross-sectional area was comparable for the semi-automatic method versus manual segmentation when compared to inter-rater manual segmentation. The results demonstrate that this novel segmentation method performs as well as a manual rater for most segmentation metrics. It offers a new approach to study spinal cord disease and to quantitatively track changes within the spinal cord in an individual case and across cohorts of subjects. PMID:26445367

  6. Advanced endoscopic imaging to improve adenoma detection

    PubMed Central

    Neumann, Helmut; Nägel, Andreas; Buda, Andrea

    2015-01-01

    Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection rates. Those include high-definition imaging, dye-less chromoendoscopy techniques and novel, highly flexible endoscopes, some of them equipped with balloons or multiple lenses in order to improve adenoma detection rates. In this review we will focus on the newest developments in the field of colonoscopic imaging to improve adenoma detection rates. Described techniques include high-definition imaging, optical chromoendoscopy techniques, virtual chromoendoscopy techniques, the Third Eye Retroscope and other retroviewing devices, the G-EYE endoscope and the Full Spectrum Endoscopy-system. PMID:25789092

  7. Imaging of the pancreas: Recent advances

    PubMed Central

    Chaudhary, Vikas; Bano, Shahina

    2011-01-01

    A wide spectrum of anomalies of pancreas and the pancreatic duct system are commonly encountered at radiological evaluation. Diagnosing pancreatic lesions generally requires a multimodality approach. This review highlights the new advances in pancreatic imaging and their applications in the diagnosis and management of pancreatic pathologies. The mainstay techniques include computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), radionuclide imaging (RNI) and optical coherence tomography (OCT). PMID:21847450

  8. Advanced flow MRI: emerging techniques and applications.

    PubMed

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented. PMID:26944696

  9. Advanced MR Imaging of Gliomas: An Update

    PubMed Central

    Chiang, Shih-Wei; Chung, Hsiao-Wen; Tsai, Fong Y.; Chen, Cheng-Yu

    2013-01-01

    Recent advances in the treatment of cerebral gliomas have increased the demands on noninvasive neuroimaging for the diagnosis, therapeutic planning, tumor monitoring, and patient outcome prediction. In the meantime, improved magnetic resonance (MR) imaging techniques have shown much potentials in evaluating the key pathological features of the gliomas, including cellularity, invasiveness, mitotic activity, angiogenesis, and necrosis, hence, further shedding light on glioma grading before treatment. In this paper, an update of advanced MR imaging techniques is reviewed, and their potential roles as biomarkers of tumor grading are discussed. PMID:23862163

  10. Advanced electro-optical imaging techniques. [conference papers on sensor technology applicable to Large Space Telescope program

    NASA Technical Reports Server (NTRS)

    Sobieski, S. (Editor); Wampler, E. J. (Editor)

    1973-01-01

    The papers presented at the symposium are given which deal with the present state of sensors, as may be applicable to the Large Space Telescope (LST) program. Several aspects of sensors are covered including a discussion of the properties of photocathodes and the operational imaging camera tubes.

  11. Development of an interatmospheric window wavelength (5-9 μm) infrared thermography with an advanced image processing technique

    NASA Astrophysics Data System (ADS)

    Sato, Daisuke; Komiyama, Tatsuhito; Sakagami, Takahide; Kubo, Shiro

    2006-04-01

    Recently, deterioration of concrete structures before their design life has become a serious social problem in Japan. Nondestructive inspection techniques are required, for detecting defects and damages in concrete structures, such as subsurface void or delamination. As one of these techniques, the thermographic NDT can be applied as an effective NDT technique to inspect large area of the objective structure from distant place. In addition, it does not require any chemicals and application of physical excitation for inspection. However, the thermographic NDT has a shortcoming that the measurement results are affected by the reflection of atmospheric radiation due to the sunlight, sky or surrounding materials. Since most of the buildings in Japan are covered with luster materials with low emissivity, such as tile or mortal, infrared reflection on the surface is difficult to be neglected. To reduce the influence of these reflection noises, the infrared thermography with detectable wavelength from 5 to 8 μm, which coincides with absorption range of moisture, is utilized. In this research, a new infrared thermography with 5 to 8 μm wavelength range by applying a band pass filter and an uncooled microbolometer infrared array detector. Further, a new signal to noise (S/N) ratio improvement technique has been developed in order to compensate a deterioration of sensitivity due to the band pass filter.

  12. Advanced image memory architecture

    NASA Astrophysics Data System (ADS)

    Vercillo, Richard; McNeill, Kevin M.

    1994-05-01

    A workstation for radiographic images, known as the Arizona Viewing Console (AVC), was developed at the University of Arizona Health Sciences Center in the Department of Radiology. This workstation has been in use as a research tool to aid us in investigating how a radiologist interacts with a workstation, to determine which image processing features are required to aid the radiologist, to develop user interfaces and to support psychophysical and clinical studies. Results from these studies have show a need to increase the current image memory's available storage in order to accommodate high resolution images. The current triple-ported image memory can be allocated to store any number of images up to a combined total of 4 million pixels. Over the past couple of years, higher resolution images have become easier to generate with the advent of laser digitizers and computed radiology systems. As part of our research, a larger 32 million pixel image memory for AVC has been designed to replace the existing image memory.

  13. Advances in fluorescence labeling strategies for dynamic cellular imaging

    PubMed Central

    Dean, Kevin M; Palmer, Amy E

    2014-01-01

    Synergistic advances in optical physics, probe design, molecular biology, labeling techniques and computational analysis have propelled fluorescence imaging into new realms of spatiotemporal resolution and sensitivity. This review aims to discuss advances in fluorescent probes and live-cell labeling strategies, two areas that remain pivotal for future advances in imaging technology. Fluorescent protein– and bio-orthogonal–based methods for protein and RNA imaging are discussed as well as emerging bioengineering techniques that enable their expression at specific genomic loci (for example, CRISPR and TALENs). Important attributes that contribute to the success of each technique are emphasized, providing a guideline for future advances in dynamic live-cell imaging. PMID:24937069

  14. Advances in Procedural Techniques - Antegrade

    PubMed Central

    Wilson, William; Spratt, James C.

    2014-01-01

    There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the “hybrid’ approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited “interventional” collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

  15. Tooling Techniques Enhance Medical Imaging

    NASA Technical Reports Server (NTRS)

    2012-01-01

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

  16. Sensor image prediction techniques

    NASA Astrophysics Data System (ADS)

    Stenger, A. J.; Stone, W. R.; Berry, L.; Murray, T. J.

    1981-02-01

    The preparation of prediction imagery is a complex, costly, and time consuming process. Image prediction systems which produce a detailed replica of the image area require the extensive Defense Mapping Agency data base. The purpose of this study was to analyze the use of image predictions in order to determine whether a reduced set of more compact image features contains enough information to produce acceptable navigator performance. A job analysis of the navigator's mission tasks was performed. It showed that the cognitive and perceptual tasks he performs during navigation are identical to those performed for the targeting mission function. In addition, the results of the analysis of his performance when using a particular sensor can be extended to the analysis of this mission tasks using any sensor. An experimental approach was used to determine the relationship between navigator performance and the type of amount of information in the prediction image. A number of subjects were given image predictions containing varying levels of scene detail and different image features, and then asked to identify the predicted targets in corresponding dynamic flight sequences over scenes of cultural, terrain, and mixed (both cultural and terrain) content.

  17. SPECTRAL IMAGING TECHNIQUES FOR GRAIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three spectral imaging techniques were employed for the purpose of assessing the quality of cereal grains. Each of these techniques provided unique, yet complementary, information. Nuclear magnetic resonance (NMR), also called magnetic resonance imaging (MRI), was used to detect mobile components ...

  18. Advanced noninvasive imaging of spinal vascular malformations

    PubMed Central

    Eddleman, Christopher S.; Jeong, Hyun; Cashen, Ty A.; Walker, Matthew; Bendok, Bernard R.; Batjer, H. Hunt; Carroll, Timothy J.

    2010-01-01

    Spinal vascular malformations (SVMs) are an uncommon, heterogeneous group of vascular anomalies that can render devastating neurological consequences if they are not diagnosed and treated in a timely fashion. Imaging SVMs has always presented a formidable challenge because their clinical and imaging presentations resemble those of neoplasms, demyelination diseases, and infection. Advancements in noninvasive imaging modalities (MR and CT angiography) have increased during the last decade and have improved the ability to accurately diagnose spinal vascular anomalies. In addition, intraoperative imaging techniques have been developed that aid in the intraoperative assessment before, during, and after resection of these lesions with minimal and/or optimal use of spinal digital subtraction angiography. In this report, the authors review recent advancements in the imaging of SVMs that will likely lead to more timely diagnoses and treatment while reducing procedural risk exposure to the patients who harbor these uncommon spinal lesions. PMID:19119895

  19. Review: Magnetic resonance imaging techniques in ophthalmology

    PubMed Central

    Fagan, Andrew J.

    2012-01-01

    Imaging the eye with magnetic resonance imaging (MRI) has proved difficult due to the eye’s propensity to move involuntarily over typical imaging timescales, obscuring the fine structure in the eye due to the resulting motion artifacts. However, advances in MRI technology help to mitigate such drawbacks, enabling the acquisition of high spatiotemporal resolution images with a variety of contrast mechanisms. This review aims to classify the MRI techniques used to date in clinical and preclinical ophthalmologic studies, describing the qualitative and quantitative information that may be extracted and how this may inform on ocular pathophysiology. PMID:23112569

  20. Advances of imaging for hepatocellular carcinoma.

    PubMed

    Choi, Byung Ihn

    2010-07-01

    A variety of imaging modalities, including ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, and angiography, are currently used in evaluating patients with chronic liver disease and suspected hepatocellular carcinoma (HCC). Further technological advancement will undoubtedly have a major impact on liver tumor imaging. Increased speed of data acquisition and consequently shorter scan times in CT and MRI show further improvement in resolution by further reducing motion artifacts. Development of new contrast materials for liver tumor imaging in US and MRI improve tumor detection and characterization by increasing the contrast resolution. Currently available advanced US techniques in the evaluation of HCC are various harmonic imaging techniques with contrast agents, volume imaging, and recently, US elastography, that has been developing and might play a role in characterizing liver nodules in the future. The latest advance in CT is the multidetector (MD) CT scanner where a 256- or 320-detector CT was introduced. Recent studies describe the high sensitivity of double arterial phase imaging in hepatic tumor detection and the usefulness of CT angiography by using MD CT in a detailed assessment of hepatic arterial anatomy using a three-dimensional dataset. In addition, perfusion CT imaging is also being developed and can be used for the characterization and treatment monitoring of HCC. Dual-energy CT with new technology is also continuously progressing. Advances in MR technology, including hardware and pulse sequence implementation, allow acquisition times to be reduced to the time frame of one breathhold, providing multiphasic dynamic MRI. Functional MRI including diffusion-weighted MRI, MR elastography, and new MR contrast agent with dual function have been investigated for the clinical utility of detection and characterization of HCCs. Functional MRI has a potential to be a promising technique for assessing HCC. PMID:20616584

  1. Development of an Advanced Technique for Mapping and Monitoring Sea and Lake Ice in Preparation for GOES-R Advanced Baseline Imager (ABI)

    NASA Astrophysics Data System (ADS)

    Nazari, R.; Temimi, M.; Khanbilvardi, R.; Romanov, P.

    2008-05-01

    In recent years, the uniqueness of the Earth's ice covered regions and their importance to the world is being increasingly recognized. They are considered vital and valuable for a variety of economic, environmental, and social reasons. Ice information can also improve weather and climate predictions. Observations show that Arctic ice is decreasing in both thickness and extent which will lead to the change in absorption of solar radiation and temperature of the earth. The increasing activity in ice-affected waters has led to a growing requirement for ice information and better mapping systems with improvements in both time and spatial resolution. A variety of Earth Observation sensors are used to map ice covered areas. Visible-Infrared sensors at moderate-resolution from polar orbiting satellites (NOAA-AVHRR, MODIS Aqua/ Terra) have been used extensively because of their easy accessibility. However, clouds, fog and low time resolutions limit the use of this type of sensor to fully meet operational ice mapping requirements, particularly in cloud- and fog ice zones. The primary objective of this research is to explore the potentials of mapping ice with the geostationary satellites which can provide a reasonably good time resolution and satisfactory spatial resolutions. The aim of this ongoing project is to develop an automated ice-mapping algorithm, which would make maximum use of GOES-R ABI's improved observing capabilities and to be the pioneer of creating daily ice maps from a geostationary satellite. Data collected by SEVIRI instrument onboard of Meteosat Second Generation (MSG) satellite have been used as a prototype. The Northern region of the Caspian Sea has been selected for algorithm development and calibration. The approach used in the algorithm development includes daily cloud-clear image compositing as well as pixel-by-pixel image classification using spectral criteria. All available spectral channels (reflectance and temperature) have been tested and used

  2. Advanced Land Imager Assessment System

    NASA Technical Reports Server (NTRS)

    Chander, Gyanesh; Choate, Mike; Christopherson, Jon; Hollaren, Doug; Morfitt, Ron; Nelson, Jim; Nelson, Shar; Storey, James; Helder, Dennis; Ruggles, Tim; Kaita, Ed; Levy, Raviv; Ong, Lawrence; Markham, Brian; Schweiss, Robert

    2008-01-01

    The Advanced Land Imager Assessment System (ALIAS) supports radiometric and geometric image processing for the Advanced Land Imager (ALI) instrument onboard NASA s Earth Observing-1 (EO-1) satellite. ALIAS consists of two processing subsystems for radiometric and geometric processing of the ALI s multispectral imagery. The radiometric processing subsystem characterizes and corrects, where possible, radiometric qualities including: coherent, impulse; and random noise; signal-to-noise ratios (SNRs); detector operability; gain; bias; saturation levels; striping and banding; and the stability of detector performance. The geometric processing subsystem and analysis capabilities support sensor alignment calibrations, sensor chip assembly (SCA)-to-SCA alignments and band-to-band alignment; and perform geodetic accuracy assessments, modulation transfer function (MTF) characterizations, and image-to-image characterizations. ALIAS also characterizes and corrects band-toband registration, and performs systematic precision and terrain correction of ALI images. This system can geometrically correct, and automatically mosaic, the SCA image strips into a seamless, map-projected image. This system provides a large database, which enables bulk trending for all ALI image data and significant instrument telemetry. Bulk trending consists of two functions: Housekeeping Processing and Bulk Radiometric Processing. The Housekeeping function pulls telemetry and temperature information from the instrument housekeeping files and writes this information to a database for trending. The Bulk Radiometric Processing function writes statistical information from the dark data acquired before and after the Earth imagery and the lamp data to the database for trending. This allows for multi-scene statistical analyses.

  3. Interpretation techniques. [image enhancement and pattern recognition

    NASA Technical Reports Server (NTRS)

    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.

  4. Automated medical image segmentation techniques

    PubMed Central

    Sharma, Neeraj; Aggarwal, Lalit M.

    2010-01-01

    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. PMID:20177565

  5. [Advances in musculoskeletal MR imaging].

    PubMed

    Ho, Michael; Andreisek, Gustav

    2015-09-01

    Musculoskeletal imaging is a rapidly developing field offering several new techniques. MR neurography provides an additive value with complementary and precise information about peripheral nerves. Hereby, MR neurography not only enables the radiologist to differentiate between a mononeuropathic or a polyneuropathic process, but also helps to find nerve compression syndromes by visualizing the nerve surrounding structures as well. An additional administration of contrast agent enables detection of tumors and inflammation of peripheral nerves. Whole body MRI opens new possibilities for detection and follow-up in oncological disorders, systemic diseases, in pediatric diagnostics and in preventive medicine. Guidelines are useful for an evidence-based application of this technique. MRI is generally considered to be the gold standard in diagnostic imaging of the spine. Continuous technical developments have led to a better image quality. New guidelines for standardized image interpretation and reporting have been published and should be used to avoid loss of information from high resolution imaging to effective treatment. PMID:26331202

  6. Advanced Spectroscopy Technique for Biomedicine

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhua; Zeng, Haishan

    This chapter presents an overview of the applications of optical spectroscopy in biomedicine. We focus on the optical design aspects of advanced biomedical spectroscopy systems, Raman spectroscopy system in particular. Detailed components and system integration are provided. As examples, two real-time in vivo Raman spectroscopy systems, one for skin cancer detection and the other for endoscopic lung cancer detection, and an in vivo confocal Raman spectroscopy system for skin assessment are presented. The applications of Raman spectroscopy in cancer diagnosis of the skin, lung, colon, oral cavity, gastrointestinal tract, breast, and cervix are summarized.

  7. Stitching Techniques Advance Optics Manufacturing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an R&D 100 award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography."

  8. Recent advances in the imaging of hepatocellular carcinoma

    PubMed Central

    You, Myung-Won; Kim, Kyoung Won; Lee, So Jung; Shin, Yong Moon; Kim, Jin Hee; Lee, Moon-Gyu

    2015-01-01

    The role of imaging is crucial for the surveillance, diagnosis, staging and treatment monitoring of hepatocellular carcinoma (HCC). Over the past few years, considerable technical advances were made in imaging of HCCs. New imaging technology, however, has introduced new challenges in our clinical practice. In this article, the current status of clinical imaging techniques for HCC is addressed. The diagnostic performance of imaging techniques in the context of recent clinical guidelines is also presented. PMID:25834808

  9. Urologic imaging and interventional techniques

    SciTech Connect

    Bush, W.H.

    1989-01-01

    This book provides an overview of all imaging modalities and invasive techniques of the genitourinary system. Three general chapters discuss ionic and nonionic contrast media, the management of reactions to contrast media, and radiation doses from various uroradiologic procedures. Chapters are devoted to intravenous pyelography, computed tomography, magnetic resonance imaging, ultrasound, nuclear medicine, lymphography, arteriography, and venography. Two chapters discuss the pediatric applications of uroradiology and ultrasound. Two chapters integrate the various imaging techniques of the upper and lower genitourinary systems into an algorithmic approach for various pathologic entities.

  10. Advanced measurement techniques, part 1

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.; Carraway, Debra L.; Manuel, Gregory S.; Croom, Cynthia C.

    1987-01-01

    In modern laminar flow flight and wind tunnel research, it is important to understand the specific cause(s) of laminar to turbulent boundary layer transition. Such information is crucial to the exploration of the limits of practical application of laminar flow for drag reduction on aircraft. The process of transition involves both the possible modes of disturbance growth, and the environmental conditioning of the instabilities by freestream or surface conditions. The possible modes of disturbance growth include viscous, inviscid, and modes which may bypass these natural ones. Theory provides information on the possible modes of disturbance amplification, but experimentation must be relied upon to determine which of those modes actually dominates the transition process in a given environment. The results to date of research on advanced devices and methods used for the study of transition phenomena in the subsonic and transonic flight and wind tunnel environments are presented.

  11. Foundations of Advanced Magnetic Resonance Imaging

    PubMed Central

    Bammer, Roland; Skare, Stefan; Newbould, Rexford; Liu, Chunlei; Thijs, Vincent; Ropele, Stefan; Clayton, David B.; Krueger, Gunnar; Moseley, Michael E.; Glover, Gary H.

    2005-01-01

    Summary: During the past decade, major breakthroughs in magnetic resonance imaging (MRI) quality were made by means of quantum leaps in scanner hardware and pulse sequences. Some advanced MRI techniques have truly revolutionized the detection of disease states and MRI can now—within a few minutes—acquire important quantitative information noninvasively from an individual in any plane or volume at comparatively high resolution. This article provides an overview of the most common advanced MRI methods including diffusion MRI, perfusion MRI, functional MRI, and the strengths and weaknesses of MRI at high magnetic field strengths. PMID:15897944

  12. Advances in multimodality molecular imaging

    PubMed Central

    Zaidi, Habib; Prasad, Rameshwar

    2009-01-01

    Multimodality molecular imaging using high resolution positron emission tomography (PET) combined with other modalities is now playing a pivotal role in basic and clinical research. The introduction of combined PET/CT systems in clinical setting has revolutionized the practice of diagnostic imaging. The complementarity between the intrinsically aligned anatomic (CT) and functional or metabolic (PET) information provided in a “one-stop shop” and the possibility to use CT images for attenuation correction of the PET data has been the driving force behind the success of this technology. On the other hand, combining PET with Magnetic Resonance Imaging (MRI) in a single gantry is technically more challenging owing to the strong magnetic fields. Nevertheless, significant progress has been made resulting in the design of few preclinical PET systems and one human prototype dedicated for simultaneous PET/MR brain imaging. This paper discusses recent advances in PET instrumentation and the advantages and challenges of multimodality imaging systems. Future opportunities and the challenges facing the adoption of multimodality imaging instrumentation will also be addressed. PMID:20098557

  13. Application of conventional and advanced techniques for the interpretation of LANDSAT 2 images for the study of linears in the Friuli earthquake area

    NASA Technical Reports Server (NTRS)

    Cardamone, P.; Lechi, G. M.; Cavallin, A.; Marino, C. M.; Zanferrari, A.

    1977-01-01

    The results obtained in the study of linears derived from the analysis of LANDSAT 2 images recorded over Friuli during 1975 are described. Particular attention is devoted to the comparison of several passes in different bands, scales and photographic supports. Moreover reference is made to aerial photographic interpretation in selected sites and to the information obtained by laser techniques.

  14. Nuclear material investigations by advanced analytical techniques

    NASA Astrophysics Data System (ADS)

    Degueldre, C.; Kuri, G.; Martin, M.; Froideval, A.; Cammelli, S.; Orlov, A.; Bertsch, J.; Pouchon, M. A.

    2010-10-01

    Advanced analytical techniques have been used to characterize nuclear materials at the Paul Scherrer Institute during the last decade. The analysed materials ranged from reactor pressure vessel (RPV) steels, Zircaloy claddings to fuel samples. The processes studied included copper cluster build up in RPV steels, corrosion, mechanical and irradiation damage behaviour of PWR and BWR cladding materials as well as fuel defect development. The used advanced techniques included muon spin resonance spectroscopy for zirconium alloy defect characterization while fuel element materials were analysed by techniques derived from neutron and X-ray scattering and absorption spectroscopy.

  15. Imaging techniques in childhood arthritis.

    PubMed

    Harcke, H T; Mandell, G A; Cassell, I L

    1997-08-01

    Technological advances in imaging have given physicians caring for children with arthritis a greater opportunity to detect abnormalities early in the course of a disease and better methods for monitoring chronic changes. Indications for using radiography, bone densitometry, nuclear medicine, ultrasound, CT scanning, and MR imaging are discussed in this article. In this era of managed care, the practicing clinician is urged more than ever to consult with the radiologist in selecting the study or sequence of studies to be used in particular case. In this way, evaluation can be limited to the most effective strategy from both the clinical and cost perspectives. PMID:9287376

  16. Imaging Instrumentation and Techniques for Precision Radiotherapy

    NASA Astrophysics Data System (ADS)

    Parodi, Katia; Parodi, Katia; Thieke, Christian; Thieke, Christian

    Over the last decade, several technological advances have considerably improved the achievable precision of dose delivery in radiation therapy. Clinical exploitation of the superior tumor-dose conformality offered by modern radiotherapy techniques like intensity-modulated radiotherapy and ion beam therapy requires morphological and functional assessment of the tumor during the entire therapy chain from treatment planning to beam application and treatment response evaluation. This chapter will address the main rationale and role of imaging in state-of-the-art external beam radiotherapy. Moreover, it will present the status of novel imaging instrumentation and techniques being nowadays introduced in clinical use or still under development for image guidance and, ultimately, dose guidance of precision radiotherapy.

  17. Imaging Tumor Hypoxia to Advance Radiation Oncology

    PubMed Central

    Lee, Chen-Ting; Boss, Mary-Keara

    2014-01-01

    Abstract Significance: Most solid tumors contain regions of low oxygenation or hypoxia. Tumor hypoxia has been associated with a poor clinical outcome and plays a critical role in tumor radioresistance. Recent Advances: Two main types of hypoxia exist in the tumor microenvironment: chronic and cycling hypoxia. Chronic hypoxia results from the limited diffusion distance of oxygen, and cycling hypoxia primarily results from the variation in microvessel red blood cell flux and temporary disturbances in perfusion. Chronic hypoxia may cause either tumor progression or regressive effects depending on the tumor model. However, there is a general trend toward the development of a more aggressive phenotype after cycling hypoxia. With advanced hypoxia imaging techniques, spatiotemporal characteristics of tumor hypoxia and the changes to the tumor microenvironment can be analyzed. Critical Issues: In this review, we focus on the biological and clinical consequences of chronic and cycling hypoxia on radiation treatment. We also discuss the advanced non-invasive imaging techniques that have been developed to detect and monitor tumor hypoxia in preclinical and clinical studies. Future Directions: A better understanding of the mechanisms of tumor hypoxia with non-invasive imaging will provide a basis for improved radiation therapeutic practices. Antioxid. Redox Signal. 21, 313–337. PMID:24329000

  18. Diagnostic cardiology: Noninvasive imaging techniques

    SciTech Connect

    Come, P.C.

    1985-01-01

    This book contains 23 chapters. Some of the chapter titles are: The chest x-ray and cardiac series; Computed tomographic scanning of the heart, coronary arteries, and great vessels; Digital subtraction angiography in the assessment of cardiovascular disease; Magnetic resonance: technique and cardiac applications; Basics of radiation physics and instrumentation; and Nuclear imaging: the assessment of cardiac performance.

  19. Fast Hadamard Spectroscopic Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Goelman, G.

    1994-07-01

    Fast Hadamard spectroscopic imaging (HSI) techniques are presented. These techniques combine transverse and longitudinal encoding to obtain multiple-volume localization. The fast techniques are optimized for nuclei with short T2 and long T1 relaxation times and are therefore suitable for in vivo31P spectroscopy. When volume coils are used in fast HSI techniques, the signal-to-noise ratio per unit time (SNRT) is equal to the SNRT in regular HSI techniques. When surface coils are used, fast HSI techniques give significant improvement of SNRT over conventional HSI. Several fast techniques which are different in total experimental time and pulse demands are presented. When the number of acquisitions in a single repetition time is not higher than two, fast HSI techniques can be used with surface coils and the B1 inhomogeneity does not affect the localization. Surface-coil experiments on phantoms and on human calf muscles in vivo are presented. In addition, it is shown that the localization obtained by the HSI techniques are independent of the repetition times.

  20. Recent advances in imaging subcellular processes

    PubMed Central

    Myers, Kenneth A.; Janetopoulos, Christopher

    2016-01-01

    Cell biology came about with the ability to first visualize cells. As microscopy techniques advanced, the early microscopists became the first cell biologists to observe the inner workings and subcellular structures that control life. This ability to see organelles within a cell provided scientists with the first understanding of how cells function. The visualization of the dynamic architecture of subcellular structures now often drives questions as researchers seek to understand the intricacies of the cell. With the advent of fluorescent labeling techniques, better and new optical techniques, and more sensitive and faster cameras, a whole array of questions can now be asked. There has been an explosion of new light microscopic techniques, and the race is on to build better and more powerful imaging systems so that we can further our understanding of the spatial and temporal mechanisms controlling molecular cell biology. PMID:27408708

  1. Recent advances in imaging subcellular processes.

    PubMed

    Myers, Kenneth A; Janetopoulos, Christopher

    2016-01-01

    Cell biology came about with the ability to first visualize cells. As microscopy techniques advanced, the early microscopists became the first cell biologists to observe the inner workings and subcellular structures that control life. This ability to see organelles within a cell provided scientists with the first understanding of how cells function. The visualization of the dynamic architecture of subcellular structures now often drives questions as researchers seek to understand the intricacies of the cell. With the advent of fluorescent labeling techniques, better and new optical techniques, and more sensitive and faster cameras, a whole array of questions can now be asked. There has been an explosion of new light microscopic techniques, and the race is on to build better and more powerful imaging systems so that we can further our understanding of the spatial and temporal mechanisms controlling molecular cell biology. PMID:27408708

  2. Advanced imaging in COPD: insights into pulmonary pathophysiology

    PubMed Central

    Milne, Stephen

    2014-01-01

    Chronic obstructive pulmonary disease (COPD) involves a complex interaction of structural and functional abnormalities. The two have long been studied in isolation. However, advanced imaging techniques allow us to simultaneously assess pathological processes and their physiological consequences. This review gives a comprehensive account of the various advanced imaging modalities used to study COPD, including computed tomography (CT), magnetic resonance imaging (MRI), and the nuclear medicine techniques positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Some more recent developments in imaging technology, including micro-CT, synchrotron imaging, optical coherence tomography (OCT) and electrical impedance tomography (EIT), are also described. The authors identify the pathophysiological insights gained from these techniques, and speculate on the future role of advanced imaging in both clinical and research settings. PMID:25478198

  3. Retinal Imaging Techniques for Diabetic Retinopathy Screening.

    PubMed

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

    2016-03-01

    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

  4. Hybrid mesh generation using advancing reduction technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study presents an extension of the application of the advancing reduction technique to the hybrid mesh generation. The proposed algorithm is based on a pre-generated rectangle mesh (RM) with a certain orientation. The intersection points between the two sets of perpendicular mesh lines in RM an...

  5. Noncontrast MR techniques and imaging of cartilage.

    PubMed

    Koff, Mathew F; Potter, Hollis G

    2009-05-01

    Recent advances in noncontrast MR imaging produce images with higher quality for standardized diagnostic interpretation and in many cases may obviate the need for intra-articular contrast agents. These techniques may now be applied to all joints, and are particularly efficacious in the assessment of articular cartilage. Additional specialized noncontrast sequences enable the direct quantitative assessment of articular cartilage and other joint structures, thereby providing indirect assessment of tissue health and biochemistry. T2 mapping displays local water content and collagen fibril orientation, and the method of T1 rho mapping displays the local proteoglycan content of the tissue. Ultrashort echo imaging improves the contrast of joint structures with high tissue isotropy or low water content, such as ligament, tendon, and meniscus. PMID:19361672

  6. Imaging Body Fat: Techniques and Cardiometabolic Implications

    PubMed Central

    Wang, H.; Chen, Y. E; Eitzman, D.T.

    2014-01-01

    Obesity is a world-wide epidemic and is associated with multiple comorbidities. The mechanisms underlying the relationship between obesity and adverse health outcomes remain poorly understood. This may be due to several factors including the crude measures used to estimate adiposity, the striking heterogeneity between adipose tissue depots, and the influence of fat accumulation in multiple organs. In order to advance our understanding of fat stores and associated co-morbidities in humans, it will be necessary to image adiposity throughout the body and ultimately also assess its functionality. Large clinical studies are demonstrating the prognostic importance of adipose tissue imaging. Newer techniques capable of imaging fat metabolism and other functions of adipose tissue may provide additional prognostic utility and may be useful in guiding therapeutic interventions. PMID:25147343

  7. High-Resolution and Animal Imaging Instrumentation and Techniques

    NASA Astrophysics Data System (ADS)

    Belcari, Nicola; Guerra, AlbertoDel

    During the last decade we have observed a growing interest in "in vivo" imaging techniques for small animals. This is due to the necessity of studying biochemical processes at a molecular level for pharmacology, genetic, and pathology investigations. This field of research is usually called "molecular imaging."Advances in biological understanding have been accompanied by technological advances in instrumentation and techniques and image-reconstruction software, resulting in improved image quality, visibility, and interpretation. The main technological challenge is then the design of systems with high spatial resolution and high sensitivity.

  8. Advances in cardiac magnetic resonance imaging of congenital heart disease.

    PubMed

    Driessen, Mieke M P; Breur, Johannes M P J; Budde, Ricardo P J; van Oorschot, Joep W M; van Kimmenade, Roland R J; Sieswerda, Gertjan Tj; Meijboom, Folkert J; Leiner, Tim

    2015-01-01

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological advances have enabled faster and more robust cardiovascular magnetic resonance with improved image quality and spatial as well as temporal resolution. This review aims to provide an overview of advances in cardiovascular magnetic resonance hardware and acquisition techniques relevant to both pediatric and adult patients with congenital heart disease and discusses the techniques used to assess function, anatomy, flow and tissue characterization. PMID:25552386

  9. Recent advancement of turbulent flow measurement techniques

    NASA Technical Reports Server (NTRS)

    Battle, T.; Wang, P.; Cheng, D. Y.

    1974-01-01

    Advancements of the fluctuating density gradient cross beam laser Schlieren technique, the fluctuating line-reversal temperature measurement and the development of the two-dimensional drag-sensing probe to a three-dimensional drag-sensing probe are discussed. The three-dimensionality of the instantaneous momentum vector can shed some light on the nature of turbulence especially with swirling flow. All three measured fluctuating quantities (density, temperature, and momentum) can provide valuable information for theoreticians.

  10. NMR Imaging: Instrumentation and Techniques

    NASA Astrophysics Data System (ADS)

    Tingle, Jeremy Mark

    Available from UMI in association with The British Library. This thesis presents three original contributions to the field of Nuclear Magnetic Resonance (NMR): the experimental framework and analysis for the measurement of a new imaging parameter to describe perfusion; the measurement and analysis of magnetic field inhomogeneity and a practical correction system for their reduction; a novel system for the synchronous control of NMR experiments based on the microprogrammed concept. The thesis begins with an introduction to the theory of NMR. The application of NMR to imaging is also introduced with emphasis on the techniques which developed into those in common use today. Inaccurate determination of the traditional NMR parameters (T_1 and T_2 and the molecular diffusion coefficient) can be caused by non-diffusive fluid movement within the sample. The experimental basis for determining a new imaging parameter --the Perfusion coefficient--is presented. This provides a measure of forced isotropic fluid motion through an organ or tissue. The instrumentation required for conducting NMR experiments is described in order to introduce the contribution made in this area during this research: A sequence controller. The controller is based on the concept of microprogramming and enables completely synchronous output of 128 bits of data. The software for the generation and storage of control data and the regulation of the data to provide experimental control is microcomputer based. It affords precise and accurate regulation of the magnetic field gradients, the rf synthesizer and the spectrometer for spectroscopic and imaging applications. Fundamental to the science of NMR is the presence of a magnetic field. A detailed study of the analysis of magnetic field inhomogeneity in terms of spherical harmonics is presented. The field of a whole body imaging system with poor inhomogeneity was measured and analyzed to determine and describe the components of the inhomogeneity. Finally a

  11. Advanced Image Search: A Strategy for Creating Presentation Boards

    ERIC Educational Resources Information Center

    Frey, Diane K.; Hines, Jean D.; Swinker, Mary E.

    2008-01-01

    Finding relevant digital images to create presentation boards requires advanced search skills. This article describes a course assignment involving a technique designed to develop students' literacy skills with respect to locating images of desired quality and content from Internet databases. The assignment was applied in a collegiate apparel…

  12. Contemporary retinal imaging techniques in diabetic retinopathy: a review.

    PubMed

    Cole, Emily Dawn; Novais, Eduardo Amorim; Louzada, Ricardo Noguera; Waheed, Nadia K

    2016-05-01

    Over the last decade, there has been an expansion of imaging modalities available to clinicians to diagnose and monitor the treatment and progression of diabetic retinopathy. Recently, advances in image technologies related to OCT and OCT angiography have enabled improved visualization and understanding of this disease. In this review, we will describe the use of imaging techniques such as colour fundus photography, fundus autofluorescence, fluorescein angiography, infrared reflectance imaging, OCT, OCT-Angiography and techniques in adaptive optics and hyperspectral imaging in the diagnosis and management of diabetic retinopathy. PMID:26841250

  13. Imaging techniques in biology and medicine

    SciTech Connect

    Swenberg, C.E.

    1988-01-01

    This book serves as an introduction to some aspects of imaging techniques as utilized in biology and medicine. Techniques presented include image processing, ultrasound, radiotracers, autoradiography, computed tomography, and MRI (all major imaging techniques). The underlying mathematics and physics are kept to a minimum.

  14. Recent advances in human viruses imaging studies.

    PubMed

    Florian, Paula Ecaterina; Rouillé, Yves; Ruta, Simona; Nichita, Norica; Roseanu, Anca

    2016-06-01

    Microscopy techniques are often exploited by virologists to investigate molecular details of critical steps in viruses' life cycles such as host cell recognition and entry, genome replication, intracellular trafficking, and release of mature virions. Fluorescence microscopy is the most attractive tool employed to detect intracellular localizations of various stages of the viral infection and monitor the pathogen-host interactions associated with them. Super-resolution microscopy techniques have overcome the technical limitations of conventional microscopy and offered new exciting insights into the formation and trafficking of human viruses. In addition, the development of state-of-the art electron microscopy techniques has become particularly important in studying virus morphogenesis by revealing ground-braking ultrastructural details of this process. This review provides recent advances in human viruses imaging in both, in vitro cell culture systems and in vivo, in the animal models recently developed. The newly available imaging technologies bring a major contribution to our understanding of virus pathogenesis and will become an important tool in early diagnosis of viral infection and the development of novel therapeutics to combat the disease. PMID:27059598

  15. Advanced Tools and Techniques for Formal Techniques in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Knight, John C.

    2005-01-01

    This is the final technical report for grant number NAG-1-02101. The title of this grant was "Advanced Tools and Techniques for Formal Techniques In Aerospace Systems". The principal investigator on this grant was Dr. John C. Knight of the Computer Science Department, University of Virginia, Charlottesville, Virginia 22904-4740. This report summarizes activities under the grant during the period 7/01/2002 to 9/30/2004. This report is organized as follows. In section 2, the technical background of the grant is summarized. Section 3 lists accomplishments and section 4 lists students funded under the grant. In section 5, we present a list of presentations given at various academic and research institutions about the research conducted. Finally, a list of publications generated under this grant is included in section 6.

  16. Bone fragility and imaging techniques

    PubMed Central

    D’Elia, Giovanni; Caracchini, Giuseppe; Cavalli, Loredana; Innocenti, Paolo

    2009-01-01

    Bone fragility is a silent condition that increases bone fracture risk, enhanced by low bone mass and microarchitecture deterioration of bone tissue that lead to osteoporosis. Fragility fractures are the major clinical manifestation of osteoporosis. A large body of epidemiological data indicates that the current standard for predicting fragility fracture risk is an areal BMD (aBMD) measurement by DXA. Although mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Thus, bone strength is explained not only by BMD but also by macrostructural and microstructural characteristics of bone tissue. Imaging diagnostics, through the use of X-rays, DXA, Ultrasonography, CT and MR, provides methods for diagnosis and characterization of fractures, and semi- and quantitative methods for assessment of bone consistency and strength, that become precious for bone fragility clinical management if they are integrated by clinical risk factors. The last employment of sophisticated non-invasively imaging techniques in clinical research as high-resolution CT (hrCT), microCT (μ-CT), high-resolution MR (hrMR) and, microRM (μRM), combined with finite element analysis methods, open to new challenges in a better bone strength assessment to enhance the comprehension of biomechanical parameters and the prediction of fragility fractures. PMID:22461252

  17. Advances in Optical Spectroscopy and Imaging of Breast Lesions

    SciTech Connect

    Demos, S; Vogel, A J; Gandjbakhche, A H

    2006-01-03

    A review is presented of recent advances in optical imaging and spectroscopy and the use of light for addressing breast cancer issues. Spectroscopic techniques offer the means to characterize tissue components and obtain functional information in real time. Three-dimensional optical imaging of the breast using various illumination and signal collection schemes in combination with image reconstruction algorithms may provide a new tool for cancer detection and monitoring of treatment.

  18. Advanced image analysis for the preservation of cultural heritage

    NASA Astrophysics Data System (ADS)

    France, Fenella G.; Christens-Barry, William; Toth, Michael B.; Boydston, Kenneth

    2010-02-01

    The Library of Congress' Preservation Research and Testing Division has established an advanced preservation studies scientific program for research and analysis of the diverse range of cultural heritage objects in its collection. Using this system, the Library is currently developing specialized integrated research methodologies for extending preservation analytical capacities through non-destructive hyperspectral imaging of cultural objects. The research program has revealed key information to support preservation specialists, scholars and other institutions. The approach requires close and ongoing collaboration between a range of scientific and cultural heritage personnel - imaging and preservation scientists, art historians, curators, conservators and technology analysts. A research project of the Pierre L'Enfant Plan of Washington DC, 1791 had been undertaken to implement and advance the image analysis capabilities of the imaging system. Innovative imaging options and analysis techniques allow greater processing and analysis capacities to establish the imaging technique as the first initial non-invasive analysis and documentation step in all cultural heritage analyses. Mapping spectral responses, organic and inorganic data, topography semi-microscopic imaging, and creating full spectrum images have greatly extended this capacity from a simple image capture technique. Linking hyperspectral data with other non-destructive analyses has further enhanced the research potential of this image analysis technique.

  19. Advanced Bode Plot Techniques for Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.

    The Bode plot, displayed as either impedance or admittance versus frequency, is the most basic test used by ultrasonic transducer designers. With simplicity and ease-of-use, Bode plots are ideal for baseline comparisons such as spacing of parasitic modes or impedance, but quite often the subtleties that manifest as poor process control are hard to interpret or are nonexistence. In-process testing of transducers is time consuming for quantifying statistical aberrations, and assessments made indirectly via the workpiece are difficult. This research investigates the use of advanced Bode plot techniques to compare ultrasonic transducers with known "good" and known "bad" process performance, with the goal of a-priori process assessment. These advanced techniques expand from the basic constant voltage versus frequency sweep to include constant current and constant velocity interrogated locally on transducer or tool; they also include up and down directional frequency sweeps to quantify hysteresis effects like jumping and dropping phenomena. The investigation focuses solely on the common PZT8 piezoelectric material used with welding transducers for semiconductor wire bonding. Several metrics are investigated such as impedance, displacement/current gain, velocity/current gain, displacement/voltage gain and velocity/voltage gain. The experimental and theoretical research methods include Bode plots, admittance loops, laser vibrometry and coupled-field finite element analysis.

  20. Various diffusion magnetic resonance imaging techniques for pancreatic cancer

    PubMed Central

    Tang, Meng-Yue; Zhang, Xiao-Ming; Chen, Tian-Wu; Huang, Xiao-Hua

    2015-01-01

    Pancreatic cancer is one of the most common malignant tumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging (MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging (DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed. PMID:26753059

  1. Imaging Techniques in Endodontics: An Overview

    PubMed Central

    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

  2. Access Techniques for Document Image Databases.

    ERIC Educational Resources Information Center

    Walker, Frank L.; Thoma, George R.

    1990-01-01

    Describes access and retrieval techniques implemented as part of a research and development program in electronic imaging applied to document storage and retrieval at the National Library of Medicine. Design considerations for large image databases are discussed. (six references) (EAM)

  3. Recent Advancements in Microwave Imaging Plasma Diagnostics

    SciTech Connect

    H. Park; C.C. Chang; B.H. Deng; C.W. Domier; A.J.H. Donni; K. Kawahata; C. Liang; X.P. Liang; H.J. Lu; N.C. Luhmann, Jr.; A. Mase; H. Matsuura; E. Mazzucato; A. Miura; K. Mizuno; T. Munsat; K. and Y. Nagayama; M.J. van de Pol; J. Wang; Z.G. Xia; W-K. Zhang

    2002-03-26

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented.

  4. Advanced x-ray imaging spectrometer

    NASA Technical Reports Server (NTRS)

    Callas, John L. (Inventor); Soli, George A. (Inventor)

    1998-01-01

    An x-ray spectrometer that also provides images of an x-ray source. Coded aperture imaging techniques are used to provide high resolution images. Imaging position-sensitive x-ray sensors with good energy resolution are utilized to provide excellent spectroscopic performance. The system produces high resolution spectral images of the x-ray source which can be viewed in any one of a number of specific energy bands.

  5. Microscopy imaging device with advanced imaging properties

    SciTech Connect

    Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

    2015-11-24

    Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

  6. Advanced and Conventional Magnetic Resonance Imaging in Neuropsychiatric Lupus.

    PubMed

    Sarbu, Nicolae; Bargalló, Núria; Cervera, Ricard

    2015-01-01

    Neuropsychiatric lupus is a major diagnostic challenge, and a main cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is, by far, the main tool for assessing the brain in this disease. Conventional and advanced MRI techniques are used to help establishing the diagnosis, to rule out alternative diagnoses, and recently, to monitor the evolution of the disease. This review explores the neuroimaging findings in SLE, including the recent advances in new MRI methods. PMID:26236469

  7. Advanced and Conventional Magnetic Resonance Imaging in Neuropsychiatric Lupus

    PubMed Central

    Sarbu, Nicolae; Bargalló, Núria; Cervera, Ricard

    2015-01-01

    Neuropsychiatric lupus is a major diagnostic challenge, and a main cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is, by far, the main tool for assessing the brain in this disease. Conventional and advanced MRI techniques are used to help establishing the diagnosis, to rule out alternative diagnoses, and recently, to monitor the evolution of the disease. This review explores the neuroimaging findings in SLE, including the recent advances in new MRI methods. PMID:26236469

  8. ADVANCES IN MOLECULAR IMAGING OF PANCREATIC BETA CELLS

    PubMed Central

    Lin, Mai; Lubag, Angelo; McGuire, Michael J.; Seliounine, Serguei Y.; Tsyganov, Edward N.; Antich, Peter P.; Sherry, A. Dean; Brown, Kathlynn C.; Sun, Xiankai

    2009-01-01

    The development of non-invasive imaging methods for early diagnosis of the beta cell associated metabolic diseases, including type 1 and type 2 diabetes (T1D and T2D), has recently drawn considerable interest from the molecular imaging community as well as clinical investigators. Due to the challenges imposed by the location of the pancreas, the sparsely dispersed beta cell population within the pancreas, and the poor understanding of the pathogenesis of the diseases, clinical diagnosis of beta cell abnormalities is still limited. Current diagnostic methods are invasive, often inaccurate, and usually performed post-onset of the disease. Advances in imaging techniques for probing beta cell mass and function are needed to address this critical health care problem. A variety of currently available imaging techniques have been tested for the assessment of the pancreatic beta cell islets. Here we discuss the current advances in magnetic resonance imaging (MRI), bioluminescence imaging (BLI), and nuclear imaging for the study of beta cell diseases. Spurred by early successes in nuclear imaging techniques for beta cells, especially positron emission tomography (PET), the need for beta cell specific ligands has expanded. Progress in the field for obtaining such ligands is presented. Additionally, we report our preliminary efforts of developing such a peptidic ligand for PET imaging of the pancreatic beta cells. PMID:18508529

  9. Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose

    PubMed Central

    Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

    2015-01-01

    Objectives To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. Methods 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Results Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. Conclusion Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels. PMID:26288186

  10. Recent advances in ophthalmic molecular imaging.

    PubMed

    Ramos de Carvalho, J Emanuel; Verbraak, Frank D; Aalders, Maurice C; van Noorden, Cornelis J; Schlingemann, Reinier O

    2014-01-01

    The aim of molecular imaging techniques is the visualization of molecular processes and functional changes in living animals and human patients before morphological changes occur at the cellular and tissue level. Ophthalmic molecular imaging is still in its infancy and has mainly been used in small animals for pre-clinical research. The goal of most of these pre-clinical studies is their translation into ophthalmic molecular imaging techniques in clinical care. We discuss various molecular imaging techniques and their applications in ophthalmology. PMID:24529711

  11. Advanced Atmospheric Sounder and Imaging Radiometer (AASIR)

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Design information for the Advanced Atmospheric Sounder and Imaging Radiometer is reported, which was developed to determine the configuration of a sensor for IR and visible imaging. The areas of technology reported include: systems design, optics, mechanics, electronics, detectors, radiative cooler, and radiometric calibration.

  12. Advanced Imaging Algorithms for Radiation Imaging Systems

    SciTech Connect

    Marleau, Peter

    2015-10-01

    The intent of the proposed work, in collaboration with University of Michigan, is to develop the algorithms that will bring the analysis from qualitative images to quantitative attributes of objects containing SNM. The first step to achieving this is to develop an indepth understanding of the intrinsic errors associated with the deconvolution and MLEM algorithms. A significant new effort will be undertaken to relate the image data to a posited three-dimensional model of geometric primitives that can be adjusted to get the best fit. In this way, parameters of the model such as sizes, shapes, and masses can be extracted for both radioactive and non-radioactive materials. This model-based algorithm will need the integrated response of a hypothesized configuration of material to be calculated many times. As such, both the MLEM and the model-based algorithm require significant increases in calculation speed in order to converge to solutions in practical amounts of time.

  13. Recent advances in echocardiography: strain and strain rate imaging

    PubMed Central

    Mirea, Oana; Duchenne, Jurgen; Voigt, Jens-Uwe

    2016-01-01

    Deformation imaging by echocardiography is a well-established research tool which has been gaining interest from clinical cardiologists since the introduction of speckle tracking. Post-processing of echo images to analyze deformation has become readily available at the fingertips of the user. New parameters such as global longitudinal strain have been shown to provide added diagnostic value, and ongoing efforts of the imaging societies and industry aimed at harmonizing methods will improve the technique further. This review focuses on recent advances in the field of echocardiographic strain and strain rate imaging, and provides an overview on its current and potential future clinical applications. PMID:27158476

  14. Advanced MR Imaging of the Visual Pathway.

    PubMed

    Yu, Fang; Duong, Timothy; Tantiwongkosi, Bundhit

    2015-08-01

    Vision is one of our most vital senses, deriving from the eyes as well as structures deep within the intracranial compartment. MR imaging, through its wide selection of sequences, offers an array of structural and functional imaging tools to interrogate this intricate system. This review describes several advanced MR imaging sequences and explores their potential clinical applications as well as areas for further development. PMID:26208415

  15. Three dimensional scattering center imaging techniques

    NASA Technical Reports Server (NTRS)

    Younger, P. R.; Burnside, W. D.

    1991-01-01

    Two methods to image scattering centers in 3-D are presented. The first method uses 2-D images generated from Inverse Synthetic Aperture Radar (ISAR) measurements taken by two vertically offset antennas. This technique is shown to provide accurate 3-D imaging capability which can be added to an existing ISAR measurement system, requiring only the addition of a second antenna. The second technique uses target impulse responses generated from wideband radar measurements from three slightly different offset antennas. This technique is shown to identify the dominant scattering centers on a target in nearly real time. The number of measurements required to image a target using this technique is very small relative to traditional imaging techniques.

  16. Advances in optical imaging for pharmacological studies

    PubMed Central

    Arranz, Alicia; Ripoll, Jorge

    2015-01-01

    Imaging approaches are an essential tool for following up over time representative parameters of in vivo models, providing useful information in pharmacological studies. Main advantages of optical imaging approaches compared to other imaging methods are their safety, straight-forward use and cost-effectiveness. A main drawback, however, is having to deal with the presence of high scattering and high absorption in living tissues. Depending on how these issues are addressed, three different modalities can be differentiated: planar imaging (including fluorescence and bioluminescence in vivo imaging), optical tomography, and optoacoustic approaches. In this review we describe the latest advances in optical in vivo imaging with pharmacological applications, with special focus on the development of new optical imaging probes in order to overcome the strong absorption introduced by different tissue components, especially hemoglobin, and the development of multimodal imaging systems in order to overcome the resolution limitations imposed by scattering. PMID:26441646

  17. Earth Observing-1 Advanced Land Imager: Radiometric Response Calibration

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Lencioni, D. E.; Evans, J. B.

    2000-01-01

    The Advanced Land Imager (ALI) is one of three instruments to be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). ALI contains a number of innovative features, including a wide field of view optical design, compact multispectral focal plane arrays, non-cryogenic HgCdTe detectors for the short wave infrared bands, and silicon carbide optics. This document outlines the techniques adopted during ground calibration of the radiometric response of the Advanced Land Imager. Results from system level measurements of the instrument response, signal-to-noise ratio, saturation radiance, and dynamic range for all detectors of every spectral band are also presented.

  18. [Interventional MR imaging: state of the art and technological advances].

    PubMed

    Viard, R; Rousseau, J

    2008-01-01

    Due to its excellent soft tissue contrast and lack of ionizing radiation, MR imaging is well suited for interventional procedures. MRI is being increasingly used for guidance during percutaneous procedures or surgery. Technical advances in interventional MR imaging are reviewed in this paper. Ergonomical factors with improved access to patients as well as advances in informatics, electronics and robotics largely explain this increasing role. Different elements are discussed from improved access to patients in the scanners to improved acquisition pulse sequences. Selected clinical applications and recent publications will be presented to illustrate the current status of this technique. PMID:18288022

  19. Recent advances in 3D computed tomography techniques for simulation and navigation in hepatobiliary pancreatic surgery.

    PubMed

    Uchida, Masafumi

    2014-04-01

    A few years ago it could take several hours to complete a 3D image using a 3D workstation. Thanks to advances in computer science, obtaining results of interest now requires only a few minutes. Many recent 3D workstations or multimedia computers are equipped with onboard 3D virtual patient modeling software, which enables patient-specific preoperative assessment and virtual planning, navigation, and tool positioning. Although medical 3D imaging can now be conducted using various modalities, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography (US) among others, the highest quality images are obtained using CT data, and CT images are now the most commonly used source of data for 3D simulation and navigation image. If the 2D source image is bad, no amount of 3D image manipulation in software will provide a quality 3D image. In this exhibition, the recent advances in CT imaging technique and 3D visualization of the hepatobiliary and pancreatic abnormalities are featured, including scan and image reconstruction technique, contrast-enhanced techniques, new application of advanced CT scan techniques, and new virtual reality simulation and navigation imaging. PMID:24464989

  20. Recent advances in liver imaging.

    PubMed

    Mutter, D; Soler, L; Marescaux, J

    2010-10-01

    Liver surgery remains a difficult challenge in which preoperative data analysis and strategy definition may play a significant role in the success of the procedure. Medical image processing led to a major improvement of patient care by guiding the surgical gesture. From this initial data, new technologies of virtual reality and augmented reality can increase the potential of such images. The 3D modeling of the liver of patients from their CT scan or MRI thus allows an improved surgical planning. Simulation allows the procedure to be simulated preoperatively and offers the opportunity to train the surgical gesture before carrying it out. These three preoperative steps can be used intraoperatively thanks to the development of augmented reality, which consists of superimposing the preoperative 3D modeling of the patient onto the real intraoperative view of the patient and his/her organs. Augmented reality provides surgeons with a transparent view of the patient. This facilitated the intraoperative identification of the vascular anatomy and the control of the segmental arteries and veins in liver surgery, thus preventing intraoperative bleeding. It can also offer guidance due to the virtual improvement of their real surgical tools, which are tracked in real-time during the procedure. During the surgical procedure, augmented reality, therefore, offers surgeons a transparent view of their patient, which will lead to the automation of the most complex maneuvers. The new ways of processing and analyzing liver images have dramatically changed the approach to liver surgery. PMID:20932146

  1. Chemical Approaches for Advanced Optical Imaging

    NASA Astrophysics Data System (ADS)

    Chen, Zhixing

    Advances in optical microscopy have been constantly expanding our knowledge of biological systems. The achievements therein are a result of close collaborations between physicists/engineers who build the imaging instruments and chemists/biochemists who design the corresponding probe molecules. In this work I present a number of chemical approaches for the development of advanced optical imaging methods. Chapter 1 provides an overview of the recent advances of novel imaging approaches taking advantage of chemical tag technologies. Chapter 2 describes the second-generation covalent trimethoprim-tag as a viable tool for live cell protein-specific labeling and imaging. In Chapter 3 we present a fluorescence lifetime imaging approach to map protein-specific micro-environment in live cells using TMP-Cy3 as a chemical probe. In Chapter 4, we present a method harnessing photo-activatable fluorophores to extend the fundamental depth limit in multi-photon microscopy. Chapter 5 describes the development of isotopically edited alkyne palette for multi-color live cell vibrational imaging of cellular small molecules. These studies exemplify the impact of modern chemical approaches in the development of advanced optical microscopies.

  2. Electronic imaging system and technique

    DOEpatents

    Bolstad, Jon O.

    1987-01-01

    A method and system for viewing objects obscurred by intense plasmas or flames (such as a welding arc) includes a pulsed light source to illuminate the object, the peak brightness of the light reflected from the object being greater than the brightness of the intense plasma or flame; an electronic image sensor for detecting a pulsed image of the illuminated object, the sensor being operated as a high-speed shutter; and electronic means for synchronizing the shutter operation with the pulsed light source.

  3. Electronic imaging system and technique

    DOEpatents

    Bolstad, J.O.

    1984-06-12

    A method and system for viewing objects obscurred by intense plasmas or flames (such as a welding arc) includes a pulsed light source to illuminate the object, the peak brightness of the light reflected from the object being greater than the brightness of the intense plasma or flame; an electronic image sensor for detecting a pulsed image of the illuminated object, the sensor being operated as a high-speed shutter; and electronic means for synchronizing the shutter operation with the pulsed light source.

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

    NASA Technical Reports Server (NTRS)

    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.

  5. An accurate registration technique for distorted images

    NASA Technical Reports Server (NTRS)

    Delapena, Michele; Shaw, Richard A.; Linde, Peter; Dravins, Dainis

    1990-01-01

    Accurate registration of International Ultraviolet Explorer (IUE) images is crucial because the variability of the geometrical distortions that are introduced by the SEC-Vidicon cameras ensures that raw science images are never perfectly aligned with the Intensity Transfer Functions (ITFs) (i.e., graded floodlamp exposures that are used to linearize and normalize the camera response). A technique for precisely registering IUE images which uses a cross correlation of the fixed pattern that exists in all raw IUE images is described.

  6. Advanced Microwave/Millimeter-Wave Imaging Technology

    NASA Astrophysics Data System (ADS)

    Shen, Zuowei; Yang, Lu; Luhmann, N. C., Jr.; Domier, C. W.; Ito, N.; Kogi, Y.; Liang, Y.; Mase, A.; Park, H.; Sakata, E.; Tsai, W.; Xia, Z. G.; Zhang, P.

    Millimeter wave technology advances have made possible active and passive millimeter wave imaging for a variety of applications including advanced plasma diagnostics, radio astronomy, atmospheric radiometry, concealed weapon detection, all-weather aircraft landing, contraband goods detection, harbor navigation/surveillance in fog, highway traffic monitoring in fog, helicopter and automotive collision avoidance in fog, and environmental remote sensing data associated with weather, pollution, soil moisture, oil spill detection, and monitoring of forest fires, to name but a few. The primary focus of this paper is on technology advances which have made possible advanced imaging and visualization of magnetohydrodynamic (MHD) fluctuations and microturbulence in fusion plasmas. Topics of particular emphasis include frequency selective surfaces, planar Schottky diode mixer arrays, electronically controlled beam shaping/steering arrays, and high power millimeter wave local oscillator and probe sources.

  7. Advanced technology development for image gathering, coding, and processing

    NASA Technical Reports Server (NTRS)

    Huck, Friedrich O.

    1990-01-01

    Three overlapping areas of research activities are presented: (1) Information theory and optimal filtering are extended to visual information acquisition and processing. The goal is to provide a comprehensive methodology for quantitatively assessing the end-to-end performance of image gathering, coding, and processing. (2) Focal-plane processing techniques and technology are developed to combine effectively image gathering with coding. The emphasis is on low-level vision processing akin to the retinal processing in human vision. (3) A breadboard adaptive image-coding system is being assembled. This system will be used to develop and evaluate a number of advanced image-coding technologies and techniques as well as research the concept of adaptive image coding.

  8. Advances in procedural techniques--antegrade.

    PubMed

    Wilson, William; Spratt, James C

    2014-05-01

    There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the "hybrid' approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited "interventional" collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

  9. Image processing technique for arbitrary image positioning in holographic stereogram

    NASA Astrophysics Data System (ADS)

    Kang, Der-Kuan; Yamaguchi, Masahiro; Honda, Toshio; Ohyama, Nagaaki

    1990-12-01

    In a one-step holographic stereogram, if the series of original images are used just as they are taken from perspective views, three-dimensional images are usually reconstructed in back of the hologram plane. In order to enhance the sense of perspective of the reconstructed images and minimize blur of the interesting portions, we introduce an image processing technique for making a one-step flat format holographic stereogram in which three-dimensional images can be observed at an arbitrary specified position. Experimental results show the effect of the image processing. Further, we show results of a medical application using this image processing.

  10. Advanced Imaging of Chiari 1 Malformations.

    PubMed

    Fakhri, Akbar; Shah, Manish N; Goyal, Manu S

    2015-10-01

    Type I Chiari malformations are congenital deformities involving cerebellar tonsillar herniation downward through the foramen magnum. Structurally, greater than 5 mm of tonsillar descent in adults and more than 6 mm in children is consistent with type I Chiari malformations. However, the radiographic severity of the tonsillar descent does not always correlate well with the clinical symptomatology. Advanced imaging can help clinically correlate imaging to symptoms. Specifically, cerebrospinal fluid (CSF) flow abnormalities are seen in patients with type I Chiari malformation. Advanced MRI involving cardiac-gated and phase-contrast MRI affords a view of such CSF flow abnormalities. PMID:26408061

  11. Labeling of virus components for advanced, quantitative imaging analyses.

    PubMed

    Sakin, Volkan; Paci, Giulia; Lemke, Edward A; Müller, Barbara

    2016-07-01

    In recent years, investigation of virus-cell interactions has moved from ensemble measurements to imaging analyses at the single-particle level. Advanced fluorescence microscopy techniques provide single-molecule sensitivity and subdiffraction spatial resolution, allowing observation of subviral details and individual replication events to obtain detailed quantitative information. To exploit the full potential of these techniques, virologists need to employ novel labeling strategies, taking into account specific constraints imposed by viruses, as well as unique requirements of microscopic methods. Here, we compare strengths and limitations of various labeling methods, exemplify virological questions that were successfully addressed, and discuss challenges and future potential of novel approaches in virus imaging. PMID:26987299

  12. How have developments in molecular imaging techniques furthered schizophrenia research?

    PubMed Central

    Thompson, Judy L; Urban, Nina; Abi-Dargham, Anissa

    2010-01-01

    Molecular imaging techniques have led to significant advances in understanding the pathophysiology of schizophrenia and contributed to knowledge regarding potential mechanisms of action of the drugs used to treat this illness. The aim of this article is to provide a review of the major findings related to the application of molecular imaging techniques that have furthered schizophrenia research. This article focuses specifically on neuroreceptor imaging studies with PET and SPECT. After providing a brief overview of neuroreceptor imaging methodology, we consider relevant findings from studies of receptor availability, and dopamine synthesis and release. Results are discussed in the context of current hypotheses regarding neurochemical alterations in the illness. We then selectively review pharmacological occupancy studies and the role of neuroreceptor imaging in drug development for schizophrenia. PMID:21243081

  13. A comparison of image inpainting techniques

    NASA Astrophysics Data System (ADS)

    Liu, Yaojie; Shu, Chang

    2015-03-01

    Image inpainting is an important research topic in the field of image processing. The objective of inpainting is to "guess" the lost information according to surrounding image information, which can be applied in old photo restoration, object removal and demosaicing. Based on the foundation of previous literature of image inpainting and image modeling, this paper provides an overview of the state-of-art image inpainting methods. This survey first covers mathematics models of inpainting and different kinds of image impairment. Then it goes to the main components of an image, the structure and the texture, and states how these inpainting models and algorithms deal with the two separately, using PDE's method, exemplar-based method and etc. Afterwards sparse-representation-based inpainting and related techniques are introduced. Experimental analysis will be presented to evaluate the relative merits of different algorithms, with the measure of Peak Signal to Noise Ratio (PSNR) as well as direct visual perception.

  14. Bringing Advanced Computational Techniques to Energy Research

    SciTech Connect

    Mitchell, Julie C

    2012-11-17

    Please find attached our final technical report for the BACTER Institute award. BACTER was created as a graduate and postdoctoral training program for the advancement of computational biology applied to questions of relevance to bioenergy research.

  15. Reconstruction techniques for optoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Frenz, Martin; Koestli, Kornel P.; Paltauf, Guenther; Schmidt-Kloiber, Heinz; Weber, Heinz P.

    2001-06-01

    Optoacoustics is a method to gain information from inside a tissue. This is done by irradiating a tissue with a short light pulse, which generates a pressure distribution inside the tissue that mirrors the absorber distribution. The pressure distribution measured on the tissue-surface allows, by applying a back-projection method, to calculate a tomography image of the absorber distribution. This study presents a novel computational algorithm based on Fourier transform, which, at least in principle, yields an exact 3D reconstruction of the distribution of absorbed energy density inside turbid media. The reconstruction is based on 2D pressure distributions captured outside at different times. The FFT reconstruction algorithm is first tested in the back projection of simulated pressure transients of small model absorbers, and finally applied to reconstruct the distribution of artificial blood vessels in three dimensions.

  16. Advanced imaging research and development at DARPA

    NASA Astrophysics Data System (ADS)

    Dhar, Nibir K.; Dat, Ravi

    2012-06-01

    Advances in imaging technology have huge impact on our daily lives. Innovations in optics, focal plane arrays (FPA), microelectronics and computation have revolutionized camera design. As a result, new approaches to camera design and low cost manufacturing is now possible. These advances are clearly evident in visible wavelength band due to pixel scaling, improvements in silicon material and CMOS technology. CMOS cameras are available in cell phones and many other consumer products. Advances in infrared imaging technology have been slow due to market volume and many technological barriers in detector materials, optics and fundamental limits imposed by the scaling laws of optics. There is of course much room for improvements in both, visible and infrared imaging technology. This paper highlights various technology development projects at DARPA to advance the imaging technology for both, visible and infrared. Challenges and potentials solutions are highlighted in areas related to wide field-of-view camera design, small pitch pixel, broadband and multiband detectors and focal plane arrays.

  17. Uncooled thermal imaging sensor and application advances

    NASA Astrophysics Data System (ADS)

    Norton, Peter W.; Cox, Stephen; Murphy, Bob; Grealish, Kevin; Joswick, Mike; Denley, Brian; Feda, Frank; Elmali, Loriann; Kohin, Margaret

    2006-05-01

    BAE Systems continues to advance the technology and performance of microbolometer-based thermal imaging modules and systems. 640x480 digital uncooled infrared focal plane arrays are in full production, illustrated by recent production line test data for two thousand focal plane arrays. This paper presents a snapshot of microbolometer technology at BAE Systems and an overview of two of the most important thermal imaging sensor programs currently in production: a family of thermal weapons sights for the United States Army and a thermal imager for the remote weapons station on the Stryker vehicle.

  18. Utilizing image processing techniques to compute herbivory.

    PubMed

    Olson, T E; Barlow, V M

    2001-01-01

    Leafy spurge (Euphorbia esula L. sensu lato) is a perennial weed species common to the north-central United States and southern Canada. The plant is a foreign species toxic to cattle. Spurge infestation can reduce cattle carrying capacity by 50 to 75 percent [1]. University of Wyoming Entomology doctoral candidate Vonny Barlow is conducting research in the area of biological control of leafy spurge via the Aphthona nigriscutis Foudras flea beetle. He is addressing the question of variability within leafy spurge and its potential impact on flea beetle herbivory. One component of Barlow's research consists of measuring the herbivory of leafy spurge plant specimens after introducing adult beetles. Herbivory is the degree of consumption of the plant's leaves and was measured in two different manners. First, Barlow assigned each consumed plant specimen a visual rank from 1 to 5. Second, image processing techniques were applied to "before" and "after" images of each plant specimen in an attempt to more accurately quantify herbivory. Standardized techniques were used to acquire images before and after beetles were allowed to feed on plants for a period of 12 days. Matlab was used as the image processing tool. The image processing algorithm allowed the user to crop the portion of the "before" image containing only plant foliage. Then Matlab cropped the "after" image with the same dimensions, converted the images from RGB to grayscale. The grayscale image was converted to binary based on a user defined threshold value. Finally, herbivory was computed based on the number of black pixels in the "before" and "after" images. The image processing results were mixed. Although, this image processing technique depends on user input and non-ideal images, the data is useful to Barlow's research and offers insight into better imaging systems and processing algorithms. PMID:11347423

  19. Accuracy test procedure for image evaluation techniques.

    PubMed

    Jones, R A

    1968-01-01

    A procedure has been developed to determine the accuracy of image evaluation techniques. In the procedure, a target having orthogonal test arrays is photographed with a high quality optical system. During the exposure, the target is subjected to horizontal linear image motion. The modulation transfer functions of the images in the horizontal and vertical directions are obtained using the evaluation technique. Since all other degradations are symmetrical, the quotient of the two modulation transfer functions represents the modulation transfer function of the experimentally induced linear image motion. In an accurate experiment, any discrepancy between the experimental determination and the true value is due to inaccuracy in the image evaluation technique. The procedure was used to test the Perkin-Elmer automated edge gradient analysis technique over the spatial frequency range of 0-200 c/m. This experiment demonstrated that the edge gradient technique is accurate over this region and that the testing procedure can be controlled with the desired accuracy. Similarly, the test procedure can be used to determine the accuracy of other image evaluation techniques. PMID:20062421

  20. Imaging for understanding speech communication: Advances and challenges

    NASA Astrophysics Data System (ADS)

    Narayanan, Shrikanth

    2005-04-01

    Research in speech communication has relied on a variety of instrumentation methods to illuminate details of speech production and perception. One longstanding challenge has been the ability to examine real-time changes in the shaping of the vocal tract; a goal that has been furthered by imaging techniques such as ultrasound, movement tracking, and magnetic resonance imaging. The spatial and temporal resolution afforded by these techniques, however, has limited the scope of the investigations that could be carried out. In this talk, we focus on some recent advances in magnetic resonance imaging that allow us to perform near real-time investigations on the dynamics of vocal tract shaping during speech. Examples include Demolin et al. (2000) (4-5 images/second, ultra-fast turbo spin echo) and Mady et al. (2001,2002) (8 images/second, T1 fast gradient echo). A recent study by Narayanan et al. (2004) that used a spiral readout scheme to accelerate image acquisition has allowed for image reconstruction rates of 24 images/second. While these developments offer exciting prospects, a number of challenges lie ahead, including: (1) improving image acquisition protocols, hardware for enhancing signal-to-noise ratio, and optimizing spatial sampling; (2) acquiring quality synchronized audio; and (3) analyzing and modeling image data including cross-modality registration. [Work supported by NIH and NSF.

  1. Advances in Small Animal Imaging Systems

    NASA Astrophysics Data System (ADS)

    Loudos, George K.

    2007-11-01

    The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to an increased interest in in vivo laboratory animal imaging during the past few years. For this purpose, new instrumentation, data acquisition strategies, and image processing and reconstruction techniques are being developed, researched and evaluated. The aim of this article is to give a short overview of the state of the art technologies for high resolution and high sensitivity molecular imaging techniques, primarily positron emission tomography (PET) and single photon emission computed tomography (SPECT). The basic needs of small animal imaging will be described. The evolution in instrumentation in the past two decades, as well as the commercially available systems will be overviewed. Finally, the new trends in detector technology and preliminary results from challenging applications will be presented. For more details a number of references are provided.

  2. Advances in Small Animal Imaging Systems

    SciTech Connect

    Loudos, George K.

    2007-11-26

    The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to an increased interest in in vivo laboratory animal imaging during the past few years. For this purpose, new instrumentation, data acquisition strategies, and image processing and reconstruction techniques are being developed, researched and evaluated. The aim of this article is to give a short overview of the state of the art technologies for high resolution and high sensitivity molecular imaging techniques, primarily positron emission tomography (PET) and single photon emission computed tomography (SPECT). The basic needs of small animal imaging will be described. The evolution in instrumentation in the past two decades, as well as the commercially available systems will be overviewed. Finally, the new trends in detector technology and preliminary results from challenging applications will be presented. For more details a number of references are provided.

  3. Image processing techniques for digital orthophotoquad production

    USGS Publications Warehouse

    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.

  4. Advanced imaging and visualization in gastrointestinal disorders

    PubMed Central

    Gilja, Odd Helge; Hatlebakk, Jan G; Ødegaard, Svein; Berstad, Arnold; Viola, Ivan; Giertsen, Christopher; Hausken, Trygve; Gregersen, Hans

    2007-01-01

    Advanced medical imaging and visualization has a strong impact on research and clinical decision making in gastroenterology. The aim of this paper is to show how imaging and visualization can disclose structural and functional abnormalities of the gastrointestinal (GI) tract. Imaging methods such as ultrasonography, magnetic resonance imaging (MRI), endoscopy, endosonography, and elastography will be outlined and visualization with Virtual Reality and haptic methods. Ultrasonography is a versatile method that can be used to evaluate antral contractility, gastric emptying, transpyloric flow, gastric configuration, intragastric distribution of meals, gastric accommodation and strain measurement of the gastric wall. Advanced methods for endoscopic ultrasound, three-dimensional (3D) ultrasound, and tissue Doppler (Strain Rate Imaging) provide detailed information of the GI tract. Food hypersensitivity reactions including gastrointestinal reactions due to food allergy can be visualized by ultrasonography and MRI. Development of multi-parametric and multi-modal imaging may increase diagnostic benefits and facilitate fusion of diagnostic and therapeutic imaging in the future. PMID:17457973

  5. Superresolution imaging: a survey of current techniques

    NASA Astrophysics Data System (ADS)

    Cristóbal, G.; Gil, E.; Šroubek, F.; Flusser, J.; Miravet, C.; Rodríguez, F. B.

    2008-08-01

    Imaging plays a key role in many diverse areas of application, such as astronomy, remote sensing, microscopy, and tomography. Owing to imperfections of measuring devices (e.g., optical degradations, limited size of sensors) and instability of the observed scene (e.g., object motion, media turbulence), acquired images can be indistinct, noisy, and may exhibit insuffcient spatial and temporal resolution. In particular, several external effects blur images. Techniques for recovering the original image include blind deconvolution (to remove blur) and superresolution (SR). The stability of these methods depends on having more than one image of the same frame. Differences between images are necessary to provide new information, but they can be almost unperceivable. State-of-the-art SR techniques achieve remarkable results in resolution enhancement by estimating the subpixel shifts between images, but they lack any apparatus for calculating the blurs. In this paper, after introducing a review of current SR techniques we describe two recently developed SR methods by the authors. First, we introduce a variational method that minimizes a regularized energy function with respect to the high resolution image and blurs. In this way we establish a unifying way to simultaneously estimate the blurs and the high resolution image. By estimating blurs we automatically estimate shifts with subpixel accuracy, which is inherent for good SR performance. Second, an innovative learning-based algorithm using a neural architecture for SR is described. Comparative experiments on real data illustrate the robustness and utilization of both methods.

  6. Advanced technologies for remote sensing imaging applications

    SciTech Connect

    Wood, L.L.

    1993-06-07

    Generating and returning imagery from great distances has been generally associated with national security activities, with emphasis on reliability of system operation. (While the introduction of such capabilities was usually characterized by high levels of innovation, the evolution of such systems has followed the classical track of proliferation of ``standardized items`` expressing ever more incremental technological advances.) Recent focusing of interest on the use of remote imaging systems for commercial and scientific purposes can be expected to induce comparatively rapid advances along the axes of efficiency and technological sophistication, respectively. This paper reviews the most basic reasons for expecting the next decade of advances to dwarf the impressive accomplishments of the past ten years. The impact of these advances clearly will be felt in all major areas of large-scale human endeavor, commercial, military and scientific.

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

    PubMed Central

    Kim, Minjae

    2016-01-01

    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. PMID:27587949

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

    PubMed

    Kim, Minjae; Kim, Ho Sung

    2016-01-01

    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. PMID:27587949

  9. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss "small-group apprenticeships (SGAs)" as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments…

  10. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research.

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  11. Comparison of image compression techniques for high quality based on properties of visual perception

    NASA Astrophysics Data System (ADS)

    Algazi, V. Ralph; Reed, Todd R.

    1991-12-01

    The growing interest and importance of high quality imaging has several roots: Imaging and graphics, or more broadly multimedia, as the predominant means of man-machine interaction on computers, and the rapid maturing of advanced television technology. Because of their economic importance, proposed advanced television standards are being discussed and evaluated for rapid adoption. These advanced standards are based on well known image compression techniques, used for very low bit rate video communications as well. In this paper, we examine the expected improvement in image quality that advanced television and imaging techniques should bring about. We then examine and discuss the data compression techniques which are commonly used, to determine if they are capable of providing the achievable gain in quality, and to assess some of their limitations. We also discuss briefly the potential of these techniques for very high quality imaging and display applications, which extend beyond the range of existing and proposed television standards.

  12. Imaging Techniques for Relativistic Beams: Issues and Limitations

    SciTech Connect

    Lumpkin, Alex H.; Wendt, Manfred; /Fermilab

    2012-02-01

    Characterizations of transverse profiles for low-power beams in the accelerators of the proposed linear colliders (ILC and CLIC) using imaging techniques are being evaluated. Assessments of the issues and limitations for imaging relativistic beams with intercepting scintillator or optical transition radiation screens are presented based on low-energy tests at the Fermilab A0 photoinjector and are planned for the Advanced Superconducting Test Accelerator at Fermilab. We have described several of the issues and limitations one encounters with the imaging of relativistic electron beams. We have reported our initial tests at the A0PI facility and our plans to extend these studies to the GeV scale at the ASTA facility. We also have plans to test these concepts with 23-GeV beams at the FACET facility at SLAC in the coming year. It appears the future remains bright for imaging techniques in ILC-relevant parameter space.

  13. Advanced laser systems for photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Klosner, Marc; Sampathkumar, Ashwin; Chan, Gary; Wu, Chunbai; Gross, Daniel; Heller, Donald F.

    2015-03-01

    We describe the ongoing development of laser systems for advanced photoacoustic imaging (PAI). We discuss the characteristics of these laser systems and their particular benefits for soft tissue imaging and next-generation breast cancer diagnostics. We provide an overview of laser performance and compare this with other laser systems that have been used for early-stage development of PAI. These advanced systems feature higher pulse energy output at clinically relevant repetition rates, as well as a novel wavelength-cycling output pulse format. Wavelength cycling provides pulse sequences for which the output repeatedly alternates between two wavelengths that provide differential imaging. This capability improves co-registration of captured differential images. We present imaging results of phantoms obtained with a commercial ultrasound detector system and a wavelength-cycling laser source providing ~500 mJ/pulse at 755 and 797 nm, operating at 25 Hz. The results include photoacoustic images and corresponding pulse-echo data from a tissue mimicking phantom containing inclusions, simulating tumors in the breast. We discuss the application of these systems to the contrast-enhanced detection of various tissue types and tumors.

  14. Ultrasonic imaging techniques for breast cancer detection.

    SciTech Connect

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

    2006-01-01

    Improving the resolution and specificity of current ultrasonic imaging technology can enhance its relevance to detection of early-stage breast cancers. Ultrasonic evaluation of breast lesions is desirable because it is quick, inexpensive, and does not expose the patient to potentially harmful ionizing radiation. 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 mortality, morbidity, and remission percentages. In this work, a novel ultrasonic imaging reconstruction method that exploits straight-ray migration is described. This technique, commonly used in seismic imaging, accounts for scattering more accurately than standard ultrasonic approaches, thus providing superior image resolution. A breast phantom with various inclusions is imaged using a pulse-echo approach. The data are processed using the ultrasonic migration method and results are compared to standard linear ultrasound and to x-ray computed tomography (CT) scans. For an ultrasonic frequency of 2.25 MHz, imaged inclusions and features of approximately 1mm are resolved, although better resolution is expected with minor modifications. 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 briefly discussed.

  15. Advances in the Rising Bubble Technique for discharge measurement

    NASA Astrophysics Data System (ADS)

    Hilgersom, Koen; Luxemburg, Willem; Willemsen, Geert; Bussmann, Luuk

    2014-05-01

    Already in the 19th century, d'Auria described a discharge measurement technique that applies floats to find the depth-integrated velocity (d'Auria, 1882). The basis of this technique was that the horizontal distance that the float travels on its way to the surface is the image of the integrated velocity profile over depth. Viol and Semenov (1964) improved this method by using air bubbles as floats, but still distances were measured manually until Sargent (1981) introduced a technique that could derive the distances from two photographs simultaneously taken from each side of the river bank. Recently, modern image processing techniques proved to further improve the applicability of the method (Hilgersom and Luxemburg, 2012). In the 2012 article, controlling and determining the rising velocity of an air bubble still appeared a major challenge for the application of this method. Ever since, laboratory experiments with different nozzle and tube sizes lead to advances in our self-made equipment enabling us to produce individual air bubbles with a more constant rising velocity. Also, we introduced an underwater camera to on-site determine the rising velocity, which is dependent on the water temperature and contamination, and therefore is site-specific. Camera measurements of the rising velocity proved successful in a laboratory and field setting, although some improvements to the setup are necessary to capture the air bubbles also at depths where little daylight penetrates. References D'Auria, L.: Velocity of streams; A new method to determine correctly the mean velocity of any perpendicular in rivers and canals, (The) American Engineers, 3, 1882. Hilgersom, K.P. and Luxemburg, W.M.J.: Technical Note: How image processing facilitates the rising bubble technique for discharge measurement, Hydrology and Earth System Sciences, 16(2), 345-356, 2012. Sargent, D.: Development of a viable method of stream flow measurement using the integrating float technique, Proceedings of

  16. Geometric assessment of image quality using digital image registration techniques

    NASA Technical Reports Server (NTRS)

    Tisdale, G. E.

    1976-01-01

    Image registration techniques were developed to perform a geometric quality assessment of multispectral and multitemporal image pairs. Based upon LANDSAT tapes, accuracies to a small fraction of a pixel were demonstrated. Because it is insensitive to the choice of registration areas, the technique is well suited to performance in an automatic system. It may be implemented at megapixel-per-second rates using a commercial minicomputer in combination with a special purpose digital preprocessor.

  17. An advanced image analysis tool for the quantification and characterization of breast cancer in microscopy images.

    PubMed

    Goudas, Theodosios; Maglogiannis, Ilias

    2015-03-01

    The paper presents an advanced image analysis tool for the accurate and fast characterization and quantification of cancer and apoptotic cells in microscopy images. The proposed tool utilizes adaptive thresholding and a Support Vector Machines classifier. The segmentation results are enhanced through a Majority Voting and a Watershed technique, while an object labeling algorithm has been developed for the fast and accurate validation of the recognized cells. Expert pathologists evaluated the tool and the reported results are satisfying and reproducible. PMID:25681102

  18. Recent Advances in Beam Diagnostic Techniques

    NASA Astrophysics Data System (ADS)

    Fiorito, R. B.

    2002-12-01

    We describe recent advances in diagnostics of the transverse phase space of charged particle beams. The emphasis of this paper is on the utilization of beam-based optical radiation for the precise measurement of the spatial distribution, divergence and emittance of relativistic charged particle beams. The properties and uses of incoherent as well as coherent optical transition, diffraction and synchrotron radiation for beam diagnosis are discussed.

  19. Comparison of various enhanced radar imaging techniques

    NASA Astrophysics Data System (ADS)

    Gupta, Inder J.; Gandhe, Avinash

    1998-09-01

    Recently, many techniques have been proposed to enhance the quality of radar images obtained using SAR and/or ISAR. These techniques include spatially variant apodization (SVA), adaptive sidelobe reduction (ASR), the Capon method, amplitude and phase estimation of sinusoids (APES) and data extrapolation. SVA is a special case of ASR; whereas the APES algorithm is similar to the Capon method except that it provides a better amplitude estimate. In this paper, the ASR technique, the APES algorithm and data extrapolation are used to generate radar images of two experimental targets and an airborne target. It is shown that although for ideal situations (point targets) the APES algorithm provides the best radar images (reduced sidelobe level and sharp main lobe), its performance degrades quickly for real world targets. The ASR algorithm gives radar images with low sidelobes but at the cost of some loss of information about the target. Also, there is not much improvement in radar image resolution. Data extrapolation, on the other hand, improves image resolution. In this case one can reduce the sidelobes by using non-uniform weights. Any loss in the radar image resolution due to non-uniform weights can be compensated by further extrapolating the scattered field data.

  20. Update on imaging techniques in oculoplastics

    PubMed Central

    Cetinkaya, Altug

    2012-01-01

    Imaging is a beneficial aid to the oculoplastic surgeon especially in orbital and lacrimal disorders when the pathology is not visible from outside. It is a powerful tool that may be benefited in not only diagnosis but also management and follow-up. The most common imaging modalities required are CT and MRI, with CT being more frequently ordered by oculoplastic surgeons. Improvements in technology enabled the acquisition times to shorten incredibly. Radiologists can now obtain images with superb resolution, and isolate the site and tissue of interest from other structures with special techniques. Better contrast agents and 3D imaging capabilities make complicated cases easier to identify. Color Doppler imaging is becoming more popular both for research and clinical purposes. Magnetic resonance angiography (MRA) added so much to the vascular system imaging recently. Although angiography is still the gold standard, new software and techniques rendered MRA as valuable as angiography in most circumstances. Stereotactic navigation, although in use for a long time, recently became the focus of interest for the oculoplastic surgeon especially in orbital decompressions. Improvements in radiology and nuclear medicine techniques of lacrimal drainage system imaging provided more detailed analysis of the system. PMID:23961020

  1. Terahertz Tools Advance Imaging for Security, Industry

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Picometrix, a wholly owned subsidiary of Advanced Photonix Inc. (API), of Ann Arbor, Michigan, invented the world s first commercial terahertz system. The company improved the portability and capabilities of their systems through Small Business Innovation Research (SBIR) agreements with Langley Research Center to provide terahertz imaging capabilities for inspecting the space shuttle external tanks and orbiters. Now API s systems make use of the unique imaging capacity of terahertz radiation on manufacturing floors, for thickness measurements of coatings, pharmaceutical tablet production, and even art conservation.

  2. Light and sound - emerging imaging techniques for inflammatory bowel disease

    PubMed Central

    Knieling, Ferdinand; Waldner, Maximilian J

    2016-01-01

    Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography. PMID:27433080

  3. Light and sound - emerging imaging techniques for inflammatory bowel disease.

    PubMed

    Knieling, Ferdinand; Waldner, Maximilian J

    2016-07-01

    Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography. PMID:27433080

  4. A summary of image segmentation techniques

    NASA Technical Reports Server (NTRS)

    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

  5. The use of optical imaging techniques in the gastrointestinal tract

    PubMed Central

    Beg, Sabina; Wilson, Ana; Ragunath, Krish

    2016-01-01

    With significant advances in the management of gastrointestinal disease there has been a move from diagnosing advanced pathology, to detecting early lesions that are potentially amenable to curative endoscopic treatment. This has required an improvement in diagnostics, with a focus on identifying and characterising subtle mucosal changes. There is great interest in the use of optical technologies to predict histology and enable the formulation of a real-time in vivo diagnosis, a so-called ‘optical biopsy’. The aim of this review is to explore the evidence for the use of the current commercially available imaging techniques in the gastrointestinal tract. PMID:27429735

  6. Electrostatic Capacitive Imaging: A New NDE Technique

    NASA Astrophysics Data System (ADS)

    Diamond, G.; Hutchins, D. A.; Leong, K. K.; Gan, T. H.

    2007-03-01

    A new technique for NDE has been developed which is capable of imaging a wide range of materials and structures, ranging from insulators to metallic conductors. The approach, known as Capacitive Imaging (CI) uses electrode arrays in air to produce an AC electric field distribution within the material. Scanning the electrodes over the material causes a change in the field distribution, and hence changes in output voltage. Capacitive coupling allows the technique to work on a wide variety of material conductivities without some of the disadvantages associated with conventional eddy current and potential drop methods. Images are presented of carbon fibre composite materials, concrete and Plexiglas, illustrating the range of application in NDE. The effect of electrode shape and excitation frequency will be discussed in terms of image resolution and depth of penetration.

  7. Advances in laparoscopic urologic surgery techniques

    PubMed Central

    Abdul-Muhsin, Haidar M.; Humphreys, Mitchell R.

    2016-01-01

    The last two decades witnessed the inception and exponential implementation of key technological advancements in laparoscopic urology. While some of these technologies thrived and became part of daily practice, others are still hindered by major challenges. This review was conducted through a comprehensive literature search in order to highlight some of the most promising technologies in laparoscopic visualization, augmented reality, and insufflation. Additionally, this review will provide an update regarding the current status of single-site and natural orifice surgery in urology. PMID:27134743

  8. Advances in laparoscopic urologic surgery techniques.

    PubMed

    Abdul-Muhsin, Haidar M; Humphreys, Mitchell R

    2016-01-01

    The last two decades witnessed the inception and exponential implementation of key technological advancements in laparoscopic urology. While some of these technologies thrived and became part of daily practice, others are still hindered by major challenges. This review was conducted through a comprehensive literature search in order to highlight some of the most promising technologies in laparoscopic visualization, augmented reality, and insufflation. Additionally, this review will provide an update regarding the current status of single-site and natural orifice surgery in urology. PMID:27134743

  9. Red Fluorescent Proteins: Advanced Imaging Applications and Future Design

    PubMed Central

    Shcherbakova, Daria M.; Subach, Oksana M.; Verkhusha, Vladislav V.

    2015-01-01

    In the past few years a large series of the advanced red-shifted fluorescent proteins (RFPs) has been developed. These enhanced RFPs provide new possibilities to study biological processes at the levels ranging from single molecules to whole organisms. Herein the relationship between the properties of the RFPs of different phenotypes and their applications to various imaging techniques are described. Existing and emerging imaging approaches are discussed for conventional RFPs, far-red FPs, RFPs with a large Stokes shift, fluorescent timers, irreversibly photoactivatable and reversibly photo-switchable RFPs. Advantages and limitations of specific RFPs for each technique are presented. Recent progress in understanding the chemical transformations of red chromophores allows the future RFP phenotypes and their respective novel imaging applications to be foreseen. PMID:22851529

  10. Imaging through scattering media by interferometric techniques

    NASA Astrophysics Data System (ADS)

    Tai, A. M.; Aleksoff, C. C.; Chang, B. J.

    1981-07-01

    It is shown that while holographic techniques are effective in seeing through such scattering media as fog, their usefulness in field applications is limited by the requirement of a separate reference beam. An alternative interferometric technique that uses a grating interferometric imaging system is presented, whose main advantage is a relatively high tolerance to normal vibration and air disturbances. It is proposed that the system incorporate a recording device that combines an image converter-intensifier with a real time light modulator. In addition to permitting real time operation, such a device would also increase system sensitivity and permit the use of IR illumination.

  11. Retinal Image Simulation of Subjective Refraction Techniques.

    PubMed

    Perches, Sara; Collados, M Victoria; Ares, Jorge

    2016-01-01

    Refraction techniques make it possible to determine the most appropriate sphero-cylindrical lens prescription to achieve the best possible visual quality. Among these techniques, subjective refraction (i.e., patient's response-guided refraction) is the most commonly used approach. In this context, this paper's main goal is to present a simulation software that implements in a virtual manner various subjective-refraction techniques--including Jackson's Cross-Cylinder test (JCC)--relying all on the observation of computer-generated retinal images. This software has also been used to evaluate visual quality when the JCC test is performed in multifocal-contact-lens wearers. The results reveal this software's usefulness to simulate the retinal image quality that a particular visual compensation provides. Moreover, it can help to gain a deeper insight and to improve existing refraction techniques and it can be used for simulated training. PMID:26938648

  12. Advanced Imaging Modalities in the Detection of Cerebral Vasospasm

    PubMed Central

    Mills, Jena N.; Mehta, Vivek; Russin, Jonathan; Amar, Arun P.; Rajamohan, Anandh; Mack, William J.

    2013-01-01

    The pathophysiology of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is complex and is not entirely understood. Mechanistic insights have been gained through advances in the capabilities of diagnostic imaging. Core techniques have focused on the assessment of vessel caliber, tissue metabolism, and/or regional perfusion parameters. Advances in imaging have provided clinicians with a multifaceted approach to assist in the detection of cerebral vasospasm and the diagnosis of delayed ischemic neurologic deficits (DIND). However, a single test or algorithm with broad efficacy remains elusive. This paper examines both anatomical and physiological imaging modalities applicable to post-SAH vasospasm and offers a historical background. We consider cerebral blood flow velocities measured by Transcranial Doppler Ultrasonography (TCD). Structural imaging techniques, including catheter-based Digital Subtraction Angiography (DSA), CT Angiography (CTA), and MR Angiography (MRA), are reviewed. We examine physiologic assessment by PET, HMPAO SPECT, 133Xe Clearance, Xenon-Enhanced CT (Xe/CT), Perfusion CT (PCT), and Diffusion-Weighted/MR Perfusion Imaging. Comparative advantages and limitations are discussed. PMID:23476766

  13. Diagnostic imaging advances in murine models of colitis

    PubMed Central

    Brückner, Markus; Lenz, Philipp; Mücke, Marcus M; Gohar, Faekah; Willeke, Peter; Domagk, Dirk; Bettenworth, Dominik

    2016-01-01

    Inflammatory bowel diseases (IBD) such as Crohn’s disease and ulcerative colitis are chronic-remittent inflammatory disorders of the gastrointestinal tract still evoking challenging clinical diagnostic and therapeutic situations. Murine models of experimental colitis are a vital component of research into human IBD concerning questions of its complex pathogenesis or the evaluation of potential new drugs. To monitor the course of colitis, to the present day, classical parameters like histological tissue alterations or analysis of mucosal cytokine/chemokine expression often require euthanasia of animals. Recent advances mean revolutionary non-invasive imaging techniques for in vivo murine colitis diagnostics are increasingly available. These novel and emerging imaging techniques not only allow direct visualization of intestinal inflammation, but also enable molecular imaging and targeting of specific alterations of the inflamed murine mucosa. For the first time, in vivo imaging techniques allow for longitudinal examinations and evaluation of intra-individual therapeutic response. This review discusses the latest developments in the different fields of ultrasound, molecularly targeted contrast agent ultrasound, fluorescence endoscopy, confocal laser endomicroscopy as well as tomographic imaging with magnetic resonance imaging, computed tomography and fluorescence-mediated tomography, discussing their individual limitations and potential future diagnostic applications in the management of human patients with IBD. PMID:26811642

  14. Red flag imaging techniques in Barrett's esophagus.

    PubMed

    Saxena, Payal; Canto, Marcia Irene

    2013-07-01

    The key to detection and treatment of early neoplasia in Barrett's esophagus (BE) is thorough and careful inspection of the Barrett's segment. The greatest role for red flag techniques is to help identify neoplastic lesions for targeted biopsy and therapy. High-definition white light endoscopy (HD-WLE) can potentially improve endoscopic imaging of BE compared with standard endoscopy, but little scientific evidence supports this. The addition of autofluorescence imaging to HD-WLE and narrow band imaging increases sensitivity and the false-positive rate without significantly improving overall detection of BE-related neoplasia. PMID:23735101

  15. Image stabilization for SWIR advanced optoelectronic device

    NASA Astrophysics Data System (ADS)

    Schiopu, Paul; Manea, Adrian; Cristea, Ionica; Grosu, Neculai; Craciun, Anca-Ileana; Craciun, Alexandru; Granciu, Dana

    2015-02-01

    At long ranges and under low visibility conditions, Advanced Optoelectronic Device provides the signal-to-noise ratio and image quality in the Short-wave Infra-red - SWIR (wavelengths between 1,1 ÷2,5 μm), significantly better than in the near wave infrared - NWIR and visible spectral bands [1,2]. The quality of image is nearly independent of the polarization in the incoming light, but it is influenced by the relative movement between the optical system and the observer (the operators' handshake), and the movement towards the support system (land and air vehicles). All these make it difficult to detect objectives observation in real time. This paper presents some systems enhance which the ability of observation and sighting through the optical systems without the use of the stands, tripods or other means. We have to eliminate the effect of "tremors of the hands" and the vibration in order to allow the use of optical devices by operators on the moving vehicles on land, on aircraft, or on boats, and to provide additional comfort for the user to track the moving object through the optical system, without losing the control in the process of detection and tracking. The practical applications of stabilization image process, in SWIR, are the most advanced part of the optical observation systems available worldwide [3,4,5]. This application has a didactic nature, because it ensures understanding by the students about image stabilization and their participation in research.

  16. Advances in noninvasive imaging of melanoma.

    PubMed

    Menge, Tyler D; Pellacani, Giovanni

    2016-03-01

    Melanoma is the most dangerous type of skin cancer and its incidence has risen sharply in recent decades. Early detection of disease is critical for improving patient outcomes. Any pigmented lesion that is clinically concerning must be removed by biopsy for morphologic investigation on histology. However, biopsies are invasive and can cause significant morbidity, and their accuracy in detecting melanoma may be limited by sampling error. The advent of noninvasive imaging devices has allowed for assessment of intact skin, thereby minimizing the need for biopsy; and these technologies are increasingly being used in the diagnosis and management of melanoma. Reflectance confocal microscopy, optical coherence tomography, ultrasonography, and multispectral imaging are noninvasive imaging techniques that have emerged as diagnostic aids to physical exam and/or conventional dermoscopy. This review summarizes the current knowledge about these techniques and discusses their practical applications and limitations. PMID:26963113

  17. Functional knee assessment with advanced imaging.

    PubMed

    Amano, Keiko; Li, Qi; Ma, C Benjamin

    2016-06-01

    The purpose of anterior cruciate ligament (ACL) reconstruction is to restore the native stability of the knee joint and to prevent further injury to meniscus and cartilage, yet studies have suggested that joint laxity remains prevalent in varying degrees after ACL reconstruction. Imaging can provide measurements of translational and rotational motions of the tibiofemoral joint that may be too small to detect in routine physical examinations. Various imaging modalities, including fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI), have emerged as powerful methods in measuring the minute details involved in joint biomechanics. While each technique has its own strengths and limitations, they have all enhanced our understanding of the knee joint under various stresses and movements. Acquiring the knowledge of the complex and dynamic motions of the knee after surgery would help lead to improved surgical techniques and better patient outcomes. PMID:27052009

  18. Angular Differential Imaging: a Powerful High-Contrast Imaging Technique

    SciTech Connect

    Marois, C; Lafreniere, D; Doyon, R; Macintosh, B; Nadeau, D

    2005-11-07

    Angular differential imaging is a high-contrast imaging technique that reduces speckle noise from quasi-static optical aberrations and facilitates the detection of faint nearby companions. A sequence of images is acquired with an altitude/azimuth telescope, the instrument rotator being turned off. This keeps the instrument and telescope optics aligned, stabilizes the instrumental PSF and allows the field of view to rotate with respect to the instrument. For each image, a reference PSF obtained from other images of the sequence is subtracted. All residual images are then rotated to align the field and are median combined. Observed performances are reported for Gemini Altair/NIRI data. Inside the speckle dominated region of the PSF, it is shown that quasi-static PSF noise can be reduced by a factor {approx}5 for each image subtraction. The combination of all residuals then provides an additional gain of the order of the square root of the total number of images acquired. To our knowledge, this is the first time an acquisition strategy and reduction pipeline designed for speckle attenuation and high contrast imaging is demonstrated to significantly get better detection limits with longer integration times at all angular separations. A PSF noise attenuation of 100 was achieved from 2-hour long sequences of images of Vega, reaching a 5-sigma contrast of 20 magnitudes for separations greater than 7''. This technique can be used with currently available instruments to search for {approx} 1 M{sub Jup} exoplanets with orbits of radii between 50 and 300 AU around nearby young stars. The possibility of combining the technique with other high-contrast imaging methods is briefly discussed.

  19. Imaging techniques for assaying lymphocyte activation in action

    PubMed Central

    Balagopalan, Lakshmi; Sherman, Eilon; Barr, Valarie A.; Samelson, Lawrence E.

    2012-01-01

    Imaging techniques have greatly improved our understanding of lymphocyte activation. Technical advances in spatial and temporal resolution and new labelling tools have enabled researchers to directly observe the activation process. Consequently, research using imaging approaches to study lymphocyte activation has expanded, providing an unprecedented level of cellular and molecular detail in the field. As a result, certain models of lymphocyte activation have been verified, others have been revised and yet others have been replaced with new concepts. In this article, we review the current imaging techniques that are used to assess lymphocyte activation in different contexts, from whole animals to single molecules, and discuss the advantages and potential limitations of these methods. PMID:21179118

  20. Recent advances in image-guided targeted prostate biopsy.

    PubMed

    Brown, Anna M; Elbuluk, Osama; Mertan, Francesca; Sankineni, Sandeep; Margolis, Daniel J; Wood, Bradford J; Pinto, Peter A; Choyke, Peter L; Turkbey, Baris

    2015-08-01

    Prostate cancer is a common malignancy in the United States that results in over 30,000 deaths per year. The current state of prostate cancer diagnosis, based on PSA screening and sextant biopsy, has been criticized for both overdiagnosis of low-grade tumors and underdiagnosis of clinically significant prostate cancers (Gleason score ≥7). Recently, image guidance has been added to perform targeted biopsies of lesions detected on multi-parametric magnetic resonance imaging (mpMRI) scans. These methods have improved the ability to detect clinically significant cancer, while reducing the diagnosis of low-grade tumors. Several approaches have been explored to improve the accuracy of image-guided targeted prostate biopsy, including in-bore MRI-guided, cognitive fusion, and MRI/transrectal ultrasound fusion-guided biopsy. This review will examine recent advances in these image-guided targeted prostate biopsy techniques. PMID:25596716

  1. Advance crew procedures development techniques: Procedures generation program requirements document

    NASA Technical Reports Server (NTRS)

    Arbet, J. D.; Benbow, R. L.; Hawk, M. L.

    1974-01-01

    The Procedures Generation Program (PGP) is described as an automated crew procedures generation and performance monitoring system. Computer software requirements to be implemented in PGP for the Advanced Crew Procedures Development Techniques are outlined.

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

    NASA Astrophysics Data System (ADS)

    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

  3. Advances in Magnetic Resonance Imaging of the Skull Base

    PubMed Central

    Kirsch, Claudia F.E.

    2014-01-01

    Introduction Over the past 20 years, magnetic resonance imaging (MRI) has advanced due to new techniques involving increased magnetic field strength and developments in coils and pulse sequences. These advances allow increased opportunity to delineate the complex skull base anatomy and may guide the diagnosis and treatment of the myriad of pathologies that can affect the skull base. Objectives The objective of this article is to provide a brief background of the development of MRI and illustrate advances in skull base imaging, including techniques that allow improved conspicuity, characterization, and correlative physiologic assessment of skull base pathologies. Data Synthesis Specific radiographic illustrations of increased skull base conspicuity including the lower cranial nerves, vessels, foramina, cerebrospinal fluid (CSF) leaks, and effacement of endolymph are provided. In addition, MRIs demonstrating characterization of skull base lesions, such as recurrent cholesteatoma versus granulation tissue or abscess versus tumor, are also provided as well as correlative clinical findings in CSF flow studies in a patient pre- and post-suboccipital decompression for a Chiari I malformation. Conclusions This article illustrates MRI radiographic advances over the past 20 years, which have improved clinicians' ability to diagnose, define, and hopefully improve the treatment and outcomes of patients with underlying skull base pathologies. PMID:25992137

  4. Advanced airfoil design empirically based transonic aircraft drag buildup technique

    NASA Technical Reports Server (NTRS)

    Morrison, W. D., Jr.

    1976-01-01

    To systematically investigate the potential of advanced airfoils in advance preliminary design studies, empirical relationships were derived, based on available wind tunnel test data, through which total drag is determined recognizing all major aircraft geometric variables. This technique recognizes a single design lift coefficient and Mach number for each aircraft. Using this technique drag polars are derived for all Mach numbers up to MDesign + 0.05 and lift coefficients -0.40 to +0.20 from CLDesign.

  5. Advanced analysis techniques for uranium assay

    SciTech Connect

    Geist, W. H.; Ensslin, Norbert; Carrillo, L. A.; Beard, C. A.

    2001-01-01

    Uranium has a negligible passive neutron emission rate making its assay practicable only with an active interrogation method. The active interrogation uses external neutron sources to induce fission events in the uranium in order to determine the mass. This technique requires careful calibration with standards that are representative of the items to be assayed. The samples to be measured are not always well represented by the available standards which often leads to large biases. A technique of active multiplicity counting is being developed to reduce some of these assay difficulties. Active multiplicity counting uses the measured doubles and triples count rates to determine the neutron multiplication (f4) and the product of the source-sample coupling ( C ) and the 235U mass (m). Since the 35U mass always appears in the multiplicity equations as the product of Cm, the coupling needs to be determined before the mass can be known. A relationship has been developed that relates the coupling to the neutron multiplication. The relationship is based on both an analytical derivation and also on empirical observations. To determine a scaling constant present in this relationship, known standards must be used. Evaluation of experimental data revealed an improvement over the traditional calibration curve analysis method of fitting the doubles count rate to the 235Um ass. Active multiplicity assay appears to relax the requirement that the calibration standards and unknown items have the same chemical form and geometry.

  6. New techniques in articular cartilage imaging.

    PubMed

    Potter, Hollis G; Black, Brandon R; Chong, Le Roy

    2009-01-01

    Standardized magnetic resonance imaging (MRI) pulse sequences provide an accurate, reproducible assessment of cartilage morphology. Three-dimensional (3D) modeling techniques enable semiautomated models of the joint surface and thickness measurements, which may eventually prove essential in templating before partial or total joint resurfacing as well as focal cartilage repair. Quantitative MRI techniques, such as T2 mapping, T1 rho, and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), provide noninvasive information about cartilage and repair tissue biochemistry. Diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) demonstrate information regarding the regional anisotropic variation of cartilage ultrastructure. Further research strengthening the association between quantitative MRI and cartilage material properties may predict the functional capacity of native and repaired tissue. MRI provides an essential objective assessment of cartilage regenerative procedures. PMID:19064167

  7. [Cucumber diseases diagnosis using multispectral imaging technique].

    PubMed

    Feng, Jie; Liao, Ning-Fang; Zhao, Bo; Luo, Yong-Dao; Li, Bao-Ju

    2009-02-01

    For a reliable diagnosis of plant diseases and insect pests, spectroscopy analysis technique and mutispectral imaging technique are proposed to diagnose five cucumber diseases, namely Trichothecium roseum, Sphaerotheca fuliginea, Cladosporium cucumerinum, Corynespora cassiicola and Pseudoperonospora cubensis. In the experiment, the cucumbers' multispectral images of 14 visible lights channels, near infrared channel and panchromatic channel were captured using narrow-band multispectral imaging system under standard observation environment. And the 5 cucumber diseases, healthy leaves and reference white were classified using their multispectral information, the distance, angle and relativity. The discrimination of Trichothecium roseum, Sphaerotheca fuliginea, Cladosporium cucumerinum, and reference white was 100%, and that of Pseudoperonospora cubensis and healthy leaves was 80% and 93.33% respectively. The mean correct discrimination of diseases was 81.90% when the distance and relativity were used together. The result shows that the method realized good accuracy in the cucumber diseases diagnosis. PMID:19445229

  8. Astronomy helps advance medical diagnosis techniques

    NASA Astrophysics Data System (ADS)

    2001-11-01

    Effective treatment of cancer relies on the early detection and removal of cancerous cells. Unfortunately, this is when they are hardest to spot. In the case of breast cancer, now the most prevalent form of cancer in the United Kingdom, cancer cells tend to congregate in the lymph nodes, from where they can rapidly spread throughout the rest of the body. Current medical equipment can give doctors only limited information on tissue health. A surgeon must then perform an exploratory operation to try to identify the diseased tissue. If that is possible, the diseased tissue will be removed. If identification is not possible, the doctor may be forced to take away the whole of the lymphatic system. Such drastic treatment can then cause side effects, such as excessive weight gain, because it throws the patient's hormones out of balance. Now, members of the Science Payloads Technology Division of the Research and Science Support Department, at ESA's science, technology and engineering research centre (ESTEC) in the Netherlands, have developed a new X-ray camera that could make on-the-spot diagnoses and pinpoint cancerous areas to guide surgeons. Importantly, it would be a small device that could be used continuously during operations. "There is no photography involved in the camera we envisage. It will be completely digital, so the surgeon will study the whole lymphatic system and the potentially cancerous parts on his monitor. He then decides which parts he removes," says Dr. Tone Peacock, Head of the Science Payloads Technology Division. The ESA team were trying to find a way to make images using high-energy X-rays because some celestial objects give out large quantities of X-rays but little visible light. To see these, astronomers need to use X-ray cameras. Traditionally, this has been a bit of a blind spot for astronomers. ESA's current X-ray telescope, XMM-Newton, is in orbit now, observing low energy, so-called 'soft' X-rays. European scientists have always wanted to

  9. Astronomy helps advance medical diagnosis techniques

    NASA Astrophysics Data System (ADS)

    2001-11-01

    Effective treatment of cancer relies on the early detection and removal of cancerous cells. Unfortunately, this is when they are hardest to spot. In the case of breast cancer, now the most prevalent form of cancer in the United Kingdom, cancer cells tend to congregate in the lymph nodes, from where they can rapidly spread throughout the rest of the body. Current medical equipment can give doctors only limited information on tissue health. A surgeon must then perform an exploratory operation to try to identify the diseased tissue. If that is possible, the diseased tissue will be removed. If identification is not possible, the doctor may be forced to take away the whole of the lymphatic system. Such drastic treatment can then cause side effects, such as excessive weight gain, because it throws the patient's hormones out of balance. Now, members of the Science Payloads Technology Division of the Research and Science Support Department, at ESA's science, technology and engineering research centre (ESTEC) in the Netherlands, have developed a new X-ray camera that could make on-the-spot diagnoses and pinpoint cancerous areas to guide surgeons. Importantly, it would be a small device that could be used continuously during operations. "There is no photography involved in the camera we envisage. It will be completely digital, so the surgeon will study the whole lymphatic system and the potentially cancerous parts on his monitor. He then decides which parts he removes," says Dr. Tone Peacock, Head of the Science Payloads Technology Division. The ESA team were trying to find a way to make images using high-energy X-rays because some celestial objects give out large quantities of X-rays but little visible light. To see these, astronomers need to use X-ray cameras. Traditionally, this has been a bit of a blind spot for astronomers. ESA's current X-ray telescope, XMM-Newton, is in orbit now, observing low energy, so-called 'soft' X-rays. European scientists have always wanted to

  10. Advances in brain imaging: a new ethical challenge.

    PubMed

    Alfano, B; Brunetti, A

    1997-01-01

    Technical advances in the past 25 years permitted substantial advances in the neuroimaging field, expanding the diagnostic and research potentials and significantly reducing the use of old invasive imaging techniques for research purposes. The safer procedures now available allow acquisition of reference data, morphological assessment and functional characterisation from healthy volunteers. However, enrollment of volunteers is still a sensitive ethical issue. Ethical problems related to informed consent, for both research and diagnostic procedures, in patients with neuropsychiatric disorders represent an additional crucial issue. Furthermore, with both functional and structural neuroimaging studies, there is a theoretical risk of violation of individual privacy. Research in the neuroimaging field should tend to increase the amount of information obtained through appropriate post-processing procedures, including multimodality image fusion, and to limit stress and discomfort. PMID:9616958

  11. Retinal Image Simulation of Subjective Refraction Techniques

    PubMed Central

    Perches, Sara; Collados, M. Victoria; Ares, Jorge

    2016-01-01

    Refraction techniques make it possible to determine the most appropriate sphero-cylindrical lens prescription to achieve the best possible visual quality. Among these techniques, subjective refraction (i.e., patient’s response-guided refraction) is the most commonly used approach. In this context, this paper’s main goal is to present a simulation software that implements in a virtual manner various subjective-refraction techniques—including Jackson’s Cross-Cylinder test (JCC)—relying all on the observation of computer-generated retinal images. This software has also been used to evaluate visual quality when the JCC test is performed in multifocal-contact-lens wearers. The results reveal this software’s usefulness to simulate the retinal image quality that a particular visual compensation provides. Moreover, it can help to gain a deeper insight and to improve existing refraction techniques and it can be used for simulated training. PMID:26938648

  12. Recent advances in DNA sequencing techniques

    NASA Astrophysics Data System (ADS)

    Singh, Rama Shankar

    2013-06-01

    Successful mapping of the draft human genome in 2001 and more recent mapping of the human microbiome genome in 2012 have relied heavily on the parallel processing of the second generation/Next Generation Sequencing (NGS) DNA machines at a cost of several millions dollars and long computer processing times. These have been mainly biochemical approaches. Here a system analysis approach is used to review these techniques by identifying the requirements, specifications, test methods, error estimates, repeatability, reliability and trends in the cost reduction. The first generation, NGS and the Third Generation Single Molecule Real Time (SMART) detection sequencing methods are reviewed. Based on the National Human Genome Research Institute (NHGRI) data, the achieved cost reduction of 1.5 times per yr. from Sep. 2001 to July 2007; 7 times per yr., from Oct. 2007 to Apr. 2010; and 2.5 times per yr. from July 2010 to Jan 2012 are discussed.

  13. Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques

    NASA Astrophysics Data System (ADS)

    Chung, Kit Man

    Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one

  14. Diagnostics of nonlocal plasmas: advanced techniques

    NASA Astrophysics Data System (ADS)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  15. Advances in Spectral-Spatial Classification of Hyperspectral Images

    NASA Technical Reports Server (NTRS)

    Fauvel, Mathieu; Tarabalka, Yuliya; Benediktsson, Jon Atli; Chanussot, Jocelyn; Tilton, James C.

    2012-01-01

    Recent advances in spectral-spatial classification of hyperspectral images are presented in this paper. Several techniques are investigated for combining both spatial and spectral information. Spatial information is extracted at the object (set of pixels) level rather than at the conventional pixel level. Mathematical morphology is first used to derive the morphological profile of the image, which includes characteristics about the size, orientation and contrast of the spatial structures present in the image. Then the morphological neighborhood is defined and used to derive additional features for classification. Classification is performed with support vector machines using the available spectral information and the extracted spatial information. Spatial post-processing is next investigated to build more homogeneous and spatially consistent thematic maps. To that end, three presegmentation techniques are applied to define regions that are used to regularize the preliminary pixel-wise thematic map. Finally, a multiple classifier system is defined to produce relevant markers that are exploited to segment the hyperspectral image with the minimum spanning forest algorithm. Experimental results conducted on three real hyperspectral images with different spatial and spectral resolutions and corresponding to various contexts are presented. They highlight the importance of spectral-spatial strategies for the accurate classification of hyperspectral images and validate the proposed methods.

  16. Evaluation of Advanced Retrieval Techniques in an Experimental Online Catalog.

    ERIC Educational Resources Information Center

    Larson, Ray R.

    1992-01-01

    Discusses subject searching problems in online library catalogs; explains advanced information retrieval (IR) techniques; and describes experiments conducted on a test collection database, CHESHIRE (California Hybrid Extended SMART for Hypertext and Information Retrieval Experimentation), which was created to evaluate IR techniques in online…

  17. Innovative Tools Advance Revolutionary Weld Technique

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The iconic, orange external tank of the space shuttle launch system not only contains the fuel used by the shuttle s main engines during liftoff but also comprises the shuttle s backbone, supporting the space shuttle orbiter and solid rocket boosters. Given the tank s structural importance and the extreme forces (7.8 million pounds of thrust load) and temperatures it encounters during launch, the welds used to construct the tank must be highly reliable. Variable polarity plasma arc welding, developed for manufacturing the external tank and later employed for building the International Space Station, was until 1994 the best process for joining the aluminum alloys used during construction. That year, Marshall Space Flight Center engineers began experimenting with a relatively new welding technique called friction stir welding (FSW), developed in 1991 by The Welding Institute, of Cambridge, England. FSW differs from traditional fusion welding in that it is a solid-state welding technique, using frictional heat and motion to join structural components without actually melting any of the material. The weld is created by a shouldered pin tool that is plunged into the seam of the materials to be joined. The tool traverses the line while rotating at high speeds, generating friction that heats and softens but does not melt the metal. (The heat produced approaches about 80 percent of the metal s melting temperature.) The pin tool s rotation crushes and stirs the plasticized metal, extruding it along the seam as the tool moves forward. The material cools and consolidates, resulting in a weld with superior mechanical properties as compared to those weld properties of fusion welds. The innovative FSW technology promises a number of attractive benefits. Because the welded materials are not melted, many of the undesirables associated with fusion welding porosity, cracking, shrinkage, and distortion of the weld are minimized or avoided. The process is more energy efficient, safe

  18. Advances in Imaging for Atrial Fibrillation Ablation

    PubMed Central

    D'Silva, Andrew; Wright, Matthew

    2011-01-01

    Over the last fifteen years, our understanding of the pathophysiology of atrial fibrillation (AF) has paved the way for ablation to be utilized as an effective treatment option. With the aim of gaining more detailed anatomical representation, advances have been made using various imaging modalities, both before and during the ablation procedure, in planning and execution. Options have flourished from procedural fluoroscopy, electroanatomic mapping systems, preprocedural computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and combinations of these technologies. Exciting work is underway in an effort to allow the electrophysiologist to assess scar formation in real time. One advantage would be to lessen the learning curve for what are very complex procedures. The hope of these developments is to improve the likelihood of a successful ablation procedure and to allow more patients access to this treatment. PMID:22091384

  19. Evaluation of optical reflectance techniques for imaging of alveolar structure

    NASA Astrophysics Data System (ADS)

    Unglert, Carolin I.; Namati, Eman; Warger, William C.; Liu, Linbo; Yoo, Hongki; Kang, DongKyun; Bouma, Brett E.; Tearney, Guillermo J.

    2012-07-01

    Three-dimensional (3-D) visualization of the fine structures within the lung parenchyma could advance our understanding of alveolar physiology and pathophysiology. Current knowledge has been primarily based on histology, but it is a destructive two-dimensional (2-D) technique that is limited by tissue processing artifacts. Micro-CT provides high-resolution three-dimensional (3-D) imaging within a limited sample size, but is not applicable to intact lungs from larger animals or humans. Optical reflectance techniques offer the promise to visualize alveolar regions of the large animal or human lung with sub-cellular resolution in three dimensions. Here, we present the capabilities of three optical reflectance techniques, namely optical frequency domain imaging, spectrally encoded confocal microscopy, and full field optical coherence microscopy, to visualize both gross architecture as well as cellular detail in fixed, phosphate buffered saline-immersed rat lung tissue. Images from all techniques were correlated to each other and then to corresponding histology. Spatial and temporal resolution, imaging depth, and suitability for in vivo probe development were compared to highlight the merits and limitations of each technology for studying respiratory physiology at the alveolar level.

  20. Image Recognition Techniques for Gamma Spectroscopy

    SciTech Connect

    Vlachos, D. S.; Tsabaris, C. G.

    2007-12-26

    Photons, after generated from a radioactive source and before they deposit their energy in a photo detector, are subsequent to multiple scattering mechanisms. As a result, the measured energy from the photo detector is different from the energy the photon had when generated. This is known as folding of the photon energy. Moreover, statistical fluctuation inside the detector contribute to energy folding. In this work, a new method is presented for unfolding the gamma ray spectrum. The method uses a 2-dimensional representation of the measured spectrum (image) and then uses image recognition techniques, and especially differential edge detection, to generate the original spectrum.

  1. Recent Advances in the Imaging of Frontotemporal Dementia

    PubMed Central

    Whitwell, Jennifer L.; Josephs, Keith A.

    2012-01-01

    Neuroimaging has played an important role in the characterization of the frontotemporal dementia (FTD) syndromes, demonstrating neurodegenerative signatures that can aid in the differentiation of FTD from other neurodegenerative disorders. Recent advances have been driven largely by the refinement of the clinical syndromes that underlie FTD, and by the discovery of new genetic and pathological features associated with FTD. Many new imaging techniques and modalities are also now available that allow the assessment of other aspects of brain structure and function, such as diffusion tensor imaging and resting state functional MRI. Studies have utilized these recent techniques, as well as traditional volumetric MRI, to provide further insight into disease progression across the many clinical, genetic and pathological variants of FTD. Importantly, neuroimaging signatures have been identified that will improve the clinician’s ability to predict underlying genetic and pathological features, and hence ultimately improve patient diagnosis. PMID:23015371

  2. Advanced imaging systems programs at DARPA MTO

    NASA Astrophysics Data System (ADS)

    Dhar, Nibir K.; Elizondo, Lee A.; Dat, Ravi; Elizondo, Shelly L.

    2013-09-01

    In this paper, we review a few selected imaging technology development programs at the Defense Advanced Research Projects Agency (DARPA) in the reflective visible to the emissive/thermal long wave infrared (LWIR) spectral bands. For the reflective visible band, results are shown for two different imagers: a gigapixel monocentric multi-scale camera design that solves the scaling issues for a high pixel count, and a wide field of view and a single photon detection camera with a large dynamic range. Also, a camera with broadband capability covering both reflective and thermal bands (0.5 μm to 5.0 μm) with >80% quantum efficiency is discussed. In the emissive/thermal band, data is presented for both uncooled and cryogenically cooled LWIR detectors with pixel pitches approaching the fundamental detection limits. By developing wafer scale manufacturing processes and reducing the pixel size of uncooled thermal imagers, it is shown that an affordable camera on a chip, capable of seeing through obscurants in day or night, is feasible. Also, the fabrication and initial performance of the world's first 5 μm pixel pitch LWIR camera is discussed. Lastly, we use an initial model to evaluate the signal to noise ratio and noise equivalent differential temperature as a function of well capacity to predict the performance for this thermal imager.

  3. Molecular imaging of rheumatoid arthritis: emerging markers, tools, and techniques

    PubMed Central

    2014-01-01

    Early diagnosis and effective monitoring of rheumatoid arthritis (RA) are important for a positive outcome. Instant treatment often results in faster reduction of inflammation and, as a consequence, less structural damage. Anatomical imaging techniques have been in use for a long time, facilitating diagnosis and monitoring of RA. However, mere imaging of anatomical structures provides little information on the processes preceding changes in synovial tissue, cartilage, and bone. Molecular imaging might facilitate more effective diagnosis and monitoring in addition to providing new information on the disease pathogenesis. A limiting factor in the development of new molecular imaging techniques is the availability of suitable probes. Here, we review which cells and molecules can be targeted in the RA joint and discuss the advances that have been made in imaging of arthritis with a focus on such molecular targets as folate receptor, F4/80, macrophage mannose receptor, E-selectin, intercellular adhesion molecule-1, phosphatidylserine, and matrix metalloproteinases. In addition, we discuss a new tool that is being introduced in the field, namely the use of nanobodies as tracers. Finally, we describe additional molecules displaying specific features in joint inflammation and propose these as potential new molecular imaging targets, more specifically receptor activator of nuclear factor κB and its ligand, chemokine receptors, vascular cell adhesion molecule-1, αVβ3 integrin, P2X7 receptor, suppression of tumorigenicity 2, dendritic cell-specific transmembrane protein, and osteoclast-stimulatory transmembrane protein. PMID:25099015

  4. Imaging spectroscopic analysis at the Advanced Light Source

    SciTech Connect

    MacDowell, A. A.; Warwick, T.; Anders, S.; Lamble, G.M.; Martin, M.C.; McKinney, W.R.; Padmore, H.A.

    1999-05-12

    One of the major advances at the high brightness third generation synchrotrons is the dramatic improvement of imaging capability. There is a large multi-disciplinary effort underway at the ALS to develop imaging X-ray, UV and Infra-red spectroscopic analysis on a spatial scale from. a few microns to 10nm. These developments make use of light that varies in energy from 6meV to 15KeV. Imaging and spectroscopy are finding applications in surface science, bulk materials analysis, semiconductor structures, particulate contaminants, magnetic thin films, biology and environmental science. This article is an overview and status report from the developers of some of these techniques at the ALS. The following table lists all the currently available microscopes at the. ALS. This article will describe some of the microscopes and some of the early applications.

  5. Advanced gastrointestinal endoscopic imaging for inflammatory bowel diseases

    PubMed Central

    Tontini, Gian Eugenio; Rath, Timo; Neumann, Helmut

    2016-01-01

    Gastrointestinal luminal endoscopy is of paramount importance for diagnosis, monitoring and dysplasia surveillance in patients with both, Crohn’s disease and ulcerative colitis. Moreover, with the recent recognition that mucosal healing is directly linked to the clinical outcome of patients with inflammatory bowel disorders, a growing demand exists for the precise, timely and detailed endoscopic assessment of superficial mucosal layer. Further, the novel field of molecular imaging has tremendously expanded the clinical utility and applications of modern endoscopy, now encompassing not only diagnosis, surveillance, and treatment but also the prediction of individual therapeutic responses. Within this review, we describe how novel endoscopic approaches and advanced endoscopic imaging methods such as high definition and high magnification endoscopy, dye-based and dye-less chromoendoscopy, confocal laser endomicroscopy, endocytoscopy and molecular imaging now allow for the precise and ultrastructural assessment of mucosal inflammation and describe the potential of these techniques for dysplasia detection. PMID:26811662

  6. Pork grade evaluation using hyperspectral imaging techniques

    NASA Astrophysics Data System (ADS)

    Zhou, Rui; Cai, Bo; Wang, Shoubing; Ji, Huihua; Chen, Huacai

    2011-11-01

    The method to evaluate the grade of the pork based on hyperspectral imaging techniques was studied. Principal component analysis (PCA) was performed on the hyperspectral image data to extract the principal components which were used as the inputs of the evaluation model. By comparing the different discriminating rates in the calibration set and the validation set under different information, the choice of the components can be optimized. Experimental results showed that the classification evaluation model was the optimal when the principal of component (PC) of spectra was 3, while the corresponding discriminating rate was 89.1% in the calibration set and 84.9% in the validation set. It was also good when the PC of images was 9, while the corresponding discriminating rate was 97.2% in the calibration set and 91.1% in the validation set. The evaluation model based on both information of spectra and images was built, in which the corresponding PCs of spectra and images were used as the inputs. This model performed very well in grade classification evaluation, and the discriminating rates of calibration set and validation set were 99.5% and 92.7%, respectively, which were better than the two evaluation models based on single information of spectra or images.

  7. Research on hyperspectral polarization imaging technique

    NASA Astrophysics Data System (ADS)

    Zhao, Haibo; Feng, Lei; Zhou, Yu; Wang, Zheng; Lin, Xuling

    2015-08-01

    The summary of hyperspectral polarization remote sensing detection is presented, including the characteristics and mechanism of polarization detection, the expression of polarization light and the detection method. The present research of hyperspectral polarization remote sensing is introduced. A novel method of hyperspectral polarization imaging technique is discussed, which is based on static modulation adding with the double refraction crystal. The static modulation is composed of one polarizer and two retarders. The double refraction crystal is used to generate interference image. The four Stokes vectors and spectral information can be detected only by one measurement. The method of static modulation is introduced in detail and is simulated by computer. The experimental system is also established in laboratory. The basic concept of the technique is verified. The simulation error of DOP (polarization degree detection) is about 1%. The experimental error of DOP is less than 5%. The merits of the novel system are no moving parts, compactness and no electrical element.

  8. Lunar surface chemistry: A new imaging technique

    USGS Publications Warehouse

    Andre, C.G.; Bielefeld, M.J.; Eliason, E.; Soderblom, L.A.; Adler, I.; Philpotts, J.A.

    1977-01-01

    Detailed chemical maps of the lunar surface have been constructed by applying a new weighted-filter imaging technique to Apollo 15 and Apollo 16 x-ray fluorescence data. The data quality improvement is amply demonstrated by (i) modes in the frequency distribution, representing highland and mare soil suites, which are not evident before data filtering and (ii) numerous examples of chemical variations which are correlated with small-scale (about 15 kilometer) lunar topographic features.

  9. [Direct and indirect mucosal wave imaging techniques].

    PubMed

    Krasnodębska, Paulina; Szkiełkowska, Agata

    2016-04-01

    The vocal folds play a key role in the process of phonation. Cyclical movements of the vocal folds model a space called glottis, what leads to voice formation. The space contains surface between the vocal folds and the inner surface of the arytenoid cartilages. The best indicator of the vocal folds vibratory function is the mucosal wave. The presence and size of the mucosal wave is widely recognized as an indicator of tension and plasticity of vocal folds. It is also essential in the process of creating a proper, resonant voice. In the article, current knowledge of mucosal wave imaging techniques is given. Imaging can be carried out directly and indirectly. Among the direct methods, the following are distinguished: laryngostroboscopy, laryngovideostroboscopy, videokymography and high-speed digital imaging. Indirect methods include: electroglottography, photoglottography and ultrasonography. PMID:27137829

  10. Biometric Identification Using Holographic Radar Imaging Techniques

    SciTech Connect

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.; Kennedy, Mike O.; Foote, Harlan P.

    2007-04-01

    Pacific Northwest National Laboratory researchers have been at the forefront of developing innovative screening systems to enhance security and a novel imaging system to provide custom-fit clothing using holographic radar imaging techniques. First-of-a-kind cylindrical holographic imaging systems have been developed to screen people at security checkpoints for the detection of concealed, body worn, non-metallic threats such as plastic and liquid explosives, knifes and contraband. Another embodiment of this technology is capable of obtaining full sized body measurements in near real time without the person under surveillance removing their outer garments. Radar signals readily penetrate clothing and reflect off the water in skin. This full body measurement system is commercially available for best fitting ready to wear clothing, which was the first “biometric” application for this technology. One compelling feature of this technology for security biometric applications is that it can see effectively through disguises, appliances and body hair.

  11. Diagnosis by Endoscopy and Advanced Imaging of Barrett's Neoplasia.

    PubMed

    Swager, Anne-Fré; Curvers, Wouter L; Bergman, Jacques J

    2016-01-01

    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 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. PMID:27573768

  12. Diagnostic imaging techniques in thyroid cancer

    SciTech Connect

    Friedman, M.; Toriumi, D.M.; Mafee, M.F.

    1988-02-01

    With the refinement of fine-needle aspiration, the specific applications of thyroid imaging techniques need to be reevaluated for efficiency and cost containment. No thyroid imaging test should be routinely obtained. Radionuclide scanning is most beneficial in evaluating the functional status of thyroid nodules when fine-needle aspiration is inadequate, the findings are benign, or when there is no discrete nodule that is palpated in an enlarged gland. When fine-needle aspiration is unavailable or unreliable, radionuclide scanning becomes a first-line diagnostic tool. Ultrasonography should be used primarily for identifying a solid component of a cystic nodule, determining the size of nodules on thyroxine suppression that are not easily palpable, or for performing guided fine-needle aspiration. Computerized tomography and magnetic resonance imaging both have a definite role in the evaluation of thyroid tumors. Magnetic resonance imaging is superior to computerized tomography for the evaluation of metastatic, retrotracheal, or mediastinal involvement of large thyroid tumors or goiters. Careful selection of the diagnostic techniques will ensure more accurate diagnosis and reduce unnecessary patient costs in the treatment of thyroid cancer.

  13. Advanced Imaging in Femoroacetabular Impingement: Current State and Future Prospects

    PubMed Central

    Bittersohl, Bernd; Hosalkar, Harish S.; Hesper, Tobias; Tiderius, Carl Johan; Zilkens, Christoph; Krauspe, Rüdiger

    2015-01-01

    Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abnormalities and to accurately characterize the chondrolabral damage as much as possible. However, both plain radiographs and computed tomography (CT) are insensitive for articular cartilage anatomy and pathology. Advanced magnetic resonance imaging (MRI) techniques include magnetic resonance arthrography and biochemically sensitive techniques of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho (T1ρ), T2/T2* mapping, and several others. The diagnostic performance of these techniques to evaluate cartilage degeneration could improve the ability to predict an individual patient-specific outcome with non-surgical and surgical care. This review discusses the facts and current applications of biochemical MRI for hip joint cartilage assessment covering the roles of dGEMRIC, T2/T2*, and T1ρ mapping. The basics of each technique and their specific role in FAI assessment are outlined. Current limitations and potential pitfalls as well as future directions of biochemical imaging are also outlined. PMID:26258129

  14. Advanced Imaging in Femoroacetabular Impingement: Current State and Future Prospects.

    PubMed

    Bittersohl, Bernd; Hosalkar, Harish S; Hesper, Tobias; Tiderius, Carl Johan; Zilkens, Christoph; Krauspe, Rüdiger

    2015-01-01

    Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abnormalities and to accurately characterize the chondrolabral damage as much as possible. However, both plain radiographs and computed tomography (CT) are insensitive for articular cartilage anatomy and pathology. Advanced magnetic resonance imaging (MRI) techniques include magnetic resonance arthrography and biochemically sensitive techniques of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho (T1ρ), T2/T2* mapping, and several others. The diagnostic performance of these techniques to evaluate cartilage degeneration could improve the ability to predict an individual patient-specific outcome with non-surgical and surgical care. This review discusses the facts and current applications of biochemical MRI for hip joint cartilage assessment covering the roles of dGEMRIC, T2/T2*, and T1ρ mapping. The basics of each technique and their specific role in FAI assessment are outlined. Current limitations and potential pitfalls as well as future directions of biochemical imaging are also outlined. PMID:26258129

  15. Quantitative Computed Tomography and Image Analysis for Advanced Muscle Assessment

    PubMed Central

    Edmunds, Kyle Joseph; Gíslason, Magnus K.; Arnadottir, Iris D.; Marcante, Andrea; Piccione, Francesco; Gargiulo, Paolo

    2016-01-01

    Medical imaging is of particular interest in the field of translational myology, as extant literature describes the utilization of a wide variety of techniques to non-invasively recapitulate and quantity various internal and external tissue morphologies. In the clinical context, medical imaging remains a vital tool for diagnostics and investigative assessment. This review outlines the results from several investigations on the use of computed tomography (CT) and image analysis techniques to assess muscle conditions and degenerative process due to aging or pathological conditions. Herein, we detail the acquisition of spiral CT images and the use of advanced image analysis tools to characterize muscles in 2D and 3D. Results from these studies recapitulate changes in tissue composition within muscles, as visualized by the association of tissue types to specified Hounsfield Unit (HU) values for fat, loose connective tissue or atrophic muscle, and normal muscle, including fascia and tendon. We show how results from these analyses can be presented as both average HU values and compositions with respect to total muscle volumes, demonstrating the reliability of these tools to monitor, assess and characterize muscle degeneration. PMID:27478562

  16. Recent Advances in Molecular Magnetic Resonance Imaging of Liver Fibrosis

    PubMed Central

    Li, Zhiming; Sun, Jihong; Yang, Xiaoming

    2015-01-01

    Liver fibrosis is a life-threatening disease with high morbidity and mortality owing to its diverse causes. Liver biopsy, as the current gold standard for diagnosing and staging liver fibrosis, has a number of limitations, including sample variability, relatively high cost, an invasive nature, and the potential of complications. Most importantly, in clinical practice, patients often reject additional liver biopsies after initiating treatment despite their being necessary for long-term follow-up. To resolve these problems, a number of different noninvasive imaging-based methods have been developed for accurate diagnosis of liver fibrosis. However, these techniques only reflect morphological or perfusion-related alterations in the liver, and thus they are generally only useful for the diagnosis of late-stage liver fibrosis (liver cirrhosis), which is already characterized by “irreversible” anatomic and hemodynamic changes. Thus, it is essential that new approaches are developed for accurately diagnosing early-stage liver fibrosis as at this stage the disease may be “reversed” by active treatment. The development of molecular MR imaging technology has potential in this regard, as it facilitates noninvasive, target-specific imaging of liver fibrosis. We provide an overview of recent advances in molecular MR imaging for the diagnosis and staging of liver fibrosis and we compare novel technologies with conventional MR imaging techniques. PMID:25874221

  17. Advances in gamma titanium aluminides and their manufacturing techniques

    NASA Astrophysics Data System (ADS)

    Kothari, Kunal; Radhakrishnan, Ramachandran; Wereley, Norman M.

    2012-11-01

    Gamma titanium aluminides display attractive properties for high temperature applications. For over a decade in the 1990s, the attractive properties of titanium aluminides were outweighed by difficulties encountered in processing and machining at room temperature. But advances in manufacturing technologies, deeper understanding of titanium aluminides microstructure, deformation mechanisms, and advances in micro-alloying, has led to the production of gamma titanium aluminide sheets. An in-depth review of key advances in gamma titanium aluminides is presented, including microstructure, deformation mechanisms, and alloy development. Traditional manufacturing techniques such as ingot metallurgy and investment casting are reviewed and advances via powder metallurgy based manufacturing techniques are discussed. Finally, manufacturing challenges facing gamma titanium aluminides, as well as avenues to overcome them, are discussed.

  18. The application of advanced analytical techniques to direct coal liquefaction

    SciTech Connect

    Brandes, S.D.; Winschel, R.A.; Burke, F.P.; Robbins, G.A.

    1991-12-31

    Consol is coordinating a program designed to bridge the gap between the advanced, modern techniques of the analytical chemist and the application of those techniques by the direct coal liquefaction process developer, and to advance our knowledge of the process chemistry of direct coal liquefaction. The program is designed to provide well-documented samples to researchers who are utilizing techniques potentially useful for the analysis of coal derived samples. The choice of samples and techniques was based on an extensive survey made by Consol of the present status of analytical methodology associated with direct coal liquefaction technology. Sources of information included process developers and analytical chemists. Identified in the survey are a number of broadly characterizable needs. These categories include a need for: A better understanding of the nature of the high molecular weight, non-distillable residual materials (both soluble and insoluble) in the process streams; improved techniques for molecular characterization, heteroatom and hydrogen speciation and a knowledge of the hydrocarbon structural changes across coal liquefaction systems; better methods for sample separation; application of advanced data analysis methods; the use of more advanced predictive models; on-line analytical techniques; and better methods for catalyst monitoring.

  19. Advanced liner-cooling techniques for gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Riddlebaugh, S. M.

    1985-01-01

    Component research for advanced small gas turbine engines is currently underway at the NASA Lewis Research Center. As part of this program, a basic reverse-flow combustor geometry was being maintained while different advanced liner wall cooling techniques were investigated. Performance and liner cooling effectiveness of the experimental combustor configuration featuring counter-flow film-cooled panels is presented and compared with two previously reported combustors featuring: splash film-cooled liner walls; and transpiration cooled liner walls (Lamilloy).

  20. [Advanced online search techniques and dedicated search engines for physicians].

    PubMed

    Nahum, Yoav

    2008-02-01

    In recent years search engines have become an essential tool in the work of physicians. This article will review advanced search techniques from the world of information specialists, as well as some advanced search engine operators that may help physicians improve their online search capabilities, and maximize the yield of their searches. This article also reviews popular dedicated scientific and biomedical literature search engines. PMID:18357673

  1. 75 FR 44015 - Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... COMMISSION Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing... importation of certain semiconductor products made by advanced lithography techniques and products containing... certain semiconductor products made by advanced lithography techniques or products containing same...

  2. Optical replication techniques for image slicers

    NASA Astrophysics Data System (ADS)

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

    2006-06-01

    The smart focal planes (SmartFP) activity is an European Joint Research Activity funded to develop novel optical technologies for future large telescope instrumentation [Cunningham C.R., et al., 2004. SPIE 5382, 718-726]. In this paper, we will discuss the image slicer developments being carried out as part of this initiative. Image slicing techniques have many applications in the plans for instrumentation on extremely large telescopes and will be central to the delivery of the science case. A study of a virtual multi-object multi-ifu spectrograph and imager (MOMSI) for a hypothetical OWL-class telescope reveals the need for focal plane splitting, deployable imagers and very small beam steering elements like deployable IFUs. The image slicer workpackage, lead from Durham University in collaboration with LFM Bremen, TNO Delft, UKATC Edinburgh, CRAL Lyon, LAM Marseille, Padua University and REFLEX Prague, is evaluating technologies for manufacturing micro optics in large numbers to enable multi-object integral field spectroscopy.

  3. Multivariate image processing technique for noninvasive glucose sensing

    NASA Astrophysics Data System (ADS)

    Webb, Anthony J.; Cameron, Brent D.

    2010-02-01

    A potential noninvasive glucose sensing technique was investigated for application towards in vivo glucose monitoring for individuals afflicted with diabetes mellitus. Three dimensional ray tracing simulations using a realistic iris pattern integrated into an advanced human eye model are reported for physiological glucose concentrations ranging between 0 to 500 mg/dL. The anterior chamber of the human eye contains a clear fluid known as the aqueous humor. The optical refractive index of the aqueous humor varies on the order of 1.5x10-4 for a change in glucose concentration of 100 mg/dL. The simulation data was analyzed with a developed multivariate chemometrics procedure that utilizes iris-based images to form a calibration model. Results from these simulations show considerable potential for use of the developed method in the prediction of glucose. For further demonstration, an in vitro eye model was developed to validate the computer based modeling technique. In these experiments, a realistic iris pattern was placed in an analog eye model in which the glucose concentration within the fluid representing the aqueous humor was varied. A series of high resolution digital images were acquired using an optical imaging system. These images were then used to form an in vitro calibration model utilizing the same multivariate chemometric technique demonstrated in the 3-D optical simulations. In general, the developed method exhibits considerable applicability towards its use as an in vivo platform for the noninvasive monitoring of physiological glucose concentration.

  4. Advances in image registration and fusion

    NASA Astrophysics Data System (ADS)

    Steer, Christopher; Rogers, Jeremy; Smith, Moira; Heather, Jamie; Bernhardt, Mark; Hickman, Duncan

    2008-03-01

    Many image fusion systems involving passive sensors require the accurate registration of the sensor data prior to performing fusion. Since depth information is not readily available in such systems, all registration algorithms are intrinsically approximations based upon various assumption about the depth field. Although often overlooked, many registration algorithms can break down in certain situations and this may adversely affect the image fusion performance. In this paper, we discuss a framework for quantifying the accuracy and robustness of image registration algorithms which allows a more precise understanding of their shortcomings. In addition, some novel algorithms have been investigated that overcome some of these limitations. A second aspect of this work has considered the treatment of images from multiple sensors whose angular and spatial separation is large and where conventional registration algorithms break down (typically greater than a few degrees of separation). A range of novel approaches is reported which exploit the use of parallax to estimate depth information and reconstruct a geometrical model of the scene. The imagery can then be combined with this geometrical model to render a variety of useful representations of the data. These techniques (which we term Volume Registration) show great promise as a means of gathering and presenting 3D and 4D scene information for both military and civilian applications.

  5. Multispectral laser imaging for advanced food analysis

    NASA Astrophysics Data System (ADS)

    Senni, L.; Burrascano, P.; Ricci, M.

    2016-07-01

    A hardware-software apparatus for food inspection capable of realizing multispectral NIR laser imaging at four different wavelengths is herein discussed. The system was designed to operate in a through-transmission configuration to detect the presence of unwanted foreign bodies inside samples, whether packed or unpacked. A modified Lock-In technique was employed to counterbalance the significant signal intensity attenuation due to transmission across the sample and to extract the multispectral information more efficiently. The NIR laser wavelengths used to acquire the multispectral images can be varied to deal with different materials and to focus on specific aspects. In the present work the wavelengths were selected after a preliminary analysis to enhance the image contrast between foreign bodies and food in the sample, thus identifying the location and nature of the defects. Experimental results obtained from several specimens, with and without packaging, are presented and the multispectral image processing as well as the achievable spatial resolution of the system are discussed.

  6. Robustness of speckle imaging techniques applied to horizontal imaging scenarios

    NASA Astrophysics Data System (ADS)

    Bos, Jeremy P.

    Atmospheric turbulence near the ground severely limits the quality of imagery acquired over long horizontal paths. In defense, surveillance, and border security applications, there is interest in deploying man-portable, embedded systems incorporating image reconstruction to improve the quality of imagery available to operators. To be effective, these systems must operate over significant variations in turbulence conditions while also subject to other variations due to operation by novice users. Systems that meet these requirements and are otherwise designed to be immune to the factors that cause variation in performance are considered robust. In addition to robustness in design, the portable nature of these systems implies a preference for systems with a minimum level of computational complexity. Speckle imaging methods are one of a variety of methods recently been proposed for use in man-portable horizontal imagers. In this work, the robustness of speckle imaging methods is established by identifying a subset of design parameters that provide immunity to the expected variations in operating conditions while minimizing the computation time necessary for image recovery. This performance evaluation is made possible using a novel technique for simulating anisoplanatic image formation. I find that incorporate as few as 15 image frames and 4 estimates of the object phase per reconstructed frame provide an average reduction of 45% reduction in Mean Squared Error (MSE) and 68% reduction in deviation in MSE. In addition, the Knox-Thompson phase recovery method is demonstrated to produce images in half the time required by the bispectrum. Finally, it is shown that certain blind image quality metrics can be used in place of the MSE to evaluate reconstruction quality in field scenarios. Using blind metrics rather depending on user estimates allows for reconstruction quality that differs from the minimum MSE by as little as 1%, significantly reducing the deviation in

  7. Special feature on imaging systems and techniques

    NASA Astrophysics Data System (ADS)

    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

  8. Virtual reality techniques for the visualization of biomedical imaging data

    NASA Astrophysics Data System (ADS)

    Shaw, Maurice A.; Spillman, William B., Jr.; Meissner, Ken E.; Gabbard, Joseph

    2001-07-01

    The Optical Sciences & Engineering Research Center (OSER) at Virginia Polytechnic and State University investigates advanced laser surgery optics, biocompatible material for implants, and diagnostic patches and other diagnostic and drug delivery tools. The Center employs optics to provide new biological research tools for visualization, measurement, analysis and manipulation. The Center's Research into Multispectral Medical Analysis and Visualization techniques will allow human and veterinary medical professionals to diagnose various conditions of the body in much the same way that satellite information is used to study earth resources. Each pixel in the image has an associated spectra. Advanced image analysis techniques are combined with cross-correlation of the spectra with signatures of known conditions, allowing automated diagnostic assistance to physicians. The analysis and visualization system consists of five components: data acquisition, data storage, data standardization, data analysis, and data visualization. OSER research efforts will be directed toward investigations of these system components as an integrated tool for next generation medical diagnostics. OSER will research critical data quality and data storage issues, mult-spectral sensor technologies, data analysis techniques, and diagnostic visualization systems including the VT-CAVE, (www.cave.vt.edu). The VT-CAVE is Virginia Tech's configuration of Fakespace Systems, Inc Virtual Reality system.

  9. Recent advances in morphological cell image analysis.

    PubMed

    Chen, Shengyong; Zhao, Mingzhu; Wu, Guang; Yao, Chunyan; Zhang, Jianwei

    2012-01-01

    This paper summarizes the recent advances in image processing methods for morphological cell analysis. The topic of morphological analysis has received much attention with the increasing demands in both bioinformatics and biomedical applications. Among many factors that affect the diagnosis of a disease, morphological cell analysis and statistics have made great contributions to results and effects for a doctor. Morphological cell analysis finds the cellar shape, cellar regularity, classification, statistics, diagnosis, and so forth. In the last 20 years, about 1000 publications have reported the use of morphological cell analysis in biomedical research. Relevant solutions encompass a rather wide application area, such as cell clumps segmentation, morphological characteristics extraction, 3D reconstruction, abnormal cells identification, and statistical analysis. These reports are summarized in this paper to enable easy referral to suitable methods for practical solutions. Representative contributions and future research trends are also addressed. PMID:22272215

  10. Surface conversion techniques for low energy neutral atom imagers

    NASA Technical Reports Server (NTRS)

    Quinn, J. M.

    1995-01-01

    This investigation has focused on development of key technology elements for low energy neutral atom imaging. More specifically, we have investigated the conversion of low energy neutral atoms to negatively charged ions upon reflection from specially prepared surfaces. This 'surface conversion' technique appears to offer a unique capability of detecting, and thus imaging, neutral atoms at energies of 0.01 - 1 keV with high enough efficiencies to make practical its application to low energy neutral atom imaging in space. Such imaging offers the opportunity to obtain the first instantaneous global maps of macroscopic plasma features and their temporal variation. Through previous in situ plasma measurements, we have a statistical picture of large scale morphology and local measurements of dynamic processes. However, with in situ techniques it is impossible to characterize or understand many of the global plasma transport and energization processes. A series of global plasma images would greatly advance our understanding of these processes and would provide the context for interpreting previous and future in situ measurements. Fast neutral atoms, created from ions that are neutralized in collisions with exospheric neutrals, offer the means for remotely imaging plasma populations. Energy and mass analysis of these neutrals provides critical information about the source plasma distribution. The flux of neutral atoms available for imaging depends upon a convolution of the ambient plasma distribution with the charge exchange cross section for the background neutral population. Some of the highest signals are at relatively low energies (well below 1 keV). This energy range also includes some of the most important plasma populations to be imaged, for example the base of the cleft ion fountain.

  11. Imaging Techniques in Acute Heart Failure.

    PubMed

    Pérez del Villar, Candelas; Yotti, Raquel; Bermejo, Javier

    2015-07-01

    In recent years, imaging techniques have revolutionized the diagnosis of heart failure. In patients with a clinical picture of acute decompensation, prognosis is largely determined by early implementation of general measures and treatment of the underlying cause. Given its diagnostic yield and portability, ultrasound has become an essential tool in the setting of acute heart failure, and is currently found in all medical departments involved in the care of the critically ill patient. Cardiac magnetic resonance and computed tomography allow detailed characterization of multiple aspects of cardiac structure and function that were previously unavailable. This helps guide and monitor many of the treatment decisions in the acute heart failure population in an entirely noninvasive way. This article aims to review the usefulness of the imaging techniques that are clinically relevant in the context of an episode of acute heart failure. We discuss the indications and limitations of these techniques in detail and describe the general principles for the appropriate interpretation of results. PMID:26002273

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

    PubMed Central

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

    2016-01-01

    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. PMID:27602255

  13. Multiresolution segmentation technique for spine MRI images

    NASA Astrophysics Data System (ADS)

    Li, Haiyun; Yan, Chye H.; Ong, Sim Heng; Chui, Cheekong K.; Teoh, Swee H.

    2002-05-01

    In this paper, we describe a hybrid method for segmentation of spinal magnetic resonance imaging that has been developed based on the natural phenomenon of stones appearing as water recedes. The candidate segmentation region corresponds to the stones with characteristics similar to that of intensity extrema, edges, intensity ridge and grey-level blobs. The segmentation method is implemented based on a combination of wavelet multiresolution decomposition and fuzzy clustering. First thresholding is performed dynamically according to local characteristic to detect possible target areas, We then use fuzzy c-means clustering in concert with wavelet multiscale edge detection to identify the maximum likelihood anatomical and functional target areas. Fuzzy C-Means uses iterative optimization of an objective function based on a weighted similarity measure between the pixels in the image and each of c cluster centers. Local extrema of this objective function are indicative of an optimal clustering of the input data. The multiscale edges can be detected and characterized from local maxima of the modulus of the wavelet transform while the noise can be reduced to some extent by enacting thresholds. The method provides an efficient and robust algorithm for spinal image segmentation. Examples are presented to demonstrate the efficiency of the technique on some spinal MRI images.

  14. Novel imaging techniques for diabetic macular edema.

    PubMed

    Lobo, C; Bernardes, R; Faria de Abreu, J R; Cunha-Vaz, J G

    1999-01-01

    Retinal edema should be defined as any increase of water of the retinal tissue resulting in an increase in its volume. It may be of cytotoxic or vasogenic origin. Development of vasogenic macular edema is dependent on a series of factors such as blood pressure, blood-retinal barrier permeability, retinal cell damage, retinal tissue osmotic pressure and retinal tissue compliance. Objective measurements of retinal thickness are now possible using the Retinal Thickness Analyser. Localised measurements of blood-retinal barrier permeability may also be obtained using the Retinal Leakage Analyser, a modified confocal scanning laser fluorometer, while obtaining simultaneously angiographic images of the choroid and retina. These new imaging techniques show that cytotoxic and vasogenic retinal edema may occur independently in the early stages of diabetic retinopathy. These findings offer new perspectives for designing novel therapeutic strategies. PMID:10896349

  15. Atherosclerosis staging: imaging using FLIM technique

    NASA Astrophysics Data System (ADS)

    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.

  16. Technology in radiology: advances in diagnostic imaging & therapeutics.

    PubMed

    Stern, S M

    1993-01-01

    Nearly 100 years from its birth, radiology continues to grow as though still in adolescence. Although some radiologic technologies have matured more than others, new applications and techniques appear regularly in the literature. Radiology has evolved from purely diagnostic devices to interventional technologies. New contrast agents in MRI, X ray and ultrasound enable physicians to make diagnoses and plan therapies with greater precision than ever before. Techniques are less and less invasive. Advances in computer technology have given supercomputer-like power to high-end nuclear medicine and MRI systems. Imaging systems in most modalities are now designed with upgrades in mind instead of "planned obsolescence." Companies routinely upgrade software and other facets of their products, sometimes at no additional charge to existing customers. Hospitals, radiology groups and imaging centers will face increasing demands to justify what they do according to patient outcomes and management criteria. Did images make the diagnosis or confirm it? Did the images determine optimal treatment strategies or confirm which strategies might be appropriate? Third-party payers, especially the government, will view radiology in those terms. The diagnostic imaging and therapy systems of today require increasingly sophisticated technical support for maintenance and repair. Hospitals, radiology groups and imaging centers will have to determine the most economic and effective ways to guarantee equipment up-time. Borrowing from the automotive industry, some radiology manufacturers have devised transtelephonic software systems to facilitate remote troubleshooting. To ensure their fiscal viability, hospitals continue to acquire new imaging and therapy technologies for competitive and access-to-services reasons.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:10129808

  17. Advanced magneto-optical microscopy: Imaging from picoseconds to centimeters - imaging spin waves and temperature distributions (invited)

    NASA Astrophysics Data System (ADS)

    Urs, Necdet Onur; Mozooni, Babak; Mazalski, Piotr; Kustov, Mikhail; Hayes, Patrick; Deldar, Shayan; Quandt, Eckhard; McCord, Jeffrey

    2016-05-01

    Recent developments in the observation of magnetic domains and domain walls by wide-field optical microscopy based on the magneto-optical Kerr, Faraday, Voigt, and Gradient effect are reviewed. Emphasis is given to the existence of higher order magneto-optical effects for advanced magnetic imaging. Fundamental concepts and advances in methodology are discussed that allow for imaging of magnetic domains on various length and time scales. Time-resolved imaging of electric field induced domain wall rotation is shown. Visualization of magnetization dynamics down to picosecond temporal resolution for the imaging of spin-waves and magneto-optical multi-effect domain imaging techniques for obtaining vectorial information are demonstrated. Beyond conventional domain imaging, the use of a magneto-optical indicator technique for local temperature sensing is shown.

  18. Recent advances in radiology and medical imaging

    SciTech Connect

    Steiner, R.E.; Sherwood, T.

    1986-01-01

    The first chapter, on the radiology of arthritis, is an overview. The second and seventh chapters are on the chest the former, on adult respiratory distress syndrome, is a brief summary, and the latter, on digital radiography of the chest with the prototype slit-scanning technique. The third chapter reviews computed tomography of the lumbar spine. The following two chapters are on MR imaging, one on the central nervous system (covering demyelinating diseases, cardiovascular disease, infections, and tumors), with excellent illustrations; and one on MR imaging of the body. The illustrations are good. The following chapter is on extracardiac digital subtraction angiography (DSA), with an interesting table comparing and contrasting conventional angiography with both intraveneous and intraarterial DSA. The eighth chapter on pediatric imaging fits a world of experience. Chapter 9 is an update on contrast media, while the next chapter is on barium infusion examination of the small intestine. The final three chapters are concerned with the present state of angioplasty, interventional radiology in the urinary tract.

  19. Advanced Marketing Core Curriculum. Test Items and Assessment Techniques.

    ERIC Educational Resources Information Center

    Smith, Clifton L.; And Others

    This document contains duties and tasks, multiple-choice test items, and other assessment techniques for Missouri's advanced marketing core curriculum. The core curriculum begins with a list of 13 suggested textbook resources. Next, nine duties with their associated tasks are given. Under each task appears one or more citations to appropriate…

  20. 3D pulmonary airway color image reconstruction via shape from shading and virtual bronchoscopy imaging techniques

    NASA Astrophysics Data System (ADS)

    Suter, Melissa; Reinhardt, Joseph M.; Hoffman, Eric A.; McLennan, Geoffrey

    2005-04-01

    The dependence on macro-optical imaging of the human body in the assessment of possible disease is rapidly increasing concurrent with, and as a direct result of, advancements made in medical imaging technologies. Assessing the pulmonary airways through bronchoscopy is performed extensively in clinical practice however remains highly subjective due to limited visualization techniques and the lack of quantitative analyses. The representation of 3D structures in 2D visualization modes, although providing an insight to the structural content of the scene, may in fact skew the perception of the structural form. We have developed two methods for visualizing the optically derived airway mucosal features whilst preserving the structural scene integrity. Shape from shading (SFS) techniques can be used to extract 3D structural information from 2D optical images. The SFS technique presented addresses many limitations previously encountered in conventional techniques resulting in high-resolution 3D color images. The second method presented to combine both color and structural information relies on combined CT and bronchoscopy imaging modalities. External imaging techniques such as CT provide a means of determining the gross structural anatomy of the pulmonary airways, however lack the important optically derived mucosal color. Virtual bronchoscopy is used to provide a direct link between the CT derived structural anatomy and the macro-optically derived mucosal color. Through utilization of a virtual and true bronchoscopy matching technique we are able to directly extract combined structurally sound 3D color segments of the pulmonary airways. Various pulmonary airway diseases are assessed and the resulting combined color and texture results are presented demonstrating the effectiveness of the presented techniques.

  1. Optical Fourier techniques for medical image processing and phase contrast imaging

    PubMed Central

    Yelleswarapu, Chandra S.; Kothapalli, Sri-Rajasekhar; Rao, D.V.G.L.N.

    2008-01-01

    This paper briefly reviews the basics of optical Fourier techniques (OFT) and applications for medical image processing as well as phase contrast imaging of live biological specimens. Enhancement of microcalcifications in a mammogram for early diagnosis of breast cancer is the main focus. Various spatial filtering techniques such as conventional 4f filtering using a spatial mask, photoinduced polarization rotation in photosensitive materials, Fourier holography, and nonlinear transmission characteristics of optical materials are discussed for processing mammograms. We also reviewed how the intensity dependent refractive index can be exploited as a phase filter for phase contrast imaging with a coherent source. This novel approach represents a significant advance in phase contrast microscopy. PMID:18458764

  2. Optical Fourier techniques for medical image processing and phase contrast imaging.

    PubMed

    Yelleswarapu, Chandra S; Kothapalli, Sri-Rajasekhar; Rao, D V G L N

    2008-04-01

    This paper briefly reviews the basics of optical Fourier techniques (OFT) and applications for medical image processing as well as phase contrast imaging of live biological specimens. Enhancement of microcalcifications in a mammogram for early diagnosis of breast cancer is the main focus. Various spatial filtering techniques such as conventional 4f filtering using a spatial mask, photoinduced polarization rotation in photosensitive materials, Fourier holography, and nonlinear transmission characteristics of optical materials are discussed for processing mammograms. We also reviewed how the intensity dependent refractive index can be exploited as a phase filter for phase contrast imaging with a coherent source. This novel approach represents a significant advance in phase contrast microscopy. PMID:18458764

  3. Advances in imaging ultrastructure yield new insights into presynaptic biology

    PubMed Central

    Bruckner, Joseph J.; Zhan, Hong; O’Connor-Giles, Kate M.

    2015-01-01

    Synapses are the fundamental functional units of neural circuits, and their dysregulation has been implicated in diverse neurological disorders. At presynaptic terminals, neurotransmitter-filled synaptic vesicles are released in response to calcium influx through voltage-gated calcium channels activated by the arrival of an action potential. Decades of electrophysiological, biochemical, and genetic studies have contributed to a growing understanding of presynaptic biology. Imaging studies are yielding new insights into how synapses are organized to carry out their critical functions. The development of techniques for rapid immobilization and preservation of neuronal tissues for electron microscopy (EM) has led to a new renaissance in ultrastructural imaging that is rapidly advancing our understanding of synapse structure and function. PMID:26052269

  4. Glaucoma Diagnosis and Monitoring Using Advanced Imaging Technologies

    PubMed Central

    Sehi, Mitra; Iverson, Shawn M

    2014-01-01

    Advanced ocular imaging technologies facilitate objective and reproducible quantification of change in glaucoma but at the same time, impose new challenges on scientists and clinicians for separating true structural change from imaging noise. This review examines time-domain and spectral-domain optical coherence tomography, confocal scanning laser ophthalmoscopy and scanning laser polarimetry technologies and discusses the diagnostic accuracy and the ability of each technique for evaluation of glaucomatous progression. A broad review of the current literature reveals that objective assessment of retinal nerve fiber layer, ganglion cell complex and optic nerve head topography may improve glaucoma monitoring when used as a complementary tool in conjunction with the clinical judgment of an expert. PMID:24470807

  5. Recent advances in live cell imaging of hepatoma cells

    PubMed Central

    2014-01-01

    Live cell imaging enables the study of dynamic processes of living cells in real time by use of suitable reporter proteins and the staining of specific cellular structures and/or organelles. With the availability of advanced optical devices and improved cell culture protocols it has become a rapidly growing research methodology. The success of this technique relies mainly on the selection of suitable reporter proteins, construction of recombinant plasmids possessing cell type specific promoters as well as reliable methods of gene transfer. This review aims to provide an overview of the recent developments in the field of marker proteins (bioluminescence and fluorescent) and methodologies (fluorescent resonance energy transfer, fluorescent recovery after photobleaching and proximity ligation assay) employed as to achieve an improved imaging of biological processes in hepatoma cells. Moreover, different expression systems of marker proteins and the modes of gene transfer are discussed with emphasis on the study of lipid droplet formation in hepatocytes as an example. PMID:25005127

  6. Fast Imaging Technique for fMRI: Consecutive Multishot Echo Planar Imaging Accelerated with GRAPPA Technique

    PubMed Central

    Kang, Daehun; Sung, Yul-Wan; Kang, Chang-Ki

    2015-01-01

    This study was to evaluate the proposed consecutive multishot echo planar imaging (cmsEPI) combined with a parallel imaging technique in terms of signal-to-noise ratio (SNR) and acceleration for a functional imaging study. We developed cmsEPI sequence using both consecutively acquired multishot EPI segments and variable flip angles to minimize the delay between segments and to maximize the SNR, respectively. We also combined cmsEPI with the generalized autocalibrating partially parallel acquisitions (GRAPPA) method. Temporal SNRs were measured at different acceleration factors and number of segments for functional sensitivity evaluation. We also examined the geometric distortions, which inherently occurred in EPI sequence. The practical acceleration factors, R = 2 or R = 3, of the proposed technique improved the temporal SNR by maximally 18% in phantom test and by averagely 8.2% in in vivo experiment, compared to cmsEPI without parallel imaging. The data collection time was decreased in inverse proportion to the acceleration factor as well. The improved temporal SNR resulted in better statistical power when evaluated on the functional response of the brain. In this study, we demonstrated that the combination of cmsEPI with the parallel imaging technique could provide the improved functional sensitivity for functional imaging study, compensating for the lower SNR by cmsEPI. PMID:26413518

  7. Assessment of regularization techniques for electrocardiographic imaging

    PubMed Central

    Milanič, Matija; Jazbinšek, Vojko; MacLeod, Robert S.; Brooks, Dana H.; Hren, Rok

    2014-01-01

    A widely used approach to solving the inverse problem in electrocardiography involves computing potentials on the epicardium from measured electrocardiograms (ECGs) on the torso surface. The main challenge of solving this electrocardiographic imaging (ECGI) problem lies in its intrinsic ill-posedness. While many regularization techniques have been developed to control wild oscillations of the solution, the choice of proper regularization methods for obtaining clinically acceptable solutions is still a subject of ongoing research. However there has been little rigorous comparison across methods proposed by different groups. This study systematically compared various regularization techniques for solving the ECGI problem under a unified simulation framework, consisting of both 1) progressively more complex idealized source models (from single dipole to triplet of dipoles), and 2) an electrolytic human torso tank containing a live canine heart, with the cardiac source being modeled by potentials measured on a cylindrical cage placed around the heart. We tested 13 different regularization techniques to solve the inverse problem of recovering epicardial potentials, and found that non-quadratic methods (total variation algorithms) and first-order and second-order Tikhonov regularizations outperformed other methodologies and resulted in similar average reconstruction errors. PMID:24369741

  8. The new kid on the block for advanced imaging in Barrett's esophagus: a review of volumetric laser endomicroscopy.

    PubMed

    Trindade, Arvind J; Smith, Michael S; Pleskow, Douglas K

    2016-05-01

    Advanced imaging techniques used in the management of Barrett's esophagus include electronic imaging enhancement (e.g. narrow band imaging, flexible spectral imaging color enhancement, and i-Scan), chromoendoscopy, and confocal laser endomicroscopy. Electronic imaging enhancement is used frequently in daily practice, but use of the other advanced technologies is not routine. High-definition white light endoscopy and random four quadrant biopsy remain the standard of care for evaluation of Barrett's esophagus; this is largely due to the value of advanced imaging technologies not having been validated in large studies or in everyday practice. A new advanced imaging technology called volumetric laser endomicroscopy is commercially available in the United States. Its ease of use and rapid acquisition of high-resolution images make this technology very promising for widespread application. In this article we review the technology and its potential for advanced imaging in Barrett's esophagus. PMID:27134668

  9. The new kid on the block for advanced imaging in Barrett’s esophagus: a review of volumetric laser endomicroscopy

    PubMed Central

    Trindade, Arvind J.; Smith, Michael S.; Pleskow, Douglas K.

    2016-01-01

    Advanced imaging techniques used in the management of Barrett’s esophagus include electronic imaging enhancement (e.g. narrow band imaging, flexible spectral imaging color enhancement, and i-Scan), chromoendoscopy, and confocal laser endomicroscopy. Electronic imaging enhancement is used frequently in daily practice, but use of the other advanced technologies is not routine. High-definition white light endoscopy and random four quadrant biopsy remain the standard of care for evaluation of Barrett’s esophagus; this is largely due to the value of advanced imaging technologies not having been validated in large studies or in everyday practice. A new advanced imaging technology called volumetric laser endomicroscopy is commercially available in the United States. Its ease of use and rapid acquisition of high-resolution images make this technology very promising for widespread application. In this article we review the technology and its potential for advanced imaging in Barrett’s esophagus. PMID:27134668

  10. Integrated Imaging and Vision Techniques for Industrial Inspection: A Special Issue on Machine Vision and Applications

    SciTech Connect

    Liu, Zheng; Ukida, H.; Ramuhalli, Pradeep; Forsyth, D. S.

    2010-06-05

    Imaging- and vision-based techniques play an important role in industrial inspection. The sophistication of the techniques assures high- quality performance of the manufacturing process through precise positioning, online monitoring, and real-time classification. Advanced systems incorporating multiple imaging and/or vision modalities provide robust solutions to complex situations and problems in industrial applications. A diverse range of industries, including aerospace, automotive, electronics, pharmaceutical, biomedical, semiconductor, and food/beverage, etc., have benefited from recent advances in multi-modal imaging, data fusion, and computer vision technologies. Many of the open problems in this context are in the general area of image analysis methodologies (preferably in an automated fashion). This editorial article introduces a special issue of this journal highlighting recent advances and demonstrating the successful applications of integrated imaging and vision technologies in industrial inspection.

  11. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  12. Advancing Techniques of Radiation Therapy for Rectal Cancer.

    PubMed

    Patel, Sagar A; Wo, Jennifer Y; Hong, Theodore S

    2016-07-01

    Since the advent of radiation therapy for rectal cancer, there has been continual investigation of advancing technologies and techniques that allow for improved dose conformality to target structures while limiting irradiation of surrounding normal tissue. For locally advanced disease, intensity modulated and proton beam radiation therapy both provide more highly conformal treatment volumes that reduce dose to organs at risk, though the clinical benefit in terms of toxicity reduction is unclear. For early stage disease, endorectal contact therapy and high-dose rate brachytherapy may be a definitive treatment option for patients who are poor operative candidates or those with low-lying tumors that desire sphincter-preservation. Finally, there has been growing evidence that supports stereotactic body radiotherapy as a safe and effective salvage treatment for the minority of patients that locally recur following trimodality therapy for locally advanced disease. This review addresses these topics that remain areas of active clinical investigation. PMID:27238474

  13. An Advanced Time Averaging Modelling Technique for Power Electronic Circuits

    NASA Astrophysics Data System (ADS)

    Jankuloski, Goce

    For stable and efficient performance of power converters, a good mathematical model is needed. This thesis presents a new modelling technique for DC/DC and DC/AC Pulse Width Modulated (PWM) converters. The new model is more accurate than the existing modelling techniques such as State Space Averaging (SSA) and Discrete Time Modelling. Unlike the SSA model, the new modelling technique, the Advanced Time Averaging Model (ATAM) includes the averaging dynamics of the converter's output. In addition to offering enhanced model accuracy, application of linearization techniques to the ATAM enables the use of conventional linear control design tools. A controller design application demonstrates that a controller designed based on the ATAM outperforms one designed using the ubiquitous SSA model. Unlike the SSA model, ATAM for DC/AC augments the system's dynamics with the dynamics needed for subcycle fundamental contribution (SFC) calculation. This allows for controller design that is based on an exact model.

  14. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  15. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high-quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  16. Techniques calm fear of imaging machine

    SciTech Connect

    Van Pelt, D.

    1990-04-02

    Magnetic resonance imaging has become a valuable tool in diagnosing diseases, and the imaging devices are now used as often as 2 million times a year in the United States. But as many as 10 percent of patients advised to undergo the procedure cannot because they become overwhelmed with claustrophobialike fear triggered by having to lie motionless in the machine's tunnel-like cylinder for about 45 minutes. To counteract this fear, several hospitals now practice various techniques to help reduce the feelings of confinement. One popular method is to give a patient special eyeglasses that allow him to look beyond his feet and see the tunnel opening. Other glasses use mirrors to direct the patient's vision out the back of the unit to large wilderness photographs or murals that simulate a sense of spaciousness. Even a basic item like a set of headphones that plays music can often distract a patient, and technicians frequently hold a patient's hand or foot during the procedure. Another trick is to invite family members and friends to remain with the patient during the scan to provide company and reassurance.

  17. Advance techniques for monitoring human tolerance to positive Gz accelerations

    NASA Technical Reports Server (NTRS)

    Pelligra, R.; Sandler, H.; Rositano, S.; Skrettingland, K.; Mancini, R.

    1973-01-01

    Tolerance to positive g accelerations was measured in ten normal male subjects using both standard and advanced techniques. In addition to routine electrocardiogram, heart rate, respiratory rate, and infrared television, monitoring techniques during acceleration exposure included measurement of peripheral vision loss, noninvasive temporal, brachial, and/or radial arterial blood flow, and automatic measurement of indirect systolic and diastolic blood pressure at 60-sec intervals. Although brachial and radial arterial flow measurements reflected significant cardiovascular changes during and after acceleration, they were inconsistent indices of the onset of grayout or blackout. Temporal arterial blood flow, however, showed a high correlation with subjective peripheral light loss.

  18. Advanced computer graphic techniques for laser range finder (LRF) simulation

    NASA Astrophysics Data System (ADS)

    Bedkowski, Janusz; Jankowski, Stanislaw

    2008-11-01

    This paper show an advanced computer graphic techniques for laser range finder (LRF) simulation. The LRF is the common sensor for unmanned ground vehicle, autonomous mobile robot and security applications. The cost of the measurement system is extremely high, therefore the simulation tool is designed. The simulation gives an opportunity to execute algorithm such as the obstacle avoidance[1], slam for robot localization[2], detection of vegetation and water obstacles in surroundings of the robot chassis[3], LRF measurement in crowd of people[1]. The Axis Aligned Bounding Box (AABB) and alternative technique based on CUDA (NVIDIA Compute Unified Device Architecture) is presented.

  19. Data Compression Techniques for Advanced Space Transportation Systems

    NASA Technical Reports Server (NTRS)

    Bradley, William G.

    1998-01-01

    Advanced space transportation systems, including vehicle state of health systems, will produce large amounts of data which must be stored on board the vehicle and or transmitted to the ground and stored. The cost of storage or transmission of the data could be reduced if the number of bits required to represent the data is reduced by the use of data compression techniques. Most of the work done in this study was rather generic and could apply to many data compression systems, but the first application area to be considered was launch vehicle state of health telemetry systems. Both lossless and lossy compression techniques were considered in this study.

  20. Three-dimensional hybrid grid generation using advancing front techniques

    NASA Technical Reports Server (NTRS)

    Steinbrenner, John P.; Noack, Ralph W.

    1995-01-01

    A new 3-dimensional hybrid grid generation technique has been developed, based on ideas of advancing fronts for both structured and unstructured grids. In this approach, structured grids are first generate independently around individual components of the geometry. Fronts are initialized on these structure grids, and advanced outward so that new cells are extracted directly from the structured grids. Employing typical advancing front techniques, cells are rejected if they intersect the existing front or fail other criteria When no more viable structured cells exist further cells are advanced in an unstructured manner to close off the overall domain, resulting in a grid of 'hybrid' form. There are two primary advantages to the hybrid formulation. First, generating blocks with limited regard to topology eliminates the bottleneck encountered when a multiple block system is used to fully encapsulate a domain. Individual blocks may be generated free of external constraints, which will significantly reduce the generation time. Secondly, grid points near the body (presumably with high aspect ratio) will still maintain a structured (non-triangular or tetrahedral) character, thereby maximizing grid quality and solution accuracy near the surface.

  1. DIFFUSION-WEIGHTED IMAGING OF THE LIVER: TECHNIQUES AND APPLICATIONS

    PubMed Central

    Lewis, Sara; Dyvorne, Hadrien; Cui, Yong; Taouli, Bachir

    2014-01-01

    SYNOPSIS Diffusion weighted MRI (DWI) is a technique that assesses the cellularity, tortuosity of the extracellular/extravascular space and cell membrane density based upon differences in water proton mobility in tissues. The strength of the diffusion weighting is reflected by the b-value. DWI using several b-values enables quantification of the apparent diffusion coefficient (ADC). DWI is increasingly employed in liver imaging for multiple reasons: it can add useful qualitative and quantitative information to conventional imaging sequences, it is acquired relatively quickly, it is easily incorporated into existing clinical protocols, and it is a non-contrast technique. DWI is useful for focal liver lesion detection and characterization, for the assessment of post-treatment tumor response and for evaluation of diffuse liver disease. ADC quantification can be used to characterize lesions as cystic/necrotic or solid and for predicting tumor response to therapy. Advanced diffusion methods such as IVIM (intravoxel incoherent motion) may have potential for detection, staging and evaluation of the progression of liver fibrosis and for liver lesion characterization. The lack of standardization of DWI technique including choice of b-values and sequence parameters has somewhat limited its widespread adoption. PMID:25086935

  2. Rodent models and imaging techniques to study liver regeneration.

    PubMed

    Wei, Weiwei; Dirsch, Olaf; Mclean, Anna Lawson; Zafarnia, Sara; Schwier, Michael; Dahmen, Uta

    2015-01-01

    The liver has the unique capability of regeneration from various injuries. Different animal models and in vitro methods are used for studying the processes and mechanisms of liver regeneration. Animal models were established either by administration of hepatotoxic chemicals or by surgical approach. The administration of hepatotoxic chemicals results in the death of liver cells and in subsequent hepatic regeneration and tissue repair. Surgery includes partial hepatectomy and portal vein occlusion or diversion: hepatectomy leads to compensatory regeneration of the remnant liver lobe, whereas portal vein occlusion leads to atrophy of the ipsilateral lobe and to compensatory regeneration of the contralateral lobe. Adaptation of modern radiological imaging technologies to the small size of rodents made the visualization of rodent intrahepatic vascular anatomy possible. Advanced knowledge of the detailed intrahepatic 3D anatomy enabled the establishment of refined surgical techniques. The same technology allows the visualization of hepatic vascular regeneration. The development of modern histological image analysis tools improved the quantitative assessment of hepatic regeneration. Novel image analysis tools enable us to quantify reliably and reproducibly the proliferative rate of hepatocytes using whole-slide scans, thus reducing the sampling error. In this review, the refined rodent models and the newly developed imaging technology to study liver regeneration are summarized. This summary helps to integrate the current knowledge of liver regeneration and promises an enormous increase in hepatological knowledge in the near future. PMID:25402256

  3. Advanced Imaging Catheter: Final Project Report

    SciTech Connect

    Krulevitch, P; Colston, B; DaSilva, L; Hilken, D; Kluiwstra, J U; Lee, A P; London, R; Miles, R; Schumann, D; Seward, K; Wang, A

    2001-07-20

    Minimally invasive surgery (MIS) is an approach whereby procedures conventionally performed with large and potentially traumatic incisions are replaced by several tiny incisions through which specialized instruments are inserted. Early MIS, often called laparoscopic surgery, used video cameras and laparoscopes to visualize and control the medical devices, which were typically cutting or stapling tools. More recently, catheter-based procedures have become a fast growing sector of all surgeries. In these procedures, small incisions are made into one of the main arteries (e.g. femoral artery in the thigh), and a long thin hollow tube is inserted and positioned near the target area. The key advantage of this technique is that recovery time can be reduced from months to a matter of days. In the United States, over 700,000 catheter procedures are performed annually representing a market of over $350 million. Further growth in this area will require significant improvements in the current catheter technology. In order to effectively navigate a catheter through the tortuous vessels of the body, two capabilities must exist: imaging and positioning. In most cases, catheter procedures rely on radiography for visualization and manual manipulation for positioning of the device. Radiography provides two-dimensional, global images of the vasculature and cannot be used continuously due to radiation exposure to both the patient and physician. Intravascular ultrasound devices are available for continuous local imaging at the catheter tip, but these devices cannot be used simultaneously with therapeutic devices. Catheters are highly compliant devices, and manipulating the catheter is similar to pushing on a string. Often, a guide wire is used to help position the catheter, but this procedure has its own set of problems. Three characteristics are used to describe catheter maneuverability: (1) pushability -- the amount of linear displacement of the distal end (inside body) relative to

  4. Simultaneous algebraic reconstruction technique based on guided image filtering.

    PubMed

    Ji, Dongjiang; Qu, Gangrong; Liu, Baodong

    2016-07-11

    The challenge of computed tomography is to reconstruct high-quality images from few-view projections. Using a prior guidance image, guided image filtering smoothes images while preserving edge features. The prior guidance image can be incorporated into the image reconstruction process to improve image quality. We propose a new simultaneous algebraic reconstruction technique based on guided image filtering. Specifically, the prior guidance image is updated in the image reconstruction process, merging information iteratively. To validate the algorithm practicality and efficiency, experiments were performed with numerical phantom projection data and real projection data. The results demonstrate that the proposed method is effective and efficient for nondestructive testing and rock mechanics. PMID:27410859

  5. Full Endoscopic Spinal Surgery Techniques: Advancements, Indications, and Outcomes

    PubMed Central

    Yue, James J.; Long, William

    2015-01-01

    Advancements in both surgical instrumentation and full endoscopic spine techniques have resulted in positive clinical outcomes in the treatment of cervical, thoracic, and lumbar spine pathologies. Endoscopic techniques impart minimal approach related disruption of non-pathologic spinal anatomy and function while concurrently maximizing functional visualization and correction of pathological tissues. An advanced understanding of the applicable functional neuroanatomy, in particular the neuroforamen, is essential for successful outcomes. Additionally, an understanding of the varying types of disc prolapse pathology in relation to the neuroforamen will result in more optimal surgical outcomes. Indications for lumbar endoscopic spine surgery include disc herniations, spinal stenosis, infections, medial branch rhizotomy, and interbody fusion. Limitations are based on both non spine and spine related findings. A high riding iliac wing, a more posteriorly located retroperitoneal cavity, an overly distal or proximally migrated herniated disc are all relative contra-indications to lumbar endoscopic spinal surgery techniques. Modifications in scope size and visual field of view angulation have enabled both anterior and posterior cervical decompression. Endoscopic burrs, electrocautery, and focused laser technology allow for the least invasive spinal surgical techniques in all age groups and across varying body habitus. Complications include among others, dural tears, dysesthsia, nerve injury, and infection. PMID:26114086

  6. A Review of Significant Advances in Neutron Imaging from Conception to the Present

    NASA Astrophysics Data System (ADS)

    Brenizer, J. S.

    This review summarizes the history of neutron imaging with a focus on the significant events and technical advancements in neutron imaging methods, from the first radiograph to more recent imaging methods. A timeline is presented to illustrate the key accomplishments that advanced the neutron imaging technique. Only three years after the discovery of the neutron by English physicist James Chadwick in 1932, neutron imaging began with the work of Hartmut Kallmann and Ernst Kuhn in Berlin, Germany, from 1935-1944. Kallmann and Kuhn were awarded a joint US Patent issued in January 1940. Little progress was made until the mid-1950's when Thewlis utilized a neutron beam from the BEPO reactor at Harwell, marking the beginning of the application of neutron imaging to practical applications. As the film method was improved, imaging moved from a qualitative to a quantitative technique, with applications in industry and in nuclear fuels. Standards were developed to aid in the quantification of the neutron images and the facility's capabilities. The introduction of dynamic neutron imaging (initially called real-time neutron radiography and neutron television) in the late 1970's opened the door to new opportunities and new challenges. As the electronic imaging matured, the introduction of the CCD imaging devices and solid-state light intensifiers helped address some of these challenges. Development of improved imaging devices for the medical community has had a major impact on neutron imaging. Additionally, amorphous silicon sensors provided improvements in temporal resolution, while providing a reasonably large imaging area. The development of new neutron imaging sensors and the development of new neutron imaging techniques in the past decade has advanced the technique's ability to provide insight and understanding of problems that other non-destructive techniques could not provide. This rapid increase in capability and application would not have been possible without the

  7. A Literature Review on Image Encryption Techniques

    NASA Astrophysics Data System (ADS)

    Khan, Majid; Shah, Tariq

    2014-12-01

    Image encryption plays a paramount part to guarantee classified transmission and capacity of image over web. Then again, a real-time image encryption confronts a more noteworthy test because of vast measure of information included. This paper exhibits an audit on image encryption in spatial, frequency and hybrid domains with both full encryption and selective encryption strategy.

  8. Characterization techniques for semiconductors and nanostructures: a review of recent advances

    NASA Astrophysics Data System (ADS)

    Acher, Olivier

    2015-01-01

    Optical spectroscopy techniques are widely used for the characterization of semiconductors and nanostructures. Confocal Raman microscopy is useful to retrieve chemical and molecular information at the ultimate submicrometer resolution of optical microscopy. Fast imaging capabilities, 3D confocal ability, and multiple excitation wavelengths, have increased the power of the technique while making it simpler to use for material scientists. Recently, the development of the Tip Enhanced Raman Spectroscopy (TERS) has opened the way to the use of Raman information at nanoscale, by combining the resolution of scanning probe microscopy and chemical selectivity of Raman spectroscopy. Significant advances have been reported in the field of profiling the atomic composition of multilayers, using the Glow Discharge Optical Emission Spectroscopy technique, including real-time determination of etched depth by interferometry. This allows the construction of precise atomic profiles of sophisticated multilayers with a few nm resolution. Ellipsometry is another widely used technique to determine the profile of multilayers, and recent development have provided enhanced spatial resolution useful for the investigation of patterned materials. In addition to the advances of the different characterization techniques, the capability to observe the same regions at micrometer scale at different stages of material elaboration, or with different instrument, is becoming a critical issue. Several advances have been made to allow precise re-localization and co-localization of observation with different complementary characterization techniques.

  9. Sharpening advanced land imager multispectral data using a sensor model

    USGS Publications Warehouse

    Lemeshewsky, G.P.

    2005-01-01

    The Advanced Land Imager (ALI) instrument on NASA's Earth Observing One (EO-1) satellite provides for nine spectral bands at 30m ground sample distance (GSD) and a 10m GSD panchromatic band. This report describes an image sharpening technique where the higher spatial resolution information of the panchromatic band is used to increase the spatial resolution of ALI multispectral (MS) data. To preserve the spectral characteristics, this technique combines reported deconvolution deblurring methods for the MS data with highpass filter-based fusion methods for the Pan data. The deblurring process uses the point spread function (PSF) model of the ALI sensor. Information includes calculation of the PSF from pre-launch calibration data. Performance was evaluated using simulated ALI MS data generated by degrading the spatial resolution of high resolution IKONOS satellite MS data. A quantitative measure of performance was the error between sharpened MS data and high resolution reference. This report also compares performance with that of a reported method that includes PSF information. Preliminary results indicate improved sharpening with the method reported here.

  10. Advance of Molecular Imaging Technology and Targeted Imaging Agent in Imaging and Therapy

    PubMed Central

    Chen, Zhi-Yi; Wang, Yi-Xiang; Lin, Yan; Zhang, Jin-Shan; Yang, Feng; Zhou, Qiu-Lan; Liao, Yang-Ying

    2014-01-01

    Molecular imaging is an emerging field that integrates advanced imaging technology with cellular and molecular biology. It can realize noninvasive and real time visualization, measurement of physiological or pathological process in the living organism at the cellular and molecular level, providing an effective method of information acquiring for diagnosis, therapy, and drug development and evaluating treatment of efficacy. Molecular imaging requires high resolution and high sensitive instruments and specific imaging agents that link the imaging signal with molecular event. Recently, the application of new emerging chemical technology and nanotechnology has stimulated the development of imaging agents. Nanoparticles modified with small molecule, peptide, antibody, and aptamer have been extensively applied for preclinical studies. Therapeutic drug or gene is incorporated into nanoparticles to construct multifunctional imaging agents which allow for theranostic applications. In this review, we will discuss the characteristics of molecular imaging, the novel imaging agent including targeted imaging agent and multifunctional imaging agent, as well as cite some examples of their application in molecular imaging and therapy. PMID:24689058

  11. A comparison of conventional and advanced ultrasonic inspection techniques in the characterization of TMC materials

    NASA Astrophysics Data System (ADS)

    Holland, Mark R.; Handley, Scott M.; Miller, James G.; Reighard, Mark K.

    Results obtained with a conventional ultrasonic inspection technique as well as those obtained with more advanced ultrasonic NDE methods in the characterization of an 8-ply quasi-isotropic titanium matrix composite (TMC) specimen are presented. Images obtained from a conventional ultrasonic inspection of TMC material are compared with those obtained using more sophisticated ultrasonic inspection methods. It is suggested that the latter techniques are able to provide quantitative images of TMC material. They are able to reveal the same potential defect indications while simultaneously providing more quantitative information concerning the material's inherent properties. Band-limited signal loss and slope-of-attenuation images provide quantitative data on the inherent material characteristics and defects in TMC.

  12. A comparison of conventional and advanced ultrasonic inspection techniques in the characterization of TMC materials

    NASA Technical Reports Server (NTRS)

    Holland, Mark R.; Handley, Scott M.; Miller, James G.; Reighard, Mark K.

    1992-01-01

    Results obtained with a conventional ultrasonic inspection technique as well as those obtained with more advanced ultrasonic NDE methods in the characterization of an 8-ply quasi-isotropic titanium matrix composite (TMC) specimen are presented. Images obtained from a conventional ultrasonic inspection of TMC material are compared with those obtained using more sophisticated ultrasonic inspection methods. It is suggested that the latter techniques are able to provide quantitative images of TMC material. They are able to reveal the same potential defect indications while simultaneously providing more quantitative information concerning the material's inherent properties. Band-limited signal loss and slope-of-attenuation images provide quantitative data on the inherent material characteristics and defects in TMC.

  13. Advances in ultrasound imaging for congenital malformations during early gestation

    PubMed Central

    Rayburn, William F.; Jolley, Jennifer A.; Simpson, Lynn L.

    2015-01-01

    With refinement in ultrasound technology, detection of fetal structural abnormalities has improved and there have been detailed reports of the natural history and expected outcomes for many anomalies. The ability to either reassure a high-risk woman with normal intrauterine images or offer comprehensive counseling and offer options in cases of strongly suspected lethal or major malformations has shifted prenatal diagnoses to the earliest possible gestational age. When indicated, scans in early gestation are valuable in accurate gestational dating. Stricter sonographic criteria for early nonviability guard against unnecessary intervention. Most birth defects are without known risk factors, and detection of certain malformations is possible in the late first trimester. The best time for a standard complete fetal and placental scan is 18–20 weeks. In addition, certain soft anatomic markers provide clues to chromosomal aneuploidy risk. Maternal obesity and multifetal pregnancies are now more common and further limit early gestation visibility. Other advanced imaging techniques during early gestation in select cases of suspected malformations include fetal echocardiography and magnetic resonance imaging. PMID:25820190

  14. Added Value of Assessing Adnexal Masses with Advanced MRI Techniques

    PubMed Central

    Thomassin-Naggara, I.; Balvay, D.; Rockall, A.; Carette, M. F.; Ballester, M.; Darai, E.; Bazot, M.

    2015-01-01

    This review will present the added value of perfusion and diffusion MR sequences to characterize adnexal masses. These two functional MR techniques are readily available in routine clinical practice. We will describe the acquisition parameters and a method of analysis to optimize their added value compared with conventional images. We will then propose a model of interpretation that combines the anatomical and morphological information from conventional MRI sequences with the functional information provided by perfusion and diffusion weighted sequences. PMID:26413542

  15. Application of image fusion techniques in DSA

    NASA Astrophysics Data System (ADS)

    Ye, Feng; Wu, Jian; Cui, Zhiming; Xu, Jing

    2007-12-01

    Digital subtraction angiography (DSA) is an important technology in both medical diagnoses and interposal therapy, which can eliminate the interferential background and give prominence to blood vessels by computer processing. After contrast material is injected into an artery or vein, a physician produces fluoroscopic images. Using these digitized images, a computer subtracts the image made with contrast material from a series of post injection images made without background information. By analyzing the characteristics of DSA medical images, this paper provides a solution of image fusion which is in allusion to the application of DSA subtraction. We fuse the images of angiogram and subtraction, in order to obtain the new image which has more data information. The image that fused by wavelet transform can display the blood vessels and background information clearly, and medical experts gave high score on the effect of it.

  16. A coming of age: advanced imaging technologies for characterising the developing mouse.

    PubMed

    Norris, Francesca C; Wong, Michael D; Greene, Nicholas D E; Scambler, Peter J; Weaver, Tom; Weninger, Wolfgang J; Mohun, Timothy J; Henkelman, R Mark; Lythgoe, Mark F

    2013-12-01

    The immense challenge of annotating the entire mouse genome has stimulated the development of cutting-edge imaging technologies in a drive for novel information. These techniques promise to improve understanding of the genes involved in embryo development, at least one third of which have been shown to be essential. Aligning advanced imaging technologies with biological needs will be fundamental to maximising the number of phenotypes discovered in the coming years. International efforts are underway to meet this challenge through an integrated and sophisticated approach to embryo phenotyping. We review rapid advances made in the imaging field over the past decade and provide a comprehensive examination of the relative merits of current and emerging techniques. The aim of this review is to provide a guide to state-of-the-art embryo imaging that will enable informed decisions as to which technology to use and fuel conversations between expert imaging laboratories, researchers, and core mouse production facilities. PMID:24035368

  17. A Review of Imaging Techniques for Plant Phenotyping

    PubMed Central

    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

  18. A review of imaging techniques for plant phenotyping.

    PubMed

    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

  19. Advanced computer modeling techniques expand belt conveyor technology

    SciTech Connect

    Alspaugh, M.

    1998-07-01

    Increased mining production is continuing to challenge engineers and manufacturers to keep up. The pressure to produce larger and more versatile equipment is increasing. This paper will show some recent major projects in the belt conveyor industry that have pushed the limits of design and engineering technology. Also, it will discuss the systems engineering discipline and advanced computer modeling tools that have helped make these achievements possible. Several examples of technologically advanced designs will be reviewed. However, new technology can sometimes produce increased problems with equipment availability and reliability if not carefully developed. Computer modeling techniques that help one design larger equipment can also compound operational headaches if engineering processes and algorithms are not carefully analyzed every step of the way.

  20. Advanced aeroservoelastic stabilization techniques for hypersonic flight vehicles

    NASA Technical Reports Server (NTRS)

    Chan, Samuel Y.; Cheng, Peter Y.; Myers, Thomas T.; Klyde, David H.; Magdaleno, Raymond E.; Mcruer, Duane T.

    1992-01-01

    Advanced high performance vehicles, including Single-Stage-To-Orbit (SSTO) hypersonic flight vehicles, that are statically unstable, require higher bandwidth flight control systems to compensate for the instability resulting in interactions between the flight control system, the engine/propulsion dynamics, and the low frequency structural modes. Military specifications, such as MIL-F-9490D and MIL-F-87242, tend to limit treatment of structural modes to conventional gain stabilization techniques. The conventional gain stabilization techniques, however, introduce low frequency effective time delays which can be troublesome from a flying qualities standpoint. These time delays can be alleviated by appropriate blending of gain and phase stabilization techniques (referred to as Hybrid Phase Stabilization or HPS) for the low frequency structural modes. The potential of using HPS for compensating structural mode interaction was previously explored. It was shown that effective time delay was significantly reduced with the use of HPS; however, the HPS design was seen to have greater residual response than a conventional gain stablized design. Additional work performed to advance and refine the HPS design procedure, to further develop residual response metrics as a basis for alternative structural stability specifications, and to develop strategies for validating HPS design and specification concepts in manned simulation is presented. Stabilization design sensitivity to structural uncertainties and aircraft-centered requirements are also assessed.

  1. Development of Backscatter X-Ray Imaging Techniques for Space Vehicle Applications

    NASA Technical Reports Server (NTRS)

    Bartha, Bence B.; Hope, Dale; Vona, Paul; Born, Martin; Corak, Tony

    2009-01-01

    This slide presentation reviews the development of backscatter x ray (BSX) imaging techniques to perform inspection of spacecraft components. The techniques are currently being enhanced to advance Non-Destructive Testing (NDT) methods for future space vehicle applications. The presentation includes an overview of x ray techniques, a description of current BSX applications used on the space shuttle, the development for Constellation applications, and the use of the system for foam applications.

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

    PubMed

    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. PMID:26926991

  3. Three-dimensional region-based adaptive image processing techniques for volume visualization applications

    NASA Astrophysics Data System (ADS)

    de Deus Lopes, Roseli; Zuffo, Marcelo K.; Rangayyan, Rangaraj M.

    1996-04-01

    Recent advances in three-dimensional (3D) imaging techniques have expanded the scope of applications of volume visualization to many areas such as medical imaging, scientific visualization, robotic vision, and virtual reality. Advanced image filtering, enhancement, and analysis techniques are being developed in parallel in the field of digital image processing. Although the fields cited have many aspects in common, it appears that many of the latest developments in image processing are not being applied to the fullest extent possible in visualization. It is common to encounter the use of rather simple and elementary image pre- processing operations being used in visualization and 3D imaging applications. The purpose of this paper is to present an overview of selected topics from recent developments in adaptive image processing and demonstrate or suggest their applications in volume visualization. The techniques include adaptive noise removal; improvement of contrast and visibility of objects; space-variant deblurring and restoration; segmentation-based lossless coding for data compression; and perception-based measures for analysis, enhancement, and rendering. The techniques share the common base of identification of adaptive regions by region growing, which lends them a perceptual basis related to the human visual system. Preliminary results obtained with some of the techniques implemented so far are used to illustrate the concepts involved, and to indicate potential performance capabilities of the methods.

  4. Brain Imaging Techniques and Their Applications in Decision-Making Research

    PubMed Central

    XUE, Gui; CHEN, Chuansheng; LU, Zhong-Lin; DONG, Qi

    2010-01-01

    Advanced noninvasive neuroimaging techniques such as EEG and fMRI allow researchers to directly observe brain activities while subjects perform various perceptual, motor, and/or cognitive tasks. By combining functional brain imaging with sophisticated experimental designs and data analysis methods, functions of brain regions and their interactions can be examined. A nascent field called neuroeconomics has recently emerged as a result of the enormous success of applications of functional brain imaging techniques in the study of human decision-making. In this article, we first provide an overview of brain imaging techniques, focusing on the recent developments in multivariate analysis and multi-modal data integration. We then present several studies on risky decision making, intertemporal choice, and social decision making, to illustrate how neuroimaging techniques can be used to advance our knowledge on decision making. Finally, we discuss challenges and future directions in neuroeconomics. PMID:20376329

  5. New endoscopic imaging techniques in surveillance of inflammatory bowel disease.

    PubMed

    Gabbani, Tommaso; Manetti, Natalia; Bonanomi, Andrea Giovanni; Annese, Antonio Luca; Annese, Vito

    2015-03-16

    Endoscopy plays a crucial role in the management of inflammatory bowel disease (IBD). Advances imaging techniques allow visualization of mucosal details, tissue characteristics and cellular alteration. In particular chromoendoscopy, magnification endoscopy, confocal laser endomicroscopy and endocytoscopy seem to have the possibility to radically modify the approach to surveillance and decision making. Dye-based chromoendoscopy (DBC) and magnification chromoendoscopy improve detection of dysplasia, and evaluation of inflammatory activity and extension of ulcerative colitis and are thus considered the standard of care. Dye-less chromoendoscopy could probably replace conventional DBC for surveillance. Narrow band imaging and i-scan have shown to improve activity and extent assessment in comparison to white-light endoscopy. Confocal laser endomicroscopy (CLE) can detect more dysplastic lesions in surveillance colonoscopy and predict neoplastic and inflammatory changes with high accuracy compared to histology. This technology is best used in conjunction with chromoendoscopy, narrow-band imaging, or autofluorescence because of its minute scanning area. This combination is useful for appropriate tissue classification of mucosal lesions already detected by standard or optically enhanced endoscopy. The best combination for IBD surveillance appear to be chromoendoscopy for identification of areas of suspicion, with further examination with CLE to detect intraepithelial neoplasia. However cost, availability, and experience are still an issue. PMID:25789093

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

    PubMed Central

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

    2011-01-01

    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. PMID:21445356

  7. New endoscopic imaging techniques in surveillance of inflammatory bowel disease

    PubMed Central

    Gabbani, Tommaso; Manetti, Natalia; Bonanomi, Andrea Giovanni; Annese, Antonio Luca; Annese, Vito

    2015-01-01

    Endoscopy plays a crucial role in the management of inflammatory bowel disease (IBD). Advances imaging techniques allow visualization of mucosal details, tissue characteristics and cellular alteration. In particular chromoendoscopy, magnification endoscopy, confocal laser endomicroscopy and endocytoscopy seem to have the possibility to radically modify the approach to surveillance and decision making. Dye-based chromoendoscopy (DBC) and magnification chromoendoscopy improve detection of dysplasia, and evaluation of inflammatory activity and extension of ulcerative colitis and are thus considered the standard of care. Dye-less chromoendoscopy could probably replace conventional DBC for surveillance. Narrow band imaging and i-scan have shown to improve activity and extent assessment in comparison to white-light endoscopy. Confocal laser endomicroscopy (CLE) can detect more dysplastic lesions in surveillance colonoscopy and predict neoplastic and inflammatory changes with high accuracy compared to histology. This technology is best used in conjunction with chromoendoscopy, narrow-band imaging, or autofluorescence because of its minute scanning area. This combination is useful for appropriate tissue classification of mucosal lesions already detected by standard or optically enhanced endoscopy. The best combination for IBD surveillance appear to be chromoendoscopy for identification of areas of suspicion, with further examination with CLE to detect intraepithelial neoplasia. However cost, availability, and experience are still an issue. PMID:25789093

  8. Recent Advances in Imaging Alzheimer’s Disease

    PubMed Central

    Braskie, Meredith N.; Toga, Arthur W.; Thompson, Paul M.

    2014-01-01

    Advances in brain imaging technology in the past five years have contributed greatly to the understanding of Alzheimer’s disease (AD). Here, we review recent research related to amyloid imaging, new methods for magnetic resonance imaging analyses, and statistical methods. We also review research that evaluates AD risk factors and brain imaging, in the context of AD prediction and progression. We selected a variety of illustrative studies, describing how they advanced the field and are leading AD research in promising new directions. PMID:22672880

  9. Testing aspects of advanced coherent electron cooling technique

    SciTech Connect

    Litvinenko, V.; Jing, Y.; Pinayev, I.; Wang, G.; Samulyak, R.; Ratner, D.

    2015-05-03

    An advanced version of the Coherent-electron Cooling (CeC) based on the micro-bunching instability was proposed. This approach promises significant increase in the bandwidth of the CeC system and, therefore, significant shortening of cooling time in high-energy hadron colliders. In this paper we present our plans of simulating and testing the key aspects of this proposed technique using the set-up of the coherent-electron-cooling proof-of-principle experiment at BNL.

  10. [The role of electronic techniques for advanced neuroelectrophysiology].

    PubMed

    Wang, Min; Zhang, Lijun; Cao, Maoyong

    2008-12-01

    The rapid development in the fields of electroscience, computer science, and biomedical engineering are propelling the electrophysiologyical techniques. Recent technological advances have made it possible to simultaneously record the activity of large numbers of neurons in awake and behaving animals using implanted extracellular electrodes. Several laboratories use chronically implanted electrode arrays in freely moving animals because they allow stable recordings of discriminated single neurons and/or field potentials from up to hundreds of electrodes over long time periods. In this review, we focus on the new technologies for neuroelectrophysiology. PMID:19166233

  11. Spectral OCT techniques in eye imaging

    NASA Astrophysics Data System (ADS)

    Kowalczyk, Andrzej; Wojtkowski, Maciej

    2002-02-01

    This contribution presents examples of images of eye in vitro obtained by spectral optical tomography (OCT). Particular interest was focused on obtaining clear images of the corneo-scleral angle and images of fundus which are both essential for diagnosing and planning of a treatment of glaucoma.

  12. New impedance and electrochemical image techniques for biological applications

    NASA Astrophysics Data System (ADS)

    Tao, N. J.

    2010-03-01

    A method to image local surface impedance and electrochemical current optically is developed for biological applications. The principle of the impedance imaging is based on sensitive dependence of surface plasmon resonance (SPR) on local surface charge density. The technique can image local surface impedance and charge while providing simultaneously a conventional surface plasmon resonance (SPR) image. By applying a potential modulation to a sensor surface, it is possible to obtain an image of the DC component, and the amplitude and phase images of the AC component. The DC image provides local molecular binding, as found in the conventional SPR imaging technique. The AC images are directly related to the local impedance of the surface. This imaging capability may be used as a new detection platform for DNA and protein microarrays, a new method for analyzing local molecular binding and interfacial processes and a new tool for imaging cells and tissues.

  13. Functional Imaging and Related Techniques: An Introduction for Rehabilitation Researchers

    PubMed Central

    Crosson, Bruce; Ford, Anastasia; McGregor, Keith M.; Meinzer, Marcus; Cheshkov, Sergey; Li, Xiufeng; Walker-Batson, Delaina; Briggs, Richard W.

    2010-01-01

    Functional neuroimaging and related neuroimaging techniques are becoming important tools for rehabilitation research. Functional neuroimaging techniques can be used to determine the effects of brain injury or disease on brain systems related to cognition and behavior and to determine how rehabilitation changes brain systems. These techniques include: functional magnetic resonance imaging (fMRI), positron emission tomography (PET), electroencephalography (EEG), magnetoencephalography (MEG), near infrared spectroscopy (NIRS), and transcranial magnetic stimulation (TMS). Related diffusion weighted magnetic resonance imaging techniques (DWI), including diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), can quantify white matter integrity. With the proliferation of these imaging techniques in rehabilitation research, it is critical that rehabilitation researchers, as well as consumers of rehabilitation research, become familiar with neuroimaging techniques, what they can offer, and their strengths and weaknesses The purpose to this review is to provide such an introduction to these neuroimaging techniques. PMID:20593321

  14. Tuberculosis, advanced - chest x-rays (image)

    MedlinePlus

    ... tissue, and can cause tissue death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light ... location of cavities within these light areas. The x-ray on the left clearly shows that the opacities ...

  15. Tuberculosis, advanced - chest x-rays (image)

    MedlinePlus

    Tuberculosis is an infectious disease that causes inflammation, the formation of tubercules and other growths within tissue, ... death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light areas (opacities) of varying ...

  16. Imaging techniques in signal transduction IHC.

    PubMed

    Sedgewick, Jerry

    2011-01-01

    Augmentation of digital images is almost always a necessity in order to obtain a reproduction that matches the appearance of the original. However, that augmentation can mislead if it is done incorrectly and not within reasonable limits. When procedures are in place for ensuring that originals are archived, and image manipulation steps are reported, scientists not only follow good laboratory practices, but also avoid ethical issues associated with postprocessing and protect their labs from any future allegations of scientific misconduct. Also, when procedures are in place for correct acquisition of images, the extent of postprocessing is minimized or eliminated. These procedures include color balancing (for brighfield images), keeping tonal values within the dynamic range of the detector, frame averaging to eliminate noise (typically in fluorescence imaging), use of the highest bit depth when a choice is available, flatfield correction, and archiving of the image in a nonlossy format (not JPEG).When postprocessing is necessary, the commonly used applications for correction include Photoshop, and ImageJ, but a free program (GIMP) can also be used. Corrections to images include scaling the bit depth to higher and lower ranges, removing color casts from brightfield images, setting brightness and contrast, reducing color noise, reducing "grainy" noise, conversion of pure colors to grayscale, conversion of grayscale to colors typically used in fluorescence imaging, correction of uneven illumination and flatfield correction, blending color images (fluorescence), and extending the depth of focus. These corrections are explained in step-by-step procedures in the chapter that follows. PMID:21370028

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  19. NEW TECHNIQUES FOR IMAGING AND ANALYZING LUNG TISSUE

    EPA Science Inventory

    The recent technological revolution in the field of imaging techniques has provided pathologists and toxicologists with an expanding repertoire of analytical techniques for studying the interaction between the lung and the various exogenous materials to which it is exposed. Analy...

  20. An image compression technique for use on token ring networks

    NASA Technical Reports Server (NTRS)

    Gorjala, B.; Sayood, Khalid; Meempat, G.

    1992-01-01

    A low complexity technique for compression of images for transmission over local area networks is presented. The technique uses the synchronous traffic as a side channel for improving the performance of an adaptive differential pulse code modulation (ADPCM) based coder.

  1. A Technique for Nanoscale Plasmonic Imaging via Photoemission

    NASA Astrophysics Data System (ADS)

    Pickard, Daniel S.

    2009-03-01

    The scientific community is witnessing increased research activity on Surface Plasmon Polaritons (SPPs). The potential applications of SPPs and plasmonic structures based on their control and manipulation are truly multi-disciplinary, spanning high speed nano-scale interconnects, meta-materials, chemical and biological sensing, sub-wavelength optics and waveguides, near-field optical trapping, high-density data storage, and the enhancement of non-linear effects. Measurement of the localized optical field intensity is a critical component in validating physical models and characterizing plasmonic structures. The dominant technique employed for this task is the Scanning Near-Field Optical Microscope (SNOM) or Photon Scanning Tunneling Microscope (PSTM), whose contrast mechanism is based on measuring light scattered from the near-field with a probe. These techniques can provide high resolution images of the localized fields, but they are slow. Furthermore, tip-sample interactions can perturb the fields, yielding ambiguity between electric and magnetic fields and frustrating attempts at accurate optical characterization. One way to facilitate the advance of plasmonics is to develop new techniques for imaging and characterizing SPP behavior on the nanoscale. Recent efforts employing photoemission to reveal the localized fields have demonstrated that this technique can provide both high spatial (˜10nm) and temporal (fs) resolution when combined with a Photoelectron Emission Microscope (PEEM)[1-3]. The PEEM does not require a probe so the fields can be imaged without perturbation. It also provides a parallel image of the full field, so acquisition times are fast. We are expanding the capabilities of the PEEM to exploit a novel contrast mechanism which will broaden the spectrum of plasmonic devices observable. We present our experimental efforts in this area, detail the underlying physics of the contrast mechanism and discuss how it can be controlled to enable unique

  2. Advanced Imaging Optics Utilizing Wavefront Coding.

    SciTech Connect

    Scrymgeour, David; Boye, Robert; Adelsberger, Kathleen

    2015-06-01

    Image processing offers a potential to simplify an optical system by shifting some of the imaging burden from lenses to the more cost effective electronics. Wavefront coding using a cubic phase plate combined with image processing can extend the system's depth of focus, reducing many of the focus-related aberrations as well as material related chromatic aberrations. However, the optimal design process and physical limitations of wavefront coding systems with respect to first-order optical parameters and noise are not well documented. We examined image quality of simulated and experimental wavefront coded images before and after reconstruction in the presence of noise. Challenges in the implementation of cubic phase in an optical system are discussed. In particular, we found that limitations must be placed on system noise, aperture, field of view and bandwidth to develop a robust wavefront coded system.

  3. Bayesian technique for image classifying registration.

    PubMed

    Hachama, Mohamed; Desolneux, Agnès; Richard, Frédéric J P

    2012-09-01

    In this paper, we address a complex image registration issue arising while the dependencies between intensities of images to be registered are not spatially homogeneous. Such a situation is frequently encountered in medical imaging when a pathology present in one of the images modifies locally intensity dependencies observed on normal tissues. Usual image registration models, which are based on a single global intensity similarity criterion, fail to register such images, as they are blind to local deviations of intensity dependencies. Such a limitation is also encountered in contrast-enhanced images where there exist multiple pixel classes having different properties of contrast agent absorption. In this paper, we propose a new model in which the similarity criterion is adapted locally to images by classification of image intensity dependencies. Defined in a Bayesian framework, the similarity criterion is a mixture of probability distributions describing dependencies on two classes. The model also includes a class map which locates pixels of the two classes and weighs the two mixture components. The registration problem is formulated both as an energy minimization problem and as a maximum a posteriori estimation problem. It is solved using a gradient descent algorithm. In the problem formulation and resolution, the image deformation and the class map are estimated simultaneously, leading to an original combination of registration and classification that we call image classifying registration. Whenever sufficient information about class location is available in applications, the registration can also be performed on its own by fixing a given class map. Finally, we illustrate the interest of our model on two real applications from medical imaging: template-based segmentation of contrast-enhanced images and lesion detection in mammograms. We also conduct an evaluation of our model on simulated medical data and show its ability to take into account spatial variations

  4. Selective document image data compression technique

    DOEpatents

    Fu, Chi-Yung; Petrich, Loren I.

    1998-01-01

    A method of storing information from filled-in form-documents comprises extracting the unique user information in the foreground from the document form information in the background. The contrast of the pixels is enhanced by a gamma correction on an image array, and then the color value of each of pixel is enhanced. The color pixels lying on edges of an image are converted to black and an adjacent pixel is converted to white. The distance between black pixels and other pixels in the array is determined, and a filled-edge array of pixels is created. User information is then converted to a two-color format by creating a first two-color image of the scanned image by converting all pixels darker than a threshold color value to black. All the pixels that are lighter than the threshold color value to white. Then a second two-color image of the filled-edge file is generated by converting all pixels darker than a second threshold value to black and all pixels lighter than the second threshold color value to white. The first two-color image and the second two-color image are then combined and filtered to smooth the edges of the image. The image may be compressed with a unique Huffman coding table for that image. The image file is also decimated to create a decimated-image file which can later be interpolated back to produce a reconstructed image file using a bilinear interpolation kernel.--(235 words)

  5. Selective document image data compression technique

    DOEpatents

    Fu, C.Y.; Petrich, L.I.

    1998-05-19

    A method of storing information from filled-in form-documents comprises extracting the unique user information in the foreground from the document form information in the background. The contrast of the pixels is enhanced by a gamma correction on an image array, and then the color value of each of pixel is enhanced. The color pixels lying on edges of an image are converted to black and an adjacent pixel is converted to white. The distance between black pixels and other pixels in the array is determined, and a filled-edge array of pixels is created. User information is then converted to a two-color format by creating a first two-color image of the scanned image by converting all pixels darker than a threshold color value to black. All the pixels that are lighter than the threshold color value to white. Then a second two-color image of the filled-edge file is generated by converting all pixels darker than a second threshold value to black and all pixels lighter than the second threshold color value to white. The first two-color image and the second two-color image are then combined and filtered to smooth the edges of the image. The image may be compressed with a unique Huffman coding table for that image. The image file is also decimated to create a decimated-image file which can later be interpolated back to produce a reconstructed image file using a bilinear interpolation kernel. 10 figs.

  6. Advances in hyperspectral LWIR pushbroom imagers

    NASA Astrophysics Data System (ADS)

    Holma, Hannu; Mattila, Antti-Jussi; Hyvärinen, Timo; Weatherbee, Oliver

    2011-06-01

    Two long-wave infrared (LWIR) hyperspectral imagers have been under extensive development. The first one utilizes a microbolometer focal plane array (FPA) and the second one is based on an Mercury Cadmium Telluride (MCT) FPA. Both imagers employ a pushbroom imaging spectrograph with a transmission grating and on-axis optics. The main target has been to develop high performance instruments with good image quality and compact size for various industrial and remote sensing application requirements. A big challenge in realizing these goals without considerable cooling of the whole instrument is to control the instrument radiation. The challenge is much bigger in a hyperspectral instrument than in a broadband camera, because the optical signal from the target is spread spectrally, but the instrument radiation is not dispersed. Without any suppression, the instrument radiation can overwhelm the radiation from the target even by 1000 times. The means to handle the instrument radiation in the MCT imager include precise instrument temperature stabilization (but not cooling), efficient optical background suppression and the use of background-monitoring-on-chip (BMC) method. This approach has made possible the implementation of a high performance, extremely compact spectral imager in the 7.7 to 12.4 μm spectral range. The imager performance with 84 spectral bands and 384 spatial pixels has been experimentally verified and an excellent NESR of 14 mW/(m2srμm) at 10 μm wavelength with a 300 K target has been achieved. This results in SNR of more than 700. The LWIR imager based on a microbolometer detector array, first time introduced in 2009, has been upgraded. The sensitivity of the imager has improved drastically by a factor of 3 and SNR by about 15 %. It provides a rugged hyperspectral camera for chemical imaging applications in reflection mode in laboratory and industry.

  7. Surgical techniques for advanced stage pelvic organ prolapse.

    PubMed

    Brown, Douglas N; Strauchon, Christopher; Gonzalez, Hector; Gruber, Daniel

    2016-02-01

    Pelvic organ prolapse is an extremely common condition, with approximately 12% of women requiring surgical correction over their lifetime. This manuscript reviews the most recent literature regarding the comparative efficacy of various surgical repair techniques in the treatment of advanced stage pelvic organ prolapse. Uterosacral ligament suspension has similar anatomic and subjective outcomes when compared to sacrospinous ligament fixation at 12 months and is considered to be equally effective. The use of transvaginal mesh has been shown to be superior to native tissue vaginal repairs with respect to anatomic outcomes but at the cost of a higher complication rate. Minimally invasive sacrocolpopexy appears to be equivalent to abdominal sacrocolpopexy (ASC). Robot-assisted sacrocolpopexy (RSC) and laparoscopic sacrocolpopexy (LSC) appear as effective as abdominal sacrocolpopexy, however, prospective studies of comparing long-term outcomes of ASC, LSC, and RSC in relation to health care costs is paramount in the near future. Surgical correction of advanced pelvic organ prolapse can be accomplished via a variety of proven techniques. Selection of the correct surgical approach is a complex decision process and involves a multitude of factors. When deciding on the most suitable surgical intervention, the chosen route must be individualized for each patient taking into account the specific risks and benefits of each procedure. PMID:26448444

  8. Advanced MRI techniques to improve our understanding of experience-induced neuroplasticity.

    PubMed

    Tardif, Christine Lucas; Gauthier, Claudine Joëlle; Steele, Christopher John; Bazin, Pierre-Louis; Schäfer, Andreas; Schaefer, Alexander; Turner, Robert; Villringer, Arno

    2016-05-01

    Over the last two decades, numerous human MRI studies of neuroplasticity have shown compelling evidence for extensive and rapid experience-induced brain plasticity in vivo. To date, most of these studies have consisted of simply detecting a difference in structural or functional images with little concern for their lack of biological specificity. Recent reviews and public debates have stressed the need for advanced imaging techniques to gain a better understanding of the nature of these differences - characterizing their extent in time and space, their underlying biological and network dynamics. The purpose of this article is to give an overview of advanced imaging techniques for an audience of cognitive neuroscientists that can assist them in the design and interpretation of future MRI studies of neuroplasticity. The review encompasses MRI methods that probe the morphology, microstructure, function, and connectivity of the brain with improved specificity. We underline the possible physiological underpinnings of these techniques and their recent applications within the framework of learning- and experience-induced plasticity in healthy adults. Finally, we discuss the advantages of a multi-modal approach to gain a more nuanced and comprehensive description of the process of learning. PMID:26318050

  9. Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

    2015-04-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

  10. Unified Instrumentation: Examining the Simultaneous Application of Advanced Measurement Techniques for Increased Wind Tunnel Testing Capability

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A. (Editor); Bartram, Scott M.; Humphreys, William M., Jr.; Jenkins, Luther N.; Jordan, Jeffrey D.; Lee, Joseph W.; Leighty, Bradley D.; Meyers, James F.; South, Bruce W.; Cavone, Angelo A.; Ingram, JoAnne L.

    2002-01-01

    A Unified Instrumentation Test examining the combined application of Pressure Sensitive Paint, Projection Moire Interferometry, Digital Particle Image Velocimetry, Doppler Global Velocimetry, and Acoustic Microphone Array has been conducted at the NASA Langley Research Center. The fundamental purposes of conducting the test were to: (a) identify and solve compatibility issues among the techniques that would inhibit their simultaneous application in a wind tunnel, and (b) demonstrate that simultaneous use of advanced instrumentation techniques is feasible for increasing tunnel efficiency and identifying control surface actuation / aerodynamic reaction phenomena. This paper provides summary descriptions of each measurement technique used during the Unified Instrumentation Test, their implementation for testing in a unified fashion, and example results identifying areas of instrument compatibility and incompatibility. Conclusions are drawn regarding the conditions under which the measurement techniques can be operated simultaneously on a non-interference basis. Finally, areas requiring improvement for successfully applying unified instrumentation in future wind tunnel tests are addressed.

  11. Robust image modeling techniques with an image restoration application

    NASA Astrophysics Data System (ADS)

    Kashyap, Rangasami L.; Eom, Kie-Bum

    1988-08-01

    A robust parameter-estimation algorithm for a nonsymmetric half-plane (NSHP) autoregressive model, where the driving noise is a mixture of a Gaussian and an outlier process, is presented. The convergence of the estimation algorithm is proved. An algorithm to estimate parameters and original image intensity simultaneously from the impulse-noise-corrupted image, where the model governing the image is not available, is also presented. The robustness of the parameter estimates is demonstrated by simulation. Finally, an algorithm to restore realistic images is presented. The entire image generally does not obey a simple image model, but a small portion (e.g., 8 x 8) of the image is assumed to obey an NSHP model. The original image is divided into windows and the robust estimation algorithm is applied for each window. The restoration algorithm is tested by comparing it to traditional methods on several different images.

  12. AXIOM: advanced X-ray imaging of the magnetosphere

    NASA Astrophysics Data System (ADS)

    Branduardi-Raymont, Graziella; Sembay, Steve F.; Eastwood, Jonathan P.; Sibeck, David G.; Abbey, Tony A.; Brown, Patrick; Carter, Jenny A.; Carr, Chris M.; Forsyth, Colin; Kataria, Dhiren; Kemble, Steve; Milan, Steve E.; Owen, Chris J.; Peacocke, Lisa; Read, Andy M.; Coates, Andrew J.; Collier, Michael R.; Cowley, Stan W. H.; Fazakerley, Andrew N.; Fraser, George W.; Jones, Geraint H.; Lallement, Rosine; Lester, Mark; Porter, F. Scott; Yeoman, Tim K.

    2012-04-01

    Planetary plasma and magnetic field environments can be studied in two complementary ways—by in situ measurements, or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Some parts of the Earth's magnetosphere have been remotely sensed, but the majority remains unexplored by this type of measurements. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques, which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth's magnetosphere. In this article we describe how an appropriately designed and located X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock, with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth's magnetosphere on a global level. Global images of the dayside magnetospheric boundaries require vantage points well outside the magnetosphere. Our studies have led us to propose `AXIOM: Advanced X-ray Imaging of the Magnetosphere', a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth-Moon L1 point. The model payload consists of an X-ray Wide Field Imager, capable of both imaging and spectroscopy, and an in situ plasma and magnetic field measurement package. This package comprises a Proton-Alpha Sensor, designed to measure the bulk properties of the solar wind, an Ion Composition Analyser, to characterise the minor ion populations in the solar wind that cause charge exchange emission, and a Magnetometer, designed to measure the strength and

  13. AXIOM: Advanced X-ray Imaging of the Magnetosphere

    NASA Technical Reports Server (NTRS)

    Branduardi-Raymont, G.; Sembay, S. F.; Eastwood, J. P.; Sibeck, D. G.; Abbey, A.; Brown, P.; Carter, J. A.; Carr, C. M.; Forsyth, C.; Kataria, D.; Kemble, S.; Milan, S. E.; Owen, C. J.; Peacocke, L.; Read, A. M.; Coates, A. J.; Collier, M. R.; Cowley, S. W. H.; Fazakerley, A. N.; Fraser, G. W.; Jones, G. H.; Lallement, R.; Lester, M.; Porter, F. S.; Yeoman, T. K.

    2012-01-01

    Planetary plasma and magnetic field environments can be studied in two complementary ways - by in situ measurements, or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Some parts of the Earth's magnetosphere have been remotely sensed, but the majority remains unexplored by this type of measurements. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques. which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth's magnetosphere. In this article we describe how an appropriately designed and located. X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock. with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth's magnetosphere on a global level. Global images of the dayside magnetospheric boundaries require vantage points well outside the magnetosphere. Our studies have led us to propose 'AXIOM: Advanced X-ray Imaging Of the Magnetosphere', a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth - Moon Ll point. The model payload consists of an X-ray Wide Field Imager, capable of both imaging and spectroscopy, and an in situ plasma and magnetic field measurement package. This package comprises a Proton-Alpha Sensor, designed to measure the bulk properties of the solar wind, an Ion Composition Analyser, to characterize the minor ion populations in the solar wind that cause charge exchange emission, and a Magnetometer, designed to measure the strength and

  14. AXIOM: Advanced X-Ray Imaging of the Magnetosphere

    NASA Technical Reports Server (NTRS)

    Branduardi-Raymont, G.; Sembay, S. F.; Eastwood, J. P.; Sibeck, D. G.; Abbey, A.; Brown, P.; Carter, J. A.; Carr, C. M.; Forsyth, C.; Kataria, D.; Kemble, S.; Milan, S. E.; Owen, C. J.; Peacocke, L.; Read, A. M.; Coates, A. J.; Collier, M. R.; Cowley, S. W. H.; Fazakerley, A. N.; Fraser, G. W.; Jones, G. H.; Lallement, R.; Lester, M.; Porter, F. S.; Yeoman, T. K.

    2011-01-01

    Planetary plasma and magnetic field environments can be studied in two complementary ways by in situ measurements, or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Some parts of the Earth's magnetosphere have been remotely sensed, but the majority remains unexplored by this type of measurements. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques, which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth's magnetosphere. In this article we describe how an appropriately designed and located X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock, with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth's magnetosphere on a global level. Global images of the dayside magnetospheric boundaries require vantage points well outside the magnetosphere. Our studies have led us to propose AXIOM: Advanced X-ray Imaging Of the Magnetosphere, a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth Moon L1 point. The model payload consists of an X-ray Wide Field Imager, capable of both imaging and spectroscopy, and an in situ plasma and magnetic field measurement package. This package comprises a Proton-Alpha Sensor, designed to measure the bulk properties of the solar wind, an Ion Composition Analyser, to characterize the minor ion populations in the solar wind that cause charge exchange emission, and a Magnetometer, designed to measure the strength and direction

  15. Combining advanced imaging processing and low cost remote imaging capabilities

    NASA Astrophysics Data System (ADS)

    Rohrer, Matthew J.; McQuiddy, Brian

    2008-04-01

    Target images are very important for evaluating the situation when Unattended Ground Sensors (UGS) are deployed. These images add a significant amount of information to determine the difference between hostile and non-hostile activities, the number of targets in an area, the difference between animals and people, the movement dynamics of targets, and when specific activities of interest are taking place. The imaging capabilities of UGS systems need to provide only target activity and not images without targets in the field of view. The current UGS remote imaging systems are not optimized for target processing and are not low cost. McQ describes in this paper an architectural and technologic approach for significantly improving the processing of images to provide target information while reducing the cost of the intelligent remote imaging capability.

  16. A technique for image encryption using digital signature

    NASA Astrophysics Data System (ADS)

    Sinha, Aloka; Singh, Kehar

    2003-04-01

    We propose a new technique to encrypt an image for secure image transmission. The digital signature of the original image is added to the encoded version of the original image. The encoding of the image is done using an appropriate error control code, such as a Bose-Chaudhuri Hochquenghem (BCH) code. At the receiver end, after the decryption of the image, the digital signature can be used to verify the authenticity of the image. Detailed simulations have been carried out to test the encryption technique. An optical correlator, in either the JTC or the VanderLugt geometry, or a digital correlation technique, can be used to verify the authenticity of the decrypted image.

  17. Aortic Stenosis, a Left Ventricular Disease: Insights from Advanced Imaging.

    PubMed

    Badiani, Sveeta; van Zalen, Jet; Treibel, Thomas A; Bhattacharyya, Sanjeev; Moon, James C; Lloyd, Guy

    2016-08-01

    Aortic stenosis (AS) is the most common primary valve disorder in the elderly with an increasing prevalence. It is increasingly clear that it is also a disease of the left ventricle (LV) rather than purely the aortic valve. The transition from left ventricular hypertrophy to fibrosis results in the eventual adverse effects on systolic and diastolic function. Appropriate selection of patients for aortic valve intervention is crucial, and current guidelines recommend aortic valve replacement in severe AS with symptoms or in asymptomatic patients with left ventricular ejection fraction (LVEF) <50 %. LVEF is not a sensitive marker and there are other parameters used in multimodality imaging techniques, including longitudinal strain, exercise stress echo and cardiac MRI that may assist in detecting subclinical and subtle LV dysfunction. These findings offer potentially better ways to evaluate patients, time surgery, predict recovery and potentially offer targets for specific therapies. This article outlines the pathophysiology behind the LV response to aortic stenosis and the role of advanced multimodality imaging in describing it. PMID:27384950

  18. A geometry-based image search engine for advanced RADARSAT-1/2 GIS applications

    NASA Astrophysics Data System (ADS)

    Kotamraju, Vinay; Rabus, Bernhard; Busler, Jennifer

    2012-06-01

    Space-borne Synthetic Aperture Radar (SAR) sensors, such as RADARSAT-1 and -2, enable a multitude of defense and security applications owing to their unique capabilities of cloud penetration, day/night imaging and multi-polarization imaging. As a result, advanced SAR image time series exploitation techniques such as Interferometric SAR (InSAR) and Radargrammetry are now routinely used in applications such as underground tunnel monitoring, infrastructure monitoring and DEM generation. Imaging geometry, as determined by the satellite orbit and imaged terrain, plays a critical role in the success of such techniques. This paper describes the architecture and the current status of development of a geometry-based search engine that allows the search and visualization of archived and future RADARSAT-1 and -2 images appropriate for a variety of advanced SAR techniques and applications. Key features of the search engine's scalable architecture include (a) Interactive GIS-based visualization of the search results; (b) A client-server architecture for online access that produces up-to-date searches of the archive images and that can, in future, be extended to acquisition planning; (c) A techniquespecific search mode, wherein an expert user explicitly sets search parameters to find appropriate images for advanced SAR techniques such as InSAR and Radargrammetry; (d) A future application-specific search mode, wherein all search parameters implicitly default to preset values according to the application of choice such as tunnel monitoring, DEM generation and deformation mapping; (f) Accurate baseline calculations for InSAR searches, and, optimum beam configuration for Radargrammetric searches; (g) Simulated quick look images and technique-specific sensitivity maps in the future.

  19. Advances in Imaging of the Pediatric Pituitary Gland.

    PubMed

    Bou-Ayache, Jad M; Delman, Bradley N

    2016-06-01

    High-resolution MRI of the pediatric sella can help identity or confirm clinical abnormalities, assess pituitary gland size and structure, and reveal acquired lesions. This article reviews contemporary techniques for imaging of the sella and associated structures in this population. Strengths and weaknesses of conventional imaging are discussed, as are techniques that can enhance yield. Some new and emerging technologies are discussed, including MR elastography, perfusion imaging, spectroscopy, and diffusion-weighted and diffusion-tensor imaging. It is expected that this overview will provide insight as to where pediatric sella imaging is currently and where it may head in the future. PMID:27241974

  20. Center for Advanced Signal and Imaging Sciences Workshop 2004

    SciTech Connect

    McClellan, J H; Carrano, C; Poyneer, L; Palmer, D; Baker, K; Chen, D; London, R; Weinert, G; Brase, J; Paglieroni, D; Lopez, A; Grant, C W; Wright, W; Burke, M; Miller, W O; DeTeresa, S; White, D; Toeppen, J; Haugen, P; Kamath, C; Nguyen, T; Manay, S; Newsam, S; Cantu-Paz, E; Pao, H; Chang, J; Chambers, D; Leach, R; Paulson, C; Romero, C E; Spiridon, A; Vigars, M; Welsh, P; Zumstein, J; Romero, K; Oppenheim, A; Harris, D B; Dowla, F; Brown, C G; Clark, G A; Ong, M M; Clance, T J; Kegelmeyer, l M; Benzuijen, M; Bliss, E; Burkhart, S; Conder, A; Daveler, S; Ferguson, W; Glenn, S; Liebman, J; Norton, M; Prasad, R; Salmon, T; Kegelmeyer, L M; Hafiz, O; Cheung, S; Fodor, I; Aufderheide, M B; Bary, A; Martz, Jr., H E; Burke, M W; Benson, S; Fisher, K A; Quarry, M J

    2004-11-15

    Welcome to the Eleventh Annual C.A.S.I.S. Workshop, a yearly event at the Lawrence Livermore National Laboratory, presented by the Center for Advanced Signal & Image Sciences, or CASIS, and sponsored by the LLNL Engineering Directorate. Every November for the last 10 years we have convened a diverse set of engineering and scientific talent to share their work in signal processing, imaging, communications, controls, along with associated fields of mathematics, statistics, and computing sciences. This year is no exception, with sessions in Adaptive Optics, Applied Imaging, Scientific Data Mining, Electromagnetic Image and Signal Processing, Applied Signal Processing, National Ignition Facility (NIF) Imaging, and Nondestructive Characterization.

  1. Recent Advances in Metabolic Profiling And Imaging of Prostate Cancer

    PubMed Central

    Thapar, Roopa; Titus, Mark A

    2015-01-01

    Cancer is a metabolic disease. Cancer cells, being highly proliferative, show significant alterations in metabolic pathways such as glycolysis, respiration, the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, lipid metabolism, and amino acid metabolism. Metabolites like peptides, nucleotides, products of glycolysis, the TCA cycle, fatty acids, and steroids can be an important read out of disease when characterized in biological samples such as tissues and body fluids like urine, serum, etc. The cancer metabolome has been studied since the 1960s by analytical techniques such as mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Current research is focused on the identification and validation of biomarkers in the cancer metabolome that can stratify high-risk patients and distinguish between benign and advanced metastatic forms of the disease. In this review, we discuss the current state of prostate cancer metabolomics, the biomarkers that show promise in distinguishing indolent from aggressive forms of the disease, the strengths and limitations of the analytical techniques being employed, and future applications of metabolomics in diagnostic imaging and personalized medicine of prostate cancer. PMID:25632377

  2. Radiometric calibration of the EO-1 Advanced Land Imager

    NASA Astrophysics Data System (ADS)

    Mendenhall, Jeffrey A.; Lencioni, Donald E.; Parker, Alexander C.

    1999-09-01

    The radiometric calibration of the Earth Observation 1 Advanced Land Imager (EO-1 ALI) was completed in the Spring of 1999 at Lincoln Laboratory. This calibration was conducted with the ALI as a fully assembled instrument in a thermal vacuum chamber at operation temperatures. The ALI was calibrated radiometrically at the system level from 0 to > 100 percent Earth-equivalent albedo using a combination of internal and external halogen and Xenon lamps attached to a large integrating sphere. Absolute radiometric calibration was achieved by measuring the output of the integrating sphere at each radiance level prior to ALI illumination using a NIST-traceable spectroradiometer. Additional radiometric characterization of this instrument was obtained from data collected using a collimator designed for the spectral calibration of the ALI. In this paper we review the techniques employed during radiometric calibration and present the measured gain, linearity, offset, signal-to- noise ratio and polarization sensitivity of each pixel. The testing result of a novel, in-flight solar calibration technique are also discussed. Finally, the results from a Lincoln Laboratory/Goddard Space Flight Center Landsat transfer radiometric study are presented.

  3. Advanced Techniques for Removal of Retrievable Inferior Vena Cava Filters

    SciTech Connect

    Iliescu, Bogdan; Haskal, Ziv J.

    2012-08-15

    Inferior vena cava (IVC) filters have proven valuable for the prevention of primary or recurrent pulmonary embolism in selected patients with or at high risk for venous thromboembolic disease. Their use has become commonplace, and the numbers implanted increase annually. During the last 3 years, in the United States, the percentage of annually placed optional filters, i.e., filters than can remain as permanent filters or potentially be retrieved, has consistently exceeded that of permanent filters. In parallel, the complications of long- or short-term filtration have become increasingly evident to physicians, regulatory agencies, and the public. Most filter removals are uneventful, with a high degree of success. When routine filter-retrieval techniques prove unsuccessful, progressively more advanced tools and skill sets must be used to enhance filter-retrieval success. These techniques should be used with caution to avoid damage to the filter or cava during IVC retrieval. This review describes the complex techniques for filter retrieval, including use of additional snares, guidewires, angioplasty balloons, and mechanical and thermal approaches as well as illustrates their specific application.

  4. Analysis of a proposed Compton backscatter imaging technique

    NASA Astrophysics Data System (ADS)

    Hall, James M.; Jacoby, Barry A.

    1994-03-01

    One-sided imaging techniques are currently being used in nondestructive evaluation of surfaces and shallow subsurface structures. In this work we present both analytical calculations and detailed Monte Carlo simulations aimed at assessing the capability of a proposed Compton backscattering imaging technique designed to detect and characterize voids located several centimeters below the surface of a solid.

  5. Unconventional techniques of fundus imaging: A review.

    PubMed

    Shanmugam, Mahesh P; Mishra, Divyansh Kailash Chandra; Rajesh, R; Madhukumar, R

    2015-07-01

    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. PMID:26458475

  6. Unconventional techniques of fundus imaging: A review

    PubMed Central

    Shanmugam, Mahesh P; Mishra, Divyansh Kailash Chandra; Rajesh, R; Madhukumar, R

    2015-01-01

    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. PMID:26458475

  7. SHG nanoprobes: advancing harmonic imaging in biology.

    PubMed

    Dempsey, William P; Fraser, Scott E; Pantazis, Periklis

    2012-05-01

    Second harmonic generating (SHG) nanoprobes have recently emerged as versatile and durable labels suitable for in vivo imaging, circumventing many of the inherent drawbacks encountered with classical fluorescent probes. Since their nanocrystalline structure lacks a central point of symmetry, they are capable of generating second harmonic signal under intense illumination - converting two photons into one photon of half the incident wavelength - and can be detected by conventional two-photon microscopy. Because the optical signal of SHG nanoprobes is based on scattering, rather than absorption as in the case of fluorescent probes, they neither bleach nor blink, and the signal does not saturate with increasing illumination intensity. When SHG nanoprobes are used to image live tissue, the SHG signal can be detected with little background signal, and they are physiologically inert, showing excellent long-term photostability. Because of their photophysical properties, SHG nanoprobes provide unique advantages for molecular imaging of living cells and tissues with unmatched sensitivity and temporal resolution. PMID:22392481

  8. Advanced terahertz techniques for quality control and counterfeit detection

    NASA Astrophysics Data System (ADS)

    Ahi, Kiarash; Anwar, Mehdi

    2016-04-01

    This paper reports our invented methods for detection of counterfeit electronic. These versatile techniques are also handy in quality control applications. Terahertz pulsed laser systems are capable of giving the material characteristics and thus make it possible to distinguish between the materials used in authentic components and their counterfeit clones. Components with material defects can also be distinguished in section in this manner. In this work different refractive indices and absorption coefficients were observed for counterfeit components compared to their authentic counterparts. Existence of unexpected ingredient materials was detected in counterfeit components by Fourier Transform analysis of the transmitted terahertz pulse. Thicknesses of different layers are obtainable by analyzing the reflected terahertz pulse. Existence of unexpected layers is also detectable in this manner. Recycled, sanded and blacktopped counterfeit electronic components were detected as a result of these analyses. Counterfeit ICs with die dislocations were detected by depicting the terahertz raster scanning data in a coordinate plane which gives terahertz images. In the same manner, raster scanning of the reflected pulse gives terahertz images of the surfaces of the components which were used to investigate contaminant materials and sanded points on the surfaces. The results of the later technique, reveals the recycled counterfeit components.

  9. Advanced MEMS-based infrared imager

    NASA Astrophysics Data System (ADS)

    Chen, Ming

    2003-04-01

    Infrared radiation imager is of important for a wide range of applications. IR infrared imagers have not been widely available due to cost and complexity issues. A major cost of IR imager is associated with the requirements of cooling and pixel-level integration with electronic amplifier and read-out circuitry that are often incompatible with the detector materials. Recent research activities have lead to a new class of IR imager based on thermally isolated MEMS (micro-electromechanical systems) arrays whose bending can be directly detected by optical means. This approach eliminates the need for cooling and complex electronic multiplexers, holding the potential to drastically reduce IR imager cost. However, MEMS based IR imaging devices demonstrated to date are less sensitive than the commercially available ones. We have established a comprehensive finite element model (FEM) using Ansys tool. An accurate computer model for the proposed MEME IR detector is critical for the device development and fabrication. The model greatly enhanced our capability to cost effectively optimize the design from concept to fabrication layout. Our model predicts the deformation of this pixel structure under a surface stress for both thermal and photo-induced effects under various conditions. This simulation model provided a design base for new generation of optical MEMS IR sensors that has higher sensitivity and the potential of incorporating passive thermal amplification. Our simple MEMS design incorporates optical read-out, which eliminates the drawback of electronic means that inevitably introduce additional signal loss due to thermal contact made to the detector element. When packaged under vacuum environment, significant sensitivity improvement is anticipated. The deflection of a cantilever as a function of a rise in its temperature is determined by the classical thermomechanical governing equation for a bimaterial cantilever beam. Our finite element model is established using

  10. Holographic Radar Imaging Privacy Techniques Utilizing Dual-Frequency Implementation

    SciTech Connect

    McMakin, Douglas L.; Hall, Thomas E.; Sheen, David M.

    2008-04-18

    Over the last 15 years, the Pacific Northwest National Laboratory has performed significant research and development activities to enhance the state of the art of holographic radar imaging systems to be used at security checkpoints for screening people for concealed threats hidden under their garments. These enhancement activities included improvements to privacy techniques to remove human features and providing automatic detection of body-worn concealed threats. The enhanced privacy and detection methods used both physical and software imaging techniques. The physical imaging techniques included polarization-diversity illumination and reception, dual-frequency implementation, and high-frequency imaging at 60 GHz. Software imaging techniques to enhance the privacy of the person under surveillance included extracting concealed threat artifacts from the imagery to automatically detect the threat. This paper will focus on physical privacy techniques using dual-frequency implementation.

  11. Imaging radar techniques for remote sensing applications.

    NASA Technical Reports Server (NTRS)

    Zelenka, J. S.

    1972-01-01

    The basic concepts of fine-resolution, imaging radar systems are reviewed. Both side-looking and hologram (downward-looking) radars are described and compared. Several examples of microwave imagery obtained with these two types of systems are shown.

  12. Combined neutron imaging techniques for cultural heritage purpose

    SciTech Connect

    Materna, T.

    2009-01-28

    This article presents the different new neutron techniques developed by the Ancient Charm collaboration to image objects of cultural heritage importance: Prompt-gamma-ray activation imaging (PGAI) coupled to cold/thermal neutron transmission tomography, Neutron Resonance Capture Imaging (NRCI) and Neutron Resonance Tomography.

  13. Three-dimensional imaging techniques: A literature review

    PubMed Central

    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. Advanced Techniques for Power System Identification from Measured Data

    SciTech Connect

    Pierre, John W.; Wies, Richard; Trudnowski, Daniel

    2008-11-25

    Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model to test the performance of the algorithms. University of Wyoming researchers participated in four primary activities: (1) Block and adaptive processing techniques for mode estimation from ambient signals and probing signals, (2) confidence interval estimation, (3) probing signal design and injection method analysis, and (4) performance assessment and validation from simulated and field measured data. Subspace based methods have been use to improve previous results from block processing

  15. COAL AND CHAR STUDIES BY ADVANCED EMR TECHNIQUES

    SciTech Connect

    R. Linn Belford; Robert B. Clarkson; Mark J. Nilges; Boris M. Odintsov; Alex I. Smirnov

    2001-04-30

    Advanced electronic magnetic resonance (EMR) as well as nuclear magnetic resonance (NMR) methods have been used to examine properties of coals, chars, and molecular species related to constituents of coal. During the span of this grant, progress was made on construction and applications to coals and chars of two high frequency EMR systems particularly appropriate for such studies--48 GHz and 95 GHz electron magnetic resonance spectrometer, on new low-frequency dynamic nuclear polarization (DNP) experiments to examine the interaction between water and the surfaces of suspended char particulates in slurries, and on a variety of proton nuclear magnetic resonance (NMR) techniques to measure characteristics of the water directly in contact with the surfaces and pore spaces of carbonaceous particulates.

  16. Techniques for developing approximate optimal advanced launch system guidance

    NASA Technical Reports Server (NTRS)

    Feeley, Timothy S.; Speyer, Jason L.

    1991-01-01

    An extension to the authors' previous technique used to develop a real-time guidance scheme for the Advanced Launch System is presented. The approach is to construct an optimal guidance law based upon an asymptotic expansion associated with small physical parameters, epsilon. The trajectory of a rocket modeled as a point mass is considered with the flight restricted to an equatorial plane while reaching an orbital altitude at orbital injection speeds. The dynamics of this problem can be separated into primary effects due to thrust and gravitational forces, and perturbation effects which include the aerodynamic forces and the remaining inertial forces. An analytic solution to the reduced-order problem represented by the primary dynamics is possible. The Hamilton-Jacobi-Bellman or dynamic programming equation is expanded in an asymptotic series where the zeroth-order term (epsilon = 0) can be obtained in closed form.

  17. Technique for identifying, tracing, or tracking objects in image data

    DOEpatents

    Anderson, Robert J.; Rothganger, Fredrick

    2012-08-28

    A technique for computer vision uses a polygon contour to trace an object. The technique includes rendering a polygon contour superimposed over a first frame of image data. The polygon contour is iteratively refined to more accurately trace the object within the first frame after each iteration. The refinement includes computing image energies along lengths of contour lines of the polygon contour and adjusting positions of the contour lines based at least in part on the image energies.

  18. Advances in Lymphatic Imaging and Drug Delivery

    SciTech Connect

    Nune, Satish K.; Gunda, Padmaja; Majeti, Bharat K.; Thallapally, Praveen K.; Laird, Forrest M.

    2011-09-10

    Cancer remains the second leading cause of death after heart disease in the US. While metastasized cancers such as breast, prostate, and colon are incurable, before their distant spread, these diseases will have invaded the lymphatic system as a first step in their progression. Hence, proper evaluation of the disease state of the lymphatics which drain a tumor site is crucial to staging and the formation of a treatment plan. Current lymphatic imaging modalities with visible dyes and radionucleotide tracers offer limited sensitivity and poor resolution; however, newer tools using nanocarriers, quantum dots, and magnetic resonance imaging promise to vastly improve the staging of lymphatic spread without needless biopsies. Concurrent with the improvement of lymphatic imaging agents, has been the development of drug carriers that can localize chemotherapy to the lymphatic system, thus improving the treatment of localized disease while minimizing the exposure of healthy organs to cytotoxic drugs. This review will focus on polymeric systems that have been developed for imaging and drug delivery to the lymph system, how these new devices improve upon current technologies, and where further improvement is needed.

  19. Image processing technique based on image understanding architecture

    NASA Astrophysics Data System (ADS)

    Kuvychko, Igor

    2000-12-01

    Effectiveness of image applications is directly based on its abilities to resolve ambiguity and uncertainty in the real images. That requires tight integration of low-level image processing with high-level knowledge-based reasoning, which is the solution of the image understanding problem. This article presents a generic computational framework necessary for the solution of image understanding problem -- Spatial Turing Machine. Instead of tape of symbols, it works with hierarchical networks dually represented as discrete and continuous structures. Dual representation provides natural transformation of the continuous image information into the discrete structures, making it available for analysis. Such structures are data and algorithms at the same time and able to perform graph and diagrammatic operations being the basis of intelligence. They can create derivative structures that play role of context, or 'measurement device,' giving the ability to analyze, and run top-bottom algorithms. Symbols naturally emerge there, and symbolic operations work in combination with new simplified methods of computational intelligence. That makes images and scenes self-describing, and provides flexible ways of resolving uncertainty. Classification of images truly invariant to any transformation could be done via matching their derivative structures. New proposed architecture does not require supercomputers, opening ways to the new image technologies.

  20. Advanced MRI Techniques in the Evaluation of Complex Cystic Breast Lesions

    PubMed Central

    Popli, Manju Bala; Gupta, Pranav; Arse, Devraj; Kumar, Pawan; Kaur, Prabhjot

    2016-01-01

    OBJECTIVE The purpose of this research work was to evaluate complex cystic breast lesions by advanced MRI techniques and correlating imaging with histologic findings. METHODS AND MATERIALS In a cross-sectional design from September 2013 to August 2015, 50 patients having sonographically detected complex cystic lesions of the breast were included in the study. Morphological characteristics were assessed. Dynamic contrast-enhanced MRI along with diffusion-weighted imaging and MR spectroscopy were used to further classify lesions into benign and malignant categories. All the findings were correlated with histopathology. RESULTS Of the 50 complex cystic lesions, 32 proved to be benign and 18 were malignant on histopathology. MRI features of heterogeneous enhancement on CE-MRI (13/18), Type III kinetic curve (13/18), reduced apparent diffusion coefficient (18/18), and tall choline peak (17/18) were strong predictors of malignancy. Thirteen of the 18 lesions showed a combination of Type III curve, reduced apparent diffusion coefficient value, and tall choline peak. CONCLUSIONS Advanced MRI techniques like dynamic imaging, diffusion-weighted sequences, and MR spectroscopy provide a high level of diagnostic confidence in the characterization of complex cystic breast lesion, thus allowing early diagnosis and significantly reducing patient morbidity and mortality. From our study, lesions showing heterogeneous contrast enhancement, Type III kinetic curve, diffusion restriction, and tall choline peak were significantly associated with malignant complex cystic lesions of the breast. PMID:27330299

  1. Real-time optical image processing techniques

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang

    1988-01-01

    Nonlinear real-time optical processing on spatial pulse frequency modulation has been pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the modification of micro-channel spatial light modulators (MSLMs). Micro-channel spatial light modulators are modified via the Fabry-Perot method to achieve the high gamma operation required for non-linear operation. Real-time nonlinear processing was performed using the halftone screen and MSLM. The experiments showed the effectiveness of the thresholding and also showed the needs of higher SBP for image processing. The Hughes LCLV has been characterized and found to yield high gamma (about 1.7) when operated in low frequency and low bias mode. Cascading of two LCLVs should also provide enough gamma for nonlinear processing. In this case, the SBP of the LCLV is sufficient but the uniformity of the LCLV needs improvement. These include image correlation, computer generation of holograms, pseudo-color image encoding for image enhancement, and associative-retrieval in neural processing. The discovery of the only known optical method for dynamic range compression of an input image in real-time by using GaAs photorefractive crystals is reported. Finally, a new architecture for non-linear multiple sensory, neural processing has been suggested.

  2. Scintigraphic techniques for hepatic imaging. Update for 2000.

    PubMed

    Drane, W E

    1998-03-01

    Nuclear medicine continues to evolve from a generic imaging approach to a collection of imaging techniques that are disease-specific. In-111 octreotide SPECT scan has quickly become the method of choice to image gastrinoma. A number of other agents have a role in other tumor models. FDG imaging of the liver is in its infancy, but has potential to outperform anatomic methods (CT scan, MR imaging), particularly in the detection of colorectal cancer metastases. The imaging of FDG in nuclear medicine involves rapidly evolving technology and has the potential to diffuse to the community level practice. To further face the controversial areas head on, another problem for nuclear medicine's role in hepatic imaging remains its somewhat separate existence from radiology. Frequently, the abdominal imager or the general radiologist is in the best position to recommend a scintigraphic liver study. A broad knowledge of these techniques by all radiologists is essential for their ultimate success. PMID:9520984

  3. Applications of Advanced Nondestructive Measurement Techniques to Address Safety of Flight Issues on NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Prosser, Bill

    2016-01-01

    Advanced nondestructive measurement techniques are critical for ensuring the reliability and safety of NASA spacecraft. Techniques such as infrared thermography, THz imaging, X-ray computed tomography and backscatter X-ray are used to detect indications of damage in spacecraft components and structures. Additionally, sensor and measurement systems are integrated into spacecraft to provide structural health monitoring to detect damaging events that occur during flight such as debris impacts during launch and assent or from micrometeoroid and orbital debris, or excessive loading due to anomalous flight conditions. A number of examples will be provided of how these nondestructive measurement techniques have been applied to resolve safety critical inspection concerns for the Space Shuttle, International Space Station (ISS), and a variety of launch vehicles and unmanned spacecraft.

  4. Externally triggered imaging technique for microbolometer-type terahertz imager

    NASA Astrophysics Data System (ADS)

    Oda, Naoki; Sudou, Takayuki; Ishi, Tsutomu; Okubo, Syuichi; Isoyama, Goro; Irizawa, Akinori; Kawase, Keigo; Kato, Ryukou

    2016-04-01

    The authors developed terahertz (THz) imager which incorporates 320x240 focal plane array (FPA) with enhanced sensitivity in sub-THz region (ca. 0.5 THz). The imager includes functions such as external-trigger imaging, lock-in imaging, beam profiling and so on. The function of the external-trigger imaging is mainly described in this paper, which was verified in combination of the THz imager with the pulsed THz free electron laser (THz-FEL) developed by Osaka University. The THz-FEL emits THz radiation in a wavelength range of 25 - 150 μm at repetition rates of 2.5, 3.3, 5.0 and 10 pulses per second. The external trigger pulse for the THz imager was generated with a pulse generator, using brightening pulse for THz-FEL. A series of pulses emitted by the THz-FEL at 86 μm were introduced to the THz imager and Joule meter via beam splitter, so that the output signal of THz imager was normalized with the output of the Joule meter and the stability of the THz radiation from FEL was also monitored. The normalized output signals of THz imager (digits/μJ) obtained at the repetition rates mentioned above were found consistent with one another. The timing-relation of the external trigger pulse to the brightening pulse was varied and the influence of the timing-relation on beam pattern is presented. These experimental results verify that the external trigger imaging function operates correctly.

  5. Infrared Imaging Data Reduction Software and Techniques

    NASA Astrophysics Data System (ADS)

    Sabbey, C. N.; McMahon, R. G.; Lewis, J. R.; Irwin, M. J.

    Developed to satisfy certain design requirements not met in existing packages (e.g., full weight map handling) and to optimize the software for large data sets (non-interactive tasks that are CPU and disk efficient), the InfraRed Data Reduction software package is a small ANSI C library of fast image processing routines for automated pipeline reduction of infrared (dithered) observations. The software includes stand-alone C programs for tasks such as running sky frame subtraction with object masking, image registration and co-addition with weight maps, dither offset measurement using cross-correlation, and object mask dilation. Although currently used for near-IR mosaic images, the modular software is concise and readily adaptable for reuse in other work. IRDR, available via anonymous ftp at ftp.ast.cam.ac.uk in pub/sabbey

  6. Quantitative Phase Imaging Techniques for the Study of Cell Pathophysiology: From Principles to Applications

    PubMed Central

    Lee, KyeoReh; Kim, Kyoohyun; Jung, Jaehwang; Heo, JiHan; Cho, Sangyeon; Lee, Sangyun; Chang, Gyuyoung; Jo, YoungJu; Park, Hyunjoo; Park, YongKeun

    2013-01-01

    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. PMID:23539026

  7. INVITED REVIEW-IMAGE REGISTRATION IN VETERINARY RADIATION ONCOLOGY: INDICATIONS, IMPLICATIONS, AND FUTURE ADVANCES.

    PubMed

    Feng, Yang; Lawrence, Jessica; Cheng, Kun; Montgomery, Dean; Forrest, Lisa; Mclaren, Duncan B; McLaughlin, Stephen; Argyle, David J; Nailon, William H

    2016-03-01

    The field of veterinary radiation therapy (RT) has gained substantial momentum in recent decades with significant advances in conformal treatment planning, image-guided radiation therapy (IGRT), and intensity-modulated (IMRT) techniques. At the root of these advancements lie improvements in tumor imaging, image alignment (registration), target volume delineation, and identification of critical structures. Image registration has been widely used to combine information from multimodality images such as computerized tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) to improve the accuracy of radiation delivery and reliably identify tumor-bearing areas. Many different techniques have been applied in image registration. This review provides an overview of medical image registration in RT and its applications in veterinary oncology. A summary of the most commonly used approaches in human and veterinary medicine is presented along with their current use in IGRT and adaptive radiation therapy (ART). It is important to realize that registration does not guarantee that target volumes, such as the gross tumor volume (GTV), are correctly identified on the image being registered, as limitations unique to registration algorithms exist. Research involving novel registration frameworks for automatic segmentation of tumor volumes is ongoing and comparative oncology programs offer a unique opportunity to test the efficacy of proposed algorithms. PMID:26777133

  8. Modulation transfer function measurement technique for image sensor arrays

    NASA Astrophysics Data System (ADS)

    Jin, Hui; Jiang, Huilin; Zhang, XiaoHui

    2010-08-01

    A new technique is demonstrated for measurement of modulation transfer function (MTF) on image sensor arrays. Fourier analysis of a low frequency bar target pattern is used to extract MTF at odd harmonics of a target pattern frequency up to and beyond Nyquist. The technique is particularly useful for linear image arrays (either conventional linescan or time-delay- integration devices) where conventional slanted-edge technique is not always applicable. The technique is well suited to simple implementation and can provide live presentation of the MTF curve, which helps to ensure optimal alignment conditions are achieved. Detailed analysis of the technique and demonstration of experimental results are presented.

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

    SciTech Connect

    Abi-Jaoudeh, Nadine; Kruecker, Jochen; Kadoury, Samuel; Kobeiter, Hicham; Venkatesan, Aradhana M. Levy, Elliot Wood, Bradford J.

    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.

  10. Advanced Imaging Among Health Maintenance Organization Enrollees With Cancer

    PubMed Central

    Loggers, Elizabeth T.; Fishman, Paul A.; Peterson, Do; O'Keeffe-Rosetti, Maureen; Greenberg, Caprice; Hornbrook, Mark C.; Kushi, Lawrence H.; Lowry, Sarah; Ramaprasan, Arvind; Wagner, Edward H.; Weeks, Jane C.; Ritzwoller, Debra P.

    2014-01-01

    Purpose: Fee-for-service (FFS) Medicare expenditures for advanced imaging studies (defined as computed tomography [CT], magnetic resonance imaging [MRI], positron emission tomography [PET] scans, and nuclear medicine studies [NM]) rapidly increased in the past two decades for patients with cancer. Imaging rates are unknown for patients with cancer, whether under or over age 65 years, in health maintenance organizations (HMOs), where incentives may differ. Materials and Methods: Incident cases of breast, colorectal, lung, prostate, leukemia, and non-Hodgkin lymphoma (NHL) cancers diagnosed in 2003 and 2006 from four HMOs in the Cancer Research Network were used to determine 2-year overall mean imaging counts and average total imaging costs per HMO enrollee by cancer type for those under and over age 65. Results: There were 44,446 incident cancer patient cases, with a median age of 75 (interquartile range, 71-81), and 454,029 imaging procedures were performed. The mean number of images per patient increased from 7.4 in 2003 to 12.9 in 2006. Rates of imaging were similar across age groups, with the exception of greater use of echocardiograms and NM studies in younger patients with breast cancer and greater use of PET among younger patients with lung cancer. Advanced imaging accounted for approximately 41% of all imaging, or approximately 85% of the $8.7 million in imaging expenditures. Costs were nearly $2,000 per HMO enrollee; costs for younger patients with NHL, leukemia, and lung cancer were nearly $1,000 more in 2003. Conclusion: Rates of advanced imaging appear comparable among FFS and HMO participants of any age with these six cancers. PMID:24844241

  11. Advancements in MR imaging of the prostate: from diagnosis to interventions.

    PubMed

    Bonekamp, David; Jacobs, Michael A; El-Khouli, Riham; Stoianovici, Dan; Macura, Katarzyna J

    2011-01-01

    Prostate cancer is the most frequently diagnosed cancer in males and the second leading cause of cancer-related death in men. Assessment of prostate cancer can be divided into detection, localization, and staging; accurate assessment is a prerequisite for optimal clinical management and therapy selection. Magnetic resonance (MR) imaging has been shown to be of particular help in localization and staging of prostate cancer. Traditional prostate MR imaging has been based on morphologic imaging with standard T1-weighted and T2-weighted sequences, which has limited accuracy. Recent advances include additional functional and physiologic MR imaging techniques (diffusion-weighted imaging, MR spectroscopy, and perfusion imaging), which allow extension of the obtainable information beyond anatomic assessment. Multiparametric MR imaging provides the highest accuracy in diagnosis and staging of prostate cancer. In addition, improvements in MR imaging hardware and software (3-T vs 1.5-T imaging) continue to improve spatial and temporal resolution and the signal-to-noise ratio of MR imaging examinations. Another recent advancement in the field is MR imaging guidance for targeted prostate biopsy, which is an alternative to the current standard of transrectal ultrasonography-guided systematic biopsy. PMID:21571651

  12. Technique for improving solid state mosaic images

    NASA Technical Reports Server (NTRS)

    Saboe, J. M.

    1969-01-01

    Method identifies and corrects mosaic image faults in solid state visual displays and opto-electronic presentation systems. Composite video signals containing faults due to defective sensing elements are corrected by a memory unit that contains the stored fault pattern and supplies the appropriate fault word to the blanking circuit.

  13. Towards Automatic Image Segmentation Using Optimised Region Growing Technique

    NASA Astrophysics Data System (ADS)

    Alazab, Mamoun; Islam, Mofakharul; Venkatraman, Sitalakshmi

    Image analysis is being adopted extensively in many applications such as digital forensics, medical treatment, industrial inspection, etc. primarily for diagnostic purposes. Hence, there is a growing interest among researches in developing new segmentation techniques to aid the diagnosis process. Manual segmentation of images is labour intensive, extremely time consuming and prone to human errors and hence an automated real-time technique is warranted in such applications. There is no universally applicable automated segmentation technique that will work for all images as the image segmentation is quite complex and unique depending upon the domain application. Hence, to fill the gap, this paper presents an efficient segmentation algorithm that can segment a digital image of interest into a more meaningful arrangement of regions and objects. Our algorithm combines region growing approach with optimised elimination of false boundaries to arrive at more meaningful segments automatically. We demonstrate this using X-ray teeth images that were taken for real-life dental diagnosis.

  14. Advanced Ecosystem Mapping Techniques for Large Arctic Study Domains Using Calibrated High-Resolution Imagery

    NASA Astrophysics Data System (ADS)

    Macander, M. J.; Frost, G. V., Jr.

    2015-12-01

    Regional-scale mapping of vegetation and other ecosystem properties has traditionally relied on medium-resolution remote sensing such as Landsat (30 m) and MODIS (250 m). Yet, the burgeoning availability of high-resolution (<=2 m) imagery and ongoing advances in computing power and analysis tools raises the prospect of performing ecosystem mapping at fine spatial scales over large study domains. Here we demonstrate cutting-edge mapping approaches over a ~35,000 km² study area on Alaska's North Slope using calibrated and atmospherically-corrected mosaics of high-resolution WorldView-2 and GeoEye-1 imagery: (1) an a priori spectral approach incorporating the Satellite Imagery Automatic Mapper (SIAM) algorithms; (2) image segmentation techniques; and (3) texture metrics. The SIAM spectral approach classifies radiometrically-calibrated imagery to general vegetation density categories and non-vegetated classes. The SIAM classes were developed globally and their applicability in arctic tundra environments has not been previously evaluated. Image segmentation, or object-based image analysis, automatically partitions high-resolution imagery into homogeneous image regions that can then be analyzed based on spectral, textural, and contextual information. We applied eCognition software to delineate waterbodies and vegetation classes, in combination with other techniques. Texture metrics were evaluated to determine the feasibility of using high-resolution imagery to algorithmically characterize periglacial surface forms (e.g., ice-wedge polygons), which are an important physical characteristic of permafrost-dominated regions but which cannot be distinguished by medium-resolution remote sensing. These advanced mapping techniques provide products which can provide essential information supporting a broad range of ecosystem science and land-use planning applications in northern Alaska and elsewhere in the circumpolar Arctic.

  15. Dyslexia: advances in clinical and imaging studies.

    PubMed

    Koeda, Tatsuya; Seki, Ayumi; Uchiyama, Hitoshi; Sadato, Norihiro

    2011-03-01

    The aim of this report is to describe the characteristics of Japanese dyslexia, and to demonstrate several of our studies about the extraction of these characteristic and their neurophysiological and neuroimaging abnormalities, as well as advanced studies of phonological awareness and the underlying neural substrate. Based on these results, we have proposed a 2-step approach for remedial education (e-learning web site: http://www.dyslexia-koeda.jp/). The first step is decoding, which decreases reading errors, and the second is vocabulary learning, which improves reading fluency. This 2-step approach is designed to serve first grade children. In addition, we propose the RTI (response to intervention) model as a desirable system for remedial education. PMID:21146943

  16. Cylindrical millimeter-wave imaging technique and applications

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2006-05-01

    The wideband microwave or millimeter-wave cylindrical imaging technique has been developed at Pacific Northwest National Laboratory (PNNL) for several applications including concealed weapon detection and automated body measurement for apparel fitting. This technique forms a fully-focused, diffraction-limited, three-dimensional image of the person or imaging target by scanning an inward-directed vertical array around the person or imaging target. The array is switched electronically to sequence across the array at high-speed, so that a full 360 degree mechanical scan over the cylindrical aperture can occur in 2-10 seconds. Wideband, coherent reflection data from each antenna position are recorded in a computer and subsequently reconstructed using an FFT-based image reconstruction algorithm developed at PNNL. The cylindrical scanning configuration is designed to optimize the illumination of the target and minimize non-returns due to specular reflection of the illumination away from the array. In this paper, simulated modeling data are used to explore imaging issues that affect the cylindrical imaging technique. Physical optics scattering simulations are used to model realistic returns from curved surfaces to determine the extent to which specular reflection affects the signal return and subsequent image reconstruction from these surfaces. This is a particularly important issue for the body measurement application. Also, an artifact in the imaging technique, referred to as "circular convolution aliasing" is discussed including methods to reduce or eliminate it. Numerous simulated and laboratory measured imaging results are presented.

  17. On Advanced Estimation Techniques for Exoplanet Detection and Characterization Using Ground-based Coronagraphs

    PubMed Central

    Lawson, Peter R.; Poyneer, Lisa; Barrett, Harrison; Frazin, Richard; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; Gładysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jérôme; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Pearson, Iain; Perrin, Marshall; Pueyo, Laurent; Savransky, Dmitry

    2015-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012. PMID:26347393

  18. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-based Coronagraphs

    NASA Technical Reports Server (NTRS)

    Lawson, Peter; Frazin, Richard

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012

  19. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-Based Coronagraphs

    NASA Technical Reports Server (NTRS)

    Lawson, Peter R.; Frazin, Richard; Barrett, Harrison; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; Gladysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jerome; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Perrin, Marshall; Poyneer, Lisa; Pueyo, Laurent; Savransky, Dmitry; Soummer, Remi

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We provide a formal comparison of techniques through a blind data challenge and evaluate performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012.

  20. Advances in CT imaging for urolithiasis

    PubMed Central

    Andrabi, Yasir; Patino, Manuel; Das, Chandan J.; Eisner, Brian; Sahani, Dushyant V.; Kambadakone, Avinash

    2015-01-01

    Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime-estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow-up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT) is highly sensitive (>95%) and specific (>96%) in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi-detector CT (MDCT) and technological innovations in CT such as dual-energy CT (DECT) has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre-treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT-related radiation dose exposure remains a valid concern, the use of low-dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post-treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice. PMID:26166961

  1. Satisfaction of search experiments in advanced imaging

    NASA Astrophysics Data System (ADS)

    Berbaum, Kevin S.

    2012-03-01

    The objective of our research is to understand the perception of multiple abnormalities in an imaging examination and to develop strategies for improved diagnostic. We are one of the few laboratories in the world pursuing the goal of reducing detection errors through a better understanding of the underlying perceptual processes involved. Failure to detect an abnormality is the most common class of error in diagnostic imaging and generally is considered the most serious by the medical community. Many of these errors have been attributed to "satisfaction of search," which occurs when a lesion is not reported because discovery of another abnormality has "satisfied" the goal of the search. We have gained some understanding of the mechanisms of satisfaction of search (SOS) traditional radiographic modalities. Currently, there are few interventions to remedy SOS error. For example, patient history that the prompts specific abnormalities, protects the radiologist from missing them even when other abnormalities are present. The knowledge gained from this programmatic research will lead to reduction of observer error.

  2. Advances in CT imaging for urolithiasis.

    PubMed

    Andrabi, Yasir; Patino, Manuel; Das, Chandan J; Eisner, Brian; Sahani, Dushyant V; Kambadakone, Avinash

    2015-01-01

    Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime-estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow-up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT) is highly sensitive (>95%) and specific (>96%) in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi-detector CT (MDCT) and technological innovations in CT such as dual-energy CT (DECT) has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre-treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT-related radiation dose exposure remains a valid concern, the use of low-dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post-treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice. PMID:26166961

  3. Advanced terahertz imaging system performance model for concealed weapon identification

    NASA Astrophysics Data System (ADS)

    Murrill, Steven R.; Redman, Brian; Espinola, Richard L.; Franck, Charmaine C.; Petkie, Douglas T.; De Lucia, Frank C.; Jacobs, Eddie L.; Griffin, Steven T.; Halford, Carl E.; Reynolds, Joe

    2007-04-01

    The U.S. Army Night Vision and Electronic Sensors Directorate (NVESD) and the U.S. Army Research Laboratory (ARL) have developed a terahertz-band imaging system performance model for detection and identification of concealed weaponry. The details of this MATLAB-based model which accounts for the effects of all critical sensor and display components, and for the effects of atmospheric attenuation, concealment material attenuation, and active illumination, were reported on at the 2005 SPIE Europe Security and Defence Symposium. The focus of this paper is to report on recent advances to the base model which have been designed to more realistically account for the dramatic impact that target and background orientation can have on target observability as related to specular and Lambertian reflections captured by an active-illumination-based imaging system. The advanced terahertz-band imaging system performance model now also accounts for target and background thermal emission, and has been recast into a user-friendly, Windows-executable tool. This advanced THz model has been developed in support of the Defense Advanced Research Project Agency's (DARPA) Terahertz Imaging Focal-Plane Technology (TIFT) program. This paper will describe the advanced THz model and its new radiometric sub-model in detail, and provide modeling and experimental results on target observability as a function of target and background orientation.

  4. MO-C-18A-01: Advances in Model-Based 3D Image Reconstruction

    SciTech Connect

    Chen, G; Pan, X; Stayman, J; Samei, E

    2014-06-15

    Recent years have seen the emergence of CT image reconstruction techniques that exploit physical models of the imaging system, photon statistics, and even the patient to achieve improved 3D image quality and/or reduction of radiation dose. With numerous advantages in comparison to conventional 3D filtered backprojection, such techniques bring a variety of challenges as well, including: a demanding computational load associated with sophisticated forward models and iterative optimization methods; nonlinearity and nonstationarity in image quality characteristics; a complex dependency on multiple free parameters; and the need to understand how best to incorporate prior information (including patient-specific prior images) within the reconstruction process. The advantages, however, are even greater – for example: improved image quality; reduced dose; robustness to noise and artifacts; task-specific reconstruction protocols; suitability to novel CT imaging platforms and noncircular orbits; and incorporation of known characteristics of the imager and patient that are conventionally discarded. This symposium features experts in 3D image reconstruction, image quality assessment, and the translation of such methods to emerging clinical applications. Dr. Chen will address novel methods for the incorporation of prior information in 3D and 4D CT reconstruction techniques. Dr. Pan will show recent advances in optimization-based reconstruction that enable potential reduction of dose and sampling requirements. Dr. Stayman will describe a “task-based imaging” approach that leverages models of the imaging system and patient in combination with a specification of the imaging task to optimize both the acquisition and reconstruction process. Dr. Samei will describe the development of methods for image quality assessment in such nonlinear reconstruction techniques and the use of these methods to characterize and optimize image quality and dose in a spectrum of clinical

  5. Reconstruction Techniques for Sparse Multistatic Linear Array Microwave Imaging

    SciTech Connect

    Sheen, David M.; Hall, Thomas E.

    2014-06-09

    Sequentially-switched linear arrays are an enabling technology for a number of near-field microwave imaging applications. Electronically sequencing along the array axis followed by mechanical scanning along an orthogonal axis allows dense sampling of a two-dimensional aperture in near real-time. In this paper, a sparse multi-static array technique will be described along with associated Fourier-Transform-based and back-projection-based image reconstruction algorithms. Simulated and measured imaging results are presented that show the effectiveness of the sparse array technique along with the merits and weaknesses of each image reconstruction approach.

  6. The application of image enhancement techniques to remote manipulator operation

    NASA Technical Reports Server (NTRS)

    Gonzalez, R. C.

    1974-01-01

    Methods of image enhancement which can be used by an operator who is not experienced with the mechanisms of enhancement to obtain satisfactory results were designed and implemented. Investigation of transformations which operate directly on the image domain resulted in a new technique of contrast enhancement. Transformations on the Fourier transform of the original image, including such techniques as homomorphic filtering, were also investigated. The methods of communication between the enhancement system and the computer operator were analyzed, and a language was developed for use in image enhancement. A working enhancement system was then created, and is included.

  7. Automated thermal mapping techniques using chromatic image analysis

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.

    1989-01-01

    Thermal imaging techniques are introduced using a chromatic image analysis system and temperature sensitive coatings. These techniques are used for thermal mapping and surface heat transfer measurements on aerothermodynamic test models in hypersonic wind tunnels. Measurements are made on complex vehicle configurations in a timely manner and at minimal expense. The image analysis system uses separate wavelength filtered images to analyze surface spectral intensity data. The system was initially developed for quantitative surface temperature mapping using two-color thermographic phosphors but was found useful in interpreting phase change paint and liquid crystal data as well.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Automated synthesis of image processing procedures using AI planning techniques

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Mortensen, Helen

    1994-01-01

    This paper describes the Multimission VICAR (Video Image Communication and Retrieval) Planner (MVP) (Chien 1994) system, which uses artificial intelligence planning techniques (Iwasaki & Friedland, 1985, Pemberthy & Weld, 1992, Stefik, 1981) to automatically construct executable complex image processing procedures (using models of the smaller constituent image processing subprograms) in response to image processing requests made to the JPL Multimission Image Processing Laboratory (MIPL). The MVP system allows the user to specify the image processing requirements in terms of the various types of correction required. Given this information, MVP derives unspecified required processing steps and determines appropriate image processing programs and parameters to achieve the specified image processing goals. This information is output as an executable image processing program which can then be executed to fill the processing request.

  10. Advances in multimodality molecular imaging of bone structure and function

    PubMed Central

    Lambers, Floor M; Kuhn, Gisela; Müller, Ralph

    2012-01-01

    The skeleton is important to the body as a source of minerals and blood cells and provides a structural framework for strength, mobility and the protection of organs. Bone diseases and disorders can have deteriorating effects on the skeleton, but the biological processes underlying anatomical changes in bone diseases occurring in vivo are not well understood, mostly due to the lack of appropriate analysis techniques. Therefore, there is ongoing research in the development of novel in vivo imaging techniques and molecular markers that might help to gain more knowledge of these pathological pathways in animal models and patients. This perspective provides an overview of the latest developments in molecular imaging applied to bone. It emphasizes that multimodality imaging, the combination of multiple imaging techniques encompassing different image modalities, enhances the interpretability of data, and is imperative for the understanding of the biological processes and the associated changes in bone structure and function relationships in vivo. PMID:27127622

  11. Advanced imaging and arthroscopic management of shoulder contracture after birth palsy.

    PubMed

    Kozin, Scott H; Zlotolow, Dan A

    2012-11-01

    Modern imaging techniques applied to the pediatric glenohumeral joint have advanced understanding of the anatomic changes that occur secondary to muscular imbalance after brachial plexus birth palsy. A better understanding of the progression and timing of glenohumeral dysplasia has also increased awareness and vigilance of this problem. Early detection of glenohumeral joint subluxation is now possible, allowing for prompt treatment with closed, arthroscopic, or open joint reduction with and without tendon transfers. Dynamic ultrasound imaging, Botox, and arthroscopic techniques have expanded treatment options, providing minimally invasive methods to successfully manage glenohumeral joint dysplasia. PMID:23101604

  12. Advanced Image Processing of Aerial Imagery

    NASA Technical Reports Server (NTRS)

    Woodell, Glenn; Jobson, Daniel J.; Rahman, Zia-ur; Hines, Glenn

    2006-01-01

    Aerial imagery of the Earth is an invaluable tool for the assessment of ground features, especially during times of disaster. Researchers at the NASA Langley Research Center have developed techniques which have proven to be useful for such imagery. Aerial imagery from various sources, including Langley's Boeing 757 Aries aircraft, has been studied extensively. This paper discusses these studies and demonstrates that better-than-observer imagery can be obtained even when visibility is severely compromised. A real-time, multi-spectral experimental system will be described and numerous examples will be shown.

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

    PubMed Central

    Abi-Jaoudeh, Nadine; Kruecker, Jochen; Kadoury, Samuel; Kobeiter, Hicham; Venkatesan, Aradhana M.; Levy, Elliot; Wood, Bradford J.

    2012-01-01

    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. PET, MRI and contrast enhanced 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. PMID:22851166

  14. Recent Advances in Imaging of Small and Large Bowel.

    PubMed

    Das, Chandan J; Manchanda, Smita; Panda, Ananya; Sharma, Anshul; Gupta, Arun K

    2016-01-01

    The diagnosis of bowel pathology is challenging in view of the nonspecific clinical presentation. Currently, there are various imaging modalities available to reach an accurate diagnosis. These modalities include conventional techniques (radiographs, small bowel follow-through, conventional enteroclysis), ultrasonography, and cross-sectional examinations (computed tomography [CT] and MR imaging) as well as functional imaging modalities, such as PET-CT or PET-MR imaging. Each modality has its own advantages and disadvantages and can be used in isolation or combination. This review discusses the role of CT, MR imaging, and PET-CT in the evaluation of small and large bowel diseases. PMID:26590441

  15. Detection of blue-white veil areas in dermoscopy images using machine learning techniques

    NASA Astrophysics Data System (ADS)

    Celebi, M. E.; Kingravi, Hassan A.; Aslandogan, Y. A.; Stoecker, William V.

    2006-03-01

    As a result of the advances in skin imaging technology and the development of suitable image processing techniques, during the last decade, there has been a significant increase of interest in the computer-aided diagnosis of skin cancer. Dermoscopy is a non-invasive skin imaging technique which permits visualization of features of pigmented melanocytic neoplasms that are not discernable by examination with the naked eye. One of the useful features in dermoscopic diagnosis is the blue-white veil (irregular, structureless areas of confluent blue pigmentation with an overlying white "ground-glass" film) which is mostly associated with invasive melanoma. In this preliminary study, a machine learning approach to the detection of blue-white veil areas in dermoscopy images is presented. The method involves pixel classification based on relative and absolute color features using a decision tree classifier. Promising results were obtained on a set of 224 dermoscopy images.

  16. Imaging spectrometer technologies for advanced Earth remote sensing

    NASA Technical Reports Server (NTRS)

    Wellman, J. B.; Breckinridge, J. B.; Kuperfman, P.; Salazar, R. P.; Sigurdson, K. B.

    1982-01-01

    A major requirement of multispectral imaging systems for advanced Earth remote sensing is the provision for greater spectral resolution and more versatile spectral band selection. The imaging spectrometer instrument concept provides this versatility by the combination of pushbroom imaging and spectrally dispersing optics using area array detectors in the focal plane. The shuttle imaging spectrometer concept achieves 10- and 20-meter ground instantaneous fields of view with 20-nanometer spectral resolution from Earth Orbit. Onboard processing allows the selection of spectral bands during flight; this, in turn, permits the sensor parameters to be tailored to the experiment objectives. Advances in optical design, infrared detector arrays, and focal plane cooling indicate the feasibility of the instrument concept and support the practicability of a validation flight experiment for the shuttle in the late 1980s.

  17. Recent Advances in Molecular, Multimodal and Theranostic Ultrasound Imaging

    PubMed Central

    Kiessling, Fabian; Fokong, Stanley; Bzyl, Jessica; Lederle, Wiltrud; Palmowski, Moritz; Lammers, Twan

    2014-01-01

    Ultrasound (US) imaging is an exquisite tool for the non-invasive and real-time diagnosis of many different diseases. In this context, US contrast agents can improve lesion delineation, characterization and therapy response evaluation. US contrast agents are usually micrometer-sized gas bubbles, stabilized with soft or hard shells. By conjugating antibodies to the microbubble (MB) surface, and by incorporating diagnostic agents, drugs or nucleic acids into or onto the MB shell, molecular, multimodal and theranostic MB can be generated. We here summarize recent advances in molecular, multimodal and theranostic US imaging, and introduce concepts how such advanced MB can be generated, applied and imaged. Examples are given for their use to image and treat oncological, cardiovascular and neurological diseases. Furthermore, we discuss for which therapeutic entities incorporation into (or conjugation to) MB is meaningful, and how US-mediated MB destruction can increase their extravasation, penetration, internalization and efficacy. PMID:24316070

  18. Imaging spectrometer technologies for advanced earth remote sensing

    NASA Technical Reports Server (NTRS)

    Wellman, J. B.; Breckinridge, J. B.; Kupferman, P.; Salazar, R. P.; Sigurdson, K. B.

    1982-01-01

    A major requirement of multispectral imaging systems for advanced earth remote sensing is the provision for greater spectral resolution and more versatile spectral band selection. The imaging spectrometer instrument concept provides this versatility by the combination of pushbroom imaging and spectrally dispersing optics using area array detectors in the focal plane. The shuttle imaging spectrometer concept achieves 10- and 20-meter ground instantaneous fields of view with 20-nanometer spectral resolution from earth orbit. Onboard processing allows the selection of spectral bands during flight; this, in turn, permits the sensor parameters to be tailored to the experiment objectives. Advances in optical design, infrared detector arrays, and focal plane cooling indicate the feasibility of the instrument concept and support the practicability of a validation flight experiment for the shuttle in the late 1980s. Previously announced in STAR as N83-28542

  19. Advanced digital detectors for neutron imaging.

    SciTech Connect

    Doty, F. Patrick

    2003-12-01

    Neutron interrogation provides unique information valuable for Nonproliferation & Materials Control and other important applications including medicine, airport security, protein crystallography, and corrosion detection. Neutrons probe deep inside massive objects to detect small defects and chemical composition, even through high atomic number materials such as lead. However, current detectors are bulky gas-filled tubes or scintillator/PM tubes, which severely limit many applications. Therefore this project was undertaken to develop new semiconductor radiation detection materials to develop the first direct digital imaging detectors for neutrons. The approach relied on new discovery and characterization of new solid-state sensor materials which convert neutrons directly to electronic signals via reactions BlO(n,a)Li7 and Li6(n,a)T.

  20. "Relative CIR": an image enhancement and visualization technique

    USGS Publications Warehouse

    Fleming, Michael D.

    1993-01-01

    Many techniques exist to spectrally and spatially enhance digital multispectral scanner data. One technique enhances an image while keeping the colors as they would appear in a color-infrared (CIR) image. This "relative CIR" technique generates an image that is both spectrally and spatially enhanced, while displaying a maximum range of colors. The technique enables an interpreter to visualize either spectral or land cover classes by their relative CIR characteristics. A relative CIR image is generated by developed spectral statistics for each class in the classifications and then, using a nonparametric approach for spectral enhancement, the means of the classes for each band are ranked. A 3 by 3 pixel smoothing filter is applied to the classification for spatial enhancement and the classes are mapped to the representative rank for each band. Practical applications of the technique include displaying an image classification product as a CIR image that was not derived directly from a spectral image, visualizing how a land cover classification would look as a CIR image, and displaying a spectral classification or intermediate product that will be used to label spectral classes.

  1. Recent advances in imaging crustal fault zones: a review

    NASA Astrophysics Data System (ADS)

    Yang, Hongfeng

    2015-04-01

    Crustal faults usually have a fault core and surrounding regions of brittle damage, forming a low-velocity zone (LVZ) in the immediate vicinity of the main slip interface. The LVZ may amplify ground motion, influence rupture propagation, and hold important information of earthquake physics. A number of geophysical and geodetic methods have been developed to derive high-resolution structure of the LVZ. Here, I review a few recent approaches, including ambient noise cross-correlation on dense across-fault arrays and GPS recordings of fault-zone trapped waves. Despite the past efforts, many questions concerning the LVZ structure remain unclear, such as the depth extent of the LVZ. High-quality data from larger and denser arrays and new seismic imaging technique using larger portion of recorded waveforms, which are currently under active development, may be able to better resolve the LVZ structure. In addition, effects of the along-strike segmentation and gradational velocity changes across the boundaries between the LVZ and the host rock on rupture propagation should be investigated by conducting comprehensive numerical experiments. Furthermore, high-quality active sources such as recently developed large-volume air-gun arrays provide a powerful tool to continuously monitor temporal changes of fault-zone properties, and thus can advance our understanding of fault zone evolution.

  2. Visualization of sound generation: special imaging techniques

    NASA Astrophysics Data System (ADS)

    Hahlweg, Cornelius F.; Skaloud, Daniel C.; Gutzmann, Holger L.; Kutz, Sascha; Rothe, Hendrik

    2013-09-01

    The present paper is dedicated to the Optics and Music session of the Novel Systems Design and Optimization XVI Conference. It is intended as an informative paper for the music enthusiasts. Included are some examples of visualization of sound generation and vibration modes of musically relevant objects and processes - record playback, an electric guitar and a wine glass - using high speed video, borescopic view and cross polarization techniques.

  3. New spectral imaging techniques for blood oximetry in the retina

    NASA Astrophysics Data System (ADS)

    Alabboud, Ied; Muyo, Gonzalo; Gorman, Alistair; Mordant, David; McNaught, Andrew; Petres, Clement; Petillot, Yvan R.; Harvey, Andrew R.

    2007-07-01

    Hyperspectral imaging of the retina presents a unique opportunity for direct and quantitative mapping of retinal biochemistry - particularly of the vasculature where blood oximetry is enabled by the strong variation of absorption spectra with oxygenation. This is particularly pertinent both to research and to clinical investigation and diagnosis of retinal diseases such as diabetes, glaucoma and age-related macular degeneration. The optimal exploitation of hyperspectral imaging however, presents a set of challenging problems, including; the poorly characterised and controlled optical environment of structures within the retina to be imaged; the erratic motion of the eye ball; and the compounding effects of the optical sensitivity of the retina and the low numerical aperture of the eye. We have developed two spectral imaging techniques to address these issues. We describe first a system in which a liquid crystal tuneable filter is integrated into the illumination system of a conventional fundus camera to enable time-sequential, random access recording of narrow-band spectral images. Image processing techniques are described to eradicate the artefacts that may be introduced by time-sequential imaging. In addition we describe a unique snapshot spectral imaging technique dubbed IRIS that employs polarising interferometry and Wollaston prism beam splitters to simultaneously replicate and spectrally filter images of the retina into multiple spectral bands onto a single detector array. Results of early clinical trials acquired with these two techniques together with a physical model which enables oximetry map are reported.

  4. Technique development for photoacoustic imaging guided interventions

    NASA Astrophysics Data System (ADS)

    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.

  5. Advances in Poly(4-aminodiphenylaniline) Nanofibers Preparation by Electrospinning Technique.

    PubMed

    Della Pina, C; Busacca, C; Frontera, P; Antonucci, P L; Scarpino, L A; Sironi, A; Falletta, E

    2016-05-01

    Polyaniline (PANI) nanofibers are drawing a great deal of interest from academia and industry due to their multiple applications, especially in biomedical field. PANI nanofibers were successfully electrospun for the first time by MacDiarmid and co-workers at the beginning of the millennium and since then many efforts have been addressed to improve their quality. However, traditional PANI prepared from aniline monomer shows some drawbacks, such as presence of toxic (i.e., benzidine) and inorganic (salts and metals) co-products, that complicate polymer post-treatment, and low solubility in common organic solvents, making hard its processing by electrospinning technique. Some industrial sectors, such as medical and biomedical, need to employ materials free from toxic and polluting species. In this regard, the oxidative polymerization of N-(4-aminophenyl)aniline, aniline dimer, to produce poly(4-aminodiphenylaniline), P4ADA, a kind of PANI, represents an innovative alternative to the traditional synthesis because the obtained polymer results free from carcinogenic and/or polluting co-products, and, moreover, more soluble than traditional PANI. This latter feature can be exploited to obtain P4ADA nanofibers by electrospinning technique. In this paper we report the advances obtained in the P4ADA nanofibers electrospinnig. A comparison among polyethylene oxide (PEO), polymethyl methacrylate (PMMA) and polystyrene (PS), as the second polymer to facilitate the electrospinning process, is shown. In order to increase the conductivity of P4ADA nanofibers, two strategies were adopted and compared: selective insulating binder removal from electrospun nanofibers by a rinsing tratment, afterwards optimizing the minimum amount of binder necessary for the electrospinning process. Moreover, the effect of PEO/P4ADA weight ratio on the fibers morphology and conductivity was highlighted. PMID:27483933

  6. A review of hemorheology: Measuring techniques and recent advances

    NASA Astrophysics Data System (ADS)

    Sousa, Patrícia C.; Pinho, Fernando T.; Alves, Manuel A.; Oliveira, Mónica S. N.

    2016-02-01

    Significant progress has been made over the years on the topic of hemorheology, not only in terms of the development of more accurate and sophisticated techniques, but also in terms of understanding the phenomena associated with blood components, their interactions and impact upon blood properties. The rheological properties of blood are strongly dependent on the interactions and mechanical properties of red blood cells, and a variation of these properties can bring further insight into the human health state and can be an important parameter in clinical diagnosis. In this article, we provide both a reference for hemorheological research and a resource regarding the fundamental concepts in hemorheology. This review is aimed at those starting in the field of hemodynamics, where blood rheology plays a significant role, but also at those in search of the most up-to-date findings (both qualitative and quantitative) in hemorheological measurements and novel techniques used in this context, including technical advances under more extreme conditions such as in large amplitude oscillatory shear flow or under extensional flow, which impose large deformations comparable to those found in the microcirculatory system and in diseased vessels. Given the impressive rate of increase in the available knowledge on blood flow, this review is also intended to identify areas where current knowledge is still incomplete, and which have the potential for new, exciting and useful research. We also discuss the most important parameters that can lead to an alteration of blood rheology, and which as a consequence can have a significant impact on the normal physiological behavior of blood.

  7. Advances in Clinical and Biomedical Applications of Photoacoustic Imaging

    PubMed Central

    Su, Jimmy L.; Wang, Bo; Wilson, Katheryne E.; Bayer, Carolyn L.; Chen, Yun-Sheng; Kim, Seungsoo; Homan, Kimberly A.; Emelianov, Stanislav Y.

    2010-01-01

    Importance of the field Photoacoustic imaging is an imaging modality that derives image contrast from the optical absorption coefficient of the tissue being imaged. The imaging technique is able to differentiate between healthy and diseased tissue with either deeper penetration or higher resolution than other functional imaging modalities currently available. From a clinical standpoint, photoacoustic imaging has demonstrated safety and effectiveness in diagnosing diseased tissue regions using either endogenous tissue contrast or exogenous contrast agents. Furthermore, the potential of photoacoustic imaging has been demonstrated in various therapeutic interventions ranging from drug delivery and release to image-guided therapy and monitoring. Areas covered in this review This article reviews the current state of photoacoustic imaging in biomedicine from a technological perspective, highlights various biomedical and clinical applications of photoacoustic imaging, and gives insights on future directions. What the reader will gain Readers will learn about the various applications of photoacoustic imaging, as well as the various contrast agents that can be used to assist photoacoustic imaging. This review will highlight both pre-clinical and clinical uses for photoacoustic imaging, as well as discuss some of the challenges that must be addressed to move photoacoustic imaging into the clinical realm. Take home message Photoacoustic imaging offers unique advantages over existing imaging modalities. The imaging field is broad with many exciting applications for detecting and diagnosing diseased tissue or processes. Photoacoustics is also used in therapeutic applications to identify and characterize the pathology and then to monitor the treatment. Although the technology is still in its infancy, much work has been done in the pre-clinical arena, and photoacoustic imaging is fast approaching the clinical setting. PMID:21344060

  8. Advanced endoscopic imaging of indeterminate biliary strictures

    PubMed Central

    Tabibian, James H; Visrodia, Kavel H; Levy, Michael J; Gostout, Christopher J

    2015-01-01

    Endoscopic evaluation of indeterminate biliary strictures (IDBSs) has evolved considerably since the development of flexible fiberoptic endoscopes over 50 years ago. Endoscopic retrograde cholangiography pancreatography (ERCP) was introduced nearly a decade later and has since become the mainstay of therapy for relieving obstruction of the biliary tract. However, longstanding methods of ERCP-guided tissue acquisition (i.e., biliary brushings for cytology and intraductal forceps biopsy for histology) have demonstrated disappointing performance characteristics in distinguishing malignant from benign etiologies of IDBSs. The limitations of these methods have thus helped drive the search for novel techniques to enhance the evaluation of IDBSs and thereby improve diagnosis and clinical care. These modalities include, but are not limited to, endoscopic ultrasound, intraductal ultrasound, cholangioscopy, confocal endomicroscopy, and optical coherence tomography. In this review, we discuss established and emerging options in the evaluation of IDBSs. PMID:26675379

  9. Studies of EGRET sources with a novel image restoration technique

    SciTech Connect

    Tajima, Hiroyasu; Cohen-Tanugi, Johann; Kamae, Tuneyoshi; Finazzi, Stefano; Chiang, James

    2007-07-12

    We have developed an image restoration technique based on the Richardson-Lucy algorithm optimized for GLAST-LAT image analysis. Our algorithm is original since it utilizes the PSF (point spread function) that is calculated for each event. This is critical for EGRET and GLAST-LAT image analysis since the PSF depends on the energy and angle of incident gamma-rays and varies by more than one order of magnitude. EGRET and GLAST-LAT image analysis also faces Poisson noise due to low photon statistics. Our technique incorporates wavelet filtering to minimize noise effects. We present studies of EGRET sources using this novel image restoration technique for possible identification of extended gamma-ray sources.

  10. Studies of EGRET sources with a novel image restoration technique

    NASA Astrophysics Data System (ADS)

    Tajima, Hiroyasu; Finazzi, Stefano; Cohen-Tanugi, Johann; Chiang, James; Kamae, Tuneyoshi

    2007-07-01

    We have developed an image restoration technique based on the Richardson-Lucy algorithm optimized for GLAST-LAT image analysis. Our algorithm is original since it utilizes the PSF (point spread function) that is calculated for each event. This is critical for EGRET and GLAST-LAT image analysis since the PSF depends on the energy and angle of incident gamma-rays and varies by more than one order of magnitude. EGRET and GLAST-LAT image analysis also faces Poisson noise due to low photon statistics. Our technique incorporates wavelet filtering to minimize noise effects. We present studies of EGRET sources using this novel image restoration technique for possible identification of extended gamma-ray sources.

  11. Characterization of burns using hyperspectral imaging technique - a preliminary study.

    PubMed

    Calin, Mihaela Antonina; Parasca, Sorin Viorel; Savastru, Roxana; Manea, Dragos

    2015-02-01

    Surgical burn treatment depends on accurate estimation of burn depth. Many methods have been used to asses burns, but none has gained wide acceptance. Hyperspectral imaging technique has recently entered the medical research field with encouraging results. In this paper we present a preliminary study (case presentation) that aims to point out the value of this optical method in burn wound characterization and to set up future lines of investigation. A hyperspectral image of a leg and foot with partial thickness burns was obtained in the fifth postburn day. The image was analyzed using linear spectral unmixing model as a tool for mapping the investigated areas. The article gives details on the mathematical bases of the interpretation model and correlations with clinical examination pointing out the advantages of hyperspectral imaging technique. While the results were encouraging, further more extended and better founded studies are being prepared before recognizing hyperspectral imaging technique as an applicable method of burn wound assessment. PMID:24997530

  12. Removing baseline flame's spectrum by using advanced recovering spectrum techniques.

    PubMed

    Arias, Luis; Sbarbaro, Daniel; Torres, Sergio

    2012-09-01

    In this paper, a novel automated algorithm to estimate and remove the continuous baseline from measured flame spectra is proposed. The algorithm estimates the continuous background based on previous information obtained from a learning database of continuous flame spectra. Then, the discontinuous flame emission is calculated by subtracting the estimated continuous baseline from the measured spectrum. The key issue subtending the learning database is that the continuous flame emissions are predominant in the sooty regions, in absence of discontinuous radiation. The proposed algorithm was tested using natural gas and bio-oil flames spectra at different combustion conditions, and the goodness-of-fit coefficient (GFC) quality metric was used to quantify the performance in the estimation process. Additionally, the commonly used first derivative method (FDM) for baseline removing was applied to the same testing spectra in order to compare and to evaluate the proposed technique. The achieved results show that the proposed method is a very attractive tool for designing advanced combustion monitoring strategies of discontinuous emissions. PMID:22945158

  13. Nanocrystalline materials: recent advances in crystallographic characterization techniques

    PubMed Central

    Ringe, Emilie

    2014-01-01

    Most properties of nanocrystalline materials are shape-dependent, providing their exquisite tunability in optical, mechanical, electronic and catalytic properties. An example of the former is localized surface plasmon resonance (LSPR), the coherent oscillation of conduction electrons in metals that can be excited by the electric field of light; this resonance frequency is highly dependent on both the size and shape of a nanocrystal. An example of the latter is the marked difference in catalytic activity observed for different Pd nanoparticles. Such examples highlight the importance of particle shape in nanocrystalline materials and their practical applications. However, one may ask ‘how are nanoshapes created?’, ‘how does the shape relate to the atomic packing and crystallography of the material?’, ‘how can we control and characterize the external shape and crystal structure of such small nanocrystals?’. This feature article aims to give the reader an overview of important techniques, concepts and recent advances related to these questions. Nucleation, growth and how seed crystallography influences the final synthesis product are discussed, followed by shape prediction models based on seed crystallography and thermodynamic or kinetic parameters. The crystallographic implications of epitaxy and orientation in multilayered, core-shell nanoparticles are overviewed, and, finally, the development and implications of novel, spatially resolved analysis tools are discussed. PMID:25485133

  14. Pediatric Cardiopulmonary Resuscitation: Advances in Science, Techniques, and Outcomes

    PubMed Central

    Topjian, Alexis A.; Berg, Robert A.; Nadkarni, Vinay M.

    2009-01-01

    More than 25% of children survive to hospital discharge after in-hospital cardiac arrests, and 5% to 10% survive after out-of-hospital cardiac arrests. This review of pediatric cardiopulmonary resuscitation addresses the epidemiology of pediatric cardiac arrests, mechanisms of coronary blood flow during cardiopulmonary resuscitation, the 4 phases of cardiac arrest resuscitation, appropriate interventions during each phase, special resuscitation circumstances, extracorporeal membrane oxygenation cardiopulmonary resuscitation, and quality of cardiopulmonary resuscitation. The key elements of pathophysiology that impact and match the timing, intensity, duration, and variability of the hypoxic-ischemic insult to evidence-based interventions are reviewed. Exciting discoveries in basic and applied-science laboratories are now relevant for specific subpopulations of pediatric cardiac arrest victims and circumstances (eg, ventricular fibrillation, neonates, congenital heart disease, extracorporeal cardiopulmonary resuscitation). Improving the quality of interventions is increasingly recognized as a key factor for improving outcomes. Evolving training strategies include simulation training, just-in-time and just-in-place training, and crisis-team training. The difficult issue of when to discontinue resuscitative efforts is addressed. Outcomes from pediatric cardiac arrests are improving. Advances in resuscitation science and state-of-the-art implementation techniques provide the opportunity for further improvement in outcomes among children after cardiac arrest. PMID:18977991

  15. Development of advanced strain diagnostic techniques for reactor environments.

    SciTech Connect

    Fleming, Darryn D.; Holschuh, Thomas Vernon,; Miller, Timothy J.; Hall, Aaron Christopher; Urrea, David Anthony,; Parma, Edward J.,

    2013-02-01

    The following research is operated as a Laboratory Directed Research and Development (LDRD) initiative at Sandia National Laboratories. The long-term goals of the program include sophisticated diagnostics of advanced fuels testing for nuclear reactors for the Department of Energy (DOE) Gen IV program, with the future capability to provide real-time measurement of strain in fuel rod cladding during operation in situ at any research or power reactor in the United States. By quantifying the stress and strain in fuel rods, it is possible to significantly improve fuel rod design, and consequently, to improve the performance and lifetime of the cladding. During the past year of this program, two sets of experiments were performed: small-scale tests to ensure reliability of the gages, and reactor pulse experiments involving the most viable samples in the Annulated Core Research Reactor (ACRR), located onsite at Sandia. Strain measurement techniques that can provide useful data in the extreme environment of a nuclear reactor core are needed to characterize nuclear fuel rods. This report documents the progression of solutions to this issue that were explored for feasibility in FY12 at Sandia National Laboratories, Albuquerque, NM.

  16. Ultrasound imaging techniques in density separation of polyolefin waste.

    PubMed

    Sanaee, Seyed Ali; Bakker, M C M

    2012-12-01

    Ultrasound imaging techniques are investigated using a multi-element sensor array for purposes of monitoring and measurement ofpolyolefin waste particles inside the black ferrous liquid ofa magnetic density separator (MDS). A medical ultrasound imaging system with real-time capability was adapted first to assess the potential of imaging technology inside the MDS. An image processing routine was developed to determine the depth distribution of the detected particles as they are carried by the flow in the MDS channel. This real-time information is vital for optimizing the splitter position, which directly influences quality and recovery of the MDS polyolefin products. Despite successes in the laboratory, the medical technology proved unsatisfactory for continuous high-quality image forming in the industrial set-up as it requires regular operator intervention. Therefore, research has been initiated into alternative imaging methods, which are also being investigated in other fields such as non-destructive testing and geophysics. The influence of different ultrasound datasets and related image-forming techniques were investigated, for which dedicated algorithms were implemented in Matlab. The main advantages and disadvantages of the different techniques are addressed. It is concluded that the alternative imaging methods may be more robust and deliver higher image quality compared to the commercial medical imager. In particular, sizing of polyolefin particles may improve significantly if the method takes into account the correct ultrasound velocities of both the ferrous liquid and the immersed polyolefin particles. PMID:23437658

  17. A fuzzy optimal threshold technique for medical images

    NASA Astrophysics Data System (ADS)

    Thirupathi Kannan, Balaji; Krishnasamy, Krishnaveni; Pradeep Kumar Kenny, S.

    2012-01-01

    A new fuzzy based thresholding method for medical images especially cervical cytology images having blob and mosaic structures is proposed in this paper. Many existing thresholding algorithms may segment either blob or mosaic images but there aren't any single algorithm that can do both. In this paper, an input cervical cytology image is binarized, preprocessed and the pixel value with minimum Fuzzy Gaussian Index is identified as an optimal threshold value and used for segmentation. The proposed technique is tested on various cervical cytology images having blob or mosaic structures, compared with various existing algorithms and proved better than the existing algorithms.

  18. A fuzzy optimal threshold technique for medical images

    NASA Astrophysics Data System (ADS)

    Thirupathi Kannan, Balaji; Krishnasamy, Krishnaveni; Pradeep Kumar Kenny, S.

    2011-12-01

    A new fuzzy based thresholding method for medical images especially cervical cytology images having blob and mosaic structures is proposed in this paper. Many existing thresholding algorithms may segment either blob or mosaic images but there aren't any single algorithm that can do both. In this paper, an input cervical cytology image is binarized, preprocessed and the pixel value with minimum Fuzzy Gaussian Index is identified as an optimal threshold value and used for segmentation. The proposed technique is tested on various cervical cytology images having blob or mosaic structures, compared with various existing algorithms and proved better than the existing algorithms.

  19. Visualisation of Ecohydrological Processes and Relationships for Teaching Using Advanced Techniques

    NASA Astrophysics Data System (ADS)

    Guan, H.; Wang, H.; Gutierrez-Jurado, H. A.; Yang, Y.; Deng, Z.

    2014-12-01

    Ecohydrology is an emerging discipline with a rapid research growth. This calls for enhancing ecohydrology education in both undergraduate and postgraduate levels. In other hydrology disciplines, hydrological processes are commonly observed in environments (e.g. streamflow, infiltration) or easily demonstrated in labs (e.g. Darcy's column). It is relatively difficult to demonstrate ecohydrological concepts and processes (e.g. soil-vegetation water relationship) in teaching. In this presentation, we report examples of using some advanced techniques to illustrate ecohydrological concepts, relationships, and processes, with measurements based on a native vegetation catchment in South Australia. They include LIDAR images showing the relationship between topography-control hdyroclimatic conditions and vegetation distribution, electrical resistivity tomography derived images showing stem structures, continuous stem water potential monitoring showing diurnal variations of plant water status, root zone moisture depletion during dry spells, and responses to precipitation inputs, and incorporating sapflow measurements to demonstrate environmental stress on plant stomatal behaviours.

  20. Hybrid inverse lithography techniques for advanced hierarchical memories

    NASA Astrophysics Data System (ADS)

    Xiao, Guangming; Hooker, Kevin; Irby, Dave; Zhang, Yunqiang; Ward, Brian; Cecil, Tom; Hall, Brett; Lee, Mindy; Kim, Dave; Lucas, Kevin

    2014-03-01

    Traditional segment-based model-based OPC methods have been the mainstream mask layout optimization techniques in volume production for memory and embedded memory devices for many device generations. These techniques have been continually optimized over time to meet the ever increasing difficulties of memory and memory periphery patterning. There are a range of difficult issues for patterning embedded memories successfully. These difficulties include the need for a very high level of symmetry and consistency (both within memory cells themselves and between cells) due to circuit effects such as noise margin requirements in SRAMs. Memory cells and access structures consume a large percentage of area in embedded devices so there is a very high return from shrinking the cell area as much as possible. This aggressive scaling leads to very difficult resolution, 2D CD control and process window requirements. Additionally, the range of interactions between mask synthesis corrections of neighboring areas can extend well beyond the size of the memory cell, making it difficult to fully take advantage of the inherent designed cell hierarchy in mask pattern optimization. This is especially true for non-traditional (i.e., less dependent on geometric rule) OPC/RET methods such as inverse lithography techniques (ILT) which inherently have more model-based decisions in their optimizations. New inverse methods such as model-based SRAF placement and ILT are, however, well known to have considerable benefits in finding flexible mask pattern solutions to improve process window, improve 2D CD control, and improve resolution in ultra-dense memory patterns. They also are known to reduce recipe complexity and provide native MRC compliant mask pattern solutions. Unfortunately, ILT is also known to be several times slower than traditional OPC methods due to the increased computational lithographic optimizations it performs. In this paper, we describe and present results for a methodology to

  1. Synergistic combination technique for SAR image classification

    NASA Astrophysics Data System (ADS)

    Burman, Bhaskar

    1998-07-01

    Classification of earth terrain from satellite radar imagery represents an important and continually developing application of microwave remote sensing. The basic objective of this paper is to derive more information, through combining, than is present in any individual element of input data. Multispectral data has been used to provide complementary information so as to utilize a single SAR data for the purpose of land-cover classification. More recently neural networks have been applied to a number of image classification problems and have shown considerable success in exceeding the performance of conventional algorithms. In this work, a comparison study has been carried out between a conventional Maximum Likelihood (ML) classifier and a neural network (back-error-propagation) classifier in terms of classification accuracy. The results reveal that the combination of SAR and MSS data of the same scene produced better classification accuracy than either alone and the neural network classification has an edge over the conventional classification scheme.

  2. Taking the perfect nuclear image: quality control, acquisition, and processing techniques for cardiac SPECT, PET, and hybrid imaging.

    PubMed

    Case, James A; Bateman, Timothy M

    2013-10-01

    Nuclear Cardiology for the past 40 years has distinguished itself in its ability to non-invasively assess regional myocardial blood flow and identify obstructive coronary disease. This has led to advances in managing the diagnosis, risk stratification, and prognostic assessment of cardiac patients. These advances have all been predicated on the collection of high quality nuclear image data. National and international professional societies have established guidelines for nuclear laboratories to maintain high quality nuclear cardiology services. In addition, laboratory accreditation has further advanced the goal of the establishing high quality standards for the provision of nuclear cardiology services. This article summarizes the principles of nuclear cardiology single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging and techniques for maintaining quality: from the calibration of imaging equipment to post processing techniques. It also will explore the quality considerations of newer technologies such as cadmium zinc telleride (CZT)-based SPECT systems and absolute blood flow measurement techniques using PET. PMID:23868070

  3. AXIOM: Advanced X-ray imaging of the magnetosheath

    NASA Astrophysics Data System (ADS)

    Sembay, S.; Branduardi-Raymont, G.; Eastwood, J. P.; Sibeck, D. G.; Abbey, A.; Brown, P.; Carter, J. A.; Carr, C. M.; Forsyth, C.; Kataria, D.; Kemble, S.; Milan, S.; Owen, C. J.; Read, A. M.; Peacocke, L.; Arridge, C. S.; Coates, A. J.; Collier, M. R.; Cowley, S. W. H.; Fazakerley, A. N.; Fraser, G.; Jones, G. H.; Lallement, R.; Lester, M.; Porter, F. S.; Yeoman, T.

    2012-04-01

    AXIOM (Advanced X-ray Imaging Of the Magnetosphere) is a concept mission which aims to explain how the Earth's magnetosphere responds to the changing impact of the solar wind using a unique method never attempted before; performing wide-field soft X-ray imaging and spectroscopy of the magnetosheath, magnetopause and bow shock at high spatial and temporal resolution. Global imaging of these regions is possible because of the solar wind charge exchange (SWCX) process which produces elevated soft X-ray emission from the interaction of high charge-state solar wind ions with primarily neutral hydrogen in the Earth's exosphere and near-interplanetary space.

  4. The ADIS advanced data acquisition, imaging, and storage system

    SciTech Connect

    Flaherty, J.W.

    1986-01-01

    The design and development of Automated Ultrasonic Scanning Systems (AUSS) by McDonnell Aircraft Company has provided the background for the development of the ADIS advanced data acquisition, imaging, and storage system. The ADIS provides state-of-the-art ultrasonic data processing and imaging features which can be utilized in both laboratory and production line composite evaluation applications. System features, such as, real-time imaging, instantaneous electronic rescanning, multitasking capability, histograms, and cross-sections, provide the tools necessary to inspect and evaluate composite parts quickly and consistently.

  5. AXIOM: Advanced X-Ray Imaging Of the Magnetosheath

    NASA Technical Reports Server (NTRS)

    Sembay, S.; Branduardi-Rayrnont, G.; Eastwood, J. P.; Sibeck, D. G.; Abbey, A.; Brown, P.; Carter, J. A.; Carr, C. M.; Forsyth, C; Kataria, D.; Kemble, S.; Milan, S.; Owen, C. J.; Read, A. M.; Peacocke, L.; Arridge, C. S.; Coates, A. J.; Collier, M. R.; Cowley, S. W. H.; Fazakerley, A. N.; Fraser, G.; Jones, G. H.; Lallement, R.; Lester, M.; Porter, F. S.

    2012-01-01

    AXIOM (Advanced X-ray Imaging Of the Magnetosphere) is a concept mission which aims to explain how the Earth's magnetosphere responds to the changing impact of the solar wind using a unique method never attempted before; performing wide-field soft X-ray imaging and spectroscopy of the magnetosheath. magnetopause and bow shock at high spatial and temporal resolution. Global imaging of these regions is possible because of the solar wind charge exchange (SWCX) process which produces elevated soft X-ray emission from the interaction of high charge-state solar wind ions with primarily neutral hydrogen in the Earth's exosphere and near-interplanetary space.

  6. In-flight performance of the Japanese Advanced Meteorological Imager

    NASA Astrophysics Data System (ADS)

    Puschell, Jeffrey J.; Osgood, Roderic; Auchter, Joseph; Hurt, W. Todd; Hitomi, Miyamoto; Sasaki, Masayuki; Tahara, Yoshihiko; Tadros, Alfred; Faller, Ken; Mclaren, Mark; Sheffield, Jonathan; Gaiser, John; Kamel, Ahmed; Gunshor, Mathew

    2006-08-01

    The Japanese Advanced Meteorological Imager (JAMI) was developed by Raytheon and delivered to Space Systems/Loral as the Imager Subsystem for Japan's MTSAT-1R satellite. MTSAT-1R was launched from the Tanegashima Space Center on 2005 February 26 and became formally operational on 2005 June 28. This paper compares in-flight performance of JAMI with predictions made before launch. The performance areas discussed include radiometric sensitivity (NEDT and SNR) versus spectral channel, calibration accuracy versus spectral channel derived from comparisons of JAMI and AIRS measurements and image navigation and registration.

  7. Image process technique used in a large FOV compound eye imaging system

    NASA Astrophysics Data System (ADS)

    Cao, Axiu; Shi, Lifang; Shi, Ruiying; Deng, Qiling; Du, Chunlei

    2012-11-01

    Biological inspiration has produced some successful solutions for different imaging systems. Inspired by the compound eye of insects, this paper presents some image process techniques used in the spherical compound eye imaging system. By analyzing the relationship between the system with large field of view (FOV) and each lens, an imaging system based on compound eyes has been designed, where 37 lenses pointing in different directions are arranged on a spherical substrate. By researching the relationship between the lens position and the corresponding image geometrical shape to realize a large FOV detection, the image process technique is proposed. To verify the technique, experiments are carried out based on the designed compound eye imaging system. The results show that an image with FOV over 166° can be acquired while keeping excellent image process quality.

  8. Reconstruction techniques for sparse multistatic linear array microwave imaging

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Hall, Thomas E.

    2014-06-01

    Sequentially-switched linear arrays are an enabling technology for a number of near-field microwave imaging applications. Electronically sequencing along the array axis followed by mechanical scanning along an orthogonal axis allows dense sampling of a two-dimensional aperture in near real-time. The Pacific Northwest National Laboratory (PNNL) has developed this technology for several applications including concealed weapon detection, groundpenetrating radar, and non-destructive inspection and evaluation. These techniques form three-dimensional images by scanning a diverging beam swept frequency transceiver over a two-dimensional aperture and mathematically focusing or reconstructing the data into three-dimensional images. Recently, a sparse multi-static array technology has been developed that reduces the number of antennas required to densely sample the linear array axis of the spatial aperture. This allows a significant reduction in cost and complexity of the linear-array-based imaging system. The sparse array has been specifically designed to be compatible with Fourier-Transform-based image reconstruction techniques; however, there are limitations to the use of these techniques, especially for extreme near-field operation. In the extreme near-field of the array, back-projection techniques have been developed that account for the exact location of each transmitter and receiver in the linear array and the 3-D image location. In this paper, the sparse array technique will be described along with associated Fourier-Transform-based and back-projection-based image reconstruction algorithms. Simulated imaging results are presented that show the effectiveness of the sparse array technique along with the merits and weaknesses of each image reconstruction approach.

  9. Advances in Current Rating Techniques for Flexible Printed Circuits

    NASA Technical Reports Server (NTRS)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

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

    NASA Astrophysics Data System (ADS)

    Nakahira, Kenji; Miyamoto, Atsushi; Honda, Toshifumi

    2014-12-01

    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.

  11. Using image processing techniques on proximity probe signals in rotordynamics

    NASA Astrophysics Data System (ADS)

    Diamond, Dawie; Heyns, Stephan; Oberholster, Abrie

    2016-06-01

    This paper proposes a new approach to process proximity probe signals in rotordynamic applications. It is argued that the signal be interpreted as a one dimensional image. Existing image processing techniques can then be used to gain information about the object being measured. Some results from one application is presented. Rotor blade tip deflections can be calculated through localizing phase information in this one dimensional image. It is experimentally shown that the newly proposed method performs more accurately than standard techniques, especially where the sampling rate of the data acquisition system is inadequate by conventional standards.

  12. A machine vision identification technique from range images

    NASA Technical Reports Server (NTRS)

    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.

  13. ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS

    SciTech Connect

    Louis J. Durlofsky; Khalid Aziz

    2004-08-20

    Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow in the wellbore

  14. Optical brain imaging in vivo: techniques and applications from animal to man

    PubMed Central

    Hillman, Elizabeth M. C.

    2008-01-01

    Optical brain imaging has seen 30 years of intense development, and has grown into a rich and diverse field. In-vivo imaging using light provides unprecedented sensitivity to functional changes through intrinsic contrast, and is rapidly exploiting the growing availability of exogenous optical contrast agents. Light can be used to image microscopic structure and function in vivo in exposed animal brain, while also allowing noninvasive imaging of hemodynamics and metabolism in a clinical setting. This work presents an overview of the wide range of approaches currently being applied to in-vivo optical brain imaging, from animal to man. Techniques include multispectral optical imaging, voltage sensitive dye imaging and speckle-flow imaging of exposed cortex, in-vivo two-photon microscopy of the living brain, and the broad range of noninvasive topography and tomography approaches to near-infrared imaging of the human brain. The basic principles of each technique are described, followed by examples of current applications to cutting-edge neuroscience research. In summary, it is shown that optical brain imaging continues to grow and evolve, embracing new technologies and advancing to address ever more complex and important neuroscience questions. PMID:17994863

  15. Weldability and joining techniques for advanced fossil energy system alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Liu, W.; Yang, D.; Zhou, G.; Morrison, M.

    1998-05-01

    The efforts represent the concerns for the basic understanding of the weldability and fabricability of the advanced high temperature alloys so necessary to affect increases in the efficiency of the next generation Fossil Energy Power Plants. The effort was divided into three tasks with the first effort dealing with the welding and fabrication behavior of 310HCbN (HR3C), the second task details the studies aimed at understanding the weldability of a newly developed 310TaN high temperature stainless (a modification of 310 stainless) and Task 3 addressed the cladding of austenitic tubing with Iron-Aluminide using the GTAW process. Task 1 consisted of microstructural studies on 310HCbN and the development of a Tube Weldability test which has applications to production welding techniques as well as laboratory weldability assessments. In addition, the evaluation of ex-service 310HCbN which showed fireside erosion and cracking at the attachment weld locations was conducted. Task 2 addressed the behavior of the newly developed 310 TaN modification of standard 310 stainless steel and showed that the weldability was excellent and that the sensitization potential was minimal for normal welding and fabrication conditions. The microstructural evolution during elevated temperature testing was characterized and the second phase particles evolved upon aging were identified. Task 3 details the investigation undertaken to clad 310HCbN tubing with Iron Aluminide and developed welding conditions necessary to provide a crack free cladding. The work showed that both a preheat and a post-heat was necessary for crack free deposits and the effect of a third element on the cracking potential was defined together with the effect of the aluminum level for optimum weldability.

  16. A contrast enhancement technique for low light images

    NASA Astrophysics Data System (ADS)

    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.

  17. Nondestructive evaluation technique using infrared thermography and terahertz imaging

    NASA Astrophysics Data System (ADS)

    Sakagami, Takahide; Shiozawa, Daiki; Tamaki, Yoshitaka; Iwama, Tatsuya

    2016-05-01

    Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.

  18. Pushing CT and MR Imaging to the Molecular Level for Studying the “Omics”: Current Challenges and Advancements

    PubMed Central

    Huang, Hsuan-Ming; Shih, Yi-Yu

    2014-01-01

    During the past decade, medical imaging has made the transition from anatomical imaging to functional and even molecular imaging. Such transition provides a great opportunity to begin the integration of imaging data and various levels of biological data. In particular, the integration of imaging data and multiomics data such as genomics, metabolomics, proteomics, and pharmacogenomics may open new avenues for predictive, preventive, and personalized medicine. However, to promote imaging-omics integration, the practical challenge of imaging techniques should be addressed. In this paper, we describe key challenges in two imaging techniques: computed tomography (CT) and magnetic resonance imaging (MRI) and then review existing technological advancements. Despite the fact that CT and MRI have different principles of image formation, both imaging techniques can provide high-resolution anatomical images while playing a more and more important role in providing molecular information. Such imaging techniques that enable single modality to image both the detailed anatomy and function of tissues and organs of the body will be beneficial in the imaging-omics field. PMID:24738056

  19. Advanced techniques and technology for efficient data storage, access, and transfer

    NASA Technical Reports Server (NTRS)

    Rice, Robert F.; Miller, Warner

    1991-01-01

    Advanced techniques for efficiently representing most forms of data are being implemented in practical hardware and software form through the joint efforts of three NASA centers. These techniques adapt to local statistical variations to continually provide near optimum code efficiency when representing data without error. Demonstrated in several earlier space applications, these techniques are the basis of initial NASA data compression standards specifications. Since the techniques clearly apply to most NASA science data, NASA invested in the development of both hardware and software implementations for general use. This investment includes high-speed single-chip very large scale integration (VLSI) coding and decoding modules as well as machine-transferrable software routines. The hardware chips were tested in the laboratory at data rates as high as 700 Mbits/s. A coding module's definition includes a predictive preprocessing stage and a powerful adaptive coding stage. The function of the preprocessor is to optimally process incoming data into a standard form data source that the second stage can handle.The built-in preprocessor of the VLSI coder chips is ideal for high-speed sampled data applications such as imaging and high-quality audio, but additionally, the second stage adaptive coder can be used separately with any source that can be externally preprocessed into the 'standard form'. This generic functionality assures that the applicability of these techniques and their recent high-speed implementations should be equally broad outside of NASA.

  20. Interlaced linear array sampling technique for electromagnetic wave imaging

    SciTech Connect

    Sheen, David M; McMakin, Douglas L

    2009-06-16

    An arrangement of receivers and transmitters used in wideband holographic imaging using a reduced number of physical antenna elements compared to established techniques and systems. At least one of the receivers is configured to receive the reflected signal from three or more of transmitters, and at least one transmitter is configured to transmit a signal to an object, the reflection of which will be received by at least three receivers. The improved arrays are easily incorporated into existing microwave and millimeter wave holographic imaging equipment utilizing the existing mechanical features of this equipment, as well as the existing wideband holographic imaging algorithms and electronics for constructing images.

  1. Iterative image reconstruction techniques: cardiothoracic computed tomography applications.

    PubMed

    Cho, Young Jun; Schoepf, U Joseph; Silverman, Justin R; Krazinski, Aleksander W; Canstein, Christian; Deak, Zsuzsanna; Grimm, Jochen; Geyer, Lucas L

    2014-07-01

    Iterative image reconstruction algorithms provide significant improvements over traditional filtered back projection in computed tomography (CT). Clinically available through recent advances in modern CT technology, iterative reconstruction enhances image quality through cyclical image calculation, suppressing image noise and artifacts, particularly blooming artifacts. The advantages of iterative reconstruction are apparent in traditionally challenging cases-for example, in obese patients, those with significant artery calcification, or those with coronary artery stents. In addition, as clinical use of CT has grown, so have concerns over ionizing radiation associated with CT examinations. Through noise reduction, iterative reconstruction has been shown to permit radiation dose reduction while preserving diagnostic image quality. This approach is becoming increasingly attractive as the routine use of CT for pediatric and repeated follow-up evaluation grows ever more common. Cardiovascular CT in particular, with its focus on detailed structural and functional analyses, stands to benefit greatly from the promising iterative solutions that are readily available. PMID:24662334

  2. Establishing advanced practice for medical imaging in New Zealand

    PubMed Central

    Yielder, Jill; Young, Adrienne; Park, Shelley; Coleman, Karen

    2014-01-01

    IntroductionThis article presents the outcome and recommendations following the second stage of a role development project conducted on behalf of the New Zealand Institute of Medical Radiation Technology (NZIMRT). The study sought to support the development of profiles and criteria that may be used to formulate Advanced Scopes of Practice for the profession. It commenced in 2011, following on from initial research that occurred between 2005 and 2008 investigating role development and a possible career structure for medical radiation technologists (MRTs) in New Zealand (NZ). MethodsThe study sought to support the development of profiles and criteria that could be used to develop Advanced Scopes of Practice for the profession through inviting 12 specialist medical imaging groups in NZ to participate in a survey. ResultsFindings showed strong agreement on potential profiles and on generic criteria within them; however, there was less agreement on specific skills criteria within specialist areas. ConclusionsThe authors recommend that one Advanced Scope of Practice be developed for Medical Imaging, with the establishment of generic and specialist criteria. Systems for approval of the overall criteria package for any individual Advanced Practitioner (AP) profile, audit and continuing professional development requirements need to be established by the Medical Radiation Technologists Board (MRTB) to meet the local needs of clinical departments. It is further recommended that the NZIMRT and MRTB promote and support the need for an AP pathway for medical imaging in NZ. PMID:26229631

  3. Establishing advanced practice for medical imaging in New Zealand

    SciTech Connect

    Yielder, Jill; Young, Adrienne; Park, Shelley; Coleman, Karen

    2014-02-15

    Introduction: This article presents the outcome and recommendations following the second stage of a role development project conducted on behalf of the New Zealand Institute of Medical Radiation Technology (NZIMRT). The study sought to support the development of profiles and criteria that may be used to formulate Advanced Scopes of Practice for the profession. It commenced in 2011, following on from initial research that occurred between 2005 and 2008 investigating role development and a possible career structure for medical radiation technologists (MRTs) in New Zealand (NZ). Methods: The study sought to support the development of profiles and criteria that could be used to develop Advanced Scopes of Practice for the profession through inviting 12 specialist medical imaging groups in NZ to participate in a survey. Results: Findings showed strong agreement on potential profiles and on generic criteria within them; however, there was less agreement on specific skills criteria within specialist areas. Conclusions: The authors recommend that one Advanced Scope of Practice be developed for Medical Imaging, with the establishment of generic and specialist criteria. Systems for approval of the overall criteria package for any individual Advanced Practitioner (AP) profile, audit and continuing professional development requirements need to be established by the Medical Radiation Technologists Board (MRTB) to meet the local needs of clinical departments. It is further recommended that the NZIMRT and MRTB promote and support the need for an AP pathway for medical imaging in NZ.

  4. Investigation of joining techniques for advanced austenitic alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Kikuchi, Y.; Shi, C.; Gill, T.P.S.

    1991-05-01

    Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.

  5. Time of flight diffraction imaging for double-probe technique.

    PubMed

    Chang, Young-Fo; Hsieh, Cheng-I

    2002-06-01

    Due to rapid progress in microelectronics and computer technologies, the system evolving from analog to digital, and a programmable and flexible synthetic aperture focusing technique (SAFT) for the single-probe pulse-echo imaging technique of ultrasonic nondestructive testing (NDT) becomes feasible. The double-probe reflection technique usually is used to detect the nonhorizontal flaws in the ultrasonic NDT. Because there is an offset between the transmitter and receiver, the position and size of the flaw cannot be directly read from the image. Therefore, a digital signal processing (DSP) imaging method is proposed to process the ultrasonic image obtained by double-probe reflection technique. In the imaging, the signal is redistributed on an ellipsoid with the transmitter and receiver positions as focuses, and the traveltime sum for the echo from the ellipsoid to the focuses as the traveltime of signal. After redistributing all the signals, the useful signals can be constructively added in some point in which the reflected point is; otherwise, the signals will be destructively added. Therefore, the image resolution of the flaw can be improved and the position and size of the flaw can be estimated directly from the processed image. Based on the experimental results, the steep flaw (45 degrees) cannot be detected by the pulse echo technique but can be detected by the double-probe method, and the double-probe B-scan image of 30 degrees tilted crack is clearer than the pulse echo B-scan image. However, the flaw image departs from its true position greatly. After processing, the steep flaw image can be moved to its true position. When the flaws are not greater than the probe largely, the sizes of the flaws are difficult to be discriminated in both pulse echo and double-probe B-scan images. In the processed double-probe B-scan image, the size of the flaws can be estimated successfully, and the images of the flaws are close to their true shape. PMID:12075969

  6. Recent Advances in Cardiovascular Imaging Relevant to the Management of Patients with Suspected Cardiac Amyloidosis.

    PubMed

    White, James A; Fine, Nowell M

    2016-08-01

    Cardiac amyloidosis is a form of infiltrative cardiomyopathy typically presenting with progressive heart failure. The clinical presentation and morphological findings often overlap with other cardiovascular diseases, and frequently results in misdiagnosis and consequent under-reporting. Cardiovascular imaging is playing an increasingly important diagnostic and prognostic role in this referral population, and is reducing the reliance on endomyocardial biopsy as a confirmatory testing. Advancements across multiple cardiac imaging modalities, including echocardiography, magnetic resonance imaging, nuclear imaging, and computed tomography, are improving diagnostic accuracy and offering novel approaches to sub-type differentiation and prognostication. This review explores recent advancements in cardiac imaging for the diagnosis, typing, and staging of cardiac amyloidosis, with a focus on new and evolving techniques. Emphasis is also placed on the promise of non-invasive cardiac imaging to provide value across the spectrum of this clinical disease, from early disease identification (prior to the development of increased wall thickness) through to markers of advanced disease associated with early mortality. PMID:27319007

  7. A new x-ray imaging technique for radiography mode of flat-panel imager

    NASA Astrophysics Data System (ADS)

    Suzuki, K.; Ikeda, S.; Ueda, K.; Baba, R.

    2007-03-01

    A digital radiography system using a flat-panel imager, which has a novel imaging technique for a radiography mode, has been developed. A radiographic image captured by the new imaging technique has a wide dynamic range in comparison with conventional radiographic images. The purpose of this presentation is to show the basic performance of the image quality acquired by the new imaging technique and compare it with an image taken by a conventional technique. The flat-panel imager has a gain switching capability, normally used in a dynamic imaging mode for a cone-beam CT study. The gain switching method has two gain settings and switches between them automatically, depending on the incident dose to each pixel of flat-panel imager. As a result of the gain switching method, an image having wide dynamic range is achieved. In this study, we applied the gain switching method to the radiography mode, and achieved a radiographic image with wider dynamic range than a conventional radiograph. Furthermore, we have also developed an algorithm for calibration of the gain switching method in radiography mode.

  8. Advances in functional and structural imaging of the human lung using proton MRI.

    PubMed

    Miller, G Wilson; Mugler, John P; Sá, Rui C; Altes, Talissa A; Prisk, G Kim; Hopkins, Susan R

    2014-12-01

    The field of proton lung MRI is advancing on a variety of fronts. In the realm of functional imaging, it is now possible to use arterial spin labeling (ASL) and oxygen-enhanced imaging techniques to quantify regional perfusion and ventilation, respectively, in standard units of measurement. By combining these techniques into a single scan, it is also possible to quantify the local ventilation-perfusion ratio, which is the most important determinant of gas-exchange efficiency in the lung. To demonstrate potential for accurate and meaningful measurements of lung function, this technique was used to study gravitational gradients of ventilation, perfusion, and ventilation-perfusion ratio in healthy subjects, yielding quantitative results consistent with expected regional variations. Such techniques can also be applied in the time domain, providing new tools for studying temporal dynamics of lung function. Temporal ASL measurements showed increased spatial-temporal heterogeneity of pulmonary blood flow in healthy subjects exposed to hypoxia, suggesting sensitivity to active control mechanisms such as hypoxic pulmonary vasoconstriction, and illustrating that to fully examine the factors that govern lung function it is necessary to consider temporal as well as spatial variability. Further development to increase spatial coverage and improve robustness would enhance the clinical applicability of these new functional imaging tools. In the realm of structural imaging, pulse sequence techniques such as ultrashort echo-time radial k-space acquisition, ultrafast steady-state free precession, and imaging-based diaphragm triggering can be combined to overcome the significant challenges associated with proton MRI in the lung, enabling high-quality three-dimensional imaging of the whole lung in a clinically reasonable scan time. Images of healthy and cystic fibrosis subjects using these techniques demonstrate substantial promise for non-contrast pulmonary angiography and detailed

  9. New developments of X-ray fluorescence imaging techniques in laboratory

    NASA Astrophysics Data System (ADS)

    Tsuji, Kouichi; Matsuno, Tsuyoshi; Takimoto, Yuki; Yamanashi, Masaki; Kometani, Noritsugu; Sasaki, Yuji C.; Hasegawa, Takeshi; Kato, Shuichi; Yamada, Takashi; Shoji, Takashi; Kawahara, Naoki

    2015-11-01

    X-ray fluorescence (XRF) analysis is a well-established analytical technique with a long research history. Many applications have been reported in various fields, such as in the environmental, archeological, biological, and forensic sciences as well as in industry. This is because XRF has a unique advantage of being a nondestructive analytical tool with good precision for quantitative analysis. Recent advances in XRF analysis have been realized by the development of new x-ray optics and x-ray detectors. Advanced x-ray focusing optics enables the making of a micro x-ray beam, leading to micro-XRF analysis and XRF imaging. A confocal micro-XRF technique has been applied for the visualization of elemental distributions inside the samples. This technique was applied for liquid samples and for monitoring chemical reactions such as the metal corrosion of steel samples in the NaCl solutions. In addition, a principal component analysis was applied for reducing the background intensity in XRF spectra obtained during XRF mapping, leading to improved spatial resolution of confocal micro-XRF images. In parallel, the authors have proposed a wavelength dispersive XRF (WD-XRF) imaging spectrometer for a fast elemental imaging. A new two dimensional x-ray detector, the Pilatus detector was applied for WD-XRF imaging. Fast XRF imaging in 1 s or even less was demonstrated for Euro coins and industrial samples. In this review paper, these recent advances in laboratory-based XRF imaging, especially in a laboratory setting, will be introduced.

  10. Challenges and recent advances in mass spectrometric imaging of neurotransmitters

    PubMed Central

    Gemperline, Erin; Chen, Bingming; Li, Lingjun

    2014-01-01

    Mass spectrometric imaging (MSI) is a powerful tool that grants the ability to investigate a broad mass range of molecules, from small molecules to large proteins, by creating detailed distribution maps of selected compounds. To date, MSI has demonstrated its versatility in the study of neurotransmitters and neuropeptides of different classes toward investigation of neurobiological functions and diseases. These studies have provided significant insight in neurobiology over the years and current technical advances are facilitating further improvements in this field. neurotransmitters, focusing specifically on the challenges and recent Herein, we advances of MSI of neurotransmitters. PMID:24568355

  11. 3D thermography imaging standardization technique for inflammation diagnosis

    NASA Astrophysics Data System (ADS)

    Ju, Xiangyang; Nebel, Jean-Christophe; Siebert, J. Paul

    2005-01-01

    We develop a 3D thermography imaging standardization technique to allow quantitative data analysis. Medical Digital Infrared Thermal Imaging is very sensitive and reliable mean of graphically mapping and display skin surface temperature. It allows doctors to visualise in colour and quantify temperature changes in skin surface. The spectrum of colours indicates both hot and cold responses which may co-exist if the pain associate with an inflammatory focus excites an increase in sympathetic activity. However, due to thermograph provides only qualitative diagnosis information, it has not gained acceptance in the medical and veterinary communities as a necessary or effective tool in inflammation and tumor detection. Here, our technique is based on the combination of visual 3D imaging technique and thermal imaging technique, which maps the 2D thermography images on to 3D anatomical model. Then we rectify the 3D thermogram into a view independent thermogram and conform it a standard shape template. The combination of these imaging facilities allows the generation of combined 3D and thermal data from which thermal signatures can be quantified.

  12. Rock type discrimination techniques using Landsat and Seasat image data

    NASA Technical Reports Server (NTRS)

    Blom, R.; Abrams, M.; Conrad, C.

    1981-01-01

    Results of a sedimentary rock type discrimination project using Seasat radar and Landsat multispectral image data of the San Rafael Swell, in eastern Utah, are presented, which has the goal of determining the potential contribution of radar image data to Landsat image data for rock type discrimination, particularly when the images are coregistered. The procedure employs several images processing techniques using the Landsat and Seasat data independently, and then both data sets are coregistered. The images are evaluated according to the ease with which contacts can be located and rock units (not just stratigraphically adjacent ones) separated. Results show that of the Landsat images evaluated, the image using a supervised classification scheme is the best for sedimentary rock type discrimination. Of less value, in decreasing order, are color ratio composites, principal components, and the standard color composite. In addition, for rock type discrimination, the black and white Seasat image is less useful than any of the Landsat color images by itself. However, it is found that the incorporation of the surface textural measures made from the Seasat image provides a considerable and worthwhile improvement in rock type discrimination.

  13. Techniques for Restoration and Enhancement of Solar Images

    NASA Astrophysics Data System (ADS)

    Karovska, Margarita

    1997-05-01

    Image restoration and enhancement techniques offer a powerful tool to extract information on the small-scale structure stored in the space- and ground-based solar observations. I will describe several deconvolution techniques that can be used to improve the resolution in the images. These include techniques that can be applied when the Point Spread Functions (PSFs) are well known, as well as techniques that allow both the high resolution information, and the degrading PSF to be recovered from a single high signal-to-noise image. I will also discuss several algorithms used to enhance low-contrast small-scale structures in the solar atmosphere, particularly when they are embedded in large bright structures, or located at or above the solar limb. Although strictly speaking these methods do not improve the resolution in the images, the enhancement of the fine structures allows detailed study of their spatial characteristics and temporal variability. Finally, I will demonstrate the potential of image post-processing for probing the fine scale and temporal variability of the solar atmosphere, by highlighting some recent examples resulting from the application of these techniques to a sample of Solar observations from the ground and from space.

  14. Advances in Magnetic Resonance Imaging Contrast Agents for Biomarker Detection

    PubMed Central

    Sinharay, Sanhita; Pagel, Mark D.

    2016-01-01

    Recent advances in magnetic resonance imaging (MRI) contrast agents have provided new capabilities for biomarker detection through molecular imaging. MRI contrast agents based on the T2 exchange mechanism have more recently expanded the armamentarium of agents for molecular imaging. Compared with T1 and T2* agents, T2 exchange agents have a slower chemical exchange rate, which improves the ability to design these MRI contrast agents with greater specificity for detecting the intended biomarker. MRI contrast agents that are detected through chemical exchange saturation transfer (CEST) have even slower chemical exchange rates. Another emerging class of MRI contrast agents uses hyperpolarized 13C to detect the agent with outstanding sensitivity. These hyperpolarized 13C agents can be used to track metabolism and monitor characteristics of the tissue microenvironment. Together, these various MRI contrast agents provide excellent opportunities to develop molecular imaging for biomarker detection. PMID:27049630

  15. Advances in Magnetic Resonance Imaging Contrast Agents for Biomarker Detection.

    PubMed

    Sinharay, Sanhita; Pagel, Mark D

    2016-06-12

    Recent advances in magnetic resonance imaging (MRI) contrast agents have provided new capabilities for biomarker detection through molecular imaging. MRI contrast agents based on the T2 exchange mechanism have more recently expanded the armamentarium of agents for molecular imaging. Compared with T1 and T2* agents, T2 exchange agents have a slower chemical exchange rate, which improves the ability to design these MRI contrast agents with greater specificity for detecting the intended biomarker. MRI contrast agents that are detected through chemical exchange saturation transfer (CEST) have even slower chemical exchange rates. Another emerging class of MRI contrast agents uses hyperpolarized (13)C to detect the agent with outstanding sensitivity. These hyperpolarized (13)C agents can be used to track metabolism and monitor characteristics of the tissue microenvironment. Together, these various MRI contrast agents provide excellent opportunities to develop molecular imaging for biomarker detection. PMID:27049630

  16. Advanced hyperspectral video imaging system using Amici prism.

    PubMed

    Feng, Jiao; Fang, Xiaojing; Cao, Xun; Ma, Chenguang; Dai, Qionghai; Zhu, Hongbo; Wang, Yongjin

    2014-08-11

    In this paper, we propose an advanced hyperspectral video imaging system (AHVIS), which consists of an objective lens, an occlusion mask, a relay lens, an Amici prism and two cameras. An RGB camera is used for spatial reading and a gray scale camera is used for measuring the scene with spectral information. The objective lens collects more light energy from the observed scene and images the scene on an occlusion mask, which subsamples the image of the observed scene. Then, the subsampled image is sent to the gray scale camera through the relay lens and the Amici prism. The Amici prism that is used to realize spectral dispersion along the optical path reduces optical distortions and offers direct view of the scene. The main advantages of the proposed system are improved light throughput and less optical distortion. Furthermore, the presented configuration is more compact, robust and practicable. PMID:25321019

  17. Advances in Magnetic Resonance Imaging Contrast Agents for Biomarker Detection

    NASA Astrophysics Data System (ADS)

    Sinharay, Sanhita; Pagel, Mark D.

    2016-06-01

    Recent advances in magnetic resonance imaging (MRI) contrast agents have provided new capabilities for biomarker detection through molecular imaging. MRI contrast agents based on the T2 exchange mechanism have more recently expanded the armamentarium of agents for molecular imaging. Compared with T1 and T2* agents, T2 exchange agents have a slower chemical exchange rate, which improves the ability to design these MRI contrast agents with greater specificity for detecting the intended biomarker. MRI contrast agents that are detected through chemical exchange saturation transfer (CEST) have even slower chemical exchange rates. Another emerging class of MRI contrast agents uses hyperpolarized 13C to detect the agent with outstanding sensitivity. These hyperpolarized 13C agents can be used to track metabolism and monitor characteristics of the tissue microenvironment. Together, these various MRI contrast agents provide excellent opportunities to develop molecular imaging for biomarker detection.

  18. Cylindrical millimeter-wave imaging technique for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    1998-03-01

    A novel cylindrical millimeter-wave imaging technique has been developed at the Pacific Northwest National Laboratory for the detection of metallic and non-metallic concealed weapons. This technique uses a vertical array of millimeter- wave antennas which is mechanically swept around a person in a cylindrical fashion. The wideband millimeter-wave data is mathematically reconstructed into a series of high- resolution images of the person being screened. Clothing is relatively transparent to millimeter-wave illumination,whereas the human body and concealed items are reflective at millimeter wavelengths. Differences in shape and reflectivity are revealed in the images and allow a human operator to detect and identify concealed weapons. A full 360 degree scan is necessary to fully inspect a person for concealed items. The millimeter-wave images can be formed into a video animation sequence in which the person appears to rotate in front of a fixed illumination source.This is s convenient method for presenting the 3D image data for analysis. This work has been fully sponsored by the FAA. An engineering prototype based on the cylindrical imaging technique is presently under development. The FAA is currently opposed to presenting the image data directly to the operator due to personal privacy concerns. A computer automated system is desired to address this problem by eliminating operator viewing of the imagery.

  19. Image measurement technique on vibration amplitude of ultrasonic horn

    NASA Astrophysics Data System (ADS)

    Zhang, Yong-bin; Wu, Zhi-qun; Zhu, Jian-ping; He, Jian-guo; Liu, Guang-min

    2013-10-01

    The paper proposes a method to measure vibration amplitude of ultrasonic horn which is a very important component in the spindle for micro-electrical-chemical discharging machining. The method of image measuring amplitude on high frequency vibration is introduced. Non-contact measurement system based on vision technology is constructed. High precision location algorithm on image centroid, quadratic location algorithm, is presented to find the center of little light spot. Measurement experiments have been done to show the effect of image measurement technique on vibration amplitude of ultrasonic horn. In the experiments, precise calibration of the vision system is implemented using a normal graticule to obtain the scale factor between image pixel and real distance. The vibration amplitude of ultrasonic horn is changed by modifying the voltage amplitude of pulse power supply. The image of feature on ultrasonic horn is captured and image processing is carried out. The vibration amplitudes are got at different voltages.

  20. Oncologic image compression using both wavelet and masking techniques.

    PubMed

    Yin, F F; Gao, Q

    1997-12-01

    A new algorithm has been developed to compress oncologic images using both wavelet transform and field masking methods. A compactly supported wavelet transform is used to decompose the original image into high- and low-frequency subband images. The region-of-interest (ROI) inside an image, such as an irradiated field in an electronic portal image, is identified using an image segmentation technique and is then used to generate a mask. The wavelet transform coefficients outside the mask region are then ignored so that these coefficients can be efficiently coded to minimize the image redundancy. In this study, an adaptive uniform scalar quantization method and Huffman coding with a fixed code book are employed in subsequent compression procedures. Three types of typical oncologic images are tested for compression using this new algorithm: CT, MRI, and electronic portal images with 256 x 256 matrix size and 8-bit gray levels. Peak signal-to-noise ratio (PSNR) is used to evaluate the quality of reconstructed image. Effects of masking and image quality on compression ratio are illustrated. Compression ratios obtained using wavelet transform with and without masking for the same PSNR are compared for all types of images. The addition of masking shows an increase of compression ratio by a factor of greater than 1.5. The effect of masking on the compression ratio depends on image type and anatomical site. A compression ratio of greater than 5 can be achieved for a lossless compression of various oncologic images with respect to the region inside the mask. Examples of reconstructed images with compression ratio greater than 50 are shown. PMID:9434988

  1. Deep-space satellite-image reconstructions from field data by use of speckle imaging techniques: images and functional assessment

    NASA Astrophysics Data System (ADS)

    Matson, Charles L.; Fox, Marsha; Hege, E. Keith; Hluck, Laura; Drummond, Jack; Harvey, David

    1997-05-01

    Speckle imaging techniques have been shown to mitigate atmospheric-resolution limits, allowing near-diffraction-limited images to be reconstructed. Few images of extended objects reconstructed by use of these techniques have been published, and most of these results are for relatively bright objects. We present image reconstructions of an orbiting Molniya 3 spacecraft from data collected by use of a 2.3-m ground-based telescope. The apparent brightness of the satellite was 15th visual magnitude. Power-spectrum and bispectrum speckle imaging techniques are used prior to image reconstruction to ameliorate atmospheric blurring. We discuss how these images, although poorly resolved, can be used to provide information on the satellite s functional status. It is shown that our previously published optimal algorithms produce a higher-quality image than do conventional speckle imaging methods.

  2. Video multiple watermarking technique based on image interlacing using DWT.

    PubMed

    Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

    2014-01-01

    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. PMID:25587570

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

    PubMed Central

    Ibrahim, Mohamed M.; Abdel Kader, Neamat S.; Zorkany, M.

    2014-01-01

    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. PMID:25587570

  4. Stellar Family Portrait Takes Imaging Technique to New Extremes

    NASA Astrophysics Data System (ADS)

    2009-12-01

    The young star cluster Trumpler 14 is revealed in another stunning ESO image. The amount of exquisite detail seen in this portrait, which beautifully reveals the life of a large family of stars, is due to the Multi-conjugate Adaptive optics Demonstrator (MAD) on ESO's Very Large Telescope. Never before has such a large patch of sky been imaged using adaptive optics [1], a technique by which astronomers are able to remove most of the atmosphere's blurring effects. Noted for harbouring Eta Carinae - one of the wildest and most massive stars in our galaxy - the impressive Carina Nebula also houses a handful of massive clusters of young stars. The youngest of these stellar families is the Trumpler 14 star cluster, which is less than one million years old - a blink of an eye in the Universe's history. This large open cluster is located some 8000 light-years away towards the constellation of Carina (the Keel). A team of astronomers, led by Hugues Sana, acquired astounding images of the central part of Trumpler 14 using the Multi-conjugate Adaptive optics Demonstrator (MAD, [2]) mounted on ESO's Very Large Telescope (VLT). Thanks to MAD, astronomers were able to remove most of the blurring effects of the atmosphere and thus obtain very sharp images. MAD performs this correction over a much larger patch of the sky than any other current adaptive optics instrument, allowing astronomers to make wider, crystal-clear images. Thanks to the high quality of the MAD images, the team of astronomers could obtain a very nice family portrait. They found that Trumpler 14 is not only the youngest - with a refined, newly estimated age of just 500 000 years - but also one of the most populous star clusters within the nebula. The astronomers counted about 2000 stars in their image, spanning the whole range from less than one tenth up to a factor of several tens of times the mass of our own Sun. And this in a region which is only about six light-years across, that is, less than twice the

  5. White Paper AGA: Advanced Imaging in Barrett's Esophagus.

    PubMed

    Sharma, Prateek; Brill, Joel; Canto, Marcia; DeMarco, Daniel; Fennerty, Brian; Gupta, Neil; Laine, Loren; Lieberman, David; Lightdale, Charles; Montgomery, Elizabeth; Odze, Robert; Tokar, Jeffrey; Kochman, Michael

    2015-12-01

    Enhanced imaging technologies such as narrow band imaging, flexible spectral imaging color enhancement, i-Scan, confocal laser endomicroscopy, and optical coherence tomography are readily available for use by endoscopists in routine clinical practice. In November 2014, the American Gastroenterological Association's Center for GI Innovation and Technology conducted a 2-day workshop to discuss endoscopic image enhancement technologies, focusing on their role in 2 specific clinical conditions (colon polyps and Barrett's esophagus) and on issues relating to training and implementation of these technologies (white papers). Although the majority of the studies that use enhanced imaging technologies have been positive, these techniques ideally need to be validated in larger cohorts and in community centers. As it stands today, detailed endoscopic examination with high-definition white-light endoscopy and random 4-quadrant biopsy remains the standard of care. However, the workshop panelists agreed that in the hands of endoscopists who have met the preservation and incorporation of valuable endoscopic innovation thresholds (diagnostic accuracy) with enhanced imaging techniques (specific technologies), use of the technique in Barrett's esophagus patients is appropriate. PMID:26462567

  6. Optical design and characterization of an advanced computational imaging system

    NASA Astrophysics Data System (ADS)

    Shepard, R. Hamilton; Fernandez-Cull, Christy; Raskar, Ramesh; Shi, Boxin; Barsi, Christopher; Zhao, Hang

    2014-09-01

    We describe an advanced computational imaging system with an optical architecture that enables simultaneous and dynamic pupil-plane and image-plane coding accommodating several task-specific applications. We assess the optical requirement trades associated with custom and commercial-off-the-shelf (COTS) optics and converge on the development of two low-cost and robust COTS testbeds. The first is a coded-aperture programmable pixel imager employing a digital micromirror device (DMD) for image plane per-pixel oversampling and spatial super-resolution experiments. The second is a simultaneous pupil-encoded and time-encoded imager employing a DMD for pupil apodization or a deformable mirror for wavefront coding experiments. These two testbeds are built to leverage two MIT Lincoln Laboratory focal plane arrays - an orthogonal transfer CCD with non-uniform pixel sampling and on-chip dithering and a digital readout integrated circuit (DROIC) with advanced on-chip per-pixel processing capabilities. This paper discusses the derivation of optical component requirements, optical design metrics, and performance analyses for the two testbeds built.

  7. Advanced biologically plausible algorithms for low-level image processing

    NASA Astrophysics Data System (ADS)

    Gusakova, Valentina I.; Podladchikova, Lubov N.; Shaposhnikov, Dmitry G.; Markin, Sergey N.; Golovan, Alexander V.; Lee, Seong-Whan

    1999-08-01

    At present, in computer vision, the approach based on modeling the biological vision mechanisms is extensively developed. However, up to now, real world image processing has no effective solution in frameworks of both biologically inspired and conventional approaches. Evidently, new algorithms and system architectures based on advanced biological motivation should be developed for solution of computational problems related to this visual task. Basic problems that should be solved for creation of effective artificial visual system to process real world imags are a search for new algorithms of low-level image processing that, in a great extent, determine system performance. In the present paper, the result of psychophysical experiments and several advanced biologically motivated algorithms for low-level processing are presented. These algorithms are based on local space-variant filter, context encoding visual information presented in the center of input window, and automatic detection of perceptually important image fragments. The core of latter algorithm are using local feature conjunctions such as noncolinear oriented segment and composite feature map formation. Developed algorithms were integrated into foveal active vision model, the MARR. It is supposed that proposed algorithms may significantly improve model performance while real world image processing during memorizing, search, and recognition.

  8. Three-dimensional electron paramagnetic resonance imaging technique for mapping porosity in ceramics

    SciTech Connect

    Kordas, G.; Kang, Y.H. )

    1991-04-01

    This paper reports on a three-dimensional (3D) electron paramagnetic resonance imaging (EPRI) method which was developed to probe the structure and size of pores in ceramic materials. The imaging device that was added to the EPR instrument consisted of a computer-controlled current source and magnetic field gradient. This add-on facility was tested using a well-defined diphenlpicrylhydrazzyl phantom sample. Pumice was then used to demonstrate the potential of the technique. This stone was immersed in a 0.5 mm {sup 15}N-substituted per-deutereted tempone water solution to fill the pores with spin labels. Images were reconstructed using a filtered back-projection technique. A two-dimensional (2D) imaging plane was constructed by collecting 33 projection planes over 180 {degrees}. A 3D image was derived from 22 planes each constructed by 22 projections. At present, the facility allows a resolution of 69 and 46 {mu}m for 2D and 3D imaging, respectively. Advancements of the imaging apparatus, software, and line width of the spin labels will be needed to enhance the resolution of this technique.

  9. Improving face image extraction by using deep learning technique

    NASA Astrophysics Data System (ADS)

    Xue, Zhiyun; Antani, Sameer; Long, L. R.; Demner-Fushman, Dina; Thoma, George R.

    2016-03-01

    The National Library of Medicine (NLM) has made a collection of over a 1.2 million research articles containing 3.2 million figure images searchable using the Open-iSM multimodal (text+image) search engine. Many images are visible light photographs, some of which are images containing faces ("face images"). Some of these face images are acquired in unconstrained settings, while others are studio photos. To extract the face regions in the images, we first applied one of the most widely-used face detectors, a pre-trained Viola-Jones detector implemented in Matlab and OpenCV. The Viola-Jones detector was trained for unconstrained face image detection, but the results for the NLM database included many false positives, which resulted in a very low precision. To improve this performance, we applied a deep learning technique, which reduced the number of false positives and as a result, the detection precision was improved significantly. (For example, the classification accuracy for identifying whether the face regions output by this Viola- Jones detector are true positives or not in a test set is about 96%.) By combining these two techniques (Viola-Jones and deep learning) we were able to increase the system precision considerably, while avoiding the need to manually construct a large training set by manual delineation of the face regions.

  10. Application of optical correlation techniques to particle imaging velocimetry

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.; Edwards, Robert V.

    1988-01-01

    Pulsed laser sheet velocimetry yields nonintrusive measurements of velocity vectors across an extended 2-dimensional region of the flow field. The application of optical correlation techniques to the analysis of multiple exposure laser light sheet photographs can reduce and/or simplify the data reduction time and hardware. Here, Matched Spatial Filters (MSF) are used in a pattern recognition system. Usually MSFs are used to identify the assembly line parts. In this application, the MSFs are used to identify the iso-velocity vector contours in the flow. The patterns to be recognized are the recorded particle images in a pulsed laser light sheet photograph. Measurement of the direction of the partical image displacements between exposures yields the velocity vector. The particle image exposure sequence is designed such that the velocity vector direction is determined unambiguously. A global analysis technique is used in comparison to the more common particle tracking algorithms and Young's fringe analysis technique.

  11. Application of optical correlation techniques to particle imaging

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.; Edwards, Robert V.

    1988-01-01

    Pulsed laser sheet velocimetry yields noninstrusive measurements of velocity vectors across an extended 2-dimensional region of the flow field. The application of optical correlation techniques to the analysis of multiple exposure laser light sheet photographs can reduce and/or simplify the data reduction time and hardware. Here, Matched Spatial Filters (MSF) are used in a pattern recognition system. Usuallay MSFs are used to identify the assembly line parts. In this application, the MSFs are used to identify the iso-velocity vector contours in the flow. The patterns to be recognized are the recorded particle images in a pulsed laser light sheet photograph. Measurement of the direction of the particle image displacements between exposures yields the velocity vector. The particle image exposure sequence is designed such that the velocity vector direction is determined unambiguously. A global analysis technique is used in comparison to the more common particle tracking algorithms and Young's fringe analysis technique.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Defect Imaging Technique Using a Scanning Laser Source

    NASA Astrophysics Data System (ADS)

    Hayashi, T.; Murase, M.; Kitayama, T.

    2011-06-01

    Considering the applications to in-line testing of products, water-free imaging technique is required. This study described defect imaging technique using a scanning laser source. Laser beam was emitted onto a surface of a plate, and then guided waves excited at the laser source were detected by ultrasonic transducers fixed on the plate surface. For a plate with rounded defects, amplitude distributions obtained by scanning the laser source corresponded to thickness distributions, but for plates with rectangular notches, unwanted artifacts were seen due to reflection, diffraction, and ultrasonic attenuation. Then, using multiple receiving transducers and synthesizing multiple images, distinct defect images were obtained for a flat plate and a curved plate with rectangular notches.

  14. Laser Illumination Modality of Photoacoustic Imaging Technique for Prostate Cancer

    NASA Astrophysics Data System (ADS)

    Peng, Dong-qing; Peng, Yuan-yuan; Guo, Jian; Li, Hui

    2016-02-01

    Photoacoustic imaging (PAI) has recently emerged as a promising imaging technique for prostate cancer. But there was still a lot of challenge in the PAI for prostate cancer detection, such as laser illumination modality. Knowledge of absorbed light distribution in prostate tissue was essential since the distribution characteristic of absorbed light energy would influence the imaging depth and range of PAI. In order to make a comparison of different laser illumination modality of photoacoustic imaging technique for prostate cancer, optical model of human prostate was established and combined with Monte Carlo simulation method to calculate the light absorption distribution in the prostate tissue. Characteristic of light absorption distribution of transurethral and trans-rectal illumination case, and of tumor at different location was compared with each other.The relevant conclusions would be significant for optimizing the light illumination in a PAI system for prostate cancer detection.

  15. A High Performance Image Data Compression Technique for Space Applications

    NASA Technical Reports Server (NTRS)

    Yeh, Pen-Shu; Venbrux, Jack

    2003-01-01

    A highly performing image data compression technique is currently being developed for space science applications under the requirement of high-speed and pushbroom scanning. The technique is also applicable to frame based imaging data. The algorithm combines a two-dimensional transform with a bitplane encoding; this results in an embedded bit string with exact desirable compression rate specified by the user. The compression scheme performs well on a suite of test images acquired from spacecraft instruments. It can also be applied to three-dimensional data cube resulting from hyper-spectral imaging instrument. Flight qualifiable hardware implementations are in development. The implementation is being designed to compress data in excess of 20 Msampledsec and support quantization from 2 to 16 bits. This paper presents the algorithm, its applications and status of development.

  16. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    PubMed Central

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors. PMID:12587031

  17. Biotechnology apprenticeship for secondary-level students: teaching advanced cell culture techniques for research.

    PubMed

    Lewis, Jennifer R; Kotur, Mark S; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A; Ferrell, Nick; Sullivan, Kathryn D; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors. PMID:12587031

  18. Advanced Imaging for Biopsy Guidance in Primary Brain Tumors

    PubMed Central

    Tsiouris, Apostolos J; Ramakrishna, Rohan

    2016-01-01

    Accurate glioma sampling is required for diagnosis and establishing eligibility for relevant clinical trials. MR-based perfusion and spectroscopy sequences supplement conventional MR in noninvasively predicting the areas of highest tumor grade for biopsy. We report the case of a patient with gliomatosis cerebri and multifocal patchy enhancement in whom the combination of advanced and conventional imaging attributes successfully guided a diagnostic biopsy. PMID:27014538

  19. Advanced indium antimonide monolithic charge coupled infrared imaging arrays

    NASA Technical Reports Server (NTRS)

    Koch, T. L.; Merilainen, C. A.; Thom, R. D.

    1981-01-01

    The continued process development of SiO2 insulators for use in advanced InSb monolithic charge coupled infrared imaging arrays is described. Specific investigations into the use of plasma enhanced chemical vapor deposited (PECVD) SiO2 as a gate insulator for InSb charge coupled devices is discussed, as are investigations of other chemical vapor deposited SiO2 materials.

  20. Recent Advances in Image-Guided Radiotherapy for Head and Neck Carcinoma

    PubMed Central

    Nath, Sameer K.; Simpson, Daniel R.; Rose, Brent S.; Sandhu, Ajay P.

    2009-01-01

    Radiotherapy has a well-established role in the management of head and neck cancers. Over the past decade, a variety of new imaging modalities have been incorporated into the radiotherapy planning and delivery process. These technologies are collectively referred to as image-guided radiotherapy and may lead to significant gains in tumor control and radiation side effect profiles. In the following review, these techniques as they are applied to head and neck cancer patients are described, and clinical studies analyzing their use in target delineation, patient positioning, and adaptive radiotherapy are highlighted. Finally, we conclude with a brief discussion of potential areas of further radiotherapy advancement. PMID:19644564

  1. Advances in the reconstruction of LBT LINC-NIRVANA images

    NASA Astrophysics Data System (ADS)

    La Camera, A.; Desiderá, G.; Arcidiacono, C.; Boccacci, P.; Bertero, M.

    2007-09-01

    Context: LINC-NIRVANA, the Fizeau interferometer of the Large Binocular Telescope (LBT), will require routine use of image reconstruction methods for data reduction. To this purpose our group has already developed the software package AIRY (Astronomical Image Restoration in interferometrY). Aims: Observations of a target, with different orientations of the baseline of LINC-NIRVANA, will provide images with different orientations with respect to the CCD camera. This rotation effect was not taken into account in our previous work. Therefore in this paper we propose a method able to compensate for the rotation of the field of view. Moreover we investigate acceleration techniques for reducing the computational burden of multiple image deconvolution. Methods: The basic method is a suitable modification of the Richardson-Lucy algorithm, also implementing an approach we proposed for reducing boundary effects. Acceleration techniques, proposed by Biggs & Andrews, are extended and applied to this new algorithm. Finally a method for estimating the unknown point spread function (PSF) by extracting and extrapolating the image of a reference star is developed and implemented. Results: The method introduced for compensating object rotation and reducing boundary effects, as well as its accelerated versions, are tested on simulated LINC-NIRVANA images, using the VLT image of the Crab Nebula as test object. The results are very promising. Moreover the method for PSFs extraction is tested on simulated images, derived from the LBT image of the galaxy NGC 6946 and obtained by convolving this image with PSFs computed by means of the numerical code LOST (Layer Oriented Simulation Tool).

  2. Recent Advances in CT and MR Imaging for Evaluation of Hepatocellular Carcinoma

    PubMed Central

    Lee, Jeong Min; Yoon, Jeong-Hee; Joo, Ijin; Woo, Hyun Sik

    2012-01-01

    Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Accurate diagnosis and assessment of disease extent are crucial for proper management of patients with HCC. Imaging plays a crucial role in early detection, accurate staging, and the planning of management strategies. A variety of imaging modalities are currently used in evaluating patients with suspected HCC; these include ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, and angiography. Among these modalities, dynamic MRI and CT are regarded as the best imaging techniques available for the noninvasive diagnosis of HCC. Recent improvements in CT and MRI technology have made noninvasive and reliable diagnostic assessment of hepatocellular nodules possible in the cirrhotic liver, and biopsy is frequently not required prior to treatment. Until now, the major challenge for radiologists in imaging cirrhosis has been the characterization of small cirrhotic nodules smaller than 2 cm in diameter. Further technological advancement will undoubtedly have a major impact on liver tumor imaging. The increased speed of data acquisition in CT and MRI has allowed improvements in both spatial and temporal resolution, which have made possible a more precise evaluation of the hemodynamics of liver nodules. Furthermore, the development of new, tissue-specific contrast agents such as gadoxetic acid has improved HCC detection on MRI. In this review, we discuss the role of CT and MRI in the diagnosis and staging of HCC, recent technological advances, and the strengths and limitations of these imaging modalities. PMID:24159569

  3. A novel data processing technique for image reconstruction of penumbral imaging

    NASA Astrophysics Data System (ADS)

    Xie, Hongwei; Li, Hongyun; Xu, Zeping; Song, Guzhou; Zhang, Faqiang; Zhou, Lin

    2011-06-01

    CT image reconstruction technique was applied to the data processing of the penumbral imaging. Compared with other traditional processing techniques for penumbral coded pinhole image such as Wiener, Lucy-Richardson and blind technique, this approach is brand new. In this method, the coded aperture processing method was used for the first time independent to the point spread function of the image diagnostic system. In this way, the technical obstacles was overcome in the traditional coded pinhole image processing caused by the uncertainty of point spread function of the image diagnostic system. Then based on the theoretical study, the simulation of penumbral imaging and image reconstruction was carried out to provide fairly good results. While in the visible light experiment, the point source of light was used to irradiate a 5mm×5mm object after diffuse scattering and volume scattering. The penumbral imaging was made with aperture size of ~20mm. Finally, the CT image reconstruction technique was used for image reconstruction to provide a fairly good reconstruction result.

  4. Digital image correlation techniques applied to LANDSAT multispectral imagery

    NASA Technical Reports Server (NTRS)

    Bonrud, L. O. (Principal Investigator); Miller, W. J.

    1976-01-01

    The author has identified the following significant results. Automatic image registration and resampling techniques applied to LANDSAT data achieved accuracies, resulting in mean radial displacement errors of less than 0.2 pixel. The process method utilized recursive computational techniques and line-by-line updating on the basis of feedback error signals. Goodness of local feature matching was evaluated through the implementation of a correlation algorithm. An automatic restart allowed the system to derive control point coordinates over a portion of the image and to restart the process, utilizing this new control point information as initial estimates.

  5. Fingerprint pattern restoration by digital image processing techniques.

    PubMed

    Wen, Che-Yen; Yu, Chiu-Chung

    2003-09-01

    Fingerprint evidence plays an important role in solving criminal problems. However, defective (lacking information needed for completeness) or contaminated (undesirable information included) fingerprint patterns make identifying and recognizing processes difficult. Unfortunately. this is the usual case. In the recognizing process (enhancement of patterns, or elimination of "false alarms" so that a fingerprint pattern can be searched in the Automated Fingerprint Identification System (AFIS)), chemical and physical techniques have been proposed to improve pattern legibility. In the identifying process, a fingerprint examiner can enhance contaminated (but not defective) fingerprint patterns under guidelines provided by the Scientific Working Group on Friction Ridge Analysis, Study and Technology (SWGFAST), the Scientific Working Group on Imaging Technology (SWGIT), and an AFIS working group within the National Institute of Justice. Recently, the image processing techniques have been successfully applied in forensic science. For example, we have applied image enhancement methods to improve the legibility of digital images such as fingerprints and vehicle plate numbers. In this paper, we propose a novel digital image restoration technique based on the AM (amplitude modulation)-FM (frequency modulation) reaction-diffusion method to restore defective or contaminated fingerprint patterns. This method shows its potential application to fingerprint pattern enhancement in the recognizing process (but not for the identifying process). Synthetic and real images are used to show the capability of the proposed method. The results of enhancing fingerprint patterns by the manual process and our method are evaluated and compared. PMID:14535661

  6. Individual Particle Analysis of Ambient PM 2.5 Using Advanced Electron Microscopy Techniques

    SciTech Connect

    Gerald J. Keeler; Masako Morishita

    2006-12-31

    The overall goal of this project was to demonstrate a combination of advanced electron microscopy techniques that can be effectively used to identify and characterize individual particles and their sources. Specific techniques to be used include high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM energy dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM). A series of ambient PM{sub 2.5} samples were collected in communities in southwestern Detroit, MI (close to multiple combustion sources) and Steubenville, OH (close to several coal fired utility boilers). High-resolution TEM (HRTEM) -imaging showed a series of nano-metal particles including transition metals and elemental composition of individual particles in detail. Submicron and nano-particles with Al, Fe, Ti, Ca, U, V, Cr, Si, Ba, Mn, Ni, K and S were observed and characterized from the samples. Among the identified nano-particles, combinations of Al, Fe, Si, Ca and Ti nano-particles embedded in carbonaceous particles were observed most frequently. These particles showed very similar characteristics of ultrafine coal fly ash particles that were previously reported. By utilizing HAADF-STEM, STEM-EDX, and EF-TEM, this investigation was able to gain information on the size, morphology, structure, and elemental composition of individual nano-particles collected in Detroit and Steubenville. The results showed that the contributions of local combustion sources - including coal fired utilities - to ultrafine particle levels were significant. Although this combination of advanced electron microscopy techniques by itself can not identify source categories, these techniques can be utilized as complementary analytical tools that are capable of providing detailed information on individual particles.

  7. Combined Photoacoustic-Acoustic Technique for Crack Imaging

    NASA Astrophysics Data System (ADS)

    Zakrzewski, J.; Chigarev, N.; Tournat, V.; Gusev, V.

    2010-01-01

    Nonlinear imaging of a crack by combination of a common photoacoustic imaging technique with additional acoustic loading has been performed. Acoustic signals at two different fundamental frequencies were launched in the sample, one photoacoustically through heating of the sample surface by the intensity-modulated scanning laser beam and another by a piezoelectrical transducer. The acoustic signal at mixed frequencies, generated due to system nonlinearity, has been detected by an accelerometer. Different physical mechanisms of the nonlinearity contributing to the contrast in linear and nonlinear photoacoustic imaging of the crack are discussed.

  8. Image reconstruction techniques applied to nuclear mass models

    NASA Astrophysics Data System (ADS)

    Morales, Irving O.; Isacker, P. Van; Velazquez, V.; Barea, J.; Mendoza-Temis, J.; Vieyra, J. C. López; Hirsch, J. G.; Frank, A.

    2010-02-01

    A new procedure is presented that combines well-known nuclear models with image reconstruction techniques. A color-coded image is built by taking the differences between measured masses and the predictions given by the different theoretical models. This image is viewed as part of a larger array in the (N,Z) plane, where unknown nuclear masses are hidden, covered by a “mask.” We apply a suitably adapted deconvolution algorithm, used in astronomical observations, to “open the window” and see the rest of the pattern. We show that it is possible to improve significantly mass predictions in regions not too far from measured nuclear masses.

  9. Recent advances in sample preparation techniques for effective bioanalytical methods.

    PubMed

    Kole, Prashant Laxman; Venkatesh, Gantala; Kotecha, Jignesh; Sheshala, Ravi

    2011-01-01

    This paper reviews the recent developments in bioanalysis sample preparation techniques and gives an update on basic principles, theory, applications and possibilities for automation, and a comparative discussion on the advantages and limitation of each technique. Conventional liquid-liquid extraction (LLE), protein precipitation (PP) and solid-phase extraction (SPE) techniques are now been considered as methods of the past. The last decade has witnessed a rapid development of novel sample preparation techniques in bioanalysis. Developments in SPE techniques such as selective sorbents and in the overall approach to SPE, such as hybrid SPE and molecularly imprinted polymer SPE, have been addressed. Considerable literature has been published in the area of solid-phase micro-extraction and its different versions, e.g. stir bar sorptive extraction, and their application in the development of selective and sensitive bioanalytical methods. Techniques such as dispersive solid-phase extraction, disposable pipette extraction and micro-extraction by packed sorbent offer a variety of extraction phases and provide unique advantages to bioanalytical methods. On-line SPE utilizing column-switching techniques is rapidly gaining acceptance in bioanalytical applications. PP sample preparation techniques such as PP filter plates/tubes offer many advantages like removal of phospholipids and proteins in plasma/serum. Newer approaches to conventional LLE techniques (salting-out LLE) are also covered in this review article. PMID:21154887

  10. Advances in photographic X-ray imaging for solar astronomy

    NASA Technical Reports Server (NTRS)

    Moses, J. Daniel; Schueller, R.; Waljeski, K.; Davis, John M.

    1989-01-01

    The technique of obtaining quantitative data from high resolution soft X-ray photographic images produced by grazing incidence optics was successfully developed to a high degree during the Solar Research Sounding Rocket Program and the S-054 X-Ray Spectrographic Telescope Experiment Program on Skylab. Continued use of soft X-ray photographic imaging in sounding rocket flights of the High Resolution Solar Soft X-Ray Imaging Payload has provided opportunities to further develop these techniques. The developments discussed include: (1) The calibration and use of an inexpensive, commercially available microprocessor controlled drum type film processor for photometric film development; (2) The use of Kodak Technical Pan 2415 film and Kodak SO-253 High Speed Holographic film for improved resolution; and (3) The application of a technique described by Cook, Ewing, and Sutton for determining the film characteristics curves from density histograms of the flight film. Although the superior sensitivity, noise level, and linearity of microchannel plate and CCD detectors attracts the development efforts of many groups working in soft X-ray imaging, the high spatial resolution and dynamic range as well as the reliability and ease of application of photographic media assures the continued use of these techniques in solar X-ray astronomy observations.

  11. Advances in photographic X-ray imaging for solar astronomy

    NASA Technical Reports Server (NTRS)

    Moses, D.; Schueller, R.; Waljeski, K.; Davis, J. M.

    1989-01-01

    The technique of obtaining quantitative data from high resolution soft X-ray photographic images produced by grazing incidence optics was successfully developed to a high degree during the AS&E Solar Research Sounding Rocket Program and the S-054 X-Ray Spectrographic Telescope Experiment Program on Skylab. Continued use of soft X-Ray photographic imaging in sounding rocket flights of the AS&E High Resolution Solar Soft X-Ray Imaging Payload has provided opportunities to further develop these techniques. The developments discussed include: (1) the calibration and use of an inexpensive, commercially available microprocessor controlled drum type film processor for photometric film development, (2) the use of Kodak Technical Pan 2415 film and Kodak SO-253 High Speed Holographic film for improved resolution, and (3) the application of a technique described by Cook, Ewing, and Sutton (1988) for determining the film characteristics curves from density histograms of the flight film. Although the superior sensitivity, noise level, and linearity of microchannel plate and CCD detectors attracts the development efforts of many groups working in soft X-ray imaging, the high spatial resolution and dynamic range as well as the reliability and ease of application of photographic media assures the continued use of these techniques in solar X-ray astronomy observations.

  12. Vegetation change detection based on image fusion technique

    NASA Astrophysics Data System (ADS)

    Jia, Yonghong; Liu, Yueyan; Yu, Hui; Li, Deren

    2005-10-01

    The change detection of land use and land cover has always been the focus of remotely sensed study and application. Based on techniques of image fusion, a new approach of detecting vegetation change according to vector of brightness index (BI) and perpendicular vegetation index (PVI) extracted from multi-temporal remotely sensed imagery is proposed. The procedure is introduced. Firstly, the Landsat eTM+ imagery is geometrically corrected and registered. Secondly, band 2,3,4 and panchromatic images of Landsat eTM+ are fused by a trous wavelet fusion, and bands 1,2,3 of SPOT are registered to the fused images. Thirdly, brightness index and perpendicular vegetation index are respectively extracted from SPOT images and fused images. Finally, change vectors are obtained and used to detect vegetation change. The testing results show that the approach of detecting vegetation change is very efficient.

  13. Optical and digital microscopic imaging techniques and applications in pathology.

    PubMed

    Chen, Xiaodong; Zheng, Bin; Liu, Hong

    2011-01-01

    The conventional optical microscope has been the primary tool in assisting pathological examinations. The modern digital pathology combines the power of microscopy, electronic detection, and computerized analysis. It enables cellular-, molecular-, and genetic-imaging at high efficiency and accuracy to facilitate clinical screening and diagnosis. This paper first reviews the fundamental concepts of microscopic imaging and introduces the technical features and associated clinical applications of optical microscopes, electron microscopes, scanning tunnel microscopes, and fluorescence microscopes. The interface of microscopy with digital image acquisition methods is discussed. The recent developments and future perspectives of contemporary microscopic imaging techniques such as three-dimensional and in vivo imaging are analyzed for their clinical potentials. PMID:21483100

  14. Image enhancement techniques applied to solar feature detection

    NASA Astrophysics Data System (ADS)

    Kowalski, Artur J.

    This dissertation presents the development of automatic image enhancement techniques for solar feature detection. The new method allows for detection and tracking of the evolution of filaments in solar images. Series of H-alpha full-disk images are taken in regular time intervals to observe the changes of the solar disk features. In each picture, the solar chromosphere filaments are identified for further evolution examination. The initial preprocessing step involves local thresholding to convert grayscale images into black-and-white pictures with chromosphere granularity enhanced. An alternative preprocessing method, based on image normalization and global thresholding is presented. The next step employs morphological closing operations with multi-directional linear structuring elements to extract elongated shapes in the image. After logical union of directional filtering results, the remaining noise is removed from the final outcome using morphological dilation and erosion with a circular structuring element. Experimental results show that the developed techniques can achieve excellent results in detecting large filaments and good detection rates for small filaments. The final chapter discusses proposed directions of the future research and applications to other areas of solar image processing, in particular to detection of solar flares, plages and sunspots.

  15. Modern Micro and Nanoparticle-Based Imaging Techniques

    PubMed Central

    Ryvolova, Marketa; Chomoucka, Jana; Drbohlavova, Jana; Kopel, Pavel; Babula, Petr; Hynek, David; Adam, Vojtech; Eckschlager, Tomas; Hubalek, Jaromir; Stiborova, Marie; Kaiser, Jozef; Kizek, Rene

    2012-01-01

    The requirements for early diagnostics as well as effective treatment of insidious diseases such as cancer constantly increase the pressure on development of efficient and reliable methods for targeted drug/gene delivery as well as imaging of the treatment success/failure. One of the most recent approaches covering both the drug delivery as well as the imaging aspects is benefitting from the unique properties of nanomaterials. Therefore a new field called nanomedicine is attracting continuously growing attention. Nanoparticles, including fluorescent semiconductor nanocrystals (quantum dots) and magnetic nanoparticles, have proven their excellent properties for in vivo imaging techniques in a number of modalities such as magnetic resonance and fluorescence imaging, respectively. In this article, we review the main properties and applications of nanoparticles in various in vitro imaging techniques, including microscopy and/or laser breakdown spectroscopy and in vivo methods such as magnetic resonance imaging and/or fluorescence-based imaging. Moreover the advantages of the drug delivery performed by nanocarriers such as iron oxides, gold, biodegradable polymers, dendrimers, lipid based carriers such as liposomes or micelles are also highlighted. PMID:23202187

  16. Nested image steganography scheme using QR-barcode technique

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Yuan; Wang, Jing-Wein

    2009-05-01

    In this paper, QR bar code and image processing techniques are used to construct a nested steganography scheme. There are two types of secret data (lossless and lossy) embedded into a cover image. The lossless data is text that is first encoded by the QR barcode; its data does not have any distortion when comparing with the extracted data and original data. The lossy data is a kind of image; the face image is suitable for our case. Because the extracted text is lossless, the error correction rate of QR encoding must be carefully designed. We found a 25% error correction rate is suitable for our goal. In image embedding, because it can sustain minor perceptible distortion, we thus adopted the lower nibble byte discard of the face image to reduce the secret data. When the image is extracted, we use a median filter to filter out the noise and obtain a smoother image quality. After simulation, it is evident that our scheme is robust to JPEG attacks. Compared to other steganography schemes, our proposed method has three advantages: (i) the nested scheme is an enhanced security system never previously developed; (ii) our scheme can conceal lossless and lossy secret data into a cover image simultaneously; and (iii) the QR barcode used as secret data can widely extend this method's application fields.

  17. Achieving molecular selectivity in imaging using multiphoton Raman spectroscopy techniques

    SciTech Connect

    Holtom, Gary R. ); Thrall, Brian D. ); Chin, Beek Yoke ); Wiley, H Steven ); Colson, Steven D. )

    2000-12-01

    In the case of most imaging methods, contrast is generated either by physical properties of the sample (Differential Image Contrast, Phase Contrast), or by fluorescent labels that are localized to a particular protein or organelle. Standard Raman and infrared methods for obtaining images are based upon the intrinsic vibrational properties of molecules, and thus obviate the need for attached flurophores. Unfortunately, they have significant limitations for live-cell imaging. However, an active Raman method, called Coherent Anti-Stokes Raman Scattering (CARS), is well suited for microscopy, and provides a new means for imaging specific molecules. Vibrational imaging techniques, such as CARS, avoid problems associated with photobleaching and photo-induced toxicity often associated with the use of fluorescent labels with live cells. Because the laser configuration needed to implement CARS technology is similar to that used in other multiphoton microscopy methods, such as two -photon fluorescence and harmonic generation, it is possible to combine imaging modalities, thus generating simultaneous CARS and fluorescence images. A particularly powerful aspect of CARS microscopy is its ability to selectively image deuterated compounds, thus allowing the visualization of molecules, such as lipids, that are chemically indistinguishable from the native species.

  18. Magneto-optical imaging technique for hostile environments: The ghost imaging approach

    NASA Astrophysics Data System (ADS)

    Meda, A.; Caprile, A.; Avella, A.; Ruo Berchera, I.; Degiovanni, I. P.; Magni, A.; Genovese, M.

    2015-06-01

    In this paper, we develop an approach to magneto optical imaging (MOI), applying a ghost imaging (GI) protocol to perform Faraday microscopy. MOI is of the utmost importance for the investigation of magnetic properties of material samples, through Weiss domains shape, dimension and dynamics analysis. Nevertheless, in some extreme conditions such as cryogenic temperatures or high magnetic field applications, there exists a lack of domain images due to the difficulty in creating an efficient imaging system in such environments. Here, we present an innovative MOI technique that separates the imaging optical path from the one illuminating the object. The technique is based on thermal light GI and exploits correlations between light beams to retrieve the image of magnetic domains. As a proof of principle, the proposed technique is applied to the Faraday magneto-optical observation of the remanence domain structure of an yttrium iron garnet sample.

  19. Magneto-optical imaging technique for hostile environments: The ghost imaging approach

    SciTech Connect

    Meda, A.; Caprile, A.; Avella, A.; Ruo Berchera, I.; Degiovanni, I. P.; Magni, A.; Genovese, M.

    2015-06-29

    In this paper, we develop an approach to magneto optical imaging (MOI), applying a ghost imaging (GI) protocol to perform Faraday microscopy. MOI is of the utmost importance for the investigation of magnetic properties of material samples, through Weiss domains shape, dimension and dynamics analysis. Nevertheless, in some extreme conditions such as cryogenic temperatures or high magnetic field applications, there exists a lack of domain images due to the difficulty in creating an efficient imaging system in such environments. Here, we present an innovative MOI technique that separates the imaging optical path from the one illuminating the object. The technique is based on thermal light GI and exploits correlations between light beams to retrieve the image of magnetic domains. As a proof of principle, the proposed technique is applied to the Faraday magneto-optical observation of the remanence domain structure of an yttrium iron garnet sample.

  20. Advances in MR Imaging for Cervical Spondylotic Myelopathy

    PubMed Central

    Ellingson, Benjamin M.; Salamon, Noriko; Holly, Langston T.

    2016-01-01

    Cervical spondylosis is the most common cause of nontraumatic spinal cord injury and is the most common cause of spinal cord dysfunction in the elderly. Magnetic resonance imaging (MRI) is an invaluable tool for the diagnosis and assessment of cervical spondylosis due to its sensitivity to soft tissues; however, standard MR techniques have some limitations in predicting neurological impairment and response to intervention. Therefore, there is great interest in novel MR techniques including diffusion tensor imaging (DTI) and MR spectroscopy (MRS) as imaging biomarkers for neurological impairment and tools for understanding spinal cord physiology. This review outlines the pathogenesis of cervical spondylotic myelopathy (CSM), the correlative abnormalities observed on standard MRI, the biological implications and current status of DTI and MRS as clinical tools, and future directions of MR technology in the management of CSM patients. PMID:23917647