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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.


1

MagLab Audio Dictionary: Magnetic Resonance Imaging (MRI)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetic Resonance Imaging (MRI)? Now Playing: What's Magnetic Resonance Imaging (MRI)? Enable Javascript and Flash to stream the Magnet Minute Sam Grant Associated Links MRI: A...

2

Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold Flooding During Continuous Fuel Cell Operation. Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold...

3

Magnetic resonance imaging (MRI) of solid materials entails numerous problems from short longitudinal relaxation (T2) times to  

E-Print Network [OSTI]

. Solid-State STRAFI NMR Probe for Material Imaging of Quadrupolar Nuclei, J. Magn. Reson. httpMagnetic resonance imaging (MRI) of solid materials entails numerous problems from short for broadband tuning, sample translation along z-axis, and electrodes for in situ battery studies. An Alderman

Weston, Ken

4

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...

Koo, Chiwan

2013-08-09T23:59:59.000Z

5

In vivo imaging with a cell-permeable porphyrin-based MRI contrast agent  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) with molecular probes offers the potential to monitor physiological parameters with comparatively high spatial and temporal resolution in living subjects. For detection of intracellular ...

Lee, Taekwan

6

In Vivo Imaging with a Cell-Permeable Porphyrin-Based MRI Contrast  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) with molecular probes offers the potential to monitor physiological parameters with comparatively high spatial and temporal resolution in living subjects. For detection of intracellular ...

Lee, Taekwan

7

Nuclear magnetic resonance imaging  

Science Journals Connector (OSTI)

Nuclear magnetic resonance imaging (NMRI) is a powerful imaging modality having a range of important applications to medicine and industry. The basic principles of NMRI are reviewed in...

Rothwell, William P

1985-01-01T23:59:59.000Z

8

Designing and characterizing hyperpolarizable silicon nanoparticles for magnetic resonance imaging  

E-Print Network [OSTI]

Magnetic Resonance Imaging (MRI) is one of the most powerful noninvasive tools for diagnosing human disease, but its utility is limited because current contrast agents are ineffective when imaging air-tissue interfaces, ...

Anahtar, Melis Nuray

2008-01-01T23:59:59.000Z

9

An Integrated Method of Adaptive Enhancement for Unsupervised Segmentation of MRI Brain Images  

E-Print Network [OSTI]

An Integrated Method of Adaptive Enhancement for Unsupervised Segmentation of MRI Brain Images of the adaptive enhancement for an unsupervised global-to-local segmentation of brain tissues in three-dimensional (3-D) MRI (Magnetic Resonance Imaging) images. Three brain tissues are of interest: CSF (Cerebro

Pizurica, Aleksandra

10

Tumor Metabolism and Perfusion in Head and Neck Squamous Cell Carcinoma: Pretreatment Multimodality Imaging With {sup 1}H Magnetic Resonance Spectroscopy, Dynamic Contrast-Enhanced MRI, and [{sup 18}F]FDG-PET  

SciTech Connect (OSTI)

Purpose: To correlate proton magnetic resonance spectroscopy ({sup 1}H-MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and {sup 18}F-labeled fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG PET) of nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) for assessment of tumor biology. Additionally, pretreatment multimodality imaging was evaluated for its efficacy in predicting short-term response to treatment. Methods and Materials: Metastatic neck nodes were imaged with {sup 1}H-MRS, DCE-MRI, and [{sup 18}F]FDG PET in 16 patients with newly diagnosed HNSCC, before treatment. Short-term patient radiological response was evaluated at 3 to 4 months. Correlations among {sup 1}H-MRS (choline concentration relative to water [Cho/W]), DCE-MRI (volume transfer constant [K{sup trans}]; volume fraction of the extravascular extracellular space [v{sub e}]; and redistribution rate constant [k{sub ep}]), and [{sup 18}F]FDG PET (standard uptake value [SUV] and total lesion glycolysis [TLG]) were calculated using nonparametric Spearman rank correlation. To predict short-term responses, logistic regression analysis was performed. Results: A significant positive correlation was found between Cho/W and TLG ({rho} = 0.599; p = 0.031). Cho/W correlated negatively with heterogeneity measures of standard deviation std(v{sub e}) ({rho} = -0.691; p = 0.004) and std(k{sub ep}) ({rho} = -0.704; p = 0.003). Maximum SUV (SUVmax) values correlated strongly with MRI tumor volume ({rho} = 0.643; p = 0.007). Logistic regression indicated that std(K{sup trans}) and SUVmean were significant predictors of short-term response (p < 0.07). Conclusion: Pretreatment multimodality imaging using {sup 1}H-MRS, DCE-MRI, and [{sup 18}F]FDG PET is feasible in HNSCC patients with nodal metastases. Additionally, combined DCE-MRI and [{sup 18}F]FDG PET parameters were predictive of short-term response to treatment.

Jansen, Jacobus F.A. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Maastricht University Medical Center, Maastricht (Netherlands); Schoeder, Heiko [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Stambuk, Hilda E. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wang Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Fury, Matthew G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Patel, Senehal G. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Pfister, David G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shah, Jatin P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Koutcher, Jason A. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shukla-Dave, Amita, E-mail: davea@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2012-01-01T23:59:59.000Z

11

Accelerating magnetic resonance imaging by unifying sparse models and multiple receivers  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) is an increasingly versatile diagnostic tool for a variety of medical purposes. During a conventional MRI scan, samples are acquired along a trajectory in the spatial Fourier transform ...

Weller, Daniel (Daniel Stuart)

2012-01-01T23:59:59.000Z

12

Liposome-based mucus-penetrating particles (MPP) for mucosal theranostics: Demonstration of diamagnetic chemical exchange saturation transfer (diaCEST) magnetic resonance imaging (MRI)  

Science Journals Connector (OSTI)

Abstract Mucus barriers lining mucosal epithelia reduce the effectiveness of nanocarrier-based mucosal drug delivery and imaging (“theranostics”). Here, we describe liposome-based mucus-penetrating particles (MPP) capable of loading hydrophilic agents, e.g., the diaCEST MRI contrast agent barbituric acid (BA). We observed that polyethylene glycol (PEG)-coated liposomes containing ? 7 mol% PEG diffused only ~ 10-fold slower in human cervicovaginal mucus (CVM) compared to their theoretical speeds in water. 7 mol%-PEG liposomes contained sufficient BA loading for diaCEST contrast, and provided improved vaginal distribution compared to 0 and 3 mol%-PEG liposomes. However, increasing PEG content to ~ 12 mol% compromised BA loading and vaginal distribution, suggesting that PEG content must be optimized to maintain drug loading and in vivo stability. Non-invasive diaCEST MRI illustrated uniform vaginal coverage and longer retention of BA-loaded 7 mol%-PEG liposomes compared to unencapsulated BA. Liposomal MPP with optimized PEG content hold promise for drug delivery and imaging at mucosal surfaces.

Tao Yu; Kannie W.Y. Chan; Abraham Anonuevo; Xiaolei Song; Benjamin S. Schuster; Sumon Chattopadhyay; Qingguo Xu; Nikita Oskolkov; Himatkumar Patel; Laura M. Ensign; Peter C.M. van Zjil; Michael T. McMahon; Justin Hanes

2014-01-01T23:59:59.000Z

13

K-space reconstruction of magnetic resonance inverse imaging (K-InI) of human visuomotor systems  

E-Print Network [OSTI]

MRI InI Visual MRI Neuroimaging K-InI Inverse solution MEG EEG Electroencephalography channels of a radio-frequency coil array, magnetic resonance inverse imaging (InI) can achieve ultra. Mathematically, the InI reconstruction is a generalization of parallel MRI (pMRI), which includes image space

14

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

15

Integrated magnetic resonance imaging methods for speech science and technology  

Science Journals Connector (OSTI)

This presentation introduces our integration of magnetic resonance imaging(MRI) techniques at ATRBrain Activity Imaging Center (Kyoto Japan) toward research into speech science and technology. The first breakthrough in our application of MRI to speech research was the motion imaging of the speechorgans in articulation using a cardiac cine?MRI method. It enables us to acquire information in the time?space domain to reconstruct successive image frames using utterance repetitions synchronized with MRI scans. This cine?technique was further improved for high?quality imaging and expanded into three?dimensional (3D) visualization of articulatory movements. Using this technique we could successfully obtain temporal changes of vocal?tract area function during a Japanese five?vowel sequence. This effort also contributed to developing other techniques to overcome the limitations of MRI such as the post?hoc inclusion of teeth images in 3D volumes or the phonation?synchronized scan for crystal?sharp static imaging. Further a custom high?sensitivity coil was developed to visualize the fine structures of the lip muscles and laryngeal airway. The potentials of new MRI approaches such as ultra?high?resolution imaging with a higher?field scanner or real?time motion imaging during a single utterance will be discussed toward future contributions to speech science and technology.

Shinobu Masaki; Yukiko Nota; Sayoko Takano; Hironori Takemoto; Tatsuya Kitamura; Kiyoshi Honda

2008-01-01T23:59:59.000Z

16

Spectroscopic imaging from spatially-encoded single-scan multidimensional MRI data  

E-Print Network [OSTI]

Spectroscopic imaging from spatially-encoded single-scan multidimensional MRI data Assaf Tal, Lucio multidimensional magnetic resonance images within a single scan, based on a spatial encoding of the spin in its magnitude the spatial distribution of spins throughout the sample. It is hereby shown that whereas

Frydman, Lucio

17

Artificial Neural Network (ANN) Morphological Classification of Magnetic Resonance Imaging in Multiple Sclerosis  

Science Journals Connector (OSTI)

Multiple Sclerosis (MS) is an autoimmune condition in which the immune system attacks the Central Nervous System. Magnetic Resonance Imaging (MRI) is today a crucial tool for diagnosis of MS by allowing in-vivo d...

Alessia Bramanti; Lilla Bonanno; Placido Bramanti…

2013-01-01T23:59:59.000Z

18

Magnetic resonance spectroscopic imaging with 2D spectroscopy for the detection of brain metabolites  

E-Print Network [OSTI]

While magnetic resonance imaging (MRI) derives its signal from protons in water, additional biochemical compounds are detectable in vivo within the proton spectrum. The detection and mapping of these much weaker signals ...

Kok, Trina

2012-01-01T23:59:59.000Z

19

Magnetic Resonance Imaging in Follow-up Assessment of Sciatica  

Science Journals Connector (OSTI)

...treatment leads to physical and emotional suffering for the patient and substantial costs in terms of treatment, sick leave, and pensions for society. Magnetic resonance imaging (MRI), which is considered the imaging procedure of choice for patients in whom lumbar-disk herniation is suspected,, is frequently... In patients with symptomatic lumbar disk herniation treated with surgery or conservative care, there was no significant association between findings on MRI and clinical outcome at 1 year. Disk herniation persisted in 35% with a favorable outcome and 33% with an unfavorable outcome.

el Barzouhi A.; Vleggeert-Lankamp C.L.A.M.; Lycklama à Nijeholt G.J.

2013-03-14T23:59:59.000Z

20

Fiber-Optic Stethoscope: A Cardiac Monitoring and Gating System for Magnetic Resonance Microscopy  

E-Print Network [OSTI]

during magnetic resonance imaging (MRI) is the distortion of the ECG due to electromagnetic interference

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

Brain MRI Classification using the Expectation Maximization  

E-Print Network [OSTI]

Brain MRI Classification using the Expectation Maximization made a brain magnetic resonance image (MRI) classification algorithm that uses a twostage applied to a set of normal brain MR images for further testing. We accomplished a working

Chen, Tsuhan

22

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

23

Performance Analysis between Two Sparsity Constrained MRI Methods: Highly Constrained Backprojection(HYPR) and Compressed Sensing(CS) for Dynamic Imaging  

E-Print Network [OSTI]

One of the most important challenges in dynamic magnetic resonance imaging (MRI) is to achieve high spatial and temporal resolution when it is limited by system performance. It is desirable to acquire data fast enough to capture the dynamics...

Arzouni, Nibal

2012-10-19T23:59:59.000Z

24

Portable low-cost magnetic resonance imaging  

E-Print Network [OSTI]

Purpose: As the premiere modality for brain imaging, MRI could find wider applicability if lightweight, portable systems were available for siting in unconventional locations such as intensive care units (ICUs), physician ...

Cooley, Clarissa Zimmerman

2014-01-01T23:59:59.000Z

25

Construction of a two-parameter empirical model of left ventricle wall motion using cardiac tagged magnetic resonance imaging data  

E-Print Network [OSTI]

visualized using cardiac tagged magnetic resonance imaging (tMRI) covering the contraction and relaxation phases. Based on the characteristics of the overall dynamics of the LV wall, its motion was represented by a combination of two components - radial...

Shi, Jack J; Alenezy, Mohammed D.; Smirnova, Irina V.; Bilgen, Mehmet

2012-10-24T23:59:59.000Z

26

Magnetic Resonance Imaging in Soil Science  

Science Journals Connector (OSTI)

Magnetic resonance imaging is based upon the physical effect of nuclear magnetic resonance (NMR) of spin bearing atomic...1991; Blümich, 2000...). The most important NMR active nuclei in soil science applications...

Andreas Pohlmeier

2014-08-01T23:59:59.000Z

27

Flow Imaging Using MRI: Quantification and Analysis  

E-Print Network [OSTI]

&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Jim Ji Committee Members, Andrew K. Chan Deepa Kundur Yoonsuck Choe Mary P. McDougall Head of Department, Costas N... Committee: Dr. Jim Ji A complex and challenging problem in flow study is to obtain quantitative flow information in opaque systems, for example, blood flow in biological systems and flow channels in chemical reactors. In this regard, MRI is superior...

Jiraraksopakun, Yuttapong

2010-07-14T23:59:59.000Z

28

MRI and CT image indexing and retrieval using local mesh peak valley edge patterns  

Science Journals Connector (OSTI)

Abstract In this paper, a new pattern based feature, local mesh peak valley edge pattern (LMePVEP) is proposed for biomedical image indexing and retrieval. The standard LBP extracts the gray scale relationship between the center pixel and its surrounding neighbors in an image. Whereas the proposed method extracts the gray scale relationship among the neighbors for a given center pixel in an image. The relations among the neighbors are peak/valley edges which are obtained by performing the first-order derivative. The performance of the proposed method (LMePVEP) is tested by conducting two experiments on two benchmark biomedical databases. Further, it is mentioned that the databases used for experiments are OASIS?MRI database which is the magnetic resonance imaging (MRI) database and VIA/I–ELCAP-CT database which includes region of interest computer tomography (CT) images. The results after being investigated show a significant improvement in terms average retrieval precision (ARP) and average retrieval rate (ARR) as compared to LBP and LBP variant features.

Subrahmanyam Murala; Q.M. Jonathan Wu

2014-01-01T23:59:59.000Z

29

Functional magnetic resonance imaging: imaging techniques and contrast mechanisms  

Science Journals Connector (OSTI)

...Furthermore, in a study of motor recovery, fMRI activation...focal lesion. The future should also see further...able to harness this quantum physics phenomenon...Functional imaging of the motor system. Curr. Opin...assessment with a graded motor activation procedure...past, present, and future. Proc. Natl Acad...

1999-01-01T23:59:59.000Z

30

Quantitative diffusion magnetic resonance imaging of the brain : validation, acquisition, and analysis  

E-Print Network [OSTI]

Engineering, Magnetic Resonance Imaging, Cognitive Science.on magnetic resonance imaging applications in brain science.

White, Nathan S.

2010-01-01T23:59:59.000Z

31

Functional MRI: The Environment and Technology for Clinical Application  

Science Journals Connector (OSTI)

As the applications of functional magnetic resonance imaging (fMRI) in clinical radiology become more evident, several broad requirements must be recognized. First, whereas diagnostic MRI uses visual inspectio...

K. R. Thulborn; B. McCurtain; J. Voyvodic; S. Chang; J. Gillen…

1996-01-01T23:59:59.000Z

32

MRI-guided robot for needle interventions in the prostate.  

E-Print Network [OSTI]

??Magnetic resonance imaging (MRI) is applied to non-invasively visualize patient’s anatomy and tumour suspicious regions with superior soft tissue contrast. Amongst others, online MRI is… (more)

Bosch, M.R. van den

2011-01-01T23:59:59.000Z

33

Challenges for molecular neuroimaging with MRI  

E-Print Network [OSTI]

Magnetic resonance (MRI)-based molecular imaging methods are beginning to have impact in neuroscience. A growing number of molecular imaging agents have been synthesized and tested in vitro, but so far relatively few have ...

Lelyveld, Victor S.

34

Evaluation of Hydatid Disease of the Heart with Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Two patients with cardiac involvement of hydatid disease are presented: one with hydatid cyst of the interventricular septum and pulmonary arteries and the other with multiple pulmonary cysts associated with intracardiac and pericardial cysts. The ability of magnetic resonance imaging (MRI) to provide a global view of cardiac anatomy in any plane with high contrast between flowing blood and soft tissue ensures it an important role in the diagnosis and preoperative assessment of hydatid disease of the heart.

Kotoulas, Grigoris K.; Magoufis, George L.; Gouliamos, Athanasios D.; Athanassopoulou, Alexandra K.; Roussakis, Arcadios C.; Koulocheri, Dimitra P.; Kalovidouris, Angelos; Vlahos, Labros [Department of Radiology, CT-MRI Unit, Areteion Hospital, University of Athens, 76 Vas. Sophias Ave., GR-115 28 Athens (Greece)

1996-05-15T23:59:59.000Z

35

Sub-nanometer resolution in three-dimensional magnetic-resonance imaging of individual dark spins  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) has revolutionized biomedical science by providing non-invasive, three-dimensional biological imaging. However, spatial resolution in conventional MRI systems is limited to tens of microns, which is insufficient for imaging on molecular and atomic scales. Here we demonstrate an MRI technique that provides sub-nanometer spatial resolution in three dimensions, with single electron-spin sensitivity. Our imaging method works under ambient conditions and can measure ubiquitous 'dark' spins, which constitute nearly all spin targets of interest and cannot otherwise be individually detected. In this technique, the magnetic quantum-projection noise of dark spins is measured using a single nitrogen-vacancy (NV) magnetometer located near the surface of a diamond chip. The spatial distribution of spins surrounding the NV magnetometer is imaged with a scanning magnetic-field gradient. To evaluate the performance of the NV-MRI technique, we image the three-dimensional landscape of dark electronic spins at and just below the diamond surface and achieve an unprecedented combination of resolution (0.8 nm laterally and 1.5 nm vertically) and single-spin sensitivity. Our measurements uncover previously unidentified electronic spins on the diamond surface, which can potentially be used as resources for improved magnetic imaging of samples proximal to the NV-diamond sensor. This three-dimensional NV-MRI technique is immediately applicable to diverse systems including imaging spin chains, readout of individual spin-based quantum bits, and determining the precise location of spin labels in biological systems.

M. S. Grinolds; M. Warner; K. De Greve; Y. Dovzhenko; L. Thiel; R. L. Walsworth; S. Hong; P. Maletinsky; A. Yacoby

2014-01-12T23:59:59.000Z

36

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

37

Segmentation of Spin-Echo MRI brain images: a comparison study of Crisp and Fuzzy algorithms  

E-Print Network [OSTI]

This thesis presents a scheme for segmenting Spin-Echo MRI brain images based on Fuzzy C-Mean (FCM) clustering techniques. This scheme consists of feature extraction, feature conditioning or evaluation, and thresholded FCM clustering. Feature...

Chung, Maranatha

2012-06-07T23:59:59.000Z

38

Non-destructive quantification of water gradient in sludge composting with Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Sludge from a slaughter-house wastewater plant, and mixtures of bulking agent (crushed wood pallet) and sludge were studied by Nuclear Magnetic Resonance (NMR). The NMR spin-spin relaxation (T{sub 2}) and spin-lattice relaxation (T{sub 1}) signals for sludge, wet crushed wood pallet and mixtures of sludge and bulking agent were decomposed into three relaxation time components. Each relaxation time component was explained by a non-homogeneous water distribution on a microscopic length scale and by the porosity of the material. For all samples, the T{sub 2} relaxation time value of each component was directly related to the dry matter content. The addition of wet crushed wood to sludge induced a decrease in the relaxation time, explained by water transfer between the sludge and the wood. Magnetic Resonance Imaging (MRI) and respirometric measurements were performed on sludge and wood mixtures. MR images of the mixtures were successfully obtained at different biodegradation states. Based on specific NMR measurements in an identified area located in the MRI cells, the results showed that grey levels of MR images reflected dry matter content. This preliminary study showed that MRI would be a powerful tool to measure water distribution in sludge and bulking agent mixtures and highlights the potential of this technique to increase the understanding of sludge composting.

Duval, F.P.; Quellec, S. [Cemagref, UR TERE, 17 Avenue de Cucille, CS 64427, F-35044 Rennes (France); Universite europeenne de Bretagne (France); Tremier, A.; Druilhe, C. [Cemagref, UR GERE, F-35044 Rennes (France); Universite europeenne de Bretagne (France); Mariette, F., E-mail: francois.mariette@cemagref.f [Cemagref, UR TERE, 17 Avenue de Cucille, CS 64427, F-35044 Rennes (France); Universite europeenne de Bretagne (France)

2010-04-15T23:59:59.000Z

39

Towards the invisible cryogenic system for Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

With about 10 000 Magnetic Resonance Imaging (MRI) systems installed worldwide helium cooled magnets have become familiar equipment in hospitals and imaging centers. Patients and operators are only aware of the hissing sound of the Gifford-MacMahon refrigerator. Service technicians however still work with cryogenic fluids and cold gases e.g. for replenishing the helium reservoir inserting retractable current leads for magnet ramps or replacing burst disks after a magnet quench. We will describe the steps taken at Oxford Magnet Technology towards the ultimate goal of a superconducting magnet being as simple as a household fridge. Early steps included the development of resealing quench valves as well as permanently installed transfer siphons that only open when fully cooled to 4K. On recently launched 1.5 Tesla solenoid magnets 500 A current leads are permanently fixed into the service turret with hardly any boil-off penalty (40–50 cc/hr total). Ramping of the magnet has been fully automated including electronic supervision of the gas-cooled current leads. One step ahead the 1 Tesla High Field Open magnet is refrigerated by a single 4K Gifford MacMahon coldhead relieving the user from the necessity to refill with helium. Our conduction cooled 0.2 Tesla HTS magnet testbed does not require liquid cryogens at any time in its life including initial cool-down.

F. Steinmeyer; P. W. Retz; K. White; A. Lang; W. Stautner; P. N. Smith; G. Gilgrass

2002-01-01T23:59:59.000Z

40

Classification of whole brain fMRI activation patterns  

E-Print Network [OSTI]

Functional magnetic resonance imaging (fMRI) is an imaging technology which is primarily used to perform brain activation studies by measuring neural activity in the brain. It is an interesting question whether patterns ...

Balc?, Serdar Kemal

2008-01-01T23:59:59.000Z

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.


41

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

42

arthritis magnetic resonance: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

during magnetic resonance imaging (MRI) is the distortion of the ECG due to electromagnetic interference cardiac activity that, unlike the ECG, is immune to electromagnetic...

43

Combined fMRI and electrical microstimulation to determine functional connections in visual areas of the primate brain  

E-Print Network [OSTI]

The use of functional magnetic resonance imaging (fMRI) to study the non-human primate brain has been developed over the past decade. Primate fMRI has many attractive features: it allows validation of previous homology ...

Ekstrom, Leeland Bruce

2009-01-01T23:59:59.000Z

44

Magnetic resonance imaging of self-assembled biomaterial scaffolds  

DOE Patents [OSTI]

Compositions and/or mixtures comprising peptide amphiphile compounds comprising one or more contrast agents, as can be used in a range of magnetic resonance imaging applications.

Bull, Steve R; Meade, Thomas J; Stupp, Samuel I

2014-09-16T23:59:59.000Z

45

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

E-Print Network [OSTI]

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...

Bosshard, John

2006-08-16T23:59:59.000Z

46

Graph-based retrospective 4D Image construction from free-breathing MRI slice acquisitions  

E-Print Network [OSTI]

. Campbell3 1 Medical Image Processing Group, Department of Radiology, University of Pennsylvania developed [3, 4]. For pediatric imaging, x-ray radiation becomes a primary concern and MRI remains as the de facto choice. The pediatric subjects we deal with often suffer from extreme malformations of their chest

Ciesielski, Krzysztof Chris

47

A Prospective Study of the Utility of Magnetic Resonance Imaging in Determining Candidacy for Partial Breast Irradiation  

SciTech Connect (OSTI)

Purpose: Retrospective data have demonstrated that breast magnetic resonance imaging (MRI) may change a patient's eligibility for partial breast irradiation (PBI) by identifying multicentric, multifocal, or contralateral disease. The objective of the current study was to prospectively determine the frequency with which MRI identifies occult disease and to establish clinical factors associated with a higher likelihood of MRI prompting changes in PBI eligibility. Methods and Materials: At The University of Chicago, women with breast cancer uniformly undergo MRI in addition to mammography and ultrasonography. From June 2009 through May 2011, all patients were screened prospectively in a multidisciplinary conference for PBI eligibility based on standard imaging, and the impact of MRI on PBI eligibility according to National Surgical Adjuvant Breast and Bowel Project protocol B-39/Radiation Therapy Oncology Group protocol 0413 entry criteria was recorded. Univariable analysis was performed using clinical characteristics in both the prospective cohort and in a separate cohort of retrospectively identified patients. Pooled analysis was used to derive a scoring index predictive of the risk that MRI would identify additional disease. Results: A total of 521 patients were screened for PBI eligibility, and 124 (23.8%) patients were deemed eligible for PBI based on standard imaging. MRI findings changed PBI eligibility in 12.9% of patients. In the pooled univariable analysis, tumor size ?2 cm on mammography or ultrasonography (P=.02), age <50 years (P=.01), invasive lobular histology (P=.01), and HER-2/neu amplification (P=.01) were associated with a higher likelihood of MRI changing PBI eligibility. A predictive score was generated by summing the number of significant risk factors. Patients with a score of 0, 1, 2, and 3 had changes to eligibility based on MRI findings in 2.8%, 13.2%, 38.1%, and 100%, respectively (P<.0001). Conclusions: MRI identified additional disease in a significant number of patients eligible for PBI, based on standard imaging. Clinical characteristics may be useful in directing implementation of MRI in the staging of PBI candidates.

Dorn, Paige L.; Al-Hallaq, Hania A.; Haq, Farah; Goldberg, Mira [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States)] [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States); Abe, Hiroyuki [Department of Radiology, University of Chicago Medical Center, Chicago, Illinois (United States)] [Department of Radiology, University of Chicago Medical Center, Chicago, Illinois (United States); Hasan, Yasmin [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States)] [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States); Chmura, Steven J., E-mail: schmura@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States)

2013-03-01T23:59:59.000Z

48

Variability in functional magnetic resonance imaging : influence of the baseline vascular state and physiological fluctuations  

E-Print Network [OSTI]

cortex by magnetic resonance imaging. Science. 254, 716-719.cortex by magnetic resonance imaging. Science. 254, 716-719.cortex by magnetic resonance imaging. Science. 254, 716-719.

Behzadi, Yashar

2006-01-01T23:59:59.000Z

49

TH?D?201C?08: Multi?Modal MRI SPECT and CT Imaging of Theranostic Nanoplatforms  

Science Journals Connector (OSTI)

Purpose: The development of non?invasive imaging techniques for the assessment of cancer treatment is rapidly becoming highly important. Magnetic Cationic Liposomes (MCL) that carry a cargo of anti?cancer drugs and magnetic nanoparticles that will selectively target primary and metastatic cancertumorsdeliver drugs to them and visualize their effects through magnetic resonance imaging(MRI)single photon emission computed tomography(SPECT) and fluorescence spectroscopy. The aim of the present study is to evaluate MCL as a versatile theranostic nanoplatform for enhanced drug deliveryimaging and monitoring of cancer treatment. Materials and Method: Poly?ethyleneglycol (PEG) coated cationic liposomes are loaded with superparamagnetic iron oxide nanoparticles (SPIONS) and tagged with the radioisotope Indium?111. MCL was administered to SCID mouse with metastatic (B16?F10) melanoma grown in the right flank. Pre?injection and post?injection MR and SPECT/CT images were used to assess response to magnetic targeting effects and tumor and organ distribution. Results:Tumor signal intensities in T2 weighted images decreased an average of 20±5% and T2* values decreased and average of 14±7ms in the absence of magnetic targeting. This compares to an average signal decrease of 57±12% and a decrease in T2* relaxation times of 27±8ms with the aid of external magnet showing up to 2?fold greater accumulation by magnetic targeting. SPECT/CT images showed the localization and distribution of MCL in the tumor.Conclusion: MR SPECT/CT and biodistribution analyses clearly show the efficacy of MCL as MRI contrast agents prove the use of magnetic guidance and demonstrate the potential of MCL as agents for imaging guidance and therapeutic delivery.

F Reynoso; E Gultepe; A Jhaveri; P Kulkarni; B Gershman; C Ferris; R Campbell; M Harisinghani; S Sridhar

2010-01-01T23:59:59.000Z

50

Effectiveness of the Finite Impulse Response Model in Content-based fMRI Image Retrieval  

E-Print Network [OSTI]

to diagnose brain disorders, by looking at the clinical history of persons with similar fMRI patterns; 2 a huge database of documents and images. In an IR framework, as in classification tasks, a dataset datasets from a very large database, in which it is generally difficult to assign class labels to each

51

A generative model for activations in functional MRI  

E-Print Network [OSTI]

Detection of brain activity and selectivity using functional magnetic resonance imaging (fMRI) provides unique insight into the underlying functional properties of the brain. We propose a generative model that jointly ...

Sridharan, Ramesh

2011-01-01T23:59:59.000Z

52

Metal-substituted protein MRI contrast agents engineered for enhanced relaxivity and ligand sensitivity  

E-Print Network [OSTI]

Engineered metalloproteins constitute a flexible new class of analyte-sensitive molecular imaging agents detectable by magnetic resonance imaging (MRI), but their contrast effects are generally weaker than synthetic agents. ...

Lelyveld, Victor S.

53

Magnetic Resonance Imaging-Based Radiation-Absorbed Dose Estimation of 166Ho Microspheres in Liver Radioembolization  

Science Journals Connector (OSTI)

Purpose To investigate the potential of magnetic resonance imaging (MRI) for accurate assessment of the three-dimensional 166Ho activity distribution to estimate radiation-absorbed dose distributions in 166Ho-loaded poly (L-lactic acid) microsphere (166Ho-PLLA-MS) liver radioembolization. Methods and Materials MRI, computed tomography (CT), and single photon emission CT (SPECT) experiments were conducted on an anthropomorphic gel phantom with tumor-simulating gel samples and on an excised human tumor-bearing liver, both containing known amounts of 166Ho-PLLA-MS. Three-dimensional radiation-absorbed dose distributions were estimated at the voxel level by convolving the 166Ho activity distribution, derived from quantitative MRI data, with a 166Ho dose point-kernel generated by MCNP (Monte Carlo N-Particle transport code) and from Medical Internal Radiation Dose Pamphlet 17. MRI-based radiation-absorbed dose distributions were qualitatively compared with CT and autoradiography images and quantitatively compared with SPECT-based dose distributions. Both MRI- and SPECT-based activity estimations were validated against dose calibrator measurements. Results Evaluation on an anthropomorphic phantom showed that MRI enables accurate assessment of local 166Ho-PLLA-MS mass and activity distributions, as supported by a regression coefficient of 1.05 and a correlation coefficient of 0.99, relating local MRI-based mass and activity calculations to reference values obtained with a dose calibrator. Estimated MRI-based radiation-absorbed dose distributions of 166Ho-PLLA-MS in an ex vivo human liver visually showed high correspondence to SPECT-based radiation-absorbed dose distributions. Quantitative analysis revealed that the differences in local and total amounts of 166Ho-PLLA-MS estimated by MRI, SPECT, and the dose calibrator were within 10%. Excellent agreement was observed between MRI- and SPECT-based dose–volume histograms. Conclusions Quantitative MRI was demonstrated to provide accurate three-dimensional 166Ho-PLLA-MS activity distributions, enabling localized intrahepatic radiation-absorbed dose estimation by convolution with a 166Ho dose point-kernel for liver radioembolization treatment optimization and evaluation.

Peter R. Seevinck; Gerrit H. van de Maat; Tim C. de Wit; Maarten A.D. Vente; Johannes F.W. Nijsen; Chris J.G. Bakker

2012-01-01T23:59:59.000Z

54

Metalloporphyrin Enhancement of Magnetic Resonance Imaging of Human Tumor Xenografts in Nude Mice  

Science Journals Connector (OSTI)

...Weizmann Institute of Science, Rehovot 76100...should be addressed. Magnetic resonance imaging...Multicellular Spheroids: Magnetic Resonance Microimaging1...Weiunann institute of Science, Rehovot 76100, Israel ABSTRACT Magnetic resonance imaging...

Philip Furmanski and Clifford Longley

1988-08-15T23:59:59.000Z

55

Folic Acid-Conjugated MnO Nanoparticles as a T1 Contrast Agent for Magnetic Resonance Imaging of Tiny Brain Gliomas  

Science Journals Connector (OSTI)

Folic Acid-Conjugated MnO Nanoparticles as a T1 Contrast Agent for Magnetic Resonance Imaging of Tiny Brain Gliomas ... Detection of brain gliomas at the earliest stage is of great importance to improve the outcomes but remains the most challenging task. ... Accordingly, the in vivo MR images demonstrated that MnO-TETT-FA NPs could efficiently enhance the MRI contrast for tiny brain gliomas. ...

Ning Chen; Chen Shao; Yanming Qu; Shuai Li; Wei Gu; Tingting Zheng; Ling Ye; Chunjiang Yu

2014-10-21T23:59:59.000Z

56

An MRI Segmentation Framework for Brains with Anatomical Marcelinus Prastawa  

E-Print Network [OSTI]

An MRI Segmentation Framework for Brains with Anatomical Deviations Marcelinus Prastawa;ABSTRACT MARCELINUS PRASTAWA: An MRI Segmentation Framework for Brains with Anatomical Deviations (Under the direction of Guido Gerig, Ph.D.) The segmentation of brain Magnetic Resonance (MR) images, where the brain

Whitton, Mary C.

57

Automatic Tissue Classification for the Human Head from Multispectral MRI  

E-Print Network [OSTI]

1 Automatic Tissue Classification for the Human Head from Multispectral MRI Tolga Tasdizen, David for classifying multispectral MR scans of the human head into nine tissue classes. User initialization is adopted. #12;Chapter 1 Introduction Classification of head magnetic resonance imaging (MRI) data

Utah, University of

58

Instrumentation for parallel magnetic resonance imaging  

E-Print Network [OSTI]

of the art of parallel MR imaging. First, a low-cost desktop MR scanner was developed (< $13,000) for imaging small samples (2.54 cm fields-of view) at low magnetic field strengths (< 0.25 T). The performance of the prototype was verified through bench...

Brown, David Gerald

2007-04-25T23:59:59.000Z

59

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

60

Pretreatment Endorectal Coil Magnetic Resonance Imaging Findings Predict Biochemical Tumor Control in Prostate Cancer Patients Treated With Combination Brachytherapy and External-Beam Radiotherapy  

SciTech Connect (OSTI)

Purpose: To investigate the utility of endorectal coil magenetic resonance imaging (eMRI) in predicting biochemical relapse in prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Methods and Materials: Between 2000 and 2008, 279 men with intermediate- or high-risk prostate cancer underwent eMRI of their prostate before receiving brachytherapy and supplemental intensity-modulated radiotherapy. Endorectal coil MRI was performed before treatment and retrospectively reviewed by two radiologists experienced in genitourinary MRI. Image-based variables, including tumor diameter, location, number of sextants involved, and the presence of extracapsular extension (ECE), were incorporated with other established clinical variables to predict biochemical control outcomes. The median follow-up was 49 months (range, 1-13 years). Results: The 5-year biochemical relapse-free survival for the cohort was 92%. Clinical findings predicting recurrence on univariate analysis included Gleason score (hazard ratio [HR] 3.6, p = 0.001), PSA (HR 1.04, p = 0.005), and National Comprehensive Cancer Network risk group (HR 4.1, p = 0.002). Clinical T stage and the use of androgen deprivation therapy were not correlated with biochemical failure. Imaging findings on univariate analysis associated with relapse included ECE on MRI (HR 3.79, p = 0.003), tumor size (HR 2.58, p = 0.04), and T stage (HR 1.71, p = 0.004). On multivariate analysis incorporating both clinical and imaging findings, only ECE on MRI and Gleason score were independent predictors of recurrence. Conclusions: Pretreatment eMRI findings predict for biochemical recurrence in intermediate- and high-risk prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Gleason score and the presence of ECE on MRI were the only significant predictors of biochemical relapse in this group of patients.

Riaz, Nadeem [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Afaq, Asim; Akin, Oguz [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Pei Xin; Kollmeier, Marisa A.; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Hricak, Hedvig [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "resonance imaging mri" from the National Library of EnergyBeta (NLEBeta).
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61

Roadmap: Radiologic Imaging Sciences Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences ­ Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) - Bachelor of Radiologic Imaging Sciences Technology [RE-BRIT-RIS-MRHA] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 1-May-13/LNHD This roadmap is a recommended

Sheridan, Scott

62

Roadmap: Radiologic Imaging Sciences -Magnetic Resonance Imaging (with AAS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences - Magnetic Resonance Imaging (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-MRRT] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 1-May-13/LNHD This roadmap is a recommended semester

Sheridan, Scott

63

Roadmap: Radiologic Imaging Sciences Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences ­ Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) - Bachelor of Radiologic Imaging Sciences Technology [RE-BRIT-RIS-MRHA] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 11-Apr-12/LNHD This roadmap is a recommended

Sheridan, Scott

64

Roadmap: Radiologic Imaging Sciences -Magnetic Resonance Imaging (with AAS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences - Magnetic Resonance Imaging (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-MRRT] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 21-May-12/LNHD This roadmap is a recommended semester

Sheridan, Scott

65

High resolution resonance ionization imaging detector and method  

DOE Patents [OSTI]

A resonance ionization imaging device (RIID) and method for imaging objects using the RIID are provided, the RIID system including a RIID cell containing an ionizable vapor including monoisotopic atoms or molecules, the cell being positioned to intercept scattered radiation of a resonance wavelength .lambda..sub.1 from the object which is to be detected or imaged, a laser source disposed to illuminate the RIID cell with laser radiation having a wavelength .lambda..sub.2 or wavelengths .lambda..sub.2, .lambda..sub.3 selected to ionize atoms in the cell that are in an excited state by virtue of having absorbed the scattered resonance laser radiation, and a luminescent screen at the back surface of the RIID cell which presents an image of the number and position of charged particles present in the RIID cell as a result of the ionization of the excited state atoms. The method of the invention further includes the step of initially illuminating the object to be detected or imaged with a laser having a wavelength selected such that the object will scatter laser radiation having the resonance wavelength .lambda..sub.1.

Winefordner, James D. (Gainesville, FL); Matveev, Oleg I. (Gainesville, FL); Smith, Benjamin W. (Gainesville, FL)

1999-01-01T23:59:59.000Z

66

Identification of breast calcification using magnetic resonance imaging  

SciTech Connect (OSTI)

MRI phase and magnitude images provide information about local magnetic field variation ({Delta}B{sub 0}), which can consequently be used to understand tissue properties. Often, phase information is discarded. However, corrected phase images are able to produce contrast as a result of magnetic susceptibility differences and local field inhomogeneities due to the presence of diamagnetic and paramagnetic substances. Three-dimensional (3D) susceptibility weighted imaging (SWI) can be used to probe changes in MRI phase evolution and, subsequently, result in an alternate form of contrast between tissues. For example, SWI has been useful in the assessment of negative phase induced {Delta}B{sub 0} modulation due to the presence of paramagnetic substances such as iron. Very little, however, has been done to assess positive phase induced contrast changes resulting from the presence of diamagnetic substances such as precipitated calcium. As ductal carcinoma in situ, which is the precursor of invasive ductal cancer, is often associated with breast microcalcification, the authors proposed using SWI as a possible visualization technique. In this study, breast phantoms containing calcifications (0.4-1.5 mm) were imaged using mammography, computed tomography (CT), and SWI. Corrected phase and magnitude images acquired using SWI allowed identification and correlation of all calcifications seen on CT. As the approach is a 3D technique, it could potentially allow for more accurate localization and biopsy and maybe even reduce the use of gadolinium contrast. Furthermore, the approach may be beneficial to women with dense breast tissue where the ability to detect microcalcification with mammography is reduced.

Fatemi-Ardekani, Ali; Boylan, Colm; Noseworthy, Michael D. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada) and Imaging Research Centre, Brain-Body Institute, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada); Diagnostic Imaging, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada) and Department of Radiology, McMaster University, Hamilton, Ontario L8N 3Z5 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Imaging Research Centre, Brain-Body Institute, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada); Diagnostic Imaging, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada); Department of Radiology, McMaster University, Hamilton, Ontario L8N 3Z5 (Canada) and Electrical and Computer Engineering, and School of Biomedical Engineering, McMaster University, Hamilton, Ontario L8S 4K1 (Canada)

2009-12-15T23:59:59.000Z

67

Fluorescently Detectable Magnetic Resonance Imaging Agents  

Science Journals Connector (OSTI)

Images acquired of single cells after injection with these bifunctional agents enabled us to follow the relative motions and reorganizations of different cell layers during amphibian gastrulation and neurulation in Xenopus laevis embryos. ... Approximately 10 nL of a buffered aqueous solution containing each compound at a known concentration was injected into the animal pole of one cell in a two-cell embryo. ... These molecules were designed to be used for embryonic cell lineage analyses. ...

Martina M. Hüber; Andrea B. Staubli; Karen Kustedjo; Mike H. B. Gray; John Shih; Scott E. Fraser; Russell E. Jacobs; Thomas J. Meade

1998-02-27T23:59:59.000Z

68

Neurovascular coupling to D2/D3 dopamine receptor occupancy using simultaneous PET/functional MRI  

E-Print Network [OSTI]

This study employed simultaneous neuroimaging with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to demonstrate the relationship between changes in receptor occupancy measured by PET ...

Sander, Christin Yen-Ming

69

3D He-3 diffusion MRI as a local in vivo morphometric tool to...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

diffusion MRI as a local in vivo morphometric tool to evaluate emphysematous rat lungs. Abstract: In this work, we validate 3He magnetic resonance imaging as a non-invasive...

70

Spectrally Resolved Magnetic Resonance Imaging of the XenonBiosensor  

SciTech Connect (OSTI)

Due to its ability to non-invasively record images, as well as elucidate molecular structure, nuclear magnetic resonance is the method of choice for applications as widespread as chemical analysis and medical diagnostics. Its detection threshold is, however, limited by the small polarization of nuclear spins in even the highest available magnetic fields. This limitation can, under certain circumstances, be alleviated by using hyper-polarized substances. Xenon biosensors make use of the sensitivity gain of hyperpolarized xenon to provide magnetic resonance detection capability for a specific low-concentration target. They consist of a cryptophane cage, which binds one xenon atom, and which has been connected via a linker to a targeting moiety such as a ligand or antibody. Recent work has shown the possibility of using the xenon biosensor to detect small amounts of a substance in a heterogeneous environment by NMR. Here, we demonstrate that magnetic resonance (MR) provides the capability to obtain spectrally and spatially resolved images of the distribution of immobilized biosensor, opening the possibility for using the xenon biosensor for targeted imaging.

Hilty, Christian; Lowery, Thomas; Wemmer, David; Pines, Alexander

2005-07-15T23:59:59.000Z

71

PRACTICAL PARALLEL IMAGING COMPRESSED SENSING MRI: SUMMARY OF TWO YEARS OF EXPERIENCE IN ACCELERATING BODY MRI OF PEDIATRIC PATIENTS.  

E-Print Network [OSTI]

IN ACCELERATING BODY MRI OF PEDIATRIC PATIENTS. SS Vasanawala2 MJ Murphy 1 MT Alley2 P Lai3 K Keutzer1 JM Pauly4 M Lustig1 1 Electrical Engineering and Computer Science, University of California, Berkeley 2 Radiology- ing of pediatric patients. It is a joint-effort by teams from UC Berkeley, Stanford University and GE

Lustig, Michael 'Miki'

72

Noninvasive Assessment of Tumor Microenvironment Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging and {sup 18}F-Fluoromisonidazole Positron Emission Tomography Imaging in Neck Nodal Metastases  

SciTech Connect (OSTI)

Purpose: To assess noninvasively the tumor microenvironment of neck nodal metastases in patients with head-and-neck cancer by investigating the relationship between tumor perfusion measured using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hypoxia measured by {sup 18}F-fluoromisonidazole ({sup 18}F-FMISO) positron emission tomography (PET). Methods and Materials: Thirteen newly diagnosed head-and-neck cancer patients with metastatic neck nodes underwent DCE-MRI and {sup 18}F-FMISO PET imaging before chemotherapy and radiotherapy. The matched regions of interests from both modalities were analyzed. To examine the correlations between DCE-MRI parameters and standard uptake value (SUV) measurements from {sup 18}F-FMISO PET, the nonparametric Spearman correlation coefficient was calculated. Furthermore, DCE-MRI parameters were compared between nodes with {sup 18}F-FMISO uptake and nodes with no {sup 18}F-FMISO uptake using Mann-Whitney U tests. Results: For the 13 patients, a total of 18 nodes were analyzed. The nodal size strongly correlated with the {sup 18}F-FMISO SUV ({rho} = 0.74, p < 0.001). There was a strong negative correlation between the median k{sub ep} (redistribution rate constant) value ({rho} = -0.58, p = 0.042) and the {sup 18}F-FMISO SUV. Hypoxic nodes (moderate to severe {sup 18}F-FMISO uptake) had significantly lower median K{sup trans} (volume transfer constant) (p = 0.049) and median k{sub ep} (p = 0.027) values than did nonhypoxic nodes (no {sup 18}F-FMISO uptake). Conclusion: This initial evaluation of the preliminary results support the hypothesis that in metastatic neck lymph nodes, hypoxic nodes are poorly perfused (i.e., have significantly lower K{sup trans} and k{sub ep} values) compared with nonhypoxic nodes.

Jansen, Jacobus [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Schoeder, Heiko [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Wang Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2010-08-01T23:59:59.000Z

73

Noninvasive Monitoring of Microvascular Changes With Partial Irradiation Using Dynamic Contrast-Enhanced and Blood Oxygen Level-Dependent Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Purpose: The microvasculature of a tumor plays an important role in its response to radiation therapy. Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and blood oxygen level-dependent (BOLD) MRI are both sensitive to vascular characteristics. The present study proposed a partial irradiation approach to a xenograft tumor to investigate the intratumoral response to radiation therapy using DCE and BOLD MRI. Methods and Materials: TRAMP-C1 tumors were grown in C57BL/6J mice. Partial irradiation was performed on the distal half of the tumor with a single dose of 15 Gy. DCE MRI was performed to derive the endothelium transfer constant, K{sup trans}, using pharmacokinetic analysis. BOLD MRI was performed using quantitative R2* measurements with carbogen breathing. The histology of the tumor was analyzed using hematoxylin and eosin staining and CD31 staining to detect endothelial cells. The differences between the irradiated and nonirradiated regions of the tumor were assessed using K{sup trans} values, ?R2* values in response to carbogen and microvascular density (MVD) measurements. Results: A significantly increased K{sup trans} and reduced BOLD response to carbogen were found in the irradiated region of the tumor compared with the nonirradiated region (P<.05). Histologic analysis showed a significant aggregation of giant cells and a reduced MVD in the irradiated region of the tumor. The radiation-induced difference in the BOLD response was associated with differences in MVD and K{sup trans}. Conclusions: We demonstrated that DCE MRI and carbogen-challenge BOLD MRI can detect differential responses within a tumor that may potentially serve as noninvasive imaging biomarkers to detect microvascular changes in response to radiation therapy.

Lin, Yu-Chun [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Electrical Engineering, Chang Gung University, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Jiun-Jie [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Hong, Ji-Hong [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lin, Yi-Ping [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)] [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Wai, Yau-Yau; Ng, Shu-Hang; Wu, Yi-Ming [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Chun-Chieh, E-mail: jjwang@adm.cgmh.org.tw [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)

2013-04-01T23:59:59.000Z

74

Functional, perfusion and diffusion MRI of acute focal ischemic brain injury  

E-Print Network [OSTI]

magnetic resonance imaging (MRI) with a temporal resolution of 30 mins was performed on permanent. With permanent ischemia (n ¼ 11), forepaw stimulation fMRI response in the primary somatosensory cortices was lost, although vascular coupling (CO2 response) was intact in some animals. Control experiments

Duong, Timothy Q.

75

Distribution of Liposomes into Brain and Rat Brain Tumor Models by Convection-Enhanced Delivery Monitored with Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

...Convection-Enhanced Delivery Monitored with Magnetic Resonance Imaging Ryuta Saito...B, T 1-weighted coronal magnetic resonance image of a 9L-2 rat...assistance, Dr. David Newitt (Magnetic Resonance Science Center, University of California...

Ryuta Saito; John R. Bringas; Tracy R. McKnight; Michael F. Wendland; Christoph Mamot; Daryl C. Drummond; Dmitri B. Kirpotin; John W. Park; Mitchel S. Berger; and Krys S. Bankiewicz

2004-04-01T23:59:59.000Z

76

White matter microstructure on diffusion tensor imaging is associated with conventional magnetic resonance imaging findings and  

E-Print Network [OSTI]

White matter microstructure on diffusion tensor imaging is associated with conventional magnetic to evaluate white matter architecture after preterm birth. The goals were (1) to compare white matter if sex, gestational age, birth- weight, white matter injury score from conventional magnetic resonance

Grill-Spector, Kalanit

77

Active resonant subwavelength grating for scannerless range imaging sensors.  

SciTech Connect (OSTI)

In this late-start LDRD, we will present a design for a wavelength-agile, high-speed modulator that enables a long-term vision for the THz Scannerless Range Imaging (SRI) sensor. It takes the place of the currently-utilized SRI micro-channel plate which is limited to photocathode sensitive wavelengths (primarily in the visible and near-IR regimes). Two of Sandia's successful technologies--subwavelength diffractive optics and THz sources and detectors--are poised to extend the capabilities of the SRI sensor. The goal is to drastically broaden the SRI's sensing waveband--all the way to the THz regime--so the sensor can see through image-obscuring, scattering environments like smoke and dust. Surface properties, such as reflectivity, emissivity, and scattering roughness, vary greatly with the illuminating wavelength. Thus, objects that are difficult to image at the SRI sensor's present near-IR wavelengths may be imaged more easily at the considerably longer THz wavelengths (0.1 to 1mm). The proposed component is an active Resonant Subwavelength Grating (RSG). Sandia invested considerable effort on a passive RSG two years ago, which resulted in a highly-efficient (reflectivity greater than gold), wavelength-specific reflector. For this late-start LDRD proposal, we will transform the passive RSG design into an active laser-line reflector.

Kemme, Shanalyn A.; Nellums, Robert O.; Boye, Robert R.; Peters, David William

2006-11-01T23:59:59.000Z

78

Compact surface plasmon resonance imaging sensing system based on general optoelectronic components  

Science Journals Connector (OSTI)

We present a simple surface plasmon resonance imaging (SPRi) sensing system based on some common optoelectronic devices in this paper. Using an optical fiber based SPR sensor as...

Peng, Wei; Liu, Yun; Fang, Peng; Liu, Xiuxin; Gong, Zhenfeng; Wang, Hanqi; Cheng, Fang

2014-01-01T23:59:59.000Z

79

Helical Tomotherapy Planning for Lung Cancer Based on Ventilation Magnetic Resonance Imaging  

SciTech Connect (OSTI)

To investigate the feasibility of lung ventilation-based treatment planning, computed tomography and hyperpolarized (HP) helium-3 (He-3) magnetic resonance imaging (MRI) ventilation images of 6 subjects were coregistered for intensity-modulated radiation therapy planning in Tomotherapy. Highly-functional lungs (HFL) and less-functional lungs (LFL) were contoured based on their ventilation image intensities, and a cylindrical planning-target-volume was simulated at locations adjacent to both HFL and LFL. Annals of an anatomy-based plan (Plan 1) and a ventilation-based plan (Plan 2) were generated. The following dosimetric parameters were determined and compared between the 2 plans: percentage of total/HFL volume receiving {>=}20 Gy, 15 Gy, 10 Gy, and 5 Gy (TLV{sub 20}, HFLV{sub 20}, TLV{sub 15}, HFLV{sub 15}, TLV{sub 10}, HFLV{sub 10}, TLV{sub 5}, HFLV{sub 5}), mean total/HFL dose (MTLD/HFLD), maximum doses to all organs at risk (OARs), and target dose conformality. Compared with Plan 1, Plan 2 reduced mean HFLD (mean reduction, 0.8 Gy), MTLD (mean reduction, 0.6 Gy), HFLV{sub 20} (mean reduction, 1.9%), TLV{sub 20} (mean reduction, 1.5%), TLV{sub 15} (mean reduction, 1.7%), and TLV{sub 10} (mean reduction, 2.1%). P-values of the above comparisons are less than 0.05 using the Wilcoxon signed rank test. For HFLV{sub 15}, HFLV{sub 10}, TLV{sub 5}, and HTLV{sub 5}, Plan 2 resulted in lower values than plan 1 but the differences are not significant (P-value range, 0.063-0.219). Plan 2 did not significantly change maximum doses to OARs (P-value range, 0.063-0.563) and target conformality (P = 1.000). HP He-3 MRI of patients with lung disease shows a highly heterogeneous ventilation capacity that can be utilized for functional treatment planning. Moderate but statistically significant improvements in sparing functional lungs were achieved using helical tomotherapy plans.

Cai Jing; McLawhorn, Robert [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Altes, Tallisa A.; Lange, Eduard de [Department of Radiology, University of Virginia, Charlottesville, VA (United States); Read, Paul W.; Larner, James M.; Benedict, Stanley H. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Sheng Ke, E-mail: ks2mc@virginia.edu [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

2011-01-01T23:59:59.000Z

80

Directly Mapping Magnetic Field Effects of Neuronal Activity by Magnetic Resonance  

E-Print Network [OSTI]

Directly Mapping Magnetic Field Effects of Neuronal Activity by Magnetic Resonance Imaging Jinhu Xiong,* Peter T. Fox, and Jia-Hong Gao Research Imaging Center, University of Texas Health Science Center at San Antonio, San Antonio, Texas Abstract: Magnetic resonance imaging (MRI) of brain functional

Gabrieli, John

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.


81

A REAL TIME 3D VISUALIZATION PROTOTYPE FOR INTERVENTIONAL MAGNETIC RESONANCE IMAGING  

E-Print Network [OSTI]

A REAL TIME 3D VISUALIZATION PROTOTYPE FOR INTERVENTIONAL MAGNETIC RESONANCE IMAGING JENS FISCHER.weiss@pfh.research.philips.com HEIDRUN SCHUMANN University of Rostock, Computer Science Department, D­18051 Rostock,Germany schumann radiologists during invasive and non­invasive magnetic resonance imaging. We use pre­acquired and real time

Schumann, Heidrun

82

A neural network approach for image reconstruction in electron magnetic resonance tomography  

Science Journals Connector (OSTI)

An object-oriented, artificial neural network (ANN) based, application system for reconstruction of two-dimensional spatial images in electron magnetic resonance (EMR) tomography is presented. The standard back propagation algorithm is utilized to train ... Keywords: Artificial neural networks, Back propagation, Electron magnetic resonance tomography, Filtered back projection, Image reconstruction, Multiplicative algebraic reconstruction technique

D. Christopher Durairaj; Murali C. Krishna; Ramachandran Murugesan

2007-10-01T23:59:59.000Z

83

An Improved Bioluminescence Resonance Energy Transfer Strategy for Imaging Intracellular Events in Single Cells and Living Subjects  

Science Journals Connector (OSTI)

...An Improved Bioluminescence Resonance Energy Transfer Strategy for Imaging Intracellular...org/ ). Bioluminescence resonance energy transfer (BRET) is currently used for...7175-83] mTOR|Bioluminescence resonance energy transfer|Renilla luciferase|Green...

Abhijit De; Andreas Markus Loening; Sanjiv Sam Gambhir

2007-08-01T23:59:59.000Z

84

UNSUPERVISED SEGMENTATION FOR AUTOMATIC DETECTION OF BRAIN TUMORS IN MRI  

E-Print Network [OSTI]

UNSUPERVISED SEGMENTATION FOR AUTOMATIC DETECTION OF BRAIN TUMORS IN MRI A.S. Capelle, O. Alata, C- thod for magnetic resonance images. The aim of this seg- mentation is to divide the brain a pre-segmentation to ex- tract the brain from the head. Then, a second segmentation is done inside

Lefèvre, Sébastien

85

Phase imaging of magnetic nanostructures using resonant soft x-ray holography  

Science Journals Connector (OSTI)

We demonstrate phase imaging by means of resonant soft x-ray holography. Our holographic phase-contrast method utilizes the strong energy-dependence of the refractive index at a characteristic x-ray absorption resonance. The general concept is shown by using a Co?Pd multilayer sample which exhibits random nanosized magnetic domains. By tuning below the Co L-edge resonance, our quantitative and spectroscopic phase method allows high-contrast imaging of nanoscale electronic and magnetic order while increasing the probing depth and decreasing the radiation dose by an order of magnitude. The complex refractive index is quantitatively obtained through the interference between resonant and nonresonant scattering.

A. Scherz; W. F. Schlotter; K. Chen; R. Rick; J. Stöhr; J. Lüning; I. McNulty; Ch. Günther; F. Radu; W. Eberhardt; O. Hellwig; S. Eisebitt

2007-12-17T23:59:59.000Z

86

Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image  

E-Print Network [OSTI]

SQUID sensors demonstrate the effectiveness of this data consistency constraint and sparsity prior-mail: fhlin@ntu.edu.tw Introduction MRI has become an indispensible resource in clinical medicine because

87

DOT imaging of the developing brain: A validation study against functional MRI  

Science Journals Connector (OSTI)

In this work, we present a subject-matched comparison between fcDOT and fcMRI maps obtained in a cohort of full-term neonates. Our results demonstrate the potential of functional...

Ferradal, Silvina L; Liao, Steve M; Eggebrecht, Adam T; Shimony, Joshua; Inder, Terrie E; Culver, Joseph P; Smyser, Christopher D

88

Int. J. Patt. Recog. Art. Intell., Special Issue on MR Brain Image Analysis, 1997 1 An Integrated Approach for Locating Neuroanatomical Structure from MRI1  

E-Print Network [OSTI]

Int. J. Patt. Recog. Art. Intell., Special Issue on MR Brain Image Analysis, 1997 1 An Integrated Approach for Locating Neuroanatomical Structure from MRI1 Lawrence H. Staib , Amit Chakrabortyy and James S results on synthetic and MR brain images show a significant improvement is achieved as a consequence

Duncan, James S.

89

Int. J. Patt. Recog. Art. Intell., Special Issue on MR Brain Image Analysis, 1997 1 An Integrated Approach for Locating Neuroanatomical Structure from MRI 1  

E-Print Network [OSTI]

Int. J. Patt. Recog. Art. Intell., Special Issue on MR Brain Image Analysis, 1997 1 An Integrated Approach for Locating Neuroanatomical Structure from MRI 1 Lawrence H. Staib \\Lambda , Amit Chakraborty y gradient­ based surface finder. Experimental results on synthetic and MR brain images show a significant

90

T2*-weighted magnetic resonance imaging used to detect coagulative necrosis in tissue  

E-Print Network [OSTI]

to prevent unnecessary collateral damage to surrounding healthy tissue. This research focuses on using T2*-weighted FLASH magnetic resonance imaging to detect irreversible changes in i . n vitro bovine liver tissue and tissuesimulating polyacrylamide gel...

Van Hyfte, John Bruce

1997-01-01T23:59:59.000Z

91

MRI- Versus CT-Based Volume Delineation of Lumpectomy Cavity in Supine Position in Breast-Conserving Therapy: An Exploratory Study  

SciTech Connect (OSTI)

Purpose: To examine magnetic resonance imaging (MRI) and computed tomography (CT) for lumpectomy cavity (LC) volume delineation in supine radiotherapy treatment position and to assess the interobserver variability. Methods and Materials: A total of 15 breast cancer patients underwent a planning CT and directly afterward MRI in supine radiotherapy treatment position. Then, 4 observers (2 radiation oncologists and 2 radiologists) delineated the LC on the CT and MRI scans and assessed the cavity visualization score (CVS). The CVS, LC volume, conformity index (CI), mean shift of the center of mass (COM), with the standard deviation, were quantified for both CT and MRI. Results: The CVS showed that MRI and CT provide about equal optimal visibility of the LC. If the CVS was high, magnetic resonance imaging provided more detail of the interfaces of the LC seroma with the unaffected GBT. MRI also pictured in more detail the interfaces of axillary seromas (if present) with their surroundings and their relationship to the LC. Three observers delineated smaller, and one observer larger, LC volumes comparing the MRI- and CT-derived delineations. The mean {+-} standard deviation CI was 32% {+-} 25% for MRI and 52% {+-} 21% for CT. The mean {+-} standard deviation COM shift was 11 {+-} 10 mm (range 1-36) for MRI and 4 {+-} 3 mm (range 1-10) for CT. Conclusions: MRI does not add additional information to CT in cases in which the CVS is assessed as low. The conformity (CI) is lower for MRI than for CT, especially at a low CVS owing to greater COM shifts for MRI, probably caused by inadequate visibility of the surgical clips on magnetic resonance (MR) images. The COM shifts seriously dictate a decline in the CI more than the variability of the LC volumes does. In cases in which MRI provides additional information, MRI must be combined with the CT/surgical clip data.

Giezen, Marina, E-mail: marinagiezen@zonnet.nl [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Kouwenhoven, Erik [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Scholten, Astrid N. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Coerkamp, Emile G.; Heijenbrok, Mark [Department of Radiology, Medical Center Haaglanden, The Hague (Netherlands); Jansen, Wim P.A. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Mast, Mirjam E.; Petoukhova, Anna L. [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Struikmans, Henk [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands)

2012-03-15T23:59:59.000Z

92

Effectiveness of the Finite Impulse Response Model in Content-Based fMRI Image Retrieval  

E-Print Network [OSTI]

to diagnose brain disorders, by looking at the clinical history of persons with similar fMRI This work]. This framework is best known for applications such as search engines, which usually have a huge database large database, in which it is generally difficult to assign class labels to each dataset. In contrast

93

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, Name ID# Date  

E-Print Network [OSTI]

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, 2014-2015 Name ID Intro to Sociology 3 DLS Social Sciences course in a second field 3 CID HLTHST 382 Research Methods Pharmacology and Contrast Medias RADSCI 430 Comparative Sectional Imaging RADSCI 440 Principles of Magnetic

Barrash, Warren

94

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, Name ID# Date  

E-Print Network [OSTI]

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, 2012-2013 Name ID Intro to Sociology 3 DLS Social Sciences course in a second field 3 CID HLTHST 382 Research Methods Pharmacology and Contrast Medias RADSCI 430 Comparative Sectional Imaging RADSCI 440 Principles of Magnetic

Barrash, Warren

95

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, Name ID# Date  

E-Print Network [OSTI]

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, 2013-2014 Name ID Intro to Sociology 3 DLS Social Sciences course in a second field 3 CID HLTHST 382 Research Methods Pharmacology and Contrast Medias RADSCI 430 Comparative Sectional Imaging RADSCI 440 Principles of Magnetic

Barrash, Warren

96

Medical Image Segmentation Xiaolei Huang  

E-Print Network [OSTI]

(CAT), Magnetic Resonance Imaging (MRI), Ultrasound, and X-Ray, in standard DICOM formats are often for searching and mining in medical image archives. A chal- lenging problem is to segment regions with boundary-based classification approaches. We first review these two categories of methods and discuss the potential

Huang, Xiaolei

97

Intra-pixel multispectral processing of magnetic resonance brain images for tissue characterisation  

Science Journals Connector (OSTI)

Magnetic resonance (MR) image analysis is generally performed by spatial domainbased image processing, referred to as inter-pixel image processing, which takes advantage of spatial correlation among sample pixels. Unfortunately, in many areas, several tissue substances are usually present and mixed in a single image pixel in which such an inter-pixel processing either fails or is ineffective. To resolve this dilemma, this paper develops an unconventional approach, called intra-pixel processing, which considers MR images as multispectral images where a multispectral MR image pixel is actually a pixel vector, of which each component is captured by a particular image pulse sequence used for MR image acquisition. Since the commonly used receiver operating characteristic (ROC) curves cannot directly deal with the issues arising in intra-pixel processing, a 3D ROC analysis is developed by including a parameter t as the third dimension that represents abundance fractions thresholded by ?.

Clayton Chi-Chang Chen; Englin Wong; Hsian-Min Chen; Shih-Yu Chen; Jyh-Wen Chai; Ching-Wen Yang; San-Kan Lee; Yong-Kie Wong; Chein-I Chang

2013-01-01T23:59:59.000Z

98

High Field Magnetic Resonance Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

99

Cavum septi pellucidi in first-episode schizophrenia and first-episode affective psychosis: an MRI study  

E-Print Network [OSTI]

(CSP) in schizophrenia may reflect neurodevelopmental abnormalities in midline structures of the brain. The relationship, however, between abnormal CSP and clinical symptoms, and with abnormalities in other limbic resonance imaging (MRI). CSP on six slices or more on 0.9375-mm resampled coronal images was categorized

100

The development of magnetic resonance imaging for the determination of porosity in reservoir core samples  

E-Print Network [OSTI]

to increase. This is the resonance condition and is the principle upon which magnetic resonance imaging is founded. The resonance frequency, tu, is directly proportional to the magnetic field and can be expressed as: where y is the gyromagnetic ratio and H... system is also precessing about y' with the same rotational frequency as M. This is the rotating frame of reference. By convention, z' is set equal to z and, therefore, H . As long as H remains at a constant strength and is the only field applied...

Sherman, Byron Blake

2012-06-07T23:59:59.000Z

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.


101

Simultaneous Electroencephalography and Functional Magnetic Resonance Imaging of General Anesthesia  

E-Print Network [OSTI]

It has been long appreciated that anesthetic drugs induce stereotyped changes in electroencephalogram (EEG), but the relationships between the EEG and underlying brain function remain poorly understood. Functional imaging ...

Purdon, Patrick Lee

102

Instrumentation and method for measuring NIR light absorbed in tissue during MR imaging in medical NIRS measurements  

Science Journals Connector (OSTI)

Our goal is to provide a cost-effective method for examining human tissue, particularly the brain, by the simultaneous use of functional magnetic resonance imaging (fMRI) and...

Myllylä, Teemu S; Sorvoja, Hannu S S; Nikkinen, Juha; Tervonen, Osmo; Kiviniemi, Vesa; Myllylä, Risto A

103

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

104

Qualification of a Noninvasive Magnetic Resonance Imaging Biomarker to Assess Tumor Oxygenation  

Science Journals Connector (OSTI)

...23. Ogawa S , Lee TM, Kay AR Tank DW.Brain magnetic resonance imaging with contrast...intensity-modulated radiation therapy for head and neck cancer.Expert Rev Anticancer...Radiation-Induced Toxicity for Patients with Head and Neck Carcinoma in the IMRT Era: A...

Florence Colliez; Marie-Aline Neveu; Julie Magat; Thanh Trang Cao Pham; Bernard Gallez; Bénédicte F. Jordan

2014-11-01T23:59:59.000Z

105

Performance of reimbursement schemes in valuation of technologies: The example of Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

Different reimbursement schemes for health care providers have been developed worldwide. They have evolved over time and have been influenced by politics, costs, patient needs and technological progress. Different methods in the valuation of technologies ... Keywords: Magnetic Resonance Imaging, Valuation, payment, reimbursement schemes, technologies

R. Blankart; J. Schreyögg; R. Busse

2008-08-01T23:59:59.000Z

106

Systematic Review of the Value of Ultrasound and Magnetic Resonance Musculoskeletal Imaging in the Evaluation of Response to Treatment of Gout  

Science Journals Connector (OSTI)

AbstractBackground Imaging may be useful for monitoring response to therapy. Within the OMERACT proposal for the core set domains for outcome measures in chronic gout, serum urate levels, recurrence of gouty flares, tophus regression, and joint damage imaging have been included, among other proposed issues. Objectives To perform a systematic literature review of the usefulness of magnetic resonance imaging (MRI) and ultrasound (US) on assessment of treatment response in patients with gout. Methods MEDLINE, EMBASE, Cochrane Library (up to February 2012), and abstracts presented at the 2010 and 2011 meetings of the American College of Rheumatology and European League Against Rheumatism were searched for treatment studies of any duration and therapeutic options, examining the ability of MRI/US to assess treatment response in gouty patients. Meta-analyses, systematic reviews, randomized clinical trials, cohort and case-control studies and validation studies were included. Quality was appraised using validated scales. Results There were only 3 US published studies in the literature that analyzed US utility on assessment of response to treatment in patients with gout. All of them were prospective case studies with a small number of patients and they were reviewed in a detailed manner. A total of 36 patients with gout were examined with US. All of them had a baseline serum urate >6 mg/dL. US features of gout (double contour sign, hyperechoic spots in synovial fluid, hyperechoic cloudy areas, tophus diameter and volume) achieved significant reduction in patients who reached the objective of uricemia ?6 mg/dL in all the studies; however, patients in whom levels did not drop below 6 mg/dL had no change of US features of gout. Other parameters evaluated in one study included ESR, CRP, number of tender joints (TRN), number of swollen joints, and pain score (SP). All of them decreased with uricemia reduction, but only TRN and SP were statistically significant. No data were found on the value of MRI on treatment response assessment in patients with gout. Conclusions The improvement in ultrasound features shows concurrent validity with uric acid reduction. According to the published evidence, US can be a useful tool for monitoring treatment of gouty patients, although more research is needed. The value of MRI on treatment response assessment in patients with gout remains to be determined.

Virginia Villaverde; María Piedad Rosario; Estíbaliz Loza; Fernando Pérez

2014-01-01T23:59:59.000Z

107

Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields  

DOE Patents [OSTI]

A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

2014-01-21T23:59:59.000Z

108

Development for Hardware for Programming of Spatial Magnetic Field Distributions in Nuclear Magnetic Resonance and Magnetic Resonance Imaging  

E-Print Network [OSTI]

The proposal of a project aimed on a design of hardware for programming 3D Magnetic Field shapes over sample volume in NMR and MRI is described.

Vladimir Korostelev

2012-01-13T23:59:59.000Z

109

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

110

GPU-accelerated denoising of 3D magnetic resonance images  

SciTech Connect (OSTI)

The raw computational power of GPU accelerators enables fast denoising of 3D MR images using bilateral filtering, anisotropic diffusion, and non-local means. In practice, applying these filtering operations requires setting multiple parameters. This study was designed to provide better guidance to practitioners for choosing the most appropriate parameters by answering two questions: what parameters yield the best denoising results in practice? And what tuning is necessary to achieve optimal performance on a modern GPU? To answer the first question, we use two different metrics, mean squared error (MSE) and mean structural similarity (MSSIM), to compare denoising quality against a reference image. Surprisingly, the best improvement in structural similarity with the bilateral filter is achieved with a small stencil size that lies within the range of real-time execution on an NVIDIA Tesla M2050 GPU. Moreover, inappropriate choices for parameters, especially scaling parameters, can yield very poor denoising performance. To answer the second question, we perform an autotuning study to empirically determine optimal memory tiling on the GPU. The variation in these results suggests that such tuning is an essential step in achieving real-time performance. These results have important implications for the real-time application of denoising to MR images in clinical settings that require fast turn-around times.

Howison, Mark; Wes Bethel, E.

2014-05-29T23:59:59.000Z

111

Full Length Article: Color-appearance-model based fusion of gray and pseudo-color images for medical applications  

Science Journals Connector (OSTI)

Fusion of gray and pseudo-color images presents more information of biological tissues in a single image and facilitates the interpretation of multimodalities in medical practice. However, fused results are hampered by the problems of blurred details, ... Keywords: Biomedical image fusion, CIECAM02, Color appearance model (CAM), Magnetic resonance imaging (MRI), Rainbow palette, Ultrasound

Tianjie Li, Yuanyuan Wang, Cai Chang, Na Hu, Yongping Zheng

2014-09-01T23:59:59.000Z

112

Combined PET/MRI scanner  

DOE Patents [OSTI]

A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

Schlyer, David (Bellport, NY); Woody, Craig L. (Setauket, NY); Rooney, William (Miller Place, NY); Vaska, Paul (Sound Beach, NY); Stoll, Sean (Wading River, NY); Pratte, Jean-Francois (Stony Brook, NY); O'Connor, Paul (Bellport, NY)

2007-10-23T23:59:59.000Z

113

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

E-Print Network [OSTI]

&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Co-Chairs of Committee, A. Ted Watson John C. Slattery Committee Members, Randall L. Eubank David M. Ford Michael A. Bevan Head of Department, Kenneth R... Co?Chairs of Advisory Committee: Dr. A. Ted Watson Dr. John C. Slattery Advanced nuclear magnetic resonance (NMR) imaging methodologies have been developed to determine porous media properties associated with fluid flow pro- cesses. This dissertation...

Uh, Jinsoo

2007-04-25T23:59:59.000Z

114

Magnetic Resonance Imaging- Versus Computed Tomography-Based Target Volume Delineation of the Glandular Breast Tissue (Clinical Target Volume Breast) in Breast-Conserving Therapy: An Exploratory Study  

SciTech Connect (OSTI)

Purpose: To examine MRI and CT for glandular breast tissue (GBT) volume delineation and to assess interobserver variability. Methods and Materials: Fifteen breast cancer patients underwent a planning CT and MRI, consecutively, in the treatment position. Four observers (two radiation oncologists and two radiologists) delineated the GBT according to the CT and separately to the MR images. Volumes, centers of mass, maximum extensions with standard deviations (SD), and interobserver variability were quantified. Observers viewed delineation differences between MRI and CT and delineation differences among observers. Results: In cranio-lateral and cranio-medial directions, GBT volumes were delineated larger using MRI when compared with those delineated with CT. Center of mass on MRI shifted a mean (SD) 17% (4%) into the cranial direction and a mean 3% (4%) into the dorsal direction when compared with that on the planning CT. Only small variations between observers were noted. The GBT volumes were approximately 4% larger on MRI (mean [SD] ratio MRI to CT GBT volumes, 1.04 [0.06]). Findings were concordant with viewed MRI and CT images and contours. Conformity indices were only slightly different; mean conformity index was 77% (3%) for MRI and 79% (4%) for CT. Delineation differences arising from personal preferences remained recognizable irrespective of the imaging modality used. Conclusions: Contoured GBT extends substantially further into the cranio-lateral and cranio-medial directions on MRI when compared with CT. Interobserver variability is comparable for both imaging modalities. Observers should be aware of existing personal delineation preferences. Institutions are recommended to review and discuss target volume delineations and to design supplementary guidelines if necessary.

Giezen, Marina, E-mail: marinagiezen@zonnet.nl [Radiotherapy Center West, The Hague (Netherlands); Kouwenhoven, Erik [Radiotherapy Center West, The Hague (Netherlands); Scholten, Astrid N. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Coerkamp, Emile G.; Heijenbrok, Mark [Department of Radiology, Medical Center Haaglanden, The Hague (Netherlands); Jansen, Wim P.A. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Mast, Mirjam E.; Petoukhova, Anna L. [Radiotherapy Center West, The Hague (Netherlands); Struikmans, Henk [Radiotherapy Center West, The Hague (Netherlands); Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands)

2011-11-01T23:59:59.000Z

115

The MRI: A noise source of concern in the health care industry  

Science Journals Connector (OSTI)

Two recent trends in the development and use of magnetic resonance imaging (MRI) equipment have created challenges for acoustical engineers: (1) the trend toward more powerful MRI machines with greater magnetic field strengths and (2) the tendency of health care facilities to locate these machines which were previously located in basements or on grade on upper floors adjacent to (and in some cases above) other critical use areas. For newer 3?T MRI machines sound levels well over 100 dBA in the examination room are common. Along with these trends some equipment manufacturers are now providing design recommendations to address the issues of airborne and structure?borne noise within hospitals and clinics. In addition MRI manufacturers sometimes have strict requirements for acceptable levels of building vibration from other sources to prevent potential image quality problems. This paper discusses experience gained during the course of addressing MRI?generated noise on several projects. Data for airborne sound levels measured inside MRI rooms and adjacent rooms and vibration levels measured below MRI units will be presented.

2003-01-01T23:59:59.000Z

116

Imaging in population science: cardiovascular magnetic resonance in 100,000 participants of UK Biobank - rationale, challenges and approaches  

Science Journals Connector (OSTI)

Steffen E Petersen et al discuss the rationale, challenges and approaches of the large Cardiovascular Magnetic Resonance imaging study that will be part of the UK Biobank project investigating major life-threatening illnesses such as heart disease and stroke.

Steffen E Petersen; Paul M Matthews; Fabian Bamberg; David A Bluemke; Jane M Francis; Matthias G Friedrich; Paul Leeson; Eike Nagel; Sven Plein; Frank E Rademakers; Alistair A Young; Steve Garratt; Tim Peakman; Jonathan Sellors; Rory Collins; Stefan Neubauer

2013-05-28T23:59:59.000Z

117

Development of an electro-optic resonator probe for Terahertz imaging R. Mueckstein, Huiyun Liu, and O. Mitrofanov  

E-Print Network [OSTI]

Development of an electro-optic resonator probe for Terahertz imaging R. Mueckstein, Huiyun Liu, Abstract: We introduce the concept of an electro-optic resonator to improve resolution and enhance. The optimum design in terms of 3dB-bandwidth, reflectivity, and electro-optic enhancement is deduced

Haddadi, Hamed

118

Three-dimensional nuclear magnetic resonance imaging of green-state ceramics  

SciTech Connect (OSTI)

Objective is the development of nuclear magnetic resonance imaging techniques and technology applicable to the nondestructive characterization of green-state ceramics. To this end, a three-dimensional (3-D) NMR imaging technique has been developed, based on a back-projection acquisition protocol in combination with image reconstruction techniques that are based on 3-D Radon transform inversion. The method incorporates the experimental flexibility to overcome many of the difficulties associated with imaging of solid and semisolid broad-line materials, and also provides contiguously sampled data in three dimensions. This technique has been evaluated as a nondestructive characterizauon method for determining the spatial distribution of organic additves in green-state injection-molded cylindrical Si{sub 3}N{sup 4} tensile specimens. The technique has been evaluated on the basis of providing moderate image resolution over large sample volumes, high resolution over smaller specimen volumes, and sensitivity to variations in the concentration of organics. Resolution of 200{mu}m has been obtained with excellent sensitivity to concentration. A detailed account of the 3-D imaging results obtained from the study, a discussion of the difficulties and limitations of the imaging technique, and suggestions for technique and system improvements are included.

Dieckman, S.L.; Gopalsami, N.; Ford, J.M.; Raptis, A.C.; Ellingson, W.A. (Argonne National Lab., IL (United States)); Rizo, P. (CEA Centre d'Etudes Nucleaires de Grenoble, 38 (France). Lab. d'Electronique et de Technologie de l'Informatique); Tracey, D.M.; Pujari, V.K. (Norton Co., Northboro, MA (United States))

1991-09-01T23:59:59.000Z

119

Pre-Uterine Artery Embolization MRI: Beyond Fibroids  

SciTech Connect (OSTI)

Uterine leiomyomata, or fibroids, although benign, cause debilitating symptoms in many women. Symptoms are often nonspecific and may be the presenting complaint in a number of other conditions. Furthermore, because the presence of fibroids may be coincident with other symptomatic conditions that result in similar complaints, there may be diagnostic difficulty and consequent difficulty in planning therapeutic strategy. Uterine artery embolization (UAE) is a safe and effective treatment for symptomatic fibroids and is increasingly being performed. Magnetic resonance imaging (MRI) evaluation before and after treatment is routine practice with the potential to significantly alter management in up to a fifth of patients. It is well recognized that significant incidental findings may be demonstrated during imaging investigations, and in particular that abnormalities that are not directly related to the clinical question may be overlooked. Radiologists evaluating pre-UAE MRI studies must be aware of the MRI appearances of gynecological pathologies that may cause similar symptoms or that may affect the success or complication rates of UAE, and they must also be wary of 'satisfaction of search,' reviewing imaging thoroughly so that relevant other pathologies are not missed. We demonstrate the appearances of coincidental pathologies found on pre-UAE MRI, with the potential to change patient management.

Williams, Petra L., E-mail: Petra.Williams@phnt.swest.nhs.uk [Derriford Hospital, Department of Clinical Imaging (United Kingdom); Coote, Jacky M.; Watkinson, Anthony F. [Royal Devon and Exeter Foundation NHS Trust, Department of Clinical Imaging (United Kingdom)

2011-12-15T23:59:59.000Z

120

Directed evolution of a magnetic resonance imaging contrast agent for noninvasive imaging of dopamine  

E-Print Network [OSTI]

The development of molecular probes that allow in vivo imaging of neural signaling processes with high temporal and spatial resolution remains challenging. Here we applied directed evolution techniques to create magnetic ...

Shapiro, Mikhail G.

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121

The Fundamentals of Fetal MR Imaging: Part 1  

Science Journals Connector (OSTI)

Congenital malformations detected in any fetal system using ultrasound may be further evaluated with magnetic resonance imaging (MRI) to improve counseling, to plan deliveries appropriately, and sometimes to enable fetal interventions. In this first half of a 2-part review, the history and safety factors regarding fetal MRI, as well as the practical aspects of image acquisition, are discussed. In addition, as central nervous system anomalies are most commonly and best evaluated using fetal MRI, challenging central nervous system anomalies, such as fetal ventriculomegaly, posterior anomalies, and neural tube defects, detected using prenatal ultrasound are also reviewed with a focus on the fundamental implications of these diagnoses.

Matthew R. Plunk; Teresa Chapman

2014-01-01T23:59:59.000Z

122

Velocity and Concentration Studies of Flowing Suspensions by Nuclear Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Nuclear magnetic resonance imaging (NMRI) techniques were developed to study concentrated suspension flows. Some of the proposed tasks were completed and others partly completed before the funding was terminated. The tasks completed were (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The task tackled with good progress is to develop rapid imaging techniques by analog compensation of eddy currents generated by the gradient pulses and real-time image reconstruction from the rapidly obtained data. The most suitable combination of materials arrived at is pharmaceutical beads in silicon oil. Their relaxation times T, are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80-90W transmission oil flowing in a 5 cm diameter pipe. A series of distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the velocity and concentration profiles agree with the earlier lower resolution experiments. The eddy current compensation scheme works well for two channels and is being extended to eight channels including the uniform field compensation term. In addition, we have implemented a rapid reconstruction hardware that processes and displays images in a fraction of a second.

Fukushima, E.

1997-01-01T23:59:59.000Z

123

Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials and organisms  

SciTech Connect (OSTI)

Conventional nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are fundamentally challenged by the insensitivity that stems from the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This dissertation is primarily concerned with the principles and practice of optically pumped nuclear magnetic resonance (OPNMR). The enormous sensitivity enhancement afforded by optical pumping noble gases can be exploited to permit a variety of novel NMR experiments across many disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, and zero-field NMR and MRI.

Goodson, Boyd M.

1999-12-01T23:59:59.000Z

124

Numerical procedure for analyzing impurity-induced resonant-state STM images observed in high-T-c superconductors  

E-Print Network [OSTI]

Numerical procedure is developed for analyzing impurity-induced resonant-state STM images observed in high-T-c superconductors, and is applied to three sets of higher resolution data provided to us by J. C. Seamus Davis and E. W. Hudson. Each image...

Wang, Q.; Hu, Chia-Ren.

2004-01-01T23:59:59.000Z

125

MRI-based Preplanning Using CT and MRI Data Fusion in Patients With Cervical Cancer Treated With 3D-based Brachytherapy: Feasibility and Accuracy Study  

SciTech Connect (OSTI)

Purpose: Magnetic resonance imaging (MRI)-assisted radiation treatment planning enables enhanced target contouring. The purpose of this study is to analyze the feasibility and accuracy of computed tomography (CT) and MRI data fusion for MRI-based treatment planning in an institution where an MRI scanner is not available in the radiotherapy department. Methods and Materials: The registration inaccuracy of applicators and soft tissue was assessed in 42 applications with CT/MRI data fusion. The absolute positional difference of the center of the applicators was measured in four different planes from the top of the tandem to the cervix. Any inaccuracy of registration of soft tissue in relation to the position of applicators was determined and dose-volume parameters for MRI preplans and for CT/MRI fusion plans with or without target and organs at risk (OAR) adaptation were evaluated. Results: We performed 6,132 measurements in 42 CT/MRI image fusions. Median absolute difference of the center of tandem on CT and MRI was 1.1 mm. Median distance between the center of the right ovoid on CT and MRI was 1.7 and 1.9 mm in the laterolateral and anteroposterior direction, respectively. Corresponding values for the left ovoid were 1.6 and 1.8 mm. Rotation of applicators was 3.1 Degree-Sign . Median absolute difference in position of applicators in relation to soft tissue was 1.93, 1.50, 1.05, and 0.84 mm in the respective transverse planes, and 1.17, 1.28, 1.27, and 1.17 mm in selected angular directions. The dosimetric parameters for organs at risk on CT/MRI fusion plans without OAR adaptation were significantly impaired whereas the target coverage was not influenced. Planning without target adaptation led to overdosing of the target volume, especially high-risk clinical target volume - D{sub 90} 88.2 vs. 83.1 (p < 0.05). Conclusions: MRI-based preplanning with consecutive CT/MRI data fusion can be safe and feasible, with an acceptable inaccuracy of soft tissue registration.

Dolezel, Martin, E-mail: dolezelm@email.cz [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic) [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First Faculty of Medicine, Charles University, Prague (Czech Republic); Odrazka, Karel [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic) [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First Faculty of Medicine, Charles University, Prague (Czech Republic); Zizka, Jan [Department of Radiology, Charles University Teaching Hospital, Hradec Kralove (Czech Republic)] [Department of Radiology, Charles University Teaching Hospital, Hradec Kralove (Czech Republic); Vanasek, Jaroslav; Kohlova, Tereza; Kroulik, Tomas [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Spitzer, Dusan; Ryska, Pavel [Department of Radiology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Department of Radiology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Tichy, Michal; Kostal, Milan [Department of Gynaecology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Department of Gynaecology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Jalcova, Lubica [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)

2012-09-01T23:59:59.000Z

126

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

SciTech Connect (OSTI)

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

127

Abnormal Subendocardial Perfusion in Cardiac Syndrome X Detected by Cardiovascular Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

Between 10 and 20 percent of patients with typical anginal chest pain are found to have normal coronary angiograms. A subgroup of these patients, who also have classic downsloping ST-segment depression on exercise testing, are classified as having cardiac syndrome X. The exact pathophysiological... Patients with cardiac syndrome X have angina and abnormal exercise-test results but normal findings on coronary angiography. Although myocardial ischemia has been suspected to be the cause, this has been difficult to document. In this study, myocardial-perfusion magnetic resonance imaging demonstrated abnormal subendocardial perfusion during adenosine infusion in 20 patients with the syndrome.

Panting J.R.; Gatehouse P.D.; Yang G.-Z.

2002-06-20T23:59:59.000Z

128

Velocity and Concentration Studies of Flowing Suspensions by Nuclear Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Nuclear magnetic resonance imaging (NMRI) techniques were developed to study concentrated suspension flows. Some of the proposed tasks were completed and others partly completed before the funding was terminated. The tasks completed were (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The task tackled with good progress is to develop rapid imaging techniques by analog compensation of eddy currents generated by the gradient pulses and real-time image reconstruction from the rapidly obtained data. The most suitable combination of materials arrived at is pharmaceutical beads in silicon oil. Their relaxation times T, are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80-90W transmission oil flowing in a 5 cm diameter pipe. A series of distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the velocity and concentration profiles agree with the earlier lower resolution experiments.

Fukushima, E.

1997-04-01T23:59:59.000Z

129

2-3 High Field Magnetic Resonance Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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)

130

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

SciTech Connect (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

131

Use of Superparamagnetic Nanoparticle/Block Copolymer Electrostatic Complexes as Contrast Agents in Magnetic Resonance Imaging  

E-Print Network [OSTI]

During the past years we have investigated the complexation between nanocolloids and oppositely charged polymers. The nanocolloids examined were ionic surfactant micelles and inorganic oxide nanoparticles. For the polymers, we used homopolyelectrolytes and block copolymers with linear and comb architectures. In general, the attractive interactions between oppositely charged species are strong and as such, the simple mixing of solutions containing dispersed constituents yield to a precipitation, or to a phase separation. We have developed means to control the electrostatically-driven attractions and to preserve the stability of the mixed solution. With these approaches, we designed novel core-shell nanostructures, e.g. as those obtained with polymers and iron oxide superparamagnetic nanoparticles. In this presentation, we show that electrostatic complexation can be used to tailor new functionalized nanoparticles and we provide examples related to biomedical applications in the domain of contrast agents for Magnetic Resonance Imaging.

Jean-Francois Berret; Regis Cartier

2007-01-26T23:59:59.000Z

132

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

133

Magnetoacoustic tomography with magnetic induction for high-resolution bioimepedance imaging through vector source reconstruction under the static field of MRI magnet  

SciTech Connect (OSTI)

Purpose: Magnetoacoustic tomography with magnetic induction (MAT-MI) is an imaging modality to reconstruct the electrical conductivity of biological tissue based on the acoustic measurements of Lorentz force induced tissue vibration. This study presents the feasibility of the authors' new MAT-MI system and vector source imaging algorithm to perform a complete reconstruction of the conductivity distribution of real biological tissues with ultrasound spatial resolution. Methods: In the present study, using ultrasound beamformation, imaging point spread functions are designed to reconstruct the induced vector source in the object which is used to estimate the object conductivity distribution. Both numerical studies and phantom experiments are performed to demonstrate the merits of the proposed method. Also, through the numerical simulations, the full width half maximum of the imaging point spread function is calculated to estimate of the spatial resolution. The tissue phantom experiments are performed with a MAT-MI imaging system in the static field of a 9.4 T magnetic resonance imaging magnet. Results: The image reconstruction through vector beamformation in the numerical and experimental studies gives a reliable estimate of the conductivity distribution in the object with a ?1.5 mm spatial resolution corresponding to the imaging system frequency of 500 kHz ultrasound. In addition, the experiment results suggest that MAT-MI under high static magnetic field environment is able to reconstruct images of tissue-mimicking gel phantoms and real tissue samples with reliable conductivity contrast. Conclusions: The results demonstrate that MAT-MI is able to image the electrical conductivity properties of biological tissues with better than 2 mm spatial resolution at 500 kHz, and the imaging with MAT-MI under a high static magnetic field environment is able to provide improved imaging contrast for biological tissue conductivity reconstruction.

Mariappan, Leo; Hu, Gang [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 (United States)] [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 (United States); He, Bin, E-mail: binhe@umn.edu [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 and Institute of Engineering in Medicine, University of Minnesota, Minnesota 55455 (United States)] [Department of Biomedical Engineering, University of Minnesota, Minnesota 55455 and Institute of Engineering in Medicine, University of Minnesota, Minnesota 55455 (United States)

2014-02-15T23:59:59.000Z

134

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

135

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

136

Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.  

SciTech Connect (OSTI)

The production and aging of silicone materials remains an important issue in the weapons stockpile due to their utilization in a wide variety of components and systems within the stockpile. Changes in the physical characteristics of silicone materials due to long term desiccation has been identified as one of the major aging effects observed in silicone pad components. Here we report relaxation nuclear magnetic resonance imaging (R-NMRI) spectroscopy characterization of the silica-filled and unfilled polydimethylsiloxane (PDMS) and polydiphenylsiloxane (PDPS) copolymer (M9787) silicone pads within desiccating environments. These studies were directed at providing additional details about the heterogeneity of the desiccation process. Uniform NMR spin-spin relaxation time (T2) images were observed across the pad thickness indicating that the drying process is approximately uniform, and that the desiccation of the M9787 silicone pad is not a H2O diffusion limited process. In a P2O5 desiccation environment, significant reduction of T2 was observed for the silica-filled and unfilled M9787 silicone pad for desiccation up to 225 days. A very small reduction in T2 was observed for the unfilled copolymer between 225 and 487 days. The increase in relative stiffness with desiccation was found to be higher for the unfilled copolymer. These R-NMRI results are correlated to local changes in the modulus of the material

Alam, Todd M; Cherry, Brian Ray; Alam, Mary Kathleen

2004-06-01T23:59:59.000Z

137

MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization  

SciTech Connect (OSTI)

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

138

Capture and evolution of dust in planetary mean-motion resonances: a fast, semi-analytic method for generating resonantly trapped disk images  

E-Print Network [OSTI]

Dust grains migrating under Poynting-Robertson drag may be trapped in mean-motion resonances with planets. Such resonantly trapped grains are observed in the solar system. In extrasolar systems, the exozodiacal light produced by dust grains is expected to be a major obstacle to future missions attempting to directly image terrestrial planets. The patterns made by resonantly trapped dust, however, can be used to infer the presence of planets, and the properties of those planets, if the capture and evolution of the grains can be modelled. This has been done with N-body methods, but such methods are computationally expensive, limiting their usefulness when considering large, slowly evolving grains, and for extrasolar systems with unknown planets and parent bodies, where the possible parameter space for investigation is large. In this work, we present a semi-analytic method for calculating the capture and evolution of dust grains in resonance, which can be orders of magnitude faster than N-body methods. We calibr...

Shannon, Andrew; Wyatt, Mark

2015-01-01T23:59:59.000Z

139

Three-dimensional liver motion tracking using real-time two-dimensional MRI  

SciTech Connect (OSTI)

Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal, and coronal 2D MRI series yielded 3D respiratory motion curves for all volunteers. The motion directionality and amplitude were very similar when measured directly as in-plane motion or estimated indirectly as through-plane motion. The mean peak-to-peak breathing amplitude was 1.6 mm (left-right), 11.0 mm (craniocaudal), and 2.5 mm (anterior-posterior). The position of the watermelon structure was estimated in 2D MRI images with a root-mean-square error of 0.52 mm (in-plane) and 0.87 mm (through-plane). Conclusions: A method for 3D tracking in 2D MRI series was developed and demonstrated for liver tracking in volunteers. The method would allow real-time 3D localization with integrated MR-Linac systems.

Brix, Lau, E-mail: lau.brix@stab.rm.dk [Department of Procurement and Clinical Engineering, Region Midt, Olof Palmes Allé 15, 8200 Aarhus N, Denmark and MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark)] [Department of Procurement and Clinical Engineering, Region Midt, Olof Palmes Allé 15, 8200 Aarhus N, Denmark and MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Ringgaard, Steffen [MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark)] [MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, Aabogade 34, 8200 Aarhus N, Denmark and Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark)] [Department of Computer Science, Aarhus University, Aabogade 34, 8200 Aarhus N, Denmark and Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Poulsen, Per Rugaard [Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark and Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark)] [Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark and Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark)

2014-04-15T23:59:59.000Z

140

Femtosecond Single-Shot Imaging of Nanoscale Ferromagnetic Order in Co/Pd Multilayers using Resonant X-ray Holography  

SciTech Connect (OSTI)

We present the first single-shot images of ferromagnetic, nanoscale spin order taken with femtosecond x-ray pulses. X-ray-induced electron and spin dynamics can be outrun with pulses shorter than 80 fs in the investigated fluence regime, and no permanent aftereffects in the samples are observed below a fluence of 25 mJ/cm{sup 2}. Employing resonant spatially-muliplexed x-ray holography results in a low imaging threshold of 5 mJ/cm{sup 2}. Our results open new ways to combine ultrafast laser spectroscopy with sequential snapshot imaging on a single sample, generating a movie of excited state dynamics.

Wang, Tianhan; Zhu, Diling; Benny Wu,; Graves, Catherine; Schaffert, Stefan; Rander, Torbjorn; Muller, leonard; Vodungbo, Boris; Baumier, Cedric; Bernstein, David P.; Brauer, Bjorn; Cros, Vincent; Jong, Sanne de; Delaunay, Renaud; Fognini, Andreas; Kukreja, Roopali; Lee, Sooheyong; Lopez-Flores, Victor; Mohanty, Jyoti; Pfau, Bastian; Popescu, 5 Horia

2012-05-15T23:59:59.000Z

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

Magnetic resonance elastography  

Science Journals Connector (OSTI)

The goal of our research is to develop MRI?based methods for assessing the mechanical properties of tissues in vivo. We have focused on a novel MRI technique for visualizing propagating acoustic shear waves [Science 269 1854–1857 (1995)]. Suitable dynamic shear stress for Magnetic Resonance Elastography (MRE) can be generated by surface drivers inertial effects acoustic radiation pressure or endogenous physiologic mechanisms. The MRE acquisition sequence is capable of visualizing cyclic tissue motion of less than 1 micron in displacement amplitude with imaging times ranging from 100 ms to several minutes. Inversion algorithms based on continuum mechanics are used to process the acquired data to generate maps of mechanical properties such as depict stiffness viscosity attenuation and anisotropic behavior. We have applied MRE to assess specimens of a variety of tissues ranging in stiffness from lung to cartilage. Human studies have demonstrated that it is feasible to apply MRE to quantitatively image the mechanical properties of skeletal muscles gray and white matter in the brain thyroid kidney liver and skin. Our preliminary clinical studies have to date applied MRE to observe changes in tissue mechanical properties in patients with breast brain and thyroid tumors liver fibrosis and diffuse diseases of skeletal muscle.

2005-01-01T23:59:59.000Z

142

Molecular imaging of water binding state and diffusion in breast cancer using diffuse optical spectroscopy and diffusion weighted MRI  

E-Print Network [OSTI]

Molecular imaging of water binding state and diffusion inChung et al. , “In vivo water state measurements in breastby measuring tis- sue water state using diffuse optical

Chung, So Hyun; Yu, Hon; Su, Min-Ying; Cerussi, Albert E.; Tromberg, Bruce J.

2012-01-01T23:59:59.000Z

143

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

Office of Science (SC) Website

benefit to spin-off field: Static & dynamic imaging of lungs, heart, and possibly the brain, possible imaging of astronauts 'Hyperpolarized gas imaging External link ', a new...

144

Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals: Evidence of image potential resonance and pseudogap  

SciTech Connect (OSTI)

We study the unoccupied region of the electronic structure of the fivefold symmetric surface of an icosahedral (i) Al-Pd-Mn quasicrystal. A feature that exhibits parabolic dispersion with an effective mass of (1.15±0.1)me and tracks the change in the work function is assigned to an image potential resonance because our density functional calculation shows an absence of band gap in the respective energy region. We show that Sn grows pseudomorphically on i?Al?Pd?Mn as predicted by density functional theory calculations, and the energy of the image potential resonance tracks the change in the work function with Sn coverage. The image potential resonance appears much weaker in the spectrum from the related crystalline Al-Pd-Mn surface, demonstrating that its strength is related to the compatibility of the quasiperiodic wave functions in i?Al?Pd?Mn with the free-electron-like image potential states. Our investigation of the energy region immediately above EF provides unambiguous evidence for the presence of a pseudogap, in agreement with our density functional theory calculations.

Maniraj, M [UGC-DAE Confortium for Scientific Research; Rai, Abhishek [UGC-DAE Confortium for Scientific Research; Barman, S R [UGC-DAE Confortium for Scientific Research; Krajci, M [Slovak Academy of Sciences; Schlagel, Deborah L [Ames Laboratory; Lograsso, Thomas A [Ames Laboratory; Horn, K [Fritz-Haber-Institut der Max-Planck-Gesellschaft

2014-09-01T23:59:59.000Z

145

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

146

Automatic Landmarking of Magnetic Resonance brain Images Camille Izard*a,b, Bruno M. Jedynaka,b and Craig E.L. Starkc  

E-Print Network [OSTI]

Automatic Landmarking of Magnetic Resonance brain Images Camille Izard*a,b, Bruno M. JedynakaDepartment of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD ABSTRACT Landmarking MR images is crucial in registering brain structures from different images. It consists in locating the voxel

Jedynak, Bruno M.

147

In vivo magnetic resonance vascular imaging using laser-polarized 3He microbubbles  

Science Journals Connector (OSTI)

...because of its larger magnetic moment...filled to ?2 atmosphere. Two cubic centimeters of gas (at 1 atmosphere = 101.3 kPa...Squibb) and two plasma volume expanders...both small and large diameter counting...operating at 65.1 MHz and 85.5 MHz...3 He to target areas for MRI. 1 Happer...

Mark S. Chawla; X. Josette Chen; Harald E. Möller; Gary P. Cofer; C. Ted Wheeler; Laurence W. Hedlund; G. Allan Johnson

1998-01-01T23:59:59.000Z

148

Discovering effective connectivity among brain regions from functional MRI data  

Science Journals Connector (OSTI)

Functional magnetic resonance imaging (fMRI) data have been used for identifying brain regions that activate when a subject is presented a stimulus or performs a task. Beyond identifying which regions of the brain are active during a task, it is also of interest to discover causal relationships among activity in those regions, that is, which regions of the brain influence, which other regions of the brain during a task. Two algorithms for causal discovery were applied to fMRI data, the greedy equivalence search (GES) algorithm and the independent multiple-sample greedy equivalence search (iMAGES). GES applies to individual datasets, and iMAGES to multiple datasets. We consider the stability of the GES results across subjects and experimental repetitions with the same subject. We find that some iMAGES connections agree with previous knowledge of the functional roles of the brain regions. The strengths and limitations of the research work and opportunities for future work are also discussed.

Carlos A. Perez; Eman M. El-Sheikh; Clark Glymour

2010-01-01T23:59:59.000Z

149

Electron Paramagnetic Resonance Oxygen Image Hypoxic Fraction Plus Radiation Dose Strongly Correlates With Tumor Cure in FSa Fibrosarcomas  

SciTech Connect (OSTI)

Purpose: Tumor hypoxia has long been known to produce resistance to radiation. In this study, electron paramagnetic resonance (EPR) oxygen imaging was investigated for its power to predict the success of tumor control according to tumor oxygenation level and radiation dose. Methods and Materials: A total of 34 EPR oxygen images were obtained from the legs of C3H mice bearing 0.5-cm{sup 3} FSa fibrosarcomas under both normal (air breathing) and clamped tumor conditions. Under the same conditions as those during which the images were obtained, the tumors were irradiated to a variety of doses near the FSa dose at which 50% of tumors were cured. Tumor tissue was distinguished from normal tissue using co-registration of the EPR oxygen images with spin-echo magnetic resonance imaging of the tumor and/or stereotactic localization. The tumor voxel statistics in the EPR oxygen image included the mean and median partial pressure of oxygen and the fraction of tumor voxels below the specified partial pressure of oxygen values of 3, 6, and 10 mm Hg. Bivariate logistic regression analysis using the radiation dose and each of the EPR oxygen image statistics to determine which best separated treatment failure from success. Results: The measurements of the dose at which 50% of tumors were cured were similar to those found in published data for this syngeneic tumor. Bivariate analysis of 34 tumors demonstrated that tumor cure correlated with dose (p = 0.004) and with a <10 mm Hg hypoxic fraction (p = 0.023). Conclusion: Our results have shown that, together, radiation dose and EPR image hypoxic fraction separate the population of FSa fibrosarcomas that are cured from those that fail, thus predicting curability.

Elas, Martyna [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL (United States); Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, University of Chicago, Chicago, IL (United States); Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow (Poland); Bell, Rebecca; Hleihel, Danielle; Barth, Eugene D.; McFaul, Colin [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL (United States); Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, University of Chicago, Chicago, IL (United States); Haney, Chad R. [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL (United States); Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, University of Chicago, Chicago, IL (United States); Department of Radiology, University of Chicago Pritzker School of Medicine, Chicago, IL (United States); Bielanska, Joanna; Pustelny, Katarzyna [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL (United States); Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, University of Chicago, Chicago, IL (United States); Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow (Poland); Ahn, Kang-Hyun [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL (United States); Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, University of Chicago, Chicago, IL (United States)] (and others)

2008-06-01T23:59:59.000Z

150

Application of topological sensitivity toward tissue elasticity imaging using magnetic resonance data  

E-Print Network [OSTI]

) and brain degeneration imaging (Green et al., 2008) with promising results. Specifically, the MRE estimates

Guzina, Bojan

151

Velocity and concentration studies of flowing suspensions by nuclear magnetic resonance imaging. Final report, October 7, 1994--October 6, 1996  

SciTech Connect (OSTI)

Nuclear magnetic resonance imaging techniques were developed to study concentrated suspension flows. The tasks completed were: (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The partially completed task is the development of rapid imaging techniques by analog compensation of eddy currents, generated by the gradient pulses, and real-time image reconstruction from the data. The best combination of materials found is pharmaceutical beads in silicon oil. Their relaxation times T{sub 1} are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80--90W transmission oil flowing in a 5 cm diameter pipe. Distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the concentration and velocity profiles agree with earlier lower resolution experiments. The eddy current compensation scheme works well for two channels and is being extended to eight channels. The authors have also built a rapid reconstruction hardware that processes and displays images in a fraction of a second. They studied the flow of neutrally buoyant concentrated suspension past a step expansion and contraction in a cylindrical pipe. Interesting transition is observed at the expansion whereby the high fluids-fraction outer layer spreads to become the outer layer in the larger pipe.

NONE

1996-12-31T23:59:59.000Z

152

Neutron Imaging Explored as Complementary Technique for Improving Cancer  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

153

Advanced Magnetic Resonance Imaging of the Physical Processes in Human Glioblastoma  

Science Journals Connector (OSTI)

...tumor angiogenesis.Magn Reson Med 1998;40:793-9. 69. Einstein A . [uber die von der molekularkinetischen Theorie der Warme geforderte Bewegung von in ruhenden Flussigkeiten suspendierten Teilchen].Annalen der Physik 1905;322:549-60. 70...

Jayashree Kalpathy-Cramer; Elizabeth R. Gerstner; Kyrre E. Emblem; Ovidiu C. Andronesi; Bruce Rosen

2014-09-01T23:59:59.000Z

154

Nano-mechanical tuning and imaging of a photonic crystal micro-cavity resonance  

Science Journals Connector (OSTI)

We show that nano-mechanical interaction using atomic force microscopy (AFM) can be used to map out mode-patterns of an optical micro-resonator with high spatial accuracy....

Hopman, W C L; van der Werf, K O; Hollink, A J F; Bogaerts, W; Subramaniam, V; de Ridder, R M

2006-01-01T23:59:59.000Z

155

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.

156

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.

157

Nanoscale Imaging with Resonant Coherent X Rays: Extension of Multiple-Wavelength Anomalous Diffraction to Nonperiodic Structures  

Science Journals Connector (OSTI)

The methodology of multiple-wavelength anomalous diffraction, widely used for macromolecular structure determination, is extended to the imaging of nonperiodic nanostructures. We demonstrate the solution of the phase problem by a combination of two resonantly recorded coherent scattering patterns at the carbon K edge (285 eV). Our approach merges iterative phase retrieval and x-ray holography approaches, yielding unique and rapid reconstructions. The element, chemical, and magnetic state specificity of our method further renders it widely applicable to a broad range of nanostructures, providing a spatial resolution that is limited, in principle, by wavelength only.

A. Scherz; D. Zhu; R. Rick; W. F. Schlotter; S. Roy; J. Lüning; J. Stöhr

2008-08-13T23:59:59.000Z

158

Near-resonant spatial images of confined Bose-Einstein condensates in a 4-Dee magnetic bottle  

Science Journals Connector (OSTI)

We present quantitative measurements of the spatial density profile of Bose-Einstein condensates of sodium atoms confined in a 4-Dee magnetic bottle. The condensates are imaged in transmission with near-resonant laser light. We demonstrate that the Thomas-Fermi surface of a condensate can be determined to better than 1%. More generally, we obtain excellent agreement with mean-field theory. We conclude that precision measurements of atomic scattering lengths and interactions between phase-separated cold atoms in a harmonic trap can be performed with high precision using this method.

Lene Vestergaard Hau; B. D. Busch; Chien Liu; Zachary Dutton; Michael M. Burns; J. A. Golovchenko

1998-07-01T23:59:59.000Z

159

Magnetic resonance imaging of the left atrial appendage post pulmonary vein isolation: Implications for percutaneous left atrial appendage occlusion  

Science Journals Connector (OSTI)

AbstractBackground There is increasing interest in performing left atrial appendage (LAA) occlusion at the time of atrial fibrillation (AF) ablation procedures. However, to date there has been no description of the acute changes to the LAA immediately following pulmonary vein (PV) isolation and additional left atrium (LA) substrate modification. This study assessed changes in the size and tissue characteristics of the LAA ostium in patients undergoing PV isolation. Methods This series included 8 patients who underwent cardiovascular magnetic resonance evaluation of the LA with delayed enhancement magnetic resonance imaging and contrast enhanced 3-D magnetic resonance angiography pre-, within 48 h of, and 3 months post ablation. Two independent cardiac radiologists evaluated the ostial LAA diameters and area at each time point in addition to the presence of gadolinium enhancement. Results Compared to pre-ablation values, the respective median differences in oblique diameters and LAA area were +1.8 mm, +1.7 mm, and +0.6 cm2 immediately post ablation (all NS) and ?2.7 mm, ?2.3 mm, and ?0.5 cm2 at 3 months (all NS). No delayed enhancement was detected in the LAA post ablation. Conclusion No significant change to LAA diameter, area, or tissue characteristics was noted after PV isolation. While these findings suggest the safety and feasibility of concomitant PV isolation and LAA device occlusion, the variability in the degree and direction of change of the LAA measurements highlights the need for further study.

Sheldon M. Singh; Laura Jimenez-Juan; Asaf Danon; Gorka Bastarrika; Andriy V. Shmatukha; Graham A. Wright; Eugene Crystal

2014-01-01T23:59:59.000Z

160

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

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.


161

A Multimodal Nanoparticle for Preoperative Magnetic Resonance Imaging and Intraoperative Optical Brain Tumor Delineation  

Science Journals Connector (OSTI)

...humidified 5% CO2 atmosphere in DMEM supplemented...resonating at 200 MHz. Multiple slice...CO). The area of each region...not seen with larger magnetic particles...Methods). The areas obtained from...estimation of tumor area by Cy5.5 fluorescence...they are too large to undergo renal...do not bind plasma proteins and...

Moritz F. Kircher; Umar Mahmood; Raymond S. King; Ralph Weissleder; and Lee Josephson

2003-12-01T23:59:59.000Z

162

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution conductivity imaging  

E-Print Network [OSTI]

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution potentials and the magnetic fields produced by the probing current are measured. Surface potentials are measured by using conventional electrical impedance tomography techniques and high resolution magnetic

Eyüboðlu, Murat

163

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

164

Portable MRI and 129Xe Signal Amplification by Gas Extraction  

E-Print Network [OSTI]

by nuclear magnetic resonance. Science, [24] E. Danieli, J.magnetic resonance hyperpolarized biosensor. Science, 314(Magnetic Reso- nance Imaging in a Fraction of a Second. Science,

Graziani, Dominic Michael

2011-01-01T23:59:59.000Z

165

Chapter Twenty One - Rabies Diagnosis: MR Imaging  

Science Journals Connector (OSTI)

In vivo magnetic resonance imaging (MRI) techniques provide clues for the differential diagnosis of rabies and other encephalitides. Clinical status of the subjects, conscious or comatose, must be taken into account. Blood brain barrier (BBB) integrity and lesional extent can vary accordingly. Subtle brain MR abnormalities in symmetrical distribution, however, preclude its use as a confirmatory diagnostic test. Quantitative advanced MRI techniques, such as voxel-based morphometric diffusion tensor imaging (DTI) based on whole-brain probabilistic tractography maps in assessing mean diffusivity (MD), and fractional anisotropy (FA) values, have been introduced to study evolving disease processes, particularly during the non-comatose phase. Iron imaging of the brain, albeit conventionally used for detecting hemorrhage, may be potentially useful in tracking inflammatory reactions.

Jiraporn Laothamatas; Witaya Sungkarat; Thiravat Hemachudha

2014-01-01T23:59:59.000Z

166

Cost Effective Open Geometry HTS MRI System amended to BSCCO 2212 Wire for High Field Magnets  

SciTech Connect (OSTI)

The original goal of this Phase II Superconductivity Partnership Initiative project was to build and operate a prototype Magnetic Resonance Imaging (MRI) system using high temperature superconductor (HTS) coils wound from continuously processed dip-coated BSCCO 2212 tape conductor. Using dip-coated tape, the plan was for MRI magnet coils to be wound to fit an established commercial open geometry, 0.2 Tesla permanent magnet system. New electronics and imaging software for a prototype higher field superconducting system would have added significantly to the cost. However, the use of the 0.2 T platform would allow the technical feasibility and the cost issues for HTS systems to be fully established. Also it would establish the energy efficiency and savings of HTS open MRI compared with resistive and permanent magnet systems. The commercial goal was an open geometry HTS MRI running at 0.5 T and 20 K. This low field open magnet was using resistive normal metal conductor and its heat loss was rather high around 15 kolwatts. It was expected that an HTS magnet would dissipate around 1 watt, significantly reduce power consumption. The SPI team assembled to achieve this goal was led by Oxford Instruments, Superconducting Technology (OST), who developed the method of producing commercial dip coated tape. Superconductive Components Inc. (SCI), a leading US supplier of HTS powders, supported the conductor optimization through powder optimization, scaling, and cost reduction. Oxford Magnet Technology (OMT), a joint venture between Oxford Instruments and Siemens and the world’s leading supplier of MRI magnet systems, was involved to design and build the HTS MRI magnet and cryogenics. Siemens Magnetic Resonance Division, a leading developer and supplier of complete MRI imaging systems, was expected to integrate the final system and perform imaging trials. The original MRI demonstration project was ended in July 2004 by mutual consent of Oxford Instruments and Siemens. Between the project start and that date a substantial shift in the MRI marketplace occurred, with rapid growth for systems at higher fields (1.5 T and above) and a consequent decline in the low field market (<1.0 T). While the project aim appeared technically attainable at that time, the conclusion was reached that the system and market economics do not warrant additional investment. The program was redirected to develop BSCCO 2212 multifilament wire development for high field superconducting magnets for NMR and other scientific research upon an agreement between DOE and Oxford Instruments, Superconducting Technology. The work t took place between September, 2004 and the project end in early 2006 was focused on 2212 multifilamentary wire. This report summarizes the technical achievements both in 2212 dip coated for an HTS MRI system and in BSCCO 2212 multifilamentary wire for high field magnets.

Kennth Marken

2006-08-11T23:59:59.000Z

167

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

168

Geometric accuracy of 3D coordinates of the Leksell stereotactic skull frame in 1.5 Tesla- and 3.0 Tesla-magnetic resonance imaging: a comparison of three different fixation screw materials  

Science Journals Connector (OSTI)

......In addition, spatial accuracy over the entire brain is necessary when multiple metastatic brain tumors are being treated. Regarding image distortion...magnetic resonance imaging for postimplantation deep brain stimulator lead localization. Neurosurgery......

Hisato Nakazawa; Yoshimasa Mori; Osamu Yamamuro; Masataka Komori; Yuta Shibamoto; Yukio Uchiyama; Takahiko Tsugawa; Masahiro Hagiwara

2014-11-01T23:59:59.000Z

169

A 16-Channel Receive Array Insert for Magnetic Resonance Imaging of the Breast at 7T  

E-Print Network [OSTI]

of the second scan divided by the standard deviation of a region in the noise-only image. ..................................................... 36 Figure 4.3. SNR maps of a homogenous canola oil phantom acquired with the volume coil (left) and the 16... for the coupling patterns in the individual receive element field patterns. ................................................................................................................ 49 Figure 5.1: Visible and thermal images of a breast canola oil phantom...

By, Samantha

2014-04-01T23:59:59.000Z

170

Potential hazards and artifacts of ferromagnetic and nonferromagnetic surgical and dental materials and devices in nuclear magnetic resonance imaging  

SciTech Connect (OSTI)

The risks to patients with metal surgical implants who are undergoing nuclear magnetic resonance (NMR) imaging and the artifacts caused by such implants were studied. Twenty-one aneurysm and other hemostatic clips and a variety of other materials (e.g., dental amalgam, 14 karat gold) were used. Longitudinal forces and torques were found to be exerted upon 16 of the 21 clips. With five aneurysm clips, forces and torques sufficient to produce risk of hemorrhage from dislocation of the clip from the vessel or aneurysm, or cerebral injury by clip displacement without dislodgement were identified. The induced ferromagnetism was shown to be related to the composition of the alloys from which the clips were manufactured. Clips with 10-14% nickel are evidently without sufficient induced ferromagnetism to cause hazard. The extent of NMR imaging artifacts was greater for materials with measurable ferromagnetic properties, but metals without measurable ferromagnetism in our tests also resulted in significant artifacts. Dental amalgam and 14 karat gold produced no imaging artifacts, but stainless steels in dentures and orthodontic braces produced extensive artifacts in the facial region.

New, P.F.J. (Massachusetts General Hospital, Boston, MA); Rosen, B.R.; Brady, T.J.; Buonanno, F.S.; Kistler, J.P.; Burt, C.T.; Hinshaw, W.S.; Newhouse, J.H.; Pohost, G.M.; Taveras, J.M.

1983-04-01T23:59:59.000Z

171

Electron nuclear double resonance study of photostimulated luminescence active centers in CsBr:Eu{sup 2+} medical imaging plates  

SciTech Connect (OSTI)

CsBr:Eu{sup 2+} needle image plates exhibit an electron-paramagnetic-resonance (EPR) spectrum at room temperature (RT), whose intensity is correlated with the photostimulated luminescence sensitivity of the plate. This EPR spectrum shows a strong temperature dependence: At RT it is owing to a single Eu{sup 2+} (S =7/2) center with axial symmetry, whereas at T<35 K the spectra can only be explained when two distinct centers are assumed to be present, a minority axial center and a majority center with nearly extremely rhombic symmetry. In this paper these low-temperature centers are studied with electron nuclear double resonance (ENDOR) spectroscopy, which reveals the presence of {sup 1}H nuclei close to the central Eu{sup 2+} ions in the centers. Analysis of the angular dependence of the ENDOR spectra allows to propose models for these centers, providing an explanation for the observed difference in intensity between the spectral components and for their temperature dependence.

Vrielinck, H.; Loncke, F.; Matthys, P.; Callens, F. [Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, B-9000 Gent (Belgium); Tahon, J.-P.; Leblans, P. [Agfa HealthCare NV, Septestraat 27, B-2640 Mortsel (Belgium)

2011-02-01T23:59:59.000Z

172

MRI Study on Maple Syrup Urine Disease via the LONI Pipeline With the creation of large image datasets for quantitative disease classification and diagnosis, like the Alzheimer's Disease  

E-Print Network [OSTI]

MRI Study on Maple Syrup Urine Disease via the LONI Pipeline Overview: With the creation of large pipeline implementation. Given this need, software tools like STAMPS (http://www.ncbi.nlm.nih.gov/pubmed/19346025) and the LONI Pipeline (http://pipeline.loni.ucla.edu/) were developed. These tools integrate

Bjørnstad, Ottar Nordal

173

Hart AG, Bowtell RW, Kckenberger W, Wenseleers T, Ratnieks FLW. 2003. Magnetic resonance imaging in entomology: a critical review. 9pp. Journal of Insect Science, 3:5, Available online: insectscience.org/3.5  

E-Print Network [OSTI]

.5 Journal of Insect Science insectscience.org Magnetic resonance imaging in entomology: a critical reviewHart AG, Bowtell RW, Köckenberger W, Wenseleers T, Ratnieks FLW. 2003. Magnetic resonance imaging in entomology: a critical review. 9pp. Journal of Insect Science, 3:5, Available online: insectscience.org/3

Wenseleers, Tom

174

Advanced Magnetic Resonance Imaging of the Physical Processes in Human Glioblastoma  

Science Journals Connector (OSTI)

...disease. Application of MR Physics to Glioblastoma In most clinical...series of images of the first-pass passage of the CA through the...signal recorded during the first pass of the CA depends on the architecture...In brief, a relaxation rate curve (deltaR2*) proportional...

Jayashree Kalpathy-Cramer; Elizabeth R. Gerstner; Kyrre E. Emblem; Ovidiu C. Andronesi; and Bruce Rosen

2014-09-01T23:59:59.000Z

175

Electron Paramagnetic Resonance Oxygen Images Correlate Spatially and Quantitatively with Oxylite Oxygen Measurements  

Science Journals Connector (OSTI)

...72-5. 39 Chen Y, Xiong T, Yu L, Zeng S, Luo Q. Whole-body fluorescent optical imaging based on power light emitting diode. Conf Proc IEEE Eng Med Biol Soc 2005;2:1442-5. 40 Xiong T, Zhang Z, Liu BF, et al. In vivo optical...

Martyna Elas; Kang-Hyun Ahn; Adrian Parasca; Eugene D. Barth; David Lee; Chad Haney; Howard J. Halpern

2006-07-15T23:59:59.000Z

176

A systematic review and meta-analysis of the fMRI investigation of autism spectrum disorders  

Science Journals Connector (OSTI)

Recent years have seen a rapid increase in the investigation of autism spectrum disorders (ASD) through the use of functional magnetic resonance imaging (fMRI). We carried out a systematic review and ALE meta-analysis of fMRI studies of ASD. A disturbance to the function of social brain regions is among the most well replicated finding. Differences in social brain activation may relate to a lack of preference for social stimuli as opposed to a primary dysfunction of these regions. Increasing evidence points towards a lack of effective integration of distributed functional brain regions and disruptions in the subtle modulation of brain function in relation to changing task demands in ASD. Limitations of the literature to date include the use of small sample sizes and the restriction of investigation to primarily high functioning males with autism.

Ruth C.M. Philip; Maria R. Dauvermann; Heather C. Whalley; Katie Baynham; Stephen M. Lawrie; Andrew C. Stanfield

2012-01-01T23:59:59.000Z

177

MRI in Experimental Stroke Timothy Q. Duong  

E-Print Network [OSTI]

Chapter 24 MRI in Experimental Stroke Timothy Q. Duong Abstract Stroke is the third leading cause experimental stroke models and stroke patients have shown that there is often a gradual progression minutes after onsets, whereas computed tomography and other imaging modalities fail to detect stroke

Duong, Timothy Q.

178

Design of multi-channel radio-frequency front-end for 200mhz parallel magnetic resonance imaging  

E-Print Network [OSTI]

increases to 64 or even 128, the traditional method of stacking the same number of radio-frequency (RF) receivers with very low level of integration becomes expensive and cumbersome. However, the cost, size, power consumption of the Parallel MRI receivers...

Liu, Xiaoqun

2009-05-15T23:59:59.000Z

179

Influence of open and sealed fractures on fluid flow and water saturation in sandstone cores using Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

......problems in hydrocarbon production or the safe deep storage of high-level waste. 2 Principles of nmr and mri techniques Nuclear...obtained by coring at surface exposure subject to long-term interaction with the atmosphere, and are hence......

S. Baraka-Lokmane; G. Teutsch; I. G. Main

2001-11-01T23:59:59.000Z

180

Global analysis of Fo rster resonance energy transfer in live cells measured by fluorescence lifetime imaging microscopy exploiting  

E-Print Network [OSTI]

Global analysis of Fo¨ rster resonance energy transfer in live cells measured by fluorescence of Fo¨ rster resonance energy transfer (FRET) in live cells using the rise time of acceptor fluorescence those molecules that are involved in the energy-transfer process are monitored. This contrasts

van Stokkum, Ivo

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

Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

The diagnosis of diastolic heart failure requires a combination of clinical, laboratory, and technical findings, providing evidence of the existence of heart failure, the absence of (significant) systolic abno...

Frank E. Rademakers MD; PhD; Jan Bogaert MD; PhD

2008-01-01T23:59:59.000Z

182

E-Print Network 3.0 - access mri system Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

search results for: access mri system Page: << < 1 2 3 4 5 > >> 1 NeuroImage Human Brain Mapping 2000 Meeting Poster No.: 916 Summary: NeuroImage Human Brain Mapping 2000...

183

RSNA 2002: Image Fusion Image Fusion  

E-Print Network [OSTI]

of anatomical feature #12;RSNA 2002: Image Fusion Types of Data to be Registered Anatomic CT, MRI, US DigitizedRSNA 2002: Image Fusion Image Fusion: Introduction to the Technology Charles A. Pelizzari, Ph.D. Department of Radiation and Cellular Oncology The University of Chicago #12;RSNA 2002: Image Fusion "Fusion

Pelizzari, Charles A.

184

An Improved Bioluminescence Resonance Energy Transfer Strategy for Imaging Intracellular Events in Single Cells and Living Subjects  

Science Journals Connector (OSTI)

...Bioluminescence resonance energy transfer|Renilla luciferase|Green fluorescent protein...species involved in energy transfer to Renilla green fluorescent protein...Blotting, Western Energy Transfer Fibrosarcoma...metabolism pathology Green Fluorescent Proteins...

Abhijit De; Andreas Markus Loening; and Sanjiv Sam Gambhir

2007-08-01T23:59:59.000Z

185

Bio-Med Variable Field MRI Project | Superconducting Magnet Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

186

Mapping B1-induced eddy current effects near metallic structures in MR images: A comparison of simulation and experiment  

Science Journals Connector (OSTI)

Abstract Magnetic resonance imaging (MRI) in the presence of metallic structures is very common in medical and non-medical fields. Metallic structures cause MRI image distortions by three mechanisms: (1) static field distortion through magnetic susceptibility mismatch, (2) eddy currents induced by switched magnetic field gradients and (3) radio frequency (RF) induced eddy currents. Single point ramped imaging with T1 enhancement (SPRITE) MRI measurements are largely immune to susceptibility and gradient induced eddy current artifacts. As a result, one can isolate the effects of metal objects on the RF field. The RF field affects both the excitation and detection of the magnetic resonance (MR) signal. This is challenging with conventional MRI methods, which cannot readily separate the three effects. RF induced MRI artifacts were investigated experimentally at 2.4 T by analyzing image distortions surrounding two geometrically identical metallic strips of aluminum and lead. The strips were immersed in agar gel doped with contrast agent and imaged employing the conical SPRITE sequence. B1 mapping with pure phase encode SPRITE was employed to measure the B1 field around the strips of metal. The strip geometry was chosen to mimic metal electrodes employed in electrochemistry studies. Simulations are employed to investigate the RF field induced eddy currents in the two metallic strips. The RF simulation results are in good agreement with experimental results. Experimental and simulation results show that the metal has a pronounced effect on the B1 distribution and B1 amplitude in the surrounding space. The electrical conductivity of the metal has a minimal effect.

S. Vashaee; F. Goora; M.M. Britton; B. Newling; B.J. Balcom

2015-01-01T23:59:59.000Z

187

Erroneous and inappropriate use of gamma fits to tracer-dilution curves in magnetic resonance imaging and nuclear medicine1  

E-Print Network [OSTI]

imaging and nuclear medicine1 Xingfeng Lia , Jie Tiana , R.K. Millardb, * a Medical Image Processing Group applica- tions of this versatile fitting function occur in nuclear med- icine [2,3], with the same of particles, taking account of back-dispersion in diffusion processes. An up-to-date introduction

Tian, Jie

188

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 uses 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. (Lockport, IL); Klingler, Robert J. (Westmont, IL); Woelk, Klaus (Wachtberg, DE); Gerald, II, Rex E. (Brookfield, IL)

2000-01-01T23:59:59.000Z

189

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

190

Injection-controlled laser resonator  

DOE Patents [OSTI]

A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

Chang, J.J.

1995-07-18T23:59:59.000Z

191

Chapter 10 - Cross-Subject Comparison of Local Diffusion MRI Parameters  

Science Journals Connector (OSTI)

Abstract There has been much interest in using magnetic resonance diffusion imaging to provide information about anatomical connectivity in the brain by measuring the anisotropic diffusion of water in white matter tracts. One of the measures most commonly derived from diffusion data is fractional anisotropy (FA), which quantifies how strongly directional the local tract structure is. Many imaging studies are starting to use FA images (and other diffusion-derived parameters) in voxelwise statistical analyses, in order to localize brain changes related to development, degeneration, and disease. However, in order to compare such local changes in diffusion parameters across subjects, it is necessary to solve the “correspondence problem,” to determine which location in each subject’s diffusion images corresponds to the equivalent anatomical location in the other subjects. Some researchers have used generic registration methods to try to achieve correspondence, some have used region-of-interest approaches, some have used tractography to parameterize diffusion parameters according to anatomical location, and some have combined different aspects of all of these approaches to attempt to achieve robust and accurate correspondence. This chapter describes many such approaches in the literature, discusses the potential richness available when using more diffusion-derived information than purely the FA, and also illustrates some of the dangers that the researcher should be aware of when interpreting the analysis of multi-subject diffusion MRI studies.

Stephen M. Smith; Gordon Kindlmann; Saad Jbabdi

2014-01-01T23:59:59.000Z

192

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

193

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

2013-08-27T23:59:59.000Z

194

Image Registration Using Implicit Similarity and Pixel Migration A. Averbuch1  

E-Print Network [OSTI]

of remote-sensing 1 #12;(Sar, Flir, IR and optical sensors) [3, 4] and medical image registration (CT, MRI

Averbuch, Amir

195

Dual MRI T1 and T2(?) contrast with size-controlled iron oxide nanoparticles  

Science Journals Connector (OSTI)

Abstract Contrast-enhancing magnetic resonance mechanism, employing either positive or negative signal changes, has contrast-specific signal characteristics. Although highly sensitive, negative contrast typically decreases the resolution and spatial specificity of MRI, whereas positive contrast lacks a high contrast-to-noise ratio but offers high spatial accuracy. To overcome these individual limitations, dual-contrast acquisitions were performed using iron oxide nanoparticles and a pair of MRI acquisitions. Specifically, vascular signals in MR angiography were positively enhanced using ultrashort echo (UTE) acquisition, which provided highly resolved vessel structures with increased vessel/tissue contrast. In addition, fast low angle shot (FLASH) acquisition yielded strong negative vessel contrast, resulting in the higher number of discernible vessel branches than those obtained from the UTE method. Taken together, the high sensitivity of the negative contrast delineated ambiguous vessel regions, whereas the positive contrast effectively eliminated the false negative contrast areas (e.g., airways and bones), demonstrating the benefits of the dual-contrast method. From the Clinical Editor In this study, the MRI properties of iron oxide nanoparticles were studied in an animal model. These contrast agents are typically considered negative contrast materials, leading to signal loss on T2* weighted images, but they also have known T1 effects as well, which is lower than that of standard positive contrast agents (like gadolinium or manganese) but is still detectable. This dual property was utilized in this study, demonstrating high sensitivity of the negative contrast in delineating ambiguous vessel regions, whereas the positive contrast eliminated false negative contrast areas (areas giving rise to susceptibility effects).

Hoesu Jung; Bumwoo Park; Changkyung Lee; Junghun Cho; Jiyeon Suh; JangYeon Park; YoungRo Kim; Jeongkon Kim; Gyunggoo Cho; HyungJoon Cho

2014-01-01T23:59:59.000Z

196

A triple-resonant RF coil setup for 1H, 23Na and 39K MR imaging of the rat brain at 9.4T M. A. Augath1,2  

E-Print Network [OSTI]

A triple-resonant RF coil setup for 1H, 23Na and 39K MR imaging of the rat brain at 9.4T M. A. Augath1,2 , P. Heiler1 , S. Kirsch1 , and L. R. Schad1 1 Computer Assisted Clinical Medicine, Faculty concentrations of 23 Na and 39 K offers a very promising approach in clinical diagnostics. For MR imaging of both

197

Nuclear magnetic resonance study of Gd-based nanoparticles to tag boron compounds in boron neutron capture therapy  

SciTech Connect (OSTI)

We report the investigation of new organic complexes containing a magnetic moment (Gd-based molecular nanomagnets), which can serve the double purpose of acting as boron neutron capture therapy (BNCT) agents, and at the same time act as contrast agents to detect the molecule in the tissue by a proton magnetic resonance imaging (MRI). We also explore the possibility of monitoring the concentration of the BNCT agent directly via proton and boron NMR relaxation. The absorption of {sup 10}B-enriched molecules inside tumoral liver tissues has been shown by NMR measurements and confirmed by {alpha} spectroscopy. A new molecular Gd-tagged nanomagnet and BNCT agent (GdBPA) has been synthesized and characterized measuring its relaxivity R{sub 1} between 10 kHz and 66 MHz, and its use as a contrast agent in MRI has been demonstrated. The NMR-based evidence of the absorption of GdBPA into living tumoral cells is also shown.

Corti, M.; Bonora, M.; Borsa, F. [Dipartimento di Fisica A.Volta, Unita CNISM e Unita INSTM, Via Bassi 6, Universita di Pavia, I-27100 Pavia (Italy); Bortolussi, S.; Protti, N.; Santoro, D.; Stella, S.; Altieri, S. [Dipartimento di Fisica Nucleare e Teorica e INFN Pavia, Via Bassi 6, Universita di Pavia, I-27100 Pavia (Italy); Zonta, C.; Clerici, A. M.; Cansolino, L.; Ferrari, C.; Dionigi, P. [Dipartimento di Scienze Chirurgiche, Laboratorio di Chirurgia Sperimentale Botta2, Via Ferrata 9, Universita di Pavia, I-27100 Pavia (Italy); Porta, A.; Zanoni, G.; Vidari, G. [Dipartimento di Chimica Organica, Via Taramelli 10, Universita di Pavia, I-27100 Pavia (Italy)

2011-04-01T23:59:59.000Z

198

Dynamic Contrast-Enhanced Magnetic Resonance Imaging as a Predictor of Outcome in Head-and-Neck Squamous Cell Carcinoma Patients With Nodal Metastases  

SciTech Connect (OSTI)

Purpose: Dynamic contrast-enhanced MRI (DCE-MRI) can provide information regarding tumor perfusion and permeability and has shown prognostic value in certain tumors types. The goal of this study was to assess the prognostic value of pretreatment DCE-MRI in head and neck squamous cell carcinoma (HNSCC) patients with nodal disease undergoing chemoradiation therapy or surgery. Methods and Materials: Seventy-four patients with histologically proven squamous cell carcinoma and neck nodal metastases were eligible for the study. Pretreatment DCE-MRI was performed on a 1.5T MRI. Clinical follow-up was a minimum of 12 months. DCE-MRI data were analyzed using the Tofts model. DCE-MRI parameters were related to treatment outcome (progression-free survival [PFS] and overall survival [OS]). Patients were grouped as no evidence of disease (NED), alive with disease (AWD), dead with disease (DOD), or dead of other causes (DOC). Prognostic significance was assessed using the log-rank test for single variables and Cox proportional hazards regression for combinations of variables. Results: At last clinical follow-up, for Stage III, all 12 patients were NED. For Stage IV, 43 patients were NED, 4 were AWD, 11 were DOD, and 4 were DOC. K{sup trans} is volume transfer constant. In a stepwise Cox regression, skewness of K{sup trans} (volume transfer constant) was the strongest predictor for Stage IV patients (PFS and OS: p <0.001). Conclusion: Our study shows that skewness of K{sup trans} was the strongest predictor of PFS and OS in Stage IV HNSCC patients with nodal disease. This study suggests an important role for pretreatment DCE-MRI parameter K{sup trans} as a predictor of outcome in these patients.

Shukla-Dave, Amita, E-mail: davea@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Jansen, Jacobus F.A. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Thaler, Howard T. [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Stambuk, Hilda E. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Fury, Matthew G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Patel, Snehal G. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Moreira, Andre L. [Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Sherman, Eric [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Karimi, Sasan [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Wang, Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Kraus, Dennis; Shah, Jatin P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Pfister, David G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); and others

2012-04-01T23:59:59.000Z

199

Magnetic Resonance Imaging-Based Target Volume Delineation in Radiation Therapy Treatment Planning for Brain Tumors Using Localized Region-Based Active Contour  

SciTech Connect (OSTI)

Purpose: To evaluate the clinical application of a robust semiautomatic image segmentation method to determine the brain target volumes in radiation therapy treatment planning. Methods and Materials: A local robust region-based algorithm was used on MRI brain images to study the clinical target volume (CTV) of several patients. First, 3 oncologists delineated CTVs of 10 patients manually, and the process time for each patient was calculated. The averages of the oncologists’ contours were evaluated and considered as reference contours. Then, to determine the CTV through the semiautomatic method, a fourth oncologist who was blind to all manual contours selected 4-8 points around the edema and defined the initial contour. The time to obtain the final contour was calculated again for each patient. Manual and semiautomatic segmentation were compared using 3 different metric criteria: Dice coefficient, Hausdorff distance, and mean absolute distance. A comparison also was performed between volumes obtained from semiautomatic and manual methods. Results: Manual delineation processing time of tumors for each patient was dependent on its size and complexity and had a mean (±SD) of 12.33 ± 2.47 minutes, whereas it was 3.254 ± 1.7507 minutes for the semiautomatic method. Means of Dice coefficient, Hausdorff distance, and mean absolute distance between manual contours were 0.84 ± 0.02, 2.05 ± 0.66 cm, and 0.78 ± 0.15 cm, and they were 0.82 ± 0.03, 1.91 ± 0.65 cm, and 0.7 ± 0.22 cm between manual and semiautomatic contours, respectively. Moreover, the mean volume ratio (=semiautomatic/manual) calculated for all samples was 0.87. Conclusions: Given the deformability of this method, the results showed reasonable accuracy and similarity to the results of manual contouring by the oncologists. This study shows that the localized region-based algorithms can have great ability in determining the CTV and can be appropriate alternatives for manual approaches in brain cancer.

Aslian, Hossein [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Sadeghi, Mahdi [Agricultural, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of); Mahdavi, Seied Rabie [Department of Medical Physics, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Babapour Mofrad, Farshid [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Astarakee, Mahdi, E-mail: M-Astarakee@Engineer.com [Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Khaledi, Navid [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Fadavi, Pedram [Department of Radiation Oncology, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2013-09-01T23:59:59.000Z

200

Diffusion MRI of Complex Tissue Structure David Solomon Tuch  

E-Print Network [OSTI]

Diffusion MRI of Complex Tissue Structure by David Solomon Tuch B.A., Physics, University Solomon Tuch Submitted to the Division of Health Sciences and Technology on January 11, 2002, in partial to be beyond the scope of diffusion imaging methodology. Thesis Supervisor: Van Jay Wedeen Title: Associate

Duncan, James 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.


201

Nuclear magnetic resonance measurements of velocity distributions in an ultrasonically vibrated granular bed  

Science Journals Connector (OSTI)

...Eakins, Fabrice Pierron and Clive Siviour Nuclear magnetic resonance measurements of velocity...Part 1) . We report the results of nuclear magnetic resonance imaging experiments...granular bed|ultrasonic fluidization|nuclear magnetic resonance|magnetic resonance...

2014-01-01T23:59:59.000Z

202

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 (OSTI)

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

203

Imaging  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

204

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

205

3D and 4D magnetic susceptibility tomography based on complex MR images  

DOE Patents [OSTI]

Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.

Chen, Zikuan; Calhoun, Vince D

2014-11-11T23:59:59.000Z

206

Fundamentals of Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

All the materials and living objects around us are composed of atoms. Atoms consist of three main particles that are positively charged protons, negatively charged electrons, and neutrons without any charge. T...

Muhammed Elmao?lu; Azim Çelik PhD

2012-01-01T23:59:59.000Z

207

E-Print Network 3.0 - artery magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resonance Imaging Laboratory Winter 2010 Syllabus Week... resonance Build your own coil and use it to scan Compare predicted and measured field profiles 8 Diffusion......

208

Ultra-low field magnetic resonance using optically pumped noble gases and SQUID detection  

E-Print Network [OSTI]

McGeer. Science, Positron tomography and nuclear magneticmagnetic resonance technology for medical studies. Science,magnetic resonance images of the human arm. M easur'ement Science (

Wong-Foy, Annjoe G.

2010-01-01T23:59:59.000Z

209

E-Print Network 3.0 - abdominal magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

between men and women at rest and during lower Summary: resonance-compatible exercise bicycle, magnetic resonance imaging techniques, and custom data processing... at all. We have...

210

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":""}]}

211

Fluorinated Nanoparticles: A Novel Technology Platform for Multimodal Biomedical Imaging Applications  

E-Print Network [OSTI]

in microbubble contrast agents for ultrasound imaging, positron sources for PET imaging, and as an imaging probe in 19F MRI. Additionally, fluorinated organic compounds generate a high ionization yield of fluorine in secondary ion mass spectrometry (SIMS), which...

Bailey, Mark Michael

2010-07-26T23:59:59.000Z

212

Tissue microstructural changes in dementia with Lewy bodies revealed by quantitative MRI  

E-Print Network [OSTI]

-linearly normalized to standard MNI space (www.mni.mcgill.ca) using the diffeomorphic registration algorithm (DARTEL) [24] in SPM. Raw qT1 and qT2 imaging datasets were corrected for field inhomogeneities using B0 maps and the PRELUDE/FUGUE algorithm in FSL [25... evident atrophy is clinically promising. Compared to nuclear imaging and structural MRI, quantitative MRI is a new and versatile diagnostic tool in investigating neurobiological changes in DLB, with potential for the early detection of DLB since...

Su, Li; Blamire, Andrew M.; Watson, Rosie; He, Jiabao; Aribisala, Benjamin; O’Brien, John T.

2014-01-01T23:59:59.000Z

213

Surface Plasmon Resonance (SPR) Reflectance Imaging: A Label-Free/Real-Time Mapping of Microscale Mixture Concentration Fields (Water+Ethanol)  

E-Print Network [OSTI]

Mixture Concentration Fields (Water+Ethanol) Iltai Kim and Kenneth D. Kihm Department of Mechanical (water+ethanol) concentration fields with surface plasmon resonance (SPR) reflectance technique based the refractive index and mixture concentration fields. The presented results show that ethanol penetrates

Kihm, IconKenneth David

214

First steps in using machine learning on fMRI data to predict intrusive memories of traumatic film footage  

Science Journals Connector (OSTI)

Abstract After psychological trauma, why do some only some parts of the traumatic event return as intrusive memories while others do not? Intrusive memories are key to cognitive behavioural treatment for post-traumatic stress disorder, and an aetiological understanding is warranted. We present here analyses using multivariate pattern analysis (MVPA) and a machine learning classifier to investigate whether peri-traumatic brain activation was able to predict later intrusive memories (i.e. before they had happened). To provide a methodological basis for understanding the context of the current results, we first show how functional magnetic resonance imaging (fMRI) during an experimental analogue of trauma (a trauma film) via a prospective event-related design was able to capture an individual's later intrusive memories. Results showed widespread increases in brain activation at encoding when viewing a scene in the scanner that would later return as an intrusive memory in the real world. These fMRI results were replicated in a second study. While traditional mass univariate regression analysis highlighted an association between brain processing and symptomatology, this is not the same as prediction. Using MVPA and a machine learning classifier, it was possible to predict later intrusive memories across participants with 68% accuracy, and within a participant with 97% accuracy; i.e. the classifier could identify out of multiple scenes those that would later return as an intrusive memory. We also report here brain networks key in intrusive memory prediction. MVPA opens the possibility of decoding brain activity to reconstruct idiosyncratic cognitive events with relevance to understanding and predicting mental health symptoms.

Ian A. Clark; Katherine E. Niehaus; Eugene P. Duff; Martina C. Di Simplicio; Gari D. Clifford; Stephen M. Smith; Clare E. Mackay; Mark W. Woolrich; Emily A. Holmes

2014-01-01T23:59:59.000Z

215

A Novel Nuclear Magnetic Resonance (NMR) Imaging Method for Measuring the Water Front Penetration Rate in Hydrophilic Polymer Matrix Capsule Plugs and Its Role in Drug Release  

Science Journals Connector (OSTI)

An NMR imaging method was developed to estimate the rate of water movement in slow-release capsule ... transverse plane of each plug. The water penetration rate was determined by comparison of the cut ... the plu...

Muhammad Ashraf; Virginia L. luorno; David Coffin-Beach…

1994-05-01T23:59:59.000Z

216

Implementation Strategies of A Contract-based MRI Examination Reservation Process for Stroke Patients  

E-Print Network [OSTI]

1 Implementation Strategies of A Contract-based MRI Examination Reservation Process for Stroke/22/2013 Corresponding author: Prof. Xiaolan XIE Abstract: Timely imaging examinations are critical for stroke patients) are especially reserved for Neural Vascular Department (NVD) treating stroke patients. Patients either wait

Paris-Sud XI, Université de

217

MRI based diffusion and perfusion predictive model to estimate stroke Stephen E. Rosea,  

E-Print Network [OSTI]

MRI based diffusion and perfusion predictive model to estimate stroke evolution Stephen E. Rosea and perfusion images acquired in the acute stage of stroke. The validity of this methodology was tested on novel patient data including data acquired from an independent stroke clinic. Regions-of-interest (ROIs

McLachlan, Geoff

218

Validation of Imaging With Pathology in Laryngeal Cancer: Accuracy of the Registration Methodology  

SciTech Connect (OSTI)

Purpose: To investigate the feasibility and accuracy of an automated method to validate gross tumor volume (GTV) delineations with pathology in laryngeal and hypopharyngeal cancer. Methods and Materials: High-resolution computed tomography (CT{sub HR}), magnetic resonance imaging (MRI), and positron emission tomography (PET) scans were obtained from 10 patients before total laryngectomy. The GTV was delineated separately in each imaging modality. The laryngectomy specimen was sliced transversely in 3-mm-thick slices, and whole-mount hematoxylin-eosin stained (H and E) sections were obtained. A pathologist delineated tumor tissue in the H and E sections (GTV{sub PATH}). An automatic three-dimensional (3D) reconstruction of the specimen was performed, and the CT{sub HR}, MRI, and PET were semiautomatically and rigidly registered to the 3D specimen. The accuracy of the pathology-imaging registration and the specimen deformation and shrinkage were assessed. The tumor delineation inaccuracies were compared with the registration errors. Results: Good agreement was observed between anatomical landmarks in the 3D specimen and in the in vivo images. Limited deformations and shrinkage (3% {+-} 1%) were found inside the cartilage skeleton. The root mean squared error of the registration between the 3D specimen and the CT, MRI, and PET was on average 1.5, 3.0, and 3.3 mm, respectively, in the cartilage skeleton. The GTV{sub PATH} volume was 7.2 mL, on average. The GTVs based on CT, MRI, and PET generated a mean volume of 14.9, 18.3, and 9.8 mL and covered the GTV{sub PATH} by 85%, 88%, and 77%, respectively. The tumor delineation inaccuracies exceeded the registration error in all the imaging modalities. Conclusions: Validation of GTV delineations with pathology is feasible with an average overall accuracy below 3.5 mm inside the laryngeal skeleton. The tumor delineation inaccuracies were larger than the registration error. Therefore, an accurate histological validation of anatomical and functional imaging techniques for GTV delineation is possible in laryngeal cancer patients.

Caldas-Magalhaes, Joana, E-mail: J.CaldasMagalhaes@umcutrecht.nl [Department of Radiotherapy, University Medical Center Utrecht (Netherlands); Kasperts, Nicolien [Department of Radiotherapy, University Medical Center Utrecht (Netherlands); Kooij, Nina [Department of Pathology, University Medical Center Utrecht (Netherlands); Berg, Cornelis A.T. van den; Terhaard, Chris H.J.; Raaijmakers, Cornelis P.J.; Philippens, Marielle E.P. [Department of Radiotherapy, University Medical Center Utrecht (Netherlands)

2012-02-01T23:59:59.000Z

219

Automated fibroglandular tissue segmentation and volumetric density estimation in breast MRI using an atlas-aided fuzzy C-means method  

SciTech Connect (OSTI)

Purpose: Breast magnetic resonance imaging (MRI) plays an important role in the clinical management of breast cancer. Studies suggest that the relative amount of fibroglandular (i.e., dense) tissue in the breast as quantified in MR images can be predictive of the risk for developing breast cancer, especially for high-risk women. Automated segmentation of the fibroglandular tissue and volumetric density estimation in breast MRI could therefore be useful for breast cancer risk assessment. Methods: In this work the authors develop and validate a fully automated segmentation algorithm, namely, an atlas-aided fuzzy C-means (FCM-Atlas) method, to estimate the volumetric amount of fibroglandular tissue in breast MRI. The FCM-Atlas is a 2D segmentation method working on a slice-by-slice basis. FCM clustering is first applied to the intensity space of each 2D MR slice to produce an initial voxelwise likelihood map of fibroglandular tissue. Then a prior learned fibroglandular tissue likelihood atlas is incorporated to refine the initial FCM likelihood map to achieve enhanced segmentation, from which the absolute volume of the fibroglandular tissue (|FGT|) and the relative amount (i.e., percentage) of the |FGT| relative to the whole breast volume (FGT%) are computed. The authors' method is evaluated by a representative dataset of 60 3D bilateral breast MRI scans (120 breasts) that span the full breast density range of the American College of Radiology Breast Imaging Reporting and Data System. The automated segmentation is compared to manual segmentation obtained by two experienced breast imaging radiologists. Segmentation performance is assessed by linear regression, Pearson's correlation coefficients, Student's pairedt-test, and Dice's similarity coefficients (DSC). Results: The inter-reader correlation is 0.97 for FGT% and 0.95 for |FGT|. When compared to the average of the two readers’ manual segmentation, the proposed FCM-Atlas method achieves a correlation ofr = 0.92 for FGT% and r = 0.93 for |FGT|, and the automated segmentation is not statistically significantly different (p = 0.46 for FGT% and p = 0.55 for |FGT|). The bilateral correlation between left breasts and right breasts for the FGT% is 0.94, 0.92, and 0.95 for reader 1, reader 2, and the FCM-Atlas, respectively; likewise, for the |FGT|, it is 0.92, 0.92, and 0.93, respectively. For the spatial segmentation agreement, the automated algorithm achieves a DSC of 0.69 ± 0.1 when compared to reader 1 and 0.61 ± 0.1 for reader 2, respectively, while the DSC between the two readers’ manual segmentation is 0.67 ± 0.15. Additional robustness analysis shows that the segmentation performance of the authors' method is stable both with respect to selecting different cases and to varying the number of cases needed to construct the prior probability atlas. The authors' results also show that the proposed FCM-Atlas method outperforms the commonly used two-cluster FCM-alone method. The authors' method runs at ?5 min for each 3D bilateral MR scan (56 slices) for computing the FGT% and |FGT|, compared to ?55 min needed for manual segmentation for the same purpose. Conclusions: The authors' method achieves robust segmentation and can serve as an efficient tool for processing large clinical datasets for quantifying the fibroglandular tissue content in breast MRI. It holds a great potential to support clinical applications in the future including breast cancer risk assessment.

Wu, Shandong; Weinstein, Susan P.; Conant, Emily F.; Kontos, Despina, E-mail: despina.kontos@uphs.upenn.edu [Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)] [Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2013-12-15T23:59:59.000Z

220

Stanford Radiology LPCH Fast Pediatric MRI  

E-Print Network [OSTI]

Stanford Radiology LPCH Fast Pediatric MRI Shreyas Vasanawala, MD/PhD Stanford University Lucile Radiology LPCH Thank you Par Lab Briefer, lighter, safer anesthesia for pediatric MRI #12; practice #12;Stanford Radiology LPCH #12;Stanford Radiology LPCH Current Solution INVASIVE LIMITS ACCESS

California at Berkeley, University of

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221

Brain tumour segmentation in MRI: knowledge-based system and region growing approach  

Science Journals Connector (OSTI)

We present in this paper a method for MRI brain tumour segmentation, so we propose a general framework that is a combination of paradigms, in order to have a hybrid segmentation method, automatic and unsupervised. In the first phase, expertise and characteristics derived from MRI images are combined to define heuristics for the development of the classification approach. In the second phase, refinement of the tumour contour is achieved by using the region growing method. The results are good and visually validated by radiologists.

Badredine Sayah; Bornia Tighiouart

2014-01-01T23:59:59.000Z

222

Non Destructive Thermal Analysis and In Situ Investigation of Creep Mechanism of Graphite and Ceramic Composites using Phase-sensitive THz Imaging & Nonlinear Resonant Ultrasonic Spectroscopy  

SciTech Connect (OSTI)

In this project, we conducted a comprehensive study on nuclear graphite properties with terahertz (THz) imaging. Graphite samples from Idaho National Laboratory were carefully imaged by continuous wave (CW) THz. The CW THz imaging of graphite shows that the samples from different billet with different fabricating conditions have different pore size and structure. Based on this result, we then used a phase sensitive THz system to study the graphite properties. In this exploration, various graphite were studied. By imaging nuclear graphite samples in reflection mode at nine different incident polarization angles using THz timedomain- spectroscopy, we find that different domain distributions and levels of porosity will introduce polarization dependence in THz reflectivity. Sample with higher density is less porous and has a smaller average domain distribution. As a consequence, it is less polarization-dependent and the polarizationdependent frequency is higher. The results also show that samples oxidized at higher temperatures tend to be more polarization dependent. The graphite from the external billet is more polarization dependent compared to that from the center billet. In addition, we performed laser-based ultrasonic measurements on these graphite samples. The denser, unoxidized samples allow surface acoustic waves to propagate more rapidly than in the samples that had already undergone oxidation. Therefore, for the oxidized samples, the denser samples show less polarization-dependence, higher polarization-dependent frequency, and allow the surface acoustic waves propagate faster.

XI-Cheng Zhang; David Hurley; Albert Redo-sanchez

2012-11-26T23:59:59.000Z

223

Partnering with Engineers to Identify and Empirically Evaluate Delays in Magnetic Resonance Imaging: Laying the Foundations for Quality Improvement and System-based Practice in Radiology  

Science Journals Connector (OSTI)

Rationale and Objectives The aim of this study was to evaluate the feasibility of partnering with engineering students and critically examining the merit of the problem identification and analyses students generated in identifying sources impeding effective turnaround in a large university department of diagnostic radiology. Turnaround involves the time and activities beginning when a patient enters the magnetic resonance scanner room until the patient leaves, minus the time the scanner is conducting the protocol. Materials and Methods A prospective observational study was conducted, in which four senior undergraduate industrial and operations engineering students interviewed magnetic resonance staff members and observed all shifts. On the basis of 150 hours of observation, the engineering students identified 11 process steps (eg, changing coils). They charted machine use for all shifts, providing a breakdown of turnaround time between appropriate process and non-value-added time. To evaluate the processes occurring in the scanning room, the students used a work-sampling schedule in which a beeper sounded 2.5 times per hour, signaling the technologist to identify which of 11 process steps was occurring. This generated 2147 random observations over a 3-week period. Results The breakdown of machine use over 105 individual studies showed that non-value-added time accounted for 62% of turnaround time. Analysis of 2147 random samples of work showed that scanners were empty and waiting for patients 15% of the total time. Analyses showed that poor communication delayed the arrival of patients and that no one had responsibility for communicating when scanning was done. Conclusions Engineering students used rigorous study design and sampling methods to conduct interviews and observations. This led to data-driven definition of problems and potential solutions to guide systems-based improvement.

Catherine J. Brandon; Michael Holody; Geoffrey Inch; Michael Kabcenell; Diane Schowalter; Patricia B. Mullan

2012-01-01T23:59:59.000Z

224

Absorption Mode FT-ICR Mass Spectrometry Imaging. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Imaging. Absorption Mode FT-ICR Mass Spectrometry Imaging. Abstract: Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power...

225

Motion Estimation in Static Magnetic Resonance Elastography  

E-Print Network [OSTI]

is an important and one of the most rapidly advancing areas of research in medicine. Many imaging modalities already exist and are widely used in diagnostics radiology as well as in treatment assistance in oncology. MRI is one of these modalities... modulus, or shear modulus). Over the past few decades, there have been numerous investigations conducted to characterize the mechanical properties of biological tissue systems [13, 14]. Much of the work has focused on bone, dental materials...

Popel, Elena

2009-12-09T23:59:59.000Z

226

E-Print Network 3.0 - axis cardiac mri Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

<< < 1 2 3 4 5 > >> 1 Real-Time Color-Flow Magnetic ResonanceImaging of Congenital Heart Disease E. De La Pena-Almaguer, K. S. Nayak, M. Terashima, P.C. Yang, Summary:...

227

Use of MRI fusion second-look ultrasound in breast cancer: can MRI US fusion reduce the need for MRI-guided biopsy?  

Science Journals Connector (OSTI)

Breast MRI is being increasingly used in breast cancer to look for extent of disease, in high-risk screening and in the dense breast. Frequently incidental lesions are detected on MRI that require second-look ult...

SE McWilliams

2012-11-01T23:59:59.000Z

228

Final Report: A CdZnTe detector for MRI-compatible SPECT Systems  

SciTech Connect (OSTI)

The key objective of this project is to develop the enabling technology for future MRI-compatible nuclear (e.g. SPECT) imaging system, and to demonstrate the feasibility of performing simultaneous MR and SPECT imaging studies of the same object. During the past three years, we have developed (a) a MRI-compatible ultrahigh resolution gamma ray detector and associated readout electronics, (b) a theoretical approach for modeling the effect of strong magnetic field on SPECT image quality, and (c) a maximum-likelihood (ML) based reconstruction routine with correction for the MR-induced distortion. With this support, we have also constructed a four-head MR-compatible SPECT system and tested the system inside a 3-T clinical MR-scanner located on UI campus. The experimental results obtained with this system have clearly demonstrated that sub-500um spatial resolution can be achieved with a SPECT system operated inside a 3-T MRI scanner. During the past three years, we have accomplished most of the major objectives outlined in the original proposal. These research efforts have laid out a solid foundation the development of future MR-compatible SPECT systems for both pre-clinical and clinical imaging applications.

Meng, Ling-Jian

2012-12-27T23:59:59.000Z

229

Novel in vivo imaging techniques for trafficking the behavior of subventricular zone neural stem cells (SVZSC) and SVZSC induced functional repair  

SciTech Connect (OSTI)

Adult progenitor cells hold promise for therapeutic treatment where there has been a disabling loss of function due to death of cells from trauma, disease or aging. However, it will be essential in clinical application to be able to follow the fate of the transplanted cells over time using in vivo tracking methods. We have developed protocol for labeling of progenitor cells to monitor cell trafficking by high resolution magnetic resonance imaging (MRI) and super high resolution positron emission tomography (PET). We have transfected rat subventricular zone stem cells (SVZ, progenitor cell line) and another control cell line (PC12, pheochromocytoma cells) utilizing super paramagnetic iron oxide and poly-L-lysine complex for MR imaging or radiolabeling with 18F-fluor deoxy-D- glucose for PET imaging. The labeled cells were transplanted into the rostral migratory stream (RMS) or striatum of normal or 6-hydroxydopamine lesioned Spraque-Dawley rats. Longitudinal MRI studies (up to 40 days) showed that transplantation site has significant impact to the fate of the cells; when SVZ cells were transplanted into the RMS, cells migrated several centimeter into the olfactory bulb; after transplantation into the striatum, the migration was minimal, only 2 mm. PC 12 cells grew a massive tumor after the striatal implantation and significantly smaller tumor after the RMS implantation. PET studies conducted immediately after transplantation verified the transplantation site. MRI studies were able to show the whole path of migration in one image, since part of the cells die during migration and will get detected because of iron content. Endpoint histological studies verified the cell survival and immunohistochemical studies revealed the differentiation of the transplanted cells into astrocytes and neurons.

Anna-Liisa Brownell

2003-11-28T23:59:59.000Z

230

Regenerative feedback resonant circuit  

DOE Patents [OSTI]

A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

2014-09-02T23:59:59.000Z

231

Evaluation of LDH-A and Glutaminase Inhibition In Vivo by Hyperpolarized 13C-Pyruvate Magnetic Resonance Spectroscopy of Tumors  

Science Journals Connector (OSTI)

...Neurology and Brain Science Institute, Johns Hopkins...Hyperpolarized 13C magnetic resonance spectroscopy...31P and 13C nuclear magnetic resonance.Science 1979;205:160-6...hyperpolarized 13C magnetic resonance imaging for...

Prasanta Dutta; Anne Le; David L. Vander Jagt; Takashi Tsukamoto; Gary V. Martinez; Chi V. Dang; and Robert J. Gillies

2013-07-15T23:59:59.000Z

232

Analyzing 3D Images of the Brain NICHOLAS AYACHE  

E-Print Network [OSTI]

Analyzing 3D Images of the Brain NICHOLAS AYACHE OVERVIEW During the past 5 years, there has been research. Along these lines, and focusing on 3D images of the brain obtained with CT, MRI, SPECT, and PET for an objective analysis of 3D images of the brain. Such methods include segmentation, shape analysis, rigid

Paris-Sud XI, Université de

233

1610 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 11, 2012 MRI-Derived 3-D-Printed Breast Phantom  

E-Print Network [OSTI]

1610 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 11, 2012 MRI-Derived 3-D-Printed Breast--We propose a 3-D-printed breast phantom for use in preclinical experimental microwave imaging studies the proce- dure for generating the 3-D-printed breast phantom and present the measured dielectric properties

Hagness, Susan C.

234

Abstract 380: Magnetic nanoplatforms for tumor targeting, imaging and energy delivery  

Science Journals Connector (OSTI)

...cancer cell lines. An inversion...high power field; P 0.0001...the sodium magnetic resonance...human cell lines (DU145...tumors at the magnetic field strength...are: MRI, magnetic resonance...high power field. Fig. 1...time. The lines are the theoretical...

Srinivas Sridhar; Robert Campbell; Dattatri Nagesha; and Evin Gultepe

2011-04-15T23:59:59.000Z

235

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

236

Automatic Segmentation of Neonatal Brain MRI Marcel Prastawa, 2  

E-Print Network [OSTI]

Automatic Segmentation of Neonatal Brain MRI 1 Marcel Prastawa, 2 John Gilmore, 3 Weili Lin, and 1 segmentation method for neonatal MRI. The analysis and study of neonatal brain MRI is of great interest due probabilistic brain atlas to select training samples and to be used as a spatial prior. The method first uses

Prastawa, Marcel

237

IR Principles for Content-based Indexing and Retrieval of Functional Brain Images  

E-Print Network [OSTI]

IR Principles for Content-based Indexing and Retrieval of Functional Brain Images Bing Bai, Paul of a "library of brain images", which implies not only a repository of brain images, but also efficient search worked with a collection of functional MRI brain images assembled in the study of several distinct cogni

238

E-Print Network 3.0 - advance molecular imaging Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resonance and Spectroscopy Imaging ... Source: Jacob, Mathews - Departments of Biomedical Engineering & Electrical and Computer Engineering, University of Rochester...

239

Isotropic three-dimensional MRI-Fricke-infused gel dosimetry  

SciTech Connect (OSTI)

Purpose: Fricke-infused gel has been shown to be a simple and attainable method for the conformal measurement of absorbed radiation dose. Nevertheless, its accuracy is seriously hindered by the irreversible ferric ion diffusion during magnetic resonance imaging, particularly when three-dimensional (3D) dose measurement in radiosurgery is considered. In this study, the authors developed a fast three-dimensional spin-echo based Fricke gel dosimetry technique to reduce the adverse effects of ferric ion diffusion and to obtain an accurate isotropic 3D dose measurement. Methods: A skull shaped phantom containing Fricke-infused gel was irradiated using Leksell Gamma Knife. The rapid image-based dosimetry technique was applied with the use of a 3D fast spin-echo magnetic resonance imaging sequence. The authors mathematically derived and experimentally validated the correlations between dose-response characteristics and parameters of the 3D fast spin-echo MR imaging sequence. Absorbed dose profiles were assessed and compared to the calculated profiles given by the Gamma Knife treatment planning system. Coefficient of variance (CV%) and coefficient of determination (R{sup 2}) were used to evaluate the precision of dose-response curve estimation. The agreement between the measured and the planned 3D dose distributions was quantified by gamma-index analysis of two acceptance criteria. Results: Proper magnetic resonance imaging parameters were explored to render an accurate three-dimensional absorbed dose mapping with a 1 mm{sup 3} isotropic image resolution. The efficacy of the dose-response estimation was approved by an R{sup 2} > 0.99 and an average CV% of 1.6%. Average gamma pass-rate between the experimentally measured and GammaPlan calculated dose distributions were 83.8% and 99.7% for 2%/2 and 3%/3 mm criteria, respectively. Conclusions: With the designed MR imaging sequence and parameters, total 3D MR acquisition time was confined to within 20 min postirradiation, during which time ferric ion diffusion effects were negligible, thus enabling an accurate 3D radiation dose measurement.

Cho, Nai-Yu; Chu, Woei-Chyn [Institute of Biomedical Engineering, National Yang-Ming University, Taipei 11221, Taiwan (China); Huang, Sung-Cheng [Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, California 90095 (United States); Chung, Wen-Yuh [Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan (China); Guo, Wan-Yuo [Department of Radiology, Taipei Veterans General Hospital, Taipei 11217, Taiwan (China)

2013-05-15T23:59:59.000Z

240

Next Generation Magnetic Resonance Imaging Contrast Agents  

E-Print Network [OSTI]

E. A. ; MacRenaris, K. W. ; Parigi, G. ; Luchinat, C. ; Ho,R. ; Eckermann, A. L. ; Parigi, G. ; Luchinat, C. ; Meade,E. A. ; MacRenaris, K. W. ; Parigi, G. ; Luchinat, C. ; Ho,

Klemm, Piper Julia

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.


241

Next Generation Magnetic Resonance Imaging Contrast Agents  

E-Print Network [OSTI]

RE 2 O 3 nanodiscs passivated with PAA-mPEO x alongside Gd-General Synthesis of PAA 28-x -mPEO x Graft Copolymers (Weegen and Mark Bailey): PAA (28 eq–CO 2 H per polymer) was

Klemm, Piper Julia

2012-01-01T23:59:59.000Z

242

MRI Beginnings - a Legacy | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Legacy From Nobel Ideas to Industrial Success - Bill Edelstein's Legacy Scott Smith 2014.06.13 Edelsteinwith-MRmachine Nuclear magnetic resonance (NMR) was discovered in...

243

Magnetic field calculations for iron oxide nanoparticles for MRI  

Science Journals Connector (OSTI)

The susceptibility effects of superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with triethylenglycol (TREG) and Polyethylen Glycol (PEG) has been studied those nanoparticles have the necessary properties to be used in the clinic as contrast media in imaging by MRI[1–3]. We are considering the behavior of the magnetic field as plane wave to explain the electrical and magnetic field produced by SPIONs. Images were acquired on a 1.5T imager Philips using mFFE Sequence. Three glass capillary tubes with a) TREG (10nm) concentration of 300 ?g/ml and PEGCOOH 6000(10nm) with 300 ?g/ml and 2% agarosa. Magnetic field simulations were calculated in Matlab. The plane wave that comes in contact with a sphere of radius a an propagation constant k1 and it is in an homogeneous space k2. We consider that the electric field is linearly polarized on x-direction with a propagation on z-positive-axis. The secondary induced field can be explained from the interior of the sphere and valid exterior points. The referred waves are transmitted and reflected this is valid only when the wavelength is smaller than the radius of the sphere. The obtained vibrational mode is an answer of the electrical oscillation and this is projection of the disturbed magnetic field. TREG-SPIONs produce more serious susceptibility artefacts compared to PEG-SPIONs. This study is promissory due to the concordance of the results of the simulations and the inhomogeneities showed in the MR images.

2014-01-01T23:59:59.000Z

244

DCE-MRI defined subvolumes of a brain metastatic lesion by principle component analysis and fuzzy-c-means clustering for response assessment of radiation therapy  

SciTech Connect (OSTI)

Purpose: To develop a pharmacokinetic modelfree framework to analyze the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data for assessment of response of brain metastases to radiation therapy. Methods: Twenty patients with 45 analyzable brain metastases had MRI scans prior to whole brain radiation therapy (WBRT) and at the end of the 2-week therapy. The volumetric DCE images covering the whole brain were acquired on a 3T scanner with approximately 5 s temporal resolution and a total scan time of about 3 min. DCE curves from all voxels of the 45 brain metastases were normalized and then temporally aligned. A DCE matrix that is constructed from the aligned DCE curves of all voxels of the 45 lesions obtained prior to WBRT is processed by principal component analysis to generate the principal components (PCs). Then, the projection coefficient maps prior to and at the end of WBRT are created for each lesion. Next, a pattern recognition technique, based upon fuzzy-c-means clustering, is used to delineate the tumor subvolumes relating to the value of the significant projection coefficients. The relationship between changes in different tumor subvolumes and treatment response was evaluated to differentiate responsive from stable and progressive tumors. Performance of the PC-defined tumor subvolume was also evaluated by receiver operating characteristic (ROC) analysis in prediction of nonresponsive lesions and compared with physiological-defined tumor subvolumes. Results: The projection coefficient maps of the first three PCs contain almost all response-related information in DCE curves of brain metastases. The first projection coefficient, related to the area under DCE curves, is the major component to determine response while the third one has a complimentary role. In ROC analysis, the area under curve of 0.88 ± 0.05 and 0.86 ± 0.06 were achieved for the PC-defined and physiological-defined tumor subvolume in response assessment. Conclusions: The PC-defined subvolume of a brain metastasis could predict tumor response to therapy similar to the physiological-defined one, while the former is determined more rapidly for clinical decision-making support.

Farjam, Reza; Tsien, Christina I.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, 1500 East Medical Center Drive, SPC 5010, Ann Arbor, Michigan 48109-5010 (United States)] [Department of Radiation Oncology, University of Michigan, 1500 East Medical Center Drive, SPC 5010, Ann Arbor, Michigan 48109-5010 (United States); Cao, Yue, E-mail: yuecao@umich.edu [Department of Radiation Oncology, University of Michigan, 1500 East Medical Center Drive, SPC 5010, Ann Arbor, Michigan 48109-5010 (United States) [Department of Radiation Oncology, University of Michigan, 1500 East Medical Center Drive, SPC 5010, Ann Arbor, Michigan 48109-5010 (United States); Department of Radiology, University of Michigan, 1500 East Medical Center Drive, Med Inn Building C478, Ann Arbor, Michigan 48109-5842 (United States); Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109-2099 (United States)

2014-01-15T23:59:59.000Z

245

The 700-1500 cm{sup ?1} region of the S{sub 1} (A{sup ~1}B{sub 2}) state of toluene studied with resonance-enhanced multiphoton ionization (REMPI), zero-kinetic-energy (ZEKE) spectroscopy, and time-resolved slow-electron velocity-map imaging (tr-SEVI) spectroscopy  

SciTech Connect (OSTI)

We report (nanosecond) resonance-enhanced multiphoton ionization (REMPI), (nanosecond) zero-kinetic-energy (ZEKE) and (picosecond) time-resolved slow-electron velocity map imaging (tr-SEVI) spectra of fully hydrogenated toluene (Tol-h{sub 8}) and the deuterated-methyl group isotopologue (?{sub 3}-Tol-d{sub 3}). Vibrational assignments are made making use of the activity observed in the ZEKE and tr-SEVI spectra, together with the results from quantum chemical and previous experimental results. Here, we examine the 700–1500 cm{sup ?1} region of the REMPI spectrum, extending our previous work on the region ?700 cm{sup ?1}. We provide assignments for the majority of the S{sub 1} and cation bands observed, and in particular we gain insight regarding a number of regions where vibrations are coupled via Fermi resonance. We also gain insight into intramolecular vibrational redistribution in this molecule.

Gardner, Adrian M.; Green, Alistair M.; Tamé-Reyes, Victor M.; Reid, Katharine L.; Davies, Julia A.; Parkes, Victoria H. K.; Wright, Timothy G., E-mail: Tim.Wright@nottingham.ac.uk [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

2014-03-21T23:59:59.000Z

246

Ovenized microelectromechanical system (MEMS) resonator  

DOE Patents [OSTI]

An ovenized micro-electro-mechanical system (MEMS) resonator including: a substantially thermally isolated mechanical resonator cavity; a mechanical oscillator coupled to the mechanical resonator cavity; and a heating element formed on the mechanical resonator cavity.

Olsson, Roy H; Wojciechowski, Kenneth; Kim, Bongsang

2014-03-11T23:59:59.000Z

247

Array combination for parallel imaging in Magnetic Resonance Imaging  

E-Print Network [OSTI]

Exdx? ? =? ??? null null nullnull [2.7] where ? is the sample conductivity. Substituting Eq. [2.5] into this, it is rewriting in terms of the magnetic vector potential, () () 2 sample V PAxAxd?? ? =? ??? null null null nullnull [2.8] Recalling that power... is also defined as 2 1 2 PIR= , [2.9] then () () 2 2 sample V R Ax Ax dx?? ? =? ??? null null null nullnull [2.10] assuming the magnetic vector potential, A null , is calculated using a unit current. The resistance of a conductive wire...

Spence, Dan Kenrick

2007-09-17T23:59:59.000Z

248

Image Charge Differential  

E-Print Network [OSTI]

Image Charge Differential Amplifier FT 0 Crude Oil Time (s) 543210 Frequency (kHz) m/z m q B f Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) uses the frequency of cyclotron motion of the ions in a static magnetic field to determine the mass-to-charge ratio, which is then used

Weston, Ken

249

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

250

ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. X, NO. X, JANUARY 2013 1 MRI-derived 3D-printed breast phantom for  

E-Print Network [OSTI]

ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. X, NO. X, JANUARY 2013 1 MRI-derived 3D-printed--We propose a 3D-printed breast phantom for use in pre-clinical experimental microwave imaging studies the procedure for generating the 3D-printed breast phantom and present the measured dielectric properties

Van Veen, Barry D.

251

Giant resonance decay  

SciTech Connect (OSTI)

Decay studies of giant multipole resonances are discussed, emphasizing the role of Coulomb excitation with intermediate energy heavy ions, which can provide very large cross sections for both isoscalar and isovector resonances. We discuss measurement of the photon decay of one and two phonon giant resonances, reporting results where available. It is pointed out throughout the presentation that the use of E1 photons as a tag'' provides a means to observe weakly excited resonances that cannot be observed in the singles spectra. 30 refs., 16 figs., 1 tab.

Beene, J.R.; Bertrand, F.E.

1990-01-01T23:59:59.000Z

252

Fast algorithms for nonconvex compression sensing: MRI reconstruction from very few data  

SciTech Connect (OSTI)

Compressive sensing is the reconstruction of sparse images or signals from very few samples, by means of solving a tractable optimization problem. In the context of MRI, this can allow reconstruction from many fewer k-space samples, thereby reducing scanning time. Previous work has shown that nonconvex optimization reduces still further the number of samples required for reconstruction, while still being tractable. In this work, we extend recent Fourier-based algorithms for convex optimization to the nonconvex setting, and obtain methods that combine the reconstruction abilities of previous nonconvex approaches with the computational speed of state-of-the-art convex methods.

Chartrand, Rick [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

253

E-Print Network 3.0 - acr bi-rads mri Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sciences Summary: Student Research Symposium: May 12, 2005 Fully Automated Quality Assurance for MRI involving ACR... for Use of the MR Phantom for the ACR MRI Accreditation...

254

MRI/TRUS data fusion for prostate brachytherapy. Preliminary results.  

E-Print Network [OSTI]

MRI/TRUS data fusion for prostate brachytherapy. Preliminary results. Christophe Reynier, Jocelyne suggests bringing the MR virtually in the operating room with MRI/TRUS data fusion. This involves providing at that time [2] and resulted in non-homogeneous irradiation where cold regions may have contributed

Paris-Sud XI, Université de

255

Helioseismology The Resonant Sun  

E-Print Network [OSTI]

Helioseismology The Resonant Sun Professor Bill Chaplin, School of Physics & Astronomy University Eddington #12;The Unseen Interior ''At first sight it would seem that the deep interior of the sun and stars;Overview What are resonant oscillations of the Sun? How do we observe the oscillations? What can we learn

256

Regarding Confinement Resonances  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

257

An integrated medical image database and retrieval system using a web application server  

Science Journals Connector (OSTI)

We developed an Integrated Medical Image Database and Retrieval System (INIS) for easy access by medical staff. The INIS mainly consisted of four parts: specific servers to save medical images from multi-vendor modalities of CT, MRI, CR, ECG and endoscopy; an integrated image database (DB) server to save various kinds of images in a DICOM format; a Web application server to connect clients to the integrated image DB and the Web browser terminals connected to an HIS system. The INIS provided a common screen design to retrieve CT, MRI, CR, endoscopic and ECG images, and radiological reports, which would allow doctors to retrieve radiological images and corresponding reports, or ECG images of a patient simultaneously on a screen. Doctors working in internal medicine on average accessed information 492 times a month. Doctors working in cardiological and gastroenterological accessed information 308 times a month. Using the INIS, medical staff could browse all or parts of a patient's medical images and reports.

Pengyu Cao; Masao Hashiba; Kouhei Akazawa; Tomoko Yamakawa; Takayuki Matsuto

2003-01-01T23:59:59.000Z

258

LABCOM resonator Phase 3  

SciTech Connect (OSTI)

The purpose of this project was to develop quartz crystal resonator designs, production processes, and test capabilities for 5-MHz, 6.2-MHz, and 10-MHz resonators for Tactical Miniature Crystal Oscillator (TMXO) applications. GE Neutron Devices (GEND) established and demonstrated the capability to produce and test quartz crystal resonators for use in the TMXO developed by the US Army ERADCOM (now LABCOM). The goals in this project were based on the ERADCOM statement of work. The scope of work indicated that the resonator production facilities for this project would not be completely independent, but that they would be supported in part by equipment and processes in place at GEND used in US Department of Energy (DOE) work. In addition, provisions for production test equipment or or eventual technology transfer costs to a commercial supplier were clearly excluded from the scope of work. The demonstrated technical capability of the deep-etched blank design is feasible and practical. It can be manufactured in quantity with reasonable yield, and its performance is readily predictable. The ceramic flatpack is a very strong package with excellent hermeticity. The four-point mount supports the crystal to reasonable shock levels and does not perturb the resonator's natural frequency-temperature behavior. The package can be sealed with excellent yields. The high-temperature, high-vacuum processing developed for the TMXO resonator, including bonding the piezoid to its mount with conductive polyimide adhesive, is consistent with precision resonator fabrication. 1 fig., 6 tabs.

Keres, L.J.

1990-11-01T23:59:59.000Z

259

Tunable multiwalled nanotube resonator  

DOE Patents [OSTI]

A tunable nanoscale resonator has potential applications in precise mass, force, position, and frequency measurement. One embodiment of this device consists of a specially prepared multiwalled carbon nanotube (MWNT) suspended between a metal electrode and a mobile, piezoelectrically controlled contact. By harnessing a unique telescoping ability of MWNTs, one may controllably slide an inner nanotube core from its outer nanotube casing, effectively changing its length and thereby changing the tuning of its resonance frequency. Resonant energy transfer may be used with a nanoresonator to detect molecules at a specific target oscillation frequency, without the use of a chemical label, to provide label-free chemical species detection.

Jensen, Kenneth J; Girit, Caglar O; Mickelson, William E; Zettl, Alexander K; Grossman, Jeffrey C

2013-11-05T23:59:59.000Z

260

Journal of Magnetism and Magnetic Materials 286 (2005) 324328 Light-free magnetic resonance force microscopy for studies of  

E-Print Network [OSTI]

Journal of Magnetism and Magnetic Materials 286 (2005) 324­328 Light-free magnetic resonance force for Physical Sciences, College Park, MD, USA Available online 4 November 2004 Abstract Magnetic resonance force microscopy is a scanned probe technique capable of three-dimensional magnetic resonance imaging. Its

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

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

262

Regarding Confinement Resonances  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

263

Regarding Confinement Resonances  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

264

Regarding Confinement Resonances  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

265

Resonant cryogenic chopper  

Science Journals Connector (OSTI)

We describe the design, construction, and performance of a resonant cryogenic chopper that operates at 4.2 K. The chopper is mechanically and thermally robust; it can occult a 2.54-cm...

Page, Lyman A; Cheng, Edward S; Meyer, Stephan S

1992-01-01T23:59:59.000Z

266

Micro-machined resonator  

DOE Patents [OSTI]

A micro-machined resonator, typically quartz, with upper and lower micro-machinable 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 electrode 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.

1993-03-30T23:59:59.000Z

267

Micro-machined resonator  

DOE Patents [OSTI]

A micro-machined resonator, typically quartz, with upper and lower micro-machinable 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 electrode 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, Ned A. (Albuquerque, NM); Koehler, Dale R. (Albuquerque, NM); Liang, Alan Y. (Albuquerque, NM); Smith, Bradley K. (Albuquerque, NM)

1993-01-01T23:59:59.000Z

268

PROTON RESONANCE SPECTROSCOPY  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for one resonance relatively strong isospin forbidden llo decay was observed. The thermonuclear reaction rates for the 28Si(a, PO)31p reaction were evaluated from the 31p(p,...

269

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

SciTech Connect (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

270

Injector with integrated resonator  

DOE Patents [OSTI]

The system may include a turbine engine. The turbine engine may include a fuel nozzle. The fuel nozzle may include an air path. The fuel nozzle may also include a fuel path such that the fuel nozzle is in communication with a combustion zone of the turbine engine. Furthermore, the fuel nozzle may include a resonator. The resonator may be disposed in the fuel nozzle directly adjacent to the combustion zone.

Johnson, Thomas Edward; Ziminsky, Willy Steve; York, William David; Stevenson, Christian Xavier

2014-07-29T23:59:59.000Z

271

Resonant dielectric metamaterials  

SciTech Connect (OSTI)

A resonant dielectric metamaterial comprises a first and a second set of dielectric scattering particles (e.g., spheres) having different permittivities arranged in a cubic array. The array can be an ordered or randomized array of particles. The resonant dielectric metamaterials are low-loss 3D isotropic materials with negative permittivity and permeability. Such isotropic double negative materials offer polarization and direction independent electromagnetic wave propagation.

Loui, Hung; Carroll, James; Clem, Paul G; Sinclair, Michael B

2014-12-02T23:59:59.000Z

272

106 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 29, NO. 1, JANUARY 2010 Feature Based Nonrigid Brain MR Image Registration  

E-Print Network [OSTI]

106 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 29, NO. 1, JANUARY 2010 Feature Based Nonrigid Brain MR Image Registration With Symmetric Alpha Stable Filters Shu Liao* and Albert C. S. Chung Abstract--A new feature based nonrigid image registration method for magnetic resonance (MR) brain images

Chung, Albert C. S.

273

128 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 25, NO. 1, JANUARY 2006 Unwrapping of MR Phase Images Using a  

E-Print Network [OSTI]

128 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 25, NO. 1, JANUARY 2006 Unwrapping of MR Phase of blood flow [1], [2]. Extracting the phase image from its measured complex MR image is nontrivial because, phase unwrapping. I. INTRODUCTION A. Background Magnetic resonance (MR) phase images often contain

Koetter, Ralf

274

Quantitative analysis of cerebral white matter anatomy from diffusion MRI  

E-Print Network [OSTI]

In this thesis we develop algorithms for quantitative analysis of white matter fiber tracts from diffusion MRI. The presented methods enable us to look at the variation of a diffusion measure along a fiber tract in a single ...

Maddah, Mahnaz

2008-01-01T23:59:59.000Z

275

RF power amplifier linearity compensation for MRI systems  

E-Print Network [OSTI]

In this thesis, a polar-feedback linearization system for use with MRI RF power amplifiers was designed and simulated. The design here presented is intended to replace Analogic's (located in Peabody, Massachusetts) ...

Torres Chico, Gabriel

2010-01-01T23:59:59.000Z

276

Split-ball resonator  

E-Print Network [OSTI]

We introduce a new concept of split-ball resonator and demonstrate a strong omnidirectional magnetic dipole response for both gold and silver spherical plasmonic nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole resonance throughout the visible spectral range is demonstrated by a change of the depth and width of the nanoscale cut. We realize this novel concept experimentally by employing the laser-induced transfer method to produce near-perfect spheres and helium ion beam milling to make cuts with the nanometer resolution. Due to high quality of the spherical particle shape, governed by strong surface tension forces during the laser transfer process, and the clean, straight side walls of the cut made by helium ion milling, magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. Structuring arbitrary features on the surface of ideal spherical resonators with nanoscale dimensions provides new ways of engineering hybrid resonant modes and ultra-high near-f...

Kuznetsov, Arseniy I; Fu, Yuan Hsing; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Kivshar, Yuri; Pickard, Daniel S; Lukiyanchuk, Boris

2014-01-01T23:59:59.000Z

277

LOS ALAMOS, New Mexico, July 31, 2008-Scientists from Los Alamos...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

applications as the transmission of electricity and electric motors for mass-transit trains. Superconducting magnets are currently used in Magnetic Resonance Imaging (MRI)...

278

E-Print Network 3.0 - anti-tumor agent tm208 Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: : vari- able anti-tumor effect on different tumor models, Bioelectrochem. Bioenerg. 35, 23-27, 1994. 21... with contrast-enhanced magnetic resonance imaging (MRI) using...

279

automated segmentation algorithm: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tumor Segmentation using two MRI Modalities Mohamed Ben Salah1 , Idanis Diaz1 automated brain tumor segmentation from only two magnetic resonance image modalities. The technique...

280

MagLab - Basic Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

fruits of Faradays discovery of electromagnetic induction. A more recent example is magnetic resonance imaging (MRI), which originated in basic research that started in the...

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

National High Magnetic Field Laboratory - Basic Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

fruits of Faraday's discovery of electromagnetic induction. A more recent example is magnetic resonance imaging (MRI), which originated in basic research that started in the...

282

Multifractal Detrended Fluctuation Analysis Shows Promise For Brain Tumor Grading  

Science Journals Connector (OSTI)

This work proposes a novel non-invasive method for brain tumor grading using magnetic resonance imaging (MRI). Multifractal Detrended Fluctuation Analysis (MFDFA) [1] provides features...

Reza, Syed; Mays, Randall; Iftekharuddin, Khan M

283

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

284

(Resonance ionization spectroscopy)  

SciTech Connect (OSTI)

J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

Young, J.P.

1990-10-11T23:59:59.000Z

285

Cyclotron Resonance in Gallium  

Science Journals Connector (OSTI)

Azbel'-Kaner cyclotron resonance has been studied at 36 and 9 Gc/sec at 1.2°K in the three principal symmetry planes of gallium with the microwave currents both parallel and perpendicular to the applied magnetic field. The resonance signals were characterized by extreme complexity and high resolution (long relaxation times). Mass values are determined as a function of orientation of the magnetic field in the sample surfaces. No interpretation of the mass branches on a model Fermi surface is attempted, but some correlations with previous de Haas-van Alphen data are presented.

T. W. Moore

1968-01-15T23:59:59.000Z

286

Method for resonant measurement  

DOE Patents [OSTI]

A method of measurement of objects to determine object flaws, Poisson's ratio (.sigma.) and shear modulus (.mu.) is shown and described. First, the frequency for expected degenerate responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of flaws in the object. Poisson's ratio and the shear modulus can be determined by identification of resonances dependent only on the shear modulus, and then using that shear modulus to find Poisson's ratio using other modes dependent on both the shear modulus and Poisson's ratio.

Rhodes, George W. (5201 Rio Grande Blvd., N.W., Albuquerque, NM 87107); Migliori, Albert (Rte. 4, Box 258 Tano Rd., Sante Fe, NM 87501); Dixon, Raymond D. (396 Connie Ave., White Rock, NM 87544)

1996-01-01T23:59:59.000Z

287

Multicavity X-Ray Fabry-Perot Resonance with Ultrahigh Resolution and Contrast  

Science Journals Connector (OSTI)

Realization of x-ray Fabry-Perot (FP) resonance in back-Bragg-reflection crystal cavities has been proposed and explored for many years, but to date no satisfactory performance has been achieved. Here we show that single-cavity crystal resonators intrinsically have limited finesse and efficiency. To break this limit, we demonstrate that monolithic multicavity resonators with equal-width cavities and specific plate thickness ratios can generate ultrahigh-resolution FP resonance with high efficiency, steep peak tails, and ultrahigh contrast simultaneously. The resonance mechanism is similar to that of sequentially cascaded single-cavity resonators. The ultranarrow-bandwidth FP resonance is anticipated to have various applications, including modern ultrahigh-resolution or precision x-ray monochromatization, spectroscopy, coherence purification, coherent diffraction, phase contrast imaging, etc.

X. R. Huang, D. P. Siddons, A. T. Macrander, R. W. Peng, and X. S. Wu

2012-05-31T23:59:59.000Z

288

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

289

E-Print Network 3.0 - alternative imaging modality Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: traditional imaging modalities such as magnetic resonance (MR), computed tomography (CT) and ultrasound (US... detection and characterization of breast cancer pathology...

290

Perpendicular fibre tracking for neural fibre bundle analysis using diffusion MRI  

Science Journals Connector (OSTI)

Information on the directionality and structure of axonal fibres in neural tissue can be obtained by analysing diffusion-weighted MRI data sets. Several fibre tracking algorithms have been presented in the literature that trace the underlying field of principal orientations of water diffusion, which correspond to the local primary eigenvectors of the diffusion tensor field. However, the majority of the existing techniques ignore the secondary and tertiary orientations of diffusion, which contain significant information on the local patterns of diffusion. In this paper, we introduce the idea of perpendicular fibre tracking and present a novel dynamic programming method that traces surfaces, which are locally perpendicular to the axonal fibres. This is achieved by using a cost function, with geometric and fibre orientation constraints, that is evaluated dynamically for every voxel in the image domain starting from a given seed point. The proposed method is tested using synthetic and real DW-MRI data sets. The results conclusively demonstrate the accuracy and effectiveness of our method.

S. Ray; W. O'Dell; Angelos Barmpoutis

2014-01-01T23:59:59.000Z

291

Figure 1. Depiction of the BrainAGE concept. [Image modified from [1], with permission from Hogrefe Publishing, Bern.] (A) The model of healthy brain aging is trained with the chronological age and preprocessed structural MRI data of a training sample (le  

E-Print Network [OSTI]

Figure 1. Depiction of the BrainAGE concept. [Image modified from [1], with permission from Hogrefe Publishing, Bern.] (A) The model of healthy brain aging is trained with the chronological age important voxel locations that were used by the age regression model). Subsequently, the individual brain

Gaser, Christian

292

PROTON RESONANCE SPECTROSCOPY  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

28Si was studied from E 3.0 to 3.75 MeV. A resonance not previously seen in the elas- p tic scattering channel was observed at E 2.287 MeV; the elastic width was measured to p be...

293

Resonant scattering of surface plasmon polaritons by dressed quantum dots  

SciTech Connect (OSTI)

The resonant scattering of surface plasmon-polariton waves (SPP) by embedded semiconductor quantum dots above the dielectric/metal interface is explored in the strong-coupling regime. In contrast to non-resonant scattering by a localized dielectric surface defect, a strong resonant peak in the spectrum of the scattered field is predicted that is accompanied by two side valleys. The peak height depends nonlinearly on the amplitude of SPP waves, reflecting the feedback dynamics from a photon-dressed electron-hole plasma inside the quantum dots. This unique behavior in the scattered field peak strength is correlated with the occurrence of a resonant dip in the absorption spectrum of SPP waves due to the interband photon-dressing effect. Our result on the scattering of SPP waves may be experimentally observable and applied to spatially selective illumination and imaging of individual molecules.

Huang, Danhong; Cardimona, Dave [Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117 (United States); Easter, Michelle [Department of Mechanical Engineering, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, New Jersey 07030 (United States); Gumbs, Godfrey [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065 (United States); Maradudin, A. A. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Lin, Shawn-Yu [Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States); Zhang, Xiang [Department of Mechanical Engineering, 3112 Etcheverry Hall, University of California at Berkeley, Berkeley, California 94720 (United States)

2014-06-23T23:59:59.000Z

294

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

295

SQUID-Detected MRI in the Limit of Zero Static Field  

SciTech Connect (OSTI)

This thesis describes an implementation of the so-called"zero-field MRI" (ZFMRI) pulse sequence, which allows for imaging in an arbitrarily low B(0) field. The ZFMRI sequence created an effective unidirectional gradient field by using a train of pi pulses to average out the concomitant gradient components during encoding. The signals were acquired using a low-transition temperature dc Superconducting QUantum Interference Device (low-Tc dc SQUID) coupled to a first-order axial gradiometer. The experiments were carried out in a liquid helium dewar which was magnetically shielded with a single-layer mu-metal can around the outside and a superconducting Pb can contained within the helium space. We increased the filling factor of the custom-made, double-walled Pyrex insert by placing the liquid alcohol sample, at a temperature of approximately -50 degrees C, at the center of one loop of the superconducting gradiometer, which was immersed in the helium bath.

Kelso, Nathan Dean

2009-12-14T23:59:59.000Z

296

Changes in MRI signal intensity during hypercapnic challenge under conscious and anesthetized conditions  

E-Print Network [OSTI]

Changes in MRI signal intensity during hypercapnic challenge under conscious and anesthetized were exposed to different concentrations of carbon dioxide (CO2) while conscious and anesthetized. Hypercapnia produced significantly greater increases in MRI signal intensity in fully conscious animals (6

Duong, Timothy Q.

297

E-Print Network 3.0 - abnormal brain mri Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Powered by Explorit Topic List Advanced Search Sample search results for: abnormal brain mri Page: << < 1 2 3 4 5 > >> 1 SILENT MRI WHITE MATTER LESIONS IN PATIENTS WITH CIS...

298

E-Print Network 3.0 - abnormal 3-d mri Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

policy or requirements regarding clinical evaluation of research MRI studies, Summary: : 3D T1 Axial EPI 12;The limited set of sequences used for a research MRI study is...

299

Direct visualization of the perforant pathway in the human brain with ex vivo diffusion tensor imaging  

E-Print Network [OSTI]

Ex vivo magnetic resonance imaging yields high resolution images that reveal detailed cerebral anatomy and explicit cytoarchitecture in the cerebral cortex, subcortical structures, and white matter in the human brain. Our ...

Augustinack, Jean C.

300

Cyclotron Resonance in Cadmium  

Science Journals Connector (OSTI)

Extensive observations at 1.5°K and both 23.8 Gc/sec and 74.2 Gc/sec of cyclotron-resonance phenomena in cadmium are reported. One group of experiments is done with the steady applied field parallel to the sample plane (Azbel'-Kaner geometry). A large number of signals are observed, only some of which are sufficiently reliable to identify with cyclotron masses. All the masses are plotted versus the crystallographic orientation of the steady applied field in three of the principal planes. The reliable, well resolved signals are identified and associated tentatively with orbits. Most of these orbits are consistent with the current model of the Fermi surface of cadmium, but some of them require small modifications of it. These orbits are either on the "pillow" or on the large surface associated with holes in the second band. The masses observed with the magnetic field parallel to the sample plane are all too large to identify plausibly with the smaller pieces of the Fermi surface such as the "butterflies" and "cigars". It is suggested that the resonances associated with the charge carriers of smaller mass are lost in the signals from harmonics of those of larger mass. In another group of experiments, data have been obtained with the steady applied field normal to the sample surface. Here signals are obtained at classical cyclotron-resonance fields equal to those observed in the other geometry although the signals are in the anomalous-skin-effect regime and the much larger effects associated with Doppler-shifted cyclotron resonance are at magnetic fields too high to be observed. A theoretical treatment and a discussion of the physics of these effects is given. In this geometry, a cyclotron mass of approximately 0.22 m0 is also observed. The related orbit is only tentatively identified, but it is definitely thought to involve one of the smaller pieces of the Fermi surface.

J. K. Galt; F. R. Merritt; J. R. Klauder

1965-08-02T23:59:59.000Z

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.


301

Musculoskeletal simulation model generation from MRI datasets and motion capture data  

E-Print Network [OSTI]

Musculoskeletal simulation model generation from MRI datasets and motion capture data Jérôme Schmid

Paris-Sud XI, Université de

302

Technical Note Finger motion sensors for fMRI motor studies  

E-Print Network [OSTI]

Technical Note Finger motion sensors for fMRI motor studies Judith D. Schaechter,a,b,* Christopher was not affected by the high static magnetic field (3 T). Increasing the RF power transmitted during fMRI by using monitoring during the fMRI exper- iment allows for crude assessment of whether the subject performed

Schaechter, Judith D.

303

Difficulties of T1 brain MRI segmentation techniques M S. Atkins*a  

E-Print Network [OSTI]

: brain segmentation, T1-head MRI, IBSR data 1. INTRODUCTION We are interested in segmenting the brain in T1-weighted head scans to find the perimeter of the brain cortex, which is useful for functional MRI , is an automatic brain segmentation algorithm for MRI head scans. In the algorithm, a lower intensity threshold, t2

Orchard, Jeffery J.

304

Tiny images  

E-Print Network [OSTI]

The human visual system is remarkably tolerant to degradations in image resolution: in a scene recognition task, human performance is similar whether $32 \\times 32$ color images or multi-mega pixel images are used. With ...

Torralba, Antonio

2007-04-23T23:59:59.000Z

305

IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 27, NO. 8, AUGUST 2008 1095 Automatic Detection of Regional Heart Rejection  

E-Print Network [OSTI]

of Regional Heart Rejection in USPIO-Enhanced MRI Hsun-Hsien Chang, Member, IEEE, José M. F. Moura*, Fellow. When a transplanted heart undergoes rejection, immune cells will infiltrate the allograft. Imaged by 2 in the image facilitates the identifi- cation of acute heart rejection. This paper develops a classifier

Moura, José

306

Cyclotron resonant interactions in cosmic particle accelerators  

E-Print Network [OSTI]

A review is given for cyclotron resonant interactions in space plasmas. After giving a simple formulation for the test particle approach, illustrative examples for resonant interactions are given. It is shown that for obliquely propagating whistler waves, not only fundamental cyclotron resonance, but also other resonances, such as transit-time resonance, anomalous cyclotron resonance, higher-harmonic cyclotron resonance, and even subharmonic resonance can come into play. A few recent topics of cyclotron resonant interactions, such as electron injection in shocks, cyclotron resonant heating of solar wind heavy ions, and relativistic modifications, are also reviewed.

Terasawa, T; 10.1007/s11214-012-9878-0

2012-01-01T23:59:59.000Z

307

Nanotube resonator devices  

DOE Patents [OSTI]

A fully-functional radio receiver fabricated from a single nanotube is being disclosed. Simultaneously, a single nanotube can perform the functions of all major components of a radio: antenna, tunable band-pass filter, amplifier, and demodulator. A DC voltage source, as supplied by a battery, can power the radio. Using carrier waves in the commercially relevant 40-400 MHz range and both frequency and amplitude modulation techniques, successful music and voice reception has been demonstrated. Also disclosed are a radio transmitter and a mass sensor using a nanotube resonator device.

Jensen, Kenneth J; Zettl, Alexander K; Weldon, Jeffrey A

2014-05-06T23:59:59.000Z

308

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

309

Fano resonances in nanoscale structures  

SciTech Connect (OSTI)

Modern nanotechnology allows one to scale down various important devices (sensors, chips, fibers, etc.) and thus opens up new horizons for their applications. The efficiency of most of them is based on fundamental physical phenomena, such as transport of wave excitations and resonances. Short propagation distances make phase-coherent processes of waves important. Often the scattering of waves involves propagation along different paths and, as a consequence, results in interference phenomena, where constructive interference corresponds to resonant enhancement and destructive interference to resonant suppression of the transmission. Recently, a variety of experimental and theoretical work has revealed such patterns in different physical settings. The purpose of this review is to relate resonant scattering to Fano resonances, known from atomic physics. One of the main features of the Fano resonance is its asymmetric line profile. The asymmetry originates from a close coexistence of resonant transmission and resonant reflection and can be reduced to the interaction of a discrete (localized) state with a continuum of propagation modes. The basic concepts of Fano resonances are introduced, their geometrical and/or dynamical origin are explained, and theoretical and experimental studies of light propagation in photonic devices, charge transport through quantum dots, plasmon scattering in Josephson-junction networks, and matter-wave scattering in ultracold atom systems, among others are reviewed.

Miroshnichenko, Andrey E.; Flach, Sergej; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia); Max-Planck-Institut fuer Physik Komplexer Systeme, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

2010-07-15T23:59:59.000Z

310

Cyclotron Resonance in Bilayer Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resonance in Bilayer Graphene PI: Horst Stormer, Department of Physics, Columbia University Supported by NSF (DMR-03-52738 and CHE-0117752), ONR (N000150610138) DOE...

311

Electromagnetic production of hyperon resonances  

E-Print Network [OSTI]

The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the $\\Lambda(1405)$ resonance; a strong suggestion of meson cloud effects in the structure of the $\\Sigma(1385)$ resonance; data from $K^*$ photoproduction that will test the existence of the purported $K_0(800)$ meson. Properties of other hyperon resonances will also be studied in the near future.

K. Hicks; D. Keller; W. Tang

2010-12-14T23:59:59.000Z

312

RESEARCH ARTICLE Shared and Idiosyncratic Cortical Activation Patterns in Autism  

E-Print Network [OSTI]

: autism; inter-subject correlation; functional magnetic resonance imaging (fMRI); hyperconnectivity regions, the amygdala, hippocampus, caudate nucleus and cerebellum [Amaral, Schumann, & Nordahl, 2008-life circumstances, we used functional magnetic resonance imaging (fMRI) to map the whole- brain activation profile

Hasson, Uri

313

Use of Yb(III) Centered Near Infra-Red (NIR) Luminescence to Determine the Hydration State of a 3,2-HOPO based MRI-Contrast Agent  

SciTech Connect (OSTI)

It has been more than a decade since the first reports of [Gd(Tren-Me-3,2-HOPO)(H{sub 2}O){sub 2}] as a potential new class of magnetic resonance imaging contrast agent (MRI-CA). The defining feature of these 1-methyl-3-hydroxypyridin-2-one (Me-3,2-HOPO) based compounds has been the use of a hexadentate ligand design, and hence an increase in the number of metal bound water molecules, without sacrificing complex stability compared to the typically octadentate contrast agents used commercially. Since that time, significant advances in the properties of these chelates have been steadily reported, including improvements in relaxivity, incorporation into macromolecular architectures and, recently, the first direct verification of solution structure using the discovery of Eu(III) centered luminescence with the isomeric 1-hydroxypyridin-2-one (1,2-HOPO) chelate as a sensitizing chromophore. Nonetheless, it has remained frustrating that direct measurements of the inner sphere hydration state, q, using luminescence techniques with the parent Me-3,2-HOPO compounds have remained elusive, even when direct laser excitation of weakly absorbing f-f transitions were employed (eg. for Eu(III) complexes). This failing can likely be traced to the presence of a low lying LMCT state which efficiently quenches metal based emission. Instead, estimates of the q and hence solution structure have relied on the fitting of relaxivity data to the Solomon-Bloembergen-Morgan equations or, where sufficiently soluble in aqueous solution, studies on the temperature dependence of the paramagnetic contribution to the water {sup 17}O NMR transverse relaxation rate. Recently, Beeby et al reported on a qualitative equation to determine inner sphere hydration based on the change in lifetimes for Yb(III) in going from H{sub 2}O to D{sub 2}O solution, and we reasoned that the lower energy accepting state of Yb(III) may lie below the LMCT state which quenches Eu(III) emission, and hence may facilitate sensitized emission from Yb(III). This hypothesis was borne out experimentally, and herein we describe for the first time sensitized luminescence in the Near Infra-Red (NIR) region from a [Yb(Tren-Me-3,2-HOPO)(H{sub 2}O){sub 2}] complex, and hence the direct measurement of q for the archetypical member of this family of compounds.

Moore, Evan G.; Seitz, Michael; Raymond, Kenneth N.

2008-06-09T23:59:59.000Z

314

Ferromagnetic resonance in $\\epsilon$-Co magnetic composites  

E-Print Network [OSTI]

We investigate the electromagnetic properties of assemblies of nanoscale $\\epsilon$-cobalt crystals with size range between 5 nm to 35 nm, embedded in a polystyrene (PS) matrix, at microwave (1-12 GHz) frequencies. We investigate the samples by transmission electron microscopy (TEM) imaging, demonstrating that the particles aggregate and form chains and clusters. By using a broadband coaxial-line method, we extract the magnetic permeability in the frequency range from 1 to 12 GHz, and we study the shift of the ferromagnetic resonance with respect to an externally applied magnetic field. We find that the zero-magnetic field ferromagnetic resonant peak shifts towards higher frequencies at finite magnetic fields, and the magnitude of complex permeability is reduced. At fields larger than 2.5 kOe the resonant frequency changes linearly with the applied magnetic field, demonstrating the transition to a state in which the nanoparticles become dynamically decoupled. In this regime, the particles inside clusters can ...

Chalapat, Khattiya; Huuppola, Maija; Koponen, Lari; Johans, Christoffer; Ras, Robin H A; Ikkala, Olli; Oksanen, Markku A; Seppälä, Eira; Paraoanu, G S

2014-01-01T23:59:59.000Z

315

Giant resonances in Mg-24  

E-Print Network [OSTI]

The giant resonance region in Mg-24 was studied with inelastic scattering of 240 MeV alpha particles at small angles including 0 degrees. The giant resonance peak was found to extend up to E-X = 41 MeV. Isoscalar E0, E1, and E2 strength...

Youngblood, David H.; Lui, YW; Clark, HL.

1999-01-01T23:59:59.000Z

316

Baryon Spectroscopy and Resonances  

SciTech Connect (OSTI)

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

317

Argonne CNM Highlight: Nanomechanical Resonator Self-Assembled from  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

318

Nuclear-resonant electron scattering  

Science Journals Connector (OSTI)

We investigate nuclear-resonant electron scattering as occurring in the two-step process of nuclear excitation by electron capture (NEEC) followed by internal conversion. The nuclear excitation and decay are treated by a phenomenological collective model in which nuclear states and transition probabilities are described by experimental parameters. We present capture rates and resonant strengths for a number of heavy-ion collision systems considering various scenarios for the resonant electron-scattering process. The results show that for certain cases resonant electron scattering can have significantly larger resonance strengths than NEEC followed by the radiative decay of the nucleus. We discuss the impact of our findings on the possible experimental observation of NEEC.

Adriana Pálffy and Zoltán Harman

2008-04-04T23:59:59.000Z

319

Multivoxel Magnetic Resonance Spectroscopy of Brain Tumors  

Science Journals Connector (OSTI)

...reprints should be addressed, Magnetic Resonance Science Center, Box 1290, 1 Irving...Francisco, CA 94143-1290 Magnetic Resonance Science Center, University of...failure of new treatments. | Magnetic Resonance Science Center, University of...

Sarah J. Nelson

2003-05-01T23:59:59.000Z

320

Nuclear magnetic resonance quantum information processing  

Science Journals Connector (OSTI)

...Ivan S. Oliveira and Roberto M. Serra Nuclear magnetic resonance quantum information...and experiment . For the past decade, nuclear magnetic resonance (NMR) has been established...anticipate the contents of this issue. nuclear magnetic resonance|quantum information...

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.


321

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

322

Subwavelength edge detection through trapped resonances in waveguides  

E-Print Network [OSTI]

Lenses that can collect the perfect image of an object must restore propagative and evanescent waves. However, for efficient information transfer, e.g., in compressed sensing, it is often desirable to detect only the fast spatial variations of the wave field (carried by evanescent waves), as the one created by edges or small details. Image processing edge detection algorithms perform such operation but they add time and complexity to the imaging process. Here, we present a new subwavelength approach that generates an image of only those components of the acoustic field that are equal to or smaller than the operating wavelength. The proposed technique converts evanescent waves into propagative waves exciting trapped resonances in a waveguide, and it uses periodicity to attenuate the propagative components. This approach achieves resolutions about an order of magnitude smaller than the operating wavelength and makes it possible to visualize independently edges aligned along different directions.

Molerón, Miguel

2015-01-01T23:59:59.000Z

323

Electron resonances in alkali-metal overlayers on metals  

Science Journals Connector (OSTI)

Based on a jellium model using a self-consistent potential modified to an image-potential shape outside the surface of Na and Cs monolayers on Al(111), we have identified resonances in the overlayer-induced density of electron states. This jellium-model description of the electronic structure is supported by the good agreement between the calculated energy for the lowest unoccupied level and the observed energy by inverse photoemission for (2×2)Na on Al(111).

Lars-Allan Salmi and Mats Persson

1989-03-15T23:59:59.000Z

324

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

325

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

326

Advanced Magnetic Resonance Workshop Report | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetic Resonance Workshop Report Advanced Magnetic Resonance Workshop Report NMR and EPR Workshop: Mueller KT, Washton NM, Pruski M, Lipton AS. 2013. "Science Drivers and...

327

New Tools for Chemically Directed Glycoproteomics and Xe-based MRI Contrast Agents  

E-Print Network [OSTI]

of magnetic and semi- conducting nanowires. Science 303,magnetic resonance hyperpolarized biosensor. Science 314,magnetic resonance hyperpolarized biosensor. Science 314,

Palaniappan, Krishnan K.

2012-01-01T23:59:59.000Z

328

People Images  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Images People Images Several hundred of the 1700 U.S. scientists contributing to the LHC accelerator and experiments gathered in June 2008 in CERN's building 40 CE0252 Joel...

329

Resonant relaxation in protoplanetary disks  

E-Print Network [OSTI]

Resonant relaxation is a novel form of two-body relaxation that arises in nearly Keplerian disks such as protoplanetary disks. Resonant relaxation does not affect the semimajor axes of the particles, but enhances relaxation of particle eccentricities and inclinations. The equilibrium state after resonant relaxation is a Rayleigh distribution, with the mean-square eccentricity and inclination inversely proportional to mass. The rate of resonant relaxation depends strongly on the precession rate of the disk. If the precession due to the disk's self-gravity is small compared to the total precession, then the relaxation is concentrated near the secular resonance between each pair of interacting bodies; on the other hand if the precession rate is dominated by the disk's self-gravity then relaxation occurs through coupling to the large-scale low-frequency m=1 normal modes of the disk. Depending on the disk properties, resonant relaxation may be either stronger or weaker than the usual non-resonant relaxation.

Scott Tremaine

1998-05-27T23:59:59.000Z

330

Heart-induced movements in the thorax as detected by MRI  

E-Print Network [OSTI]

In order to provide information for the use of radar in diagnostics a qualitative map of movements in the thorax has been obtained. This map was based on magnetic resonance image sequences of a human thorax during suspended respiration. The movements were measured using two distinct techniques. Segmentation provided measures of aorta dilatation and displacements, and image edge detection indicated other movements. The largest heart movements were found in the anterior and left regions of the heart with in-plane displacements on the order of 1 cm and which caused lung vessels displacements on the order of 2-3mm especially on the left side due to the heart ventricular. Mechanical coupling between the heart and aorta caused aorta displacements and shape distortions. Despite this coupling, aorta dilatations most likely reflected blood pressure variations.

Solberg, Lars Erik; Fosse, Erik; Hol, Per Kristian

2014-01-01T23:59:59.000Z

331

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

332

Tunable and angle-insensitive plasmon resonances in graphene ribbon arrays with multispectral diffraction response  

SciTech Connect (OSTI)

Plasmon resonances in graphene ribbon arrays are investigated numerically by means of the Finite Element Method. Numerical analysis shows that a series of multipolar resonances take place when graphene ribbon arrays are illuminated by a TM polarized electromagnetic wave. Moreover, these resonances are angle-independent, and can be tuned greatly by the width and the doping level of the graphene ribbons. Specifically, we demonstrate that for graphene arrays with several sets of graphene ribbons, which have different widths or doping levels, each of these multipolar resonances will be split into several ones. In addition, as plasmon resonances can confine electromagnetic field at the ribbon edges, graphene ribbons with different widths or doping levels offer intriguing application for electrically tunable spectral imaging.

Li, Kangwen; Ma, Xunpeng; Zhang, Zuyin; Xu, Yun, E-mail: xuyun@semi.ac.cn; Song, Guofeng [Institute of Semiconductors, Chinese Academy of Sciences, Beijing (China)

2014-03-14T23:59:59.000Z

333

E-Print Network 3.0 - accelerated cardiac mri Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

tracking of the heart in cardiac MRI. In 2nd International ... Source: Rouchdy, Youssef - Instrumentation, Control and Architecture of Advanced Robots, INRIA Sophia Antipolis...

334

E-Print Network 3.0 - active mri implants Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

interested in participating Summary: while lying inside the MRI scanner as your brain activity is being monitored 2hrs. 1 Computer Studies 2... brains process certain...

335

Baryon Resonances Observed at BES  

E-Print Network [OSTI]

The $\\psi$ decays provide a novel way to explore baryon spectroscopy and baryon structure. The baryon resonances observed from $\\psi$ decays at BES are reviewed. The implications and prospects at upgraded BESIII/BEPCII are discussed.

B. S. Zou

2008-02-01T23:59:59.000Z

336

Resonant Raman spectroscopy of nanotubes  

Science Journals Connector (OSTI)

...Raman spectroscopy in carbons: from nanotubes to diamond compiled by Andrea C. Ferrari...Robertson Resonant Raman spectroscopy of nanotubes Christian Thomsen 1 Stephanie Reich 2...The experimental situation in carbon nanotubes is reviewed in view of these criteria...

2004-01-01T23:59:59.000Z

337

Nuclear magnetic resonance readable sensors  

E-Print Network [OSTI]

The monitoring of physiological biomarkers is fundamental to the diagnosis and treatment of disease. We describe here the development of molecular sensors which can be read by magnetic resonance (MR) relaxometry. MR is an ...

Ling, Yibo

2010-01-01T23:59:59.000Z

338

Dynamical generation of pseudoscalar resonances  

SciTech Connect (OSTI)

We study the interactions between the f{sub 0}(980) and a{sub 0}(980) scalar resonances and the lightest pseudoscalar mesons. We first obtain the elementary interaction amplitudes, or interacting kernels, without including any ad hoc free parameter. This is achieved by using previous results on the nature of the lightest scalar resonances as dynamically generated from the rescattering of S-wave two-meson pairs. Afterwards, the interaction kernels are unitarized and the final S-wave amplitudes result. We find that these interactions are very rich and generate a large amount of pseudoscalar resonances that could be associated with the K(1460), {pi}(1300), {pi}(1800), {eta}(1475), and X(1835). We also consider the exotic channels with isospin 3/2 and 1, the latter having positive G-parity. The former could also be resonant in agreement with a previous prediction.

Albaladejo, M.; Oller, J. A.; Roca, L. [Departamento de Fisica, Universidad de Murcia, E-30071 Murcia (Spain)

2010-11-01T23:59:59.000Z

339

Cover image Darwin and physics? The relevance  

E-Print Network [OSTI]

CharlesSantoriandYoshihisaYamamoto 174 Nuclear magnetic resonance: The benefits of travel Alison.C.Glattli,M.-S.Choi,C.MoraandT.Kontos N&Vp175 213 imaging nanoscale Fermi-surface variations in an inhomogeneous superconductor W.D.Wise

Loss, Daniel

340

Wavelet smoothing of functional magnetic resonance images: A ...  

E-Print Network [OSTI]

and these choices, among other things, concern us in this paper. ... shows the active pixels in white (with a pixel value of 1) and the inactive pixels in black (with a value of 0). ... We dealt with the boundaries in the final (time) dimension.

1910-30-72T23:59:59.000Z

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

On the dynamics of magnetic fluids in magnetic resonance imaging  

E-Print Network [OSTI]

The hydrodynamics of magnetic fluids, often termed ferrofluids, has been an active area of research since the mid 1960s. However, it is only in the past twenty years that these fluids have begun to be used in magnetic ...

Cantillon-Murphy, Pádraig J

2008-01-01T23:59:59.000Z

342

SUPPLEMENTAL MATERIAL I: SEM IMAGE OF PHOTONIC CRYSTAL RESONATOR  

E-Print Network [OSTI]

notable difference: the use of e-beam evaporated silicon oxide as the nanotaper cladding in place of SU-8. A tunable infrared laser was connected to a tapered fibre lens via an erbium-doped-fibre-amplifier (EDFA

Erickson, David

343

SQUID-Detected Magnetic Resonance Imaging in Microtesla Fields  

E-Print Network [OSTI]

quantization (30). In a Josephson junction, Cooper pairs ofconsists of two Josephson junctions connected in parallel onis the array of 20 Josephson junctions in series with the

Moessle, Michael; Hatridge, Michael; Clarke, John

2008-01-01T23:59:59.000Z

344

Postinfectious Encephalitis A Coregistered SPECT and Magnetic Resonance Imaging  

E-Print Network [OSTI]

-mail: eitti@humc.edu From the Departments of Radiology,* Pediatric Neurology, and Pathology, Harbor

Itti, Laurent

345

Compressed Sensing accelerated radial acquisitions for dynamic Magnetic Resonance Imaging.  

E-Print Network [OSTI]

??We present a flexible method dubbed Accelerated Radial Compressed Sensing (ARCS) which uses Compressed Sensing to reconstruct 2D and 3D radial data. Our tests on… (more)

Zwaan, I.N.

2013-01-01T23:59:59.000Z

346

Fasciculography: Volumetric Tract Parcellation from Diffusion Magnetic Resonance Images  

E-Print Network [OSTI]

for the advice, encouragement and support on professional de- velopment: Beth Bennett, Pengcheng Shi and Chi

Duncan, James S.

347

Impurity resonances in carbon nanotubes  

Science Journals Connector (OSTI)

Analytical expressions are derived for the self-energies of electrons in carbon nanotubes while interacting with impurity atoms. Results are reported for armchair and zigzag tubes. It is shown that the impurity causes a bound electron donor or acceptor state beneath every semiconductor band edge. If the tubes are metallic, these bound states become resonance states. The analytical formulas give resonance shapes in good agreement with former numerical calculations.

G. D. Mahan

2004-03-17T23:59:59.000Z

348

Recoilless Resonant Capture of Antineutrinos  

E-Print Network [OSTI]

Resonant capture of antineutrinos can be accomplished by exploiting the monoenergetic antineutrinos emitted in bound state beta-decay. Extending this idea, I explore conditions for recoilless resonant capture in the system 3H - 3He. Observation of such transitions can set the stage for placing stringent limits on the neutrino parameter theta-13 on an ultra-short baseline of ~9 m and for observing the gravitational red shift of neutrinos

R. S. Raghavan

2005-11-15T23:59:59.000Z

349

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

350

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

351

Does the ?(3, 3) resonance factorize?  

Science Journals Connector (OSTI)

Evidence is presented showing that there are nonresonant coherent backgrounds interfering with ?(3, 3) resonance production in both ?N elastic scattering and photoproduction. The background in each case is predominantly given by the Born term projected into the resonant channel. Interplay between background and direct resonance production results in the observed shifts in the resonant-cross-section peaks.

M. G. Olsson

1976-05-01T23:59:59.000Z

352

An active learning approach to the physics of medical imaging  

Science Journals Connector (OSTI)

This paper describes an experimentally oriented medical imaging course where the students record, process and analyse 3D data of an unknown piece of formalin fixed porcine tissue hidden in agar in order to estimate the tissue types present in a selected 2D slice. The recorded planar X-ray, CT, MRI, ultrasound and SPECT images show the tissue in very different ways. The students can only estimate the tissue type by studying the physical principles of the imaging modalities. The true answer is later revealed by anatomical photographs obtained from physical slicing. The paper describes the phantoms and methods used in the course. Sample images recorded with the different imaging modalities are provided. Challenges faced by the students are outlined. Results of the course show high increase in competencies as judged from graded reports, low course drop-out rate, high pass-rate at the exam, high student participation and large student satisfaction.

Jens E. Wilhjelm; Michael Johannes Pihl; Markus Nowak Lonsdale; Mikael Jensen

2008-01-01T23:59:59.000Z

353

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

354

Damien J. Mannion University of Sydney, Australia  

E-Print Network [OSTI]

visual system. Using functional magnetic resonance imaging (fMRI), we have previously shown of natural images aligned to the gaze of a freely-moving human observer (Schumann, Einhäuser, Vockeroth

König, Peter

355

Columbia University Varying Electron Cyclotron ResonanceVarying Electron Cyclotron Resonance  

E-Print Network [OSTI]

currently via two electron cyclotron resonance heating (ECRH) sources: 2.5 kW at 2.45 GHz and 2.5 kW at 6 and heated via electron cyclotron resonance heating (ECRH).electron cyclotron resonance heating (ECRHColumbia University Varying Electron Cyclotron ResonanceVarying Electron Cyclotron Resonance

356

Image Resources  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

357

EMSL - Imaging  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

imaging en Diffusional Motion of Redox Centers in Carbonate Electrolytes . http:www.emsl.pnl.govemslwebpublicationsdiffusional-motion-redox-centers-carbonate-electrolytes

358

Angular dependence of Dicke-narrowed electromagnetically induced transparency resonances  

SciTech Connect (OSTI)

Dicke narrowing is a phenomenon that dramatically reduces the Doppler width of spectral lines, due to frequent velocity-changing collisions. A similar phenomenon occurs for electromagnetically induced transparency (EIT) resonances, and facilitates ultranarrow spectral features in room-temperature vapor. We directly measure the Dicke-like narrowing by studying EIT line shapes as a function of the angle between the pump and probe beams. The measurements are in good agreement with an analytic theory with no fit parameters. The results show that Dicke narrowing can increase substantially the tolerance of hot-vapor EIT to angular deviations. We demonstrate the importance of this effect for applications such as imaging and spatial solitons using a single-shot imaging experiment, and discuss the implications for the feasibility of storing images in atomic vapor.

Shuker, M.; Firstenberg, O.; Ben-Kish, A.; Ron, A. [Department of Physics, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Pugatch, R.; Davidson, N. [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)

2007-08-15T23:59:59.000Z

359

Differential MRI analysis for quantification of low grade glioma growth Elsa D. Angelini a,  

E-Print Network [OSTI]

to a common range of gray levels via a midway-based histogram mapping. This mapping enabled direct comparison distributions in midway-mapped MRI volumes as well as in their difference maps was designed to identify estimations, were proposed. The influence and modeling of MRI inhomogeneity field on a novel midway

360

CONTRAST MAPPING AND STATISTICAL TESTING FOR LOW-GRADE GLIOMA GROWTH QUANTIFICATION ON BRAIN MRI  

E-Print Network [OSTI]

MRI volumes is proposed, based on difference maps af- ter non-linear contrast midway mapping applications: (1) change detection from a statistical test on differences in midway-mapped MRI data, and (2 growth measurement methods, independent of sequential tumor segmentation. 2. METHOD 2.1. Midway Mapping 2

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

Deconvolution of Impulse Response in Event-Related BOLD fMRI1 Gary H. Glover  

E-Print Network [OSTI]

Deconvolution of Impulse Response in Event-Related BOLD fMRI1 Gary H. Glover Center for Advanced MR). Unfortunately, the fMRI signal is heavily filtered by the hemodynamic delay inherent in the blood oxygen level-dependent (BOLD) contrast mechanism (Buxton et al., 1997), and therefore temporally evolving events are blurred

Glover, Gary H.

362

Predicting Brain States from fMRI Data: Incremental Functional Principal Component  

E-Print Network [OSTI]

Predicting Brain States from fMRI Data: Incremental Functional Principal Component Regression S@science.uva.nl Abstract We propose a method for reconstruction of human brain states directly from func- tionalMRI data to the domain of stochastic functional measurements, facilitating evaluation of brain responses

Smeulders, Arnold

363

Predictive Modeling of fMRI Brain States using Functional Canonical Correlation Analysis  

E-Print Network [OSTI]

Predictive Modeling of fMRI Brain States using Functional Canonical Correlation Analysis S Abstract. We present a novel method for predictive modeling of human brain states from functional for prediction of naturalistic stimuli from unknown fMRI data shows that the method nds highly predictive brain

Smeulders, Arnold

364

The effects of humming and pitch on craniofacial and craniocervical morphology measured using MRI  

E-Print Network [OSTI]

The effects of humming and pitch on craniofacial and craniocervical morphology measured using MRI, pitch-related contributions are inseparable from those due to articulator input. In humming, articulator input is negligible. Using MRI we test the hypothesis that voice production is accompanied by pitch

Levi, Ran

365

Automatic Scan Prescription for Brain MRI T. Ernst, L. Itti, L. Chang  

E-Print Network [OSTI]

Automatic Scan Prescription for Brain MRI T. Ernst, L. Itti, L. Chang Harbor-UCLA Medical Center that allows the automatic prescription of brain MRI scans. This involves determination of the orientation of the current patient's brain, by matching his/her brain surface with a template brain surface. A desired

Itti, Laurent

366

Item memory, source memory, and the medial temporal lobe: Concordant findings from fMRI  

E-Print Network [OSTI]

Item memory, source memory, and the medial temporal lobe: Concordant findings from fMRI and memory Lake City, UT 84143 Contributed by Larry R. Squire, April 4, 2006 We studied item and source memory with fMRI in healthy volun- teers and carried out a parallel study in memory-impaired patients

Wagner, Anthony

367

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

368

Dynamic Surface Reconstruction from 4D-MR Images Matthias Fenchel1  

E-Print Network [OSTI]

Dynamic Surface Reconstruction from 4D-MR Images Matthias Fenchel1 , Stefan Gumhold2 , Hans approach is applied to 4D-MR images of a human heart in motion. 1 Introduction Image segmentation-Peter Seidel3 1 Siemens AG Medical Solutions, Magnetic Resonance, Karl-Schall-Str. 4, 91052 Erlangen 2 TU

Gumhold, Stefan

369

Ontology-Based Annotation of Brain MRI Images Ammar Mechouche1  

E-Print Network [OSTI]

. The system involves both numerical knowledge from an atlas and symbolic knowledge represented in a rule hypotheses for the labels of patches, relying on a numeric atlas, and next selecting some valid combinations comprehension of the paper: · A segment (figure 1) is a part of an external trace of a sulcus. The segments

Paris-Sud XI, Université de

370

Development, testing, and application of quantitative oxygenation imaging from magnetic susceptibility by MRI  

E-Print Network [OSTI]

The healthy brain consumes 20% of total oxygen used by the body under normal conditions. Continuous oxygen delivery to neural tissue is needed to maintain normal brain function and viability. Reliable measurements of brain ...

Fan, Audrey Peiwen

2014-01-01T23:59:59.000Z

371

Data Image  

Science Journals Connector (OSTI)

Data image refers to the sum of all information 74/100,000 available in all datasets linked to a specific name; to all those who have access to databases that name is actually the data image of the real person...

2008-01-01T23:59:59.000Z

372

Resonance Ionization Laser Ion Sources  

E-Print Network [OSTI]

The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

Marsh, B

2013-01-01T23:59:59.000Z

373

Shearing Box Simulations of the MRI in a Collisionless Plasma  

SciTech Connect (OSTI)

We describe local shearing box simulations of turbulence driven by the magnetorotational instability (MRI) in a collisionless plasma. Collisionless effects may be important in radiatively inefficient accretion flows, such as near the black hole in the Galactic Center. The MHD version of ZEUS is modified to evolve an anisotropic pressure tensor. A fluid closure approximation is used to calculate heat conduction along magnetic field lines. The anisotropic pressure tensor provides a qualitatively new mechanism for transporting angular momentum in accretion flows (in addition to the Maxwell and Reynolds stresses). We estimate limits on the pressure anisotropy due to pitch angle scattering by kinetic instabilities. Such instabilities provide an effective ''collision'' rate in a collisionless plasma and lead to more MHD-like dynamics. We find that the MRI leads to efficient growth of the magnetic field in a collisionless plasma, with saturation amplitudes comparable to those in MHD. In the saturated state, the anisotropic stress is comparable to the Maxwell stress, implying that the rate of angular momentum transport may be moderately enhanced in a collisionless plasma.

Sharma, Prateek; Hammett, Gregory, W.; Quataert, Eliot; Stone, James, M.

2005-08-31T23:59:59.000Z

374

Wavelength-tunable optical ring resonators  

DOE Patents [OSTI]

Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

Watts, Michael R. (Albuquerque, NM); Trotter, Douglas C. (Albuquerque, NM); Young, Ralph W. (Albuquerque, NM); Nielson, Gregory N. (Albuquerque, NM)

2009-11-10T23:59:59.000Z

375

Rotational Doppler effect in magnetic resonance  

Science Journals Connector (OSTI)

We compute the shift in the frequency of the spin resonance in a solid that rotates in the field of a circularly polarized electromagnetic wave. Electron-spin resonance, nuclear magnetic resonance, and ferromagnetic resonance are considered. We show that contrary to the case of the rotating LC circuit, the shift in the frequency of the spin resonance has strong dependence on the symmetry of the receiver. The shift due to rotation occurs only when rotational symmetry is broken by the anisotropy of the gyromagnetic tensor, by the shape of the body or by magnetocrystalline anisotropy. General expressions for the resonance frequency and power absorption are derived and implications for experiment are discussed.

S. Lendínez; E. M. Chudnovsky; J. Tejada

2010-11-12T23:59:59.000Z

376

Wavelength-tunable optical ring resonators  

DOE Patents [OSTI]

Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

Watts, Michael R. (Albuquerque, NM); Trotter, Douglas C. (Albuquerque, NM); Young, Ralph W. (Albuquerque, NM); Nielson, Gregory N. (Albuquerque, NM)

2011-07-19T23:59:59.000Z

377

Argonne CNM News: Surface Plasmon Resonance in Interfaced Heterodimers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

378

Functional MR imaging of the awake monkey in a novel vertical large-bore 7 Tesla setup J. Pfeuffer1  

E-Print Network [OSTI]

Functional MR imaging of the awake monkey in a novel vertical large-bore 7 Tesla setup J. Pfeuffer1 , J. Pauls1 , M. Augath1 , T. Steudel1 , H. Merkle2 , N. K. Logothetis1 1 Max Planck InstituteMRI results in the awake trained monkey (Macaca mulatta) using a novel vertical 7T/60cm MR system are reported

Jegelka, Stefanie

379

SciTech Connect: Graphene resonators : analysis and film transfer...  

Office of Scientific and Technical Information (OSTI)

Technical Report: Graphene resonators : analysis and film transfer. Citation Details In-Document Search Title: Graphene resonators : analysis and film transfer. Graphene resonators...

380

Improved measurement of brain deformation during mild head acceleration using a novel tagged MRI sequence  

Science Journals Connector (OSTI)

Abstract In vivo measurements of human brain deformation during mild acceleration are needed to help validate computational models of traumatic brain injury and to understand the factors that govern the mechanical response of the brain. Tagged magnetic resonance imaging is a powerful, noninvasive technique to track tissue motion in vivo which has been used to quantify brain deformation in live human subjects. However, these prior studies required from 72 to 144 head rotations to generate deformation data for a single image slice, precluding its use to investigate the entire brain in a single subject. Here, a novel method is introduced that significantly reduces temporal variability in the acquisition and improves the accuracy of displacement estimates. Optimization of the acquisition parameters in a gelatin phantom and three human subjects leads to a reduction in the number of rotations from 72 to 144 to as few as 8 for a single image slice. The ability to estimate accurate, well-resolved, fields of displacement and strain in far fewer repetitions will enable comprehensive studies of acceleration-induced deformation throughout the human brain in vivo.

Andrew K. Knutsen; Elizabeth Magrath; Julie E. McEntee; Fangxu Xing; Jerry L. Prince; Philip V. Bayly; John A. Butman; Dzung L. Pham

2014-01-01T23:59:59.000Z

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

Prototype explosives-detection system based on nuclear-resonance absorption in nitrogen  

SciTech Connect (OSTI)

A prototype explosives-detection system (EDS) that was developed for experimental evaluation of a nuclear-resonance absorption technique is described. The major subsystems are a proton accelerator and beam transport, high-temperature proton target, an airline-luggage tomographic inspection station, and an image-processing/detection-alarm subsystem. The detection system performance, based on a limited experimental test, is reported.

Morgado, R.E.; Arnone, G.; Cappiello, C.C.; Gardner, S.D.; Hollas, C.L.; Ussery, L.E.; White, J.M.; Zahrt, J.D. [Los Alamos National Lab., NM (United States); Krauss, R.A. [Federal Aviation Administration, Atlantic City International Airport, NJ (United States)

1994-06-01T23:59:59.000Z

382

On the Dynamics of Magnetic Fluids in Magnetic Resonance Padraig J. Cantillon-Murphy  

E-Print Network [OSTI]

On the Dynamics of Magnetic Fluids in Magnetic Resonance Imaging by Padraig J. Cantillon-Murphy Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of Electric'algngineering and Computer Science May 22nd, 2008. Certified

383

Stochastic resonance for quantum channels  

Science Journals Connector (OSTI)

The concept of stochastic resonance in nonlinear dynamics is applied to interpret the capacity of noisy quantum channels. The two-Pauli channel is used to illustrate the idea. The fidelity of the channel is also considered. Noise enhancement is found for the channel fidelity but not for the channel capacity.

Julian Juhi-Lian Ting

1999-03-01T23:59:59.000Z

384

Resonating Platforms for Nanomaterial Analysis  

E-Print Network [OSTI]

. · Nanoparticles are also being developed for water remediation. In these applications, changes in surface. · The development of innovative resonant NEMS devices with high quality factors (Qs) in liquid offers the potential are being used to determine the feasibility of nanoparticle use in water remediation. 853-08-06a #12

Perkins, Richard A.

385

Nonlinear resonance in vibrating strings  

Science Journals Connector (OSTI)

A simple stretched string driven sinusoidally is commonly used to illustrate the concepts of resonance and eigenmodes. In practice such a system rarely executes planar oscillation but prefers circular motion. This is shown to be a consequence of the intrinsic nonlinearity of the stretched string oscillator and the associated parametric coupling between the two transverse polarizations.

John A. Elliott

1982-01-01T23:59:59.000Z

386

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

387

Piezoelectric MEMS resonator characterization and filter design  

E-Print Network [OSTI]

This thesis presents modeling and first measurements of a new piezoelectric MEMS resonator developed at Draper Laboratory. In addition, some simple filter designs incorporating the resonator with predicted performance ...

Kang, Joung-Mo, 1978-

2004-01-01T23:59:59.000Z

388

Second Harmonic Resonance for Equatorial Waves  

Science Journals Connector (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

389

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...

Jeter, Edward Hilton

2013-02-22T23:59:59.000Z

390

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

391

Houchun Harry Hu, Ph.D. Birthdate: April 24, 1979  

E-Print Network [OSTI]

Cum Laude ACADEMIC POSITIONS and RESEARCH EXPERIENCE 07/2011 ­ present, Assistant Professor Radiology Resonance Imaging Distinguished Reviewer 2009 ­ Present, Radiology, Magnetic Resonance Imaging (MRI), IEEE of Obesity, Obesity, International Journal of Pediatric Obesity, Magnetic Resonance Materials in Physics

Southern California, University of

392

Reducing the Probability of Capture into Resonance  

E-Print Network [OSTI]

A migrating planet can capture planetesimals into mean motion resonances. However, resonant trapping can be prevented when the drift or migration rate is sufficiently high. Using a simple Hamiltonian system for first and second order resonances, we explore how the capture probability depends on the order of the resonance, drift rate and initial particle eccentricity. We present scaling factors as a function of the planet mass and resonance strength to estimate the planetary migration rate above which the capture probability drops to less than 1/2. Applying our framework to multiple extra solar planetary systems that have two planets locked in resonance, we estimate lower limits for the outer planet's migration rate allowing resonance capture of the inner planet. Mean motion resonances are comprised of multiple resonant subterms. We find that the corotation subterm can reduce the probability of capture when the planet eccentricity is above a critical value. We present factors that can be used to estimate this critical planet eccentricity. Applying our framework to the migration of Neptune, we find that Neptune's eccentricity is near the critical value that would make its 2:1 resonance fail to capture twotinos. The capture probability is affected by the separation between resonant subterms and so is also a function of the precession rates of the longitudes of periapse of both planet and particle near resonance.

Alice C. Quillen

2005-11-03T23:59:59.000Z

393

Resonant phenomena in slowly perturbed elliptic billiards  

E-Print Network [OSTI]

We consider an elliptic billiard whose shape slowly changes. During slow evolution of the billiard certain resonance conditions can be fulfilled. We study the phenomena of capture into a resonance and scattering on resonances which lead to the destruction of the adiabatic invariance in the system.

A. P. Itin; A. I. Neishtadt

2005-12-11T23:59:59.000Z

394

Electrically driven spin resonance in silicon carbide color centers  

E-Print Network [OSTI]

We demonstrate that the spin of optically addressable point defects can be coherently driven with AC electric fields. Based on magnetic-dipole forbidden spin transitions, this scheme enables spatially confined spin control, the imaging of high-frequency electric fields, and the characterization of defect spin multiplicity. While we control defects in SiC, these methods apply to spin systems in many semiconductors, including the nitrogen-vacancy center in diamond. Electrically driven spin resonance offers a viable route towards scalable quantum control of electron spins in a dense array.

P. V. Klimov; A. L. Falk; B. B. Buckley; D. D. Awschalom

2013-10-17T23:59:59.000Z

395

Conductivity of graphene with resonant and non resonant adsorbates Guy Trambly de Laissardi`ere1  

E-Print Network [OSTI]

Conductivity of graphene with resonant and non resonant adsorbates Guy Trambly de Laissardi`ere1 in graphene with adsorbates that fully takes into account localization effects and loss of electronic of the adsorbates and analyze in detail cases with resonant or non resonant scattering. For both models we identify

Paris-Sud XI, Université de

396

Proton Resonance Spectroscopy -- Final Report  

SciTech Connect (OSTI)

This report summarizes work supported by the DOE Grant DE-FG02-96ER40990 during its duration from June 1996 to May 2009. Topics studied include (1) statistical descriptions of nuclear levels and measurements of proton resonances relevant to such descriptions, including measurements toward a complete level scheme for 30P, (2) the development of methods to estimate the missing fraction of levels in a given measurement, and (3) measurements at HRIBF relevant to nuclear astrophysics.

Shriner, Jr, J F

2009-07-27T23:59:59.000Z

397

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

398

History Images  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

399

On properties of Velikhov-Chandrasekhar MRI in ideal and non-ideal plasma  

E-Print Network [OSTI]

Conditions of Velikhov-Chandrasekhar magneto-rotational instability in ideal and non-ideal plasmas are examined. Linear WKB analysis of hydromagnetic axially symmetric flows shows that in the Rayleigh-unstable hydrodynamic case where the angular momentum decreases with radius, the MRI branch becomes stable, and the magnetic field suppresses the Rayleigh instability at small wavelengths. We investigate the limiting transition from hydromagnetic flows to hydrodynamic flows. The Rayleigh mode smoothly transits to the hydrodynamic case, while the Velikhov-Chandrasekhar MRI mode completely disappears without the magnetic field. The effects of viscosity and magnetic diffusivity in plasma on the MRI conditions in thin accretion discs are studied. We find the limits on the mean free-path of ions allowing MRI to operate in such discs.

Shakura, N I

2014-01-01T23:59:59.000Z

400

E-Print Network 3.0 - acute pancreatitis mri Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Gadolinium Summary: -resolution MRI with a 3-dimensional LGE sequence before ablation, IPA, and 3moPA using a 3-T scanner. The acute... of 37 100%) who underwent RFA for AF,...

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

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

402

Resonant detection of axion mediated forces with Nuclear Magnetic Resonance  

E-Print Network [OSTI]

We describe a method based on precision magnetometry that can extend the search for axion-mediated spin-dependent forces by several orders of magnitude. By combining techniques used in nuclear magnetic resonance and short-distance tests of gravity, our approach can substantially improve upon current experimental limits set by astrophysics, and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. Our method is sensitive to PQ axion decay constants between 10^9 and 10^12 GeV or axion masses between 10^-6 and 10^-3 eV, independent of the cosmic axion abundance.

Asimina Arvanitaki; Andrew A. Geraci

2014-03-05T23:59:59.000Z

403

Cyclotron Resonance in Bilayer Graphene  

Science Journals Connector (OSTI)

We present the first measurements of cyclotron resonance of electrons and holes in bilayer graphene. In magnetic fields up to B=18??T, we observe four distinct intraband transitions in both the conduction and valence bands. The transition energies are roughly linear in B between the lowest Landau levels, whereas they follow B for the higher transitions. This highly unusual behavior represents a change from a parabolic to a linear energy dispersion. The density of states derived from our data generally agrees with the existing lowest order tight binding calculation for bilayer graphene. However, in comparing data to theory, a single set of fitting parameters fails to describe the experimental results.

E. A. Henriksen; Z. Jiang; L.-C. Tung; M. E. Schwartz; M. Takita; Y.-J. Wang; P. Kim; H. L. Stormer

2008-02-27T23:59:59.000Z

404

Resonance Broadening of Spectral Lines  

Science Journals Connector (OSTI)

A formalism introduced previously by the author is used to calculate the shape of an absorption line in a gas, taking account of the "resonance" interaction between like atoms. The most serious approximation is the neglect of the effect of translational motion. An asymmetric line is obtained, with the maximum shifted slightly toward the red. Some simple classical considerations also agree qualitatively with the results. Various properties of the line shape obtained are briefly discussed. The neglect of translational motion makes it impossible to compare the results with experiments performed up to the present time.

C. Alden Mead

1960-11-01T23:59:59.000Z

405

Sphericity determination using resonant ultrasound spectroscopy  

DOE Patents [OSTI]

A method is provided for grading production quantities of spherical objects, such as roller balls for bearings. A resonant ultrasound spectrum (RUS) is generated for each spherical object and a set of degenerate sphere-resonance frequencies is identified. From the degenerate sphere-resonance frequencies and known relationships between degenerate sphere-resonance frequencies and Poisson's ratio, a Poisson's ratio can be determined, along with a 'best' spherical diameter, to form spherical parameters for the sphere. From the RUS, fine-structure resonant frequency spectra are identified for each degenerate sphere-resonance frequency previously selected. From each fine-structure spectrum and associated sphere parameter values an asphericity value is determined. The asphericity value can then be compared with predetermined values to provide a measure for accepting or rejecting the sphere. 14 figs.

Dixon, R.D.; Migliori, A.; Visscher, W.M.

1994-10-18T23:59:59.000Z

406

Nuclear medicine and imaging research (quantitative studies in radiopharmaceutical science)  

SciTech Connect (OSTI)

This report describes three studies aimed at using radiolabeled pharmaceuticals to explore brain function and anatomy. The first section describes the chemical preparation of (F18)fluorinated benzamides (dopamine D-2 receptor tracers), (F18)fluorinated benzazepines (dopamine D-1 receptor tracers), and tissue distribution of (F18)-fluoxetine (serotonin reuptake site tracer). The second section relates pharmacological and behavioral studies of amphetamines. The third section reports on progress made with processing of brain images from CT, MRI and PET/SPECT with regards to brain metabolism of glucose during mental tasks.

Cooper, M.; Beck, R.N.

1992-06-01T23:59:59.000Z

407

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

408

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

409

SU?GG?J?138: Effect of RF Pulse Dwell Time on Eddy Current and Motion Compensation in Multi?Shot Diffusion?Weighted MRI  

Science Journals Connector (OSTI)

Purpose: Diffusion?weighted (DW) MRI can provide information to improve target delineation in radiation treatment planning. The widely used twice?refocused spin?echo (TRSE) sequence is optimized to diminish eddy current?induced geometric distortions. However the TRSE sequence imposes a longer minimum echo time which precludes its use in acquiring DW images in tissues with short T2s. We found that radiofrequency (RF) pulse dwell times can also affect DW image quality and demonstrate that high?fidelity multi?shot DW images can be obtained using the non?optimized Stejkal and Tanner (ST) sequence when short RF pulse dwell times are employed. Method and Materials: A pulse sequence of our own design was implemented to acquire DW images using ST and TRSE diffusion?encoding schemes with 25 usec and 2 usec RF pulse dwell times. Single? and multi?shot spiral DW images (b=0 1000 s/mm2) of phantom and healthy volunteer were acquired on a 3.0T Siemens Verio scanner.Images were reconstructed offline using custom software developed at our Institution. Results: Single? and multi?shot non?DW images did not exhibit a dependence on RF pulse dwell time. Furthermore single?shot DW images acquired with the TRSE method did not exhibit a dependence on RF pulse dwell time. However multi?shot DW images exhibited significant artifacts at long RF pulse dwell times even for the optimized TRSE method. Reducing the RF pulse dwell time improved the inherent immunity of the sequences to eddy current and motion?induced artifacts permitting acquisition of high?fidelity multi?shot DW images even with the non?optimized ST method. Conclusions: Compensation of eddy current and motion?induced artifacts in multi?shot DW imaging can be affected by choice of RF pulse dwell time. High?fidelity multi?shot DW images of short T2 tissues can be obtained using the non?optimized traditional ST method so long as the RF pulse dwell time is kept short. Research supported by Siemens Healthcare

E Paulson; E Ahunbay; X Li

2010-01-01T23:59:59.000Z

410

Lensless Imaging of Magnetic Nanostructures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

411

Combining Feedback Absorption Spectroscopy, Amplified Resonance...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling Cummins...

412

Scalar-Pseudoscalar scattering and pseudoscalar resonances  

SciTech Connect (OSTI)

The interactions between the f{sub 0}(980) and a{sub 0}(980) scalar resonances and the lightest pseudoscalar mesons are studied. We first obtain the interacting kernels, without including any ad hoc free parameter, because the lightest scalar resonances are dynamically generated. These kernels are unitarized, giving the final amplitudes, which generate pseudoscalar resonances, associated with the K(1460), {pi}(1300), {pi}(1800), {eta}(1475) and X(1835). We also consider the exotic channels with I = 3/2 and I{sup G} = 1{sup +} quantum numbers. The former could be also resonant in agreement with a previous prediction.

Albaladejo, M.; Oller, J. A.; Roca, L. [Departamento de Fisica, Univerisidad de Murcia, E-30071, Murcia (Spain)

2011-05-23T23:59:59.000Z

413

Resonant seismic emission of subsurface objects  

E-Print Network [OSTI]

E . , and S. Keydar, 1998, Seismic monitoring of diffractionthe barrel. The Resonant Seismic Emission Source ReceiverFigure 1. Geometry o f the seismic experiment to locate a

Korneev, Valeri A.

2010-01-01T23:59:59.000Z

414

Coherence of magnetic resonators in a metamaterial  

SciTech Connect (OSTI)

The coherence of periodic magnetic resonators (MRs) under oblique incidence is studied using simulations. The correlated phase of interaction including both the retardation effect and relative phase difference between two MRs is defined, and it plays a key role in the MR interaction. The correlated phase is anisotropic, as is the coherence condition. The coherence condition is the same as the Wood's anomaly and verified by the Fano resonance. This study shows that the applications of the Fano resonance of periodic MRs will become widespread owing to achieving the Fano resonance simply by tuning the incident angle.

Hou, Yumin, E-mail: ymhou@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

2013-12-15T23:59:59.000Z

415

Metal nano-strip optical resonators  

Science Journals Connector (OSTI)

Rectangular gold and silver nano-strips embedded in glass or water are considered as optical resonators. Their scattering cross section and field enhancements in the case of...

Søndergaard, Thomas; Bozhevolnyi, Sergey I

2007-01-01T23:59:59.000Z

416

Evaluation of Cerebral Energy Demand during Graded Hypercapnia and Validation of Optical Blood Flow Measurements against ASL fMRI  

Science Journals Connector (OSTI)

We validate optical cerebral blood flow measurements against functional MRI in a rat model during graded hypercapnia. We test the iso-metabolic assumption and demonstrate an apaprent...

Carp, Stefan; Franceschini, Maria A; Boas, David A; Kim, Young R

417

Coherence Effects in Resonance Fluorescence  

Science Journals Connector (OSTI)

The crossed-level method of atomic spectroscopy is discussed and the angular distribution formula for both the incoherent and coherent resonance scattering is derived. The form of this distribution function, as given here, explicity displays the geometric factors depending on radiation propagation vectors. With the application to hydrogen in mind, the distribution function is expressed explicitly for single electron transitions with external fields possessing axial symmetry. The properties of the distribution function are discussed with emphasis on the case of unpolarized radiation. For the case of hydrogen there are two possible applications of major interest. The first concerns the possibility of a precision measurement of the 2p fine structure splitting and, hence, a determination of the fine structure constant. Explicit results for the shape and other properties of the resonance line with a uniform magnetic field obtained. The other application is concerned with the possibility of measuring the 2s-2p Lamb splitting. This requires an electric field parallel to the magnetic field. Unfortunately, the level crossings which are sensitive to the Lamb splitting cannot radiate sufficiently rapidly while those which do radiate appreciably occur at field strengths which are extremely insensitive to the Lamb splitting.

M. E. Rose and R. L. Carovillano

1961-05-15T23:59:59.000Z

418

Single-Molecule Stochastic Resonance  

Science Journals Connector (OSTI)

Stochastic resonance (SR) is a well-known phenomenon in dynamical systems. It consists of the amplification and optimization of the response of a system assisted by stochastic (random or probabilistic) noise. Here we carry out the first experimental study of SR in single DNA hairpins which exhibit cooperatively transitions from folded to unfolded configurations under the action of an oscillating mechanical force applied with optical tweezers. By varying the frequency of the force oscillation, we investigate the folding and unfolding kinetics of DNA hairpins in a periodically driven bistable free-energy potential. We measure several SR quantifiers under varied conditions of the experimental setup such as trap stiffness and length of the molecular handles used for single-molecule manipulation. We find that a good quantifier of the SR is the signal-to-noise ratio (SNR) of the spectral density of measured fluctuations in molecular extension of the DNA hairpins. The frequency dependence of the SNR exhibits a peak at a frequency value given by the resonance-matching condition. Finally, we carry out experiments on short hairpins that show how SR might be useful for enhancing the detection of conformational molecular transitions of low SNR.

K. Hayashi; S. de Lorenzo; M. Manosas; J. M. Huguet; F. Ritort

2012-08-24T23:59:59.000Z

419

A Comparison of Magnetic Resonance, X-ray and Positron Emission Particle Tracking Measurements of a Single Jet of Gas Entering a Bed of Particles  

E-Print Network [OSTI]

resolution ~1.5 ms ~0.2 ms ~1 ms spatial resolution ~1 mm ~0.1 mm ~0.5 mm velocity yes no yes dispersion yes no yes granular temperature yes no yes scale (bed dia.) 50 mm 270 mm 750 mm 3 Image Analysis 3.1 MRI MR images were processed using... .R., McNeil, P. (1993) Positron emission particle tracking - a technique for studying flow within engineering equipment. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 326...

Pore, M.; Ong, G. H.; Boyce, C. M.; Materazzi, M.; Gargiuli, J.; Leadbeater, T.; Sederman, A. J.; Dennis, J. S.; Holland, D. J.; Ingram, A.; Lettieri, P.; Parker, D. J.

2014-01-01T23:59:59.000Z

420

Artificial neural network prediction of ischemic tissue fate in acute stroke imaging  

E-Print Network [OSTI]

Artificial neural network prediction of ischemic tissue fate in acute stroke imaging Shiliang Huang Multimodal magnetic resonance imaging of acute stroke provides predictive value that can be used to guide stroke therapy. A flexible artificial neural network (ANN) algorithm was developed and applied to predict

Duong, Timothy Q.

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

Cerebral lateralization of face-sensitive areas in left-handers: Only the FFA does not get it right  

E-Print Network [OSTI]

magnetic resonance imaging (fMRI) (faces, cars, and their phase-scrambled versions). All face field defects; He´caen and Angelergues, 1962; Meadows, 1974). The view that right unilat- eral lesions

Rossion, Bruno

422

A diffusion-free and linear-energy-transfer-independent nanocomposite Fricke gel dosimeter  

E-Print Network [OSTI]

, Wako, Saitama 351-0198, Japan c Department of Nuclear Engineering and Management, Graduate School resonance imaging (MRI). This has pioneered modern gel dosimetry (Baldock et al., 2010; Schreiner, 2004

Ishikawa, Kenichi L.

423

ORIGINAL CONTRIBUTION Diffusion Tensor Tractography  

E-Print Network [OSTI]

with dichotomized long-term outcome in pediatric patients with TBI.11 A novel magnetic resonance imaging (MRI, Richardson (Ms Wang and Drs Bakhadirov and Abdi); and Departments of Radiology (Drs Devous, McColl, W

O'Toole, Alice J.

424

Nanometric Optical Imaging Frontiers in Chemical Imaging  

E-Print Network [OSTI]

Nanometric Optical Imaging Frontiers in Chemical Imaging Seminar Series Presented by... Professor growing field which has provided for nanometric optical imaging in the near-field. Even though a variety of techniques are being developed with nanometric optical imaging potential, near-field optics remains the most

425

Lensless Imaging of Magnetic Nanostructures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

426

Lensless Imaging of Magnetic Nanostructures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

427

Lensless Imaging of Magnetic Nanostructures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

428

Lensless Imaging of Magnetic Nanostructures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

429

TU?D?352?08: Innovative Instrumentation for Resonant Cancer Theranostics  

Science Journals Connector (OSTI)

Purpose: Most current diagnostic and therapeutic X?ray techniques use nonspecific broadband continuum radiation. By taking advantage of resonant absorption complexes in heavy?element?tagged nanoparticles or contrast agents delivered to disease sites we can use tunable narrow energy bands for both therapy and diagnosis (theranostics) that is extremely efficient and minimizes radiation exposure to neighboring tissue. Method and Materials: We use an electron beamion trap (EBIT) as the source of tunable monochromatic X?rays for imaging and therapy and a cryogenic x?ray microcalorimeter to form spectroscopically resolved images. The high resolving power (E/?E > 2000) and low background of the microcalorimeter are essential for verifying the resonant absorption signatures predicted by our relativistic R?matrix calculations. The microcalorimeter is used to tune the X?ray emission from the EBIT plasma to the band of resonant absorption lines in the tagged nanoparticles. The unprecedented signal to noise of the microcalorimeter means that it can identify line emission with less than 20 counts per energy resolution element making the eventual dose necessary for diagnosticimaging potentially very low. Results: We describe the EBIT and the microcalorimeter with emphasis on the X?ray energy range required by cancer theranostics. Preliminary studies with the microcalorimeter demonstrate that it can image atomic fingerprints of heavy?element uptake such as goldnanoparticles that can be embedded in malignant tissue. Conclusion: We discuss two key component technologies for atomic level theranostics : The electron beamion trap is a smart x?ray source capable of generating monoenergetic resonant X?rays that maximally interact with the matching high?Z contrast agent or nanoparticles; the spectroscopic microcalorimeter is a “zero?background” detector by design and can discriminate resonant signatures with 10 times better resolution than any other X?ray spectrometer thus providing very high sensitivity for detailed mapping of elemental distributions such as goldnanoparticles and platinum?based chemotherapeutic compounds.

E Silver; A Pradhan; Y Yu

2008-01-01T23:59:59.000Z

430

Giant Quadrupole-Resonance in Ni Isotopes  

E-Print Network [OSTI]

Inelastic scattering of 129 MeV alpha particles has been used to excite the giant quadrupole resonance in Ni-58, Ni-60, Ni-62, Ni-64. The resonance was found to exhaust 58 +/- 12%, 76 +/- 14%, 78 +/- 14%, and 90 +/-16% of the E2 energy-weighted sum...

Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

1992-01-01T23:59:59.000Z

431

Quantum logic gates for superconducting resonator qudits  

SciTech Connect (OSTI)

We study quantum information processing using superpositions of Fock states in superconducting resonators as quantum d-level systems (qudits). A universal set of single and coupled logic gates is theoretically proposed for resonators coupled by superconducting circuits of Josephson junctions. These gates use experimentally demonstrated interactions and provide an attractive route to quantum information processing using harmonic oscillator modes.

Strauch, Frederick W. [Williams College, Williamstown, Massachusetts 01267 (United States)

2011-11-15T23:59:59.000Z

432

Contact replacement for NMR resonance assignment  

Science Journals Connector (OSTI)

......experimental and synthetic datasets, it is robust to...edu 1 INTRODUCTION Nuclear magnetic resonance...experimental and synthetic datasets, it is robust to...edu 1 INTRODUCTION Nuclear magnetic resonance...an ensemble for a dataset, while bars indicate...replacement and nuclear vector replacement......

Fei Xiong; Gopal Pandurangan; Chris Bailey-Kellogg

2008-07-01T23:59:59.000Z

433

Sequential resonant tunneling in quantum cascade lasers  

SciTech Connect (OSTI)

A model of sequential resonant tunneling transport among two-dimensional subbands that takes into account explicitly elastic scattering is investigated. It is compared to transport measurements performed on quantum cascade lasers, where resonant tunneling processes are known to be dominating. Excellent agreement is found between experiment and theory over a large range of current, temperature, and device structures.

Terazzi, Romain; Gresch, Tobias; Wittmann, Andreas; Faist, Jerome [Quantum Optoelectronics Group, Institute for Quantum Electronics, ETH, 8086 Zuerich (Switzerland)

2008-10-15T23:59:59.000Z

434

Coherence of resonant tunneling in heterostructures  

Science Journals Connector (OSTI)

A simple argument is put forward to substantiate the rule that either coherent resonant tunneling or sequential tunneling will occur according to whether the natural energy width for the former (in frequency units) is large compared to or small compared to the scattering frequency for an electron in the quantum-well two-dimensional subband based on the resonant quasilevel.

Peter J. Price

1987-07-15T23:59:59.000Z

435

Doppler Effect of Nuclear Resonance Level  

Science Journals Connector (OSTI)

... cent. It has been pointed out by Frisch5 that these widths are comparable with the Doppler width which such resonance must show in consequence of the thermal agitation of the capturing ... of the thermal agitation of the capturing nuclei. According to Bethe and Placzek3, the Doppler width is Er being the resonance energy and M the mass of the nucleus. ...

HANS VON HALBAN; HUGH PAXTON

1938-01-15T23:59:59.000Z

436

Resonances and the thermonuclear reaction rate  

E-Print Network [OSTI]

We present an approximate analytic expression for thermonuclear reaction rate of charged particles when the cross section contains a single narrow or wide resonance described by a Breit-Wigner shape. The resulting expression is uniformly valid as the effective energy and resonance energy coalesce. We use our expressions to calculate the reaction rate for $^{12}$C(p,$\\gamma$)$^{13}$N.

M. S. Hussein; M. Ueda; A. J. Sargeant; M. P. Pato

2003-07-21T23:59:59.000Z

437

High-field fMRI unveils orientation columns in humans  

Science Journals Connector (OSTI)

...Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School...subjects used a bite bar that matched the dental impressions of the subject by using hydroplastic...Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School...

Essa Yacoub; Noam Harel; Kâmil U?urbil

2008-01-01T23:59:59.000Z

438

Original Contributions MRI diffusion tensor reconstruction with PROPELLER data acquisition  

E-Print Network [OSTI]

Lake City, UT 84108, USA c Division of Nuclear Medicine, AZ-VUB University Hospital, Vrije Universiteit Brussel, Brussels, Belgium d Department of Nuclear Medicine and Functional Imaging, E. O. Lawrence be obtained to form an adequate dataset for reconstruction of the full tensor field or, at least, of its

Utah, University of

439

Development of techniques in magnetic resonance and structural studies of the prion protein  

SciTech Connect (OSTI)

Magnetic resonance is the most powerful analytical tool used by chemists today. Its applications range from determining structures of large biomolecules to imaging of human brains. Nevertheless, magnetic resonance remains a relatively young field, in which many techniques are currently being developed that have broad applications. In this dissertation, two new techniques are presented, one that enables the determination of torsion angles in solid-state peptides and proteins, and another that involves imaging of heterogenous materials at ultra-low magnetic fields. In addition, structural studies of the prion protein via solid-state NMR are described. More specifically, work is presented in which the dependence of chemical shifts on local molecular structure is used to predict chemical shift tensors in solid-state peptides with theoretical ab initio surfaces. These predictions are then used to determine the backbone dihedral angles in peptides. This method utilizes the theoretical chemicalshift tensors and experimentally determined chemical-shift anisotropies (CSAs) to predict the backbone and side chain torsion angles in alanine, leucine, and valine residues. Additionally, structural studies of prion protein fragments are described in which conformationally-dependent chemical-shift measurements were made to gain insight into the structural differences between the various conformational states of the prion protein. These studies are of biological and pathological interest since conformational changes in the prion protein are believed to cause prion diseases. Finally, an ultra-low field magnetic resonance imaging technique is described that enables imaging and characterization of heterogeneous and porous media. The notion of imaging gases at ultra-low fields would appear to be very difficult due to the prohibitively low polarization and spin densities as well as the low sensitivities of conventional Faraday coil detectors. However, Chapter 5 describes how gas imaging at ultra-low fields is realized by incorporating the high sensitivities of a dc superconducting quantum interference device (SQUID) with the high polarizations attainable through optica11y pumping {sup 129}Xe gas.

Bitter, Hans-Marcus L.

2000-07-01T23:59:59.000Z

440

On a plasmon resonance in ellipsoidal nanoparticles  

SciTech Connect (OSTI)

The dependence of the plasmon resonance frequency of metal ellipsoids of revolution on their eccentricity is calculated. The plasmon resonance shifts to the red with increasing eccentricity and its intensity increases. The resonance intensity increases with decreasing the imaginary part of the dielectric constant of a metal. The plasmon resonance frequency in a suspension of randomly oriented prolate nanoparticles (with a large eccentricity) almost exactly coincides with that in a suspension of oriented particles. These features permit the efficient improvement of the sensitivity and resolving power of optoacoustic tomography by introducing prolate metal nanoparticles into the region of an object under study. The possibility of plasmon resonance narrowing by introducing metal nanoparticles into an amplifying medium is pointed out. (laser applications and other topics in quantum electronics)

Oraevsky, A A [University of Texas, Medical Branch, Galveston, Texas (United States); Oraevsky, Anatolii N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2002-01-31T23:59:59.000Z

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

Hybrid simulation of electron cyclotron resonance heating  

Science Journals Connector (OSTI)

Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

T. Ropponen; O. Tarvainen; P. Suominen; T.K. Koponen; T. Kalvas; H. Koivisto

2008-01-01T23:59:59.000Z

442

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

Science Journals Connector (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

443

A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization  

SciTech Connect (OSTI)

The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate magnetic resonance (MR) techniques and acoustic measurements to improve predictability of the pay zone in two hydrocarbon reservoirs. This was accomplished by extracting the fluid property parameters using MR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurements were compared with petrographic analysis results to determine the relative roles of petrographic elements such as porosity type, mineralogy, texture, and distribution of clay and cement in creating permeability heterogeneity.

Parra, J.O.

2001-01-26T23:59:59.000Z

444

Atlas-based attenuation correction for small animal PET/MRI scanners Abhijit J. Chaudhari, ajchaudhari@ucdavis.edu,  

E-Print Network [OSTI]

Atlas-based attenuation correction for small animal PET/MRI scanners 1 Abhijit J. Chaudhari densities and not on electron densities. We propose a deformable mouse atlas-based registration method for AC in small animal PET/MRI. In this method, we first match the posture of the atlas to the posture

Leahy, Richard M.

445

Origins of Spatial Working Memory Deficits in Schizophrenia: An Event-Related fMRI and Near-Infrared  

E-Print Network [OSTI]

Origins of Spatial Working Memory Deficits in Schizophrenia: An Event-Related fMRI and Near-Infrared performance with the near-infrared spectroscopy (NIRS) using the same spatial WM task. Distinct types S (2008) Origins of Spatial Working Memory Deficits in Schizophrenia: An Event-Related fMRI and Near-Infrared

Park, Sohee

446

C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Abstract: Secondary...

447

Nuclear magnetic resonance in a thallium single crystal.  

E-Print Network [OSTI]

??Nuclear magnetic resonance studies in single crystals of thallium have been performed for the first time. The resonance frequency, line width and second moment were… (more)

Schratter, Jacob Jack

2012-01-01T23:59:59.000Z

448

SENSITIVE OPTOACOUSTIC DETECTION OF CARBON MONOXIDE BY RESONANCE ABSORPTION  

E-Print Network [OSTI]

Monoxide by Resonance Absorption Robert Gerlach and Nabil M.MONOXIDE BY RESONANCE ABSORPTION Robert Gerlach and Nabil M.the context of atmospheric absorption. The carbon monoxide

Gerlach, R.

2011-01-01T23:59:59.000Z

449

Neutron Spin Resonance in Iron-based Superconductors | The Ames...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Neutron Spin Resonance in Iron-based Superconductors The propagation of a novel magnetic excitation in the superconducting state, called a spin resonance, has been observed in iron...

450

NDE 701: Enhanced Resonance Inspection for Light Metal Castings...  

Broader source: Energy.gov (indexed) [DOE]

NDE 701: Enhanced Resonance Inspection for Light Metal Castings NDE 701: Enhanced Resonance Inspection for Light Metal Castings Presentation from the U.S. DOE Office of Vehicle...

451

MagLab Audio Dictionary: Fourier Transform Ion Cyclotron Resonance...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fourier Transform Ion Cyclotron Resonance (FT-ICR)? Now Playing: What's Fourier Transform Ion Cyclotron Resonance (FT-ICR)? Enable Javascript and Flash to stream the Magnet Minute...

452

MagLab Audio Dictionary: Nuclear Magnetic Resonance (NMR)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Nuclear Magnetic Resonance (NMR)? Now Playing: What's Nuclear Magnetic Resonance (NMR)? Enable Javascript and Flash to stream the Magnet Minute Tim Cross Associated Links The NMR...

453

MagLab Audio Dictionary: Electron Magnetic Resonance (EMR)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron Magnetic Resonance (EMR)? Now Playing: What's Electron Magnetic Resonance (EMR)? Enable Javascript and Flash to stream the Magnet Minute Stephen Hill Associated Links The...

454

Synergistic enhancement of iron oxide nanoparticle and gadolinium for dual-contrast MRI  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer MR contrast agents exert influence on T{sub 1} or T{sub 2} relaxation time of the surrounding tissue. Black-Right-Pointing-Pointer Combined use of iron oxide and Gd-DTPA can improve the sensitivity/specificity of lesion detection. Black-Right-Pointing-Pointer Dual contrast MRI enhances the delineation of tumor borders and small lesions. Black-Right-Pointing-Pointer The effect of DC-MRI can come from the high paramagnetic susceptibility of Gd{sup 3+}. Black-Right-Pointing-Pointer The effect of DC-MRI can also come from the distinct pharmacokinetic distribution of SPIO and Gd-DTPA. -- Abstract: Purpose: The use of MR contrast agents allows accurate diagnosis by exerting an influence on the longitudinal (T{sub 1}) or transverse (T{sub 2}) relaxation time of the surrounding tissue. In this study, we combined the use of iron oxide (IO) particles and nonspecific extracellular gadolinium chelate (Gd) in order to further improve the sensitivity and specificity of lesion detection. Procedures: With a 7-Tesla scanner, pre-contrasted, IO-enhanced and dual contrast agent enhanced MRIs were performed in phantom, normal animals, and animal models of lymph node tumor metastases and orthotopic brain tumor. For the dual-contrast (DC) MRI, we focused on the evaluation of T{sub 2} weighted DC MRI with IO administered first, then followed by the injection of a bolus of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). Results: Based on the C/N ratios and MRI relaxometry, the synergistic effect of coordinated administration of Gd-DTPA and IO was observed and confirmed in phantom, normal liver and tumor models. At 30 min after administration of Feridex, Gd-DTPA further decreased T{sub 2} relaxation in liver immediately after the injection. Additional administration of Gd-DTPA also immediately increased the signal contrast between tumor and brain parenchyma and maximized the C/N ratio to -4.12 {+-} 0.71. Dual contrast MRI also enhanced the delineation of tumor borders and small lesions. Conclusions: DC-MRI will be helpful to improve diagnostic accuracy and decrease the threshold size for lesion detection.

Zhang, Fan [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States) [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361005 (China); Huang, Xinglu [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States)] [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Qian, Chunqi [Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892 (United States) [Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892 (United States); Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361005 (China); Zhu, Lei [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States) [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361005 (China); Hida, Naoki [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States)] [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Niu, Gang, E-mail: niug@mail.nih.gov [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States)] [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States); Chen, Xiaoyuan, E-mail: shawn.chen@nih.gov [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States)] [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Bethesda, MD 20892 (United States)

2012-09-07T23:59:59.000Z

455

Subwavelength resonant nanostructured films for sensing  

SciTech Connect (OSTI)

We present a novel subwavelength nanostructure architecture that may be utilized for optical standoff sensing applications. The subwavelength structures are fabricated via a combination of nanoimprint lithography and metal sputtering to create metallic nanostructured films encased within a transparent media. The structures are based on the open ring resonator (ORR) architecture and have their analog in resonant LC circuits, which display a resonance frequency that is inversely proportional to the square root of the product of the inductance and capacitance. Therefore, any perturbation of the nanostructured films due to chemical or environmental effects can alter the inductive or capacitive behavior of the subwavelength features, which can shift the resonant frequency and provide an indication of the external stimulus. This shift in resonance can be interrogated remotely either actively using either laser illumination or passively using hyperspectral or multispectral sensing. These structures may be designed to be either anisotropic or isotropic, which can also provide polarization-sensitive interrogation. Due to the nanometer-scale of the structures, they can be tailored to be optically responsive in the visible or near infrared spectrum with a highly reflective resonant peak that is dependent solely on structural dimensions and material characteristics. We present experimental measurements of the optical response of these structures as a function of wavelength, polarization, and incident angle demonstrating the resonant effect in the near infrared region. Numerical modeling data showing the effect of different fabrication parameters such as structure parameters are also discussed.

Alvine, Kyle J.; Bernacki, Bruce E.; Suter, Jonathan D.; Bennett, Wendy D.; Edwards, Daniel L.; Mendoza, Albert

2013-05-29T23:59:59.000Z

456

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

457

MR imaging techniques for nano-pathophysiology and theranostics  

Science Journals Connector (OSTI)

Abstract The advent of nanoparticle \\{DDSs\\} (drug delivery systems, nano-DDSs) is opening new pathways to understanding physiology and pathophysiology at the nanometer scale. A nano-DDS can be used to deliver higher local concentrations of drugs to a target region and magnify therapeutic effects. However, interstitial cells or fibrosis in intractable tumors, as occurs in pancreatic or scirrhous stomach cancer, tend to impede nanoparticle delivery. Thus, it is critical to optimize the type and size of nanoparticles to reach the target. High-resolution 3D imaging provides a means of “seeing” the nanoparticle distribution and therapeutic effects. We introduce the concept of “nano-pathophysiological imaging” as a strategy for theranostics. The strategy consists of selecting an appropriate nano-DDS and rapidly evaluating drug effects in vivo to guide the next round of therapy. In this article we classify nano-DDSs by component carrier materials and present an overview of the significance of nano-pathophysiological MRI.

Kevin M. Bennett; Jun-ichiro Jo; Horacio Cabral; Rumiana Bakalova; Ichio Aoki

2014-01-01T23:59:59.000Z

458

Mie resonances to tailor random lasers  

SciTech Connect (OSTI)

In this paper, we present an optical characterization of photonic glass-based random lasers. We show how the resonant behavior of diffuse light transport through such systems can tailor the lasing emission when a gain medium is added to the glass. A DNA-based organic dye is used as gain medium. The resonances in the transport mean-free path influence the lasing wavelength of the random laser. The laser wavelength is therefore controlled by the sphere diameter. Furthermore, the existence of Mie resonances reduces the necessary pump energy to reach the lasing threshold.

Garcia, P. D.; Ibisate, M.; Sapienza, R.; Lopez, C. [Instituto de Ciencia de Materiales de Madrid (CSIC) and Unidad Asociada CSIC-UVigo, Cantoblanco, 28049 Madrid (Spain); Wiersma, D. S. [European Laboratory for Nonlinear Spectroscopy and INFM-BEC, Sesto Fiorentino, 50019 Florence (Italy)

2009-07-15T23:59:59.000Z

459

Resonator-quantum well infrared photodetectors  

SciTech Connect (OSTI)

We applied a recent electromagnetic model to design the resonator-quantum well infrared photodetector (R-QWIP). In this design, we used an array of rings as diffractive elements to diffract normal incident light into parallel propagation and used the pixel volume as a resonator to intensify the diffracted light. With a proper pixel size, the detector resonates at certain optical wavelengths and thus yields a high quantum efficiency (QE). To test this detector concept, we fabricated a number of R-QWIPs with different quantum well materials and detector geometries. The experimental result agrees satisfactorily with the prediction, and the highest QE achieved is 71%.

Choi, K. K., E-mail: kwong.k.choi.civ@mail.mil; Sun, J.; Olver, K. [Electro-Optics and Photonics Division, U.S. Army Research Laboratory, Adelphi, Maryland 20783 (United States)] [Electro-Optics and Photonics Division, U.S. Army Research Laboratory, Adelphi, Maryland 20783 (United States); Jhabvala, M. D.; Jhabvala, C. A.; Waczynski, A. [Instrument Systems and Technology Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)] [Instrument Systems and Technology Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2013-11-11T23:59:59.000Z

460

Directional emission from weakly eccentric resonators  

E-Print Network [OSTI]

It is shown that when a circular resonator is deformed in a nonintegrable way, a symmetry breaking of escaping rays occurs which can dramatically modulate the outgoing wave even for small perturbations. The underlying mechanism does not occur in integrable models for which the ray families can be computed exactly and is described in this Letter on the basis of canonical perturbation theory. Emission from deformed resonators is currently of immense practical interest in the context of whispering-gallery optical resonances of dielectric cavities and the approach outlined here promises simple analytical characterisations in the important case of small deformations.

Stephen C Creagh

2007-03-14T23:59:59.000Z

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

Compact RF resonator for cryogenic ion traps  

E-Print Network [OSTI]

We report on the investigation and implementation of a lumped-component, radio-frequency resonator used in a cryogenic vacuum environment to drive an ion trap. The resonator was required to achieve the voltages necessary to trap (about 100 V), while dissipating as little power as possible (< 250 mW). Ultimately a voltage gain of 100 was measured at 5.7 K. Single calcium ions were confined in a trap driven by this device, providing proof of successful resonator operation at low temperature.

D. Gandolfi; M. Niedermayr; M. Kumph; M. Brownnutt; R. Blatt

2012-04-23T23:59:59.000Z

462

Nanometric constrictions in superconducting coplanar waveguide resonators  

E-Print Network [OSTI]

We report on the design, fabrication and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing and electron paramagnetic resonance.

Mark David Jenkins; Uta Naether; Miguel Ciria; Javier Sesé; James Atkinson; Carlos Sánchez-Azqueta; Enrique del Barco; Johannes Majer; David Zueco; Fernando Luis

2014-09-03T23:59:59.000Z

463

Coherence and anticoherence resonance tuned by noise  

Science Journals Connector (OSTI)

We present numerical evidence and a theoretical analysis of the appearance of anticoherence resonance induced by noise, not predicted in former analysis of coherence resonance. We have found that this phenomenon occurs for very small values of the intensity of the noise acting on an excitable system, and we claim that this is a universal signature of a nonmonotonous relaxational behavior near its oscillatory regime. Moreover, we demonstrate that this new phenomenon is totally compatible with the standard situation of coherence resonance appearing at intermediate values of noise intensity.

A. M. Lacasta; F. Sagués; J. M. Sancho

2002-10-24T23:59:59.000Z

464

Cyclotron resonance in plasma flow  

SciTech Connect (OSTI)

This paper is devoted to the mechanism of particle acceleration via resonant interaction with the electromagnetic circular wave propagating along the inhomogeneous background magnetic field in the presence of a plasma flow. We consider the system where the plasma flow velocity is large enough to change the direction of wave propagation in the rest frame. This system mimics a magnetic field configuration typical for inner structure of a quasi-parallel shock wave. We consider conditions of gyroresonant interaction when the force corresponding to an inhomogeneity of the background magnetic field is compensated by the Lorentz force of the wave-magnetic field. The wave-amplitude is assumed to be about 10% of the background magnetic field. We show that particles can gain energy if kv{sub sw}>?>kv{sub sw}??{sub c} where k is the wave number, v{sub sw} is a plasma flow velocity, and ? and ?{sub c} are the wave frequency and the particle gyrofrequency, respectively. This mechanism of acceleration resembles the gyrosurfing mechanism, but the effect of the electrostatic field is replaced by the effect of the magnetic field inhomogeneity.

Artemyev, A. V.; Agapitov, O. V.; Krasnoselskikh, V. V. [LPC2E/CNRS-University of Orleans, Orleans (France)] [LPC2E/CNRS-University of Orleans, Orleans (France)

2013-12-15T23:59:59.000Z

465

millionImaging research infrastructure  

E-Print Network [OSTI]

Centre for Imaging Technology Commercialization, led by Aaron Fenster $34 million Hybrid imaging infrastructureimaging #12;IMAGING Investment $100 millionImaging research infrastructure Formation

Denham, Graham

466

Neurobiology of Disease Cortical Folding Abnormalities in Autism Revealed by  

E-Print Network [OSTI]

-Based Morphometry Christine Wu Nordahl,1 Donna Dierker,2 Iman Mostafavi,1 Cynthia M. Schumann,1,3 Susan M. Rivera,4 from structural magnetic resonance imaging data and compared typically developing controls to three, although structural magnetic resonance imaging (MRI) studies have provided important information about

Van Essen, David

467

Alumnidag 2012 21 april 2012  

E-Print Network [OSTI]

image analysis (ter Haar- Romeny) · Biomodeling & bioinformatics (Hilbers) g g · 3 thematic research programs · Regenerative Medicine · Molecular Imaging · Systems Biology / biomedical engineering PAGE 330 In vivo measurement of metabolites Nuclear Magnetic Resonance · MRI · Nuclear Magnetic Resonance

Franssen, Michael

468

Plutonium less mysterious with nuclear magnetic resonance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

469

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

470

Design guidelines for optical resonator biochemical sensors  

E-Print Network [OSTI]

In this paper, we propose a design tool for dielectric optical resonator-based biochemical refractometry sensors. Analogous to the widely accepted photodetector figure of merit, the detectivity D*, we introduce a new sensor ...

Kimerling, Lionel C.

471

Resonantly pumped optical pumping injection cavity lasers  

E-Print Network [OSTI]

An optical parametric oscillator is tuned to the resonance wavelength of the etalon in an optical pumping injection cavity (OPIC) laser with a type-II "W" active region, thereby minimizing the threshold pump intensity and ...

Santilli, Michael Robert; McAlpine, T. C.; Greene, K. R.; Olafsen, L. J.; Bewley, W. W.; Felix, C. L.; Vurgaftman, I.; Meyer, J. R.; Lee, H.; Martinelli, R. U.

2004-11-01T23:59:59.000Z

472

Vibration Transmission through Symmetric Resonant Couplings  

Science Journals Connector (OSTI)

15 March 1994 research-article Vibration Transmission through Symmetric Resonant Couplings D. J. Allwright...Blakemore P. R. Brazier-Smith J. Woodhouse The transmission of vibration through a symmetric junction is considered. The problem is...

1994-01-01T23:59:59.000Z

473

A transmission calibration method for superconducting resonators  

E-Print Network [OSTI]

A method is proposed and experimentally explored for \\textit{in-situ} calibration of complex transmission data for superconducting microwave resonators. This cryogenic calibration method accounts for the instrumental transmission response between the vector network analyzer reference plane and the device calibration plane. Once calibrated, the observed resonator response was modeled in detail by two approaches. The first, a phenomenological model based on physically realizable rational functions, enables the extraction of multiple resonance frequencies and widths for coupled resonators without explicit specification of the circuit network. In the second, an ABCD-matrix representation for the distributed transmission line circuit is used to model the observed response from the characteristic impedance and propagation constant. When used in conjunction with electromagnetic simulations, the kinetic inductance fraction can be determined with this method with an accuracy of 2%. Datasets for superconducting microst...

Cataldo, Giuseppe; Barrentine, Emily M; Brown, Ari D; Moseley, Samuel H; U-Yen, Kongpop

2014-01-01T23:59:59.000Z

474

THE RESONANT TRANS-NEPTUNIAN POPULATIONS  

SciTech Connect (OSTI)

The trans-Neptunian objects (TNOs) trapped in mean-motion resonances with Neptune were likely emplaced there during planet migration late in the giant-planet formation process. We perform detailed modeling of the resonant objects detected in the Canada-France Ecliptic Plane Survey (CFEPS) in order to provide population estimates and, for some resonances, constrain the complex internal orbital element distribution. Detection biases play a critical role because phase relationships with Neptune make object discovery more likely at certain longitudes. This paper discusses the 3:2, 5:2, 2:1, 3:1, 5:1, 4:3, 5:3, 7:3, 5:4, and 7:4 mean-motion resonances, all of which had CFEPS detections, along with our upper limit on 1:1 Neptune Trojans (which is consistent with their small population estimated elsewhere). For the plutinos (TNOs in the 3:2 resonance) we refine the orbital element distribution given by Kavelaars et al. in 2009 and show that steep H-magnitude distributions (N(H){proportional_to}10{sup {alpha}H}, with {alpha} = 0.8-0.9) are favored in the range H{sub g} = 8-9, and confirm that this resonance does not share the inclination distribution of the classical Kuiper Belt. We give the first population estimate for the 5:2 resonance and find that, to within the uncertainties, the population is equal to that of the 3:2 ({approx_equal}13,000 TNOs with H{sub g} < 9.16), whereas the 2:1 population is smaller by a factor of 3-4 compared to the other two resonances. We also measure significant populations inhabiting the 4:3, 5:3, 7:3, 5:4, 7:4, 3:1, and 5:1 resonances, with H{sub g} < 9.16 (D > 100 km) populations in the thousands. We compare our intrinsic population and orbital element distributions with several published models of resonant-TNO production; the most striking discrepancy is that resonances beyond the 2:1 are in reality more heavily populated than in published models.

Gladman, B.; Lawler, S. M.; Van Laerhoven, C. [Department of Physics and Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Petit, J.-M.; Rousselot, P. [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, 25010 Besancon Cedex (France); Kavelaars, J. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jones, R. L. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Parker, J. Wm.; Bieryla, A. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Nicholson, P. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-07-15T23:59:59.000Z

475

Bayesian analysis of single-subject fMRI data: SPM5 implementation  

E-Print Network [OSTI]

the AR coefficients A. The parameters control the observation noise precision at each voxel. The graph in fMRI (eg. 300- 400 scans) this creates a bottleneck when implementing the algorithm in MATLAB the following cross-covariances. This first set of terms depends on the design matrix only and therefore can

Penny, Will

476

Bayesian fMRI Data Analysis with Sparse Spatial Basis Function Priors  

E-Print Network [OSTI]

Bayesian fMRI Data Analysis with Sparse Spatial Basis Function Priors Guillaume Flandin a,,1 correlation in the data. The spatial aspect of the hemodynamic response is usually taken into account indirectly, i.e. not modelled explicitly, by spatially smoothing the data with a fixed Gaussian kernel

Penny, Will

477

Multimodal EEG, MRI and PET Data Fusion for Alzheimer's Disease Diagnosis  

E-Print Network [OSTI]

in combining EEG, MRI and PET data using an ensemble of classifiers based decision fusion ap- proach using each individual data source. I. INTRODUCTION lhzeimer's disease is a neurodegenerative disorder, causing neuronal death that leads to cognitive function decline. Two misfolded proteins, -amyloid

Polikar, Robi

478

Development/Plasticity/Repair A Structural MRI Study of Human Brain Development from  

E-Print Network [OSTI]

Development/Plasticity/Repair A Structural MRI Study of Human Brain Development from Birth to 2 Carolina, Chapel Hill, North Carolina 27599-7510 Brain development in the first 2 years after birth and schizophrenia. Knowledge regarding this period is currently quite limited. We studied structural brain

Utah, University of

479

Optimization of experimental design in fMRI: a general framework using a genetic algorithm  

E-Print Network [OSTI]

Optimization of experimental design in fMRI: a general framework using a genetic algorithm Tor D uses a genetic algorithm (GA), a class of flexible search algorithms that optimize designs with respect with respect to fitness criteria, allowing optimization over known or novel fitness measures. We describe how

480

The need for clinical quantification of combined PET/MRI data in pediatric epilepsy  

E-Print Network [OSTI]

The need for clinical quantification of combined PET/MRI data in pediatric epilepsy Otto Muzik a,b,n , Darshan Pai c , Csaba Juhasz a , Jing Hua c a Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, USA b Department of Radiology, Wayne State University School of Medicine, Detroit

Hua, Jing

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.


481

SHEARING BOX SIMULATIONS OF THE MRI IN A COLLISIONLESS PLASMA Prateek Sharma and Gregory W. Hammett  

E-Print Network [OSTI]

Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543; psharma@pppl.gov, hammettSHEARING BOX SIMULATIONS OF THE MRI IN A COLLISIONLESS PLASMA Prateek Sharma and Gregory W. Hammett@astron.berkeley.edu and James M. Stone Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544; jstone@astro.princeton

Hammett, Greg

482

Resonant-cavity antenna for plasma heating  

DOE Patents [OSTI]

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

483

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

484

Quantum-secured imaging  

E-Print Network [OSTI]

We have built an imaging system that uses a photon's position or time-of-flight information to image an object, while using the photon's polarization for security. This ability allows us to obtain an image which is secure against an attack in which the object being imaged intercepts and resends the imaging photons with modified information. Popularly known as "jamming," this type of attack is commonly directed at active imaging systems such as radar. In order to jam our imaging system, the object must disturb the delicate quantum state of the imaging photons, thus introducing statistical errors that reveal its activity.

Mehul Malik; Omar S. Magaña-Loaiza; Robert W. Boyd

2012-12-11T23:59:59.000Z

485

Acoustic resonance for nonmetallic mine detection  

SciTech Connect (OSTI)

The feasibility of acoustic resonance for detection of plastic mines was investigated by researchers at the Oak Ridge National Laboratory`s Instrumentation and Controls Division under an internally funded program. The data reported in this paper suggest that acoustic resonance is not a practical method for mine detection. Representative small plastic anti-personnel mines were tested, and were found to not exhibit detectable acoustic resonances. Also, non-metal objects known to have strong acoustic resonances were tested with a variety of excitation techniques, and no practical non-contact method of exciting a consistently detectable resonance in a buried object was discovered. Some of the experimental data developed in this work may be useful to other researchers seeking a method to detect buried plastic mines. A number of excitation methods and their pitfalls are discussed. Excitation methods that were investigated include swept acoustic, chopped acoustic, wavelet acoustic, and mechanical shaking. Under very contrived conditions, a weak response that could be attributed to acoustic resonance was observed, but it does not appear to be practical as a mine detection feature. Transfer properties of soil were investigated. Impulse responses of several representative plastic mines were investigated. Acoustic leakage coupling, and its implications as a disruptive mechanism were investigated.

Kercel, S.W.

1998-04-01T23:59:59.000Z

486

Resonance Absorption and Regeneration in Relativistic Heavy Ion Collisions  

E-Print Network [OSTI]

The regeneration of hadronic resonances is discussed for heavy ion collisions at SPS and SIS-300 energies. The time evolutions of Delta, rho and phi resonances are investigated. Special emphasize is put on resonance regeneration after chemical freeze-out. The emission time spectra of experimentally detectable resonances are explored.

Sascha Vogel; Marcus Bleicher

2005-05-10T23:59:59.000Z

487

EFFECTS OF SENSORI-MOTOR LEARNING ON MELODY PROCESSING ACROSS DEVELOPMENT  

E-Print Network [OSTI]

EFFECTS OF SENSORI-MOTOR LEARNING ON MELODY PROCESSING ACROSS DEVELOPMENT Elizabeth M. WAKEFIELD Resonance Imaging (fMRI) to determine how these melodies are subsequently processed. Results demonstrated in some music education techniques. KEYWORDS: fMRI, visual-motor learning, music, MTG Perception

James, Karin Harman

488

Health Care Manag Sci DOI 10.1007/s10729-011-9153-z  

E-Print Network [OSTI]

and planning prob- lems faced by the Radiology Department concerning MRI examinations. SCH serves pediatric patient demand for examinations on Magnetic Resonance Imaging (MRI) machines at a hospital radiology · Forecasting · Decision support systems · Radiology · Scheduling · Resource planning · Multicriteria

Phillips, David

489

Assessment of rigid multi-modality image registration consistency using the multiple sub-volume registration (MSR) method  

Science Journals Connector (OSTI)

Registration of different imaging modalities such as CT, MRI, functional MRI (fMRI), positron (PET) and single photon (SPECT) emission tomography is used in many clinical applications. Determining the quality of any automatic registration procedure has been a challenging part because no gold standard is available to evaluate the registration. In this note we present a method, called the 'multiple sub-volume registration' (MSR) method, for assessing the consistency of a rigid registration. This is done by registering sub-images of one data set on the other data set, performing a crude non-rigid registration. By analysing the deviations (local deformations) of the sub-vol