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547 results on '"Tomography -- Methods"'

501. Optimal time-activity basis selection for exponential spectral analysis: Application to the solution of large dynamic emission tomographic reconstruction problems

Author

Maltz, Jonathan S.

Subjects
Photoemission -- Analysis, Tomography -- Methods, Tracers (Chemistry) -- Usage, Image coding -- Analysis, Business, Electronics, Electronics and electrical industries
Abstract

The clinical application of dynamic ECT reconstruction algorithms for inconsistent projection (IP) data has been beset with difficulties. These include poor scalability, numerical instability of algorithms, problems of nonuniqueness of solutions, the need to oversimplify tracer kinetics, and impractical computational burden. We present a stable reconstruction algorithm with low computational cost that is able to recover the tracer kinetics of several hundred image regions at realistic noise levels. Through optimal selection of a small set of nonnegative basis functions to describe regional time--activity curves (TACs), we are able to solve for the first-order compartmental model kinetics of each region. A nonuniform resolution pixelization of image space is employed to obtain highest resolution in regions of interest. These spatial and temporal simplifications improve numerical conditioning, provide robustness against noise, and greatly decrease the computational burden of dynamic reconstruction. We apply this algorithm to IP phantom data whose source distribution, kinetics, and count statistics are modeled after a clinical myocardial SPECT dataset. TACs of phantom regions are recovered to within a mean square error of 6%, an accuracy that proves sufficient to allow for quantitative detection of a myocardial perfusion defect within healthy myocardial tissue. Index Terms--Dynamic emission computed tomography (ECT), kinetic modeling, image reconstruction, myocardial single photon emission tomography (PET), spectral analysis, tracer kinetics.

Published
2001

502. Studies from Kogakuin University Further Understanding of Electron Microscopy (A newfield-of-viewautotracking method for online tomography reconstruction based on back-projected ray image cross-correlation)

Subjects
Electron microscopy -- Methods, Tomography -- Methods, Health, Science and technology, Kogakuin University
Abstract

By a News Reporter-Staff News Editor at Science Letter -- Fresh data on Electron Microscopy are presented in a new report. According to news reporting out of Hachioji, Japan, by [...]

Published
2014

503. Study Results from Rensselaer Polytechnic Institute Broaden Understanding of Microscopy (Dictionary-Learning-Based Reconstruction Method for Electron Tomography)

Subjects
Microscope and microscopy -- Methods, Tomography -- Methods, Health, Science and technology
Abstract

By a News Reporter-Staff News Editor at Science Letter -- Investigators publish new report on Microscopy. According to news reporting originating in Troy, New York, by NewsRx journalists, research stated, [...]

Published
2014

505. Investigators at University of Cagliari Target Optical Coherence Tomography (A novel OCT technique to measure in vivo the corneal adhesiveness for sodium carboxymethylcellulose in humans and its validity in the diagnosis of dry eye)

Subjects
Tomography -- Methods, Health, Science and technology
Abstract

By a News Reporter-Staff News Editor at Science Letter -- Investigators publish new report on Optical Coherence Tomography. According to news reporting out of Cagliari, Italy, by NewsRx editors, research [...]

Published
2014

506. Data on Optical Coherence Tomography Reported by J. Urban and Co-Researchers (Optical Coherence Tomography Imaging of Erythematotelangiectatic Rosacea During Treatment With Brimonidine Topical Gel 0.33%: A Potential Method for Treatment Outcome ...)

Subjects
Brimonidine -- Methods, Tomography -- Methods, Health, Mirvaso (Medication)
Abstract

By a News Reporter-Staff News Editor at Health & Medicine Week -- New research on Optical Coherence Tomography is the subject of a report. According to news reporting from Kent, [...]

Published
2014

507. Max-Planck-Institute for Biochemistry Reports Findings in Ultramicroscopy (Coordinate transformation based cryo-correlative methods for electron tomography and focused ion beam milling)

Subjects
Biochemistry -- Methods, Tomography -- Methods, Health, Science and technology
Abstract

By a News Reporter-Staff News Editor at Science Letter -- Current study results on Ultramicroscopy have been published. According to news originating from Martinsried, Germany, by NewsRx correspondents, research stated, [...]

Published
2014

511. Patent Application Titled 'Method and System for Controlling Computer Tomography Imaging' Published Online

Subjects
Patents -- Methods, Diagnostic imaging -- Methods, Tomography -- Methods, Patent/copyright issue, Computers, News, opinion and commentary
Abstract

By a News Reporter-Staff News Editor at Computer Weekly News -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventor Jouhikainen, Petri [...]

Published
2014

515. Researchers Submit Patent Application, 'Method for Moving X-Ray Screening Images in a Digital Radioscopy within a Digital Laminography Process and Use of a Multiaxial Imanipulator System for Implement

Subjects
Patents -- Methods, Tomography -- Methods, Patent/copyright issue, Government, Political science
Abstract

By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventor Muenker, Martin (Gevelsberg, DE), filed [...]

Published
2014

516. Researchers Submit Patent Application, 'Method for Moving X-Ray Screening Images in a Digital Radioscopy within a Digital Laminography Process and Use of a Multiaxial Imanipulator System for Implement

Subjects
Patents -- Methods, Tomography -- Methods, Patent/copyright issue, Electronics
Abstract

By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventor Muenker, Martin (Gevelsberg, DE), filed on July [...]

Published
2014

517. Three-dimensional electrical impedance tomography based on the complete electrode model

Author

Vauhkonen, Paivi J., Vauhkonen, Marko, Savolainen, Tuomo, and Kaipio, Jari P.

Subjects
Tomography -- Methods, Three-dimensional graphics -- Methods, Finite element method -- Usage, Medical imaging equipment -- Methods, Biological sciences, Business, Computers, Health care industry
Abstract

In electrical impedance tomography an approximation for the internal resistivity distribution is computed based on the knowledge of the injected currents and measured voltages on the surface of the body. It is often assumed that the injected currents are confined to the two-dimensional (2-D) electrode plane and the reconstruction is based on 2-D assumptions. However, the currents spread out in three dimensions and, therefore, off-plane structures have significant effect on the reconstructed images. In this paper we propose a finite element-based method for the reconstruction of three-dimensional resistivity distributions. The proposed method is based on the so-called complete electrode model that takes into account the presence of the electrodes and the contact impedances. Both the forward and the inverse problems are discussed and results from static and dynamic (difference) reconstructions with real measurement data are given. It is shown that in phantom experiments with accurate finite element computations it is possible to obtain static images that are comparable with difference images that are reconstructed from the same object with the empty (saline filled) tank as a reference. Index Terms - Complete electrode model, electrical impedance tomography, finite element method (FEM), ill-posed inverse problem, three-dimensional (3-D) imaging.

Published
1999

518. Three-dimensional microwave tomography: experimental prototype of the system and vector born reconstruction method

Author

Semenov, Serguei Y., Svenson, Robert H., Bulyshev, Alexander E., Souvorov, Alexander E., Nazarov, Alexei G., Sizov, Yuri E., Pavlovsky, Andrey V., Borisovv, Vladimir Y., Voinov, Boris A., Simonova, Galina I., Starostin, Andrey N., Posukh, Vitaly G., Tatsis, George P., and Baranov, Vladimir Y.

Subjects
Tomography -- Methods, Medical imaging equipment -- Equipment and supplies, Biological sciences, Business, Computers, Health care industry
Abstract

A method of image reconstruction in three-dimensional (3-D) microwave tomography in a weak dielectric contrast case has been developed. By utilizing only one component of the vector electromagnetic field this method allows successful reconstruction of images of 3-D mathematical phantoms. A prototype of the 3-D microwave tomographic system capable of imaging 3-D objects has been constructed. The system operates at a frequency of 2.36 GHz and utilizes a code-division technique. With dimensions of the cylindrical working chamber z = 40 cm and d = 60 cm, the system allows measurement of an attenuation up to 120 dB having signal-to-noise ratio about 30 dB. The direct problem solutions for different mathematical approaches were compared with an experimentally measured field distribution inside the working chamber. The tomographic system and the reconstruction method were tested in simple experimental imaging. Index Terms - Born method, image reconstruction, inverse problems, Maxwell equations, microwave imaging, tomography.

Published
1999

519. Tensor tomography

Author

Gullberg, Grant T., Roy, Dilip Ghosh, Zeng, Gengsheng L., Alexander, Andrew L., and Parker, Dennis L.

Subjects
Magnetic resonance imaging -- Usage, Scalar field theory -- Research, Tomography -- Methods, Business, Electronics, Electronics and electrical industries
Abstract

Tensors of diffusion, deformation (stress and strain), and conductivity are physical quantities of biological tissue, which can be used to characterize particular disease states. Tensor tomography may be a useful imaging technique for eliciting these tensor quantities when applied in conjunction with an imaging modality such as magnetic resonance imaging (MRI). This paper presents a method for reconstructing a 2x2 second-order tensor field from scalar projection measurements of the tensor field. The reconstruction of the four components of a 2x2 tensor may require as many as four distinct scalar measurements for each projection ray through the tensor field. Fourier projection theorems have been developed for the reconstruction of a tensor field which is decomposed into solenoidal and irrotational components. Results of a computer simulation that demonstrate the validity of the mathematical formulations are presented. A method is also proposed to obtain a diffusion tensor field tomographically from MRI projection measurements of the diffusion tensor field. The method is evaluated experimentally and results of an MRI phantom study are presented.

Published
1999

520. Nanostructure dynamics: imaging, time-resolved electron tomography provides 3-D views on ultrafast timescale

Author

Jacoby, Mitch

Subjects
Nanotechnology -- Observations, Tomography -- Methods, Chemicals, plastics and rubber industries, Engineering and manufacturing industries
Abstract

A new procedure dubbed 4-D electron tomography enables a way to examine nanoparticles not just in three-dimensions but also on a fourth dimension, which is time. This technology could be used to study structural change in nanoscale objects.

Published
2010

522. Can OCT diagnose MS?

Subjects
Multiple sclerosis -- Diagnosis, Tomography -- Methods, Tomography -- Usage
Abstract

Optical coherence tomography (OCT) can identify multiple sclerosis (MS) earlier in the course of the disease than other detection methods, and OCT could also be used to track the progression [...]

Published
2007

530. Researchers Submit Patent Application, 'Method and Evaluation Device for Determining the Position of a Structure Located in an Object to Be Examined by Means of X-Ray Computer Tomography', for Approva

Subjects
Patents -- Methods, Tomography -- Methods, Patent/copyright issue, Government, Political science
Abstract

By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Oeckl, Steven (Erlangen, DE); Schon, [...]

Published
2013

531. Researchers Submit Patent Application, 'Method and Evaluation Device for Determining the Position of a Structure Located in an Object to Be Examined by Means of X-Ray Computer Tomography', for Approva

Subjects
Patents -- Methods, Tomography -- Methods, Patent/copyright issue, Computers, News, opinion and commentary
Abstract

By a News Reporter-Staff News Editor at Computer Weekly News -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Oeckl, Steven (Erlangen, DE); Schon, Werner [...]

Published
2013

532. Patent Issued for Method of Electron Diffraction Tomography

Subjects
Patents -- Methods, Tomography -- Methods, Patent/copyright issue, Biological sciences, Health
Abstract

By a News Reporter-Staff News Editor at Life Science Weekly -- According to news reporting originating from Alexandria, Virginia, by NewsRx journalists, a patent by the inventors He, Haifeng (Rockville, [...]

Published
2013

533. Patent Application Titled 'X-Ray Diffraction Contrast Tomography (Dct) System, and X-Ray Diffraction Contrast Tomography (Dct) Method' Published Online

Subjects
X-rays -- Diffraction, Patents -- Methods, Tomography -- Methods, Patent/copyright issue, Government, Political science
Abstract

By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors LAURIDSEN, [...]

Published
2013

536. Studies Conducted at University Hospital on Isotopes Recently Published

Subjects
Boron-neutron capture therapy -- Methods -- Buildings and facilities, Tomography -- Methods, Health, Science and technology
Abstract

'This work discusses the development of online dosimetry of the boron dose via Single Photon Emission Computed Tomography (SPECT) during a BNCT treatment irradiation,' scientists in Birmingham, United Kingdom report [...]

Published
2012

538. Findings from University of California in Geoscience Reported

Subjects
Seismological research -- Methods, Tomography -- Methods, Electromagnetic noise -- Control, Health, Science and technology
Abstract

'The aim of this article is to investigate a possible way to improve ambient noise tomography by expanding the data base of useful cross-correlation measurements,' investigators in Berkeley, California report [...]

Published
2011

539. Findings in Soil Science Reported from Department of Agriculture

Subjects
Soil moisture -- Measurement, Electric resistance -- Measurement, Tomography -- Methods, Soil surveys -- Methods, Health, Science and technology
Abstract

'Surface electrical resistivity tomography (ERT) is recognized as a powerful non-invasive soil survey and monitoring method. Relationships between electrical resistivity (ER) and soil water contents that are needed to infer [...]

Published
2011

540. New Earth Science Research from F. Keshvari et al Outlined

Subjects
Seismological research -- Methods, Earth -- Mantle, Tomography -- Methods, Health, Science and technology
Abstract

'Non-linear teleseismic S-phase tomography across the Zagros collision zone in southwestern Iran is used to determine a high-resolution image of the upper-mantle structure. The inversion was done using 41 high-quality [...]

Published
2011

541. New Findings from Cornell University in the Area of Algorithms Described

Subjects
Image processing -- Methods -- Technology application, Algorithms -- Analysis -- Research -- Reports -- Usage, Tomography -- Methods, Algorithm, Technology application, Health, Science and technology
Abstract

'Sulfolobus Turreted Icosahedral Virus (STIV) experiences an extra-cellular environment of near boiling acid (80 degrees C, pH 3) and particles purified under these conditions were previously analyzed by cryo electron [...]

Published
2011

542. A channel that traps sound

Author

Leal, Jose H.

Subjects
Tomography -- Methods, Sound-waves -- Speed, Sounds -- Research
Published
1991

544. Depth imaging shows salt-like shale features on Scotian slope

Author

Gordon, Mark B., Newding, Robert H., O'Dowd, John, Harvey, Paul J., and MacDonald, Jack

Subjects
Petroleum industry -- Research, Oil and gas exploration -- Methods, Tomography -- Methods, Business, Petroleum, energy and mining industries
Abstract

THE AUTHORS Mark B. Gordon has done geological research in Central America, Cuba, France, and Saudi Arabia while involved in post-doctorate work at Rice University and the University of Paris. [...]

Published
1999

545. Electrical resistance reveals bodily health

Subjects
Tomography -- Methods, Diagnostic imaging -- Innovations, Business, Electronics and electrical industries
Abstract

Electrical impedance tomography (eit) is a new technique that helps monitor and identify defects in the internal organs of the human body using the variations in electrical resistance to develop images of the region under eit analysis. Eit has high speed, is low cost, highly sensitive and provides a higher spatial resolution than other methods such as NMR and x-ray computer tomography. The technique involves 16 electrodes and a multiplexer to control current direction in the electrodes. Lung volume measurements validate the efficiency of eit, which is also applicable for analyzing tissue temperature changes, gastric function and lung water changes.

Published
1994

546. New Imaging Technique Could Improve Outcome Of Popular Heart Procedure

Subjects
Angioplasty -- Research, Cardiac patients -- Care and treatment, Tomography -- Methods, Health, Health care industry, Harvard University. School of Medicine -- Research
Abstract

2001 MAY 13 - (NewsRx.com & NewsRx.net) -- Researchers at Harvard Medical School may have found a way to give patients peace of mind after undergoing stent angioplasty to open [...]

Published
2001

547. Microscope images unstained organics

Subjects
tomography -- Methods, Microscope and microscopy -- Innovations, Molecules, Chemicals, plastics and rubber industries, Engineering and manufacturing industries
Published
1982

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