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1

Na and Li ion diffusion in modified ASTM C 1260 test by Magnetic Resonance Imaging (MRI)  

SciTech Connect

In the current study, MRI was applied to investigate lithium and sodium ion diffusion in cement paste and mortars containing inert sand and borosilicate glass. Paste and mortars were treated by complying with ASTM C 1260. Lithium and sodium distribution profiles were collected at different ages after different treatments. Results revealed that sodium ions had a greater diffusion rate than lithium ions, suggesting that Na reaches the aggregate particle surface before Li. Results also showed that Na and Li ions had a competitive diffusion process in mortars; soaking in a solution with higher [Li] favored Li diffusion but hindered Na diffusion. In mortars containing glass, a substantial amount of Li was consumed by the formation of ASR products. When [Li] in soaking solution was reduced to 0.37 N, a distinctive Na distribution profile was observed, indicating the free-state Na ions were continuously transformed to solid reaction products by ASR. Hence, in the modified ASTM C 1260 test, [Li] in the storage solution should be controlled at 0.74 N, in order to completely prevent the consumption of Na ions and thus stop ASR.

Feng, X. [Department of Civil Engineering, University of New Brunswick, Fredericton, NB (Canada)], E-mail: XFeng@ctlgroup.com; Balcom, B.J. [MRI Center, Department of Physics, University of New Brunswick, Fredericton, NB (Canada); Thomas, M.D.A.; Bremner, T.W. [Department of Civil Engineering, University of New Brunswick, Fredericton, NB (Canada)

2008-12-15T23:59:59.000Z

2

Power Quality Investigation at a Midwest Hospital: Magnetic Resonance Imaging System  

Science Conference Proceedings (OSTI)

Recently, a Midwest hospital contacted its electric utility about malfunctions involving imaging systems including magnetic resonance imaging (MRI) and computed tomography (CT). The MRI system was the primary concern for the hospital. The MRI system was manufactured by a leading imaging system manufacturer and the CT system was manufactured by another leading imaging system manufacturer. To begin investigating the problem, the hospital requested that power-line monitoring be conducted at the facility. Th...

2007-07-26T23:59:59.000Z

3

Reconstruction algorithms for MRI  

E-Print Network (OSTI)

This dissertation presents image reconstruction algorithms for Magnetic Resonance Imaging (MRI) that aims to increase the imaging efficiency. Algorithms that reduce imaging time without sacrificing the image quality and ...

Bilgic?, Berkin

2013-01-01T23:59:59.000Z

4

New MRI Phantoms for Diffusion and More  

Science Conference Proceedings (OSTI)

... Magnetic resonance imaging (MRI) has become an indispensable tool for diagnosing, treating, and understanding a host of medical conditions ...

2013-07-01T23:59:59.000Z

5

Multimodal neuroimaging with simultaneous electroencephalogram and high-field functional magnetic resonance imaging  

E-Print Network (OSTI)

Simultaneous recording of electroencephalogram (EEG) and functional magnetic resonance imaging (tMRI) is an important emerging tool in functional neuroimaging with the potential to reveal new mechanisms for brain function ...

Purdon, Patrick L. (Patrick Lee), 1974-

2005-01-01T23:59:59.000Z

6

Low field magnetic resonance imaging  

DOE Patents (OSTI)

A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

Pines, Alexander (Berkeley, CA); Sakellariou, Dimitrios (Billancourt, FR); Meriles, Carlos A. (Fort Lee, NJ); Trabesinger, Andreas H. (London, GB)

2010-07-13T23:59:59.000Z

7

Application of Parallel Imaging to Murine Magnetic Resonance Imaging  

E-Print Network (OSTI)

The use of parallel imaging techniques for image acceleration is now common in clinical magnetic resonance imaging (MRI). There has been limited work, however, in translating the parallel imaging techniques to routine animal imaging. This dissertation describes foundational level work to enable parallel imaging of mice on a 4.7 Tesla/40 cm bore research scanner. Reducing the size of the hardware setup associated with typical parallel imaging was an integral part of achieving the work, as animal scanners are typically small-bore systems. To that end, an array element design is described that inherently decouples from a homogenous transmit field, potentially allowing for elimination of typically necessary active detuning switches. The unbalanced feed of this "dual-plane pair" element also eliminates the need for baluns in this case. The use of the element design in a 10-channel adjustable array coil for mouse imaging is presented, styled as a human cardiac top-bottom half-rack design. The design and construction of the homogenous transmit birdcage coil used is also described, one of the necessary components to eliminating the active detuning networks on the array elements. In addition, the design of a compact, modular multi-channel isolation preamplifier board is described, removing the preamplifiers from the elements and saving space in the bore. Several additions/improvements to existing laboratory infrastructure needed for parallel imaging of live mice are also described, including readying an animal preparation area and developing the ability to maintain isoflurane anesthesia delivery during scanning. In addition, the ability to trigger the MRI scanner to the ECG and respiratory signals from the mouse in order to achieve images free from physiological motion artifacts is described. The imaging results from the compact 10-channel mouse array coils are presented, and the challenges associated with the work are described, including difficulty achieving sample-loss dominance and signal-to-noise ratio (SNR) limitations. In conclusion, in vivo imaging of mice with cardiac and respiratory gating has been demonstrated. Compact array coils tailored for mice have been studied and potential future work and design improvements for our lab in this area are discussed.

Chang, Chieh-Wei 1980-

2012-12-01T23:59:59.000Z

8

Ex-Situ High Resolution NMR and MRI - Lawrence Berkeley ...  

Alexander Pines and colleagues have opened the way to high resolution ex situ nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).

9

Automatic segmentation of non-enhancing brain tumors in magnetic resonance images  

Science Conference Proceedings (OSTI)

Tumor segmentation from magnetic resonance (MR) images may aid in tumor treatment by tracking the progress of tumor growth and/or shrinkage. In this paper we present the first automatic segmentation method which separates non-enhancing brain tumors from ... Keywords: Automatic tissue classification, Fuzzy clustering, Image processing, MRI, Non-enhancing brain tumors

Lynn M Fletcher-Heath; Lawrence O Hall; Dmitry B Goldgof; F.Reed Murtagh

2001-01-01T23:59:59.000Z

10

Imaging agents for in vivo magnetic resonance and scintigraphic imaging  

DOE Patents (OSTI)

Methods are provided for in vivo magnetic resonance imaging and/or scintigraphic imaging of a subject using chelated transition metal and lanthanide metal complexes. Novel ligands for these complexes are provided.

Engelstad, Barry L. (Orinda, CA); Raymond, Kenneth N. (Berkeley, CA); Huberty, John P. (Corte Madera, CA); White, David L. (Oakland, CA)

1991-01-01T23:59:59.000Z

11

Imaging agents for in vivo magnetic resonance and scintigraphic imaging  

DOE Patents (OSTI)

Methods are provided for in vivo magnetic resonance imaging and/or scintigraphic imaging of a subject using chelated transition metal and lanthanide metal complexes. Novel ligands for these complexes are provided. No Drawings

Engelstad, B.L.; Raymond, K.N.; Huberty, J.P.; White, D.L.

1991-04-23T23:59:59.000Z

12

Plenary lecture 2: local surface approximation for edge structure preserving 3-D image denoising  

Science Conference Proceedings (OSTI)

In various applications, including magnetic resonance imaging (MRI) and functional MRI (fMRI), 3-D images get increasingly popular. To improve reliability of subsequent image analyses, 3-D image denoising is often a necessary pre-processing step, which ...

Peihua Qiu

2011-01-01T23:59:59.000Z

13

Magnetic resonance imaging in Mexico  

Science Conference Proceedings (OSTI)

MR imaging has experienced an important growth worldwide and in particular in the USA and Japan. This imaging technique has also shown an important rise in the number of MR imagers in Mexico. However

A. O. Rodriguez; R. Rojas; F. A. Barrios

2001-01-01T23:59:59.000Z

14

Microfluidically Cryo-Cooled Planar Coils for Magnetic Resonance Imaging  

E-Print Network (OSTI)

High signal-to-noise ratio (SNR) is typically required for higher resolution and faster speed in magnetic resonance imaging (MRI). Planar microcoils as receiver probes in MRI systems offer the potential to be configured into array elements for fast imaging as well as to enable the imaging of extremely small objects. Microcoils, however, are thermal noise dominant and suffer limited SNR. Cryo-cooling for the microcoils can reduce the thermal noise, however conventional cryostats are not optimum for the microcoils because they typically use a thick vacuum gap to keep samples to be imaged to near room temperature during cryo-cooling. This vacuum gap is typically larger than the most sensitive region of the microcoils that defines the imaging depth, which is approximately the same as the diameters of the microcoils. Here microfluidic technology is utilized to locally cryo-cool the microcoils and minimize the thermal isolation gap so that the imaging surface is within the imaging depth of the microcoils. The first system consists of a planar microcoil with microfluidically cryo-cooling channels, a thin N2 gap and an imaging. The microcoil was locally cryo-cooled while maintaining the sample above 8°C. MR images using a 4.7 Tesla MRI system shows an average SNR enhancement of 1.47 fold. Second, the system has been further developed into a cryo-cooled microcoil system with inductive coupling to cryo-cool both the microcoil and the on-chip microfabricated resonating capacitor to further improve the Q improvement. Here inductive coupling was used to eliminate the physical connection between the microcoil and the tuning network so that a single cryocooling microfluidic channel could enclose both the microcoil and the capacitor with minimum loss in cooling capacity. Q improvement was 2.6 fold compared to a conventional microcoil with high-Q varactors and transmission line connection. Microfluidically tunable capacitors with the 653% tunability and Q of 1.3 fold higher compared to a conventional varactor have been developed and demonstrated as matching/tuning networks as a proof of concept. These developed microfluidically cryo-cooling system and tunable capacitors for improving SNR will potentially allow MR microcoils to have high-resolution images over small samples.

Koo, Chiwan

2013-08-01T23:59:59.000Z

15

Liver Isolation in Abdominal MRI  

Science Conference Proceedings (OSTI)

This work presents a method for liver isolation in magnetic resonance imaging (MRI) abdomen images. It is based on a priori statistical information about the shape of the liver obtained from a training set using the segmentation approach. Morphological ... Keywords: Abdominal axial MRI, Morphological operations, Object extraction, Region merging, Watershed transform

Rajasvaran Logeswaran; Tan Wooi Haw; Shakowat Zaman Sarker

2008-08-01T23:59:59.000Z

16

Design of an MRI compatible robot for wrist rehabilitation  

E-Print Network (OSTI)

Magnetic Resonance Imaging (MRI) can be used to study the effects of robotic therapy on stroke patients. This thesis focuses on the design of an MRI compatible wrist robot to be used as a clinical tool for studying the ...

Mendelowitz, Sarah E. (Sarah Elizabeth), 1980-

2005-01-01T23:59:59.000Z

17

Magnetic resonance imaging of solvent transport in polymer networks  

SciTech Connect

The spectroscopic technique of magnetic resonance imaging (MRI) has recently provided a new window into transport of solvents in polymer networks. Diffusion of solvent as a rate-controlling phenomenon is paramount to understanding transport in many important industrial and biological processes, such as upgrading fossil fuels, film casting and coating, development of photoresists, design of drug-delivery systems, development of solvent resistant polymers, etc. By MRI mapping the migration of solvent molecules through various polymer specimens, researchers Robert Botto and George Cody of Argonne National Laboratory, with support from the Division of Chemical Sciences at DOE, were able to characterize and distinguish between different modes of transport behavior associated with fundamentally different types of polymer systems. The method was applied to rubbers, glassy polymers, and coals. In polymers shown to undergo a glass transition from a rigid to rubbery state, a sharply defined solvent front was observed that propagated through specimens in the manner of a constant velocity shock wave. This behavior was contrasted with a smooth solvent concentration gradient found in polymer systems where no glass transition was observed. The results of this analysis have formed the basis of a new model of anomalous transport in polymeric solids and are helping to ascertain fundamental information on the molecular architectures of these materials.

Botto, R.E.; Cody, G.D.

1995-02-01T23:59:59.000Z

18

Magnetic Resonance Imaging at Princeton, UofV, and UNH | U.S. DOE Office of  

Office of Science (SC) Website

Magnetic Resonance Imaging at Magnetic Resonance Imaging at Princeton, UofV, and UNH Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Magnetic Resonance Imaging at Princeton, UofV, and UNH Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: MRI for hyperpolarized gases Developed at: Princeton, University of Virginia, University of New Hampshire

19

A generalized family of fixed-radius distribution-based distance measures for content-based fMRI image retrieval  

Science Conference Proceedings (OSTI)

We present a family of distance measures for comparing activation patterns captured in fMRI images. We model an fMRI image as a spatial object with varying density, and measure the distance between two fMRI images using a novel fixed-radius, distribution-based ... Keywords: Brain imaging, Content-based image retrieval, fMRI image matching

John Novatnack; Nicu Cornea; Ali Shokoufandeh; Deborah Silver; Sven Dickinson; Paul Kantor; Bing Bai

2008-09-01T23:59:59.000Z

20

Nuclear magnetic resonance contrast agents  

DOE Patents (OSTI)

This invention relates to the field of nuclear magnetic resonance imaging and nuclear magnetic resonance spectroscopy, also known simply as magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). MRI and MRS are particularly useful in medical research and diagnosis. MRI may be used in addition to x-ray imaging. This invention concerns a family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 2 figs.

Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

1989-01-24T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Edge structure preserving 3-D image denoising  

Science Conference Proceedings (OSTI)

In various applications, including magnetic resonance imaging (MRI) and functional MRI (fMRI), 3- D images get increasingly popular. To improve reliability of subsequent image analyses, 3-D image denoising is often a necessary pre-processing step, which ... Keywords: edge-preserving image restoration, jump regression analysis, surface estimation

Peihua Qiu; Partha Sarathi Mukherjee

2011-01-01T23:59:59.000Z

22

Direct imaging of neural currents using ultra-low field magnetic resonance techniques  

DOE Patents (OSTI)

Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

Volegov, Petr L. (Los Alamos, NM); Matlashov, Andrei N. (Los Alamos, NM); Mosher, John C. (Los Alamos, NM); Espy, Michelle A. (Los Alamos, NM); Kraus, Jr., Robert H. (Los Alamos, NM)

2009-08-11T23:59:59.000Z

23

Methods for functional brain imaging  

E-Print Network (OSTI)

Magnetic resonance imaging (MRI) has demonstrated the potential for non-invasive mapping of structure and function (fMRI) in the human brain. In this thesis, we propose a series of methodological developments towards ...

Witzel, Thomas, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

24

Dynamic Contrast-Enhanced Magnetic Resonance Imaging of the Metastatic Potential of Melanoma Xenografts  

SciTech Connect

Purpose: Gadolinium diethylene-triamine penta-acetic acid (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been suggested as a useful noninvasive method for characterizing the physiologic microenvironment of tumors. In the present study, we investigated whether Gd-DTPA-based DCE-MRI has the potential to provide biomarkers for hypoxia-associated metastatic dissemination. Methods and Materials: C-10 and D-12 melanoma xenografts were used as experimental tumor models. Pimonidazole was used as a hypoxia marker. A total of 60 tumors were imaged, and parametric images of K{sup trans} (volume transfer constant of Gd-DTPA) and v{sub e} (fractional distribution volume of Gd-DTPA) were produced by pharmacokinetic analysis of the DCE-MRI series. The host mice were killed immediately after DCE-MRI, and the primary tumor and the lungs were resected and prepared for histologic assessment of the fraction of pimonidazole-positive hypoxic tissue and the presence of lung metastases, respectively. Results: Metastases were found in 11 of 26 mice with C-10 tumors and 14 of 34 mice with D-12 tumors. The primary tumors of the metastatic-positive mice had a greater fraction of hypoxic tissue (p = 0.00031, C-10; p < 0.00001, D-12), a lower median K{sup trans} (p = 0.0011, C-10; p < 0.00001, D-12), and a lower median v{sub e} (p = 0.014, C-10; p = 0.016, D-12) than the primary tumors of the metastatic-negative mice. Conclusions: These findings support the clinical attempts to establish DCE-MRI as a method for providing biomarkers for tumor aggressiveness and suggests that primary tumors characterized by low K{sup trans} and low v{sub e} values could have a high probability of hypoxia-associated metastatic spread.

Ovrebo, Kirsti Marie; Ellingsen, Christine; Galappathi, Kanthi [Group of Radiation Biology and Tumor Physiology, Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway); Rofstad, Einar K., E-mail: einar.k.rofstad@rr-research.no [Group of Radiation Biology and Tumor Physiology, Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway)

2012-05-01T23:59:59.000Z

25

Magnetic resonance imaging (MRI) has opened unparalleled new  

E-Print Network (OSTI)

Approach to Dynamic Energy Minimization in Wireless Transceivers", A. Iranli, H. Fatemi, M. Pedram, Int;17 Optimization problem · Minimize total energy consumption for a link ­ (A) Minimize energy at transmitter ­ (B of SNR and mod. level Vector upper bound on overall Energy consumption #12;20 Some performance results

Shamir, Ron

26

Minimally Invasive Magnetic Resonance Imaging-Guided Free-Hand Aspiration of Symptomatic Nerve Route Compressing Lumbosacral Cysts Using a 1.0-Tesla Open Magnetic Resonance Imaging System  

SciTech Connect

Purpose: To evaluate the feasibility of minimally invasive magnetic resonance imaging (MRI)-guided free-hand aspiration of symptomatic nerve route compressing lumbosacral cysts in a 1.0-Tesla (T) open MRI system using a tailored interactive sequence. Materials and Methods: Eleven patients with MRI-evident symptomatic cysts in the lumbosacral region and possible nerve route compressing character were referred to a 1.0-T open MRI system. For MRI interventional cyst aspiration, an interactive sequence was used, allowing for near real-time position validation of the needle in any desired three-dimensional plane. Results: Seven of 11 cysts in the lumbosacral region were successfully aspirated (average 10.1 mm [SD {+-} 1.9]). After successful cyst aspiration, each patient reported speedy relief of initial symptoms. Average cyst size was 9.6 mm ({+-}2.6 mm). Four cysts (8.8 {+-} 3.8 mm) could not be aspirated. Conclusion: Open MRI systems with tailored interactive sequences have great potential for cyst aspiration in the lumbosacral region. The authors perceive major advantages of the MR-guided cyst aspiration in its minimally invasive character compared to direct and open surgical options along with consecutive less trauma, less stress, and also less side-effects for the patient.

Bucourt, Maximilian de, E-mail: mdb@charite.de; Streitparth, Florian, E-mail: florian.streitparth@charite.de; Collettini, Federico [Charite-University Medicine, Department of Radiology (Germany); Guettler, Felix [Jena University, Department of Radiology (Germany); Rathke, Hendrik; Lorenz, Britta; Rump, Jens; Hamm, Bernd [Charite-University Medicine, Department of Radiology (Germany); Teichgraeber, U. K. [Jena University, Department of Radiology (Germany)

2012-02-15T23:59:59.000Z

27

Method for nuclear magnetic resonance imaging  

DOE Patents (OSTI)

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

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

1988-05-26T23:59:59.000Z

28

A Signal-Inducing Bone Cement for Magnetic Resonance Imaging-Guided Spinal Surgery Based on Hydroxyapatite and Polymethylmethacrylate  

Science Conference Proceedings (OSTI)

The aim of this study was to develop a signal-inducing bone cement for magnetic resonance imaging (MRI)-guided cementoplasty of the spine. This MRI cement would allow precise and controlled injection of cement into pathologic lesions of the bone. We mixed conventional polymethylmethacrylate bone cement (PMMA; 5 ml methylmethacrylate and 12 g polymethylmethacrylate) with hydroxyapatite (HA) bone substitute (2-4 ml) and a gadolinium-based contrast agent (CA; 0-60 {mu}l). The contrast-to-noise ratio (CNR) of different CA doses was measured in an open 1.0-Tesla scanner for fast T1W Turbo-Spin-Echo (TSE) and T1W TSE pulse sequences to determine the highest signal. We simulated MRI-guided cementoplasty in cadaveric spines. Compressive strength of the cements was tested. The highest CNR was (1) 87.3 (SD 2.9) in fast T1W TSE for cements with 4 {mu}l CA/ml HA (4 ml) and (2) 60.8 (SD 2.4) in T1W TSE for cements with 1 {mu}l CA/ml HA (4 ml). MRI-guided cementoplasty in cadaveric spine was feasible. Compressive strength decreased with increasing amounts of HA from 46.7 MPa (2 ml HA) to 28.0 MPa (4 ml HA). An MRI-compatible cement based on PMMA, HA, and CA is feasible and clearly visible on MRI images. MRI-guided spinal cementoplasty using this cement would permit direct visualization of the cement, the pathologic process, and the anatomical surroundings.

Wichlas, Florian, E-mail: florian.wichlas@charite.de; Seebauer, Christian J.; Schilling, Rene [University Charite, Center for Musculoskeletal Surgery (Germany); Rump, Jens [University Charite, Department of Radiology (Germany); Chopra, Sascha S. [University Charite, Center for Musculoskeletal Surgery (Germany); Walter, Thula; Teichgraeber, Ulf K. M. [University Charite, Department of Radiology (Germany); Bail, Hermann J. [University Charite, Center for Musculoskeletal Surgery (Germany)

2012-06-15T23:59:59.000Z

29

Design and Development of Calcium Sensitive Contrast Agents for fMRI  

E-Print Network (OSTI)

There is a considerable interest in new technologies that allow noninvasive imaging of physiological parameters in living systems, especially in the neuroscience. Magnetic resonance imaging (MRI) is a very powerful tool ...

Atanasijevic, Tatjana, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

30

Joint estimation and correction of geometric distortions for EPI functional MRI using harmonic retrieval  

E-Print Network (OSTI)

Magnetic resonance imaging (MRI) uses applied spatial variations in the magnetic field to encode spatial position. Therefore, nonuniformities in the main magnetic field can cause image distortions. In order to correct the ...

Nguyen, Hien M.

31

BASIS FUNCTIONS FOR ESTIMATING INTRA-VOXEL STRUCTURE IN DW-MRI  

E-Print Network (OSTI)

BASIS FUNCTIONS FOR ESTIMATING INTRA-VOXEL STRUCTURE IN DW-MRI Alonso Ramírez-Manzanares, Mariano Functions for Estimating Intra­voxel Structure in DW­MRI Alonso Ram´irez-Manzanares, Mariano Rivera, Baba C­voxel fiber paths, using Diffusion Weighted Magnetic Resonance Images (DW-MRI). The method recovers the intra

Rivera, Mariano

32

A numerical approach : broadband technologies for efficient Magnetic Resonance Imaging  

E-Print Network (OSTI)

(cont.) independent receiver coils in parallel or time-axis compression, can be cast as complementary to broadband MRI encoding. This affords broadband non-Fourier MRI with time efficiencies over current fast MRI methods. ...

Mitsouras, Dimitrios, 1976-

2004-01-01T23:59:59.000Z

33

Multi-fiber Reconstruction from DW-MRI using a Continuous Mixture of Hyperspherical von  

E-Print Network (OSTI)

Multi-fiber Reconstruction from DW-MRI using a Continuous Mixture of Hyperspherical von Mises Magnetic Resonance Imaging (DW-MRI), arguably one of the most important imaging inventions of the twentieth geometries such as fiber crossings ( [21, 17, 6]) and connectivity of different brain regions ([8]). DW

Kumar, Ritwik

34

Off-resonance and detuned surface coils for B? inhomogeneity in 7-Tesla MRI  

E-Print Network (OSTI)

A problem with high-field MRI is the lack of B1 homogeneity, particularly signal cancellation in the outer parts of the head. Here we attempt to correct this by adding surface coils. To adjust the mutual coupling, we vary ...

Zakszewski, Elizabeth K

2006-01-01T23:59:59.000Z

35

Numerical field simulation for parallel transmission in MRI at 7 tesla  

E-Print Network (OSTI)

Parallel transmission (pTx) is a promising improvement to coil design that has been demonstrated to mitigate B1* inhomogeneity, manifest as center brightening, for high-field magnetic resonance imaging (MRI). Parallel ...

Bernier, Jessica A. (Jessica Ashley)

2011-01-01T23:59:59.000Z

36

Solutions to various problems in reversible cooling fMRI studies  

E-Print Network (OSTI)

Functional magnetic resonance imaging (fMRI) has been very useful in helping neuroscientists map the brain. One tool to investigate the interactions between brain regions is to disable a small region in the brain, and look ...

Khachaturian, Mark Haig, 1979-

2003-01-01T23:59:59.000Z

37

Mapping the Flip Angle in Magnetic Resonance Imaging Using the Accelerated 3D Look-Locker Sequence.  

E-Print Network (OSTI)

??In the ongoing quest to extract more information from MRI images, there has arisen a need to rapidly map the flip angle. This has been… (more)

Wade, Trevor P

2010-01-01T23:59:59.000Z

38

Quantitative susceptibility mapping and susceptibility-based distortion correction of echo planar images  

E-Print Network (OSTI)

The field of medical image analysis continues to expand as magnetic resonance imaging (MRI) technology advances through increases in field strength and the development of new image acquisition and reconstruction methods. ...

Poynton, Clare (Clare Brenna)

2012-01-01T23:59:59.000Z

39

Magnetic Resonance Imaging-Guided Osseous Biopsy in Children With Chronic Recurrent Multifocal Osteomyelitis  

SciTech Connect

Purpose: To report the safety and diagnostic performance of magnetic resonance (MRI)-guided core biopsy of osseous lesions in children with chronic recurrent multifocal osteomyelitis (CRMO) that were visible on MRI but were occult on radiography and computed tomography (CT). Materials and Methods: A retrospective analysis of MRI-guided osseous biopsy performed in seven children (four girls and three boys; mean age 13 years (range 11 to 14) with CRMO was performed. Indication for using MRI guidance was visibility of lesions by MRI only. MRI-guided procedures were performed with 0.2-Tesla (Magnetom Concerto; Siemens, Erlangen, Germany; n = 5) or 1.5-T (Magnetom Espree; Siemens; n = 2) open MRI systems. Core needle biopsy was obtained using an MRI-compatible 4-mm drill system. Conscious sedation or general anesthesia was used. Parameters evaluated were lesion visibility, technical success, procedure time, complications and microbiology, cytology, and histopathology findings. Results: Seven of seven (100%) targeted lesions were successfully visualized and sampled. All obtained specimens were sufficient for histopathological analysis. Length of time of the procedures was 77 min (range 64 to 107). No complications occurred. Histopathology showed no evidence of malignancy, which was confirmed at mean follow-up of 50 months (range 28 to 78). Chronic nonspecific inflammation characteristic for CRMO was present in four of seven (58%) patients, and edema with no inflammatory cells was found in three of seven (42%) patients. There was no evidence of infection in any patient. Conclusion: MRI-guided osseous biopsy is a safe and accurate technique for the diagnosis of pediatric CRMO lesions that are visible on MRI only.

Fritz, Jan, E-mail: jfritz9@jhmi.edu [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Tzaribachev, Nikolay [University Children's Hospital, Eberhard-Karls-University Tuebingen, Division of Pediatric Rheumatology (Germany); Thomas, Christoph [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology (Germany); Wehrmann, Manfred [Eberhard-Karls-University Tuebingen, Department of Pathology (Germany); Horger, Marius S. [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology (Germany); Carrino, John A. [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Koenig, Claudius W.; Pereira, Philippe L. [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology (Germany)

2012-02-15T23:59:59.000Z

40

Magnetic Resonance Imaging at Princeton, UofV, and UNH | U.S...  

Office of Science (SC) Website

Magnetic Resonance Imaging at Princeton, UofV, and UNH Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff...

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

An intelligent modified fuzzy c-means based algorithm for bias estimation and segmentation of brain MRI  

Science Conference Proceedings (OSTI)

The segmentation of magnetic resonance images (MRI) is a challenging problem that has received an enormous amount of attention lately. Many researchers have applied various techniques however fuzzy c-means (FCM) based algorithms have produced better ... Keywords: FCM, MRI, Medical image processing, Segmentation

M. Y. Siyal; Lin Yu

2005-10-01T23:59:59.000Z

42

Urinary Tract Effects After Multifocal Nonthermal Irreversible Electroporation of the Kidney: Acute and Chronic Monitoring by Magnetic Resonance Imaging, Intravenous Urography and Urinary Cytology  

Science Conference Proceedings (OSTI)

Purpose: The nonthermal irreversible electroporation (NTIRE) is a novel potential ablation modality for renal masses. The aim of this study was the first evaluation of NTIRE's effects on the renal urine-collecting system using intravenous urography (IVU) and urinary cytology in addition to histology and magnetic resonance imaging (MRI). Methods: Eight percutaneous NTIRE ablations of the renal parenchyma, including the calyxes or pelvis, were performed in three male swine. MRI, IVU, histology, and urinary cytology follow-ups were performed within the first 28 days after treatment. Results: MRI and histological analysis demonstrated a localized necrosis 7 days and a localized scarification of the renal parenchyma with complete destruction 28 days after NTIRE. The urine-collecting system was preserved and showed urothelial regeneration. IVU and MRI showed an unaltered normal morphology of the renal calyxes, pelvis, and ureter. A new urinary cytology phenomenon featured a temporary degeneration by individual vacuolization of detached transitional epithelium cells within the first 3 days after NTIRE. Conclusions: This first urographical, urine-cytological, and MRI evaluation after porcine kidney NTIRE shows multifocal parenchyma destruction while protecting the involved urine-collecting system with regenerated urothelial tissue. NTIRE could be used as a targeted ablation method of centrally located renal masses.

Wendler, Johann Jakob, E-mail: johann.wendler@med.ovgu.de [University of Magdeburg, Department of Urology (Germany); Pech, Maciej [University of Magdeburg, Department of Radiology and Nuclear Medicine (Germany); Porsch, Markus; Janitzky, Andreas [University of Magdeburg, Department of Urology (Germany); Fischbach, Frank [University of Magdeburg, Department of Radiology and Nuclear Medicine (Germany); Buhtz, Peter; Vogler, Klaus [University of Magdeburg, Institute of Pathology (Germany); Huehne, Sarah [University of Magdeburg, Department of Urology (Germany); Borucki, Katrin [University of Magdeburg, Institute of Clinical Chemistry (Germany); Strang, Christof [University of Magdeburg, Department of Anaesthesiology (Germany); Mahnkopf, Dirk [Institute of Medical Technology and Research (Germany); Ricke, Jens [University of Magdeburg, Department of Radiology and Nuclear Medicine (Germany); Liehr, Uwe-Bernd [University of Magdeburg, Department of Urology (Germany)

2012-08-15T23:59:59.000Z

43

A robust kernel-based fuzzy c-means algorithm by incorporating suppressed and magnified membership for MRI image segmentation  

Science Conference Proceedings (OSTI)

Bias-corrected fuzzy c-means (BCFCM) algorithm with spatial information has been proven effective for image segmentation. It still lacks enough robustness to noise and outliers. Some kernel versions of FCM with spatial constraints, such as KFCM_S1, ... Keywords: Kernel-based FCM, fuzzy c-means (FCM), image segmentation, magic resonance image segmentation, spatial bias correction, suppressed membership

Hsu-Shen Tsai; Wen-Liang Hung; Miin-Shen Yang

2012-10-01T23:59:59.000Z

44

Segmentation of female pelvic organs in axial magnetic resonance images using coupled geometric deformable models  

Science Conference Proceedings (OSTI)

The segmentation of pelvic structures in magnetic resonance (MR) images of the female pelvic cavity is a challenging task. This paper proposes the use of three novel geometric deformable models to segment the bladder, vagina and rectum in axial MR images. ... Keywords: Bladder, Image segmentation, Imaging appearance, Level set, Prior shape knowledge, Rectum, Vagina

Zhen Ma; Renato M. Natal Jorge; Teresa Mascarenhas; JoãO Manuel R. S. Tavares

2013-05-01T23:59:59.000Z

45

Finding the optimal compression level for strain-encoded (SENC) breast MRI; simulations and phantom experiments  

Science Conference Proceedings (OSTI)

Breast cancer is the most common cancer among women and the second highest cause of cancer-related death. Diagnostic magnetic resonance imaging (MRI) is recommended to screen high-risk patients. Strain-Encoded (SENC) can improve MRI's specificity by ...

Ahmed A. Harouni; Michael A. Jacobs; Nael F. Osman

2011-09-01T23:59:59.000Z

46

A PHYSICAL BASIS FOR MULTI-FIBER RECONSTRUCTION FROM DW-MRI DATA Ritwik Kumar1  

E-Print Network (OSTI)

A PHYSICAL BASIS FOR MULTI-FIBER RECONSTRUCTION FROM DW-MRI DATA Ritwik Kumar1 , Angelos Barmpoutis to model the signal attenuation obtained from Diffusion Weighted Magnetic Resonance Imaging (DW-value, gradient pulse duration, pulse separation etc.) involved in the DW-MRI acquisition pro- cess. To address

Kumar, Ritwik

47

Spectroscopic imaging through magnetic resonance for brain tumour diagnostics: Recent achievements, dilemmas and potential solutions via advances in signal processing  

Science Conference Proceedings (OSTI)

In the very recent period Magnetic Resonance Spectroscopy (MRS) and Spectroscopic Imaging (MRSI) have become key diagnostic modalities for neuro-oncology. MRS and MRSI are now applied extensively for initial detection of brain tumours, for histopathologic ... Keywords: biomedical imaging, brain tumours, magnetic resonance spectroscopic imaging, magnetic resonance spectroscopy, metastatic disease

Karen Belki?; Dževad Belki?

2004-04-01T23:59:59.000Z

48

HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006  

E-Print Network (OSTI)

This team taught, multidisciplinary course covers the fundamentals of magnetic resonance imaging relevant to the conduct and interpretation of human brain mapping studies. The challenges inherent in advancing our knowledge ...

Gollub, Randy L.

49

A Novel MRI Marker for Prostate Brachytherapy  

Science Conference Proceedings (OSTI)

Purpose: Magnetic resonance imaging (MRI) is the optimal imaging modality for the prostate and surrounding critical organ structures. However, on MRI, the titanium radioactive seeds used for brachytherapy appear as black holes (negative contrast) and cannot be accurately localized. We sought to develop an encapsulated contrast agent marker (ECAM) with high-signal intensity on MRI to permit accurate localization of radioactive seeds with MRI during and after prostate brachytherapy. Methods and Materials: We investigated several agents with paramagnetic and superparamagnetic properties. The agents were injected into titanium, acrylic, and glass seeds, which were linked together in various combinations and imaged with MRI. The agent with the greatest T1-weighted signal was tested further in a canine prostate and agarose phantom. Studies were performed on a 1.5-T clinical MRI scanner. Results: The cobalt-chloride complex contrast (C4) agent with stoichiometry (CoCl{sub 2}){sub 0.8}(C{sub 2}H{sub 5}NO{sub 2}){sub 0.2} had the greatest T1-weighted signal (positive contrast) with a relaxivity ratio >1 (r{sub 2}/r{sub 1} = 1.21 {+-} 0.29). Acrylic-titanium and glass-titanium seed strands were clearly visualized with the encapsulated contrast agent marker. Conclusion: We have developed a novel ECAM that permits positive identification of the radioactive seeds used for prostate brachytherapy on MRI. Preclinical in vitro phantom studies and in vivo canine studies are needed to further optimize MRI sequencing techniques to facilitate MRI-based dosimetry.

Frank, Steven J. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)], E-mail: sjfrank@mdanderson.org; Stafford, R. Jason; Bankson, James A. [Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Li Chun [Department of Experimental Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Swanson, David A. [Department of Urology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Kudchadker, Rajat J. [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Martirosyan, Karen S. [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX (United States)

2008-05-01T23:59:59.000Z

50

Progress in MRI Contrast Agents  

Science Conference Proceedings (OSTI)

... There has been enormous improvement in MRI technology over the ... embedded with iron oxide, and placed in a 7 tesla nuclear magnetic resonance ...

2013-03-12T23:59:59.000Z

51

Cranial anatomy and detection of ischemic stroke in the cat by nuclear magnetic resonance imaging  

SciTech Connect

Proton nuclear magnetic resonance (NMR) images of cat heads were obtained using a small, experimental imaging system. As a prelude to the study of experimental ischemic brain infarction, the normal cat head was imaged for identification of anatomical features. Images of one cat which had undergone ligation of the middle cerebral artery three weeks previously showed brain changes associated with chronic ischemic stroke and compared favorably with findings on computed tomography (CT). The NMR images have millimetric spatial resolution. NMR parameters inherent in the tissues provide intensity variations and are sufficiently sensitive to yield contrast resolution surpassing that of CT.

Buonanno, F.S.; Pykett, I.L.; Kistler, J.P.; Vielma, J.; Brady, T.J.; Hinshaw, W.S.; Goldman, M.R.; Newhouse, J.H.; Pohost, G.M.

1982-04-01T23:59:59.000Z

52

fMRI assessment of small animals' phobia using virtual reality as stimulus  

Science Conference Proceedings (OSTI)

Up to now, still images or videos of real animals have been used in functional Magnetic Resonance Imaging (fMRI) protocols to evaluate brain activations associated to small animals' phobia. Our aim in the present work is to evaluate the use of virtual ... Keywords: clinical assessment, neuroimaging, small animals' phobia, virtual reality

Miriam Clemente; Beatriz Rey; Mariano Alcañiz; Aina Rodríguez-Pujadas; Alfonso Barros-Loscertales; César Ávila; Juani Bretón-López; Cristina Botella; Rosa M. Baños

2013-05-01T23:59:59.000Z

53

High Field Magnetic Resonance Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

HFMRF Overview HFMRF Overview Section 2-3-1 High Field Magnetic Resonance Facility The High Field Magnetic Resonance Facility (HFMRF) focuses a significant portion of its research on developing a fundamental, molecular-level understanding of biochemical and biological systems and their response to environmental effects. A secondary focus is materials science, including catalysis and chemical mechanisms and processes. Staff and science consultants within this facility offer expertise in the areas of structural biology, solid-state materials characterization, and magnetic resonance imaging (MRI) techniques. Research activities in the HFMRF include: * structure determination of large molecular assemblies such as protein-DNA (normal and damaged DNA) and protein-RNA complexes

54

Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials  

DOE Patents (OSTI)

An ultra-low magnetic field NMR system can non-invasively examine containers. Database matching techniques can then identify hazardous materials within the containers. Ultra-low field NMR systems are ideal for this purpose because they do not require large powerful magnets and because they can examine materials enclosed in conductive shells such as lead shells. The NMR examination technique can be combined with ultra-low field NMR imaging, where an NMR image is obtained and analyzed to identify target volumes. Spatial sensitivity encoding can also be used to identify target volumes. After the target volumes are identified the NMR measurement technique can be used to identify their contents.

Kraus, Robert H. (Los Alamos, NM); Matlashov, Andrei N. (Los Alamos, NM); Espy, Michelle A. (Los Alamos, NM); Volegov, Petr L. (Los Alamos, NM)

2010-03-30T23:59:59.000Z

55

Detecting tumor responses to treatment using hyperpolarized 13C magnetic resonance spectroscopic imaging  

E-Print Network (OSTI)

- labeled bicarbonate. Nature 2008, 453:940-943. doi:10.1038/nrc2289 Cite this article as: Brindle: Detecting tumor responses to treatment using hyperpolarized 13C magnetic resonance spectroscopic imaging. BMC Proceedings 2010 4(Suppl 2):O24. Correspondence...

2010-09-24T23:59:59.000Z

56

Method and apparatus for molecular imaging using X-rays at resonance wavelengths  

DOE Patents (OSTI)

Holographic X-ray images are produced representing the molecular structure of a microscopic object, such as a living cell, by directing a beam of coherent X-rays upon the object to produce scattering of the X-rays by the object, producing interference on a recording medium between the scattered X-rays from the object and unscattered coherent X-rays and thereby producing holograms on the recording surface, and establishing the wavelength of the coherent X-rays to correspond with a molecular resonance of a constituent of such object and thereby greatly improving the contrast, sensitivity and resolution of the holograms as representations of molecular structures involving such constituent. For example, the coherent X-rays may be adjusted to the molecular resonant absorption line of nitrogen at about 401.3 eV to produce holographic images featuring molecular structures involving nitrogen.

Chapline, Jr., George F. (Alamo, CA)

1985-01-01T23:59:59.000Z

57

Minute Effects of Sex on the Aging Brain: A Multisample Magnetic Resonance Imaging Study of Healthy Aging and Alzheimer's Disease  

E-Print Network (OSTI)

Age is associated with substantial macrostructural brain changes. While some recent magnetic resonance imaging studies have reported larger age effects in men than women, others find no sex differences. As brain morphometry ...

Fjell, Anders M.

58

Aircraft-based Radiometric Imaging of Tropospheric Temperature and Precipitation Using the 118.75-GHz Oxygen Resonance  

Science Conference Proceedings (OSTI)

Passive microwave imagine of O2emissions using the 118.75-GHz(1?) resonance has been investigated for tropospheric and stratosphere remote sensing of atmospheric temperature and precipitation. An imaging millimeter-wave spectrometer (MTS) using ...

A. J. Gasiewski; J. W. Barrett; P. G. Bonanni; D. H. Staelin

1990-07-01T23:59:59.000Z

59

Integrated microchip incorporating atomic magnetometer and microfluidic channel for NMR and MRI  

DOE Patents (OSTI)

An integral microfluidic device includes an alkali vapor cell and microfluidic channel, which can be used to detect magnetism for nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Small magnetic fields in the vicinity of the vapor cell can be measured by optically polarizing and probing the spin precession in the small magnetic field. This can then be used to detect the magnetic field of in encoded analyte in the adjacent microfluidic channel. The magnetism in the microfluidic channel can be modulated by applying an appropriate series of radio or audio frequency pulses upstream from the microfluidic chip (the remote detection modality) to yield a sensitive means of detecting NMR and MRI.

Ledbetter, Micah P. (Oakland, CA); Savukov, Igor M. (Los Alamos, NM); Budker, Dmitry (El Cerrito, CA); Shah, Vishal K. (Plainsboro, NJ); Knappe, Svenja (Boulder, CO); Kitching, John (Boulder, CO); Michalak, David J. (Berkeley, CA); Xu, Shoujun (Houston, TX); Pines, Alexander (Berkeley, CA)

2011-08-09T23:59:59.000Z

60

Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients  

SciTech Connect

Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.

Frederick, B.deB. [California Univ., Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Development of Nuclear Magnetic Resonance Imaging/spectroscopy for improved petroleum recovery. Final report  

SciTech Connect

The overall objectives of this program are to develop and apply Nuclear Magnetic Resonance Imaging (NMRI) and CT X-Ray Scanning methods for determining rock, fluid, and petrophysical properties and for fundamental studies of multiphase flow behavior in porous media. Specific objectives are divided into four subtasks: (1) development of NMRI and CT scanning for the determination of rock-fluid and petrophysical properties; (2) development of NMRI and CT scanning for characterizing conventional multiphase displacement processes; (3) development of NMR and CT scanning for characterizing dispersed phase processes; and (4) miscible displacement studies.

Barrufet, M.A.; Flumerfelt, F.W.; Walsh, M.P.; Watson, A.T.

1994-04-01T23:59:59.000Z

62

Feature-based fusion of medical imaging data  

Science Conference Proceedings (OSTI)

The acquisition of multiple brain imaging types for a given study is a very common practice. There have been a number of approaches proposed for combining or fusing multitask or multimodal information. These can be roughly divided into those that attempt ... Keywords: Data fusion, EEG, functional magnetic resonance imaging (fMRI), independent component analysis (ICA), multivariate data analysis

Vince D. Calhoun; Tülay Adali

2009-09-01T23:59:59.000Z

63

In Vivo Near-Infrared Spectroscopy and Magnetic Resonance Imaging Monitoring of Tumor Response to Combretastatin A-4-Phosphate Correlated With Therapeutic Outcome  

Science Conference Proceedings (OSTI)

Purpose: To develop a combination treatment consisting of combretastatin A-4-phosphate (CA4P) with radiation based on tumor oxygenation status. Methods and Materials: In vivo near-infrared spectroscopy (NIRS) and diffusion-weighted (DW) magnetic resonance imaging (MRI) were applied to noninvasively monitor changes in tumor blood oxygenation and necrosis induced by CA4P (30 mg/kg) in rat mammary 13762NF adenocarcinoma, and the evidence was used to optimize combinations of CA4P and radiation treatment (a single dose of 5 Gy). Results: NIRS showed decreasing concentrations of tumor vascular oxyhemoglobin and total hemoglobin during the first 2 h after CA4P treatment, indicating significant reductions in tumor blood oxygenation and perfusion levels (p < 0.001). Twenty-four hours later, in response to oxygen inhalation, significant recovery was observed in tumor vascular and tissue oxygenation according to NIRS and pimonidazole staining results, respectively (p < 0.05). DW MRI revealed significantly increased water diffusion in tumors measured by apparent diffusion coefficient at 24 h (p < 0.05), suggesting that CA4P-induced central necrosis. In concordance with the observed tumor oxygen dynamics, we found that treatment efficacy depended on the timing of the combined therapy. The most significant delay in tumor growth was seen in the group of tumors treated with radiation while the rats breathed oxygen 24 h after CA4P administration. Conclusions: Noninvasive evaluation of tumor oxygen dynamics allowed us to rationally enhance the response of syngeneic rat breast tumors to combined treatment of CA4P with radiation.

Zhao Dawen, E-mail: Dawen.Zhao@UTSouthwestern.ed [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Chang Chenghui [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Kim, Jae G.; Liu Hanli [Joint Program in Biomedical Engineering, University of Texas Arlington and University of Texas Southwestern Medical Center, Arlington, Texas (United States); Mason, Ralph P. [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Joint Program in Biomedical Engineering, University of Texas Arlington and University of Texas Southwestern Medical Center, Arlington, Texas (United States)

2011-06-01T23:59:59.000Z

64

Image-Based Monitoring of Magnetic Resonance-Guided Thermoablative Therapies for Liver Tumors  

SciTech Connect

Minimally invasive treatment options for liver tumor therapy have been increasingly used during the last decade because their benefit has been proven for primary and inoperable secondary liver tumors. Among these, radiofrequency ablation has gained widespread consideration. Optimal image-guidance offers precise anatomical information, helps to position interventional devices, and allows for differentiation between already-treated and remaining tumor tissue. Patient safety and complete ablation of the entire tumor are the overriding objectives of tumor ablation. These may be achieved most elegantly with magnetic resonance (MR)-guided therapy, where monitoring can be performed based on precise soft-tissue imaging and additional components, such as diffusion-weighted imaging and temperature mapping. New MR scanner types and newly developed sequence techniques have enabled MR-guided intervention to move beyond the experimental phase. This article reviews the current role of MR imaging in guiding radiofrequency ablation. Signal characteristics of primary and secondary liver tumors are identified, and signal alteration during therapy is described. Diffusion-weighted imaging (DWI) and temperature mapping as special components of MR therapy monitoring are introduced. Practical information concerning coils, sequence selection, and parameters, as well as sequence gating, is given. In addition, sources of artifacts are identified and techniques to decrease them are introduced, and the characteristic signs of residual tumor in T1-, T2-, and DWI are described. We hope to enable the reader to choose MR sequences that allow optimal therapy monitoring depending on the initial signal characteristics of the tumor as well as its size and location in the liver.

Rempp, Hansjoerg, E-mail: hansjoerg.rempp@med.uni-tuebingen.de; Clasen, Stephan [Eberhard Karls University of Tuebingen, Department of Diagnostic and Interventional Radiology (Germany); Pereira, Philippe L. [SLK-Kliniken, Clinic for Radiology, Nuclear Medicine, and Minimal Invasive Therapies (Germany)

2012-12-15T23:59:59.000Z

65

Diffusion-Weighted Magnetic Resonance Imaging in Monitoring Rectal Cancer Response to Neoadjuvant Chemoradiotherapy  

SciTech Connect

Purpose: To prospectively monitor the response in patients with locally advanced nonmucinous rectal cancer after chemoradiotherapy (CRT) using diffusion-weighted magnetic resonance imaging. The histopathologic finding was the reference standard. Methods and Materials: The institutional review board approved the present study. A total of 62 patients (43 men and 19 women; mean age, 64 years; range, 28-83) provided informed consent. T{sub 2}- and diffusion-weighted magnetic resonance imaging scans (b value, 0 and 1,000 mm{sup 2}/s) were acquired before, during (mean 12 days), and 6-8 weeks after CRT. We compared the median apparent diffusion coefficients (ADCs) between responders and nonresponders and examined the associations with the Mandard tumor regression grade (TRG). The postoperative nodal status (ypN) was evaluated. The Mann-Whitney/Wilcoxon two-sample test was used to evaluate the relationships among the pretherapy ADCs, extramural vascular invasion, early percentage of increases in ADCs, and preoperative ADCs. Results: Low pretreatment ADCs (<1.0 Multiplication-Sign 10{sup -3}mm{sup 2}/s) were correlated with TRG 4 scores (p = .0011) and associated to extramural vascular invasion with ypN+ (85.7% positive predictive value for ypN+). During treatment, the mean percentage of increase in tumor ADC was significantly greater in the responders than in the nonresponders (p < .0001) and a >23% ADC increase had a 96.3% negative predictive value for TRG 4. In 9 of 16 complete responders, CRT-related tumor downsizing prevented ADC evaluations. The preoperative ADCs were significantly different (p = .0012) between the patients with and without downstaging (preoperative ADC {>=}1.4 Multiplication-Sign 10{sup -3}mm{sup 2}/s showed a positive and negative predictive value of 78.9% and 61.8%, respectively, for response assessment). The TRG 1 and TRG 2-4 groups were not significantly different. Conclusion: Diffusion-weighted magnetic resonance imaging seems to be a promising tool for monitoring the response to CRT.

Barbaro, Brunella, E-mail: bbarbaro@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy); Vitale, Renata; Valentini, Vincenzo; Illuminati, Sonia [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy); Vecchio, Fabio M. [Department of Pathology, Catholic University School of Medicine, Rome (Italy); Rizzo, Gianluca [Department of Surgery, Catholic University School of Medicine, Rome (Italy); Gambacorta, Maria Antonietta [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy); Coco, Claudio; Crucitti, Antonio; Persiani, Roberto; Sofo, Luigi [Department of Surgery, Catholic University School of Medicine, Rome (Italy); Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy)

2012-06-01T23:59:59.000Z

66

Isotopic imaging via nuclear resonance fluorescence with laser-based Thomson radiation  

DOE Patents (OSTI)

The present invention utilizes novel laser-based, high-brightness, high-spatial-resolution, pencil-beam sources of spectrally pure hard x-ray and gamma-ray radiation to induce resonant scattering in specific nuclei, i.e., nuclear resonance fluorescence. By monitoring such fluorescence as a function of beam position, it is possible to image in either two dimensions or three dimensions, the position and concentration of individual isotopes in a specific material configuration. Such methods of the present invention material identification, spatial resolution of material location and ability to locate and identify materials shielded by other materials, such as, for example, behind a lead wall. The foundation of the present invention is the generation of quasimonochromatic high-energy x-ray (100's of keV) and gamma-ray (greater than about 1 MeV) radiation via the collision of intense laser pulses from relativistic electrons. Such a process as utilized herein, i.e., Thomson scattering or inverse-Compton scattering, produces beams having diameters from about 1 micron to about 100 microns of high-energy photons with a bandwidth of .DELTA.E/E of approximately 10E.sup.-3.

Barty, Christopher P. J. (Hayward, CA); Hartemann, Frederic V. (San Ramon, CA); McNabb, Dennis P. (Alameda, CA); Pruet, Jason A. (Brentwood, CA)

2009-07-21T23:59:59.000Z

67

Applications of MRI in Fluidics: Single Echo Acquisition MRI Toward Microfluidics  

E-Print Network (OSTI)

Microscale devices capable of manipulating fluids have potential to give rise to a paradigm shift in the fields of biology and medicine. The purpose of this research is to assess the feasibility of applying single echo acquisition (SEA) magnetic resonance imaging (MRI) to microscale fluid flow quantification. This is important because development and improvement of microfluidic devices requires the ability to accurately and non-invasively measure microscale flow. Lab-on-a-chip aims to integrate an array of chemical laboratory tools onto a single chip, utilizing microfluidic flow for mass transport. Use of microfluidics results in improved speed and efficiency and allows operations that harness physical properties unique to the microscale. Current microscale flow visualization methods rely on fluorescence, requiring optically non-opaque fluids and device boundaries. Furthermore, these methods require insertion of labeled chemicals or seed particles into the flow, which may interfere with processes under observation. MRI has an established history of non-invasively quantifying flow through opaque boundaries but is limited by its slow image acquisition rate. SEA employs a 64-channel array coil to acquire a full image with each echo, significantly improving temporal resolution. Methods involve assessing the performance of SEA flow velocimetry on a scale of several millimeters by utilizing time-of-flight techniques. By taking a series of 5 ms snapshots, quantitative velocity information is obtained for laminar, transitional, and turbulent flow with Reynolds numbers ranging from 100 to 1200. Findings show that the turbulent eddies are visible and velocity information can be extracted from images, which means that SEA can accurately asses flow at the millimeter scale. In addition, SEA allows visualization of turbulent flow not accessible to standard MRI velocimetry techniques. It is concluded that SEA could be adapted as new tool for non-invasive quantification of optically inaccessible flow. Implications of this are that through integrated radio frequency microcoils, SEA MRI could be adapted as a new tool to study microfluidic flow resulting in improved microfluidic devices.

Bosshard, John

2006-08-16T23:59:59.000Z

68

Role of Diffusion-Weighted Magnetic Resonance Imaging in Predicting Sensitivity to Chemoradiotherapy in Muscle-Invasive Bladder Cancer  

Science Conference Proceedings (OSTI)

Purpose: In chemoradiation (CRT)-based bladder-sparing approaches for muscle invasive bladder cancer (MIBC), patients who respond favorably to induction CRT enjoy the benefits of bladder preservation, whereas nonresponders do not. Thus, accurate prediction of CRT sensitivity would optimize patient selection for bladder-sparing protocols. Diffusion-weighted MRI (DW-MRI) is a functional imaging technique that quantifies the diffusion of water molecules in a noninvasive manner. We investigated whether DW-MRI predicts CRT sensitivity of MIBC. Methods and Materials: The study cohort consisted of 23 MIBC patients (cT2/T3 = 7/16) who underwent induction CRT consisting of radiotherapy to the small pelvis (40 Gy) with two cycles of cisplatin (20 mg/day for 5 days), followed by partial or radical cystectomy. All patients underwent DW-MRI before the initiation of treatment. Associations of apparent diffusion coefficient (ADC) values with CRT sensitivity were analyzed. The proliferative potential of MIBC was also assessed by analyzing the Ki-67 labeling index (LI) in pretherapeutic biopsy specimens. Results: Thirteen patients (57%) achieved pathologic complete response (pCR) to CRT. These CRT-sensitive MIBCs showed significantly lower ADC values (median, 0.63 Multiplication-Sign 10{sup -3} mm{sup 2}/s; range, 0.43-0.77) than CRT-resistant (no pCR) MIBCs (median, 0.84 Multiplication-Sign 10{sup -3} mm{sup 2}/s; range, 0.69-1.09; p = 0.0003). Multivariate analysis identified ADC value as the only significant and independent predictor of CRT sensitivity (p < 0.0001; odds ratio per 0.001 Multiplication-Sign 10{sup -3} mm{sup 2}/s increase, 1.03; 95% confidence interval, 1.01-1.08). With a cutoff ADC value at 0.74 Multiplication-Sign 10{sup -3} mm{sup 2}/s, sensitivity/specificity/accuracy in predicting CRT sensitivity was 92/90/91%. Ki-67 LI was significantly higher in CRT-sensitive MIBCs (p = 0.0005) and significantly and inversely correlated with ADC values ({rho} = -0.67, p = 0.0007). Conclusions: DW-MRI is a potential biomarker for predicting CRT sensitivity in MIBC. DW-MRI may be useful to optimize patient selection for CRT-based bladder-sparing approaches.

Yoshida, Soichiro [Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo (Japan); Koga, Fumitaka, E-mail: f-koga.uro@tmd.ac.jp [Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo (Japan); Kobayashi, Shuichiro [Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo (Japan); Ishii, Chikako; Tanaka, Hiroshi [Department of Radiology, Ochanomizu Surugadai Clinic, Tokyo (Japan); Tanaka, Hajime; Komai, Yoshinobu; Saito, Kazutaka; Masuda, Hitoshi; Fujii, Yasuhisa; Kawakami, Satoru; Kihara, Kazunori [Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo (Japan)

2012-05-01T23:59:59.000Z

69

2-3 High Field Magnetic Resonance Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

HFMRF Overview HFMRF Overview High Field Magnetic Resonance Facility A significant portion of research conducted in the High Field Magnetic Resonance Facility (HFMRF) focuses on developing a fundamental, molecular-level understanding of biochemi- cal and biological systems and their response to environmental effects. A secondary focus is in materials science and catalysis and the chemical mechanisms and processes that operate in these areas. Resident and matrixed research staff within this facility offer expertise in the areas of structural biology, solid-state materials characterization, and magnetic resonance imaging (MRI) techniques. Instrumentation & Capabilities NMR * 900-MHz NMR (operational in 2004) * 800-MHz NMR * 750-MHz NMR * 600-MHz NMR (2 systems)

70

Nuclear magnetic resonance imaging and analysis for determination of porous media properties  

E-Print Network (OSTI)

Advanced nuclear magnetic resonance (NMR) imaging methodologies have been developed to determine porous media properties associated with fluid flow processes. This dissertation presents the development of NMR experimental and analysis methodologies, called NMR probes, particularly for determination of porosity, permeability, and pore-size distributions of porous media while the developed methodologies can be used for other properties. The NMR relaxation distribution can provide various information about porous systems having NMR active nuclei. The determination of the distribution from NMR relaxation data is an ill-posed inverse problem that requires special care, but conventionally the problem has been solved by ad-hoc methods. We have developed a new method based on sound statistical theory that suitably implements smoothness and equality/inequality constraints. This method is used for determination of porosity distributions. A Carr-Purcell-Meiboom-Gill (CPMG) NMR experiment is designed to measure spatially resolved NMR relaxation data. The determined relaxation distribution provides the estimate of intrinsic magnetization which, in turn, is scaled to porosity. A pulsed-field-gradient stimulated-echo (PFGSTE) NMR velocity imaging experiment is designed to measure the superficial average velocity at each volume element. This experiment measures velocity number distributions as opposed to the average phase shift, which is conventionally measured, to suitably quantify the velocities within heterogeneous porous media. The permeability distributions are determined by solving the inverse problem formulated in terms of flow models and the velocity data. We present new experimental designs associated with flow conditions to enhance the accuracy of the estimates. Efforts have been put forth to further improve the accuracy by introducing and evaluating global optimization methods. The NMR relaxation distribution can be scaled to a pore-size distribution once the surface relaxivity is known. We have developed a new method, which avoids limitations on the range of time for which data may be used, to determine surface relaxivity by the PFGSTE NMR diffusion experiment.

Uh, Jinsoo

2005-12-01T23:59:59.000Z

71

Discrete magic angle turning system, apparatus, and process for in situ magnetic resonance spectroscopy and imaging  

DOE Patents (OSTI)

Described are a "Discrete Magic Angle Turning" (DMAT) system, devices, and processes that combine advantages of both magic angle turning (MAT) and magic angle hopping (MAH) suitable, e.g., for in situ magnetic resonance spectroscopy and/or imaging. In an exemplary system, device, and process, samples are rotated in a clockwise direction followed by an anticlockwise direction of exactly the same amount. Rotation proceeds through an angle that is typically greater than about 240 degrees but less than or equal to about 360 degrees at constant speed for a time applicable to the evolution dimension. Back and forth rotation can be synchronized and repeated with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. The design permits tubes to be inserted into the sample container without introducing plumbing interferences, further allowing control over such conditions as temperature, pressure, flow conditions, and feed compositions, thus permitting true in-situ investigations to be carried out.

Hu, Jian Zhi (Richland, WA); Sears, Jr., Jesse A. (Kennewick, WA); Hoyt, David W. (Richland, WA); Wind, Robert A. (Kennewick, WA)

2009-05-19T23:59:59.000Z

72

Radiation-Induced Damage to Microstructure of Parotid Gland: Evaluation Using High-Resolution Magnetic Resonance Imaging  

SciTech Connect

Purpose: To elucidate the radiation-induced damage to the microstructure of the parotid gland using high-resolution magnetic resonance imaging. Methods and Materials: High-resolution magnetic resonance imaging of the parotid gland was performed before radiotherapy (RT) and during the RT period or {<=}3 weeks after RT completion for 12 head-and-neck cancer patients using a 1.5-T scanner with a microscopy coil. The maximal cross-sectional area of the gland was evaluated, and changes in the internal architecture of the gland were assessed both visually and quantitatively. Results: Magnetic resonance images were obtained at a median parotid gland dose of 36 Gy (range, 11-64). According to the quantitative analysis, the maximal cross-sectional area of the gland was reduced, the width of the main duct was narrowed, and the intensity ratio of the main duct lumen to background was significantly decreased after RT (p <.0001). According to the visual assessment, the width of the main duct tended to narrow and the contrast of the duct lumen tended to be decreased, but no significant differences were noted. The visibility of the duct branches was unclear in 10 patients (p = .039), and the septum became dense in 11 patients (p = .006) after RT. Conclusion: High-resolution magnetic resonance imaging is a noninvasive method of evaluating radiation-induced changes to the internal architecture of the parotid gland. Morphologic changes in the irradiated parotid gland were demonstrated during the RT course even when a relatively small dose was delivered to the gland.

Kan, Tomoko, E-mail: tkan@grape.med.tottori-u.ac.j [Department of Radiology, Tottori University Faculty of Medicine, Yonago, Tottori (Japan); Kodani, Kazuhiko; Michimoto, Koichi; Fujii, Shinya; Ogawa, Toshihide [Department of Radiology, Tottori University Faculty of Medicine, Yonago, Tottori (Japan)

2010-07-15T23:59:59.000Z

73

A survey of prostate segmentation methodologies in ultrasound, magnetic resonance and computed tomography images  

Science Conference Proceedings (OSTI)

Prostate segmentation is a challenging task, and the challenges significantly differ from one imaging modality to another. Low contrast, speckle, micro-calcifications and imaging artifacts like shadow poses serious challenges to accurate prostate segmentation ... Keywords: CT images, MR images, Prostate gland segmentation methods, TRUS images

Soumya Ghose; Arnau Oliver; Robert Martí; Xavier Lladó; Joan C. Vilanova; Jordi Freixenet; Jhimli Mitra; DéSiré Sidibé; Fabrice Meriaudeau

2012-10-01T23:59:59.000Z

74

Squid detected NMR and MRI at ultralow fields  

DOE Patents (OSTI)

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Clarke, John (Berkeley, CA); McDermott, Robert (Louisville, CO); Pines, Alexander (Berkeley, CA); Trabesinger, Andreas Heinz (CH-8006 Zurich, CH)

2007-05-15T23:59:59.000Z

75

Squid detected NMR and MRI at ultralow fields  

DOE Patents (OSTI)

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Clarke, John (Berkeley, CA); Pines, Alexander (Berkeley, CA); McDermott, Robert F. (Monona, WI); Trabesinger, Andreas H. (London, GB)

2008-12-16T23:59:59.000Z

76

MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization  

SciTech Connect

The power of magnetic resonance imaging (MRI) is its ability to image the internal structure of optically opaque samples and provide detailed maps of a variety of important parameters, such as density, diffusion, velocity and temperature. However, one of the fundamental limitations of this technique is its inherent low sensitivity. For example, the low signal to noise ratio (SNR) is particularly problematic for imaging gases in porous materials due to the low density of the gas and the large volume occluded by the porous material. This is unfortunate, as many industrially relevant chemical reactions take place at gas-surface interfaces in porous media, such as packed catalyst beds. Because of this severe SNR problem, many techniques have been developed to directly increase the signal strength. These techniques work by manipulating the nuclear spin populations to produce polarized} (i.e., non-equilibrium) states with resulting signal strengths that are orders of magnitude larger than those available at thermal equilibrium. This dissertation is concerned with an extension of a polarization technique based on the properties of parahydrogen. Specifically, I report on the novel use of heterogeneous catalysis to produce parahydrogen induced polarization and applications of this new technique to gas phase MRI and the characterization of micro-reactors. First, I provide an overview of nuclear magnetic resonance (NMR) and how parahydrogen is used to improve the SNR of the NMR signal. I then present experimental results demonstrating that it is possible to use heterogeneous catalysis to produce parahydrogen-induced polarization. These results are extended to imaging void spaces using a parahydrogen polarized gas. In the second half of this dissertation, I demonstrate the use of parahydrogen-polarized gas-phase MRI for characterizing catalytic microreactors. Specifically, I show how the improved SNR allows one to map parameters important for characterizing the heat and mass transport in a heterogeneous catalyst bed. This is followed by appendices containing detailed information regarding the design and use of my experimental setup.

Burt, Scott R; Burt, Scott R.

2008-06-25T23:59:59.000Z

77

Magnetic Resonance Connectome Automated Pipeline  

E-Print Network (OSTI)

This manuscript presents a novel, tightly integrated pipeline for estimating a connectome, which is a comprehensive description of the neural circuits in the brain. The pipeline utilizes magnetic resonance imaging (MRI) data to produce a high-level estimate of the structural connectivity in the human brain. The Magnetic Resonance Connectome Automated Pipeline (MRCAP) is efficient and its modular construction allows researchers to modify algorithms to meet their specific requirements. The pipeline has been validated and over 200 connectomes have been processed and analyzed to date. This tool enables the prediction and assessment of various cognitive covariates, and this research is applicable to a variety of domains and applications. MRCAP will enable MR connectomes to be rapidly generated to ultimately help spur discoveries about the structure and function of the human brain.

Gray, William R; Vogelstein, Joshua T; Landman, Bennett A; Prince, Jerry L; Vogelstein, R Jacob

2011-01-01T23:59:59.000Z

78

Diffusion-Weighted Magnetic Resonance Imaging to Evaluate Major Salivary Gland Function Before and After Radiotherapy  

Science Conference Proceedings (OSTI)

Purpose: To evaluate diffusion-weighted (DW)-MRI as a noninvasive tool to investigate major salivary gland function before and after radiotherapy (RT) for head and neck cancer (HNC). Methods and Materials: DW-MRI was performed in 8 HNC patients before and after parotid-sparing RT (mean dose to the contralateral parotid gland glands were calculated. Findings were compared with salivary gland scintigraphy. Results: Before RT, the mean ADC value at rest was significantly lower in the parotid than in the submandibular glands. During the first 5 min of stimulation, the ADC value of the salivary glands showed a decrease, followed by a steady increase until a peak ADC, significantly higher than the baseline value, was reached after a median of 17 min. The baseline ADC value at rest was significantly higher after RT than before RT in the nonspared salivary glands but not in the spared parotid glands. In the contralateral parotid glands, the same response was seen as before RT. This pattern was completely lost in the nonspared glands. These results corresponded with remaining or loss of salivary function, respectively, as confirmed by salivary gland scintigraphy. Conclusions: Diffusion-weighted-MRI allows noninvasive evaluation of functional changes in the major salivary glands after RT and is a promising tool for investigating radiation-induced xerostomia.

Dirix, Piet [Department of Radiation Oncology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Campus Gasthuisberg, Leuven (Belgium)], E-mail: piet.dirix@uzleuven.be; Keyzer, Frederik de; Vandecaveye, Vincent [Department of Radiology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Campus Gasthuisberg, Leuven (Belgium); Stroobants, Sigrid [Department of Nuclear Medicine, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Campus Gasthuisberg, Leuven (Belgium); Hermans, Robert [Department of Radiology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Campus Gasthuisberg, Leuven (Belgium); Nuyts, Sandra [Department of Radiation Oncology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Campus Gasthuisberg, Leuven (Belgium)

2008-08-01T23:59:59.000Z

79

HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2002  

E-Print Network (OSTI)

Provides information relevant to the conduct and interpretation of human brain mapping studies. Provides in-depth coverage of the physics of image formation, mechanisms of image contrast, and the physiological basis for ...

Gollub, Randy L.

80

HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2004  

E-Print Network (OSTI)

Provides information relevant to the conduct and interpretation of human brain mapping studies. Provides in-depth coverage of the physics of image formation, mechanisms of image contrast, and the physiological basis for ...

Gollub, Randy L.

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81

Resolving the Impact of Biological Processes on Water Transport in Unsaturated Porous Media Through Nuclear Magnetic Resonance Micro-Imaging  

DOE Green Energy (OSTI)

The magnetic resonance microscopy (MRM) work at Montana State University has extended the imaging of a single biofilm in a 1 mm capillary reactor to correlate T2 magnetic relaxation maps displaying biofilm structure with the corresponding velocity patterns in three dimensions in a Staphylococcus epidermidis biofilm fouled square capillary. A square duct geometry is chosen to provide correlation with existing experiments and simulations, as research bioreactors tend to be of square or rectangular cross section for optical or microelectrode access. The spatially resolved velocity data provide details on the impact of biofilm induced advection on mass transport from the bulk fluid to the biofilm and through the capillary bioreactor.

Seymour, Joseph D.

2005-06-01T23:59:59.000Z

82

Evaluation of Artifacts and Distortions of Titanium Applicators on 3.0-Tesla MRI: Feasibility of Titanium Applicators in MRI-Guided Brachytherapy for Gynecological Cancer  

Science Conference Proceedings (OSTI)

Purpose: The aim of this study was to characterize the levels of artifacts and distortions of titanium applicators on 3.0-Tesla magnetic resonance imaging (MRI). Methods and Materials: Fletcher-Suit-Delclos-style tandem and ovoids (T and O) and tandem and ring applicator (T and R) were examined. The quality assurance (QA) phantoms for each applicator were designed and filled with copper sulphate solution (1.5 g/l). The artifacts were quantified with the registration of corresponding computed tomography (CT) images. A favorable MR sequence was searched in terms of artifacts. Using the sequence, the artifacts were determined. The geometric distortions induced by the applicators were quantified through each registration of CT and MRI without applicators. The artifacts of T and O were also evaluated on in vivo MRI datasets of 5 patients. Results: T1-weighted MRI with 1-mm slice thickness was found as a favorable MR sequence. Applying the sequence, the artifacts at the tandem tip of T and O and T and R were determined as 1.5 {+-} 0.5 mm in a superior direction in phantom studies. In the ovoids of T and O, we found artifacts less than 1.5 {+-} 0.5 mm. The artifacts of a T and O tandem in vivo were found as less than 2.6 {+-} 1.3 mm on T1-weighted MRI, whereas less than 6.9 {+-} 3.4 mm on T2-weighted MRI. No more than 1.2 {+-} 0.6 mm (3.0 {+-} 1.5 mm) of distortions, due to a titanium applicator, were measured on T1-weighted MRI (T2-). Conclusion: In 3.0-Tesla MRI, we found the artifact widths at the tip of tandem were less than 1.5 {+-} 0.5 mm for both T and O and T and R when using T1-weighted MRI in phantom studies. However, exclusive 3.0-Tesla MRI-guided brachytherapy planning with a titanium applicator should be cautiously implemented.

Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States); Muruganandham, Manickam; Modrick, Joseph M.; Bayouth, John E. [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States)

2011-07-01T23:59:59.000Z

83

NMR/MRI with hyperpolarized gas and high Tc SQUID  

DOE Patents (OSTI)

A method and apparatus for the detection of nuclear magnetic resonance (NMR) signals and production of magnetic resonance imaging (MRI) from samples combines the use of hyperpolarized inert gases to enhance the NMR signals from target nuclei in a sample and a high critical temperature (Tc) superconducting quantum interference device (SQUID) to detect the NMR signals. The system operates in static magnetic fields of 3 mT or less (down to 0.1 mT), and at temperatures from liquid nitrogen (77K) to room temperature. Sample size is limited only by the size of the magnetic field coils and not by the detector. The detector is a high Tc SQUID magnetometer designed so that the SQUID detector can be very close to the sample, which can be at room temperature.

Schlenga, Klaus (Eggenstein, DE); de Souza, Ricardo E. (Recife, BR); Wong-Foy, Annjoe (Berkeley, CA); Clarke, John (Berkeley, CA); Pines, Alexander (Berkeley, CA)

2000-01-01T23:59:59.000Z

84

The Resonant Retina: Exploiting Vibration Noise to Optimally Detect Edges in an Image  

Science Conference Proceedings (OSTI)

Abstract¿We show that, far from being a drawback, the ubiquitous presence of random vibrations in vision systems operating from mobile devices can advantageously be used as a fundamental tool for edge detection. Directly inspired by biology, the concept ... Keywords: Edge detection, random vibration of the optical axis, microsaccades, threshold variance estimator, Fisher information, Cramer-Rao inequality, stochastic resonance.

Max-Olivier Hongler; Yuri L. de Meneses; Antoine Beyeler; Jacques Jacot

2003-09-01T23:59:59.000Z

85

Method for nuclear magnetic resonance imaging using deuterum as a contrast agent  

DOE Patents (OSTI)

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

Kehayias, Joseph J. (Chestnut Hill, MA); Joel, Darrel D. (Setauket, NY); Adams, William H. (Eastport, NY); Stein, Harry L. (Glen Head, NY)

1990-01-01T23:59:59.000Z

86

Neutron Imaging Explored as Complementary Technique for Improving Cancer  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Imaging Explored as Complementary Technique for Improving Cancer Neutron Imaging Explored as Complementary Technique for Improving Cancer Detection August 05, 2013 Researcher Maria Cekanova analyzes the neutron radiographs of a canine breast tumor (black color in top image of monitor screen) using the software to visualize in color the various intensities of neutron transmissions through the breast tissue. ORNL and University of Tennessee collaboration now analyzing first results from neutron radiographs of cancerous tissue samples Today's range of techniques for detection of breast and other cancers include mammography, computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET), and optical imaging. Each technology has advantages and disadvantages, with limitations either

87

Nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents (OSTI)

An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio-frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

Fukushima, Eiichi (Los Alamos, NM); Roeder, Stephen B. W. (La Mesa, CA); Assink, Roger A. (Albuquerque, NM); Gibson, Atholl A. V. (Bryan, TX)

1986-01-01T23:59:59.000Z

88

Value of Diffusion-Weighted Magnetic Resonance Imaging for Prediction and Early Assessment of Response to Neoadjuvant Radiochemotherapy in Rectal Cancer: Preliminary Results  

Science Conference Proceedings (OSTI)

Purpose: To evaluate diffusion-weighted magnetic resonance imaging (DWI) for response prediction before and response assessment during and early after preoperative radiochemotherapy (RCT) for locally advanced rectal cancer (LARC). Methods and Materials: Twenty patients receiving RCT for LARC underwent MRI including DWI before RCT, after 10-15 fractions and 1 to 2 weeks before surgery. Tumor volume and apparent diffusion coefficient (ADC; b-values: 0-1000 s/mm{sup 2}) were determined at all time points. Pretreatment tumor ADC and volume, tumor ADC change ( Increment ADC), and volume change ( Increment V) between pretreatment and follow-up examinations were compared with histopathologic findings after total mesorectal excision (pathologic complete response [pCR] vs. no pCR, ypT0-2 vs. ypT3-4, T-downstaging or not). The discriminatory capability of pretreatment tumor ADC and volume, Increment ADC, and Increment V for the detection of pCR was compared with receiver operating characteristics analysis. Results: Pretreatment ADC was significantly lower in patients with pCR compared with patients without (in mm{sup 2}/s: 0.94 {+-} 0.12 Multiplication-Sign 10{sup -3} vs. 1.19 {+-} 0.22 Multiplication-Sign 10{sup -3}, p = 0.003), yielding a sensitivity of 100% and specificity of 86% for detection of pCR. The volume reduction during and after RCT was significantly higher in patients with pCR compared with patients without (in %: {Delta}V{sub during}: -62 {+-} 16 vs. -33 {+-} 16, respectively, p = 0.015; and {Delta}V{sub post}: -86 {+-} 12 vs. -60 {+-} 21, p = 0.012), yielding a sensitivity of 83% and specificity of 71% for the {Delta}V{sub during} and, respectively, 83% and 86% for the {Delta}V{sub post}. The Increment ADC during ({Delta}ADC{sub during}) and after RCT ({Delta}ADC{sub post}) showed a significantly higher value in patients with pCR compared with patients without (in %: {Delta}ADC{sub during}: 72 {+-} 14 vs. 16 {+-} 12, p = 0.0006; and {Delta}ADC{sub post}: 88 {+-} 35 vs. 26 {+-} 19, p = 0.0011), yielding a sensitivity and specificity of 100% for the {Delta}ADC{sub during} and, respectively, 100% and 93% for the {Delta}ADC{sub post}. Conclusions: These initial findings indicate that DWI, using pretreatment ADC, {Delta}ADC{sub during}, and {Delta}ADC{sub post} may be useful for prediction and early assessment of pathologic response to preoperative RCT of LARC, with higher accuracy than volumetric measurements.

Lambrecht, Maarten, E-mail: maarten.lambrecht@uzleuven.be [Department of Radiation Oncology, UZ Gasthuisberg, Leuven (Belgium); Vandecaveye, Vincent; De Keyzer, Frederik [Department of Radiology, UZ Gasthuisberg, Leuven (Belgium); Roels, Sarah [Department of Radiation Oncology, UZ Gasthuisberg, Leuven (Belgium); Penninckx, Freddy [Department of Abdominal Surgery, UZ Gasthuisberg, Leuven (Belgium); Van Cutsem, Eric [Department of Digestive Oncology, UZ Gasthuisberg, Leuven (Belgium); Filip, Claus [Department of Radiology, UZ Gasthuisberg, Leuven (Belgium); Haustermans, Karin [Department of Radiation Oncology, UZ Gasthuisberg, Leuven (Belgium)

2012-02-01T23:59:59.000Z

89

Development of a flexible optical fiber based high resolution integrated PET/MRI system  

SciTech Connect

Purpose: The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET/MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce the problem, the authors newly developed flexible optical fiber bundle based block detectors and employed them for a high resolution integrated PET/MRI system. Methods: The flexible optical fiber bundle used 0.5 mm diameter, 80 cm long double clad fibers which have dual 12 mm Multiplication-Sign 24 mm rectangular inputs and a single 24 mm Multiplication-Sign 24 mm rectangular output. In the input surface, LGSO scintillators of 0.025 mol.% (decay time: {approx}31 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 5 mm) and 0.75 mol.% (decay time: {approx}46 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 6 mm) were optically coupled in depth direction to form depth-of-interaction detector, arranged in 11 Multiplication-Sign 13 matrix and optically coupled to the fiber bundle. The two inputs of the bundle are bent for 90 Degree-Sign , bound to one, and are optically coupled to a Hamamatsu 1-in. square position sensitive photomultiplier tube. Results: Light loss due to the fiber bundle could be reduced and the performance of the block detectors was improved. Eight optical fiber based block detectors (16 LGSO blocks) were arranged in a 56 mm diameter ring to form a PET system. Spatial resolution and sensitivity were 1.2 mm full-width at half-maximum and 1.2% at the central field-of-view, respectively. Sensitivity change was less than 1% for 2 Degree-Sign C temperature changes. This PET system was integrated with a 0.3 T permanent magnet MRI system which has 17 cm diameter hole at the yoke area for insertion of the PET detector ring. There was no observable interference between PET and MRI. Simultaneous imaging of PET and MRI was successfully performed for small animal studies. Conclusions: The authors confirmed that the developed high resolution PET/MRI system is promising for molecular imaging research.

Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Aoki, Masaaki; Sugiyama, Eiji; Kato, Katsuhiko; Hatazawa, Jun [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi 461-8673 (Japan); Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 565-0871 Osaka (Japan); Neomax Engineering, Takasaki 370-2115 (Japan); Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya 461-8673 (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan) and Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan)

2012-11-15T23:59:59.000Z

90

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Allan M. Cormack, Computerized Axial Tomography (CAT) Allan M. Cormack, Computerized Axial Tomography (CAT) and Magnetic Resonance Imaging (MRI) Resources with Additional Information magnetic resonance imaging system Computed axial tomography, commonly known as CAT scanning, was introduced in 1972. During a CAT scan, a large coil of x-ray tubes rotates around the patient's body, taking x-rays from all angles. A computer integrates all of these x-rays into a single, three-dimensional image on a television screen. The data can be saved on the computer. Allan M. Cormack, a high energy physicist at Tufts University, shared the 1979 Nobel Prize in Physiology and Medicine for his key work in developing the methods for CAT scanners. At the time of development, these methods were widely regarded as the most significant advance in medical radiography since the 1895 discovery of x-rays.

91

Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state.  

E-Print Network (OSTI)

in functional neuroimaging. J Cogn Neurosci 2003, 15:394-408. 35. Genovese CR, Lazar NA, Nichols T: Thresholding of statistical maps in functional neuroimaging using the false discovery rate. NeuroImage 2002, 15:870-878. 36. Vigneau M, Beaucousin V, Hervé PY...

Fernandez-Espejo, Davinia; Junque, Carme; Cruse, Damian; Bernabeu, Montserrat; Roig-Rovira, Teresa; Fabregas, Neus; Rivas, Eva; Mercader, Jose M

2010-09-03T23:59:59.000Z

92

Fast Magnetic Resonance Imaging via Adaptive Broadband Encoding of the MR Signal Content  

E-Print Network (OSTI)

signal is radiated from the sample and decays over time both via the return of the sample's magnetization decays after sample excitation. Relaxation times of the order of 1sec in human tissue make the process studies where a continu- ous series of images is required, for example in contrast bolus tracking

Edelman, Alan

93

Apparatus for preparing a solution of a hyperpolarized noble gas for NMR and MRI analysis  

DOE Patents (OSTI)

The present invention relates generally to nuclear magnetic resonance (NMR) techniques for both spectroscopy and imaging. More particularly, the present invention relates to methods in which hyperpolarized noble gases (e.g., Xe and He) are used to enhance and improve NMR and MRI. Additionally, the hyperpolarized gas solutions of the invention are useful both in vitro and in vivo to study the dynamics or structure of a system. When used with biological systems, either in vivo or in vitro, it is within the scope of the invention to target the hyperpolarized gas and deliver it to specific regions within the system.

Pines, Alexander (Berkeley, CA); Budinger, Thomas (Berkeley, CA); Navon, Gil (Ramat Gan, IL); Song, Yi-Qiao (Berkeley, CA); Appelt, Stephan (Waiblingen, DE); Bifone, Angelo (Rome, IT); Taylor, Rebecca (Berkeley, CA); Goodson, Boyd (Berkeley, CA); Seydoux, Roberto (Berkeley, CA); Room, Toomas (Albany, CA); Pietrass, Tanja (Socorro, NM)

2008-06-10T23:59:59.000Z

94

Probabilistic graphical model of SPECT/MRI  

Science Conference Proceedings (OSTI)

The combination of PET and SPECT with MRI is an area of active research at present time and will enable new biological and pathological analysis tools for clinical applications and pre-clinical research. Image processing and reconstruction in multi-modal ... Keywords: Bayesian networks, emission tomography, molecular imaging, multi-modality

Stefano Pedemonte; Alexandre Bousse; Brian F. Hutton; Simon Arridge; Sebastien Ourselin

2011-09-01T23:59:59.000Z

95

Mapping local hippocampal changes in Alzheimer's disease and normal ageing with MRI at 3 Tesla  

E-Print Network (OSTI)

Mapping local hippocampal changes in Alzheimer's disease and normal ageing with MRI at 3 Tesla and Alzheimer's disease based on high resolution MRI at 3 Tesla. T1-weighted images were acquired from 19

Thompson, Paul

96

Micromagnets Show Promise as Colorful 'Smart Tags' for MRI  

Science Conference Proceedings (OSTI)

... smart tag” capability to magnetic resonance imaging for medical diagnosis and research. The image on the right shows light scattering from grids of ...

2011-05-03T23:59:59.000Z

97

Sequence optimization to reduce velocity offsets in cardiovascular magnetic resonance volume flow quantification - A multi-vendor study  

E-Print Network (OSTI)

of interest may lead to phase-encode wraparound hinder- ing conventional background correction post-processing if still needed. Sequence development might also focus on a more fundamental level of eddy current compensation, such as sequence... and Correcting Gradient Errors in Non-Cartesian Imaging: Are Gradient Errors Linear Time-Invariant (LTI)? Magn Reson Med 2009, 62:1466-1476. 16. Bernstein MA, King KF, Zhou XHJ: Correction Gradients - Eddy Current Compensation. Handbook of MRI pulse sequences...

Rolf, Marijn P; Hofman, Mark B M; Gatehouse, Peter D; Markenroth Bloch, Karin; Heymans, Martijn W; Ebbers, Tino; Graves, Martin J; Totman, John J; Werner, Beat; Rossum, Albert C van; Kilner, Philip J; Heethaar, Rob M

2011-03-09T23:59:59.000Z

98

Modified expectation maximization algorithm for MRI segmentation  

Science Conference Proceedings (OSTI)

Magnetic Resonance Image segmentation is a fundamental task in a wide variety of computed-based medical applications that support therapy, diagnostic and medical applications. In this work, spatial information is included for estimating paramaters of ... Keywords: expectation maximization algorithm, finite mixture models, magnetic resonance imaging segmentation, spatial information

Ramiro Donoso; Alejandro Veloz; Héctor Allende

2010-11-01T23:59:59.000Z

99

Small Unilamellar Vesicles: A Platform Technology for Molecular Imaging of Brain Tumors  

SciTech Connect

Molecular imaging enables the non-invasive investigation of cellular and molecular processes. Although there are challenges to overcome, the development of targeted contrast agents to increase the sensitivity of molecular imaging techniques is essential for their clinical translation. In this study, spontaneously forming, small unilamellar vesicles (sULVs) (30 nm diameter) were used as a platform to build a bimodal (i.e., optical and magnetic resonance imaging (MRI)) targeted contrast agent for the molecular imaging of brain tumors. sULVs were loaded with a gadolinium (Gd) chelated lipid (Gd-DPTA-BOA), functionalized with targeting antibodies (anti-EGFR monoclonal and anti-IGFBP7 single domain), and incorporated a near infrared dye (Cy5.5). The resultant sULVs were characterized in vitro using small angle neutron scattering (SANS), phantom MRI and dynamic light scattering (DLS). Antibody targeted and nontargeted Gd loaded sULVs labeled with Cy5.5 were assessed in vivo in a brain tumor model in mice using time domain optical imaging and MRI. The results demonstrated that a spontaneously forming, nanosized ULVs loaded with a high payload of Gd can selectively target and image, using MR and optical imaging, brain tumor vessels when functionalized with anti-IGFBP7 single domain antibodies. The unique features of these targeted sULVs make them promising molecular MRI contrast agents.

Iqbal, U [National Research Council of Canada, Ottawa, ON, Canada; Albaghdadi, H [National Research Council of Canada, Ottawa, ON, Canada; Nieh, Mu-Ping [University of Connecticut, Storrs; Tuor, U.I [National Research Council of Canada, Calcary, AB, Canada; Mester, Z [National Research Council of Canada, Ottawa, ON, Canada; Stanimirovic, D [National Research Council of Canada, Ottawa, ON, Canada; Katsaras, John [ORNL; Abulrob, A [National Research Council of Canada, Ottawa, ON, Canada

2011-01-01T23:59:59.000Z

100

Index of /images/whole.frog/data  

NLE Websites -- All DOE Office Websites (Extended Search)

data Parent Directory Copyright.Notice FROG.IMAGES.tar MRI color.images.zip frog.data.Z frog.hd masks...

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Integration of Functional MRI and White Matter Tractography in Stereotactic Radiosurgery Clinical Practice  

Science Conference Proceedings (OSTI)

Purpose: To study the efficacy of the integration of functional magnetic resonance imaging (fMRI) and diffusion tensor imaging tractography data into stereotactic radiosurgery clinical practice. Methods and Materials: fMRI and tractography data sets were acquired and fused with corresponding anatomical MR and computed tomography images of patients with arteriovenous malformation (AVM), astrocytoma, brain metastasis, or hemangioma and referred for stereotactic radiosurgery. The acquired data sets were imported into a CyberKnife stereotactic radiosurgery system and used to delineate the target, organs at risk, and nearby functional structures and fiber tracts. Treatment plans with and without the incorporation of the functional structures and the fiber tracts into the optimization process were developed and compared. Results: The nearby functional structures and fiber tracts could receive doses of >50% of the maximum dose if they were excluded from the planning process. In the AVM case, the doses received by the Broadmann-17 structure and the optic tract were reduced to 700 cGy from 1,400 cGy and to 1,200 cGy from 2,000 cGy, respectively, upon inclusion into the optimization process. In the metastasis case, the motor cortex received 850 cGy instead of 1,400 cGy; and in the hemangioma case, the pyramidal tracts received 780 cGy instead of 990 cGy. In the astrocytoma case, the dose to the motor cortex bordering the lesion was reduced to 1,900 cGy from 2,100 cGy, and therefore, the biologically equivalent dose in three fractions was delivered instead. Conclusions: Functional structures and fiber tracts could receive high doses if they were not considered during treatment planning. With the aid of fMRI and tractography images, they can be delineated and spared.

Pantelis, Evaggelos, E-mail: vpantelis@phys.uoa.g [CyberKnife Center, Iatropolis-Magnitiki Tomografia, Athens (Greece); Medical Physics Laboratory, Medical School, University of Athens, Athens (Greece); Papadakis, Nikolaos; Verigos, Kosmas; Stathochristopoulou, Irene [CyberKnife Center, Iatropolis-Magnitiki Tomografia, Athens (Greece); Antypas, Christos [CyberKnife Center, Iatropolis-Magnitiki Tomografia, Athens (Greece); First Department of Radiology, Aretaieion Hospital, University of Athens, Athens (Greece); Lekas, Leonidas; Tzouras, Argyrios [CyberKnife Center, Iatropolis-Magnitiki Tomografia, Athens (Greece); Georgiou, Evangelos [Medical Physics Laboratory, Medical School, University of Athens, Athens (Greece); Salvaras, Nikolaos [CyberKnife Center, Iatropolis-Magnitiki Tomografia, Athens (Greece)

2010-09-01T23:59:59.000Z

102

Tagged MRI-based studies of cardiac function  

Science Conference Proceedings (OSTI)

Tagged MRI provides a potentially powerful new way to noninvasively assess the regional function of the heart. Although its potential has not yet been fully realized, due to remaining technical limitations in image acquisition and analysis, good progress ...

Leon Axel

2003-06-01T23:59:59.000Z

103

Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents (OSTI)

An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

1984-01-01T23:59:59.000Z

104

Nuclear magnetic resonance contrast agents  

DOE Patents (OSTI)

A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC.sub.16 H.sub.14 N.sub.6. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques.

Smith, Paul H. (Los Alamos, NM); Brainard, James R. (Los Alamos, NM); Jarvinen, Gordon D. (Los Alamos, NM); Ryan, Robert R. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

105

Nuclear magnetic resonance contrast agents  

DOE Patents (OSTI)

A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

1997-12-30T23:59:59.000Z

106

Near-Electrode Imager  

DOE Patents (OSTI)

An apparatus, near-electrode imager, for employing nuclear magnetic resonance imaging to provide in situ measurements of electrochemical properties of a sample as a function of distance from a working electrode. The near-electrode imager use the radio frequency field gradient within a cylindrical toroid cavity resonator to provide high-resolution nuclear magnetic resonance spectral information on electrolyte materials.

Rathke, Jerome W.; Klingler, Robert J.; Woelk, Klaus; Gerald, Rex E.,II

1999-05-01T23:59:59.000Z

107

Magnetic Resonance Flow Velocity and Temperature Mapping of a Shape Memory Polymer Foam Device  

Science Conference Proceedings (OSTI)

Interventional medical devices based on thermally responsive shape memory polymer (SMP) are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI) techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.

Small IV, W; Gjersing, E; Herberg, J L; Wilson, T S; Maitland, D J

2008-10-29T23:59:59.000Z

108

Assessment of passive cardiovascular implant devices for MRI compatibility  

Science Conference Proceedings (OSTI)

Purpose: The increasing popularity of both magnetic resonance angiography and minimally invasive cardiovascular interventional procedures has led to the requirement for the development of implant devices that not only provide for patient safety, but ... Keywords: Implant, MRI, artifact, safety, stent, valve

Edward G. Walsh; Brigitta C. Brott; Vicki Y. Johnson; Ramakrishna Venugopalan; Andreas Anayiotos

2008-09-01T23:59:59.000Z

109

Bio-Med Variable Field MRI Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Bio-Med Variable Field MRI Project Bio-Med Variable Field MRI Project One of the Research and Development projects currently underway is the Bio-Med magnet. Destined for use within the solenoidal field of an MRI, it is designed for use where the subject, in this case a rat, must be tracked in order to obtain an image. Typical MRIs require the subject to remain stationary, and a rat will not normally oblige when it is awake. By moving the composite field (MRI Solenoid plus Bio-Med dipole) to track the rat, it is possible to allow the rat some freedom of motion, while still imaging the brain functions. For the rapid movement typical of a rat, the Bio-Med coil magnet must be capable of very rapid changes in field. Superconducting magnets are typically not designed to allow rapid field variations. To do so typically

110

Nuclear magnetic resonance studies of macroscopic morphology and dynamics  

Science Conference Proceedings (OSTI)

Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utility of a number of new and novel techniques using ideal systems primarily as a proof of principle. By taking advantage of the analogy between NMR imaging and diffraction, one may simplify the experiments necessary for characterizing the statistical properties of the sample morphology. For a sample composed of many small features, e.g. a porous medium, the NMR diffraction techniques take advantage of both the narrow spatial range and spatial isotropy of the sample`s density autocorrelation function to obtain high resolution structural information in considerably less time than that required by conventional NMR imaging approaches. The time savings of the technique indicates that NMR diffraction is capable of finer spatial resolution than conventional NMR imaging techniques. Radio frequency NMR imaging with a coaxial resonator represents the first use of cylindrically symmetric field gradients in imaging. The apparatus as built has achieved resolution at the micron level for water samples, and has the potential to be very useful in the imaging of circularly symmetric systems. The study of displacement probability densities in flow through a random porous medium has revealed the presence of features related to the interconnectedness of the void volumes. The pulsed gradient techniques used have proven successful at measuring flow properties for time and length scales considerably shorter than those studied by more conventional techniques.

Barrall, G.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Materials Science Div.

1995-09-01T23:59:59.000Z

111

A functional magnetic resonance imaging study of overt letter verbal fluency using a clustered acquisition sequence: greater anterior cingulate activation with increased task demand  

E-Print Network (OSTI)

Regional cerebral activation during a cognitive task can vary with task demand and task performance. In a functional magnetic resonance imaging study, we examined the effect of manipulating task demand on activation during verbal fluency by using “easy ” and “hard ” letters. A “clustered ” image acquisition sequence allowed overt verbal responses to be made in the absence of scanner noise which facilitated “online” measurement of task performance. Eleven righthanded, healthy male volunteers participated. Twice as many errors were produced with hard as with easy letters (20.8 ? 13.6 and 10.1 ? 10.7 % errors, respectively). For both conditions, the distribution of regional activation was comparable to that reported in studies of covert verbal fluency, but with greater engagement of subcortical areas. The hard condition was associated with greater dorsal anterior cingulate activation than the easy condition. This may reflect the greater demands of the former, particularly in terms of arousal responses with increased task difficulty and the monitoring of potential response errors. © 2002 Elsevier Science (USA)

Cynthia H. Y. Fu; Kevin Morgan; John Suckling; Steve C. R. Williams; Chris Andrew; Goparlen N. Vythelingum; Philip K. Mcguire

2002-01-01T23:59:59.000Z

112

Prognostic Value of Subclassification Using MRI in the T4 Classification Nasopharyngeal Carcinoma Intensity-Modulated Radiotherapy Treatment  

SciTech Connect

Purpose: To subclassify patients with the T4 classification nasopharyngeal carcinoma (NPC), according to the seventh edition of the American Joint Committee on Cancer staging system, using magnetic resonance imaging (MRI), and to evaluate the prognostic value of subclassification after intensity-modulated radiotherapy (IMRT). Methods and Materials: A total of 140 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated classification T4 NPC received IMRT as their primary treatment and were included in this retrospective study. T4 patients were subclassified into two grades: T4a was defined as a primary nasopharyngeal tumor with involvement of the masticator space only; and T4b was defined as involvement of the intracranial region, cranial nerves, and/or orbit. Results: The 5-year overall survival (OS) rate and distant metastasis-free survival (DMFS) rate for T4a patients (82.5% and 87.0%, respectively), were significantly higher than for T4b patients (62.6% and 66.8%; p = 0.033 and p = 0.036, respectively). The T4a/b subclassification was an independent prognostic factor for OS (hazard ratio = 2.331, p = 0.032) and DMFS (hazard ratio = 2.602, p = 0.034), and had no significant effect on local relapse-free survival. Conclusions: Subclassification of T4 patients, as T4a or T4b, using MRI according to the site of invasion, has prognostic value for the outcomes of IMRT treatment in NPC.

Chen Lei [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China)] [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China); Liu Lizhi [State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China)] [State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China); Chen Mo; Li Wenfei; Yin Wenjing [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China)] [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China); Lin Aihua [Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou (China)] [Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou (China); Sun Ying [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China)] [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China); Li Li [State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China)] [State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China); Ma Jun, E-mail: majun2@mail.sysu.edu.cn [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China)

2012-09-01T23:59:59.000Z

113

Perfusion Estimated With Rapid Dynamic Contrast-Enhanced Magnetic Resonance Imaging Correlates Inversely With Vascular Endothelial Growth Factor Expression and Pimonidazole Staining in Head-and-Neck Cancer: A Pilot Study  

Science Conference Proceedings (OSTI)

Purpose: To analyze, in a pilot study, rapidly acquired dynamic contrast-enhanced (DCE)-MRI data with a general two-compartment exchange tracer kinetic model and correlate parameters obtained with measurements of hypoxia and vascular endothelial growth factor (VEGF) expression in patients with squamous cell carcinoma of the head and neck. Methods and Materials: Eight patients were scanned before surgery. The DCE-MRI data were acquired with 1.5-s temporal resolution and analyzed using the two-compartment exchange tracer kinetic model to obtain estimates of parameters including perfusion and permeability surface area. Twelve to 16 h before surgery, patients received an intravenous injection of pimonidazole. Samples taken during surgery were used to determine the level of pimonidazole staining using immunohistochemistry and VEGF expression using quantitative real-time polymerase chain reaction. Correlations between the biological and imaging data were examined. Results: Of the seven tumors fully analyzed, those that were poorly perfused tended to have high levels of pimonidazole staining (r = -0.79, p = 0.03) and VEGF expression (r = -0.82, p = 0.02). Tumors with low permeability surface area also tended to have high levels of hypoxia (r = -0.75, p = 0.05). Hypoxic tumors also expressed higher levels of VEGF (r = 0.82, p = 0.02). Conclusions: Estimates of perfusion obtained with rapid DCE-MRI data in patients with head-and-neck cancer correlate inversely with pimonidazole staining and VEGF expression.

Donaldson, Stephanie B., E-mail: Stephanie.donaldson@physics.cr.man.ac.uk [School of Cancer and Enabling Sciences, University of Manchester, Manchester (United Kingdom) and North Western Medical Physics, The Christie, Manchester (United Kingdom); Betts, Guy [School of Cancer and Enabling Sciences, University of Manchester, Manchester (United Kingdom); Bonington, Suzanne C. [Department of Radiology, The Christie, Manchester (United Kingdom); Homer, Jarrod J. [School of Cancer and Enabling Sciences, University of Manchester, Manchester (United Kingdom); Department of Otolaryngology-Head-and-Neck Surgery, Manchester Royal Infirmary, Manchester (United Kingdom); Slevin, Nick J. [Department of Clinical Oncology, The Christie, Manchester (United Kingdom); Kershaw, Lucy E.; Valentine, Helen [School of Cancer and Enabling Sciences, University of Manchester, Manchester (United Kingdom); West, Catharine M.L. [School of Cancer and Enabling Sciences, University of Manchester, Manchester Academic Health Science Centre, Manchester (United Kingdom); Buckley, David L. [School of Cancer and Enabling Sciences, University of Manchester, Manchester (United Kindgom) and Division of Medical Physics, University of Leeds, Leeds (United Kingdom)

2011-11-15T23:59:59.000Z

114

Method of performing MRI with an atomic magnetometer  

SciTech Connect

A method and apparatus are provided for performing an in-situ magnetic resonance imaging of an object. The method includes the steps of providing an atomic magnetometer, coupling a magnetic field generated by magnetically resonating samples of the object through a flux transformer to the atomic magnetometer and measuring a magnetic resonance of the atomic magnetometer.

Savukov, Igor Mykhaylovich; Matlashov, Andrei Nikolaevich; Espy, Michelle A; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry; Zotev, Vadim Sergeyevich

2013-08-27T23:59:59.000Z

115

Method of performing MRI with an atomic magnetometer  

DOE Patents (OSTI)

A method and apparatus are provided for performing an in-situ magnetic resonance imaging of an object. The method includes the steps of providing an atomic magnetometer, coupling a magnetic field generated by magnetically resonating samples of the object through a flux transformer to the atomic magnetometer and measuring a magnetic resonance of the atomic magnetometer.

Savukov, Igor Mykhaylovich; Matlashov, Andrei Nikolaevich; Espy, Michelle A.; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry; Zotev, Vadim Sergeyevich

2012-11-06T23:59:59.000Z

116

Functional Segmentation of Renal DCE-MRI Sequences Using Vector Quantization Algorithms  

Science Conference Proceedings (OSTI)

In dynamic contrast-enhanced magnetic resonance imaging, segmentation of internal kidney structures like cortex, medulla and cavities is essential for functional assessment. To avoid fastidious and time-consuming manual segmentation, semi-automatic methods ... Keywords: Biomedical image processing, Biomedical magnetic resonance imaging, Clustering methods, Image segmentation, Image sequence analysis, Vector quantization

Béatrice Chevaillier; Damien Mandry; Jean-Luc Collette; Michel Claudon; Marie-Agnès Galloy; Olivier Pietquin

2011-08-01T23:59:59.000Z

117

Multi-Fiber Reconstruction from DW-MRI using a Continuous Mixture of von Mises-Fisher Distributions  

E-Print Network (OSTI)

Multi-Fiber Reconstruction from DW-MRI using a Continuous Mixture of von Mises-Fisher Distributions the Diffusion Weighted Magnetic Resonance (DW-MR) signal at each lattice point using a novel continuous mixture real DW-MRI data from rat brain and optic chiasm. 1. Introduction Since the first publication

Kumar, Ritwik

118

Experimental determination of the radial dose distribution in high gradient regions around {sup 192}Ir wires: Comparison of electron paramagnetic resonance imaging, films, and Monte Carlo simulations  

SciTech Connect

Purpose: The experimental determination of doses at proximal distances from radioactive sources is difficult because of the steepness of the dose gradient. The goal of this study was to determine the relative radial dose distribution for a low dose rate {sup 192}Ir wire source using electron paramagnetic resonance imaging (EPRI) and to compare the results to those obtained using Gafchromic EBT film dosimetry and Monte Carlo (MC) simulations. Methods: Lithium formate and ammonium formate were chosen as the EPR dosimetric materials and were used to form cylindrical phantoms. The dose distribution of the stable radiation-induced free radicals in the lithium formate and ammonium formate phantoms was assessed by EPRI. EBT films were also inserted inside in ammonium formate phantoms for comparison. MC simulation was performed using the MCNP4C2 software code. Results: The radical signal in irradiated ammonium formate is contained in a single narrow EPR line, with an EPR peak-to-peak linewidth narrower than that of lithium formate ({approx}0.64 and 1.4 mT, respectively). The spatial resolution of EPR images was enhanced by a factor of 2.3 using ammonium formate compared to lithium formate because its linewidth is about 0.75 mT narrower than that of lithium formate. The EPRI results were consistent to within 1% with those of Gafchromic EBT films and MC simulations at distances from 1.0 to 2.9 mm. The radial dose values obtained by EPRI were about 4% lower at distances from 2.9 to 4.0 mm than those determined by MC simulation and EBT film dosimetry. Conclusions: Ammonium formate is a suitable material under certain conditions for use in brachytherapy dosimetry using EPRI. In this study, the authors demonstrated that the EPRI technique allows the estimation of the relative radial dose distribution at short distances for a {sup 192}Ir wire source.

Kolbun, N.; Leveque, Ph.; Abboud, F.; Bol, A.; Vynckier, S.; Gallez, B. [Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Institute of Experimental and Clinical Research, Universite catholique de Louvain, Avenue Hippocrate 55, B-1200 Brussels (Belgium); Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium)

2010-10-15T23:59:59.000Z

119

Preoperative 3-Tesla Multiparametric Endorectal Magnetic Resonance Imaging Findings and the Odds of Upgrading and Upstaging at Radical Prostatectomy in Men With Clinically Localized Prostate Cancer  

Science Conference Proceedings (OSTI)

Purpose: To investigate whether 3-T esla (3T) multiparametric endorectal MRI (erMRI) can add information to established predictors regarding occult extraprostatic or high-grade prostate cancer (PC) in men with clinically localized PC. Methods and Materials: At a single academic medical center, this retrospective study's cohort included 118 men with clinically localized PC who underwent 3T multiparametric erMRI followed by radical prostatectomy, from 2008 to 2011. Multivariable logistic regression analyses in all men and in 100 with favorable-risk PC addressed whether erMRI evidence of T3 disease was associated with prostatectomy T3 or Gleason score (GS) 8-10 (in patients with biopsy GS {Tesla multiparametric erMRI in men with favorable-risk PC provides information beyond that contained in known preoperative predictors about the presence of occult extraprostatic and/or high-grade PC. If validated in additional studies, this information can be used to counsel men planning to undergo radical prostatectomy or radiation therapy about the possible need for adjuvant radiation therapy or the utility of adding hormone therapy, respectively.

Hegde, John V. [Harvard Medical School, Boston, Massachusetts (United States) [Harvard Medical School, Boston, Massachusetts (United States); Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts (United States); Chen, Ming-Hui [Department of Statistics, University of Connecticut, Storrs, Connecticut (United States)] [Department of Statistics, University of Connecticut, Storrs, Connecticut (United States); Mulkern, Robert V. [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts (United States) [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts (United States); Department of Radiology, Children's Hospital Boston, Boston, Massachusetts (United States); Fennessy, Fiona M. [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts (United States) [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts (United States); Department of Imaging, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); D'Amico, Anthony V. [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Tempany, Clare M.C., E-mail: ctempany@bwh.harvard.edu [Division of MRI, Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts (United States)

2013-02-01T23:59:59.000Z

120

Probing brain connectivity by combined analysis of diffusion MRI tractography and electrocorticography  

Science Conference Proceedings (OSTI)

Electrocorticography (ECoG) allows for measurement of task-related local field potentials directly from cortex in neurosurgical patients. Diffusion tensor imaging (DTI) tractography is an MRI technique that allows for reconstruction of brain white matter ... Keywords: Delay activity, Diffusion-weighted MRI, Electrocorticography, Epilepsy, Inferior fronto-occipital fasciculus, Tractography, Working memory

Kathrin Tertel; Nitin Tandon; Timothy M. Ellmore

2011-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Print Imaging Print The wavelengths of soft x-ray photons (1-15 nm) are very well matched to the creation of "nanoscopes" capable of probing the interior structure of biological cells and inorganic mesoscopic systems.Topics addressed by soft x-ray imaging techniques include cell biology, nanomagnetism, environmental science, and polymers. The tunability of synchrotron radiation is absolutely essential for the creation of contrast mechanisms. Cell biology CAT scans are performed in the "water window" (300-500 eV). Nanomagnetism studies require the energy range characteristic of iron, cobalt, and nickel (600-900 eV). Mid- and far-infrared (energies below 1 eV) microprobes using synchrotron radiation are being used to address problems such as chemistry in biological tissues, chemical identification and molecular conformation, environmental biodegradation, mineral phases in geological and astronomical specimens, and electronic properties of novel materials. Infrared synchrotron radiation is focused through, or reflected from, a small spot on the specimen and then analyzed using a spectrometer. Tuning to characteristic vibrational frequencies serves as a sensitive fingerprint for molecular species. Images of the various species are built up by raster scanning the specimen through the small illuminated spot.

122

Anisotropy Characterization of I-125 Seed with Attached Encapsulated Cobalt Chloride Complex Contrast Agent Markers for MRI-Based Prostate Brachytherapy  

Science Conference Proceedings (OSTI)

We have developed a novel MRI marker for prostate brachytherapy. The purpose of this study was to evaluate the changes in anisotropy when cobalt chloride complex contrast agent encapsulated contrast agent markers (C4-ECAM) were placed adjacent to an iodine-125 (I-125) titanium seed, and to verify that the C4-ECAMs were visible on magnetic resonance imaging (MRI) after radiation exposure. Two C4-ECAMs were verified to be MRI visible in a phantom before radiation exposure. The C4-ECAMs were then attached to each end of a 12.7-U (10-mCi) I-125 titanium seed in a polymer tube. Anisotropy was measured and analyzed with the seed alone and with attached C4-ECAMs by suspending thermoluminescent dosimeters in a water phantom in 2 circles surrounding the radioactive source with radius of 1 or 2 cm. A T1-weighted MRI evaluation of C4-ECAMs was then performed after exposure to the amount of radiation typically delivered during 1 month of prostate brachytherapy. Measured values of the anisotropy function F(r, {theta}) for the I-125 seed with and without the C4-ECAMs were mutually statistically indistinguishable (standard error of the mean <4.2%) and agreed well with published TG-43 values for the bare seed. As expected, the anisotropy function {phi}{sub an}(r) for the 2 datasets (with and without C4-ECAMs) derived from the measured F(r, {theta}) did not exhibit statistically measurable difference. Both datasets showed agreement with the published TG-43 {phi}{sub an}(r) for the bare seed. The C4-ECAMs were well visualized by MRI after 1 month of radiation exposure. There were no changes in anisotropy when the C4-ECAMs were placed next to an I-125 radioactive seed, and the C4-ECAMs were visualized after radiation exposure.

Frank, Steven J., E-mail: sjfrank@mdanderson.or [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Tailor, Ramesh C.; Kudchadker, Rajat J. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Martirosyan, Karen S. [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX (United States); Stafford, R. Jason; Elliott, Andrew M. [Department of Imaging Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Swanson, David A. [Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Sing, David; Choi, Jonathan [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Mourtada, Firas; Ibbott, Geoffrey S. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2011-07-01T23:59:59.000Z

123

Novel motor design for rotating anode x-ray tubes operating in the fringe field of a magnetic resonance imaging system  

SciTech Connect

Purpose: Using hybrid x-ray/MR (XMR) systems for image guidance during interventional procedures could enhance the diagnosis and treatment of neurologic, oncologic, cardiovascular, and other disorders. The authors propose a close proximity hybrid system design in which a C-arm fluoroscopy unit is placed immediately adjacent to the solenoid magnet of a MR system with a minimum distance of 1.2 m between the x-ray and MR imaging fields of view. Existing rotating anode x-ray tube designs fail within MR fringe field environments because the magnetic fields alter the electron trajectories in the x-ray tube and act as a brake on the induction motor, reducing the rotation speed of the anode. In this study the authors propose a novel motor design that avoids the anode rotation speed reduction. Methods: The proposed design replaces the permanent magnet stator found in brushed dc motors with the radial component of the MR fringe field. The x-ray tube is oriented such that the radial component of the MR fringe field is orthogonal to the cathode-anode axis. Using a feedback position sensor and the support bearings as electrical slip rings, the authors use electrical commutation to eliminate the need for mechanical brushes and commutators. A vacuum compatible prototype of the proposed motor design was assembled, and its performance was evaluated at various operating conditions. The prototype consisted of a 3.1 in. diameter anode rated at 300 kHU with a ceramic rotor that was 5.6 in. in length and had a 2.9 in. diameter. The material chosen for all ceramic components was MACOR, a machineable glass ceramic developed by Corning Inc. The approximate weight of the entire assembly was 1750 g. The maximum rotation speed, angular acceleration, and acceleration time of the motor design were investigated, as well as the dependence of these parameters on rotor angular offset, magnetic field strength, and field orientation. The resonance properties of the authors' assembly were also evaluated to determine its stability during acceleration, and a pulse width modulation algorithm was implemented to control the rotation speed of the motor. Results: At a magnetic flux density of 41 mT orthogonal to the axis of rotation (on the lower end of the expected flux density in the MR suite) the maximum speed of the motor was found to be 5150 revolutions per minute (rpm). The acceleration time necessary to reach 3000 rpm was found to be approximately 10 s at 59 mT. The resonance frequency of the assembly with the anode attached was 1310 rpm (21.8 Hz) which is far below the desired operating speeds. Pulse width modulation provides an effective method to control the speed of the motor with a resolution of 100 rpm. Conclusions: The proposed design can serve as a direct replacement to the conventional induction motor used in rotating anode x-ray tubes. It does not suffer from a reduced rotation speed when operating in a MR environment. The presence of chromic steel bearings in the prototype prevented testing at the higher field strengths, and future iterations of the design could eliminate this shortcoming. The prototype assembly demonstrates proof of concept of the authors' design and overcomes one of the major obstacles for a MR compatible rotating anode x-ray tube.

Lillaney, Prasheel; Pelc, Norbert [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States); Shin Mihye [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Hinshaw, Waldo; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Bennett, N. Robert [Department of Radiology, Stanford University, Stanford, California 94305 and Qualcomm MEMS Technologies, San Jose, California 95134 (United States)

2013-02-15T23:59:59.000Z

124

A fast and efficient method for compressing fMRI data sets  

Science Conference Proceedings (OSTI)

We present a new lossless compression method named FTTcoder, which compresses images and 3d sequences collected during a typical functional MRI experiment. The large data sets involved in this popular medical application necessitate novel compression ...

Fabian J. Theis; Toshihisa Tanaka

2005-09-01T23:59:59.000Z

125

New Methods in Motion Tracking to Generate Motion-Corrected Tomographic Images  

High quality three-dimensional images from conventional MRI, CT, PET, or SPECT scans require that the subject being imaged remain stationary during ...

126

Graphical interface for quantitative monitoring of 3D MRI data  

E-Print Network (OSTI)

The recent development of techniques in magnetic resonance imaging allows for the noninvasive monitoring of cartilage for disease progression, effects of lifestyle change, and results of medical interventions. In particular, ...

Gerber, Meredith L

2005-01-01T23:59:59.000Z

127

Automatic segmentation of the left ventricle cavity and myocardium in MRI data  

Science Conference Proceedings (OSTI)

A novel approach for the automatic segmentation has been developed to extract the epi-cardium and endo-cardium boundaries of the left ventricle (lv) of the heart. The developed segmentation scheme takes multi-slice and multi-phase magnetic resonance ... Keywords: Clustering, Left ventricle, Level-set, MRI, Myocardium, Segmentation

M. Lynch; O. Ghita; P. F. Whelan

2006-04-01T23:59:59.000Z

128

Nuclear Magnetic Resonance Laboratory  

Science Conference Proceedings (OSTI)

Nuclear Magnetic Resonance Laboratory. ... A 600 MHz Nuclear Magnetic Resonance Spectrometer. Analytical Data Compilation Reference Materials. ...

2012-10-01T23:59:59.000Z

129

MRI Ventures | Open Energy Information  

Open Energy Info (EERE)

MRI Ventures MRI Ventures Jump to: navigation, search Logo: MRI Ventures Name MRI Ventures Address 425 Volker Boulevard Place Kansas City, Missouri Zip 64110 Product Handles the commercialization of intellectual property and new technologies that are developed either at MRI or through collaborative efforts Phone number (816) 753-7600 Website http://www.mriresearch.org/Abo Coordinates 39.0386366°, -94.5819018° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.0386366,"lon":-94.5819018,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

130

A REVIEW OF NON-INVASIVE IMAGING METHODS AND APPLICATIONS IN CONTAMINANT HYDROGEOLOGY RESEARCH  

Science Conference Proceedings (OSTI)

Contaminant hydrogeological processes occurring in porous media are typically not amenable to direct observation. As a result, indirect measurements (e.g., contaminant breakthrough at a fixed location) are often used to infer processes occurring at different scales, locations, or times. To overcome this limitation, non-invasive imaging methods are increasingly being used in contaminant hydrogeology research. The most common methods, and the subjects of this review, are optical imaging using UV or visible light, dual-energy gamma-radiation, X-ray microtomography, and magnetic resonance imaging (MRI). Non-invasive imaging techniques have provided valuable insights into a variety of complex systems and processes, including porous media characterization, multiphase fluid distribution, fluid flow, solute transport and mixing, colloidal transport and deposition, and reactions. In this paper we review the theory underlying these methods, applications of these methods to contaminant hydrogeology research, and methods’ advantages and disadvantages. As expected, there is no perfect method or tool for non-invasive imaging. However, optical methods generally present the least expensive and easiest options for imaging fluid distribution, solute and fluid flow, colloid transport, and reactions in artificial two-dimensional (2D) porous media. Gamma radiation methods present the best opportunity for characterization of fluid distributions in 2D at the Darcy scale. X-ray methods present the highest resolution and flexibility for three-dimensional (3D) natural porous media characterization, and 3D characterization of fluid distributions in natural porous media. And MRI presents the best option for 3D characterization of fluid distribution, fluid flow, colloid transport, and reaction in artificial porous media. Obvious deficiencies ripe for method development are the ability to image transient processes such as fluid flow and colloid transport in natural porous media in three-dimensions, the ability to image many reactions of environmental interest in artificial and natural porous media, and the ability to image selected processes over a range of scales in artificial and natural porous media.

Werth, Charles J.; Zhang, Changyong; Brusseau, M. L.; Oostrom, Martinus; Baumann, T.

2010-03-08T23:59:59.000Z

131

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

132

Machine Learning for Medical and Neuroscientific Imaging With hardware approaching fundamental safety and  

E-Print Network (OSTI)

phase, (C) fat and (D) water images. Bottom: attenuation maps created from MR image using (E for MRI Patient motion during long MR scans leads to severe non-local degradations and can render images

133

Fourier Transform Near Infrared Microspectroscopy, Infrared Chemical Imaging, High-Resolution Nuclear Magnetic Resonance and Fluorescence Microspectroscopy Detection of Single Cancer Cells and Single Viral Particles  

E-Print Network (OSTI)

Single Cancer Cells from Human tumors are being detected and imaged by Fourier Transform Infrared (FT-IR), Fourier Transform Near Infrared (FT-NIR)Hyperspectral Imaging and Fluorescence Correlation Microspectroscopy. The first FT-NIR chemical, microscopic images of biological systems approaching one micron resolution are here reported. Chemical images obtained by FT-NIR and FT-IR Microspectroscopy are also presented for oil in soybean seeds and somatic embryos under physiological conditions. FT-NIR spectra of oil and proteins were obtained for volumes as small as two cubic microns. Related, HR-NMR analyses of oil contents in somatic embryos as well as 99% accurate calibrations are also presented here with nanoliter precision. Such high-resolution, 400 MHz H-1 NMR analyses allowed the selection of mutagenized embryos with higher oil content (e.g. >~20%) compared to the average levels in non-mutagenized control embryos. Moreover, developmental changes in single soybean seeds and/or somatic embryos may be monito...

Baianu,I C; Hofmann, N E; Korban, S S; Lozano, P; You, T

2004-01-01T23:59:59.000Z

134

ELECTRON PARAMAGNETIC RESONANCE ...  

Science Conference Proceedings (OSTI)

ELECTRON PARAMAGNETIC RESONANCE SPECTROELECTROCHEMISTRY OF TRANSITION METAL SOLAR FUELS CATALYSTS. ...

135

Excitation and readout Designs for high field spectroscopic imaging  

E-Print Network (OSTI)

In this thesis we state and demonstrate solutions to three engineering problems that arise in magnetic resonance imaging RF excitation with parallel transmission (pTx) and magnetic resonance spectroscopic imaging (MRSI). ...

Lee, Joonsung

2011-01-01T23:59:59.000Z

136

Near Infrared Microspectroscopy, Fluorescence Microspectroscopy, Infrared Chemical Imaging and High Resolution Nuclear Magnetic Resonance Analysis of Soybean Seeds, Somatic Embryos and Single Cells  

E-Print Network (OSTI)

Novel methodologies are currently being developed and established for the chemical analysis of soybean seeds, embryos and single cells by Fourier Transform Infrared (FT-IR), Fourier Transform Near Infrared (FT-NIR) Microspectroscopy, Fluorescence and High-Resolution NMR (HR-NMR). The first FT-NIR chemical images of biological systems approaching one micron resolution are presented here. Chemical images obtained by FT-NIR and FT-IR Microspectroscopy are presented for oil in soybean seeds and somatic embryos under physiological conditions. FT-NIR spectra of oil and proteins were obtained for volumes as small as two cubic microns. Related, HR-NMR analyses of oil contents in somatic embryos are also presented here with nanoliter precision. Such 400 MHz 1H NMR analyses allowed the selection of mutagenized embryos with higher oil content (e.g. ~20%) compared to non-mutagenized control embryos. Moreover, developmental changes in single soybean seeds and/or somatic embryos may be monitored by FT-NIR with a precision ...

Baianu, I C; Hofmann, N E; Korban, S S; Lozano, P; You, T; AOCS 94th Meeting, Kansas

2002-01-01T23:59:59.000Z

137

Suppressed fuzzy-soft learning vector quantization for MRI segmentation  

Science Conference Proceedings (OSTI)

Objective: A self-organizing map (SOM) is a competitive artificial neural network with unsupervised learning. To increase the SOM learning effect, a fuzzy-soft learning vector quantization (FSLVQ) algorithm has been proposed in the literature, using ... Keywords: CPU time, Learning vector quantization, Magnetic resonance image segmentation, Mean squared error, Self-organizing map

Wen-Liang Hung; De-Hua Chen; Miin-Shen Yang

2011-05-01T23:59:59.000Z

138

Deformable B-Solids and Implicit Snakes for Localization and Tracking of SPAMM MRI-Data  

Science Conference Proceedings (OSTI)

To date, MRI-SPAMM data from different image slices have been analyzed independently. In this paper, we propose an approach for 3D tag localization and tracking of SPAMM data by a novel deformable B-solid. The solid is defined in terms of a 3D tensor ...

P. Radeva; A. Amini; J. Huang; E. Martí

1996-06-01T23:59:59.000Z

139

Comprehensive investigation of the non-covalent binding of MRI ...  

Science Conference Proceedings (OSTI)

of MRI contrast agents with human serum albumin. Virginie ... binding between human serum albumin (HSA) and MRI contrast .... The relative error on the T1 ...

140

Temporal diffeomorphic free form deformation (TDFFD) applied to motion and deformation quantification of tagged MRI sequences  

Science Conference Proceedings (OSTI)

This paper presents strain quantification results obtained from the Tagged Magnetic Resonance Imaging (TMRI) sequences acquired for the 1st cardiac Motion Analysis Challenge (cMAC). We applied the Temporal Diffeomorphic Free Form Deformation ...

Mathieu De Craene; Catalina Tobon-Gomez; Constantine Butakoff; Nicolas Duchateau; Gemma Piella; Kawal S. Rhode; Alejandro F. Frangi

2011-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

ARTIFACTS IN MAGNETIC RESONANCE IMAGING FROM ...  

Science Conference Proceedings (OSTI)

... We surmise that the symmetric susceptibility artifact is ... It has two components, the first handling material ... the positive z-axis, the z-component of the ...

142

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Wednesday, 28 March 2012 00:00 Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

143

Using X-ray mammograms to assist in microwave breast image interpretation  

Science Conference Proceedings (OSTI)

Current clinical breast imaging modalities include ultrasound, magnetic resonance (MR) imaging, and the ubiquitous X-ray mammography. Microwave imaging, which takes advantage of differing electromagnetic properties to obtain image contrast, shows potential ...

Charlotte Curtis; Richard Frayne; Elise Fear

2012-01-01T23:59:59.000Z

144

Nanomechanical resonance detector  

SciTech Connect

An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

Grossman, Jeffrey C; Zettl, Alexander K

2013-10-29T23:59:59.000Z

145

Available Technologies: Remote NMR/MRI Detection  

Low field encoding : High field detection = better sensitivity. APPLICATIONS: Enhanced sensitivity expands the uses of nuclear magnetic resonance ...

146

On the relevance of automatically selected single-voxel MRS and multimodal MRI and MRSI features for brain tumour differentiation  

Science Conference Proceedings (OSTI)

In order to evaluate the relevance of magnetic resonance (MR) features selected by automatic feature selection techniques to build classifiers for differential diagnosis and tissue segmentation two data sets containing MR spectroscopy data from patients ... Keywords: ANOVA, ARD, Ala, Automatic feature selection, Brain tumour, CSF, Cho, Cr, Differential diagnosis, Gd, Glc, Glx, Gly, HLSVD, LDA, LS-SVM, Lac, Lip, MR, MRI, MRS, MRSI, NAA, PD, PRESS, QDA, STEAM, SVM, TE, TM, TR, Tau, mI

Geert J. Postma; Jan Luts; Albert J. Idema; Margarida Julií-Sapé; Ángel Moreno-Torres; Witek Gajewicz; Johan A. K. Suykens; Arend Heerschap; Sabine Van Huffel; Lutgarde M. C. Buydens

2011-02-01T23:59:59.000Z

147

MAPPING HUMAN BRAIN FUNCTION WITH MRI AT 7 TESLA Xiaoping HU, Essa YACOUB, Josef PFEUFFER, Amir SCHUMEL,  

E-Print Network (OSTI)

MAPPING HUMAN BRAIN FUNCTION WITH MRI AT 7 TESLA Xiaoping HU, Essa YACOUB, Josef PFEUFFER, Amir of the BOLD response to neural activity increase with the field strength. With the establishment of a 7 Tesla at a magnetic field strength that significantly exceeds 4 Tesla. Functional mapping using echo-planar imaging

148

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. 72 DPI Image 150 DPI Image No 300 DPI Version. Title: Frequency Comb, Ultrafast Laser. ...

149

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. 72 DPI Image 150 DPI Image No 300 DPI Version. Title: Iron-Based Superconductors. Description ...

150

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. 72 DPI Image 150 DPI Image No 300 DPI Version. Title: Space Weather Forecasts. Description ...

151

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. 72 DPI Image 150 DPI Image No 300 DPI Version. Title: Organic Solar Power. Description ...

152

A Prospective Randomized Trial to Study the Impact of Pretreatment FDG-PET for Cervical Cancer Patients With MRI-Detected Positive Pelvic but Negative Para-Aortic Lymphadenopathy  

Science Conference Proceedings (OSTI)

Purpose: This prospective randomized study was undertaken to determine the possible impact of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) on extrapelvic metastasis detection, radiation field design, and survival outcome for cervical cancer patients with enlarged pelvic nodes on MRI image. Methods and Materials: Inclusion criteria were patients with newly diagnosed Stage I-IVA cervical cancer and with positive pelvic but negative para-aortic lymph nodes (PALN) as detected by magnetic resonance image and good performance status for concurrent chemoradiotherapy. Eligible patients were randomized to receive either pretreatment FDG-PET (study group) or not (control group). Whole pelvis was the standard irradiation field for the control group and those with no extrapelvic findings on PET. The radiation fields for the rest of the study group were extended to include the PALN region or were modified according to the extrapelvic PET finding. Results: From January 2002 to April 2006, 129 patients were included, and 66 of them were randomized to receive FDG-PET. PET detected seven extrapelvic metastases (11%, 6 PALN and 1 omental node), and four of them remained disease-free after treatment modification. For patients who underwent PET compared with those who did not, there were no differences in the 4-year rates of overall survival (79% vs. 85%, p = 0.65), disease-free survival (75% vs. 77%, p = 0.64), and distant metastasis-free survival (82% vs. 78%, p = 0.83). Conclusions: Pretreatment FDG-PET in conjunction with magnetic resonance imaging can improve the detection of extrapelvic metastasis, mainly PALN, and help select patients for extended-field radiotherapy. However, the addition of FDG-PET may not translate into survival benefit, even though PALN relapses are reduced.

Tsai, C.-S. [Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan (China); Department of Medical Imaging and Radiological Science, Chang Gung University, School of Medicine, Taoyuan, Taiwan (China); Lai, C.-H.; Chang, T.-C. [Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan (China); Yen, T.-C. [Department of Nuclear Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan (China); Ng, K.-K. [Department of Diagnostic Radiology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan (China); Hsueh Swei [Department of Pathology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan (China); Lee, Steve P. [Department of Radiation Oncology, University of California, Los Angeles, CA (United States); Hong, J.-H., E-mail: jihong@adm.cgmh.org.t [Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan (China); Department of Medical Imaging and Radiological Science, Chang Gung University, School of Medicine, Taoyuan, Taiwan (China)

2010-02-01T23:59:59.000Z

153

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Nanotechnology; Biotechnology/Health; Nanocrystals; Hwang. ...

154

Monofilament MgB? wires for MRI magnets  

E-Print Network (OSTI)

MRI magnets are useful medical devices in early detection and efficient treatment of disease or injury. Because of the significant better performance, MRI magnets are made of superconductors rather than made of copper. ...

Ling, Jiayin

2012-01-01T23:59:59.000Z

155

Instrument guide for MRI-guided percutaneous interventions  

E-Print Network (OSTI)

As MRI guided interventions are becoming more widely practiced, the goal of this thesis was to design an instrument guidance device for MRI-guided percutaneous interventions in closed bore systems, namely cryoablation ...

Chen, Xuefeng, S.B. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

156

Motor representations and practice affect brain systems underlying imagery: an fMRI study of internal imagery in novices and active high jumpers. Open Neuroimaging  

E-Print Network (OSTI)

Abstract: This study used functional magnetic resonance imaging (fMRI) to investigate differences in brain activity between one group of active high jumpers and one group of high jumping novices (controls) when performing motor imagery of a high jump. It was also investigated how internal imagery training affects neural activity. The results showed that active high jumpers primarily activated motor areas, e.g. pre-motor cortex and cerebellum. Novices activated visual areas, e.g. superior occipital cortex. Imagery training resulted in a reduction of activity in parietal cortex. These results indicate that in order to use an internal perspective during motor imagery of a complex skill, one must have well established motor representations of the skill which then translates into a motor/internal pattern of brain activity. If not, an external perspective will be used and the corresponding brain activation will be a visual/external pattern. Moreover, the findings imply that imagery training reduces the activity in parietal cortex suggesting that imagery is performed more automatic and results in a more efficient motor representation more easily accessed during motor performance.

C. -j. Olsson; Bert Jonsson; Anne Larsson; Lars Nyberg

2008-01-01T23:59:59.000Z

157

Concurrent segmentation of the prostate on MRI and CT via linked statistical shape models for radiotherapy planning  

Science Conference Proceedings (OSTI)

Purpose: Prostate gland segmentation is a critical step in prostate radiotherapy planning, where dose plans are typically formulated on CT. Pretreatment MRI is now beginning to be acquired at several medical centers. Delineation of the prostate on MRI is acknowledged as being significantly simpler to perform, compared to delineation on CT. In this work, the authors present a novel framework for building a linked statistical shape model (LSSM), a statistical shape model (SSM) that links the shape variation of a structure of interest (SOI) across multiple imaging modalities. This framework is particularly relevant in scenarios where accurate boundary delineations of the SOI on one of the modalities may not be readily available, or difficult to obtain, for training a SSM. In this work the authors apply the LSSM in the context of multimodal prostate segmentation for radiotherapy planning, where the prostate is concurrently segmented on MRI and CT. Methods: The framework comprises a number of logically connected steps. The first step utilizes multimodal registration of MRI and CT to map 2D boundary delineations of the prostate from MRI onto corresponding CT images, for a set of training studies. Hence, the scheme obviates the need for expert delineations of the gland on CT for explicitly constructing a SSM for prostate segmentation on CT. The delineations of the prostate gland on MRI and CT allows for 3D reconstruction of the prostate shape which facilitates the building of the LSSM. In order to perform concurrent prostate MRI and CT segmentation using the LSSM, the authors employ a region-based level set approach where the authors deform the evolving prostate boundary to simultaneously fit to MRI and CT images in which voxels are classified to be either part of the prostate or outside the prostate. The classification is facilitated by using a combination of MRI-CT probabilistic spatial atlases and a random forest classifier, driven by gradient and Haar features. Results: The authors acquire a total of 20 MRI-CT patient studies and use the leave-one-out strategy to train and evaluate four different LSSMs. First, a fusion-based LSSM (fLSSM) is built using expert ground truth delineations of the prostate on MRI alone, where the ground truth for the gland on CT is obtained via coregistration of the corresponding MRI and CT slices. The authors compare the fLSSM against another LSSM (xLSSM), where expert delineations of the gland on both MRI and CT are employed in the model building; xLSSM representing the idealized LSSM. The authors also compare the fLSSM against an exclusive CT-based SSM (ctSSM), built from expert delineations of the gland on CT alone. In addition, two LSSMs trained using trainee delineations (tLSSM) on CT are compared with the fLSSM. The results indicate that the xLSSM, tLSSMs, and the fLSSM perform equivalently, all of them out-performing the ctSSM. Conclusions: The fLSSM provides an accurate alternative to SSMs that require careful expert delineations of the SOI that may be difficult or laborious to obtain. Additionally, the fLSSM has the added benefit of providing concurrent segmentations of the SOI on multiple imaging modalities.

Chowdhury, Najeeb; Toth, Robert; Chappelow, Jonathan; Kim, Sung; Motwani, Sabin; Punekar, Salman; Lin Haibo; Both, Stefan; Vapiwala, Neha; Hahn, Stephen; Madabhushi, Anant

2012-04-15T23:59:59.000Z

158

Meet Phannie, NIST's Standard 'Phantom' for Calibrating MRI ...  

Science Conference Proceedings (OSTI)

Meet Phannie, NIST's Standard 'Phantom' for Calibrating MRI Machines. ... The National Institute of Standards and Technology (NIST) has unveiled ...

2013-07-11T23:59:59.000Z

159

Video Toroid Cavity Imager  

DOE Patents (OSTI)

A video toroid cavity imager for in situ measurement of electrochemical properties of an electrolytic material sample includes a cylindrical toroid cavity resonator containing the sample and employs NMR and video imaging for providing high-resolution spectral and visual information of molecular characteristics of the sample on a real-time basis. A large magnetic field is applied to the sample under controlled temperature and pressure conditions to simultaneously provide NMR spectroscopy and video imaging capabilities for investigating electrochemical transformations of materials or the evolution of long-range molecular aggregation during cooling of hydrocarbon melts. The video toroid cavity imager includes a miniature commercial video camera with an adjustable lens, a modified compression coin cell imager with a fiat circular principal detector element, and a sample mounted on a transparent circular glass disk, and provides NMR information as well as a video image of a sample, such as a polymer film, with micrometer resolution.

Gerald, Rex E. II; Sanchez, Jairo; Rathke, Jerome W.

2004-08-10T23:59:59.000Z

160

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Regarding Confinement Resonances Regarding Confinement Resonances Print Wednesday, 27 July 2011 00:00 When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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161

Resonant snubber inverter  

DOE Patents (OSTI)

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 14 figs.

Lai, J.S.; Young, R.W. Sr.; Chen, D.; Scudiere, M.B.; Ott, G.W. Jr.; White, C.P.; McKeever, J.W.

1997-06-24T23:59:59.000Z

162

Resonant snubber inverter  

DOE Patents (OSTI)

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Lai, Jih-Sheng (Knoxville, TN); Young, Sr., Robert W. (Oak Ridge, TN); Chen, Daoshen (Knoxville, TN); Scudiere, Matthew B. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN); White, Clifford P. (Knoxville, TN); McKeever, John W. (Oak Ridge, TN)

1997-01-01T23:59:59.000Z

163

Near Infrared Surface Plasmon Resonance Phase Imaging and Nanoparticle-Enhanced Surface Plasmon Resonance Phase Imaging  

E-Print Network (OSTI)

utilized a near-infrared 860 nm light emitting diode (LED) light source and a wedge depolarizer to create

164

Multiphase imaging of gas flow in a nanoporous material using remote detection NMR  

E-Print Network (OSTI)

D.P. Weitekamp, “Zero field NMR and NQR”, J. Chem. Phys.Amplification of xenon NMR and MRI by remote detection”,of silica aerogels by 129 Xe NMR spectroscopy and imaging”,

Harel, Elad; Granwehr, Josef; Seeley, Juliette A.; Pines, Alex

2005-01-01T23:59:59.000Z

165

ELECTRON PARAMAGNETIC RESONANCE IN BIOLOGY  

E-Print Network (OSTI)

published in Perspectives in Biology and Medicine. ) 51. D.PARAMAGNETIC RESONANCE IN BIOLOGY G. M. Androes and Melvinparamagnetic resonance in biology is presented, including a

Androes, G.M.; Calvin, Melvin.

2008-01-01T23:59:59.000Z

166

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Quantum Physics; Quantum Communications; Ultrafast Photon Detector; Nam. ...

167

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Energy; Fossil Fuels;Distillation Curves for Complex Fuel Mixtures. ...

168

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Scanning Electron Microscope with Spin Polarization Analysis. ...

169

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Metrology, Basic Units; Mass; Electronic Kilogram. Description ...

170

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... nist.gov. 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Public safety & Smart Grid. Description: Electrical engineer ...

171

Spin resonance strength calculations  

SciTech Connect

In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.

Courant,E.D.

2008-10-06T23:59:59.000Z

172

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. 72 DPI Image No 150 DPI Version 300 DPI Image. Title: Ultrafast Laser Speeds Up Quest for Atomic Control. ...

173

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. 72 DPI Image 150 DPI Image No 300 DPI Version. Title: House; Trees. Description: *BFRL. Subjects (names): ...

174

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: New Imaging Tool is Boon to Fuel Cell Research. Description: NIST ...

175

The feasibility of Quadrupole Dip Imaging with PMRI: focus on multiple sclerosis  

E-Print Network (OSTI)

Magnetic Resonance (MR) techniques provide valuable information for the diagnosis, monitoring, treatment, and study of many diseases. However, limitations on the sensitivity and specificity warrant the development of new imaging techniques. Quadrupole Dip Imaging (QDI) is a novel MR technique based on the magnitude of the quadrupole dip in the T? dispersion profile of substances containing rotationally immobilized proteins. The implementation of QDI requires field-cycled (FC) relaxometry. Prepolarized NM (PNW could potentially provide a low-cost way to conduct FC experiments and thus implement QDI. I have conducted a literature review and analysis to predict the value of using QDI to study Multiple Sclerosis (MS), to determine the feasibility of implementing QDI with PMRI, and to identify obstacles to successful penetration of the technology to the clinical environment. QDI could potentially be used to non-invasively create protein density maps in vivo, which could provide clinically valuable information on the histopathological substrate of MS that is not available through present imaging techniques. It appears that this information will be most valuable for studies of the development and nature of the diseases instead of for diagnosis and disease monitoring. Factors that will affect the development and dissemination of QDI with PNM include the development of PMRI T?-measuring pulse sequences that are robust to inhomogeneity and field ramping, the inherently small signal and dynamic range of QDI, and MR hardware acquisition trends towards high-field devices. QDI with PMRI will probably maintain or exceed conventional MRI safety, patient tolerance, and cost. I have also conducted experiments that demonstrate that PNM can, in fact, be used to create dispersion profiles. Using the home-made PNM scanner at the Magnetic Resonance Systems Laboratory at Texas A&M I have verified the linearity of SNR with increasing prepolarizing field strength and demonstrated qualitatively the feasibility of T? measurement at different field strengths for CuSO? (aq) and Bovine Serum Albumin/gluteraldehyde phantoms.

Jeter, Edward Hilton

2001-01-01T23:59:59.000Z

176

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Print Regarding Confinement Resonances Print When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

177

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Print Regarding Confinement Resonances Print When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

178

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Print Regarding Confinement Resonances Print When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

179

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but...

180

Cylindrical laser resonator  

DOE Patents (OSTI)

The properties of an improved class of lasers is presented. In one configuration of these lasers the radiation propagates radially within the amplifying medium, resulting in high fields and symmetric illumination at the resonator axis. Thus there is a strong focusing of energy at the axis of the resonator. In a second configuration the radiation propagates back and forth in a tubular region of space.

Casperson, Lee W. (Los Angeles, CA)

1976-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Nuclear Resonance Fluorescence for Nuclear Materials Assay  

E-Print Network (OSTI)

Potential of Nuclear Resonance Fluorescence . . . . . . . .2.9.1 Nuclear ThomsonSections . . . . . . . . . . . . . . . Nuclear Resonance

Quiter, Brian Joseph

2010-01-01T23:59:59.000Z

182

Resonant nonlinear ultrasound spectroscopy  

DOE Patents (OSTI)

Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift .vertline..DELTA..function./.function..sub.0.vertline., is determined as a function of applied strain amplitude for an acceptable component, where .function..sub.0 is the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak of a selected mode to determine a reference relationship. Then, the relative resonance frequency shift .vertline..DELTA..function./.function..sub.0 is determined as a function of applied strain for a component under test, where fo .function..sub.0 the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak to determine a quality test relationship. The reference relationship is compared with the quality test relationship to determine the presence of defects in the component under test.

Johnson, Paul A. (Santa Fe, NM); TenCate, James A. (Los Alamos, NM); Guyer, Robert A. (Amherst, MA); Van Den Abeele, Koen E. A. (Sint-Niklaas, BE)

2001-01-01T23:59:59.000Z

183

Selective Averaging of Rapidly Presented Individual Trials Using fMRI  

E-Print Network (OSTI)

a train of identical stimuli [Squires et al., 1977]. Similarly, a variety of cognitive experi- ments. General magnetic resonance (MR) procedures Imaging was performed on a 1.5 T General Electric scanner response model. Each trial consisted of a 1-sec full- field 8-Hz counterphased flickering visual checker

Rotstein, Horacio G.

184

Agentification of Markov model-based segmentation: Application to magnetic resonance brain scans  

Science Conference Proceedings (OSTI)

Objective: Markov random field (MRF) models have been traditionally applied to the task of robust-to-noise image segmentation. Most approaches estimate MRF parameters on the whole image via a global expectation-maximization (EM) procedure. The resulting ... Keywords: Distributed expectation maximization, Magnetic resonance brain scan segmentation, Markov random field, Medical imaging, Multiagents system

Benoit Scherrer; Michel Dojat; Florence Forbes; Catherine Garbay

2009-05-01T23:59:59.000Z

185

9.71 Functional MRI of High-Level Vision, Fall 2004  

E-Print Network (OSTI)

Covers the basics of fMRI, the strengths and limitations of fMRI compared to other techniques, and the design and analysis of fMRI experiments, focusing primarily on experiments on high-level vision. Upon completion, ...

Kanwisher, Nancy

186

Quartz resonator processing system  

DOE Patents (OSTI)

Disclosed is a single chamber ultra-high vacuum processing system for the oduction of hermetically sealed quartz resonators wherein electrode metallization and sealing are carried out along with cleaning and bake-out without any air exposure between the processing steps. The system includes a common vacuum chamber in which is located a rotatable wheel-like member which is adapted to move a plurality of individual component sets of a flat pack resonator unit past discretely located processing stations in said chamber whereupon electrode deposition takes place followed by the placement of ceramic covers over a frame containing a resonator element and then to a sealing stage where a pair of hydraulic rams including heating elements effect a metallized bonding of the covers to the frame.

Peters, Roswell D. M. (Rustburg, VA)

1983-01-01T23:59:59.000Z

187

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Homeland Security; Chem., Bio, and Other Threats; Standards for Radiation Detection. ...

188

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Image Gallery : Image Details. No 72 DPI Version No 150 DPI Version 300 DPI Image. Title: Gold Nano Anchors Put Nanowires in Their Place. ...

189

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image © 150 DPI Image © 300 DPI Image ©. Title: Iron-based and Copper-Oxide High-Temperature Superconductors. ...

190

A Bayesian nonrigid registration method to enhance intraoperative target definition in image-guided prostate procedures through uncertainty characterization  

Science Conference Proceedings (OSTI)

Purpose: This study introduces a probabilistic nonrigid registration method for use in image-guided prostate brachytherapy. Intraoperative imaging for prostate procedures, usually transrectal ultrasound (TRUS), is typically inferior to diagnostic-quality imaging of the pelvis such as endorectal magnetic resonance imaging (MRI). MR images contain superior detail of the prostate boundaries and provide substructure features not otherwise visible. Previous efforts to register diagnostic prostate images with the intraoperative coordinate system have been deterministic and did not offer a measure of the registration uncertainty. The authors developed a Bayesian registration method to estimate the posterior distribution on deformations and provide a case-specific measure of the associated registration uncertainty. Methods: The authors adapted a biomechanical-based probabilistic nonrigid method to register diagnostic to intraoperative images by aligning a physician's segmentations of the prostate in the two images. The posterior distribution was characterized with a Markov Chain Monte Carlo method; the maximum a posteriori deformation and the associated uncertainty were estimated from the collection of deformation samples drawn from the posterior distribution. The authors validated the registration method using a dataset created from ten patients with MRI-guided prostate biopsies who had both diagnostic and intraprocedural 3 Tesla MRI scans. The accuracy and precision of the estimated posterior distribution on deformations were evaluated from two predictive distance distributions: between the deformed central zone-peripheral zone (CZ-PZ) interface and the physician-labeled interface, and based on physician-defined landmarks. Geometric margins on the registration of the prostate's peripheral zone were determined from the posterior predictive distance to the CZ-PZ interface separately for the base, mid-gland, and apical regions of the prostate. Results: The authors observed variation in the shape and volume of the segmented prostate in diagnostic and intraprocedural images. The probabilistic method allowed us to convey registration results in terms of posterior distributions, with the dispersion providing a patient-specific estimate of the registration uncertainty. The median of the predictive distance distribution between the deformed prostate boundary and the segmented boundary was Less-Than-Or-Slanted-Equal-To 3 mm (95th percentiles within {+-}4 mm) for all ten patients. The accuracy and precision of the internal deformation was evaluated by comparing the posterior predictive distance distribution for the CZ-PZ interface for each patient, with the median distance ranging from -0.6 to 2.4 mm. Posterior predictive distances between naturally occurring landmarks showed registration errors of Less-Than-Or-Slanted-Equal-To 5 mm in any direction. The uncertainty was not a global measure, but instead was local and varied throughout the registration region. Registration uncertainties were largest in the apical region of the prostate. Conclusions: Using a Bayesian nonrigid registration method, the authors determined the posterior distribution on deformations between diagnostic and intraprocedural MR images and quantified the uncertainty in the registration results. The feasibility of this approach was tested and results were positive. The probabilistic framework allows us to evaluate both patient-specific and location-specific estimates of the uncertainty in the registration result. Although the framework was tested on MR-guided procedures, the preliminary results suggest that it may be applied to TRUS-guided procedures as well, where the addition of diagnostic MR information may have a larger impact on target definition and clinical guidance.

Pursley, Jennifer; Risholm, Petter; Fedorov, Andriy; Tuncali, Kemal; Fennessy, Fiona M.; Wells, William M. III; Tempany, Clare M.; Cormack, Robert A. [Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115 (United States); Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States); Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115 (United States)

2012-11-15T23:59:59.000Z

191

RESONANT CAVITY EXCITATION SYSTEM  

DOE Patents (OSTI)

A cavity excitation circuit is described for rapidly building up and maintaining high-level oscillations in a resonant cavity. The circuit overcomes oscillation buildup slowing effects such as ion locking in the cavity by providing for the selective application of an amplified accelerating drive signal to the main cavity exciting oscillator during oscillation buildup and a direct drive signal to the oscillator thereafter.

Baker, W.R.

1959-08-01T23:59:59.000Z

192

RESONATOR PARTICLE SEPARATOR  

DOE Patents (OSTI)

A wave-guide resonator structure is designed for use in separating particles of equal momentum but differing in mass, having energies exceeding one billion eiectron volts. The particles referred to are those of sub-atomic size and are generally produced as a result of the bombardment of a target by a beam such as protons produced in a high energy accelerator. In the resonator a travelling electric wave is produced which travels at the same rate of speed as the unwanted particle which is thus deflected continuously over the length of the resonator. The wanted particle is slightly out of phase with the travelling wave so that over the whole length of the resonator it has a net deflection of substantially zero. The travelling wave is established in a wave guide of rectangular cross section in which stubs are provided to store magnetic wave energy leaving the electric wave energy in the main structure to obtain the desired travelling wave and deflection. The stubs are of such shape and spacing to establish a critical mathemitical relationship. (AEC)

Blewett, J.P.; Kiesling, J.D.

1963-06-11T23:59:59.000Z

193

Nucleon-nucleon resonances  

SciTech Connect

The experimental techniques related to NN resonance measurements are described. The technique used is the good geometry transmission experiment. The basic idea is to measure the difference in the attenuation factor for the corresponding difference between the total cross sections of N + N interactions for forward and reverse momentum as a function of the solenoid current. 26 references. (JFP)

Auer, I.P.

1979-01-01T23:59:59.000Z

194

(New imaging systems in nuclear medicine)  

SciTech Connect

Further progress has been made on improving the uniformity and stability of PCR-I, the single ring analog coded tomograph. This camera has been employed in a wide range of animal studies described below. Data from PCR-I have been used in various image processing procedures. These include motion pictures of dog heart, comparison of PET and MRI image in dog heart and rat brain and quantitation of tumor metabolism in the nude mouse using blood data from heart images. A SUN workstation with TAAC board has been used to produce gated three-dimensional images of the dog heart. The ANALYZE program from the Mayo Clinic has also been mounted on a SUN workstation for comparison of images and image processing. 15 refs., 6 figs.

1990-01-01T23:59:59.000Z

195

Polarization transfer NMR imaging  

DOE Patents (OSTI)

A nuclear magnetic resonance (NMR) image is obtained with spatial information modulated by chemical information. The modulation is obtained through polarization transfer from a first element representing the desired chemical, or functional, information, which is covalently bonded and spin-spin coupled with a second element effective to provide the imaging data. First and second rf pulses are provided at first and second frequencies for exciting the imaging and functional elements, with imaging gradients applied therebetween to spatially separate the nuclei response for imaging. The second rf pulse is applied at a time after the first pulse which is the inverse of the spin coupling constant to select the transfer element nuclei which are spin coupled to the functional element nuclei for imaging. In a particular application, compounds such as glucose, lactate, or lactose, can be labeled with .sup.13 C and metabolic processes involving the compounds can be imaged with the sensitivity of .sup.1 H and the selectivity of .sup.13 C.

Sillerud, Laurel O. (Los Alamos, NM); van Hulsteyn, David B. (Santa Fe, NM)

1990-01-01T23:59:59.000Z

196

NIST Electron Paramagnetic Resonance Facility  

Science Conference Proceedings (OSTI)

... leading a national and international effort in electron paramagnetic resonance ... centers (molecules or atoms with unpaired electrons) are produced ...

197

Repetitive resonant railgun power supply  

DOE Patents (OSTI)

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

198

Magnetic Resonance Facility (Fact Sheet)  

DOE Green Energy (OSTI)

This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

Not Available

2012-03-01T23:59:59.000Z

199

Repetitive resonant railgun power supply  

DOE Patents (OSTI)

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Honig, E.M.; Nunnally, W.C.

1985-06-19T23:59:59.000Z

200

Tandem resonator reflectance modulator  

DOE Patents (OSTI)

A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors. 8 figs.

Fritz, I.J.; Wendt, J.R.

1994-09-06T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Tandem resonator reflectance modulator  

DOE Patents (OSTI)

A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors.

Fritz, Ian J. (Albuquerque, NM); Wendt, Joel R. (Albuquerque, NM)

1994-01-01T23:59:59.000Z

202

RESONATOR PARTICLE SEPARATOR  

DOE Patents (OSTI)

A wave guide resonator structure is described for use in separating particles of equal momentum but differing in mass and having energies exceeding one billion electron volts. The particles are those of sub-atomic size and are generally produced as a result of the bombardment of a target by a beam such as protons produced in a high-energy accelerator. In this wave guide construction, the particles undergo preferential deflection as a result of the presence of an electric field. The boundary conditions established in the resonator are such as to eliminate an interfering magnetic component, and to otherwise phase the electric field to obtain a traveling wave such as one which moves at the same speed as the unwanted particle. The latter undergoes continuous deflection over the whole length of the device and is, therefore, eliminated while the wanted particle is deflected in opposite directions over the length of the resonator and is thus able to enter an exit aperture. (AEC)

Blewett, J.P.

1962-01-01T23:59:59.000Z

203

DOI 10.1007/s12245-010-0183-y CLINICAL IMAGES Early recognition and management of Lyme carditis  

E-Print Network (OSTI)

A 20-year-old man presented to the emergency department with 2 weeks of migratory arthralgias and several macular blanching rashes. A photograph taken by the patient upon initial eruption of the rash was presented during evaluation (Fig. 1). The lesions were suspicious for erythema migrans (Fig. 2). Upon review of systems, the patient earlier reported a brief episode of palpitations. Electrocardiogram revealed first-degree atrioventricular (AV) block (PR interval 320 ms). He was admitted for telemetry monitoring and intravenous ceftriaxone. He developed asymptomatic Wenckebach which progressed to a high-grade second-degree AV block (Fig. 3). Echocardiography showed global ventricular dysfunction (ejection fraction of 35%). Cardiac magnetic resonance imaging (MRI) revealed inflammation around the AV node (Fig. 4). Lyme carditis was confirmed after Western blot revealed Borrelia burgdorferi antibodies. The patient had resolution of symptoms 4 weeks after intravenous ceftriaxone treatment. Follow-up echocardiography, 5 months later, revealed normal left ventricular function (ejection fraction of 55%). Patients with PR intervals greater than 300 ms are at risk for developing high-grade heart block [1, 2]. They can progress from first-degree heart block into complete Fig. 1 Mobile phone image of erythema migrans at time of initial eruption

Pholaphat Charles Inboriboon; P. C. Inboriboon

2010-01-01T23:59:59.000Z

204

Fast and robust analysis of dynamic contrast enhanced MRI datasets  

Science Conference Proceedings (OSTI)

A fully automated method for quantitative analysis of dynamic contrast-enhanced MRI data acquired with low and high field scanners, using spin echo and gradient echo sequences, depicting various joints is presented. The method incorporates efficient ...

Olga Kubassova; Mikael Boesen; Roger D. Boyle; Marco A. Cimmino; Karl E. Jensen; Henning Bliddal; Alexandra Radjenovic

2007-10-01T23:59:59.000Z

205

MgB[subscript 2] Coils for MRI Applications  

E-Print Network (OSTI)

In this paper, we report our progress in the development of a low cost, liquid-helium-free MgB2 superconducting MRI magnet. Several technical issues related to the construction of such a magnet to operate in persistent ...

Yao, Weijun

206

Parameter selection for suppressed fuzzy c-means with an application to MRI segmentation  

Science Conference Proceedings (OSTI)

This paper presents an algorithm, called the modified suppressed fuzzy c-means (MS-FCM), that simultaneously performs clustering and parameter selection for the suppressed fuzzy c-means (S-FCM) algorithm proposed by [Fan, J.L., Zhen, W.Z., Xie, W.X., ... Keywords: Fuzzy c-means, Fuzzy clustering, Magnetic resonance image segmentation, Parameter selection, Suppressed fuzzy c-means

Wen-Liang Hung; Miin-Shen Yang; De-Hua Chen

2006-04-01T23:59:59.000Z

207

Resonance test system  

DOE Patents (OSTI)

An apparatus (10) for applying at least one load to a specimen (12) according to one embodiment of the invention may comprise a mass (18). An actuator (20) mounted to the specimen (12) and operatively associated with the mass (18) moves the mass (18) along a linear displacement path (22) that is perpendicular to a longitudinal axis of the specimen (12). A control system (26) operatively associated with the actuator (20) operates the actuator (20) to reciprocate the mass (18) along the linear displacement path (22) at a reciprocating frequency, the reciprocating frequency being about equal to a resonance frequency of the specimen (12) in a test configuration.

Musial, Walter (Boulder, CO); White, Darris (Superior, CO)

2011-05-31T23:59:59.000Z

208

Quantum search with resonances  

E-Print Network (OSTI)

We present a continuous time quantum search algorithm analogous to Grover's. In particular, the optimal search time for this algorithm is proportional to $\\sqrt{N}$, where $N$ is the database size. This search algorithm can be implemented using any Hamiltonian with a discrete energy spectrum through excitation of resonances between an initial and the searched state. This algorithm is robust and, as in the case of Grover's, it allows for an error $O(1/\\sqrt{N})$ in the determination of the searched state. A discrete time version of this continuous time search algorithm is built, and the connection between the search algorithms with discrete and continuous times is established.

A. Romanelli; A. Auyuanet; R. Donangelo

2005-02-24T23:59:59.000Z

209

Ion cyclotron resonance cell  

DOE Patents (OSTI)

An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

Weller, R.R.

1995-02-14T23:59:59.000Z

210

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... 72 DPI Image 150 DPI Image No 300 DPI Version. Title: NIST Finds that Ethanol-Loving Bacteria Accelerate Cracking of Pipeline Steels. ...

211

Physics Out Loud - Particle Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle Accelerator Previous Video (Particle Accelerator) Physics Out Loud Main Index Next Video (Photomultiplier Tube) Photomultiplier Tube Particle Resonance How is a particle...

212

Detection sensitivity of x-ray CT imaging for NDE of green-state ceramics  

DOE Green Energy (OSTI)

Improved ceramic-processing methods that use pressure slip-casting and injection molding are being developed at Norton Advanced Ceramics, with a goal of producing reliable structural ceramics for advanced heat engines. Nondestructive evaluation (NDE) of ceramic parts at different stages of processing can provide useful diagnostic information to help improve processing techniques. For example, an evaluation of density gradients in as-cast green-body samples can be used to judge mold performance and make changes in mold design. Also, the ability to detect minute flaws (20 to 50 {mu}m), such as agglomerates, inclusions, and voids, in green-body, presintered, and densified parts is important in ensuring structural reliability of the final parts, because these flaws, above certain critical sizes, can lead to catastrophic failure. Three-dimensional microfocus X-ray computed tomography (CT) and nuclear magnetic resonance imaging (MRI) systems have been developed at Argonne National Laboratory (ANL) for application to quantitative NDE evaluation of ceramics. This paper evaluates the detection sensitivity of the ANL X-ray CT system when used to determine density gradients, inclusions, and voids in green-state Si{sub 3}N{sub 4} ceramics. A theoretical account of key system- and sample-related parameters affecting X-ray CT detection sensitivity is given, and results of experimental evaluation are presented. Density calibration phantoms and net-shape-formed tensile rods with seeded defects were used in the experimental evaluation of detection limits. 6 refs., 6 figs., 1 tab.

Gopalsami, N.; Rizo, P.; Ellingson, W.A. (Argonne National Lab., IL (United States)); Tracey, D.M. (Norton Co., Northboro, MA (United States). Advanced Ceramics Div.)

1991-01-01T23:59:59.000Z

213

Object extraction from T2 weighted brain MR image using histogram based gradient calculation  

Science Conference Proceedings (OSTI)

Several segmentation methods have been reported with their own pros and cons. Here we proposed a method for object extraction from T2 weighted (T2) brain magnetic resonance (MR) images. The proposed method is purely based on histogram processing for ... Keywords: Cerebrospinal fluid, Gray matter, Magnetic resonance imaging, Object extraction, White matter

Ghulam Gilanie, Muhammad Attique, Hafeez-Ullah, Shahid Naweed, Ejaz Ahmed, Masroor Ikram

2013-09-01T23:59:59.000Z

214

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Title: Scanning tunneling microscope; Semiconductor; Spintronics. Description: [Left] A high resolution STM image of a manganese ...

215

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Title: Nanotechnology--Nanomanufacturing; Optical Nano Vision. Description: A new optical imaging technology under ...

216

SPIE Medical Imaging Medical Imaging  

E-Print Network (OSTI)

1 SPIE Medical Imaging 2006 1 Medical Imaging Fundamentals Kenneth H. Wong, Ph.D. Division of Computer Assisted Interventions and Medical Robotics (CAIMR) Imaging Science and Information Systems (ISIS) Center Department of Radiology Georgetown University SPIE Medical Imaging 2006 2 Main Themes · Describe

Miga, Michael I.

217

Baryon Spectroscopy and Resonances  

SciTech Connect

A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of intense effort, notably the ordering of the Roper resonance in the low-lying Nucleon spectrum.

Robert Edwards

2011-12-01T23:59:59.000Z

218

Shape resonances in molecular fields  

SciTech Connect

A shape resonance is a quasibound state in which a particle is temporarily trapped by a potential barrier (i.e., the shape of the potential), through which it may eventually tunnel and escape. This simple mechanism plays a prominent role in a variety of excitation processes in molecules, ranging from vibrational excitation by slow electrons to ionization of deep core levels by X-rays. Moreover, their localized nature makes shape resonances a unifying link between otherwise dissimilar circumstances. One example is the close connection between shape resonances in electron-molecule scattering and in molecular photoionization. Another is the frequent persistence of free-molecule shape resonant behavior upon adsorption on a surface or condensation into a molecular solid. The main focus of this article is a discussion of the basic properties of shape resonances in molecular fields, illustrated by the more transparent examples studied over the last ten years. Other aspects to be discussed are vibrational effects of shape resonances, connections between shape resonances in different physical settings, and examples of shape resonant behavior in more complex cases, which form current challenges in this field.

Dehmer, J.L.

1984-01-01T23:59:59.000Z

219

Shape resonances in molecular fields  

SciTech Connect

A shape resonance is a quasibound state in which a particle is temporarily trapped by a potential barrier (i.e., the shape of the potential), through which it may eventually tunnel and escape. This simple mechanism plays a prominent role in a variety of excitation processes in molecules, ranging from vibrational excitation by slow electrons to ionization of deep core levels by x-rays. Moreover, their localized nature makes shape resonances a unifying link between otherwise dissimilar circumstances. One example is the close connection between shape resonances in electron-molecule scattering and in molecular photoionization. Another is the frequent persistence of free-molecule shape resonant behavior upon adsorption on a surface or condensation into a molecular solid. The main focus of this article is a discussion of the basic properties of shape resonances in molecular fields, illustrated by the more transparent examples studied over the last ten years. Other aspects to be discussed are vibrational effects of shape resonances, connections between shape resonances in different physical settings, and examples of shape resonant behavior in more complex cases, which form current challenges in this field.

Dehmer, J.L.

1984-01-01T23:59:59.000Z

220

Stochastic Resonance in Washboard Potentials  

E-Print Network (OSTI)

We study the mobility of an overdamped particle in a periodic potential tilted by a constant force. The mobility exhibits a stochastic resonance in inhomogeneous systems with space dependent friction coefficient. The result indicates that the presence of oscillating external field is not essential for the observability of stochastic resonance, at least in the inhomogenous medium. I.

Debasis Dan A; Mangal C. Mahato; A. M. Jayannavar B

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

3D Visualization and interaction with spatiotemporal X-ray data to minimize radiation in image-guided surgery  

Science Conference Proceedings (OSTI)

Image-guided surgery (IGS) often depends on X-ray imaging, since pre-operative MRI, CT and PET scans do not provide an up-to-date internal patient view during the operation. X-rays introduce hazardous radiation, but long exposures for monitoring are ... Keywords: 3D cloud, 3D visualization, spatiotemporal X-ray data, radiation, image-guided surgery, X-ray imaging, prototype IGS system, motion tracking system, interactive visualization, 2D X-rays

F. Ioakeimidou; A. Olwal; A. Nordberg; H. von Holst

2011-06-01T23:59:59.000Z

222

Transverse-longitudinal integrated resonator  

DOE Patents (OSTI)

A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

Hutchinson, Donald P [Knoxville, TN; Simpson, Marcus L [Knoxville, TN; Simpson, John T [Knoxville, TN

2003-03-11T23:59:59.000Z

223

Delta connected resonant snubber circuit  

SciTech Connect

A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Lai, Jih-Sheng (Knoxville, TN); Peng, Fang Zheng (Oak Ridge, TN); Young, Sr., Robert W. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN)

1998-01-01T23:59:59.000Z

224

Delta connected resonant snubber circuit  

DOE Patents (OSTI)

A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.

Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.

1998-01-20T23:59:59.000Z

225

Imaging a laser pulse propagation trough an image acquisition system  

Science Conference Proceedings (OSTI)

The goal of this paper is to generate a laser pulse and to capture it by an image acquisition system. We use a confocal resonator to generate a laser pulse; then the generate light is focused in to an optical fiber using an achromatic doublet; the light ... Keywords: Hermite Gaussian polynomial, Laplacian filter, MTF, PSF, achromatic doublet, amplitude filter, bilateral filter, fixed pattern noise, photon shot noise

Toadere Florin; Nikos E. Mastorakis

2009-12-01T23:59:59.000Z

226

Auxiliary resonant DC tank converter  

SciTech Connect

An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

Peng, Fang Z. (Knoxville, TN)

2000-01-01T23:59:59.000Z

227

Argonne CNM Highlight: Nanomechanical Resonator Self-Assembled from  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanomechanical Resonator Self-Assembled from Nanoparticles Nanomechanical Resonator Self-Assembled from Nanoparticles thermal motion of self-assembled membranes Power spectral distribution of the thermal motion of membranes self-assembled from gold nanoparticles taken at the center (black) and halfway along the radius (red) in air; inset shows TEM images of the membranes Membrane motion under mechanical excitation Phase-sensitive image of one mode of membrane motion under mechanical excitation. The self-assembly of nanoscale structures from functional nanoparticles has provided a powerful path to developing devices with emergent properties from the bottom up. Users from the University of Chicago, together with researchers from the University of Melbourne and CNM's Electronic & Magnetic Materials & Devices Group, demonstrate that free-standing sheets

228

Calibration of fluorescence resonance energy transfer in microscopy  

DOE Patents (OSTI)

Imaging hardware, software, calibrants, and methods are provided to visualize and quantitate the amount of Fluorescence Resonance Energy Transfer (FRET) occurring between donor and acceptor molecules in epifluorescence microscopy. The MicroFRET system compensates for overlap among donor, acceptor, and FRET spectra using well characterized fluorescent beads as standards in conjunction with radiometrically calibrated image processing techniques. The MicroFRET system also provides precisely machined epifluorescence cubes to maintain proper image registration as the sample is illuminated at the donor and acceptor excitation wavelengths. Algorithms are described that pseudocolor the image to display pixels exhibiting radiometrically-corrected fluorescence emission from the donor (blue), the acceptor (green) and FRET (red). The method is demonstrated on samples exhibiting FRET between genetically engineered derivatives of the Green Fluorescent Protein (GFP) bound to the surface of Ni chelating beads by histidine-tags.

Youvan, Douglas C. (San Jose, CA); Silva, Christopher M. (Sunnyvale, CA); Bylina, Edward J. (San Jose, CA); Coleman, William J. (Moutain View, CA); Dilworth, Michael R. (Santa Cruz, CA); Yang, Mary M. (San Jose, CA)

2002-09-24T23:59:59.000Z

229

Nuclear Resonance Fluorescence for Materials Assay  

E-Print Network (OSTI)

et al. “Investigation of Nuclear Structure by Resonance1996, pp. G. Warren et al. “Nuclear Resonance Fluorescenceof 235U” IEEE Nuclear Science Symposium 2006, pp. 914. W.

Quiter, Brian J.

2010-01-01T23:59:59.000Z

230

Nuclear Resonance Fluorescence for Materials Assay  

E-Print Network (OSTI)

clandestine material with nuclear resonance fluorescence”.E. Norman, UC Berkeley Dept. of Nuclear Engineering, privatepp. 349. G. Warren et al. “Nuclear Resonance Fluorescence of

Quiter, Brian

2010-01-01T23:59:59.000Z

231

Multiple resonant railgun power supply  

DOE Patents (OSTI)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

232

Resonant Excitation of Plasma Wakefields  

SciTech Connect

We describe characteristics of the bunch train and plasma source used in a resonant plasma wakefield experiment at the Brookhaven National Laboratory Accelerator Test Facility. The bunch train has the proper correlated spread to unambiguously observe the expected energy gain by the witness bunch at resonance. The plasma density in the capillary discharge is sufficiently high to reach the resonance with the typical bunch train spacing of this experiment. It is also uniform over more than 3/4 of the 2 cm-long capillary.

Muggli, P.; Allen, B. [University of Southern California, Los Angeles, CA 90089 (United States); Yakimenko, V.; Fedurin, M.; Kusche, K.; Babzien, M. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

2010-11-04T23:59:59.000Z

233

Multiple resonant railgun power supply  

DOE Patents (OSTI)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, E.M.; Nunnally, W.C.

1985-06-19T23:59:59.000Z

234

Magnetic resonance detection: spectroscopy and imaging of lab ...  

Department of Chemistry, University of California, Berkeley, CA, 94720, USA. E-mail: elharel@berkeley.edu; Tel: +1 510 642 2094

235

Magnetic resonance detection: spectroscopy and imaging of lab ...  

ley in Physical Chemistry under the guidance of Alex Pines in the spring of 2008. His research focus at Berkeley was in devel-oping novel detection ...

236

Magnetic resonance imaging with an optical atomic magnetometer  

p rep o larizatio n an d arrivin g at th e d etectio n regio n , as th e p o larizatio n o f w ater relaxes exp o n en tially d u rin g th is p erio d .

237

Magnetic resonance imaging of polymer electrolytes and insertion electrodes.  

DOE Green Energy (OSTI)

This program seeks to better define electrode-electrolyte interfaces and solid-state ion transport mechanisms that are a central feature of fuel cells and advanced electrochemical systems. The goal is to develop a new generation of materials with enhanced energy efficiency and reduced tendency toward dendrite or passive film formation at the electrode-electrolyte interface.

Gerald, R. E., II; Klingler, R. J.; Rathke, J. W.

1999-05-19T23:59:59.000Z

238

A micro-machined resonator  

DOE Patents (OSTI)

This invention is comprised of a micro-machined resonator, typically quartz, with upper and lower micromachinable support members, or covers, having etched wells which may be lined with conductive electrode material, between the support members is a quartz resonator having an energy trapping quartz mesa capacitively coupled to the electrodes through a diaphragm; the quartz resonator is supported by either micro-machined cantilever springs or by thin layers extending over the surfaces of the support. If the diaphragm is rigid, clock applications are available, and if the diaphragm is resilient, then transducer applications can be achieved. Either the thin support layers or the conductive electrode material can be integral with the diaphragm. In any event, the covers are bonded to form a hermetic seal and the interior volume may be filled with a gas or may be evacuated. In addition, one or both of the covers may include oscillator and interface circuitry for the resonator.

Godshall, N.A.; Koehler, D.R.; Liang, A.Y.; Smith, B.K.

1991-12-31T23:59:59.000Z

239

Distribution of neutron resonance widths  

E-Print Network (OSTI)

Recent data on neutron resonance widths indicate disagreement with the Porter-Thomas distribution (PTD). I discuss the theoretical arguments for the PTD, possible theoretical modifications, and I summarize the experimantal evidence.

Hans A. Weidenmueller

2011-10-28T23:59:59.000Z

240

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Title: Carbon Nanotube Measurements. Description: Scanning electron microscope image of 'cleaned' carbon nanotubes at NIST (color added for ...

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Description: Engineering design image shows a cross-section of part of the planned ITER fusion reaction vessel. Diverter ...

242

BRIEF COMMUNICATION A 7 Tesla fMRI Study of Amygdala Responses to Fearful Faces  

E-Print Network (OSTI)

BRIEF COMMUNICATION A 7 Tesla fMRI Study of Amygdala Responses to Fearful Faces Wietske van der field strength. In this study, the feasibility of fMRI in the amygdalae at 7 Tesla was investigated in a fearful face depends on stimulus duration. Keywords Amygdala Á fMRI Á 7 Tesla Á Fear Á Face perception

Hadjikhani, Nouchine

243

Tubular Surface Evolution for Segmentation of the Cingulum Bundle From DW-MRI  

E-Print Network (OSTI)

Tubular Surface Evolution for Segmentation of the Cingulum Bundle From DW-MRI Vandana Mohan1 Diffusion-Weighted Imagery (DW-MRI) of the brain. The CB is a tube-like structure in the brain, but vary globally. Standard region-based segmentation tech- niques adapted to DW-MRI are not suitable here

Paris-Sud XI, Université de

244

Phosphorus-31 MRI of hard and soft solids using quadratic echo line-narrowing  

E-Print Network (OSTI)

Phosphorus-31 MRI of hard and soft solids using quadratic echo line-narrowing Merideth A. Freya gradients in sync with this line-narrowing sequence offers a fresh approach to carry out MRI of hard). Extending the reach of MRI to the study of other elements, and to hard or soft solids, opens new frontiers

Haller, Gary L.

245

Reproducibility of Interfraction Lung Motion Probability Distribution Function Using Dynamic MRI: Statistical Analysis  

SciTech Connect

Purpose: To investigate the statistical reproducibility of craniocaudal probability distribution function (PDF) of interfraction lung motion using dynamic magnetic resonance imaging. Methods and Materials: A total of 17 subjects, 9 healthy volunteers and 8 lung tumor patients, underwent two to three continuous 300-s magnetic resonance imaging scans in the sagittal plane, repeated 2 weeks apart. Three pulmonary vessels from different lung regions (upper, middle, and lower) in the healthy subjects and lung tumor patients were selected for tracking, and the displacement PDF reproducibility was evaluated as a function of scan time and frame rate. Results: For both healthy subjects and patients, the PDF reproducibility improved with increased scan time and converged to an equilibrium state during the 300-s scan. The PDF reproducibility at 300 s (mean, 0.86; range, 0.70-0.96) were significantly (p < 0.001) increased compared with those at 5 s (mean, 0.65; range, 0.25-0.79). PDF reproducibility showed less sensitivity to imaging frame rates that were >2 frames/s. Conclusion: A statistically significant improvement in PDF reproducibility was observed with a prolonged scan time among the 17 participants. The confirmation of PDF reproducibility over times much shorter than stereotactic body radiotherapy delivery duration is a vital part of the initial validation process of probability-based treatment planning for stereotactic body radiotherapy for lung cancer.

Cai Jing; Read, Paul W.; Larner, James M. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Jones, David R. [Department of Surgery, University of Virginia, Charlottesville, VA (United States); Benedict, Stanley H. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Sheng Ke [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)], E-mail: ks2mc@virginia.edu

2008-11-15T23:59:59.000Z

246

Micro-machined resonator oscillator  

DOE Patents (OSTI)

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a telemetered sensor beacon'' that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20--100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available. 21 figs.

Koehler, D.R.; Sniegowski, J.J.; Bivens, H.M.; Wessendorf, K.O.

1994-08-16T23:59:59.000Z

247

Micro-machined resonator oscillator  

DOE Patents (OSTI)

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

Koehler, Dale R. (Albuquerque, NM); Sniegowski, Jeffry J. (Albuquerque, NM); Bivens, Hugh M. (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM)

1994-01-01T23:59:59.000Z

248

Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials  

DOE Patents (OSTI)

Method comprising obtaining an NMR measurement from a sample wherein an ultra-low field NMR system probes the sample and produces the NMR measurement and wherein a sampling temperature, prepolarizing field, and measurement field are known; detecting the NMR measurement by means of inductive coils; analyzing the NMR measurement to obtain at least one measurement feature wherein the measurement feature comprises T1, T2, T1.rho., or the frequency dependence thereof; and, searching for the at least one measurement feature within a database comprising NMR reference data for at least one material to determine if the sample comprises a material of interest.

Matlashov, Andrei Nikolaevich; Urbaitis, Algis V.; Savukov, Igor Mykhaylovich; Espy, Michelle A.; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry

2013-03-05T23:59:59.000Z

249

Microelectromechanical resonator and method for fabrication  

DOE Patents (OSTI)

A method is disclosed for the robust fabrication of a microelectromechanical (MEM) resonator. In this method, a pattern of holes is formed in the resonator mass with the position, size and number of holes in the pattern being optimized to minimize an uncertainty .DELTA.f in the resonant frequency f.sub.0 of the MEM resonator due to manufacturing process variations (e.g. edge bias). A number of different types of MEM resonators are disclosed which can be formed using this method, including capacitively transduced Lame, wineglass and extensional resonators, and piezoelectric length-extensional resonators.

Wittwer, Jonathan W. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2009-11-10T23:59:59.000Z

250

A DUAL MODALITY SYSTEM FOR HIGH RESOLUTION -TRUE CONDUCTIVITY IMAGING  

E-Print Network (OSTI)

the difference between the current densities calculated based on the potential and the magnetic field Resonance Current Density Imaging (MRCDI) has been proposed to image current density and magnetic flux the current density at dc and RF frequency (Scoot et al 1995). Using MRCDI, the magnetic flux density

Eyüboðlu, Murat

251

Stochastic Resonance: from climate to biology  

E-Print Network (OSTI)

In this paper I will review some basic aspects of the mechanism of stochastic resonance. Stochastic resonance was first introduced as a possible mechanism to explain long term climatic variation. Since then, there have been many applications of stochastic resonance in physical and biological systems. I will show that in complex system, stochastic resonance can substantially change as a function of the ``system complexity''. Also, I will briefly mention how to apply stochastic resonance for the case of Brownian motors.

Roberto Benzi

2007-02-05T23:59:59.000Z

252

Image Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Mosaic of earth and sky images Mosaic of earth and sky images Image Resources Free image resources covering energy, environment, and general science. Here are some links to energy- and environment-related photographic databases. Berkeley Lab Photo Archive Berkeley Lab's online digital image collection. National Science Digital Library (NSDL) NSDL is the Nation's online library for education and research in science, technology, engineering, and mathematics. The World Bank Group Photo Library A distinctive collection of over 11,000 images that illustrate development through topics such as Agriculture, Education, Environment, Health, Trade and more. Calisphere Compiles the digital collections of libraries, museums, and cultural heritage organizations across California, and organizes them by theme, such

253

Available Technologies: High Frequency Abacus Nanotube Resonator  

Energy Efficiency; Energy Storage and Recovery; Renewable Energy; Environmental Technologies. Monitoring and Imaging; Remediation; Modeling; Imaging ...

254

Resonant Tunneling Device Logic Circuits  

E-Print Network (OSTI)

This report is a summary of the activities in the field of resonant tunneling device circuit design. The presented work has been performed by the Department of Microelectronics of the University of Dortmund (UNIDO) and the Solid-State Electronics Department of the Gerhard-Mercator University of Duisburg (GMUD) during the first year of the Microelectronics Advanced Research Initiative projects ANSWERS (Autonomous Nanoelectronic Systems with Extended Replication and Signalling) and LOCOM (Logic Circuits with Reduced Complexity based on Devices with Higher Functionality). As part of the ANSWERS work-package the principal task of UNIDO is to investigate novel logic circuit architectures for resonant tunneling devices, to perform circuit simulations, and to specify the electrical device parameters. The basic device configuration is a monolithically integrated resonant tunneling diode heterostructure field-effect transistor (RTD-HFET). This device and the demonstrator circuits are fabricated by the LOCOM partner GMUD.

Christian Pacha; Peter Glösekötter; Karl Goser; Werner Prost; Uwe Auer; Franz-J. Tegude

1999-01-01T23:59:59.000Z

255

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... on the availability of this image. Title: Tiny Tubes May Aid Pharmacuetical R&D. Description: NIST scientists used pairs of ...

256

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Magneto-optical image of magnetic fields within a YBCO superconductor showing electrically ... PHY, High-Temp Superconductors See also http ...

257

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... Title: New Imaging Tool is Boon to Fuel Cell Research. ... water being produced and removed inside the maze-like solid housing of fuel cells under a ...

258

Parametric coupling between macroscopic quantum resonators  

E-Print Network (OSTI)

Time-dependent linear coupling between macroscopic quantum resonator modes generates both a parametric amplification also known as a {}"squeezing operation" and a beam splitter operation, analogous to quantum optical systems. These operations, when applied properly, can robustly generate entanglement and squeezing for the quantum resonator modes. Here, we present such coupling schemes between a nanomechanical resonator and a superconducting electrical resonator using applied microwave voltages as well as between two superconducting lumped-element electrical resonators using a r.f. SQUID-mediated tunable coupler. By calculating the logarithmic negativity of the partially transposed density matrix, we quantitatively study the entanglement generated at finite temperatures. We also show that characterization of the nanomechanical resonator state after the quantum operations can be achieved by detecting the electrical resonator only. Thus, one of the electrical resonator modes can act as a probe to measure the entanglement of the coupled systems and the degree of squeezing for the other resonator mode.

L. Tian; M. S. Allman; R. W. Simmonds

2006-06-29T23:59:59.000Z

259

Argonne CNM News: Surface Plasmon Resonance in Interfaced Heterodimers  

NLE Websites -- All DOE Office Websites (Extended Search)

Surface Plasmon Resonance in Interfaced Heterodimers Surface Plasmon Resonance in Interfaced Heterodimers Silver and gold nanoparticle heterodiimers Silver and gold nanoparticle heterodimers (about 10 nm across); green wavy lines represent surfactant molecules in the schematic. Underlying is a TEM image of gold (golden color) and silver (dark gray) nanoparticles after epitaxial overgrowth for 180 sec. High-quality interfaced Au-Ag heterodimers in the quantum size regime (diameter <10 nm) were synthesized through a seed-mediated, surface-confined epitaxial overgrowth strategy by researchers in the Nanophotonics Group. First-principles calculations by the Theory & Modeling Group confirmed that quantum size effects and formation of Au/Ag interfaces lead to an unusual enhancement of the characteristic gold surface plasmon

260

Nanometric Optical Imaging Frontiers in Chemical Imaging  

E-Print Network (OSTI)

Nanometric Optical Imaging Frontiers in Chemical Imaging Seminar Series Presented by... Professor thermal imaging, chemical delivery and other new horizons. Finally, as part of this lecture, Lewis

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Images, Video, & More  

NLE Websites -- All DOE Office Websites (Extended Search)

Images, Video, & More Images BABAR Design drawings SLAC Image Gallery: BABAR SLAC Image Gallery: Aerial photos Videos Public lecture on "ANTIMATTER: What is it and where did it...

262

Second Harmonic Resonance for Equatorial Waves  

Science Conference Proceedings (OSTI)

Simple, exact analytical conditions for second harmonic resonance between equatorial waves are derived. Such resonance can occur only between two Rossby waves or two westward travelling gravity waves. It is shown that regardless of whether the ...

John P. Boyd

1983-03-01T23:59:59.000Z

263

Dissociative electron attachment to carbon dioxide via the ^2\\Pi_u shape resonance  

E-Print Network (OSTI)

Momentum imaging measurements from two experiments are presented and interpreted with the aid of new ab initio theoretical calculations to describe the dissociative electron attachment (DEA) dynamics. We address the problem of how the 4 eV ^2\\Pi_u shape resonance in CO_2 proceeds to dissociate to CO(^1\\Sigma^+) + O^-(^2P) by DEA.

Moradmand, A; Haxton, D J; Rescigno, T N; McCurdy, C W; Weber, Th; Matsika, Spiridoula; Landers, A L; Belkacem, A; Fogle, M

2013-01-01T23:59:59.000Z

264

Dissociative Electron Attachment to Carbon Dioxide via the 8.2 eV Feshbach resonance  

SciTech Connect

Momentum imaging experiments on dissociative electron attachment (DEA) to CO{sub 2} are combined with the results of ab initio calculations to provide a detailed and consistent picture of the dissociation dynamics through the 8.2 eV resonance, which is the major channel for DEA in CO{sub 2}. The present study resolves several puzzling misconceptions about this system.

Slaughter, Dan; Adaniya, Hidihito; Rescigno, Tom; Haxton, Dan; Orel, Ann; McCurdy, Bill; Belkacem, Ali

2011-08-17T23:59:59.000Z

265

Nuclear Resonance Fluorescence at MIT | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Resonance Fluorescence at MIT Resonance Fluorescence at MIT Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Nuclear Resonance Fluorescence at MIT Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Material Identification and Object Imaging Using Nuclear Resonance Fluorescence Developed at: Massachusetts Institute of Technology

266

Multi-probe robotic positioner for cryoablation in MRI  

E-Print Network (OSTI)

This thesis describes the design of a guidance device for faster and more accurate targeting of multiple probes during cryoablation and other percutaneous interventions performed in closed bore magnetic resonance (MR) ...

Wu, Faye Y

2012-01-01T23:59:59.000Z

267

Resonant Power Conditioning and Compact Pulse Power ...  

Science Conference Proceedings (OSTI)

... (FEEDBACK) HV RECTIFIER AND FILTER NETWORK ... Los Alamos High Frequency “Polyphase Resonant Power Conditioning” ... 30 KW Loss ...

2012-10-31T23:59:59.000Z

268

Theory of atomic motion in resonant radiation  

SciTech Connect

Atomic motion in resonant and near resonant electromagnetic radiation is investigated theoretically. The exposition begins with a study of atomic motion in a resonant standing light wave, with a view toward isotope separation by selective photodeflection, and proceeds to the investigation of more general problems of atomic motion in resonant radiation. The body of the work consists of six chapters, each of which was prepared as a manuscript for publication in the open literature.

Cook, R.J.

1980-03-01T23:59:59.000Z

269

Wireless Energy Transfer Using Magnetic Resonance  

Science Conference Proceedings (OSTI)

In 1899, Nikola Tesla, who had devised a type of resonant transformer called the Tesla coil, achieved a major breakthrough in his work by transmitting 100 million volts of electric power wirelessly over a distance of 26 miles to light up a bank of 200 ... Keywords: wireless energy transfer, near field, evanescent wave, magnetic resonance, self-resonance

Rohan Bhutkar; Sahil Sapre

2009-12-01T23:59:59.000Z

270

Estimation of cardiac hyperelastic material properties from MRI tissue tagging and diffusion tensor imaging  

Science Conference Proceedings (OSTI)

The passive material properties of myocardium are important in the understanding of diastolic cardiac dysfunction. We determined hyperelastic myocardial material parameters in four isolated arrested pig hearts undergoing passive inflation of the left ...

Kevin F. Augenstein; Brett R. Cowan; Ian J. LeGrice; Alistair A. Young

2006-10-01T23:59:59.000Z

271

Combined diffuse optical tomography (DOT) and MRI system for cancer imaging in small animals  

E-Print Network (OSTI)

8, 2006 Technology in Cancer Research & Treatment, Volume 5,Technology in Cancer Research & Treatment, Volume 5, Number1161- Technology in Cancer Research & Treatment, Volume 5,

Gulsen, Gultekin; Birgul, Ozlem; Unlu, Mehmet Burcin; Shafiiha, Roshanak; Nalcioglu, Orhan

2006-01-01T23:59:59.000Z

272

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... from the bright glare in the distance transmit images of a cat-like face at ... Though false color has been added to the cats faces, they are otherwise ...

273

NIST Image Gallery: Image Details  

Science Conference Proceedings (OSTI)

... a href http://www.nist.gov/public_affairs/images/Nanopore 20device.avi See video /a PHY, DARPA, spectroscopy See also http://www.nist.gov/pml ...

274

Iron/Iron Oxide Core/Shell Nanoparticles for MRI and Magnetic ...  

Science Conference Proceedings (OSTI)

Bulk Nanoceramics and Nanocomposites: Processed by Pulsed Electric Current ... Iron/Iron Oxide Core/Shell Nanoparticles for MRI and Magnetic Hyperthermia.

275

Synthesis and bioconjugation of gold nanoparticles as potential molecular probes for light-based imaging techniques  

Science Conference Proceedings (OSTI)

We have synthesized and characterized gold nanoparticles (spheres and rods) with optical extinction bands within the "optical imaging window." The intense plasmon resonant driven absorption and scattering peaks of these nanoparticles make them suitable ...

Raja Gopal Rayavarapu; Wilma Petersen; Constantin Ungureanu; Janine N. Post; Ton G. van Leeuwen; Srirang Manohar

2007-01-01T23:59:59.000Z

276

Resonant Relaxation in Electroweak Baryogenesis  

E-Print Network (OSTI)

We compute the leading, chiral charge-changing relaxation term in the quantum transport equations that govern electroweak baryogenesis using the closed time path formulation of non-equilibrium quantum field theory. We show that the relaxation transport coefficients may be resonantly enhanced under appropriate conditions on electroweak model parameters and that such enhancements can mitigate the impact of similar enhancements in the CP-violating source terms. We also develop a power counting in the time and energy scales entering electroweak baryogenesis and include effects through second order in ratios $\\epsilon$ of the small and large scales. We illustrate the implications of the resonantly enhanced ${\\cal O}(\\epsilon^2)$ terms using the Minimal Supersymmetric Standard Model, focusing on the interplay between the requirements of baryogenesis and constraints obtained from collider studies, precision electroweak data, and electric dipole moment searches.

Lee, C; Ramsey-Musolf, M J; Lee, Christopher; Cirigliano, Vincenzo; Ramsey-Musolf, Michael J.

2004-01-01T23:59:59.000Z

277

Resonant Relaxation in Electroweak Baryogenesis  

E-Print Network (OSTI)

We compute the leading, chiral charge-changing relaxation term in the quantum transport equations that govern electroweak baryogenesis using the closed time path formulation of non-equilibrium quantum field theory. We show that the relaxation transport coefficients may be resonantly enhanced under appropriate conditions on electroweak model parameters and that such enhancements can mitigate the impact of similar enhancements in the CP-violating source terms. We also develop a power counting in the time and energy scales entering electroweak baryogenesis and include effects through second order in ratios $\\epsilon$ of the small and large scales. We illustrate the implications of the resonantly enhanced ${\\cal O}(\\epsilon^2)$ terms using the Minimal Supersymmetric Standard Model, focusing on the interplay between the requirements of baryogenesis and constraints obtained from collider studies, precision electroweak data, and electric dipole moment searches.

Christopher Lee; Vincenzo Cirigliano; Michael J. Ramsey-Musolf

2004-12-23T23:59:59.000Z

278

Hadronic Resonances from Lattice QCD  

Science Conference Proceedings (OSTI)

The determination of the pattern of hadronic resonances as predicted by Quantum Chromodynamics requires the use of non-perturbative techniques. Lattice QCD has emerged as the dominant tool for such calculations, and has produced many QCD predictions which can be directly compared to experiment. The concepts underlying lattice QCD are outlined, methods for calculating excited states are discussed, and results from an exploratory Nucleon and Delta baryon spectrum study are presented.

John Bulava; Robert Edwards; George Fleming; K. Jimmy Juge; Adam C. Lichtl; Nilmani Mathur; Colin Morningstar; David Richards; Stephen J. Wallace

2007-06-16T23:59:59.000Z

279

Ring resonant cavities for spectroscopy  

DOE Patents (OSTI)

Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

1999-06-15T23:59:59.000Z

280

Mathematical morphology for matrix fields induced by the Loewner ordering in higher dimensions  

Science Conference Proceedings (OSTI)

Positive semidefinite matrix fields are becoming increasingly important in digital imaging. One reason for this tendency is the introduction of diffusion tensor magnetic resonance imaging (DT-MRI). In order to perform shape analysis, enhancement or segmentation ... Keywords: Closing, DT-MRI, Dilation, Erosion, Loewner ordering, Mathematical morphology, Matrix-valued imaging, Mid-range filter, Morphological derivatives, Opening, Shock filter, Top hats

Bernhard Burgeth; Andres Bruhn; Nils Papenberg; Martin Welk; Joachim Weickert

2007-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

History Images  

NLE Websites -- All DOE Office Websites (Extended Search)

History Images History Images Los Alamos History in Images Los Alamos has a proud history and heritage of almost 70 years of science and innovation. The people of the Laboratory work on advanced technologies to provide the best scientific and engineering solutions to many of the nation's most crucial security challenges. Click thumbnails to enlarge. Photos arranged by most recent first, horizontal formats before vertical. See Flickr for more sizes and details. Back in the day Back in the day LA bridge in Los Alamos LA bridge in Los Alamos 1945 Army-Navy "E" Award 1945 Army-Navy "E" Award Louis Rosen Louis Rosen Bob Van Ness Robert Kuckuck and Michael Anastasio Bob Van Ness Robert Kuckuck and Michael Anastasio TA-18 TA-18 Elmer Island TU-4 assembly area Elmer Island TU-4 assembly area

282

Methods for magnetic resonance analysis using magic angle technique  

DOE Patents (OSTI)

Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.

Hu, Jian Zhi (Richland, WA); Wind, Robert A. (Kennewick, WA); Minard, Kevin R. (Kennewick, WA); Majors, Paul D. (Kennewick, WA)

2011-11-22T23:59:59.000Z

283

Optical imaging correlates with magnetic resonance imaging breast density and reveals composition changes during neoadjuvant chemotherapy  

E-Print Network (OSTI)

chemotherapy. Breast Cancer Research 2013 15:R14. SubmitSullivan et al. Breast Cancer Research 2013, 15:R14 http://Sullivan et al. Breast Cancer Research 2013, 15:R14 http://

2013-01-01T23:59:59.000Z

284

Neutron Resonance Radiography for Explosives Detection: Technical Challenges  

DOE Green Energy (OSTI)

Fast Neutron Resonance Radiography (NRR) has recently become a focus of investigation as a supplement to conventional x-ray systems as a non-invasive, non-destructive means of detecting explosive material concealed in checked luggage or cargo containers at airports. Using fast (1-6 MeV) neutrons produced by the D(d,n){sup 3}He reaction, NRR provides both an imaging capability and the ability to determine the chemical composition of materials in baggage or cargo. Elemental discrimination is achieved by exploiting the resonance features of the neutron cross-section for oxygen, nitrogen, carbon, and hydrogen. Simulations have shown the effectiveness of multiple-element NRR through Monte Carlo transport methods; this work is focused on the development of a prototype system that will incorporate an accelerator-based neutron source and a neutron detection and imaging system to demonstrate the realistic capabilities of NRR in distinguishing the elemental components of concealed objects. Preliminary experiments have exposed significant technical difficulties unapparent in simulations, including the presence of image contamination from gamma ray production, the detection of low-fluence fast neutrons in a gamma field, and the mechanical difficulties inherent in the use of thin foil windows for gas cell confinement. To mitigate these concerns, a new gas target has been developed to simultaneously reduce gamma ray production and increase structural integrity in high flux gas targets. Development of a neutron imaging system and neutron counting based on characteristic neutron pulse shapes have been investigated as a means of improving signal to noise ratios, reducing irradiation times, and increasing the accuracy of elemental determination.

Raas, W L; Blackburn, B; Boyd, E; Hall, J M; Kohse, G; Lanza, R; Rusnak, B; Watterson, J W

2005-11-09T23:59:59.000Z

285

Imaging of quantum Hall states in ultracold atomic gases  

SciTech Connect

We examine off-resonant light scattering from ultracold atoms in the quantum Hall regime. When the light scattering is spin dependent, we show that images formed in the far field can be used to distinguish states of the system. The spatial dependence of the far-field images is determined by the two-particle spin-correlation functions, which the images are related to by a transformation. Quasiholes in the system appear in images of the density formed by collecting the scattered light with a microscope, where the quasihole statistics are revealed by the reduction in density at the quasihole position.

Douglas, James S.; Burnett, Keith [University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)

2011-11-15T23:59:59.000Z

286

Future Changes in Tropical Cyclone Activity Projected by the New High-Resolution MRI-AGCM  

Science Conference Proceedings (OSTI)

New versions of the high-resolution 20- and 60-km-mesh Meteorological Research Institute (MRI) atmospheric general circulation models (MRI-AGCM version 3.2) have been developed and used to investigate potential future changes in tropical cyclone (...

Hiroyuki Murakami; Yuqing Wang; Hiromasa Yoshimura; Ryo Mizuta; Masato Sugi; Eiki Shindo; Yukimasa Adachi; Seiji Yukimoto; Masahiro Hosaka; Shoji Kusunoki; Tomoaki Ose; Akio Kitoh

2012-05-01T23:59:59.000Z

287

Testing Oil Saturation Distribution in Migration Paths Using MRI1 Jianzhao Yan 1  

E-Print Network (OSTI)

- 1 - Testing Oil Saturation Distribution in Migration Paths Using MRI1 Jianzhao Yan 1 , Xiaorong media, and to measure oil and water saturation. Although this technique has great advantages compared14. Using15 MRI, the oil secondary migration paths are scanned to measure the saturation distribution during

Paris-Sud XI, Université de

288

Ultrasonic Imaging of Subsurface Objects Using Photorefractive Dynamic Holography  

SciTech Connect

The INEEL has developed a photorefractive ultrasonic imaging technology that records both phase and amplitude of ultrasonic waves on the surface of solids. Phase locked dynamic holography provides full field images of these waves scattered from subsurface defects in solids, and these data are compared with theoretical predictions. Laser light reflected by a vibrating surface is imaged into a photorefractive material where it is mixed in a heterodyne technique with a reference wave. This demodulates the data and provides an image of the ultrasonic waves in either 2 wave or 4 wave mixing mode. These data images are recorded at video frame rates and show phase locked traveling or resonant acoustic waves. This technique can be used over a broad range of ultrasonic frequencies. Acoustic frequencies from 2 kHz to 10 MHz have been imaged, and a point measuring (non-imaging) version of the system has measured picometer amplitudes at 1 GHz.

Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

2001-07-01T23:59:59.000Z

289

Photoproduction of proton antiproton resonances  

DOE Green Energy (OSTI)

Preliminary results are reported on the reaction {gamma}p {yields} pp{bar p}. The data were obtained at the Thomas Jefferson National Accelerator Facility utilizing the CLAS detector and a tagged photon beam of 4.8 to 5.2 GeV incident on a liquid hydrogen target. The focus of this study is to search for possible intermediate resonances which decay to {bar p}p. Both final state protons were detected in CLAS whereas the antiproton was identified via missing mass. General features of the accepted data are presented.

P. Eugenio

2004-08-01T23:59:59.000Z

290

Bio-Nano ECRIS: An electron cyclotron resonance ion source for new materials production  

Science Conference Proceedings (OSTI)

We developed an electron cyclotron resonance ion source (ECRIS) for new materials production on nanoscale. Our main target is the endohedral fullerenes, which have potential in medical care, biotechnology, and nanotechnology. In particular, iron-encapsulated fullerene can be applied as a contrast material for magnetic resonance imaging or microwave heat therapy. Thus, our new ECRIS is named the Bio-Nano ECRIS. In this article, the recent progress of the development of the Bio-Nano ECRIS is reported: (i) iron ion beam production using induction heating oven and (ii) optimization of singly charged C{sub 60} ion beam production.

Uchida, T. [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Minezaki, H. [Graduate School of Engineering, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Tanaka, K.; Asaji, T. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama, Toyama 930-1305 (Japan); Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Biri, S. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem Ter 18/c (Hungary); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Graduate School of Engineering, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan)

2010-02-15T23:59:59.000Z

291

System and method for regulating resonant inverters  

SciTech Connect

A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

Stevanovic, Ljubisa Dragoljub (Clifton Park, NY); Zane, Regan Andrew (Superior, CO)

2007-08-28T23:59:59.000Z

292

Imaging bolometer  

DOE Patents (OSTI)

Radiation-hard, steady-state imaging bolometer. A bolometer employing infrared (IR) imaging of a segmented-matrix absorber of plasma radiation in a cooled-pinhole camera geometry is described. The bolometer design parameters are determined by modeling the temperature of the foils from which the absorbing matrix is fabricated by using a two-dimensional time-dependent solution of the heat conduction equation. The resulting design will give a steady-state bolometry capability, with approximately 100 Hz time resolution, while simultaneously providing hundreds of channels of spatial information. No wiring harnesses will be required, as the temperature-rise data will be measured via an IR camera. The resulting spatial data may be used to tomographically investigate the profile of plasmas.

Wurden, Glen A. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

293

Imaging bolometer  

DOE Patents (OSTI)

Radiation-hard, steady-state imaging bolometer is disclosed. A bolometer employing infrared (IR) imaging of a segmented-matrix absorber of plasma radiation in a cooled-pinhole camera geometry is described. The bolometer design parameters are determined by modeling the temperature of the foils from which the absorbing matrix is fabricated by using a two-dimensional time-dependent solution of the heat conduction equation. The resulting design will give a steady-state bolometry capability, with approximately 100 Hz time resolution, while simultaneously providing hundreds of channels of spatial information. No wiring harnesses will be required, as the temperature-rise data will be measured via an IR camera. The resulting spatial data may be used to tomographically investigate the profile of plasmas. 2 figs.

Wurden, G.A.

1999-01-19T23:59:59.000Z

294

MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization  

E-Print Network (OSTI)

of Propane Gas . . . . . . . . . . . . . . . . . . . . k-B.2.2 Model Propane Spectrum for TemperatureSpectra of Propylene and Propane ALTADENA Polarized Images

Burt, Scott R

2008-01-01T23:59:59.000Z

295

Available Technologies: Portable, High Resolution NMR/MRI in ...  

Multidimensional imaging for medical diagnosis, ... The Berkeley Lab method combines elements of two previous inventions by the Pines research group, RF field ...

296

Progress towards understanding baryon resonances  

Science Conference Proceedings (OSTI)

The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1?2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have been performed in the heavy-baryon sector, which has seen a fruitful period in recent years, in particular at the B factories and the Tevatron. First results from the large hadron collider indicate rapid progress in the field of bottom baryons. In this review, we discuss the recent experimental progress and give an overview of theoretical approaches.

Crede, Volker [FSU; Roberts, Winston [FSU

2013-07-01T23:59:59.000Z

297

Ultrahig h F requency Nanotube Resonators  

A new combination of drive and detection methods ... mobility of static charges near the nanotube. The resonator serv es as an exceptionally sensiti ...

298

An analysis of perturbed confocal resonators.  

E-Print Network (OSTI)

??An analytical technique is developed for computing mode functions and associated diffraction losses of perturbed multimode optical resonators. It is based upon a consistent field… (more)

Asmus, John Fredrich

1965-01-01T23:59:59.000Z

299

Limits of Nanomechanical Resonators - Lawrence Berkeley ...  

communications technology and single-molecule detection schemes. Resonators with exceptionally high quality factors, Q, have been used for exotic physics ...

300

Resonant Polarized Radiation Catalysis, and the Expansion  

Science Conference Proceedings (OSTI)

Presentation Title, The Birth of a New Field of Materials Science: Resonant Polarized Radiation Catalysis, and the Expansion of Thermodynamics. Author(s)  ...

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Interplay of Resonant and Quasi-Resonant Interaction of the Directional Ocean Waves  

Science Conference Proceedings (OSTI)

Recent experimental study of the evolution of random directional gravity waves in deep water provides new insight into the nature of the spectral evolution of the ocean waves and the relative significance of resonant and quasi-resonant wave ...

Takuji Waseda; Takeshi Kinoshita; Hitoshi Tamura

2009-09-01T23:59:59.000Z

302

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Magnetic Lensless Imaging of Magnetic Nanostructures Lensless Imaging of Magnetic Nanostructures Print Wednesday, 28 March 2012 00:00 Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the first time to nanometer-scale magnetic structures in an alloy. Many Ways To See You open your eyes and detect the light rays streaming through your bedroom window (transmission), illuminating your socks on the floor (scattering). You put on your glasses (refraction) to detect the state of your image in the mirror (reflection). If you are an ALS scientist, perhaps you go to work and shine some x-ray light on a crystal to detect the arrangement of the atoms in the crystal (diffraction). Now, thanks to Turner et al., you can also shine some x-ray light on a magnetic sample to detect the arrangement of its electron spins through a method known as lensless imaging. This last example is an equally valid way to "see," but instead of using windows, lenses, or mirrors to manipulate light and construct an image, mathematical formulas are used to describe the effects that particles and fields in the sample have on the light. These formulas have always contained terms that relate to the electron spin of magnetic atoms, but they were previously ignored. Using the full formula allows for the determination of not only crystal structure, but magnetic spin distribution and orientation as well, with a spatial resolution limited only by the wavelength of x-rays used. This promising method can be used at any coherent light source, including modern x-ray free-electron lasers, where ultrashort pulses would freeze-frame magnetic changes, offering the potential for imaging in unprecedented detail the structure and motion of boundaries between regions with different magnetic orientation.

303

Simple Fully Automated Group Classification on Brain fMRI  

SciTech Connect

We propose a simple, well grounded classification technique which is suited for group classification on brain fMRI data sets that have high dimensionality, small number of subjects, high noise level, high subject variability, imperfect registration and capture subtle cognitive effects. We propose threshold-split region as a new feature selection method and majority voteas the classification technique. Our method does not require a predefined set of regions of interest. We use average acros ssessions, only one feature perexperimental condition, feature independence assumption, and simple classifiers. The seeming counter-intuitive approach of using a simple design is supported by signal processing and statistical theory. Experimental results in two block design data sets that capture brain function under distinct monetary rewards for cocaine addicted and control subjects, show that our method exhibits increased generalization accuracy compared to commonly used feature selection and classification techniques.

Honorio, J.; Goldstein, R.; Honorio, J.; Samaras, D.; Tomasi, D.; Goldstein, R.Z.

2010-04-14T23:59:59.000Z

304

Applications of Nuclear Resonance Fluorescence  

Science Conference Proceedings (OSTI)

Nuclear Resonance Fluorescence (NRF) has the potential of addressing a wide variety of applications, which require isotopic and/or elemental information about a sample. We have investigated a variety of non-proliferation applications that may be addressed by NRF. From these applications, we have selected two, measuring uranium enrichment in UF6 cylinders and material verification in dismantlement, to investigate in more detail. Analytical models have been developed to evaluate these applications, and test measurements have been conducted to validate those models. We found that it is unlikely with current technology to address the requirements for UF6 cylinder enrichment measurements. In contrast, NRF is a very promising approach for material verification for dismantlement.

Warren, Glen A.; Detwiler, Rebecca S.; Peplowski, Patrick N.

2010-11-11T23:59:59.000Z

305

Resilient microring resonator based photonic networks  

Science Conference Proceedings (OSTI)

Microring resonator-based photonic interconnects are being considered for both on-chip and off-chip communication in order to satisfy the power and bandwidth requirements of future large scale chip multiprocessors. However, microring resonators are prone ... Keywords: fault model, microring, photonic interconnect, resilience

Christopher J. Nitta; Matthew K. Farrens; Venkatesh Akella

2011-12-01T23:59:59.000Z

306

Method for fabricating a microelectromechanical resonator  

DOE Patents (OSTI)

A method is disclosed which calculates dimensions for a MEM resonator in terms of integer multiples of a grid width G for reticles used to fabricate the resonator, including an actual sub-width L.sub.a=NG and an effective electrode width W.sub.e=MG where N and M are integers which minimize a frequency error f.sub.e=f.sub.d-f.sub.a between a desired resonant frequency f.sub.d and an actual resonant frequency f.sub.a. The method can also be used to calculate an overall width W.sub.o for the MEM resonator, and an effective electrode length L.sub.e which provides a desired motional impedance for the MEM resonator. The MEM resonator can then be fabricated using these values for L.sub.a, W.sub.e, W.sub.o and L.sub.e. The method can also be applied to a number j of MEM resonators formed on a common substrate.

Wojciechowski, Kenneth E; Olsson, III, Roy H

2013-02-05T23:59:59.000Z

307

Integral data analysis for resonance parameters determination  

SciTech Connect

Neutron time-of-flight experiments have long been used to determine resonance parameters. Those resonance parameters have then been used in calculations of integral quantities such as Maxwellian averages or resonance integrals, and results of those calculations in turn have been used as a criterion for acceptability of the resonance analysis. However, the calculations were inadequate because covariances on the parameter values were not included in the calculations. In this report an effort to correct for that deficiency is documented: (1) the R-matrix analysis code SAMMY has been modified to include integral quantities of importance, (2) directly within the resonance parameter analysis, and (3) to determine the best fit to both differential (microscopic) and integral (macroscopic) data simultaneously. This modification was implemented because it is expected to have an impact on the intermediate-energy range that is important for criticality safety applications.

Larson, N.M.; Leal, L.C.; Derrien, H.

1997-09-01T23:59:59.000Z

308

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Magnetic Nanostructures Print Lensless Imaging of Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the first time to nanometer-scale magnetic structures in an alloy. Many Ways To See You open your eyes and detect the light rays streaming through your bedroom window (transmission), illuminating your socks on the floor (scattering). You put on your glasses (refraction) to detect the state of your image in the mirror (reflection). If you are an ALS scientist, perhaps you go to work and shine some x-ray light on a crystal to detect the arrangement of the atoms in the crystal (diffraction). Now, thanks to Turner et al., you can also shine some x-ray light on a magnetic sample to detect the arrangement of its electron spins through a method known as lensless imaging. This last example is an equally valid way to "see," but instead of using windows, lenses, or mirrors to manipulate light and construct an image, mathematical formulas are used to describe the effects that particles and fields in the sample have on the light. These formulas have always contained terms that relate to the electron spin of magnetic atoms, but they were previously ignored. Using the full formula allows for the determination of not only crystal structure, but magnetic spin distribution and orientation as well, with a spatial resolution limited only by the wavelength of x-rays used. This promising method can be used at any coherent light source, including modern x-ray free-electron lasers, where ultrashort pulses would freeze-frame magnetic changes, offering the potential for imaging in unprecedented detail the structure and motion of boundaries between regions with different magnetic orientation.

309

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Magnetic Nanostructures Print Lensless Imaging of Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the first time to nanometer-scale magnetic structures in an alloy. Many Ways To See You open your eyes and detect the light rays streaming through your bedroom window (transmission), illuminating your socks on the floor (scattering). You put on your glasses (refraction) to detect the state of your image in the mirror (reflection). If you are an ALS scientist, perhaps you go to work and shine some x-ray light on a crystal to detect the arrangement of the atoms in the crystal (diffraction). Now, thanks to Turner et al., you can also shine some x-ray light on a magnetic sample to detect the arrangement of its electron spins through a method known as lensless imaging. This last example is an equally valid way to "see," but instead of using windows, lenses, or mirrors to manipulate light and construct an image, mathematical formulas are used to describe the effects that particles and fields in the sample have on the light. These formulas have always contained terms that relate to the electron spin of magnetic atoms, but they were previously ignored. Using the full formula allows for the determination of not only crystal structure, but magnetic spin distribution and orientation as well, with a spatial resolution limited only by the wavelength of x-rays used. This promising method can be used at any coherent light source, including modern x-ray free-electron lasers, where ultrashort pulses would freeze-frame magnetic changes, offering the potential for imaging in unprecedented detail the structure and motion of boundaries between regions with different magnetic orientation.

310

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Magnetic Nanostructures Print Lensless Imaging of Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the first time to nanometer-scale magnetic structures in an alloy. Many Ways To See You open your eyes and detect the light rays streaming through your bedroom window (transmission), illuminating your socks on the floor (scattering). You put on your glasses (refraction) to detect the state of your image in the mirror (reflection). If you are an ALS scientist, perhaps you go to work and shine some x-ray light on a crystal to detect the arrangement of the atoms in the crystal (diffraction). Now, thanks to Turner et al., you can also shine some x-ray light on a magnetic sample to detect the arrangement of its electron spins through a method known as lensless imaging. This last example is an equally valid way to "see," but instead of using windows, lenses, or mirrors to manipulate light and construct an image, mathematical formulas are used to describe the effects that particles and fields in the sample have on the light. These formulas have always contained terms that relate to the electron spin of magnetic atoms, but they were previously ignored. Using the full formula allows for the determination of not only crystal structure, but magnetic spin distribution and orientation as well, with a spatial resolution limited only by the wavelength of x-rays used. This promising method can be used at any coherent light source, including modern x-ray free-electron lasers, where ultrashort pulses would freeze-frame magnetic changes, offering the potential for imaging in unprecedented detail the structure and motion of boundaries between regions with different magnetic orientation.

311

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Magnetic Nanostructures Print Lensless Imaging of Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the first time to nanometer-scale magnetic structures in an alloy. Many Ways To See You open your eyes and detect the light rays streaming through your bedroom window (transmission), illuminating your socks on the floor (scattering). You put on your glasses (refraction) to detect the state of your image in the mirror (reflection). If you are an ALS scientist, perhaps you go to work and shine some x-ray light on a crystal to detect the arrangement of the atoms in the crystal (diffraction). Now, thanks to Turner et al., you can also shine some x-ray light on a magnetic sample to detect the arrangement of its electron spins through a method known as lensless imaging. This last example is an equally valid way to "see," but instead of using windows, lenses, or mirrors to manipulate light and construct an image, mathematical formulas are used to describe the effects that particles and fields in the sample have on the light. These formulas have always contained terms that relate to the electron spin of magnetic atoms, but they were previously ignored. Using the full formula allows for the determination of not only crystal structure, but magnetic spin distribution and orientation as well, with a spatial resolution limited only by the wavelength of x-rays used. This promising method can be used at any coherent light source, including modern x-ray free-electron lasers, where ultrashort pulses would freeze-frame magnetic changes, offering the potential for imaging in unprecedented detail the structure and motion of boundaries between regions with different magnetic orientation.

312

A WWW interactive progressive local image transmission system  

E-Print Network (OSTI)

We present a JAVA-based Interactive Progressive Local Image Transmission (IPLIT) system for viewing large images over the bandwidth-limited World Wide Web (WWW) in "reasonable (i.e. usable) time". One motivation behind this research is the need for medical specialists to remotely view medical images, in reasonable time, over the WWW. In our IPLIT system, the user employs a JAVA-enabled Internet browser to view and browse a low resolution image. The identification of features or regions of interest before observing those regions in detail is performed by either selecting a particular region manually via mouse or by utilizing an automatic feature-detection mode. The automatic feature-detection displays high-resolution subimages along a trajectory determined by the user-specified feature of interest. Our program handles 3D image data as a sequence of 2D images. Our IPLIT system is tested on actual MRI, CT and Ultrasound medical images obtained from the Robarts Research Institute at the Un...

Tiffany-Emil Liptay John; John L. Barron; Irene Gargantini

1999-01-01T23:59:59.000Z

313

FM DANTE fast imaging and variations: emerging rf-based ultrafast imaging techniques  

Science Conference Proceedings (OSTI)

Keywords: DANTE fast imaging, NMR, burst imaging, fast chemical shift imaging, fast imaging, fast spectroscopic imaging, fast susceptibility imaging

Z. H. Cho; Y. M. Ro; I. K. Hong

1998-01-01T23:59:59.000Z

314

Inelastic X-ray and Nuclear Resonant Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Beamlines Divisions Argonne Home > Advanced Photon Source > Inelastic X-ray and Nuclear Resonant Scattering The Inelastic X-ray and Nuclear Resonant Scattering group...

315

Using Nuclear Resonance Fluorescence for Nondestructive Isotopic Analysis  

E-Print Network (OSTI)

7, (1959) pp. 54. [12] B.J. Quiter, ``Nuclear ResonanceFluorescence for Nuclear Materials Assay,'' University ofclandestine material with nuclear resonance fluorescence,"

Ludewigt, Bernhard A.

2010-01-01T23:59:59.000Z

316

Nondestructive Spent Fuel Assay Using Nuclear Resonance Fluorescence  

E-Print Network (OSTI)

09-01188, ANS Advances in Nuclear Fuel Management IV, Hiltonanalysis of spent nuclear fuel via nuclear resonanceNondestructive Spent Fuel Assay Using Nuclear Resonance

Quiter, Brian

2010-01-01T23:59:59.000Z

317

Internal Dielectric Transduction in Bulk-Mode Resonators  

E-Print Network (OSTI)

This paper investigates electrostatic transduction of a longitudinal-mode silicon acoustic resonator with internal dielectric films. Geometric optimization of internal dielectrically transduced resonators is derived ...

Weinstein, Dana

318

Cyclotron Resonances in Electron Cloud Dynamics  

SciTech Connect

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where lb<< 2pi c/omega c (with lb = bunch length, omega c = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the electron cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor ~;;3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined vertical density"stripes" found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The existence of the resonances has been confirmed in experiments at PEP-II. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations and experimental observations, the reason for the bunch-length dependence, and details of the dynamics are discussed here.

Celata, C. M.; Furman, Miguel A.; Vay, J.-L.; Ng, J. S.T.; Grote, D. P.; Pivi, M. T. F.; Wang, L. F.

2009-04-29T23:59:59.000Z

319

Resonant Tidal Disruption in Galactic Nuclei  

E-Print Network (OSTI)

It has recently been shown that the rate of angular momentum relaxation in nearly-Keplerian star clusters is greatly increased by a process termed resonant relaxation (Rauch & Tremaine 1996), who also argued that tidal disruption of stars in galactic nuclei containing massive black holes could be noticeably enhanced by this process. We describe here the results of numerical simulations of resonant tidal disruption which quantitatively test the predictions made by Rauch & Tremaine. The simulation method is based on an N-body routine incorporating cloning of stars near the loss cone and a semi-relativistic symplectic integration scheme. We also briefly describe the discovery of chaos in the Wisdom-Holman symplectic integrator applied to highly eccentric orbits and propose a modified integration scheme that remains robust under these conditions. We find that resonant disruption rates exceed their non-resonant counterparts by an amount consistent with the predictions; in particular, we estimate the net tidal disruption rate for a fully resonant cluster to be about twice that of its non-resonant counterpart. No significant enhancement in rates is observed outside the critical radius. Relativistic quenching of the effect is found to occur for hole masses M>8*10^7 solar masses. The numerical results combined with the observed properties of galactic nuclei indicate that for most galaxies the resonant enhancement to tidal disruption rates will be very small.

Kevin P. Rauch; Brian Ingalls

1997-10-24T23:59:59.000Z

320

A delta configured auxiliary resonant snubber inverter  

SciTech Connect

A delta ({Delta}) configured auxiliary resonant snubber inverter is developed to overcome the voltage floating problem in a wye (Y) configured resonant snubber inverter. The proposed inverter is to connect auxiliary resonant branches between phase outputs to avoid a floating point voltage which may cause over-voltage failure of the auxiliary switches. Each auxiliary branch consists of a resonant inductor and a reverse blocking auxiliary switch. Instead of using an anti-paralleled diode to allow resonant current to flow in the reverse direction, as in the Y-configured version, the resonant branch in the {Delta}-configured version must block the negative voltage, typically done by a series diode. This paper shows single-phase and three-phase versions of {Delta}-configured resonant snubber inverters and describes in detail the operating principle of a single-phase version. The extended three-phase version is proposed with non-adjacent state space vector modulation. For hardware implementation, a single-phase 1-kW unit and a three-phase 100-kW unit were built to prove the concept. Experimental results show the superiority of the proposed topology.

Lai, J.S.; Young, R.W.; Ott, G.W. Jr.; McKeever, J.W. [Oak Ridge National Lab., TN (United States). Engineering Technology Div.; Peng, F.Z. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

1995-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Perception of Face Parts and Face Configurations: An fMRI Study  

E-Print Network (OSTI)

fMRI studies have reported three regions in human ventral visual cortex that respond selectively to faces: the occipital face area (OFA), the fusiform face area (FFA), and a face-selective region in the superior temporal ...

Kanwisher, Nancy

322

Manual labeling strategy for ground truth estimation in MRI glial tumor segmentation  

Science Conference Proceedings (OSTI)

In this paper we focused our attention on the problem of determining reliable ground truth for validating unsupervised, fully automatic MRI brain tumor segmentation procedures in the clinical context of Glial Tumor treatment. The goal was achieved by ...

Valentina Pedoia; Alessandro De Benedictis; Giuseppe Renis; Emanuele Monti; Sergio Balbi; Elisabetta Binaghi

2012-05-01T23:59:59.000Z

323

Scattering by coupled resonating elements in air  

E-Print Network (OSTI)

Scattering by (a) a single composite scatterer consisting of a concentric arrangement of an outer N-slit rigid cylinder and an inner cylinder which is either rigid or in the form of a thin elastic shell and (b) by a finite periodic array of these scatterers in air has been investigated analytically and through laboratory experiments. The composite scatterer forms a system of coupled resonators and gives rise to multiple low frequency resonances. The corresponding analytical model employs polar angle dependent boundary conditions on the surface of the N-slit cylinder. The solution inside the slits assumes plane waves. It is shown also that in the low-frequency range the N-slit rigid cylinder can be replaced by an equivalent fluid layer. Further approximations suggest a simple square root dependence of the resonant frequencies on the number of slits and this is confirmed by data. The observed resonant phenomena are associated with Helmholtz-like behaviour of the resonator for which the radius and width of the openings are much smaller than the wavelength. The problem of scattering by a finite periodic array of such coupled resonators in air is solved using multiple scattering techniques. The resulting model predicts band-gap effects resulting from the resonances of the individual composite scatterers below the first Bragg frequency . Predictions and data confirm that use of coupled resonators results in substantial insertion loss peaks related to the resonances within the concentric configuration. In addition, for both scattering problems experimental data, predictions of the analytical approach and predictions of the equivalent fluid layer approximations are compared in the low-frequency interval.

Anton Krynkin; Olga Umnova; Alvin Y. B. Chong; Shahram Taherzadeh; Keith Attenborough

2011-01-12T23:59:59.000Z

324

SPIN COUPLING RESONANCE STUDY IN AGS.  

SciTech Connect

In the AGS spin resonances due to coupling may account for as much as a 50 percent loss in polarization at a reduced acceleration rate. The major source of coupling in the AGS is the solenoidal snake. In the past some preliminary work was done to understand this phenomena, and a method to overcome these resonances was attempted. However in the polarized proton run of 2002 we sought to study more thoroughly the response of these coupled spin resonances to the strength of the solenoidal snake, skew quadrupoles and vertical and horizontal betatron tune separation. In this paper we present our results and compare them with those predicted by a modified DEPOL program.

RANJBAR,V.; AHRENS,L.; BAI,M.; BROWN,K.; GLENN,W.; HUANG,H.; LUCCIO,A.; MACKAY,W.W.; PTITSYN,V.; ROSER,T.; TSOUPAS,N.; LEE,S.Y.

2002-06-02T23:59:59.000Z

325

Parametric Resonance of Optically Trapped Aerosols  

E-Print Network (OSTI)

The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a Lorentzian shape typical of over-damped systems (beads in liquid solvents), to a damped harmonic oscillator spectrum showing a resonance peak. In this later under-damped regime, we excite parametric resonance by periodically modulating the trapping power at twice the resonant frequency. The power spectra of position fluctuations are in excellent agreement with the obtained analytical solutions of a parametrically modulated Langevin equation.

R. Di Leonardo; G. Ruocco; J. Leach; M. J. Padgett; A. J. Wright; J. M. Girkin; D. R. Burnham; D. McGloin

2007-02-23T23:59:59.000Z

326

Split image optical display  

DOE Patents (OSTI)

A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

Veligdan, James T. (Manorville, NY)

2007-05-29T23:59:59.000Z

327

Cyclotron Resonances in Electron Cloud Dynamics  

Science Conference Proceedings (OSTI)

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where lbstripes" found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The existence of the resonances has been confirmed in experiments at PEP-II. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations and experimental observations, the reason for the bunch-length dependence, and details of the dynamics are discussed here.

Celata, C. M.; Furman, Miguel A.; Vay, J.-L.; Ng, J. S.T.; Grote, D. P.; Pivi, M. T. F.; Wang, L. F.

2009-04-29T23:59:59.000Z

328

Plutonium less mysterious with nuclear magnetic resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Plutonium less mysterious with nuclear magnetic resonance Plutonium less mysterious with nuclear magnetic resonance Plutonium less mysterious with nuclear magnetic resonance For more than 50 years, chemists and physicists have been searching for the plutonium-239 magnetic resonance signal. May 21, 2012 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

329

Very-High-Frequency Resonant Boost Converters  

E-Print Network (OSTI)

This paper presents a resonant boost topology suitable for very-high-frequency (VHF, 30-300 MHz) DC-DC power conversion. The proposed design features low device voltage stress, high efficiency over a wide load range, and ...

Perreault, David J.

330

Photoproduction of hyperon resonances on hydrogen  

DOE Green Energy (OSTI)

We present the current status of our work on the extraction of cross sections and polarizations for photoproduction of hyperon resonances on a hydrogen target (pK+Y*) using existing data from the CEBAF Large Acceptance Spectrometer (CLAS). The cross sections and polarizations will be used for a simultaneous theoretical analysis of hyperon ground state and hyperon resonance production. Thus far we have identified the hyperon resonances 0(1385), (1405), and (1520) through missing mass and invariant mass cuts in various decay channels, such as 0, +-, 00, +-, -+, pK- and nK0. We have not yet seen the resonances (1600), (1660), (1670), (1670) and (1690), although they need to be included for the analysis of the hyperon ground state production.

Henry Juengst

2001-08-01T23:59:59.000Z

331

Power transfer through strongly coupled resonances  

E-Print Network (OSTI)

Using self-resonant coils in a strongly coupled regime, we experimentally demonstrate efficient non-radiative power transfer over distances of up to eight times the radius of the coils. We use this system to transfer 60W ...

Kurs, André

2007-01-01T23:59:59.000Z

332

Resonant Planetary Waves in a Spherical Atmosphere  

Science Conference Proceedings (OSTI)

A global model of planetary wave propagation in a spherical atmosphere is used to examine the spectrum of free or resonant planetary waves of the solstitial stratosphere. These free modes are located by forcing the model with a weak periodic ...

Mark R. Schoeberl; John H. E. Clark

1980-01-01T23:59:59.000Z

333

Nuclear Resonance Fluorescence for Nuclear Materials Assay.  

E-Print Network (OSTI)

??This dissertation examines the measurement of nuclear resonance fluorescence gamma-rays as a technique to non-destructively determine isotopic compositions of target materials that are of interest… (more)

Quiter, Brian Joseph

2010-01-01T23:59:59.000Z

334

Industrial applications of photonuclear resonance excitation  

E-Print Network (OSTI)

Photonuclear resonance excitation refers to a variety of photonuclear interaction processes that lead to the excitation of a nucleus from some initial state to a higher energy nuclear state. Typical excited nuclear state ...

Chichester, David Lee, 1971-

2000-01-01T23:59:59.000Z

335

Resonant-cavity antenna for plasma heating  

DOE Patents (OSTI)

This invention relates generally to a method and apparatus for transferring energy to a plasma immersed in a magnetic field, and relates particularly to an apparatus for heating a plasma of low atomic number ions to high temperatures by transfer of energy to plasma resonances, particularly the fundamental and harmonics of the ion cyclotron frequency of the plasma ions. This invention transfers energy from an oscillating radio-frequency field to a plasma resonance of a plasma immersed in a magnetic field.

Perkins, F.W. Jr.; Chiu, S.C.; Parks, P.; Rawls, J.M.

1984-01-10T23:59:59.000Z

336

Resonant-cavity antenna for plasma heating  

SciTech Connect

Disclosed is a resonant coil cavity wave launcher for energizing a plasma immersed in a magnetic field. Energization includes launching fast Alfven waves to excite ion cyclotron frequency resonances in the plasma. The cavity includes inductive and capacitive reactive members spaced no further than one-quarter wavelength from a first wall confinement chamber of the plasma. The cavity wave launcher is energized by connection to a waveguide or transmission line carrying forward power from a remote radio frequency energy source.

Perkins, Jr., Francis W. (Princeton, NJ); Chiu, Shiu-Chu (San Diego, CA); Parks, Paul (San Diego, CA); Rawls, John M. (Del Mar, CA)

1987-01-01T23:59:59.000Z

337

Nonlinear Fano resonance and bistable wave transmission  

E-Print Network (OSTI)

We consider a discrete model that describes a linear chain of particles coupled to a single-site defect with instantaneous Kerr nonlinearity. We show that this model can be regarded as a nonlinear generalization of the familiar Fano-Anderson model, and it can generate the amplitude depended bistable resonant transmission or reflection. We identify these effects as the nonlinear Fano resonance, and study its properties for continuous waves and pulses.

Andrey E. Miroshnichenko; Sergei F. Mingaleev; Sergej Flach; Yuri S. Kivshar

2004-12-14T23:59:59.000Z

338

Green Function in the Resonance Region  

E-Print Network (OSTI)

We analyse the three-point function of vector, axial-vector and pseudoscalar currents. In the spirit of large N_C, a resonance dominated Green function is confronted with the leading high-energy behaviour from the operator product expansion. The matching is shown to be fully compatible with a chiral resonance Lagrangian and it allows to determine some of the chiral low-energy constants of O(p^6).

V. Cirigliano; G. Ecker; M. Eidemuller; A. Pich; J. Portoles

2004-04-01T23:59:59.000Z

339

Simulation of ion cyclotron resonance heating through resonant absorption in two-ion species plasma  

DOE Green Energy (OSTI)

Particle simulation of two-ion hybrid cyclotron resonance heating (ICRH) of a magnetized hydrogen plasma with deuteron minority by magnetosonic waves launched from the low magnetic field side is reported. Depending on the minority concentration, partial transmission and partial reflection of the incoming waves off the two-ion hybrid resonance layer occur, in contrast to the mode conversion mainly taking place during incidence from the high field side. Preferential minority heating is observed, as the minority cyclotron resonance is close to the two-ion hybrid resonance layer.

Tajima, T.; Riyopoulos, S.; Demchenko, V.

1987-01-01T23:59:59.000Z

340

Cyclotron Resonances in Electron Cloud Dynamics  

SciTech Connect

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where l{sub b} << 2{pi}{omega}{sub c}, (l{sub b} = bunch duration, {omega}{sub c} = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor {approx} 3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined density 'stripes' of multipactoring found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations, the reason for the bunch-length dependence, and details of the dynamics will be discussed.

Celata, C M; Furman, M A; Vay, J L; Grote, D P; Ng, J T; Pivi, M F; Wang, L F

2009-05-05T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Phase I ResonantSonic CRADA report  

Science Conference Proceedings (OSTI)

This test report describes the Phase 1 testing and results of the ResonantSonic drilling method. This effort was conducted as part of a Cooperative Research and Development Agreement (CRADA) between the US Department of Energy, Pacific Northwest Laboratory, Westinghouse Hanford Company and Water Development Corporation. The purpose of this demonstration was to evaluate the Water Development Corporation`s ResonantSonic drilling system, modify components as necessary and determine compatible drilling applications for the ResonantSonic drilling method for use at facilities in the DOE complex and private industry. Initially, the ResonantSonic drill was used to drill several test holes at the Drilling Technology Test Site to assess the feasibility of drilling vertical and angle holes. After this initial phase, a 45 degree angle vapor extraction well was drilled to a depth of 168 feet at the 200 West Carbon Tetrachloride Site. This well was drilled and completed in nine days. Extensive geologic and vapor sampling were conducted while drilling this well. In addition, testing was also conducted at the test site to evaluated drilling with larger diameter casing (8 5/8 inch). Evaluation of the Resonant Sonic drilling method will be continued during the Phase 2 portion of testing to determine if improvements to the ResonantSonic system will make it a more viable method for drilling and sampling.

Richterich, L.R.; Amos, L.O.; Fancher, J.D.; McLellan, G.W.; Setzer, W.V.; Tuttle, B.G. [Westinghouse Hanford Co., Richland, WA (United States); Hockey, R.L.; Ferris, R.H.; Riechers, D.M.; Pitman, S.G. [Pacific Northwest Lab., Richland, WA (United States)

1994-03-28T23:59:59.000Z

342

Multicolor Underwater Imaging Techniques.  

E-Print Network (OSTI)

??Studies were conducted on multispectral polarimetric subtraction imaging techniques for underwater imaging that use a broadband light source. The main objective of this study was… (more)

Waggoner, Douglas Scott

2007-01-01T23:59:59.000Z

343

Magnetic resonance studies on ZnO nanocrystals  

Science Conference Proceedings (OSTI)

ZnO nanocrystals with diameters ranging from 4 to 50 nm were prepared via a wet chemical method and post-growth annealing treatments. The electron paramagnetic resonance (EPR) spectra of the nanocrystals show the resonance of electron centers with g-value ... Keywords: K ? P theory, ZnO nanocrystal, electronic paramagnetic resonance (EPR), magnetic resonance

H. Zhou; A. Hofstaetter; D. M. Hofmann; B. K. Meyer

2003-05-01T23:59:59.000Z

344

A survey of shaped-based registration and segmentation techniques for cardiac images  

Science Conference Proceedings (OSTI)

Heart disease is the leading cause of death in the modern world. Cardiac imaging is routinely applied for assessment and diagnosis of cardiac diseases. Computerized image analysis methods are now widely applied to cardiac segmentation and registration ... Keywords: AAM, ASM, CT, CVD, Cardiac CT, Cardiac MR, Cardiac motion, Cardiac registration, Cardiac segmentation, EB, EDV, EF, EFFD, EM, ESV, Echocardiography, Endo, Epi, FE, FFD, Four CH, GMM, GRPM, LA, LADA, LAX, LCX, LV, MI, MIA, MRF, MRI, N, N/A, NMI, NURBS, P, PCA, PET, PM, RA, RPM, RV, Review article, SAD, SAX, SM, SPECT, SSD, TDI, TEE, TMI, US

Vahid Tavakoli, Amir A. Amini

2013-09-01T23:59:59.000Z

345

Deactivation of Sensory-Specific Cortex by Cross-Modal Stimuli  

Science Conference Proceedings (OSTI)

Visual and auditory cortices traditionally have been considered to be "modality-specific." Thus, their activity has been thought to be unchanged by information in other sensory modalities. However, using functional magnetic resonance imaging (fMRI), ...

Paul J. Laurienti; Jonathan H. Burdette; Mark T. Wallace; Yi-Fen Yen; Aaron S. Field; Barry E. Stein

2002-04-01T23:59:59.000Z

346

Stanford Synchrotron Radiation Lightsource  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Line 10-2 in parallel with magnetic resonance imaging (MRI) at Wayne State University to map and quantify iron and calcium on the same slices of human brain, thus...

347

Mining partially annotated images  

Science Conference Proceedings (OSTI)

In this paper, we study the problem of mining partially annotated images. We first define what the problem of mining partially annotated images is, and argue that in many real-world applications annotated images are typically partially annotated and ... Keywords: image annotation completion and prediction, partially annotated training set, semi-supervised learning

Zhongang Qi; Ming Yang; Zhongfei (Mark) Zhang; Zhengyou Zhang

2011-08-01T23:59:59.000Z

348

Seismic Imaging and Monitoring  

SciTech Connect

I give an overview of LANL's capability in seismic imaging and monitoring. I present some seismic imaging and monitoring results, including imaging of complex structures, subsalt imaging of Gulf of Mexico, fault/fracture zone imaging for geothermal exploration at the Jemez pueblo, time-lapse imaging of a walkway vertical seismic profiling data for monitoring CO{sub 2} inject at SACROC, and microseismic event locations for monitoring CO{sub 2} injection at Aneth. These examples demonstrate LANL's high-resolution and high-fidelity seismic imaging and monitoring capabilities.

Huang, Lianjie [Los Alamos National Laboratory

2012-07-09T23:59:59.000Z

349

Seismic Imaging and Monitoring  

SciTech Connect

I give an overview of LANL's capability in seismic imaging and monitoring. I present some seismic imaging and monitoring results, including imaging of complex structures, subsalt imaging of Gulf of Mexico, fault/fracture zone imaging for geothermal exploration at the Jemez pueblo, time-lapse imaging of a walkway vertical seismic profiling data for monitoring CO{sub 2} inject at SACROC, and microseismic event locations for monitoring CO{sub 2} injection at Aneth. These examples demonstrate LANL's high-resolution and high-fidelity seismic imaging and monitoring capabilities.

Huang, Lianjie [Los Alamos National Laboratory

2012-07-09T23:59:59.000Z

350

Web accessible image similarity measurements  

Science Conference Proceedings (OSTI)

Web accessible image similarity measurements. Background: There ... messages). Web Access to Image Similarity Measurements. ...

2013-04-16T23:59:59.000Z

351

Manhattan Project: Trinity Images  

Office of Scientific and Technical Information (OSTI)

IMAGES IMAGES Trinity Test Site (July 16, 1945) Resources > Photo Gallery The first 0.11 seconds of the Nuclear Age These seven photographs of the Trinity test were taken by time-lapse cameras. The last is 109 milliseconds, or 0.109 seconds, after detonation. Scroll down to view each individual image. The photographs are courtesy the Los Alamos National Laboratory, via the Federation of American Scientists web site. The animation is original to the Office of History and Heritage Resources. The dawn of the Nuclear Age (Trinity image #1) The dawn of the Nuclear Age Trinity image #2 Trinity image #3 Trinity image #4 Trinity image #5 Trinity, 0.09 seconds after detonation (Trinity image #6) Trinity, 0.09 seconds after detonation Trinity, 0.11 seconds after detonation (Trinity image #7)

352

Cyclotron Resonances in Electron Cloud Dynamics  

Science Conference Proceedings (OSTI)

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where l{sub b} stripes' of multipactoring found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations, the reason for the bunch-length dependence, and details of the dynamics will be discussed.

Celata, C M; Furman, M A; Vay, J L; Grote, D P; Ng, J T; Pivi, M F; Wang, L F

2009-05-05T23:59:59.000Z

353

Gas lasers with wave-chaotic resonators  

E-Print Network (OSTI)

Semiclassical multimode laser theory is extended to gas lasers with open two-dimensional resonators of arbitrary shape. The Doppler frequency shift of the linear-gain coefficient leads to an additional linear coupling between the modes, which, however, is shown to be negligible. The nonlinear laser equations simplify in the special case of wave-chaotic resonators. In the single-mode regime, the intensity of a chaotic laser, as a function of the mode frequency, displays a local minimum at the frequency of the atomic transition. The width of the minimum scales with the inhomogeneous linewidth, in contrast to the Lamb dip in uniaxial resonators whose width is given by the homogeneous linewidth.

Oleg Zaitsev

2010-10-28T23:59:59.000Z

354

Nonlinear Resonances in the Solar System  

E-Print Network (OSTI)

Orbital resonances are ubiquitous in the Solar system. They play a decisive role in the long term dynamics, and in some cases the physical evolution, of the planets and of their natural satellites, as well as the evolution of small bodies (including dust) in the planetary system. The few-body gravitational problem of hierarchical planetary-type systems allows for a complex range of dynamical timescales, from the fast orbital periods to the very slow orbit precession rates. The interaction of fast and slow degrees of freedom produces a rich diversity of resonance phenomena. Weak dissipative effects --- such as tides or radiation drag forces --- also produce unexpectedly rich dynamical behaviors. This paper provides a mostly qualitative discussion of simple dynamical models for the commonly encountered orbital resonance phenomena in the Solar system.

Renu Malhotra

1994-06-13T23:59:59.000Z

355

Renormalized Resonance Quartets in Dispersive Wave Turbulence  

Science Conference Proceedings (OSTI)

Using the (1+1)D Majda-McLaughlin-Tabak model as an example, we present an extension of the wave turbulence (WT) theory to systems with strong nonlinearities. We demonstrate that nonlinear wave interactions renormalize the dynamics, leading to (i) a possible destruction of scaling structures in the bare wave systems and a drastic deformation of the resonant manifold even at weak nonlinearities, and (ii) creation of nonlinear resonance quartets in wave systems for which there would be no resonances as predicted by the linear dispersion relation. Finally, we derive an effective WT kinetic equation and show that our prediction of the renormalized Rayleigh-Jeans distribution is in excellent agreement with the simulation of the full wave system in equilibrium.

Lee, Wonjung [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012 (United States); Kovacic, Gregor [Mathematical Sciences Department, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States); Cai, David [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012 (United States); Mathematics Department, Shanghai Jiao Tong University, Shanghai 200240 (China)

2009-07-10T23:59:59.000Z

356

Image registration method for medical image sequences  

DOE Patents (OSTI)

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

Gee, Timothy F.; Goddard, James S.

2013-03-26T23:59:59.000Z

357

Structure of Resonance in Preheating after Inflation  

E-Print Network (OSTI)

We consider preheating in the theory $1/4 \\lambda \\phi^4 + 1/2 g^2\\phi^2\\chi^2 $, where the classical oscillating inflaton field $\\phi$ decays into $\\chi$-particles and $\\phi$-particles. The parametric resonance which leads to particle production in this conformally invariant theory is described by the Lame equation. It significantly differs from the resonance in the theory with a quadratic potential. The structure of the resonance depends in a rather nontrivial way on the parameter $g^2/\\lambda$. We construct the stability/instability chart in this theory for arbitrary $g^2/\\lambda$. We give simple analytic solutions describing the resonance in the limiting cases $g^2/\\lambda\\ll 1$ and $g^2/\\lambda \\gg 1$, and in the theory with $g^2=3\\lambda$, and with $g^2 =\\lambda$. From the point of view of parametric resonance for $\\chi$, the theories with $g^2=3\\lambda$ and with $g^2 =\\lambda$ have the same structure, respectively, as the theory $1/4 \\lambda \\phi^4$, and the theory $\\lambda /(4 N) (\\phi^2_i)^2$ of an N-component scalar field $\\phi_i$ in the limit $N \\to \\infty$. We show that in some of the conformally invariant theories such as the simplest model $1/4 \\lambda\\phi^4$, the resonance can be terminated by the backreaction of produced particles long before $$ or $phi^2 >$ become of the order $\\phi^2$. We analyze the changes in the theory of reheating in this model which appear if the inflaton field has a small mass.

Patrick Greene; Lev Kofman; Andrei Linde; Alexei Starobinsky

1997-05-19T23:59:59.000Z

358

Meson Production and Baryon Resonances at CLAS  

Science Conference Proceedings (OSTI)

I give a brief overview of the exploration of baryon properties in meson photo- and electroproduction. These processes provide ample information for the study of electromagnetic couplings of baryon resonances and to search for states, yet to be discovered. The CLAS detector, combined with the use of energy-tagged polarized photons and polarized electrons, as well as polarized targets and the measurement of recoil polarization, provide the tools for a comprehensive nucleon resonance program. I briefly present the status of this program, prospects for the next few years, and plans for the Jefferson Lab 12 GeV upgrade.

Volker Burkert

2011-02-01T23:59:59.000Z

359

Meson Production and Baryon Resonances at CLAS  

E-Print Network (OSTI)

I give a brief overview of the exploration of baryon properties in meson photo- and electroproduction. These processes provide ample information for the study of electromagnetic couplings of baryon resonances and to search for states, yet to be discovered. The CLAS detector, combined with the use of energy-tagged polarized photons and polarized electrons, as well as polarized targets and the measurement of recoil polarization, provide the tools for a comprehensive nucleon resonance program. I briefly present the status of this program, prospects for the next few years, and plans for the Jefferson Lab 12 GeV upgrade.

Volker D. Burkert

2010-08-17T23:59:59.000Z

360

Kicked rotor quantum resonances in position space  

E-Print Network (OSTI)

We present an approach of the kicked rotor quantum resonances in position-space, based on its analogy with the optical Talbot effect. This approach leads to a very simple picture of the physical mechanism underlying the dynamics and to analytical expressions for relevant physical quantities, such as mean momentum or kinetic energy. The ballistic behavior, which is closely associated to quantum resonances, is analyzed and shown to emerge from a coherent adding of successive kicks applied to the rotor thanks to a periodic reconstruction of the spatial wavepacket.

Maxence Lepers; Véronique Zehnlé; Jean Claude Garreau

2007-11-11T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Kicked rotor quantum resonances in position space  

E-Print Network (OSTI)

We present an approach of the kicked rotor quantum resonances in position-space, based on its analogy with the optical Talbot effect. This approach leads to a very simple picture of the physical mechanism underlying the dynamics and to analytical expressions for relevant physical quantities, such as mean momentum or kinetic energy. The ballistic behavior, which is closely associated to quantum resonances, is analyzed and shown to emerge from a coherent adding of successive kicks applied to the rotor thanks to a periodic reconstruction of the spatial wavepacket.

Lepers, Maxence; Garreau, Jean Claude

2007-01-01T23:59:59.000Z

362

String resonances at the Large Hadron Collider  

E-Print Network (OSTI)

The Large Hadron Collider promises to discover new physics beyond the Standard Model. An exciting possibility is the formation of string resonances at the TeV scale. In this article, we show how string resonances may be detected at the LHC in the $pp\\to\\gamma+jet$ channel. Our study is based on event shape variables, missing energy and momentum, maximum transverse momentum of photons and dijet invariant mass. These observables provide interesting signatures which enable us to discriminate string events from the Standard Model background.

Arunava Roy; Marco Cavaglia

2009-02-09T23:59:59.000Z

363

Holography and Anomaly Matching for Resonances  

E-Print Network (OSTI)

We derive a universal relation for the transverse part of triangle anomalies within a class of theories whose gravity dual is described by the Yang-Mills-Chern-Simons theory. This relation provides a set of sum rules involving the masses, decay constants and couplings between resonances, and leads to the formulas for the matrix elements of the vector and axial currents in the presence of the soft electromagnetic field. We also discuss that this relation is valid in real QCD at least approximately. This may be regarded as the anomaly matching for resonances as an analogue of that for the massless excitations in QCD.

Dam T. Son; Naoki Yamamoto

2010-10-04T23:59:59.000Z

364

Analyzing the level of presence while navigating in a virtual environment during an fMRI scan  

Science Conference Proceedings (OSTI)

We have conducted an fMRI research using virtual reality to study the level of presence that subjects experience during the navigation through a virtual environment, in comparison with the presence felt during a video or a photograph viewing task. The ... Keywords: SUS questionnaire, fMRI, navigation, presence, virtual reality

Miriam Clemente; Alejandro Rodríguez; Beatriz Rey; Aina Rodríguez; Rosa M. Baños; Cristina Botella; Mariano Alcañiz; César Ávila

2011-09-01T23:59:59.000Z

365

Ultralow Superharmonic Resonance for Functional Nanowires  

E-Print Network (OSTI)

a second harmonic mode at 6.20. In the classical case the nanowire does not enter resonance below frequencies.9 However, the search for ultralow reso- nance frequencies was largely discontinued because terms in both sin(t) and sin(2t) as has been discussed elsewhere.10 Above this frequency, the second

366

Giant resonance study by 6li scattering  

E-Print Network (OSTI)

Nuclear incompressibility Knm is an important parameter in the nuclear matter equation of state (EOS). The locations of the isocalar giant monopole resonance (ISGMR) and giant dipole resonance (ISGDR) of nuclei are directly related to Knm and thus can give the most effective constraint on the value of the Knm. In order to determine Knm accurately, a systematic study of the ISGMR and ISGDR over a wide range of nuclei is necessary. Alpha inelastic scattering at small angles has been successfully used to study the ISGMR of heavy and medium nuclei where the monopole resonance is concentrated in a broad peak. For light nuclei (Aradioactive nuclei with inverse reactions using 6Li as a target. Data for elastic scattering of 240 MeV 6Li ions and inelastic scattering to low-lying states and giant resonances was taken for 24Mg, 28Si and 116Sn. A data analysis procedure was developed for double folding calculations. The optical potential parameters for 6Li + 24Mg, 6Li + 28Si and 6Li + 116Sn scattering systems were obtained by fitting elastic scattering data. Multipole analyses were carried out for inelastic scattering to high lying isoscalar giant resonances with multipolarities L=0 - 3. The results for the ISGMR and ISGQR are in agreement with those obtained with 240 MeV ? scattering, however the agreement for the ISGDR and HEOR is not so good, indicating the uncertainty in extracting these strengths. This work has shown that 240 MeV 6Li scattering is a viable way to study the ISGMR and ISGQR and can be particularly useful in rare isotope studies where 6Li can be used as the target.

Chen, Xinfeng

2008-05-01T23:59:59.000Z

367

Optimization of a microwave resonator cavity to perform electron spin resonance measurements on quantum dots  

E-Print Network (OSTI)

This thesis attempts to improve on an ongoing experiment of detecting electron spin resonance (ESR) on AlGaAs/GaAs lateral quantum dots. The experiment is performed in a 2.5 Tesla magnetic field at temperatures around ...

Burger, Anat

2006-01-01T23:59:59.000Z

368

Estimation theoretical image restoration  

E-Print Network (OSTI)

In this thesis, we have developed an extensive study to evaluate image restoration from a single image, colored or monochromatic. Using a mixture of Gaussian and Poisson noise process, we derived an objective function to ...

Dolne, Jean J

2008-01-01T23:59:59.000Z

369

Spectrographic imaging system  

DOE Patents (OSTI)

An imaging system for providing spectrographically resolved images. The system incorporates a one-dimensional spatial encoding mask which enables an image to be projected onto a two-dimensional image detector after spectral dispersion of the image. The dimension of the image which is lost due to spectral dispersion on the two-dimensional detector is recovered through employing a reverse transform based on presenting a multiplicity of different spatial encoding patterns to the image. The system is especially adapted for detecting Raman scattering of monochromatic light transmitted through or reflected from physical samples. Preferably, spatial encoding is achieved through the use of Hadamard mask which selectively transmits or blocks portions of the image from the sample being evaluated.

Morris, Michael D. (Ann Arbor, MI); Treado, Patrick J. (Ann Arbor, MI)

1991-01-01T23:59:59.000Z

370

Synthetic stereoscopic panoramic images  

Science Conference Proceedings (OSTI)

Presented here is a discussion of the techniques required to create stereoscopic panoramic images. Such images allow interactive exploration of 3D environments with stereoscopic depth cues. If projected in a surround display environment they can engage ...

Paul Bourke

2006-10-01T23:59:59.000Z

371

Nuclear Imaging instrumentation  

NLE Websites -- All DOE Office Websites (Extended Search)

Nuclear Imaging instrumentation Advances in gamma-ray detection and imaging have increased the pace of discovery in a broad cross-section of the sciences ranging from nuclear...

372

Helical rays in two-dimensional resonant wave conversion  

E-Print Network (OSTI)

2] D.G. Swanson, Theory of Mode Conversion and Tunneling inin two-dimensional resonant wave conversion Allan N. KaufmanThe process of resonant wave conversion (often called linear

Kaufman, Allan N.; Tracy, Eugene R.; Brizard, Alain J.

2004-01-01T23:59:59.000Z

373

Resonating group method study of baryon-meson systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Resonating group method study of baryon-meson systems in a chiral quark model F. Huang Institute of High Energy Physics, Chinese Academy of Sciences Using the resonating group...

374

A Hollow-Ion Resonance of Unprecedented Strength  

NLE Websites -- All DOE Office Websites (Extended Search)

A Hollow-Ion Resonance of Unprecedented Strength A Hollow-Ion Resonance of Unprecedented Strength Print Wednesday, 29 June 2005 00:00 A so-called hollow ion is formed when core...

375

Document Imaging | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Document Imaging Document Imaging Employee Services Cafeterias Conferencing and Special Events Copy Services Document Imaging Exchange Visitors Program Facility Operations Food...

376

Quantum Theory of Transmission Line Resonator-Assisted Cooling of a Micromechanical Resonator  

E-Print Network (OSTI)

We propose a quantum description of the cooling of a micromechanical flexural oscillator by a one-dimensional transmission line resonator via a force that resembles cavity radiation pressure. The mechanical oscillator is capacitively coupled to the central conductor of the transmission line resonator. At the optimal point, the micromechanical oscillator can be cooled near to the ground state and the cooling can be measured by homodyne detection of the output microwave signal.

Li, Yong; Xue, Fei; Bruder, C

2008-01-01T23:59:59.000Z

377

Quantum Theory of Transmission Line Resonator-Assisted Cooling of a Micromechanical Resonator  

E-Print Network (OSTI)

We propose a quantum description of the cooling of a micromechanical flexural oscillator by a one-dimensional transmission line resonator via a force that resembles cavity radiation pressure. The mechanical oscillator is capacitively coupled to the central conductor of the transmission line resonator. At the optimal point, the micromechanical oscillator can be cooled close to the ground state, and the cooling can be measured by homodyne detection of the output microwave signal.

Yong Li; Ying-Dan Wang; Fei Xue; C. Bruder

2008-04-30T23:59:59.000Z

378

NIST Image Gallery: Search  

Science Conference Proceedings (OSTI)

... Search Tips - Search index includes image titles, descriptions, other text fields - Searches are case-insensitive - Keyword2 is optional. ...

379

Cell Image Visualization  

Science Conference Proceedings (OSTI)

... Biological cell image analysis projects include methods to measure cell segmentation accuracy and new segmentation methods to track live cells. ...

2011-06-17T23:59:59.000Z

380

Video image position determination  

DOE Patents (OSTI)

An optical beam position controller in which a video camera captures an image of the beam in its video frames, and conveys those images to a processing board which calculates the centroid coordinates for the image. The image coordinates are used by motor controllers and stepper motors to position the beam in a predetermined alignment. In one embodiment, system noise, used in conjunction with Bernoulli trials, yields higher resolution centroid coordinates.

Christensen, Wynn (Los Alamos, NM); Anderson, Forrest L. (Bernalillo, NM); Kortegaard, Birchard L. (Los Alamos, NM)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Imaging with Scattered Neutrons  

E-Print Network (OSTI)

We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.

H. Ballhausen; H. Abele; R. Gaehler; M. Trapp; A. Van Overberghe

2006-10-30T23:59:59.000Z

382

Spin-isospin resonances with relativistic RPA approaches  

SciTech Connect

The relativistic RPA approaches are applied to calculate the charge-exchange spin flip resonances. Comparing the RPA calculations based on the relativistic Hartree and relativistic Hartree-Fock theories, the different physical mechanisms in determining the Gamow-Teller resonance are investigated. Then, the theoretical descriptions of spin-dipole and spin-quadrupole resonances are presented. In particular, the energy hierarchies of different components in these resonances are focused on.

Meng Jie [School of Physics and Nuclear Energy, Beihang University, Beijing 100191 (China); State Key Lab Nucl. Phys. and Tech., School of Physics, Peking University, Beijing 100871 (China); Liang Haozhao [State Key Lab Nucl. Phys. and Tech., School of Physics, Peking University, Beijing 100871 (China); Institut de Physique Nucleaire, IN2P3-CNRS and Universite Paris-Sud, 91406 Orsay (France); Nguyen Van Giai [Institut de Physique Nucleaire, IN2P3-CNRS and Universite Paris-Sud, 91406 Orsay (France)

2010-05-12T23:59:59.000Z

383

Acoustic Imaging Suite  

INL’s acoustic imaging technology improves methods of capturing moving images of a specified object by using a photorefractive effect to produce a full-field image of the object without using a probe to perform a full scan of the object. INL ...

384

Medical imaging systems  

Science Conference Proceedings (OSTI)

A medical imaging system provides simultaneous rendering of visible light and diagnostic or functional images. The system may be portable, and may include adapters for connecting various light sources and cameras in open surgical environments or laparascopic or endoscopic environments. A user interface provides control over the functionality of the integrated imaging system. In one embodiment, the system provides a tool for surgical pathology.

Frangioni, John V

2013-06-25T23:59:59.000Z

385

Diagnostic Imaging Emergency Medicine  

E-Print Network (OSTI)

UC Davis Veterinary Diagnostic Imaging Symposium Emergency Medicine May 15, 2011 Gladys Valley Hall devoted to triage, assessment, and imaging diagnostics in emergency medicine. Speakers in this year's symposium include specialists in diagnostic imaging, and emergency and critical care. Sunday May 15, 2011 8

Hammock, Bruce D.

386

An Analysis of Algorithms for In Vivo Fiber Tractography Using DW-MRI Data  

E-Print Network (OSTI)

An Analysis of Algorithms for In Vivo Fiber Tractography Using DW-MRI Data 780 Project Jing Li. The relationship of the diffusion weighted (DW) pixel intensity , the tensor T and DW gradient vector is described pixel intensity with the DW gradients are set to zero; is the unit vector describing the DW gradient

Goodman, James R.

387

Predicting clinical variable from MRI features: application to MMSE in MCI  

Science Conference Proceedings (OSTI)

The ability to predict a clinical variable from automated analysis of single, cross-sectional T1-weighted (T1w) MR scans stands to improve the management of patients with neurological diseases. We present a methodology for predicting yearly Mini-Mental ... Keywords: MRI, deformation, intensity, mild cognitive impairment, mini-mental score examination, multiple regression, principal components analysis

S. Duchesne; A. Caroli; C. Geroldi; G. B. Frisoni; D. Louis Collins

2005-10-01T23:59:59.000Z

388

A new approach for the validation of skeletal muscle modelling using MRI data  

Science Conference Proceedings (OSTI)

Active and passive experiments on skeletal muscles are in general arranged on isolated muscles or by consideration of the whole muscle packages, such as the arm or the leg. Both methods exhibit advantages and disadvantages. By applying ... Keywords: Biceps brachii muscle, Finite element method, MRI data, Micromechanical modelling, Optical experiments, Transversal isotropy

Markus Böl; Maike Sturmat; Christine Weichert; Cornelia Kober

2011-05-01T23:59:59.000Z

389

A Methodology to Validate MRI/SPECT Registration Methods Using Realistic Simulated SPECT Data  

Science Conference Proceedings (OSTI)

We present a method to validate MRI/SPECT registration methods based on a set of computer-generated SPECT data. The data set was produced through Monte Carlo simulations from an attenuation map and an activity map derived from a manually labeled T1-weighted ...

Christophe Grova; Arnaud Biraben; Jean-Marie Scarabin; Pierre Jannin; Irène Buvat; Habib Benali; Bernard Gibaud

2001-10-01T23:59:59.000Z

390

MAPPING OUT THE FULL SPIN RESONANCE STRUCTURE OF RHIC.  

SciTech Connect

We extended the ability of DEPOL [1] to calculate coupled spin resonances and used it to determine the location and strength of both intrinsic and coupled spin resonances in RHIC. In particular we are interested in the full resonance structure with solenoidal elements turned on and with quadrupole rolls[2].

RANJBAR,V.; LEE,S.Y.; MACKAY,W.W.; BAI,M.; COURANT,E.

2001-06-18T23:59:59.000Z

391

Performance of monolayer graphene nanomechanical resonators with electrical readout  

E-Print Network (OSTI)

, including high-sensitivity mass detectors, is put in place. S ince its discovery in 2004 (ref. 1), graphene long). The graphene resonances, visible as parabola-shaped features, are highly tunable with gate voltage for both devices. In b, besides graphene resonances (I), resonances from the metal clamps

Heinz, Tony F.

392

NUCLEAR RESONANT SCATTERING AT HIGH PRESSURE AND HIGH TEMPERATURE  

E-Print Network (OSTI)

NUCLEAR RESONANT SCATTERING AT HIGH PRESSURE AND HIGH TEMPERATURE JIYONG ZHAOa,Ã? , WOLFGANG, The University of Chicago, Chicago, IL 60637, USA We introduce the combination of nuclear resonant inelastic X the thermal radiation spectra fitted to the Planck radiation function up to 1700 K. Nuclear resonant

Shen, Guoyin

393

Nuclear Magnetic Resonance: Portable and integrated Lead: P. Poulichet.  

E-Print Network (OSTI)

Nuclear Magnetic Resonance: Portable and integrated Lead: P. Poulichet. Permanent members: L. Rousseau, A. Fakri. Associated researchers: C. Delabie, A. Exertier. Portable Nuclear Magnetic Resonance : our work in the field of nuclear magneto resonance is focused on the design and the realization

Baudoin, Geneviève

394

ENVIRONMENT AND SUSTAINABLE DEVELOPMENT  

E-Print Network (OSTI)

-5968 Email: stroscio@uic.edu Website: nanotechcenter.uic.edu Center for Medical Simulation Pat Banerjee HYDROCEPHALUS Live patient MRI Computer Simulation · Data from Magnetic Resonance Imaging. · Use of MRI And New Applications Such Targeted Drug Delivery · Brownian Dynamics Simulations For Spherical And Slender

Nesterov, Yurii

395

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson*  

E-Print Network (OSTI)

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson summarize recent developments of nuclear resonant spectroscopy methods like nuclear resonant inelastic x important information on valence, spin state, and magnetic ordering. Both methods use a nuclear resonant

Jackson, Jennifer M.

396

Shape-based image retrieval applied to trademark images  

Science Conference Proceedings (OSTI)

In this chapter, we propose a new shape-based, query-by-example, image database retrieval method that is able to match a query image to one of the images in the database, based on a whole or partial match. The proposed method has two key components: ... Keywords: image databases, shape analysis, shape representation, shape-based image retrieval, trademark image retrieval

Ossama El Badawy; Mohamed Kamel

2004-01-01T23:59:59.000Z

397

OpenEI Community - images  

Open Energy Info (EERE)

Image upload with broken thumbnail image http:en.openei.orgcommunitydiscussionimage-upload-broken-thumbnail-image

OpenEI users can upload images to the wiki by typing a new...

398

Similarity Retrieval of Trademark Images  

Science Conference Proceedings (OSTI)

The Artisan system retrieves abstract trademark images by shape similarity. It analyzes each image to characterize key shape components, grouping image regions into families that potentially mirror human image perception, and then derives characteristic ...

John P. Eakins; Jago M. Boardman; Margaret E. Graham

1998-04-01T23:59:59.000Z

399

SNAP Image Gallery  

NLE Websites -- All DOE Office Websites (Extended Search)

Images Images Cutaway image of SNAP A cutaway illustration of SNAP showing some of the interior optics. Cutaway image of SNAP A computer generated cutaway illustration of SNAP Cutaway image of SNAP's primary mirror A computer generated cutaway illustration of SNAP's primary mirror image of SNAP spacecraft A computer generated illustration of the SNAP spacecraft computer generated image of SNAP A computer generated illustration of SNAP Before-and-after pictures (and Hubble Space Telescope picture) of a high-redshift supernovae discovered by the Supernova Cosmology Project in March, 1998. Before-and-after pictures (and Hubble Space Telescope picture) of a high-redshift supernovae discovered in March, 1998. This observaton showed that the expansion of the universe was accelerarting. Credit: High Redshift Supernova Search Supernova Cosmology Project

400

Resonant spectroscopy of the antihydrogen atom  

SciTech Connect

The spectra of the hydrogen and antihydrogen atoms in the presence of an external electric field are compared. It is shown that the nonresonant corrections to the transition frequency may contain terms linear in the electric field. The existence of these terms does not violate space and time parity and leads to a difference in the resonant spectroscopic measurements for the hydrogen and antihydrogen atoms in an external electric field.

Labzowsky, Leonti [St. Petersburg State University, 198504 Petrodvorets, St. Petersburg, Russia (Russian Federation); Petersburg Nuclear Physics Institute, 188350 Gatchina, St. Petersburg, Russia (Russian Federation); Solovyev, Dmitri [St. Petersburg State University, 198504 Petrodvorets, St. Petersburg, Russia (Russian Federation)

2003-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Resonance tunneling spectroscopy of heteropoly compounds  

SciTech Connect

The electron tunneling spectra of phosphomolybdic and phosphomolybdovanadic acids have been measured using a scanning tunneling microscope. A new mechanism of negative differential resistance (NDR) formation in tunneling nanocontacts is established, which is general for all systems featuring the Wannier-Stark localization effect. A two-center inelastic resonance tunneling model is constructed, which allows the values of both electron and vibrational energy parameters to be determined from the measured spectra.

Dalidchik, F. I., E-mail: domfdal@mail.ru; Budanov, B. A.; Kolchenko, N. N.; Balashov, E. M.; Kovalevskii, S. A. [Russian Academy of Sciences, Semenov Institute of Chemical Physics (Russian Federation)

2012-12-15T23:59:59.000Z

402

Resonant radiation shed by dispersive shock waves  

E-Print Network (OSTI)

We show that dispersive shock waves resulting from the nonlinearity overbalancing a weak leading-order dispersion can emit resonant radiation owing to higher-order dispersive contributions. We analyze such phenomenon for the defocusing nonlinear Schroedinger equation, giving criteria for calculating the radiated frequency based on the estimate of the shock velocity, revealing also a diversity of possible scenarios depending on the order and magnitude of the dispersive corrections.

Conforti, Matteo; Trillo, Stefano

2013-01-01T23:59:59.000Z

403

Study of spin resonances in the accelerators with snakes  

Science Conference Proceedings (OSTI)

Spin resonances in the circular accelerators with snakes are studied to understand the nature of snake resonances. We analyze the effect of snake configuration, and the snake superperiod on the resonance. Defining the critical resonance strength epsilon/sub c/ as the maximum tolerable resonance strength without losing the beam polarization after passing through the resonance, we found that epsilon/sub c/ is a sensitive function of the snake configuration, the snake superperiod at the first order snake resonance, the higher order snake resonance conditions and the spin matching condition. Under properly designed snake configuration, the critical resonance strength epsilon/sub c/ is found to vary linearly with N/sub S/ as = (1/..pi..)sin/sup /minus/1/(/vert bar/cos ..pi nu../sub z//vert bar//sup /1/2//)N/sub S/, where ..nu../sub z/ and N/sub S/ are the betatron tune and the number of snakes respectively. We also study the effect of overlapping intrinsic and imperfection resonances. The imperfection resonance should be corrected to a magnitude of insignificance (e.g., epsilonless than or equal to0.1 for two snakes case) to maintain proper polarization. 23 refs., 25 figs.

Lee, S.Y.

1988-01-01T23:59:59.000Z

404

Study of spin resonances in the accelerators with snakes  

SciTech Connect

Spin resonances in the circular accelerators with snakes are studied to understand the nature of snake resonances. We analyze the effect of snake configuration, and the snake superperiod on the resonance. Defining the critical resonance strength epsilon/sub c/ as the maximum tolerable resonance strength without losing the beam polarization after passing through the resonance, we found that epsilon/sub c/ is a sensitive function of the snake configuration, the snake superperiod at the first order snake resonance, the higher order snake resonance conditions and the spin matching condition. Under properly designed snake configuration, the critical resonance strength epsilon/sub c/ is found to vary linearly with N/sub S/ as = (1/..pi..)sin/sup /minus/1/(/vert bar/cos ..pi nu../sub z//vert bar//sup /1/2//)N/sub S/, where ..nu../sub z/ and N/sub S/ are the betatron tune and the number of snakes respectively. We also study the effect of overlapping intrinsic and imperfection resonances. The imperfection resonance should be corrected to a magnitude of insignificance (e.g., epsilonless than or equal to0.1 for two snakes case) to maintain proper polarization. 23 refs., 25 figs.

Lee, S.Y.

1988-01-01T23:59:59.000Z

405

Time Resolved Shadowgraph Images of Silicon during Laser Ablation:Shockwaves and Particle Generation  

SciTech Connect

Time resolved shadowgraph images were recorded of shockwaves and particle ejection from silicon during laser ablation. Particle ejection and expansion were correlated to an internal shockwave resonating between the shockwave front and the target surface. The number of particles ablated increased with laser energy and was related to the crater volume.

Liu, C.Y.; Mao, X.L.; Greif, R.; Russo, R.E.

2006-05-06T23:59:59.000Z

406

An Efficient Algorithm for Mapping Imaging Data to 3D Unstructured Grids in Computational Biomechanics  

Science Conference Proceedings (OSTI)

Geometries for organ scale and multiscale simulations of organ function are now routinely derived from imaging data. However, medical images may also contain spatially heterogeneous information other than geometry that are relevant to such simulations either as initial conditions or in the form of model parameters. In this manuscript, we present an algorithm for the efficient and robust mapping of such data to imaging based unstructured polyhedral grids in parallel. We then illustrate the application of our mapping algorithm to three different mapping problems: 1) the mapping of MRI diffusion tensor data to an unstuctured ventricular grid; 2) the mapping of serial cyro-section histology data to an unstructured mouse brain grid; and 3) the mapping of CT-derived volumetric strain data to an unstructured multiscale lung grid. Execution times and parallel performance are reported for each case.

Einstein, Daniel R.; Kuprat, Andrew P.; Jiao, Xiangmin; Carson, James P.; Einstein, David M.; Corley, Richard A.; Jacob, Rick E.

2013-01-01T23:59:59.000Z

407

An Approach for Preoperative Planning and Performance of MR-guided Interventions Demonstrated With a Manual Manipulator in a 1.5T MRI Scanner  

Science Conference Proceedings (OSTI)

Purpose: The aim of this work was to develop and test a general methodology for the planning and performance of robot-assisted, MR-guided interventions. This methodology also includes the employment of software tools with appropriately tailored routines to effectively exploit the capabilities of MRI and address the relevant spatial limitations. Methods: The described methodology consists of: (1) patient-customized feasibility study that focuses on the geometric limitations imposed by the gantry, the robotic hardware, and interventional tools, as well as the patient; (2) stereotactic preoperative planning for initial positioning of the manipulator and alignment of its end-effector with a selected target; and (3) real-time, intraoperative tool tracking and monitoring of the actual intervention execution. Testing was performed inside a standard 1.5T MRI scanner in which the MR-compatible manipulator is deployed to provide the required access. Results: A volunteer imaging study demonstrates the application of the feasibility stage. A phantom study on needle targeting is also presented, demonstrating the applicability and effectiveness of the proposed preoperative and intraoperative stages of the methodology. For this purpose, a manually actuated, MR-compatible robotic manipulation system was used to accurately acquire a prescribed target through alternative approaching paths. Conclusions: The methodology presented and experimentally examined allows the effective performance of MR-guided interventions. It is suitable for, but not restricted to, needle-targeting applications assisted by a robotic manipulation system, which can be deployed inside a cylindrical scanner to provide the required access to the patient facilitating real-time guidance and monitoring.

Seimenis, Ioannis [Medical Diagnostic Center 'Ayios Therissos' (Cyprus); Tsekos, Nikolaos V. [University of Huston, Medical Robotics Lab, Department of Computer Science (United States); Keroglou, Christoforos [University of Cyprus, Department of Electrical and Computer Engineering (Cyprus); Eracleous, Eleni [Medical Diagnostic Center 'Ayios Therissos' (Cyprus); Pitris, Constantinos [University of Cyprus, Department of Electrical and Computer Engineering (Cyprus); Christoforou, Eftychios G., E-mail: e.christoforou@ucy.ac.cy [University of Cyprus, KIOS Research Center (Cyprus)

2012-04-15T23:59:59.000Z

408

Real-Time Imaging of Two-Dimensional Cardiac Strain Using a Harmonic Phase Magnetic Resonance Imaging  

E-Print Network (OSTI)

myocardial func- tion during stress tests with free breathing. It was previously shown that standard tag-tracking

Atalar, Ergin

409

ARM - Measurement - Hydrometeor image  

NLE Websites -- All DOE Office Websites (Extended Search)

image image ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor image Images of hydrometeors from which one can derive characteristics such as size and shape. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments LEARJET : Lear Jet PARTIMG : Particle imager UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments SPEC-CPI : Stratton Park Engineering Company - Cloud particle imager UAV-PROTEUS : UAV Proteus

410

Video image position determination  

DOE Patents (OSTI)

The present invention generally relates to the control of video and optical information and, more specifically, to control systems utilizing video images to provide control. Accurate control of video images and laser beams is becoming increasingly important as the use of lasers for machine, medical and experimental processes escalates. In, AURORA, an installation at Los Alamos National Laboratory dedicated to laser fusion research, it is necessary to precisely control the path and angle of up to 96 lasers beams. This invention is comprised of an optical beam position controller in which a video camera captures an image of the beam in its video frames, and conveys those images to a processing board which calculates the centroid coordinates for the image. The image coordinates are used by motor controllers and stepper motors to position the beam in a predetermined alignment. In one embodiment, system noise, used in conjunction with Bernoulli trials, yields higher resolution centroid coordinates.

Christensen, W.; Anderson, F.L.; Kortegaard, B.L.

1990-01-01T23:59:59.000Z

411

Video image position determination  

DOE Patents (OSTI)

The present invention generally relates to the control of video and optical information and, more specifically, to control systems utilizing video images to provide control. Accurate control of video images and laser beams is becoming increasingly important as the use of lasers for machine, medical and experimental processes escalates. In, AURORA, an installation at Los Alamos National Laboratory dedicated to laser fusion research, it is necessary to precisely control the path and angle of up to 96 lasers beams. This invention is comprised of an optical beam position controller in which a video camera captures an image of the beam in its video frames, and conveys those images to a processing board which calculates the centroid coordinates for the image. The image coordinates are used by motor controllers and stepper motors to position the beam in a predetermined alignment. In one embodiment, system noise, used in conjunction with Bernoulli trials, yields higher resolution centroid coordinates.

Christensen, W.; Anderson, F.L.; Kortegaard, B.L.

1990-12-31T23:59:59.000Z

412

Ferroelectric optical image comparator  

DOE Patents (OSTI)

A ferroelectric optical image comparator has a lead lanthanum zirconate titanate thin-film device which is constructed with a semi-transparent or transparent conductive first electrode on one side of the thin film, a conductive metal second electrode on the other side of the thin film, and the second electrode is in contact with a nonconducting substrate. A photoinduced current in the device represents the dot product between a stored image and an image projected onto the first electrode. One-dimensional autocorrelations are performed by measuring this current while displacing the projected image. 7 figures.

Butler, M.A.; Land, C.E.; Martin, S.J.; Pfeifer, K.B.

1993-11-30T23:59:59.000Z

413

Ferroelectric optical image comparator  

DOE Patents (OSTI)

A ferroelectric optical image comparator has a lead lanthanum zirconate titanate thin-film device which is constructed with a semi-transparent or transparent conductive first electrode on one side of the thin film, a conductive metal second electrode on the other side of the thin film, and the second electrode is in contact with a nonconducting substrate. A photoinduced current in the device represents the dot product between a stored image and an image projected onto the first electrode. One-dimensional autocorrelations are performed by measuring this current while displacing the projected image.

Butler, Michael A. (Albuquerque, NM); Land, Cecil E. (Albuquerque, NM); Martin, Stephen J. (Albuquerque, NM); Pfeifer, Kent B. (Los Lunas, NM)

1993-01-01T23:59:59.000Z

414

Image Shift Measurement  

Science Conference Proceedings (OSTI)

... Set the write directory to a new folder for the cropped images. Use Process Folder / Text file / Template to make the boiler plate processing file. ...

415

Manhattan Project: Places Images  

Office of Scientific and Technical Information (OSTI)

PLACES IMAGES PLACES IMAGES Resources > Photo Gallery Scroll down to see each of these images individually. The images are: 1. Remains of a Shinto Shrine, Nagasaki, October 1945 (courtesy the United States Marine Corps, Lieutenant R. J. Battersby, photographer, via the National Archives); 2. University of California, Berkeley, 1940 (courtesy the Lawrence Berkeley National Laboratory); 3. Aerial photograph of the Trinity Site after the test (courtesy the Federation of American Scientists); 4. Aerial photograph of Hiroshima before the bombing; 5. Columbia University, 1903 (courtesy the Library of Congress; this photograph originated from the Detroit Publishing Company; it was a 1949 gift to the Library of Congress from the State Historical Society of Colorado).

416

Quantitative luminescence imaging system  

DOE Patents (OSTI)

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopic imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber. 22 figs.

Erwin, D.N.; Kiel, J.L.; Batishko, C.R.; Stahl, K.A.

1990-08-14T23:59:59.000Z

417

Imaging Beyond Optics  

NLE Websites -- All DOE Office Websites (Extended Search)

Views" piece in that same issue. "Generations of astronomers have used interferometric tests to achieve the proper shape of their mirrors before using them to image the heavens....

418

Quantitative luminescence imaging system  

DOE Patents (OSTI)

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopie imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber.

Erwin, David N. (San Antonio, TX); Kiel, Johnathan L. (San Antonio, TX); Batishko, Charles R. (West Richland, WA); Stahl, Kurt A. (Richland, WA)

1990-01-01T23:59:59.000Z

419

Kursk Site Image #1  

NLE Websites -- All DOE Office Websites (Extended Search)

Graphs Image KRS-1: Clipping above-ground biomass at the Kursk grassland site, Russia. (Dr. Kira Khodashova and student Nina N., Moscow State University, are estimating monthly...

420

Detection power, temporal response, and spatial resolution of IRON fMRI in awake, behaving monkeys at 3 Tesla  

E-Print Network (OSTI)

The main goal of this thesis was to systematically characterize the detection sensitivity, temporal response, and spatial resolution of IRON contrast for fMRI within the awake, behaving monkey. Understanding these issues ...

Leite, Francisca Maria Pais Horta

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

The cortical organization of audio-visual sentence comprehension: an fMRI study at 4 Tesla  

E-Print Network (OSTI)

The cortical organization of audio-visual sentence comprehension: an fMRI study at 4 Tesla Cheryl M Tesla. Participants viewed the face and upper body of a speaker via a video screen while listening

422

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources  

SciTech Connect

Microwave injection methods for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant "volume" ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources.

Alton, Gerald D. (Kingston, TN)

1998-01-01T23:59:59.000Z

423

BNL | Dardo Tomasi  

NLE Websites -- All DOE Office Websites (Extended Search)

Dardo Tomasi Dardo Tomasi Research Interests Along the years my work has shifted from nuclear and astroparticle physics to MRI gradient coil design, functional MRI and PET imaging. I developed the Phase Reference Method, an MRI technique to map the magnetic fields with high spatial and temporal resolutions that allows to optimize the design of MRI magnets as well as radio frequency and gradient coils which is also valuable for MRI quality control purposes, and the Fast Simultaneous Annealing Method, a novel gradient coil design technique that allows the development of ultra-short gradient coils for faster MRI protocols. I studied the resonant modes of vibration and was able to minimize significantly the sound pressure levels emitted by of our 4T Varian/Siemens MRI scanner, reducing subject's discomfort during fMRI.

424

Automatic Image Orientation Determination with Natural Image Statistics  

E-Print Network (OSTI)

Automatic Image Orientation Determination with Natural Image Statistics Siwei Lyu Dept. of Computer a new method for automatically determining image orientations. This method is based on a set of natural image statistics collected from a multi- scale multi-orientation image decomposition (e.g., wavelets

Lyu, Siwei

425

Quantum Imaging: Enhanced Image Formation Using Quantum States of Light  

E-Print Network (OSTI)

Quantum Imaging: Enhanced Image Formation Using Quantum States of Light Robert W. Boyd, Kam Wai, University of Rochester, Rochester, NY 14627, USA ABSTRACT We review recent research in the field of quantum imaging. Quantum imaging deals with the formation of images that possess higher resolution or better

Boyd, Robert W.

426

Respiratory motion of the heart: Implications for magnetic resonance coronary angiography  

Science Conference Proceedings (OSTI)

Magnetic resonance(MR) coronary imaging is susceptible to artifacts caused by motion of the heart. The purpose of this thesis was to study the respiratory motion of the coronary arteries and to use the results to develop strategies for improved MRimaging. The first section of the thesis describes a MR motion correction technique for objects undergoing a 3D affine transformation. The remainder of the thesis focuses on measuring the respiratory motion of the heart from free breathing x-ray angiograms. Stereo reconstruction methods are used to generate 3D models of the arteries from biplane angiograms. A method for tracking the motion of the arteries in a sequence of biplane images is presented next. The algorithm uses 3D regularizing constraints on the length changes of the arteries and on the spatial regularity of their motion. The algorithm was validated using a deforming vascular phantom. RMS 3D distance errors were measured between centerline models tracked in the x-ray images and gold-standard models derived from a gated 3D MR acquisition. The mean error was 0.69±0.06? mm for four different orientations of the x-ray system. The motion field recovered from free breathing angiograms is a combination of the cardiac contraction and respiratory motion of the heart. A cardiac respiratory parametric model is formulated to decompose the field into independent cardiac and respiratory components. Results are presented for ten patients imaged during spontaneous tidal breathing. For all patients

Guy Shechter

2004-01-01T23:59:59.000Z

427

Charged pion electroproduction above the resonance region  

E-Print Network (OSTI)

[Background] Above the nucleon resonance region, the $N(e,e'\\pi^\\pm)N'$ data cannot be explained by conventional hadronic models. For example, the observed magnitude of the transverse cross section is significantly underestimated in a framework with Reggeized background amplitudes. [Purpose] Develop a phenomenological framework for the $N(e,e'\\pi^\\pm)N'$ reaction at high invariant mass $W$ and deep photon virtuality $Q^2$. [Method] Building on the work of Kaskulov and Mosel, a gauged pion-exchange current is introduced with a running cutoff energy for the proton electromagnetic transition form factor. A new transition form factor is proposed. It respects the correct on-shell limit, has a simple physical interpretation and reduces the number of free parameters by one. [Results] A study of the $W$ dependence of the $N(e,e'\\pi^\\pm)N'$ lends support for the newly proposed transition form factor. In addition, an improved description of the separated and unseparated cross sections at $-t \\lesssim 0.5 \\;\\text{GeV}^2$ is obtained. The predictions overshoot the measured unseparated cross sections for $-t > 0.5 \\;\\text{GeV}^2$. Introducing a strong hadronic form factor in the Reggeized background amplitudes brings the calculations considerably closer to the high $-t$ data. [Conclusions] Hadronic models corrected for resonance/parton duality describe the separated pion electroproduction cross sections above the resonance region reasonably well at low $-t$. In order to validate the applicability of these models at high $-t$, separated cross sections are needed. These are expected to provide a more profound insight into the relevant reaction mechanisms.

Tom Vrancx; Jan Ryckebusch

2013-10-29T23:59:59.000Z

428

Imaging techniques applied to the study of fluids in porous media  

Science Conference Proceedings (OSTI)

Improved imaging techniques were used to study the dynamics of fluid flow and trapping at various scales in porous media. Two-phase and three-phase floods were performed and monitored by computed tomography (CT) scanning and/or nuclear magnetic resonance imaging (NMRI) microscopy. Permeability-porosity correlations obtained from image analysis were combined with porosity distributions from CT scanning to generate spatial permeability distributions within the core which were used in simulations of two-phase floods. Simulation-derived saturation distributions of two-phase processes showed very good agreement with the CT measured values.

Tomutsa, L.; Doughty, D.; Brinkmeyer, A.; Mahmood, S.

1992-06-01T23:59:59.000Z

429

A dynamical mechanism for establishing apsidal resonance  

E-Print Network (OSTI)

We show that in a system of two planets initially in nearly circular orbits, an impulse perturbation that imparts a finite eccentricity to one planet's orbit causes the other planet's orbit to become eccentric as well, and also naturally results in a libration of their relative apsidal longitudes for a wide range of initial conditions. We suggest that such a mechanism may explain orbital eccentricities and apsidal resonance in some exo-planetary systems. The eccentricity impulse could be caused by the ejection of a planet from these systems, or by torques from a primordial gas disk. The amplitude of secular variations provides an observational constraint on the dynamical history of such systems.

Renu Malhotra

2002-07-04T23:59:59.000Z

430

Resonant electron-CF collision processes  

SciTech Connect

Electronic structure methods are combined with variationalfixed-nuclei electron scattering calculations and nuclear dynamicsstudies to characterize resonant vibrational excitation and electronattachment processes in collisions between low-energy electrons and CFradicals. Several low-lying negative ion states are found which give riseto strong vibrational excitation and which are expected to dominate thelow-energy electron scattering cross sections. We have also studiedseveral processes which could lead to production of negative ions (F- andC-), However, in contrast to other recent predictions, we do not find CFin itsground state to be a significant source of negative ion productionwhen interacting with thermal electrons.

Trevisan, Cynthia S.; Orel, Ann E.; Rescigno, Thomas N.

2005-03-18T23:59:59.000Z

431

Self-consistent resonance in a plasma  

E-Print Network (OSTI)

As an application of the solution of the equations of electromagnetic self-consistency in a plasma, found in a previous paper, the study of controlled thermo-nuclear fusion is undertaken. This study utilizes the resonance which can be developed in the plasma, as indicated by the above solution, and is based to an analysis of the underlying forced oscillation under friction. As a consequence, we find that, in this way, controlled thermonuclear fusion seems now to be feasible in principle. The treatment is rather elementary, and it may serve as a guide for more detailed calculations.

Evangelos Chaliasos

2005-10-14T23:59:59.000Z

432

Resonantly enhanced four-wave mixing  

DOE Patents (OSTI)

A method and apparatus for achieving large susceptibilities and long interaction lengths in the generation of new wavelengths in the infrared spectral region. A process of resonantly enhanced four-wave mixing is employed, utilizing existing laser sources, such as the CO.sub.2 laser, to irradiate a gaseous media. The gaseous media, comprising NH.sub.3, CH.sub.3 F, D.sub.2, HCl, HF, CO, and H.sub.2 or some combination thereof, are of particular interest since they are capable of providing high repetition rate operation at high flux densities where crystal damage problems become a limitation.

Begley, Richard F. (Los Alamos, NM); Kurnit, Norman A. (Santa Fe, NM)

1978-01-01T23:59:59.000Z

433

Heart imaging method  

DOE Patents (OSTI)

A method for providing an image of the human heart's electrical system derives time-of-flight data from an array of EKG electrodes and this data is transformed into phase information. The phase information, treated as a hologram, is reconstructed to provide an image in one or two dimensions of the electrical system of the functioning heart.

Collins, H. Dale (Richland, WA); Gribble, R. Parks (Richland, WA); Busse, Lawrence J. (Littleton, CO)

1991-01-01T23:59:59.000Z

434

Medical imaging systems  

DOE Patents (OSTI)

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remains in a subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may also employ dyes or other fluorescent substances associated with antibodies, antibody fragments, or ligands that accumulate within a region of diagnostic significance. In one embodiment, the system provides an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide that is used to capture images. In another embodiment, the system is configured for use in open surgical procedures by providing an operating area that is closed to ambient light. More broadly, the systems described herein may be used in imaging applications where a visible light image may be usefully supplemented by an image formed from fluorescent emissions from a fluorescent substance that marks areas of functional interest.

Frangioni, John V. (Wayland, MA)

2012-07-24T23:59:59.000Z

435

DOUBLE MAJORS Imaging Science + ...  

E-Print Network (OSTI)

DOUBLE MAJORS Imaging Science + ... Applied Mathematics Biomedical Sciences Computer Science Undergraduate Research Internships and Cooperative Education (Co-op) (optional) Study Abroad WHY IMAGING SCIENCE Science: BS, MS, PhD Color Science: MS, PhD BS + MS/PhD Combos HUMAN VISION BIO- MEDICAL ASTRO- PHYSICS

Zanibbi, Richard

436

Manhattan Project: Image Retouching`  

Office of Scientific and Technical Information (OSTI)

Image Retouching Image Retouching Resources > Photo Gallery Smyth Report (original) Smyth Report (retouched) Images on this web site have sometimes been "retouched." In every case, however, the intention has been only to restore the image as much as possible to its original condition. Above is a rather extreme example-"before and after" versions of the cover of the Smyth Report (Henry DeWolf Smyth, Atomic Energy for Military Purposes: The Official Report on the Development of the Atomic Bomb under the Auspices of the United States Government, 1940-1945 (Princeton, NJ: Princeton University Press, 1945)). The Smyth Report was commissioned by Leslie Groves and originally issued by the Manhattan Engineer District. Princeton University Press reprinted it in book form as a "public service" with "reproduction in whole or in part authorized and permitted.") Larger versions of the same images are below.

437

GTL Image Gallery  

NLE Websites -- All DOE Office Websites (Extended Search)

Human Genome Project Information • Genomic Science • Microbial Genome Program • sitemap • home Human Genome Project Information • Genomic Science • Microbial Genome Program • sitemap • home Announcing the New Image Gallery Visit the new Image Gallery for an expanded suite of images Biofuels Browse the 2010 "Bioenergy Research Centers: An Overview of the Science" Brochure Gallery. Browse the 2006 "Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda" Report Gallery. Browse more biofuels images (includes the June 2006 "Understanding Biomass" Primer Gallery). Systems Biology Browse the August 2005 "Genomics:GTL Roadmap: Systems Biology for Energy and Environment" Gallery. Basic Genomics Browse the Human Chromosome Gallery. Browse more Basic Genomics images. Carbon Cycling

438

User Science Images  

NLE Websites -- All DOE Office Websites (Extended Search)

User Science Images User Science Images User Science Images Sort by: Default | Name | Date (low-high) | Date (high-low) | Category NIMROD-1.png FES: NIMROD Simulation February 18, 2010 | Author(s): Dr. Charlson C. Kim (University of Washington) | Category: Fusion Energy | URL: https://nimrodteam.org/ Download Image: NIMROD-1.png | png | 1.5 MB Trajectory of an energetic ion in a Field Reverse Configuration (FRC) magnetic field. Magnetic separatrix denoted by green surface. Spheres are colored by azimuthal velocity. Image courtesy of Charlson Kim, University of Washington; NERSC repos m487, mp21, m1552 Scheibe.png BER: Pore-Scale Fluid Flow for Subsurface Reactive Transport January 1, 2008 | Author(s): Timothy D. Scheibe, PNNL | Category: Environmental Science | URL: http://http://subsurface.pnl.gov/

439

Efficient Graffiti Image Retrieval  

Science Conference Proceedings (OSTI)

Research of graffiti character recognition and retrieval, as a branch of traditional optical character recognition (OCR), has started to gain attention in recent years. We have investigated the special challenge of the graffiti image retrieval problem and propose a series of novel techniques to overcome the challenges. The proposed bounding box framework locates the character components in the graffiti images to construct meaningful character strings and conduct image-wise and semantic-wise retrieval on the strings rather than the entire image. Using real world data provided by the law enforcement community to the Pacific Northwest National Laboratory, we show that the proposed framework outperforms the traditional image retrieval framework with better retrieval results and improved computational efficiency.

Yang, Chunlei; Wong, Pak C.; Ribarsky, William; Fan, Jianping

2012-07-05T23:59:59.000Z

440

Edge structure preserving image denoising  

Science Conference Proceedings (OSTI)

Image denoising is important in image analysis. It is often used for pre-processing images so that subsequent image analysis is more reliable. Besides noise removal, one important requirement for image denoising procedures is that they should preserve ... Keywords: Angles, Curvature, Edges, Jump-preserving surface estimation, Local smoothing, Nonparametric regression, Surface estimation

Peihua Qiu; Partha Sarathi Mukherjee

2010-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Adaptive wiener image restoration kernel  

DOE Patents (OSTI)

A method and device for restoration of electro-optical image data using an adaptive Wiener filter begins with constructing imaging system Optical Transfer Function, and the Fourier Transformations of the noise and the image. A spatial representation of the imaged object is restored by spatial convolution of the image using a Wiener restoration kernel.

Yuan, Ding (Henderson, NV)

2007-06-05T23:59:59.000Z

442

Ferrimagnetic Spin Wave Resonance and Superconductivity in Carbon Nanotubes  

E-Print Network (OSTI)

The phenomenon of ferrimagnetic spin wave resonance [uncompensated antiferromagnetic spin wave resonance] has been detected for the first time. It has been observed in carbon nanotubes, produced by high energy ion beam modification of diamond single crystals in $\\ $ direction. Peculiarities of spin wave resonance observed allow to insist on the formation in given nanotubes of $s^+$ superconductivity at room temperature, coexisting with uncompensated antiferromagnetic ordering.

Dmitri Yerchuck; Yauhen Yerchak; Vyacheslav Stelmakh; Alla Dovlatova; Andrey Alexandrov

2013-05-14T23:59:59.000Z

443

Radio-frequency quadrupole resonator for linear accelerator  

DOE Patents (OSTI)

An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.

Moretti, A.

1982-10-19T23:59:59.000Z

444

IMAGING: the Neutron Imaging Prototype Facility at HFIR | ORNL...  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Imaging Prototype Facility CG-1D flight tubes Neutron imaging beam line CG-1D. The CG-1D beam is used for neutron imaging measurements and can be configured for white beam...

445

Biomagnetic Imaging Standards and Microsystems  

Science Conference Proceedings (OSTI)

... Resonance in Medicine (ISMRM), EEEL is developing a standard "phantom" for ... by EEEL and the ISMRM. Committee on Standards for Quantitative. ...

2013-05-13T23:59:59.000Z

446

AGS RESONANT EXTRACTION WITH HIGH INTENSITY BEAMS.  

SciTech Connect

The Brookhaven AGS third integer resonant extraction system allows the AGS to provide high quality, high intensity 25.5 GeV/c proton beams simultaneously to four target stations and as many as 8 experiments. With the increasing intensities (over 7 x 10{sup 13} protons/pulse) and associated longer spill periods (2.4 to 3 seconds long), we continue to run with low losses and high quality low modulation continuous current beams.[1] Learning to extract and transport these higher intensity beams has required a process of careful modeling and experimentation. We have had to learn how to correct for various instabilities and how to better match extraction and the transport lines to the higher emittance beams being accelerated in the AGS. Techniques employed include ''RF'' methods to smooth out momentum distributions and fine structure. We will present results of detailed multi-particle tracking modeling studies which enabled us to develop a clear understanding of beam loss mechanisms in the transport and extraction process. We will report on our status, experiences, and the present understanding of the intensity limitations imposed by resonant extraction and transport to fixed target stations.

AHRENS,L.; BROWN,K.; GLENN,J.W.; ROSER,T.; TSOUPAS,N.; VANASSELT,W.

1999-03-29T23:59:59.000Z

447

Anomalous and resonance small angle scattering  

SciTech Connect

Significant changes in the small angle scattered intensity can be induced by making measurements with radiation close to an absorption edge of an appropriate atomic species contained in the sample. These changes can be related quantitatively to the real and imaginary anomalous dispersion terms for the scattering factor (x-rays) or scattering length (neutrons). The physics inherent in these anomalous dispersion terms is first discussed before considering how they enter the relevant scattering theory. Two major areas of anomalous scattering research have emerged; macromolecules in solution and unmixing of metallic alloys. Research in each area is reviewed, illustrating both the feasibility and potential of these techniques. All the experimental results reported to date have been obtained with x-rays. However, it is pointed out that the formalism is the same or the analogue experiment with neutrons, and a number of suitable isotopes exist which exhibit resonance in an accessible range of energy. Potential applications of resonance small-angle neutron scatterings are discussed. 8 figs.

Epperson, J.E.; Thiyagarajan, P.

1987-11-01T23:59:59.000Z

448

Anomalous and resonance small angle scattering: Revision  

SciTech Connect

Significant changes in the small angle scattered intensity can be induced by making measurements with radiation close to an absorption edge of an appropriate atomic species contained in the sample. These changes can be related quantitatively to the real and imaginary anomalous dispersion terms for the scattering factor (x-rays) or scattering length (neutrons). The physics inherent in these anomalous dispersion terms is first discussed before considering how they enter the relevant scattering theory. Two major areas of anomalous scattering research have emerged; macromolecules in solution and unmixing of metallic alloys. Research in each area is reviewed, illustrating both the feasibility and potential of these techniques. All the experimental results reported to date have been obtained with x-rays. However, it is pointed out that the formalism is the same for the analogue experiment with neutrons, and a number of suitable isotopes exist which exhibit resonance in an accessible range of energy. Potential applications of resonance small angle neutron scatterings are discussed. 54 refs., 8 figs., 1 tab.

Epperson, J.E.; Thiyagarajan, P.

1987-11-01T23:59:59.000Z

449

Resonant tunneling diodes: Models and properties  

E-Print Network (OSTI)

The resonant tunneling diode (RTD) has been widely studied because of its importance in the field of nanoelectronic science and technology and its potential applications in very high speed/functionality devices and circuits. Even though much progress has been made in this regard, additional work is needed to realize the full potential of RTD’s. As research on RTD’s continues, we will try in this tutorial review to provide the reader with an overall and succinct picture of where we stand in this exciting field of research and to address the following questions: What makes RTD’s so attractive? To what extent can RTD’s be modeled for design purposes? What are the required and achievable device properties in terms of digital logic applications? To address these issues, we review the device operational principles, various modeling approaches, and major device properties. Comparisons among the various RTD physical models and major features of RTD’s, resonant interband tunneling diodes, and Esaki tunnel diodes are presented. The tutorial and analysis provided in this paper may help the reader in becoming familiar with current research efforts, as well as to examine the important aspects in further RTD developments and their circuit applications.

Jian Ping Sun; George I. Haddad; Pinaki Mazumder; Joel N. Schulman

1998-01-01T23:59:59.000Z

450

Microwave whispering gallery resonator for efficient optical up-conversion  

E-Print Network (OSTI)

Conversion of microwave radiation into the optical range has been predicted to reach unity quantum efficiency in whispering gallery resonators made from an optically nonlinear crystal and supporting microwave and optical modes simultaneously. In this work we theoretically explore and experimentally demonstrate a resonator geometry that can provide the required phase matching for such a conversion at any desired frequency in the sub-THz range. We show that such a ring-shaped resonator not only allows for the phase matching, but also maximizes the overlap of the interacting fields. As a result, unity-efficient conversion is expected in a resonator with feasible parameters.

D. V. Strekalov; H. G. L. Schwefel; A. A. Savchenkov; A. B. Matsko; L. J. Wang; N. Yu

2009-05-18T23:59:59.000Z

451

Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum ...  

Science Conference Proceedings (OSTI)

Dubal Cell Voltage Drop Initiatives towards Low Energy High Amperage Cells · Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum Electrolysis ...

452

Nonlinear coupling of nano mechanical resonators to Josephson quantum circuits  

E-Print Network (OSTI)

We propose a technique to couple the position operator of a nano mechanical resonator to a SQUID device by modulating its magnetic flux bias. By tuning the magnetic field properly, either linear or quadratic couplings can be realized, with a discretely adjustable coupling strength. This provides a way to realize coherent nonlinear effects in a nano mechanical resonator by coupling it to a Josephson quantum circuit. As an example, we show how squeezing of the nano mechanical resonator state can be realized with this technique. We also propose a simple method to measure the uncertainty in the position of the nano mechanical resonator without quantum state tomography.

Xingxiang Zhou; Ari Mizel

2006-05-01T23:59:59.000Z

453

The Resonance Factor in Einstein's Hidden Variables (Addition)  

Science Conference Proceedings (OSTI)

Planck shifted to black-body radiation in 1900, using purely thermal experimental data (100% entropy, 0% resonance). As a result, when Planck performed his ...

454

The hydrogen bubble chamber and the strange resonances  

SciTech Connect

The author's recollections of his experience in the use of bubble chambers and the discoveries of strange resonances are given. (LEW)

Alvarez, L.W.

1985-06-01T23:59:59.000Z

455

Novel resonance-assisted electromagnetic-transport phenomena  

E-Print Network (OSTI)

We first demonstrate theoretically and experimentally that electromagnetic resonators with high quality factors (Q) can be used to transfer power efficiently over distances substantially larger than the characteristic ...

Kurs, André B

2011-01-01T23:59:59.000Z

456

Resonant energy transfer in light harvesting and light emitting applications.  

E-Print Network (OSTI)

??The performance of light emitting and light harvesting devices is improved by utilising resonant energy transfer. In lighting applications, the emission energy of a semiconductor… (more)

Chanyawadee, Soontorn

2009-01-01T23:59:59.000Z

457

Resonator for Coherent Addition of Semiconductor Laser Arrays ...  

Resonator for Coherent Addition of Semiconductor Laser Arrays and Applications for a Solar Pumped Laser Array Oak Ridge National Laboratory. Contact ...

458

The hydrogen bubble chamber and the strange resonances  

DOE Green Energy (OSTI)

The author's recollections of his experience in the use of bubble chambers and the discoveries of strange resonances are given. (LEW)

Alvarez, L.W.

1985-06-01T23:59:59.000Z

459

Novel nuclear magnetic resonance techniques for studying biological molecules  

E-Print Network (OSTI)

parameters by solid-state nuclear magnetic resonance." J.and R. V. Pound. "Nuclear audiofrequency spectroscopy byresonant heating of the nuclear spin system." Phys. Rev. ,

Laws, David D.

2010-01-01T23:59:59.000Z

460

BREWSTER WINDOW AND WINDOWLESS RESONANT SPECTROPHONES FOR INTRACAVITY OPERATION  

E-Print Network (OSTI)

to 6 KHz measured with windows attached. Variation of thethe spectrophone is operated with windows. Table IV. Factorsto Applied Physics BREWSTER WINDOW AND WINDOWLESS RESONANT

Gerlach, Robert

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Rethinking Feelings: An fMRI Study of the Cognitive Regulation of Emotion  

Science Conference Proceedings (OSTI)

The ability to cognitively regulate emotional responses to aversive events is important for mental and physical health. Little is known, however, about neural bases of the cognitive control of emotion. The present study employed functional magnetic resonance ...

Kevin N. Ochsner; Silvia A. Bunge; James J. Gross; John D. E. Gabrieli

2002-11-01T23:59:59.000Z

462

Image Windows - description of data types  

Science Conference Proceedings (OSTI)

... image, or RGB color image. cstack Stack of color (RGB) images. FRED (text) window; Dialog; (various) graphics windows.

463

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution conductivity imaging  

E-Print Network (OSTI)

to a conductor generates a constant magnetic field with flux density jB r . If the current carrying conductor potentials and the magnetic fields produced by the probing current are measured. Surface potentials and the point spread function is not space invariant. On the other hand, magnetic field and electrical current

Eyüboðlu, Murat

464

Magnetic Resonance Imaging at Princeton, UofV, and UNH | U.S...  

Office of Science (SC) Website

for Teachers and Scientists Small Business Innovation Research and Small Business Technology Transfer Project Assessment Laboratories Ames Laboratory Argonne National...

465

Magnetic resonance imaging of the cerebral metabolic rate of oxygen (CMRO?)  

E-Print Network (OSTI)

Oxygen consumption is an essential process of the functioning brain. The rate at which the brain consumes oxygen is known as the cerebral metabolic rate of oxygen (CMRO?). CMRO? is intimately related to brain health and ...

Bolar, Divya Sanam

2010-01-01T23:59:59.000Z

466

1,2-Hydroxypyridonates as Contrast Agents for Magnetic Resonance Imaging: TREN-1,2-HOPO  

E-Print Network (OSTI)

may be quenched by catechol or ascorbate, or alternately,other bidentate ligands like catechol or maltol do not bind.

2008-01-01T23:59:59.000Z

467

Quantitative diffusion magnetic resonance imaging of the brain : validation, acquisition, and analysis  

E-Print Network (OSTI)

Breton E, Lallemand D, Grenier P, Cabanis E, Laval-JeantetBreton E, Lallemand D, Grenier P, Cabanis E, Laval-JeantetBreton E, Lallemand D, Grenier P, Cabanis E, Laval-Jeantet

White, Nathan S.

2010-01-01T23:59:59.000Z

468

Potential Applications of Microtesla Magnetic Resonance Imaging Detected Using a Superconducting Quantum Interference Device  

E-Print Network (OSTI)

inch thick premium grade A1 oak plywood. Since the 54-inchthe dimensions of 4 by 8 foot plywood sheets, we used ato attach additional plywood to form ~58- inch squares. We

Myers, Whittier R.

2006-01-01T23:59:59.000Z

469

Quantitative Assessment of Myocardial Microstructural Remodeling Using Diffusion Tensor Magnetic Resonance Imaging  

E-Print Network (OSTI)

from periodic cubic b- splines and twenty control pointscontours. The local b-spline tangent direction was used towhite) were derived from b-spline polynomials fitted to

Kung, Geoffrey

2013-01-01T23:59:59.000Z

470

Ghost Imaging with Blackbody Radiation  

E-Print Network (OSTI)

We present a theoretical study of ghost imaging by using blackbody radiation source. A Gaussian thin lens equation for the ghost imaging, which depends on both paths, is derived. The dependences of the visibility and quality of the image on the transverse size and temperature of the blackbody are studied. The main differences between the ghost imaging by using the blackbody radiation and by using the entangled photon pairs are image-forming equation, and the visibility and quality of the image

Yangjian Cai; Shiyao Zhu

2004-07-29T23:59:59.000Z

471

Scanning computed confocal imager  

DOE Patents (OSTI)

There is provided a confocal imager comprising a light source emitting a light, with a light modulator in optical communication with the light source for varying the spatial and temporal pattern of the light. A beam splitter receives the scanned light and direct the scanned light onto a target and pass light reflected from the target to a video capturing device for receiving the reflected light and transferring a digital image of the reflected light to a computer for creating a virtual aperture and outputting the digital image. In a transmissive mode of operation the invention omits the beam splitter means and captures light passed through the target.

George, John S. (Los Alamos, NM)

2000-03-14T23:59:59.000Z

472

Ultraviolet Resonant Raman Enhancements in the Detection of Explosives  

Science Conference Proceedings (OSTI)

Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (non-resonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, however, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided {approx}2000-fold enhancement at 244 nm and {approx}800-fold improvement at 229 nm while PETN showed a maximum of {approx}25-fold at 244 nm and {approx}190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as !4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

Short, B J; Carter, J C; Gunter, D; Hovland, P; Jagode, H; Karavanic, K; Marin, G; Mellor-Crummey, J; Moore, S; Norris, B; Oliker, L; Olschanowsky, C; Roth, P C; Schulz, M; Shende, S; Snavely, A; Spear, W

2009-06-03T23:59:59.000Z

473

Quantitative Imaging in Cell Biology  

E-Print Network (OSTI)

Quantitative! imaging! in! biology! is! concerned! with!Quantitative! imaging! in! biology! is! concerned! with!advances! in! cell! biology! by! enabling! the! tracking!

Yassif, Jaime

2012-01-01T23:59:59.000Z

474

NIST Hyperspectral Image Projector (HIP)  

Science Conference Proceedings (OSTI)

... In DLP systems, the projected image is made from a composite of grayscale images representing each of the RGB colors (red, green, and blue). ...

2013-08-02T23:59:59.000Z

475

NERSC Image and Video Galleries  

NLE Websites -- All DOE Office Websites (Extended Search)

Archive User Science Images Home News & Publications Galleries Galleries 18.jpg NERSC Systems In this gallery view images and videos of the systems that undergird all NERSC...

476

Transversal plasma resonance in a nonmagnetized plasma and possibilities of practical employment of it  

E-Print Network (OSTI)

It is shown that in a nonmagnetized plasma, beside the longitudinal Langmuir resonance, there may also exist the transversal resonance. Both these resonance kinds are degenerated. Employment of the transversal resonance makes it possible to design resonators and filters, as well as powerful single-frequency lasers operating on the basis of collective oscillations of plasma.

F. F. Mende

2005-06-09T23:59:59.000Z

477

Manhattan Project: Science Images  

Office of Scientific and Technical Information (OSTI)

SCIENCE IMAGES SCIENCE IMAGES Resources > Photo Gallery Scroll down to see each of these images individually. The images are: 1. Fission (this graphic is adapted from a graphic originally produced by the Washington State Department of Health; the modifications are original to the History Division, now Office of History and Heritage Resources, 2003); 2. Fat Man (plutonium bomb), August 1945 (courtesy the U.S. Army Corps of Engineers (via theNational Archives)); 3. F Reactor Plutonium Production Complex Hanford, Washington, 1945; 4. A Cockroft-Walton machine at Los Alamos, New Mexico (courtesy the Los Alamos National Laboratory; it is reprinted in John F. Hogerton, ed., "Cockroft-Walton Machine," The Atomic Energy Deskbook (New York: Reinhold Publishing Corporation, 1963, prepared under the auspices of the Division of Technical Information, U.S. Atomic Energy Commission), 102);

478

Ferroelectric optical image comparator  

DOE Patents (OSTI)

The property of ferroelectric ceramics such as lead lanthanum zirconate titanate (PLZT) to store information has been known for many years. This relates to the property of ferroelectric ceramic materials to become permanently polarized when an electric signal is applied to the material. A ferroelectric optical image comparator has a lead lanthanum zirconate titanate thin-film device which is constructed with a semi-transparent or transparent conductive first electrode on one side of the thin film, a conductive metal second electrode on the other side of the thin film, and the second electrode is in contact with a nonconducting substrate. A photoinduced current in the device represents the dot product between a stored image and an image projected onto the first electrode. One-dimensional autocorrelations are performed by measuring this current while displacing the projected image. 5 figs.

Butler, M.A.; Land, C.E.; Martin, S.J.; Pfeifer, K.B.

1989-08-30T23:59:59.000Z

479

Resilient Image Fusion  

Science Conference Proceedings (OSTI)

The paper describes a distributed spectral-screening PCT algorithm for fusing hyper-spectral images in remote sensing applications. The algorithm provides intrusion tolerance from information warfare attacks using the notion of computational resiliency. ...

Tiranee Achalakul; Joohan Lee; Stephen Taylor

2000-08-01T23:59:59.000Z

480

Manhattan Project: People Images  

Office of Scientific and Technical Information (OSTI)

PEOPLE IMAGES PEOPLE IMAGES Resources > Photo Gallery Scroll down to see each of these images individually. The images are: 1. J. Robert Oppenheimer, Enrico Fermi, and Ernest Lawrence (courtesy the Lawrence Berkeley National Laboratory); 2. Hanford, Washington, workers sending money home (reproduced from the photo insert in F. G. Gosling, The Manhattan Project: Making the Atomic Bomb (Washington: History Division, Department of Energy, October 2001)); 3. Oppenheimer and Leslie Groves at the Trinity Site, September 1945 (reproduced from the cover of the Office of History and Heritage Resources publication: The Signature Facilities of the Manhattan Project (Washington: History Division, Department of Energy, 2001)); 4. A WAC detachment marching at Oak Ridge, Tennessee, June 1945 (courtesy the Army Corps of Engineers; it is reprinted in Rachel Fermi and Esther Samra, Picturing the Bomb: Photographs from the Secret World of the Manhattan Project (New York: Harry N. Abrams, Inc., Publishers, 1995), 40);

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