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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,
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We encourage you to perform a real-time search of NLEBeta
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1

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...

2

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

3

Single echo acquisition magnetic resonance imaging  

E-Print Network [OSTI]

The dramatic improvement in magnetic resonance imaging (MRI) scan time over the past fifteen years through gradient-based methods that sample k-space more efficiently and quickly cannot be sustained, as thresholds regarding hardware and safety...

McDougall, Mary Preston

2006-04-12T23:59:59.000Z

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  

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 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

7

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

8

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

9

RF Pulse Design for Parallel Excitation in Magnetic Resonance Imaging  

E-Print Network [OSTI]

Parallel excitation is an emerging technique to improve or accelerate multi-dimensional spatially selective excitations in magnetic resonance imaging (MRI) using multi-channel transmit arrays. The technique has potential in many applications...

Liu, Yinan

2012-07-16T23:59:59.000Z

10

Modeling Left Ventricle Wall Motion Using Tagged Magnetic Resonance Imaging  

E-Print Network [OSTI]

A two-parameter computational model is proposed for the study of the regional motion of the left ventricle (LV) wall using tagged magnetic resonance imaging (tMRI) data. In this model, the LV wall motion is mathematically ...

Alenezy, Mohammed D.

2009-04-17T23:59:59.000Z

11

Improvements in magnetic resonance imaging excitation pulse design  

E-Print Network [OSTI]

This thesis focuses on the design of magnetic resonance imaging (MRI) radio-frequency (RF) excitation pulses, and its primary contributions are made through connections with the novel multiple-system single-output (MSSO) ...

Zelinski, Adam Charles

2008-01-01T23:59:59.000Z

12

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

13

3D RECONSTRUCTION OF PLANT ROOTS FROM MRI IMAGES Hannes Schulz1  

E-Print Network [OSTI]

distance measure by a multi-scale vesselness measure. As a result, paths running within good root candidates are preferred over paths in bare soil. We test this method using both virtually generated MRI) and Nuclear Magnetic Resonance Imaging (MRI) (Brown et al., 1990; Jahnke et al., 2009; Southon and Jones, 1992

Behnke, Sven

14

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

15

Plant root system analysis from MRI images Hannes Schulz1, Johannes A. Postma2, Dagmar van Dusschoten2,  

E-Print Network [OSTI]

voxel to the base of the plant root, weighing the Euclidean distance measure by a multi-scale vesselness test this method using both virtually generated MRI images of Maize and real MRI images of Barley roots (Ferreira et al., 2010; Nakanishi et al., 2003; Pierret et al., 2003) and Nuclear Magnetic Resonance Imaging

Behnke, Sven

16

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

17

E-Print Network 3.0 - ablation assisted resonance Sample Search...  

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

enhancement (LGE) mag- netic resonance imaging (MRI) immediately post-ablation (IPA... enhancement MRI magnetic resonance imaging NE nonenhancing RF radiofrequency RFA...

18

Respiratory Amplitude Guided 4-Dimensional Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Purpose: To evaluate the feasibility of prospectively guiding 4-dimensional (4D) magnetic resonance imaging (MRI) image acquisition using triggers at preselected respiratory amplitudes to achieve T{sub 2} weighting for abdominal motion tracking. Methods and Materials: A respiratory amplitude-based triggering system was developed and integrated into a commercial turbo spin echo MRI sequence. Initial feasibility tests were performed on healthy human study participants. Four respiratory states, the middle and the end of inhalation and exhalation, were used to trigger 4D MRI image acquisition of the liver. To achieve T{sub 2} weighting, the echo time and repetition time were set to 75 milliseconds and 4108 milliseconds, respectively. Single-shot acquisition, together with parallel imaging and partial k-space imaging techniques, was used to improve image acquisition efficiency. 4D MRI image sets composed of axial or sagittal slices were acquired. Results: Respiratory data measured and logged by the MRI scanner showed that the triggers occurred at the appropriate respiratory levels. Liver motion could be easily observed on both 4D MRI image datasets by sensing either the change of liver in size and shape (axial) or diaphragm motion (sagittal). Both 4D MRI image datasets were T{sub 2}-weighted as expected. Conclusions: This study demonstrated the feasibility of achieving T{sub 2}-weighted 4D MRI images using amplitude-based respiratory triggers. With the aid of the respiratory amplitude-based triggering system, the proposed method is compatible with most MRI sequences and therefore has the potential to improve tumor-tissue contrast in abdominal tumor motion imaging.

Hu, Yanle, E-mail: yhu@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)] [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Caruthers, Shelton D. [Department of Medicine, Washington University School of Medicine, St. Louis, Missouri (United States)] [Department of Medicine, Washington University School of Medicine, St. Louis, Missouri (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States)] [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Parikh, Parag J.; Mutic, Sasa [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)] [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)

2013-05-01T23:59:59.000Z

19

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

20

Improvements in Low Field MRI  

E-Print Network [OSTI]

The world of clinical magnetic resonance imaging (MRI) is presently dominated by multi-million dollar machines that use large superconducting magnets to generate very high quality images. It is possible to perform MRI at lower magnetic field...

Ogier, Stephen E

2013-02-01T23:59:59.000Z

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


21

Original Research In Vivo Magnetic Resonance Imaging of the Human  

E-Print Network [OSTI]

Original Research In Vivo Magnetic Resonance Imaging of the Human Cervical Spinal Cord at 3 Tesla is feasible at 3 T. Key Words: MRI; 3 Tesla; cervical spinal cord; gradient echo; gray matter; white matter J, and pulsatile flow (9,10). Deficits in motor and sensory function from damage to the spinal cord are mainly due

Gorassini, Monica

22

A pulsed electromagnet controller for prepolarized MRI  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) is a popular medical imaging modality that provides high resolution images with superior contrast. Conventional MRI systems rely on large magnets to generate the main magnetic field, B?, that is both strong...

Nam, Hyokwon

2001-01-01T23:59:59.000Z

23

An iterative technique for refinement of selective excitations for magnetic resonance imaging  

E-Print Network [OSTI]

Selective RF pulses are needed or many application in magnetic resonance imaging (MRI). The desired excitation profile is omen used as the spectrum of the applied RF pulse; the modulation waveform of the RF pulse which approximately excites...

Lebsack, Eliot Todd

1999-01-01T23:59:59.000Z

24

Eight-Channel Head Array and Control System for Parallel Transmit/Receive Magnetic Resonance Imaging  

E-Print Network [OSTI]

Interest in magnetic resonance imaging (MRI) at high fields strengths (3 Tesla and above) is driven by the associated improvements in signal-to-noise ratio and spectral resolution. In practice, however, technical challenges prevent these benefits...

Moody, Katherine

2014-08-11T23:59:59.000Z

25

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

E-Print Network [OSTI]

Breast cancer is the second leading cause of cancer death among females in the United States. Magnetic resonance imaging (MRI) has emerged as a powerful tool for detecting and evaluating the disease, with notable advantages over other modalities...

By, Samantha

2014-04-01T23:59:59.000Z

26

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

E-Print Network [OSTI]

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

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

2005-01-01T23:59:59.000Z

27

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

28

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

29

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

30

Chapter 20. Magnetic Resonance Imaging Magnetic Resonance Imaging  

E-Print Network [OSTI]

, and software training from Siemens Medical Solutions; research funding through the Siemens-MIT Alliance and Technology (HST). 2 Siemens Medical Solutions, Erlangen, Germany. #12;Chapter 20. Magnetic Resonance Imaging, Siemens Medical Solutions, Siemens-MIT Alliance, HST Martinos Catalyst Fund. Project Staff: Audrey P. Fan

31

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

32

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

33

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

34

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

35

Abstract-In this study, imaging of electrical current density in conducting objects, which contain nuclear magnetic resonance  

E-Print Network [OSTI]

nuclear magnetic resonance (NMR) active nuclei is planned using 0.15T Magnetic Resonance Imaging (MRI at each cycle within the object. The applied current pulse creates a measurable magnetic flux density. The component of magnetic flux density parallel to the main magnetic field accumulates an additional phase

Eyüboðlu, Murat

36

E-Print Network 3.0 - automated image analysis1woa Sample Search...  

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... Resonance Imaging (MRI) has largely been used for...

37

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.

38

fMRI Brain Image Retrieval Based on ICA Components bbai@cs.rutgers.edu  

E-Print Network [OSTI]

fMRI Brain Image Retrieval Based on ICA Components Bing Bai bbai@cs.rutgers.edu Department This manuscript proposes a retrieval system for fMRI brain images. Our goal is to find a similarity- metric to enable us to support queries for "similar tasks" for retrieval on a large collection of brain ex

39

Cardiac Magnetic Resonance Imaging Findings in 20-year Survivors of Mediastinal Radiotherapy for Hodgkin's Disease  

SciTech Connect (OSTI)

Purpose: The recognition of the true prevalence of cardiac toxicity after mediastinal radiotherapy requires very long follow-up and a precise diagnostic procedure. Cardiac magnetic resonance imaging (MRI) permits excellent quantification of cardiac function and identification of localized myocardial defects and has now been applied to a group of 20-year Hodgkin's disease survivors. Methods and materials: Of 143 patients treated with anterior mediastinal radiotherapy (cobalt-60, median prescribed dose 40 Gy) for Hodgkin's disease between 1978 and 1985, all 53 survivors were invited for cardiac MRI. Of those, 36 patients (68%) presented for MRI, and in 31 patients (58%) MRI could be performed 20-28 years (median, 24) after radiotherapy. The following sequences were acquired on a 1.5-T MRI: transversal T1-weighted TSE and T2-weighted half-fourier acquisition single-shot turbo-spin-echo sequences, a steady-state free precession (SSFP) cine sequence in the short heart axis and in the four-chamber view, SSFP perfusion sequences under rest and adenosine stress, and a SSFP inversion recovery sequence for late enhancement. The MRI findings were correlated with previously reconstructed doses to cardiac structures. Results: Clinical characteristics and reconstructed doses were not significantly different between survivors undergoing and not undergoing MRI. Pathologic findings were reduced left ventricular function (ejection fraction <55%) in 7 (23%) patients, hemodynamically relevant valvular dysfunction in 13 (42%), late myocardial enhancement in 9 (29%), and any perfusion deficit in 21 (68%). An association of regional pathologic changes and reconstructed dose to cardiac structures could not be established. Conclusions: In 20-year survivors of Hodgkin's disease, cardiac MRI detects pathologic findings in approximately 70% of patients. Cardiac MRI has a potential role in cardiac imaging of Hodgkin's disease patients after mediastinal radiotherapy.

Machann, Wolfram; Beer, Meinrad [Department of Radiology, University of Wuerzburg (Germany); Breunig, Margret; Stoerk, Stefan; Angermann, Christiane [Department of Cardiology, University of Wuerzburg (Germany); Seufert, Ines; Schwab, Franz; Koelbl, Oliver; Flentje, Michael [Department of Radiation Oncology, University of Wuerzburg (Germany); Vordermark, Dirk, E-mail: dirk.vordermark@medizin.uni-halle.d [Department of Radiation Oncology, University of Wuerzburg (Germany); Department of Radiation Oncology, Martin Luther University Halle-Wittenberg (Germany)

2011-03-15T23:59:59.000Z

40

Preliminary tests using magnetic resonance imaging of two-phase flow patterns and transitions  

SciTech Connect (OSTI)

This paper presents the results of preliminary tests used to establish the feasibility of using magnetic resonance imaging (MRI) to examine and quantitatively characterize two-phase flow patterns and flow transitions. These tests were performed at the University of California, San Francisco (UCSF) School of Medicine MRI Center as a collaborative research effort with Oregon State University (OSU). Special scanning sequences designed by UCSF for flow imaging were implemented in the tests. UCSF operated the MRI facility, and OSU constructed and operated a cocurrent air-water flow loop consisting of a 1-in.-diam test section capable of producing air superficial velocities j[sub g] ranging from 0.3 to 14 m/s, and water superficial velocities j[sub l] ranging from 0.08 to 1.3 m/s.

Reyes, J.N. Jr.; Lafi, A.Y. (Oregon State Univ., Corvallis, OR (United States)); Saloner, D. (Univ. of California, San Francisco, CA (United States))

1993-01-01T23:59:59.000Z

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

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

42

Potential Applications of Microtesla Magnetic Resonance ImagingDetected Using a Superconducting Quantum Interference Device  

SciTech Connect (OSTI)

This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 {micro}T. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz{sup -1/2} referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm{sup 3} resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm{sup 3} images of bell peppers and 3 x 3 x 26 mm{sup 3} in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T{sub 1}) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The measured T{sub 1} of ex vivo normal and cancerous prostate tissue differ significantly at 132 {micro}T. A single-sided MRI system designed for prostate imaging could achieve 3 x 3 x 5 mm{sup 3} resolution in 8 minutes. Existing SQUID-based magnetoencephalography (MEG) systems could be used as microtesla MRI detectors. A commercial 275-channel MEG system could acquire 6-minute brain images with (4 mm){sup 3} resolution and SNR 16.

Myers, Whittier R.

2006-05-18T23:59:59.000Z

43

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

44

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

45

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...

46

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

DOE Patents [OSTI]

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

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

2009-08-11T23:59:59.000Z

47

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

48

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

49

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

50

Magnetic resonance spectroscopic imaging using parallel transmission at 7T  

E-Print Network [OSTI]

Conventional magnetic resonance spectroscopic imaging (MRSI), also known as phase-encoded (PE) chemical shift imaging (CSI), suffers from both low signal-to-noise ratio (SNR) of the brain metabolites, as well as inflexible ...

Gagoski, Borjan Aleksandar

2011-01-01T23:59:59.000Z

51

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and InterfacesAdministration -Lowell L.FallU . SChromatography

52

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

53

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

SciTech Connect (OSTI)

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

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

2012-02-15T23:59:59.000Z

54

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

55

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

56

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.

57

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

SciTech Connect (OSTI)

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

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

2012-06-15T23:59:59.000Z

58

Use of Non-Invasive Phase Contrast Magnetic Resonance Imaging for Estimation of Atrial Septal Defect Size and Morphology: A Comparison with Transesophageal Echo  

SciTech Connect (OSTI)

Background: Transesophageal echocardiography (TEE) is a trusted method of sizing atrial septal defect (ASD) prior to percutaneous closure but is invasive, uncomfortable, and may carry a small risk of morbidity and mortality. Magnetic resonance imaging (MRI) may be useful non-invasive alternative in such patients who refuse or are unable to tolerate TEE and may provide additional information on the shape of the A0SD. Purpose: To validate the accuracy of ASD sizing by MRI compared with TEE.Method: Twelve patients (mean age 30 years; range 11-60 years) scheduled for ASD closure underwent TEE, cine balanced fast field echo MRI (bFFE-MRI) in four-chamber and sagittal views and phase-contrast MRI (PC-MRI) with reconstruction using the two orthogonal planes of T2-weighted images as planning. The average of the three longest measurements for all imaging modalities was calculated for each patient. Results: Mean maximum ASD length on TEE was 18.8 {+-} 4.6 mm, mean length by bFFE-MRI was 20.0 {+-} 5.0 mm, and mean length by PC-MRI was 18.3 {+-} 3.6 mm. The TEE measurement was significantly correlated with the bFFE-MRI and PC-MRI measurements (Pearson r = 0.69, p = 0.02 and r = 0.59, p = 0.04, respectively). The mean difference between TEE and bFFE-MRI measurements was -1.2mm (95% CI: -3.7, 1.3) and between TEE and PC-MRI was 0.5 mm (95% CI: -1.9, 2.9). Bland-Altman analysis also determined general agreement between both MRI methods and TEE. The ASDs were egg-shaped in two cases, circular in 1 patient and oval in the remaining patients. Conclusion: ASD sizing by MRI using bFFE and phase-contrast protocols correlated well with TEE estimations. PC-MRI provided additional information on ASD shapes and proximity to adjacent structures.

Piaw, Chin Sze; Kiam, Ong Tiong [Sarawak General Hospital, Department of Cardiology (Malaysia); Rapaee, Annuar [University of Malaysia Sarawak (Malaysia)], E-mail: rannuar@fmhs.unimas.myp; Khoon, Liew Chee; Bang, Liew Houng; Ling, Chan Wei [Sarawak General Hospital, Department of Cardiology (Malaysia); Samion, Hasri [National Heart Institute, Pediatric of Cardiology (Malaysia); Hian, Sim Kui [Sarawak General Hospital, Department of Cardiology (Malaysia)

2006-04-15T23:59:59.000Z

59

Radiation-Induced Alterations in Mouse Brain Development Characterized by Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Purpose: The purpose of this study was to identify regions of altered development in the mouse brain after cranial irradiation using longitudinal magnetic resonance imaging (MRI). Methods and Materials: Female C57Bl/6 mice received a whole-brain radiation dose of 7 Gy at an infant-equivalent age of 2.5 weeks. MRI was performed before irradiation and at 3 time points following irradiation. Deformation-based morphometry was used to quantify volume and growth rate changes following irradiation. Results: Widespread developmental deficits were observed in both white and gray matter regions following irradiation. Most of the affected brain regions suffered an initial volume deficit followed by growth at a normal rate, remaining smaller in irradiated brains compared with controls at all time points examined. The one exception was the olfactory bulb, which in addition to an early volume deficit, grew at a slower rate thereafter, resulting in a progressive volume deficit relative to controls. Immunohistochemical assessment revealed demyelination in white matter and loss of neural progenitor cells in the subgranular zone of the dentate gyrus and subventricular zone. Conclusions: MRI can detect regional differences in neuroanatomy and brain growth after whole-brain irradiation in the developing mouse. Developmental deficits in neuroanatomy persist, or even progress, and may serve as useful markers of late effects in mouse models. The high-throughput evaluation of brain development enabled by these methods may allow testing of strategies to mitigate late effects after pediatric cranial irradiation.

Gazdzinski, Lisa M.; Cormier, Kyle [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada)] [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Lu, Fred G. [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada)] [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Lerch, Jason P. [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada) [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada) [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Nieman, Brian J., E-mail: bjnieman@phenogenomics.ca [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada)

2012-12-01T23:59:59.000Z

60

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

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61

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.

62

Comparison of MRI-based and CT/MRI fusion-based postimplant dosimetric analysis of prostate brachytherapy  

SciTech Connect (OSTI)

Purpose: The aim of this study was to compare the outcomes between magnetic resonance imaging (MRI)-based and computed tomography (CT)/MRI fusion-based postimplant dosimetry methods in permanent prostate brachytherapy. Methods and Materials: Between October 2004 and March 2006, a total of 52 consecutive patients with prostate cancer were treated by brachytherapy, and postimplant dosimetry was performed using CT/MRI fusion. The accuracy and reproducibility were prospectively compared between MRI-based dosimetry and CT/MRI fusion-based dosimetry based on the dose-volume histogram (DVH) related parameters as recommended by the American Brachytherapy Society. Results: The prostate volume was 15.97 {+-} 6.17 cc (mean {+-} SD) in MRI-based dosimetry, and 15.97 {+-} 6.02 cc in CT/MRI fusion-based dosimetry without statistical difference. The prostate V100 was 94.5% and 93.0% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.002). The prostate D90 was 119.4% and 114.4% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.004). Conclusion: Our current results suggested that, as with fusion images, MR images allowed accurate contouring of the organs, but they tended to overestimate the analysis of postimplant dosimetry in comparison to CT/MRI fusion images. Although this MRI-based dosimetric discrepancy was negligible, MRI-based dosimetry was acceptable and reproducible in comparison to CT-based dosimetry, because the difference between MRI-based and CT/MRI fusion-based results was smaller than that between CT-based and CT/MRI fusion-based results as previously reported.

Tanaka, Osamu [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan)]. E-mail: osa-mu@umin.ac.jp; Hayashi, Shinya [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Matsuo, Masayuki [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Sakurai, Kota [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Department of Urology, Gifu University School of Medicine, Gifu City (Japan); Nakano, Masahiro [Department of Urology, Gifu University School of Medicine, Gifu City (Japan); Maeda, Sunaho [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Kajita, Kimihiro R.T. [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Deguchi, Takashi [Department of Urology, Gifu University School of Medicine, Gifu City (Japan); Hoshi, Hiroaki [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan)

2006-10-01T23:59:59.000Z

63

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

64

Parallel magnetic resonance imaging: characterization and comparison  

E-Print Network [OSTI]

[Sodickson, 1997], GRAPPA [Griswold, 2002] and SPACE RIP [Kyriakos, 2000]; developed in the past decade have been studied, simulated and compared in this research. Because of the dependence of the parallel imaging methods on numerous factors such as receiver...

Rane, Swati Dnyandeo

2005-11-01T23:59:59.000Z

65

Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging  

SciTech Connect (OSTI)

Purpose: To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials: Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results: There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions: This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which could aid in individualizing therapy, particularly for patients at risk for liver injury after RT.

Cao Yue, E-mail: yuecao@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Wang Hesheng [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Johnson, Timothy D. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Pan, Charlie [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Hussain, Hero [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

2013-01-01T23:59:59.000Z

66

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

67

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 (2.54 cm fields-of view) at low magnetic field strengths (25 T). The performance of the prototype was verified through bench...

Brown, David Gerald

2007-04-25T23:59:59.000Z

68

Original Research Magnetic Resonance Image-Guided Trans-Septal  

E-Print Network [OSTI]

vasculature. Key Words: interventional; magnetic resonance imaging; trans-septal catheterization; cardiac; MR with a pigtail catheter in the aorta and the use of His bundle/coronary sinus catheters (1), and, more recently from a percutaneous femoral vein ap- proach. MATERIALS AND METHODS Animal Model The Institutional

Atalar, Ergin

69

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

70

Application of Parallel Imaging to Murine Magnetic Resonance Imaging  

E-Print Network [OSTI]

. This dissertation describes foundational level work to enable parallel imaging of mice on a 4.7 Tesla/40 cm bore research scanner. Reducing the size of the hardware setup associated with typical parallel imaging was an integral part of achieving the work, as animal...

Chang, Chieh-Wei 1980-

2012-09-21T23:59:59.000Z

71

Numerical field simulation for parallel transmission in MRI at 7 tesla  

E-Print Network [OSTI]

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

Bernier, Jessica A. (Jessica Ashley)

2011-01-01T23:59:59.000Z

72

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

73

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...

74

An analysis of the PERL Magnetic Resonance Imaging theory and implementation  

E-Print Network [OSTI]

The goal of PERL MRI in its most basic form is single shot imaging without the need to rapidly switch gradients to encode spatial information into the signal. PERL MRI incorporates the application of the PERL field into the standard spin echo...

Kremkus, Mark Christian

2013-02-22T23:59:59.000Z

75

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

E-Print Network [OSTI]

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

Zakszewski, Elizabeth K

2006-01-01T23:59:59.000Z

76

Real-Time Color-Flow Magnetic ResonanceImaging of Congenital Heart Disease E. De La Pena-Almaguer, K. S. Nayak, M. Terashima, P.C. Yang,  

E-Print Network [OSTI]

Real-Time Color-Flow Magnetic ResonanceImaging of Congenital Heart Disease E. De La Pena used for the diagnosis of congenital heart disease (CHD), although it has limitations. Conventional MRI flow pulse sequence.A low flip- angle water selective spectral-spatial excitation is followed

Southern California, University of

77

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'

78

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.

79

Adaptive processing of thin structures to augment segmentation of dual-channel structural MRI of the human brain   

E-Print Network [OSTI]

This thesis presents a method for the segmentation of dual-channel structural magnetic resonance imaging (MRI) volumes of the human brain into four tissue classes. The state-of-the-art FSL FAST segmentation software ...

Withers, James

2010-01-01T23:59:59.000Z

80

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

SciTech Connect (OSTI)

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

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

2012-02-15T23:59:59.000Z

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

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

82

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

83

Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Purpose: Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials: mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results: Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions: Muscles of both the suprahyoid and the longitudinal pharyngeal muscle groups are active in swallowing, and both swallowing exercises effectively target muscles elevating the hyolaryngeal complex. mfMRI is useful in testing swallowing muscle function.

Pearson, William G., E-mail: bp1@bu.edu [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States); Hindson, David F. [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States)] [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States); Langmore, Susan E. [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States) [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States); Speech and Hearing Sciences, Boston University, Boston, Massachusetts (United States); Zumwalt, Ann C. [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)] [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)

2013-03-01T23:59:59.000Z

84

“Calm Down Dear, It’s Only a Simulator.” An investigation into the effects of the fMRI environment on cognition.   

E-Print Network [OSTI]

Functional Magnetic Resonance Imaging (fMRI) is a useful tool which permits the observation of the brain’s neuronal activity in a non-invasive, on-line manner. The usefulness of the technique has however been questioned ...

Black, Ashley Anne

2007-01-01T23:59:59.000Z

85

Magnetic Resonance Imaging 1 A new global optimization algorithm and its application to a  

E-Print Network [OSTI]

Magnetic Resonance Imaging 1 A new global optimization algorithm and its application to a Magnetic-cost, low-field multipolar magnet for Magnetic Resonance Imaging with a high field uniformity, the proposed method em- ploys, as local search engine, a derivative free procedure. Under reasonable

Neumaier, Arnold

86

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

87

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

88

Portable MRI  

SciTech Connect (OSTI)

This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

Espy, Michelle A. [Los Alamos National Laboratory

2012-06-29T23:59:59.000Z

89

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

90

The use of MRI to observe fractures in concrete E. Marfisi*, C. J. Burgoyne*, M. H. G. Amin and L. D. Hall  

E-Print Network [OSTI]

of aggregate can clearly be seen. The third paper 2 reports on the testing of a rein- forced concrete beamThe use of MRI to observe fractures in concrete E. Marfisi*, C. J. Burgoyne*, M. H. G. Amin and L resonance imaging (MRI) of water allows the internal crack pattern of hardened concrete to be observed along

Burgoyne, Chris

91

A practical acceleration algorithm for real-time imaging  

E-Print Network [OSTI]

A practical acceleration algorithm for real-time magnetic resonance imaging (MRI) is presented. Neither separate training scans nor embedded training samples are used. The Kalman filter based algorithm provides a fast and ...

Sumbul, Uygar

92

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.

93

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

94

Highly Parallel Magnetic Resonance Imaging with a Fourth Gradient Channel for Compensation of RF Phase Patterns  

E-Print Network [OSTI]

A fourth gradient channel was implemented to provide slice dependent RF coil phase compensation for arrays in dual-sided or "sandwich" configurations. The use of highly parallel arrays for single echo acquisition magnetic resonance imaging allows...

Bosshard, John 1983-

2012-08-20T23:59:59.000Z

95

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

96

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

E-Print Network [OSTI]

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

Gollub, Randy L.

97

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

E-Print Network [OSTI]

THE DEVELOPMENT OF MAGNETIC RESONANCE IMAGING FOR THE DETERMINATION OF POROSITY IN RESERVOIR CORE SAMPLES A Thesis by BYRON BLAKE SHERMAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1991 Major Subject: Petroleum Engineering THE DEVELOPMENT OF MAGNETIC RESONANCE IMAGING FOR THE DETERMINATION OF POROSITY IN RESERVOIR CORE SAMPLES A Thesis by BYRON BLAKE SHERMAN Approved...

Sherman, Byron Blake

1991-01-01T23:59:59.000Z

98

Application of nuclear magnetic resonance imaging and spectroscopy to fluids in porous media  

E-Print Network [OSTI]

APPLICATION OF NUCLEAR MAGNETIC RESONANCE IMAGING AND SPECTROSCOPY TO FLUIDS IN POROUS MEDIA A Thesis by SHANTHI SREE MANDAVA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1991 Major Subject: Chemical Engineering APPLICATION OF NUCLEAR MAGNETIC RESONANCE IMAGING AND SPECTROSCOPY TO FLUIDS IN POROUS MEDIA A Thesis by SHANTHI SREE MANDAVA Approved as to style and content by: A. Ted...

Mandava, Shanthi Sree

1991-01-01T23:59:59.000Z

99

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

100

Quantitative Clinical Evaluation of a Simultaneous PETI MRI Breast Imaging System  

SciTech Connect (OSTI)

A prototype simultaneous PET-MRI breast scanner has been developed for conducting clinical studies with the goal of obtaining high resolution anatomical and functional information in the same scan which can lead to faster and better diagnosis, reduction of unwanted biopsies, and better patient care.

Schlyer D. J.; Schlyer, D.J.

2013-04-03T23:59:59.000Z

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

Intensity inhomogeneity correction for magnetic resonance imaging of human brain at 7T  

SciTech Connect (OSTI)

Purpose: To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm. Materials: Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D time-of-flight) by using a 7T MRI system. Intensity inhomogeneity correction was performed using the “New Segment” module in SPM8 with four different values (120, 90, 60, and 30 mm) of full width at half maximum (FWHM) in Gaussian smoothness. The uniformity in signals in the entire white matter was evaluated using the coefficient of variation (CV); mean signal intensities between the subcortical and deep white matter were compared, and contrast between subcortical white matter and gray matter was measured. The length of the lenticulostriate (LSA) was measured on maximum intensity projection (MIP) images in the original and corrected images. Results: In all sequences, the CV decreased as the FWHM value decreased. The differences of mean signal intensities between subcortical and deep white matter also decreased with smaller FWHM values. The contrast between white and gray matter was maintained at all FWHM values. LSA length was significantly greater in corrected MIP than in the original MIP images. Conclusions: Intensity inhomogeneity in 7T MRI can be successfully corrected using SPM8 for various scan sequences.

Uwano, Ikuko; Yamashita, Fumio; Higuchi, Satomi; Ito, Kenji; Sasaki, Makoto [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694 (Japan)] [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694 (Japan); Kudo, Kohsuke, E-mail: kkudo@huhp.hokudai.ac.jp; Goodwin, Jonathan; Harada, Taisuke [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694, Japan and Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido 060-8648 (Japan)] [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694, Japan and Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido 060-8648 (Japan); Ogawa, Akira [Department of Neurosurgery, Iwate Medical University, Morioka, Iwate 020-8505 (Japan)] [Department of Neurosurgery, Iwate Medical University, Morioka, Iwate 020-8505 (Japan)

2014-02-15T23:59:59.000Z

102

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

103

Cerebral edema induced in mice by a convulsive dose of soman. Evaluation through diffusion-weighted magnetic resonance imaging and histology  

SciTech Connect (OSTI)

Purpose: In the present study, diffusion-weighted magnetic resonance imaging (DW-MRI) and histology were used to assess cerebral edema and lesions in mice intoxicated by a convulsive dose of soman, an organophosphate compound acting as an irreversible cholinesterase inhibitor. Methods: Three hours and 24 h after the intoxication with soman (172 {mu}g/kg), the mice were anesthetized with an isoflurane/N{sub 2}O mixture and their brain examined with DW-MRI. After the imaging sessions, the mice were sacrificed for histological analysis of their brain. Results: A decrease in the apparent diffusion coefficient (ADC) was detected as soon as 3 h after the intoxication and was found strongly enhanced at 24 h. A correlation was obtained between the ADC change and the severity of the overall brain damage (edema and cellular degeneration): the more severe the damage, the stronger the ADC drop. Anesthesia was shown to interrupt soman-induced seizures and to attenuate edema and cell change in certain sensitive brain areas. Finally, brain water content was assessed using the traditional dry/wet weight method. A significant increase of brain water was observed following the intoxication. Conclusions: The ADC decrease observed in the present study suggests that brain edema in soman poisoning is mainly intracellular and cytotoxic. Since entry of water into Brain was also evidenced, this type of edema is certainly mixed with others (vasogenic, hydrostatic, osmotic). The present study confirms the potential of DW-MRI as a non-invasive tool for monitoring the acute neuropathological consequences (edema and neurodegeneration) of soman-induced seizures.

Testylier, Guy [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France)]. E-mail: guytestylier@crssa.net; Lahrech, Hana [Inserm, UMR-S 836-Grenoble Institut des Neurosciences, Grenoble, F-38043 (France); Universite Joseph Fourier, Grenoble, F-38043 (France); Montigon, Olivier [Inserm, UMR-S 836-Grenoble Institut des Neurosciences, Grenoble, F-38043 (France); Universite Joseph Fourier, Grenoble, F-38043 (France); Foquin, Annie [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Delacour, Claire [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Bernabe, Denis [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Segebarth, Christoph [Inserm, UMR-S 836-Grenoble Institut des Neurosciences, Grenoble, F-38043 (France); Universite Joseph Fourier, Grenoble, F-38043 (France); Dorandeu, Frederic [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Carpentier, Pierre [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France)

2007-04-15T23:59:59.000Z

104

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

105

Fast and contrast-enhanced phase-sensitive magnetic resonance imaging  

E-Print Network [OSTI]

two signals if the resonance frequencies are close. For example, in MR mammography, it is difficult to separate silicone breast implants signals (4.0 ppm) from fat signals (3.5 ppm); (2) the signal dynamic range of images acquired using Dixon...

Son, Jong Bum

2009-05-15T23:59:59.000Z

106

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

107

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

108

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

109

Nuclear magnetic resonance imaging of water content in the subsurface  

SciTech Connect (OSTI)

Previous theoretical and experimental studies indicated that surface nuclear magnetic resonance (NMR) has the potential to provide cost-effective water content measurements in the subsurface and is a technology ripe for exploitation in practice. The objectives of this investigation are (a) to test the technique under a wide range of hydrogeological conditions and (b) to generalize existing NMR theories in order to correctly model NMR response from conductive ground and to assess properties of the inverse problem. Twenty-four sites with different hydrogeologic settings were selected in New Mexico and Colorado for testing. The greatest limitation of surface NMR technology appears to be the lack of understanding in which manner the NMR signal is influenced by soil-water factors such as pore size distribution, surface-to-volume ratio, paramagnetic ions dissolved in the ground water, and the presence of ferromagnetic minerals. Although the theoretical basis is found to be sound, several advances need to be made to make surface NMR a viable technology for hydrological investigations. There is a research need to investigate, under controlled laboratory conditions, how the complex factors of soil-water systems affect NMR relaxation times.

J. Hendricks; T. Yao; A. Kearns

1999-01-21T23:59:59.000Z

110

An RF dosimeter for independent SAR measurement in MRI scanners  

SciTech Connect (OSTI)

Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ?3%. With the torso landmarked at the xiphoid, human adult whole?body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.

Qian, Di; Bottomley, Paul A. [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); El-Sharkawy, AbdEl-Monem M.; Edelstein, William A., E-mail: w.edelstein@gmail.com [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 (United States)

2013-12-15T23:59:59.000Z

111

Small animal simultaneous PET/MRI: initial experiences in a 9.4T microMRI  

SciTech Connect (OSTI)

We developed a non-magnetic positron-emission tomography (PET) device based on the rat conscious animal PET that operates in a small-animal magnetic resonance imaging (MRI) scanner, thereby enabling us to carry out simultaneous PET/MRI studies. The PET detector comprises 12 detector blocks, each being a 4 x 8 array of lutetium oxyorthosilicate crystals (2.22 x 2.22 x 5 mm{sup 3}) coupled to a matching non-magnetic avalanche photodiode array. The detector blocks, housed in a plastic case, form a 38 mm inner diameter ring with an 18 mm axial extent. Custom-built MRI coils fit inside the positron-emission tomography (PET) device, operating in transceiver mode. The PET insert is integrated with a Bruker 9.4 T 210 mm clear-bore diameter MRI scanner. We acquired simultaneous PET/MR images of phantoms, of in vivo rat brain, and of cardiac-gated mouse heart using [{sup 11}C]raclopride and 2-deoxy-2-[{sup 18}F]fluoro-d-glucose PET radiotracers. There was minor interference between the PET electronics and the MRI during simultaneous operation, and small effects on the signal-to-noise ratio in the MR images in the presence of the PET, but no noticeable visual artifacts. Gradient echo and high-duty-cycle spin echo radio frequency (RF) pulses resulted in a 7% and a 28% loss in PET counts, respectively, due to high PET counts during the RF pulses that had to be gated out. The calibration of the activity concentration of PET data during MR pulsing is reproducible within less than 6%. Our initial results demonstrate the feasibility of performing simultaneous PET and MRI studies in adult rats and mice using the same PET insert in a small-bore 9.4 T MRI.

Maramraju, S.H.; Schlyer, D.; Maramraju, S.H.; Smith, S.D.; Junnarkar, S.S.; Schulz, D.; Stoll, S.; Ravindranath, B.; Purschke, M.L.; Rescia, S.; Southekal, S.; Pratte, J.-F.; Vaska, P.; Woody, C.L.; Schlyer, D.J.

2011-03-25T23:59:59.000Z

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

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

114

High-Resolution fMRI Maps of Cortical Activation in Nonhuman Primates: Correlation with Intrinsic Signal Optical Images  

E-Print Network [OSTI]

, without benefit of contrast agents, at a magnetic field strength of 9.4 tesla, BOLD fMRI can reveal these regions participate in sensation, motor response, attention, memory, cognition, and emotion. BOLD f

Roe, Anna Wang

115

Technical Note Intracoronary MR Imaging Using a 0.014-Inch MR  

E-Print Network [OSTI]

-Guided Coronary Interventions Bensheng Qiu, PhD,1,2 Fabao Gao, MD, PhD,1,3 Parag Karmarkar, MS,1 Ergin Atalar, Ph, thus, generate intracoronary MR imaging with balloon in- flation. Key Words: MRI; coronary intervention; MR imaging guidewire; percutaneous transluminal coronary angio- plasty (PTCA) J. Magn. Reson. Imaging

Atalar, Ergin

116

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

117

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

118

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

SciTech Connect (OSTI)

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

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

1994-12-01T23:59:59.000Z

119

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.

120

Controlled-Resonant Surface Tapping-Mode Scanning Probe Electrospray Ionization Mass Spectrometry Imaging  

SciTech Connect (OSTI)

This paper reports on the advancement of a controlled-resonance surface tapping-mode single capillary liquid junction extraction/ESI emitter for mass spectrometry imaging. The basic instrumental setup and the general operation of the system were discussed and optimized performance metrics were presented. The ability to spot sample, lane scan and chemically image in an automated and controlled fashion were demonstrated. Rapid, automated spot sampling was demonstrated for a variety of compound types including the cationic dye basic blue 7, the oligosaccharide cellopentaose, and the protein equine heart cytochrome c. The system was used for lane scanning and chemical imaging of the cationic dye crystal violet in inked lines on glass and for lipid distributions in mouse brain thin tissue sections. Imaging of the lipids in mouse brain tissue under optimized conditions provided a spatial resolution of approximately 35 m based on the ability to distinguish between features observed both in the optical and mass spectral chemical images. The sampling spatial resolution of this system was comparable to the best resolution that has been reported for other types of atmospheric pressure liquid extraction-based surface sampling/ionization techniques used for mass spectrometry imaging.

Lorenz, Matthias [ORNL] [ORNL; Ovchinnikova, Olga S [ORNL] [ORNL; Kertesz, Vilmos [ORNL] [ORNL; Van Berkel, Gary J [ORNL] [ORNL

2014-01-01T23:59:59.000Z

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121

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

122

Resonant  

Office of Scientific and Technical Information (OSTI)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinan antagonist Journal Article: CrystalFG36-08GO18149Speeding accessProposal Title:TechnicalSmall) Resonant

123

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

124

A 200-MHz fully-differential CMOS front-end with an on-chip inductor for magnetic resonance imaging  

E-Print Network [OSTI]

A 200-MHZ FULLY-DIFFERENTIAL CMOS FRONT-END WITH AN ON-CHIP INDUCTOR FOR MAGNETIC RESONANCE IMAGING A Thesis by JULIO ENRIQUE AYALA II Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2005 Major Subject: Electrical Engineering A 200-MHZ FULLY-DIFFERENTIAL CMOS FRONT-END WITH AN ON-CHIP INDUCTOR FOR MAGNETIC RESONANCE IMAGING A Thesis by JULIO ENRIQUE AYALA II Submitted to the Office of Graduate...

Ayala, Julio Enqrique, II

2007-04-25T23:59:59.000Z

125

Saline as the Sole Contrast Agent for Successful MRI-guided Epidural Injections  

SciTech Connect (OSTI)

Purpose. To assess the performance of sterile saline solution as the sole contrast agent for percutaneous magnetic resonance imaging (MRI)-guided epidural injections at 1.5 T. Methods. A retrospective analysis of two different techniques of MRI-guided epidural injections was performed with either gadolinium-enhanced saline solution or sterile saline solution for documentation of the epidural location of the needle tip. T1-weighted spoiled gradient echo (FLASH) images or T2-weighted single-shot turbo spin echo (HASTE) images visualized the test injectants. Methods were compared by technical success rate, image quality, table time, and rate of complications. Results. 105 MRI-guided epidural injections (12 of 105 with gadolinium-enhanced saline solution and 93 of 105 with sterile saline solution) were performed successfully and without complications. Visualization of sterile saline solution and gadolinium-enhanced saline solution was sufficient, good, or excellent in all 105 interventions. For either test injectant, quantitative image analysis demonstrated comparable high contrast-to-noise ratios of test injectants to adjacent body substances with reliable statistical significance levels (p < 0.001). The mean table time was 22 {+-} 9 min in the gadolinium-enhanced saline solution group and 22 {+-} 8 min in the saline solution group (p = 0.75). Conclusion. Sterile saline is suitable as the sole contrast agent for successful and safe percutaneous MRI-guided epidural drug delivery at 1.5 T.

Deli, Martin, E-mail: martin.deli@web.de [University of Witten/Herdecke, Department of Radiology and Microtherapy, Groenemeyer Institute for Microtherapy (GIMT) (Germany); Fritz, Jan, E-mail: jfritz9@jhmi.edu [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Mateiescu, Serban, E-mail: mateiescu@microtherapy.de; Busch, Martin, E-mail: busch@microtherapy.de [University of Witten/Herdecke, Department of Radiology and Microtherapy, Groenemeyer Institute for Microtherapy (GIMT) (Germany); Carrino, John A., E-mail: jcarrin2@jhmi.edu [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Becker, Jan, E-mail: j.becker@microtherapy.de; Garmer, Marietta, E-mail: garmer@microtherapy.de; Groenemeyer, Dietrich, E-mail: dg@microtherapy.de [University of Witten/Herdecke, Department of Radiology and Microtherapy, Groenemeyer Institute for Microtherapy (GIMT) (Germany)

2013-06-15T23:59:59.000Z

126

3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data  

E-Print Network [OSTI]

3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data Yalin Wang1 , Xianfeng Gu2 , Paul algorithm finds a harmonic map from a 3-manifold to a 3D solid sphere and the second is a novel sphere of magnetic resonance images (MRI). A heat flow method is used to solve the volumetric harmonic mapping

Thompson, Paul

127

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

128

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

129

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; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

2006-10-03T23:59:59.000Z

130

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; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

2006-05-30T23:59:59.000Z

131

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 de 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; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

2005-04-26T23:59:59.000Z

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

Engineered metalloproteins as contrast sensors for molecular fMRI  

E-Print Network [OSTI]

Functional brain imaging technologies seek to expand our understanding of intact neural systems. Present day functional MRI (fMRI) measures the delayed hemodynamic response that is indirectly associated with neural activity. ...

Lelyveld, Victor S

2010-01-01T23:59:59.000Z

135

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

136

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

137

NMR and MRI apparatus and method  

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. Additional signal to noise benefits are obtained by use of a low noise polarization coil, comprising litz wire or superconducting materials. 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; Kelso, Nathan; Lee, SeungKyun; Moessle, Michael; Myers, Whittier; McDermott, Robert; ten Haken, Bernard; Pines, Alexander; Trabesinger, Andreas

2007-03-06T23:59:59.000Z

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

Pulmonary Hemorrhage: Imaging with a New Magnetic Resonance Blood Pool Agent in Conjunction with Breathheld Three-Dimensional Magnetic Resonance Angiography  

SciTech Connect (OSTI)

Purpose: To describe the three-dimensional magnetic resonance angiography (3D MRA) imaging appearance of the pulmonary arteries following administration of a superparamagnetic iron oxide blood pool agent to human volunteers, and to demonstrate in an animal model (pigs) how this technique can be used to detect pulmonary parenchymal hemorrhage. Methods: Two volunteers were examined following the intravenous administration of a superparamagnetic iron oxide blood pool agent (NC100150 Injection, Nycomed Amersham Imaging, Wayne, PA, USA). T1-weighted 3D gradient recalled echo (GRE) image sets (TR/TE 5.1/1.4 msec, flip angle 30 deg.) were acquired breathheld over 24 sec. To assess the detectability of pulmonary bleeding with intravascular MR contrast, pulmonary parenchymal injuries were created in two animals under general anesthesia, and fast T1-weighted 3D GRE image sets collected before and after the injury. Results: Administration of the intravascular contrast in the two volunteers resulted in selective enhancement of the pulmonary vasculature permitting complete visualization and excellent delineation of central, segmental, and subsegmental arteries. Following iatrogenic injury in the two animals, pulmonary hemorrhage was readily detected on the 3D image sets. Conclusion: The data presented illustrate that ultrafast 3D GRE MR imaging in conjunction with an intravenously administered intravascular blood pool agent can be used to perform high-quality pulmonary MRA as well as to detect pulmonary hemorrhage.

Weishaupt, Dominik; Hilfiker, Paul R.; Schmidt, Michaela; Debatin, Joerg F. [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland)

1999-07-15T23:59:59.000Z

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

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

142

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

SciTech Connect (OSTI)

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

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

2011-07-01T23:59:59.000Z

143

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

144

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

145

Advanced slow-magic angle spinning probe for magnetic resonance imaging and spectroscopy  

DOE Patents [OSTI]

The present invention relates to a probe and processes useful for magnetic resonance imaging and spectroscopy instruments. More particularly, the invention relates to a MR probe and processes for obtaining resolution enhancements of fluid objects, including live specimens, using an ultra-slow (magic angle) spinning (MAS) of the specimen combined with a modified phase-corrected magic angle turning (PHORMAT) pulse sequence. Proton NMR spectra were measured of the torso and the top part of the belly of a female BALBc mouse in a 2T field, while spinning the animal at a speed of 1.5 Hz. Results show that even in this relatively low field with PHORMAT, an isotropic spectrum is obtained with line widths that are a factor 4.6 smaller than those obtained in a stationary mouse. Resolution of 1H NMR metabolite spectra are thus significantly enhanced. Results indicate that PHORMAT has the potential to significantly increase the utility of 1H NMR spectroscopy for in vivo biochemical, biomedical and/or medical applications involving large-sized biological objects such as mice, rats and even humans within a hospital setting. For small-sized objects, including biological objects, such as excised tissues, organs, live bacterial cells, and biofilms, use of PASS at a spinning rate of 30 Hz and above is preferred.

Wind, Robert A.; Hu, Jian Zhi; Minard, Kevin R.; Rommereim, Donald N.

2006-01-24T23:59:59.000Z

146

MR-Guided Freehand Biopsy of Liver Lesions With Fast Continuous Imaging Using a 1.0-T Open MRI Scanner: Experience in 50 Patients  

SciTech Connect (OSTI)

The purpose of this study was to assess a new open system with a field-strength of 1.0 T for the feasibility of liver biopsy using the freehand technique with fast continuous imaging. Fifty patients with focal liver lesions measuring 5 to 30 mm in diameter were included in the study. Guidance and monitoring was performed using a 1.0-T open magnetic resonance (MR) scanner (Panorama HFO; Philips Healthcare, Best, The Netherlands). With fast continuous imaging using a T1-weighted (T1W) gradient echo (GRE) sequence after administration of gadolinium (Gd)-EOB-DTPA, the needle was placed into the lesion. An interface for interactive dynamic viewing in two perpendicular planes prevented needle deviations T2-weighted turbo spin echo (TSE) fat-suppressed sequence was added to rule out postinterventional hematoma or biloma. All lesions were visible on the interventional images. Biopsy was technically successful, and solid specimens were obtained in all cases. Forty-six patients showed a histopathologic pattern other than native liver tissue, thus confirming correct position of the needle. Time between determination of the lesion and performance of the control scan was on average 18 min. No major complications were recorded. MR guidance with the new 1-T open system must be considered an attractive alternative for liver punction. An interface for dynamic imaging of needle guidance and T1W-GRE imaging with administration of Gd-EOB-DTPA for contrast enhancement allows the pinpoint puncture of liver lesions.

Fischbach, Frank, E-mail: frank.fischbach@med.ovgu.de [Otto von Guericke University, Department of Radiology, Medical School (Germany); Bunke, Juergen [Philips Healthcare (Germany); Thormann, Markus; Gaffke, Gunnar; Jungnickel, Kerstin [Otto von Guericke University, Department of Radiology, Medical School (Germany); Smink, Jouke [Philips Healthcare (Germany); Ricke, Jens [Otto von Guericke University, Department of Radiology, Medical School (Germany)

2011-02-15T23:59:59.000Z

147

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.

148

A 64-channel personal computer based image reconstruction system and applications in single echo acquisition magnetic resonance elastography and ultra-fast magnetic resonance imaging.  

E-Print Network [OSTI]

, this value is 2? x 42.5759 MHz/Tesla. This translates to a Larmor frequency of 200.238 MHz for the 4.7T magnet situated in the Magnetic Resonance Systems Lab (MRSL). In the presence of the static ????the proton population aligns itself according...

Yallapragada, Naresh

2009-05-15T23:59:59.000Z

149

NMR/MRI with hyperpolarized gas and high Tc SQUID  

DOE Patents [OSTI]

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

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

2000-01-01T23:59:59.000Z

150

Analysis, design, and application of circularly polarized RF receiver antennas for magnetic resonance imaging  

E-Print Network [OSTI]

, an example coil will be designed for significantly improved SNR over the spine, with a minimum of added cost and complexity. The receiver antenna will be evaluated in both lab and clinical environments, with the results presented in this thesis. Further MRI...

Usey, Michael Christopher

1995-01-01T23:59:59.000Z

151

Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources  

E-Print Network [OSTI]

in units of radians/tesla and B is the magnetic flux density of the applied field, expressed in units of tesla. The hydrogen nucleus, which consists of a single proton, is the most abundantly present in tissue and is most widely used for MRI...

Kurpad, Krishna Nagaraj

2005-11-01T23:59:59.000Z

152

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

153

MRI Investigations of Particle Motion within a Three-Dimensional Vibro-Fluidized Granular Bed  

E-Print Network [OSTI]

The unique ability of magnetic resonance imaging (MRI) to provide spatial and temporal information from optically opaque systems, in three dimensions, make it an ideal tool to study the internal motion of rapid granular flows. This paper will focus on the use of ultra-fast velocity compensated MRI measurements to study particle velocity and density distributions in a granular gas, produced by vibrating vertically a bed of mustard seeds at 40 Hz. Specifically, a velocity compensated, double spin-echo, triggered, one-dimensional MRI profiling pulse sequence was developed. This gives an MRI temporal resolution of approximately 2 ms and also minimises MRI velocity artefacts. 12 phase measurements per vibration cycle were used. The data can be used to extract values of the mustard seed average velocity and velocity propagators (probability distributions functions) as a function of the phase of the vibration cycle and vertical height within the cell. The data show strong transient effects during the impact phase of the vibration. A detailed discussion of the temporal passage of the individual phase resolved, height resolved velocity distributions, along with seed velocity propagators at a fix height from the vibrating base is presented.

Mick D. Mantle; Andrew J. Sederman; Lynn F. Gladden; Jonathan M. Huntley; Tom W. Martin Ricky D. Wildman; Mark D. Shattuck

2007-02-08T23:59:59.000Z

154

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

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

Developing novel polymer architectures for applications In magnetic resonance imaging and self-assembly  

E-Print Network [OSTI]

Macromolecular scaffolds for drug delivery, self-assembly, and imaging applications have attracted significant attention over the last several decades. As polymerization techniques become more sophisticated, it becomes ...

McCombs, Jessica R. (Jessica Rose)

2013-01-01T23:59:59.000Z

158

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

159

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

E-Print Network [OSTI]

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

Thompson, Paul

160

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

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

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

DOE Patents [OSTI]

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

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

1990-01-01T23:59:59.000Z

162

FRPRCS-8 University of Patras, Patras, Greece, July 16-18, 2007 MAGNETIC RESONANCE IMAGING OF CONCRETE WITH FRP  

E-Print Network [OSTI]

on the amount of water present but also on its mobility. Water in porous media is generally characterised. Nevertheless, the water in some porous matrices does have sufficiently long relaxation times for MRI to be able (MRI) to measure water content in a range of porous media including rocks [6,7,8,9], soils [10

Burgoyne, Chris

163

Clinical Evaluation of Stereotactic Target Localization Using 3-Tesla MRI for Radiosurgery Planning  

SciTech Connect (OSTI)

Purpose: Increasing the magnetic resonance imaging (MRI) field strength can improve image resolution and quality, but concerns remain regarding the influence on geometric fidelity. The objectives of the present study were to spatially investigate the effect of 3-Tesla (3T) MRI on clinical target localization for stereotactic radiosurgery. Methods and Materials: A total of 39 patients were enrolled in a research ethics board-approved prospective clinical trial. Imaging (1.5T and 3T MRI and computed tomography) was performed after stereotactic frame placement. Stereotactic target localization at 1.5T vs. 3T was retrospectively analyzed in a representative cohort of patients with tumor (n = 4) and functional (n = 5) radiosurgical targets. The spatial congruency of the tumor gross target volumes was determined by the mean discrepancy between the average gross target volume surfaces at 1.5T and 3T. Reproducibility was assessed by the displacement from an averaged surface and volume congruency. Spatial congruency and the reproducibility of functional radiosurgical targets was determined by comparing the mean and standard deviation of the isocenter coordinates. Results: Overall, the mean absolute discrepancy across all patients was 0.67 mm (95% confidence interval, 0.51-0.83), significantly <1 mm (p < .010). No differences were found in the overall interuser target volume congruence (mean, 84% for 1.5T vs. 84% for 3T, p > .4), and the gross target volume surface mean displacements were similar within and between users. The overall average isocenter coordinate discrepancy for the functional targets at 1.5T and 3T was 0.33 mm (95% confidence interval, 0.20-0.48), with no patient-specific differences between the mean values (p >.2) or standard deviations (p >.1). Conclusion: Our results have provided clinically relevant evidence supporting the spatial validity of 3T MRI for use in stereotactic radiosurgery under the imaging conditions used.

MacFadden, Derek [University of Toronto Faculty of Medicine, Toronto, ON (Canada); Zhang Beibei; Brock, Kristy K. [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, ON (Canada); Hodaie, Mojgan [Division of Neurosurgery, Toronto Western Hospital, Toronto, ON (Canada); Laperriere, Normand [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); Schwartz, Michael [Division of Neurosurgery, Toronto Western Hospital, Toronto, ON (Canada); Tsao, May [Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); Department of Radiation Oncology, Sunnybrook Regional Cancer Centre, Toronto, ON (Canada); Stainsby, Jeffrey [Applied Science Laboratories, GE Healthcare, Mississauga, ON (Canada); Lockwood, Gina [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, ON (Canada); Mikulis, David [Department of Medical Imaging, University Health Network, Toronto, ON (Canada); Menard, Cynthia, E-mail: cynthia.menard@rmp.uhn.on.c [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada)

2010-04-15T23:59:59.000Z

164

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

165

Adjustable permanent magnet assembly for NMR and MRI  

DOE Patents [OSTI]

System and methods for designing and using single-sided magnet assemblies for magnetic resonance imaging (MRI) are disclosed. The single-sided magnet assemblies can include an array of permanent magnets disposed at selected positions. At least one of the permanent magnets can be configured to rotate about an axis of rotation in the range of at least +/-10 degrees and can include a magnetization having a vector component perpendicular to the axis of rotation. The single-sided magnet assemblies can further include a magnet frame that is configured to hold the permanent magnets in place while allowing the at least one of the permanent magnets to rotate about the axis of rotation.

Pines, Alexander; Paulsen, Jeffrey; Bouchard, Louis S; Blumich, Bernhard

2013-10-29T23:59:59.000Z

166

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

167

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

168

Assessment of Wall Shear Stress Changes in Arteries and Veins of Arteriovenous Polytetrafluoroethylene Grafts Using Magnetic Resonance Imaging  

SciTech Connect (OSTI)

The purpose of the study was to determine simultaneously the temporal changes in luminal vessel area, blood flow, and wall shear stress (WSS) in both the anastomosed artery (AA) and vein (AV) of arteriovenous polytetrafluoroethylene (PTFE) grafts. PTFE grafts were placed from the iliac artery to the ipsilateral iliac vein in 12 castrated juvenile male pigs. Contrast-enhanced magnetic resonance angiograpgy with cine phase-contrast magnetic resonance imaging was performed. Luminal vessel area, blood flow, and WSS in the aorta, AA, AV, and inferior vena cava were determined at 3 days (D3), 7 days (D7), and 14 days (D14) after graft placement. Elastin von Gieson staining of the AV was performed. The average WSS of the AA was highest at D3 and then decreased by D7 and D14. In contrast, the average WSS and intima-to-media ratio of the AV increased from D3 to D7 and peaked by D14. Similarly, the average area of the AA was highest by D7 and began to approximate the control artery by D14. The average area of the AV had decreased to its lowest by D7. High blood flows through the AA causes a decrease in average WSS and increase in the average luminal vessel area, whereas at the AV, the average WSS and intima-to-media ratio both increase while the average luminal vessel area decreases.

Misra, Sanjay, E-mail: Misra.sanjay@mayo.edu; Woodrum, David A. [Mayo Clinic, Department of Radiology (United States); Homburger, Jay [Medical College of Georgia, Department of Vascular Surgery (United States); Elkouri, Stephane [Centre Hospitalier de I'Universite de Montreal, Department of Vascular Surgery (Canada); Mandrekar, Jayawant N. [Mayo Clinic, Division of Biostatistics (United States); Barocas, Victor [University of Minnesota, Department of Biomedical Engineering (United States); Glockner, James F. [Mayo Clinic, Department of Radiology (United States); Rajan, Dheeraj K. [Toronto General Hospital, University Health Network, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada); Mukhopadhyay, Debabrata [Mayo Clinic, Department of Biochemistry and Molecular Biology (United States)

2006-08-15T23:59:59.000Z

169

Nanoscale NMR Spectroscopy and Imaging of Multiple Nuclear Species  

E-Print Network [OSTI]

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are well-established techniques that provide valuable information in a diverse set of disciplines but are currently limited to macroscopic sample volumes. Here we demonstrate nanoscale NMR spectroscopy and imaging under ambient conditions of samples containing multiple nuclear species, using nitrogen-vacancy (NV) colour centres in diamond as sensors. With single, shallow NV centres in a diamond chip and samples placed on the diamond surface, we perform NMR spectroscopy and one-dimensional MRI on few-nanometre-sized samples containing $^1$H and $^{19}$F nuclei. Alternatively, we employ a high-density NV layer near the surface of a diamond chip to demonstrate wide-field optical NMR spectroscopy of nanoscale samples containing $^1$H, $^{19}$F, and $^{31}$P nuclei, as well as multi-species two-dimensional optical MRI with sub-micron resolution. For all diamond samples exposed to air, we identify a ubiquitous $^1$H NMR signal, consistent with a $\\sim 1$ nm layer of adsorbed hydrocarbons or water on the diamond surface and below any sample placed on the diamond. This work lays the foundation for nanoscale NMR and MRI applications such as studies of single proteins and functional biological imaging with subcellular resolution, as well as characterization of thin films with sub-nanometre resolution.

Stephen J. DeVience; Linh M. Pham; Igor Lovchinsky; Alexander O. Sushkov; Nir Bar-Gill; Chinmay Belthangady; Francesco Casola; Madeleine Corbett; Huiliang Zhang; Mikhail Lukin; Hongkun Park; Amir Yacoby; Ronald L. Walsworth

2014-06-12T23:59:59.000Z

170

Prediction of the reversibility of the ultrasound-induced blood-brain barrier opening using passive cavitation detection with magnetic resonance imaging  

E-Print Network [OSTI]

cavitation detection with magnetic resonance imaging validation Tao Sun1 , Gesthimani Samiotaki1 and Elisa E (diameters: 1-2, 4-5, or 6-8 m). A 10-MHz passive cavitation detector was used to acquire cavitation signals that the stable cavitation dose increased with the number of days required for closing while it reached a plateau

Konofagou, Elisa E.

171

HIGH RESOLUTION, MRI-BASED, SEGMENTED, COMPUTERIZED HEAD PHANTOM.  

E-Print Network [OSTI]

was created from 124 transverse MRI images of a healthy normal. The transverse T2 slices, recorded in a 256x. Internal volumes compare favorably to those described in the ICRP Reference Man. Conclusion and improved. We have developed a voxel based head phantom by manually drawing contours on 124 transverse MRI

Duncan, James S.

172

Classification of brain compartments and head injury lesions by neural networks applied to magnetic resonance images  

E-Print Network [OSTI]

the limitation that they carry no infor- mation regarding the relative position of pixels with respect to each other [14] . The gray-level co-occurrence matrices (GLCM) method is a "direct approach" to texture analysis using low-level features of the image... by matrices [20]. The transformation matrices are based on the training samples and then applied to the testing samples. Given an original feature vector, x, and an f x f transformation matrix, A, the transformed vector, y, is given by [20]: ~A. E, (13...

Kischell, Eric Robert

1993-01-01T23:59:59.000Z

173

Evaluation of potential internal target volume of liver tumors using cine-MRI  

SciTech Connect (OSTI)

Purpose: Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. Methods: The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas–Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV {sub Potential}). The concordance between ITV {sub Potential} and ITV estimated with 4DCT (ITV {sub 4DCT}) was evaluated using the Dice’s similarity coefficient (DSC). Results: The distance between blood vessel positions determined with motion tracking and manual detection was analyzed. The mean and SD of the distance were less than 0.80 and 0.52 mm, respectively. The maximum ranges of tumor motion on cine-MRI were 2.4 ± 1.4 mm (range, 1.0–5.0 mm), 4.4 ± 3.3 mm (range, 0.8–9.4 mm), and 14.7 ± 5.9 mm (range, 7.4–23.4 mm) in lateral, anterior–posterior, and superior–inferior directions, respectively. The ranges in the superior–inferior direction were larger than those estimated with 4DCT images for all patients. The volume of ITV {sub Potential} was 160.3% ± 13.5% (range, 142.0%–179.2%) of the ITV {sub 4DCT}. The maximum DSC values were observed when the cutoff value of 24.7% ± 4.0% (range, 20%–29%) was applied. Conclusions: The authors demonstrated a novel method of calculating 3D motion and ITV {sub Potential} of liver cancer using orthogonal cine-MRI. Their method achieved accurate calculation of the respiratory motion of moving structures. Individual evaluation of the ITV {sub Potential} will aid in improving respiration management and treatment planning.

Akino, Yuichi, E-mail: akino@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 5650871, Japan and Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan); Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko [Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan)

2014-11-01T23:59:59.000Z

174

REVIEW ARTICLE Multimodal MRI of Experimental Stroke  

E-Print Network [OSTI]

REVIEW ARTICLE Multimodal MRI of Experimental Stroke Timothy Q. Duong Received: 30 October 2011+Business Media, LLC 2011 Abstract Stroke is the fourth leading cause of death and the leading cause of long-term disability in USA. Brain imaging data from experimental stroke models and stroke patients have shown

Duong, Timothy Q.

175

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.

176

High spatial resolution brain functional MRI using submillimeter balanced steady-state free precession acquisition  

SciTech Connect (OSTI)

Purpose: One of the technical advantages of functional magnetic resonance imaging (fMRI) is its precise localization of changes from neuronal activities. While current practice of fMRI acquisition at voxel size around 3 × 3 × 3 mm{sup 3} achieves satisfactory results in studies of basic brain functions, higher spatial resolution is required in order to resolve finer cortical structures. This study investigated spatial resolution effects on brain fMRI experiments using balanced steady-state free precession (bSSFP) imaging with 0.37 mm{sup 3} voxel volume at 3.0 T. Methods: In fMRI experiments, full and unilateral visual field 5 Hz flashing checkerboard stimulations were given to healthy subjects. The bSSFP imaging experiments were performed at three different frequency offsets to widen the coverage, with functional activations in the primary visual cortex analyzed using the general linear model. Variations of the spatial resolution were achieved by removing outerk-space data components. Results: Results show that a reduction in voxel volume from 3.44 × 3.44 × 2 mm{sup 3} to 0.43 × 0.43 × 2 mm{sup 3} has resulted in an increase of the functional activation signals from (7.7 ± 1.7)% to (20.9 ± 2.0)% at 3.0 T, despite of the threefold SNR decreases in the original images, leading to nearly invariant functional contrast-to-noise ratios (fCNR) even at high spatial resolution. Activation signals aligning nicely with gray matter sulci at high spatial resolution would, on the other hand, have possibly been mistaken as noise at low spatial resolution. Conclusions: It is concluded that the bSSFP sequence is a plausible technique for fMRI investigations at submillimeter voxel widths without compromising fCNR. The reduction of partial volume averaging with nonactivated brain tissues to retain fCNR is uniquely suitable for high spatial resolution applications such as the resolving of columnar organization in the brain.

Wu, Pei-Hsin; Chung, Hsiao-Wen [Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)] [Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Tsai, Ping-Huei [Imaging Research Center, Taipei Medical University, Taipei 11031, Taiwan and Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei 11031, Taiwan (China)] [Imaging Research Center, Taipei Medical University, Taipei 11031, Taiwan and Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei 11031, Taiwan (China); Wu, Ming-Long, E-mail: minglong.wu@csie.ncku.edu.tw [Institute of Medical Informatics, National Cheng-Kung University, Tainan 70101, Taiwan and Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)] [Institute of Medical Informatics, National Cheng-Kung University, Tainan 70101, Taiwan and Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China); Chuang, Tzu-Chao [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China)] [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Shih, Yi-Yu [Siemens Limited Healthcare Sector, Taipei 11503, Taiwan (China)] [Siemens Limited Healthcare Sector, Taipei 11503, Taiwan (China); Huang, Teng-Yi [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)] [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

2013-12-15T23:59:59.000Z

177

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

178

Neuroimaging at 1.5 T and 3.0 T: Comparison of Oxygenation-Sensitive Magnetic Resonance Imaging  

E-Print Network [OSTI]

and becomes a larger fraction of the total noise at 3.0 T. Activation of the primary motor and visual cortex a magnetic field strength of 1.5 Tesla (T) seems to represent a good compromise. Functional MRI (f

Glover, Gary H.

179

Robust inference of baseline optical properties of the human head with 3D segmentation from magnetic resonance imaging  

E-Print Network [OSTI]

and voltage-sensitive dyes [4]. By relying on photon transport through tis- sue, DOT also accesses spatial, measuring both total hemoglobin concentration and oxygenation. Optical con- trast can also arise from cellMRI). In addition to sensitivity to ab- sorbing chromophores, DOT can be sensitive to cellular scattering changes

Barnett, Alex

180

The magnetic resonance force microscope: A new microscopic probe of magnetic materials  

SciTech Connect (OSTI)

The magnetic resonance force microscope (MRFM) marries the techniques of magnetic resonance imaging (MRI) and atomic force microscopy (AFM), to produce a three-dimensional imaging instrument with high, potentially atomic-scale, resolution. The principle of the MRFM has been successfully demonstrated in numerous experiments. By virtue of its unique capabilities the MRFM shows promise to make important contributions in fields ranging from three-dimensional materials characterization to bio-molecular structure determination. Here the authors focus on its application to the characterization and study of layered magnetic materials; the ability to illuminate the properties of buried interfaces in such materials is a particularly important goal. While sensitivity and spatial resolution are currently still far from their theoretical limits, they are nonetheless comparable to or superior to that achievable in conventional MRI. Further improvement of the MRFM will involve operation at lower temperature, application of larger field gradients, introduction of advanced mechanical resonators and improved reduction of the spurious coupling when the magnet is on the resonator.

Hammel, P.C.; Zhang, Z. [Los Alamos National Lab., NM (United States); Midzor, M.; Roukes, M.L. [California Inst. of Tech., Pasadena, CA (United States); Wigen, P.E. [Ohio State Univ., Columbus, OH (United States); Childress, J.R. [Univ. of Florida, Gainesville, FL (United States)

1997-08-06T23:59:59.000Z

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


181

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

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

NMR, MRI, and spectroscopic MRI in inhomogeneous fields  

DOE Patents [OSTI]

A method for locally creating effectively homogeneous or "clean" magnetic field gradients (of high uniformity) for imaging (with NMR, MRI, or spectroscopic MRI) both in in-situ and ex-situ systems with high degrees of inhomogeneous field strength. THe method of imaging comprises: a) providing a functional approximation of an inhomogeneous static magnetic field strength B.sub.0({right arrow over (r)}) at a spatial position {right arrow over (r)}; b) providing a temporal functional approximation of {right arrow over (G)}.sub.shim(t) with i basis functions and j variables for each basis function, resulting in v.sub.ij variables; c) providing a measured value .OMEGA., which is an temporally accumulated dephasing due to the inhomogeneities of B.sub.0({right arrow over(r)}); and d) minimizing a difference in the local dephasing angle .phi.({right arrow over (r)},t)=.gamma..intg..sub.0.sup.t{square root over (|{right arrow over (B)}.sub.1({right arrow over (r)},t')|.sup.2+({right arrow over (r)}{right arrow over (G)}.sub.shimG.sub.shim(t')+.parallel.{right arrow over (B)}.sub.0({right arrow over (r)}).parallel..DELTA..omega.({right arrow over (r)},t'/.gamma/).sup.2)}dt'-.OMEGA. by varying the v.sub.ij variables to form a set of minimized v.sub.ij variables. The method requires calibration of the static fields prior to minimization, but may thereafter be implemented without such calibration, may be used in open or closed systems, and potentially portable systems.

Demas, Vasiliki; Pines, Alexander; Martin, Rachel W; Franck, John; Reimer, Jeffrey A

2013-12-24T23:59:59.000Z

184

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

SciTech Connect (OSTI)

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

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

2008-10-29T23:59:59.000Z

185

Amplification of Xenon NMR and MRI by remote detection  

SciTech Connect (OSTI)

A novel technique is proposed in which a nuclear magneticresonance (NMR) spectrum or magnetic resonance image (MRI) is encoded andstored as spin polarization and is then moved to a different physicallocation to be detected. Remote detection allows the separateoptimization of the encoding and detection steps, permitting theindependent choice of experimental conditions, and excitation anddetection methodologies. In the first experimental demonstration of thistechnique, we show that NMR signal can be amplified by taking diluted129Xe from a porous sample placed inside a large encoding coil, andconcentrating it into a smaller detection coil. In general, the study ofNMR active molecules at low concentration that have low physical fillingfactor is facilitated by remote detection. In the second experiment, MRIinformation encoded in a very low field magnet (4-7mT) is transferred toa high field magnet (4.2 T) in order to be detected under optimizedconditions. Furthermore, remote detection allows the utilization ofultra-sensitive optical or superconducting detection techniques, whichbroadens the horizon of NMR experimentation.

Moule, Adam J.; Spence, Megan M.; Han, Song-I.; Seeley, JulietteA.; Pierce, Kimberly L.; Saxena, Sunil; Pines, Alexander

2003-03-31T23:59:59.000Z

186

Images of Vega Dust Ring at 350 and 450 microns: New Clues to the Trapping of Multiple-Sized Dust Particles in Planetary Resonances  

E-Print Network [OSTI]

We have used the SHARC II camera at Caltech Submillimeter Observatory to make 350 and 450 micron images of the Vega dust disk at spatial resolutions (FWHM) of 9.7" and 11.1", respectively. The images show a ring-like morphology (radius \\~ 100 AU) with inhomogeneous structure that is qualitatively different from that previously reported at 850 microns and longer wavelengths. We attribute the 350/450 micron emission to a grain population whose characteristic size (~ 1 mm) is intermediate between that of the cm-sized grains responsible for emission longward of 850 microns and the much smaller grains (< 18 microns) in the extensive halo, visible at 70 microns, discussed by Su et al. (2005). We have combined our submillimeter images with Spitzer data at 70 microns to produce 2-d maps of line-of-sight optical depth (relative column density). These "tau maps" suggest that the mm-sized grains are located preferentially in three symmetrically-located concentrations. If so, then this structure could be understood in terms of the Wyatt (2003) model in which planetesimals are trapped in the mean motion resonances of a Neptune-mass planet at 65 AU, provided allowance is made for the spatial distribution of dust grains to differ from that of the parent planetesimals. The peaks of the tau maps are, in fact, located near the expected positions corresponding to the 4:3 resonance. If this identification is confirmed by future observations, it would resolve an ambiguity with regard to the location of the planet.

K. A. Marsh; C. D. Dowell; T. Velusamy; K. Grogan; C. A. Beichman

2006-06-14T23:59:59.000Z

187

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

188

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

189

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

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

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

192

MRI Compatibility Evaluation of a Piezoelectric Actuator System for a Neural Interventional Robot  

E-Print Network [OSTI]

on a Phillips Achieva 3 Tesla MRI machine under diagnostic T1 and T2, high speed FGRE and functional EPI imaging a general-purpose robotic assistant for open MRI based upon Shinsei ultrasonic motors[7]. An investigation describes ultrasonic motor drive techniques that enhance MR-compatibility in [9]. The feasibility of using

Camesano, Terri

193

High-resolution 18F-FDG PET with MRI for monitoring response to treatment in rheumatoid arthritis  

E-Print Network [OSTI]

of a dedicated breast PET/CT scanner during human imaging. Jhigh-resolution 18 F-FDG PET images (pseudocolor) overlaidMONTH High-resolution 18 F-FDG PET with MRI for monitoring

2010-01-01T23:59:59.000Z

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

Dosimetric feasibility of real-time MRI-guided proton therapy  

SciTech Connect (OSTI)

Purpose: Magnetic resonance imaging (MRI) is a prime candidate for image-guided radiotherapy. This study was designed to assess the feasibility of real-time MRI-guided proton therapy by quantifying the dosimetric effects induced by the magnetic field in patients’ plans and identifying the associated clinical consequences. Methods: Monte Carlo dose calculation was performed for nine patients of various treatment sites (lung, liver, prostate, brain, skull-base, and spine) and tissue homogeneities, in the presence of 0.5 and 1.5 T magnetic fields. Dose volume histogram (DVH) parameters such as D{sub 95}, D{sub 5}, and V{sub 20} as well as equivalent uniform dose were compared for the target and organs at risk, before and after applying the magnetic field. The authors further assessed whether the plans affected by clinically relevant dose distortions could be corrected independent of the planning system. Results: By comparing the resulting dose distributions and analyzing the respective DVHs, it was determined that despite the observed lateral beam deflection, for magnetic fields of up to 0.5 T, neither was the target coverage jeopardized nor was the dose to the nearby organs increased in all cases except for prostate. However, for a 1.5 T magnetic field, the dose distortions were more pronounced and of clinical concern in all cases except for spine. In such circumstances, the target was severely underdosed, as indicated by a decrease in D{sub 95} of up to 41% of the prescribed dose compared to the nominal situation (no magnetic field). Sites such as liver and spine were less affected due to higher tissue homogeneity, typically smaller beam range, and the choice of beam directions. Simulations revealed that small modifications to certain plan parameters such as beam isocenter (up to 19 mm) and gantry angle (up to 10°) are sufficient to compensate for the magnetic field-induced dose disturbances. The authors’ observations indicate that the degree of required corrections strongly depends on the beam range and direction relative to the magnetic field. This method was also applicable to more heterogeneous scenarios such as skull-base tumors. Conclusions: This study confirmed the dosimetric feasibility of real-time MRI-guided proton therapy and delivering a clinically acceptable dose to patients with various tumor locations within magnetic fields of up to 1.5 T. This work could serve as a guide and encouragement for further efforts toward clinical implementation of hybrid MRI–proton gantry systems.

Moteabbed, M., E-mail: mmoteabbed@partners.org; Schuemann, J.; Paganetti, H. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)

2014-11-01T23:59:59.000Z

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

agent-enhanced mri measuring: Topics by E-print Network  

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

Thorstensen,1 M. Hofer,2 G. Sapiro,3 and H for population and longitudinal studies in brain imag- ing. Therefore, measuring cortical thickness from MRI data, and ignore the...

198

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.

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

Temperature elevation by HIFU in ex vivo porcine muscle: MRI measurement and simulation study  

SciTech Connect (OSTI)

Purpose: High-intensity focused ultrasound is a rapidly developing medical technology with a large number of potential clinical applications. Computational model can play a pivotal role in the planning and optimization of the treatment based on the patient's image. Nonlinear propagation effects can significantly affect the temperature elevation and should be taken into account. In order to investigate the importance of nonlinear propagation effects, nonlinear Westervelt equation was solved. Weak nonlinear propagation effects were studied. The purpose of this study was to investigate the correlation between the predicted and measured temperature elevations and lesion in a porcine muscle. Methods: The investigated single-element transducer has a focal length of 12 cm, an aperture of 8 cm, and frequency of 1.08 MHz. Porcine muscle was heated for 30 s by focused ultrasound transducer with an acoustic power in the range of 24–56 W. The theoretical model consists of nonlinear Westervelt equation with relaxation effects being taken into account and Pennes bioheat equation. Results: Excellent agreement between the measured and simulated temperature rises was found. For peak temperatures above 85–90?°C “preboiling” or cavitation activity appears and lesion distortion starts, causing small discrepancy between the measured and simulated temperature rises. From the measurements and simulations, it was shown that distortion of the lesion was caused by the “preboiling” activity. Conclusions: The present study demonstrated that for peak temperatures below 85–90?°C numerical simulation results are in excellent agreement with the experimental data in three dimensions. Both temperature rise and lesion size can be well predicted. Due to nonlinear effect the temperature in the focal region can be increased compared with the linear case. The current magnetic resonance imaging (MRI) resolution is not sufficient. Due to the inevitable averaging the measured temperature can be 10–30?°C lower than the peak temperature. Computational fluid dynamics can provide additional important information that is lost using a state of the art MRI device.

Solovchuk, Maxim A., E-mail: solovchuk@gmail.com [Center for Advanced Study in Theoretical Sciences (CASTS), National Taiwan University, Taipei 10617, Taiwan (China); Hwang, San Chao; Chang, Hsu [Medical Engineering Research Division, National Health Research Institute, Miaoli 35053, Taiwan (China)] [Medical Engineering Research Division, National Health Research Institute, Miaoli 35053, Taiwan (China); Thiriet, Marc [Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France)] [Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Sheu, Tony W. H., E-mail: twhsheu@ntu.edu.tw [Department of Engineering Science and Ocean Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, Republic of China and Center for Advanced Study in Theoretical Sciences (CASTS), National Taiwan University, Taipei 10617, Taiwan (China)] [Department of Engineering Science and Ocean Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, Republic of China and Center for Advanced Study in Theoretical Sciences (CASTS), National Taiwan University, Taipei 10617, Taiwan (China)

2014-05-15T23:59:59.000Z

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.


201

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

SciTech Connect (OSTI)

Purpose: To investigate whether 3-T esla (3T) multiparametric endorectal MRI (erMRI) can add information to established predictors regarding occult extraprostatic or high-grade prostate cancer (PC) in men with clinically localized PC. Methods and Materials: At a single academic medical center, this retrospective study's cohort included 118 men with clinically localized PC who underwent 3T multiparametric erMRI followed by radical prostatectomy, from 2008 to 2011. Multivariable logistic regression analyses in all men and in 100 with favorable-risk PC addressed whether erMRI evidence of T3 disease was associated with prostatectomy T3 or Gleason score (GS) 8-10 (in patients with biopsy GS {<=}7) PC, adjusting for age, prostate-specific antigen level, clinical T category, biopsy GS, and percent positive biopsies. Results: The accuracy of erMRI prediction of extracapsular extension and seminal vesicle invasion was 75% and 95%, respectively. For all men, erMRI evidence of a T3 lesion versus T2 was associated with an increased odds of having pT3 disease (adjusted odds ratio [AOR] 4.81, 95% confidence interval [CI] 1.36-16.98, P=.015) and pGS 8-10 (AOR 5.56, 95% CI 1.10-28.18, P=.038). In the favorable-risk population, these results were AOR 4.14 (95% CI 1.03-16.56), P=.045 and AOR 7.71 (95% CI 1.36-43.62), P=.021, respectively. Conclusions: Three-Tesla multiparametric erMRI in men with favorable-risk PC provides information beyond that contained in known preoperative predictors about the presence of occult extraprostatic and/or high-grade PC. If validated in additional studies, this information can be used to counsel men planning to undergo radical prostatectomy or radiation therapy about the possible need for adjuvant radiation therapy or the utility of adding hormone therapy, respectively.

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

2013-02-01T23:59:59.000Z

202

Use of T2-weighted magnetic resonance imaging of the optic nerve sheath to detect raised intracranial pressure  

E-Print Network [OSTI]

is accurate at measuring ONSD [27,28] and has been proposed to detect raised ICP in idiopathic hydrocephalus and to diagnose shunt malfunction [12,14,29,30]. On T2-weighted sequences, water (and CSF) exhibits a high signal (white). Fat and grey matter appear... as light grey, and white matter as dark grey. The perioptic CSF is surrounded by orbital fat. Contrast between CSF and orbital fat can be improved with fat suppression, increasing the image resolution for the ONSD measurement [12,13]. We have con- firmed...

Geeraerts, Thomas; Newcombe, Virginia F J; Coles, Jonathan P; Abate, Maria Giulia; Perkes, Iain E; Hutchinson, Peter J A; Outtrim, Jo G; Chatfield, Dot A; Menon, David K

2008-09-11T23:59:59.000Z

203

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

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

Imaging  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area.Portaldefault Sign In About |Imaging Imaging Print

206

Co-Funding for the Conference on Magnetic Resonance in Biological Systems  

SciTech Connect (OSTI)

The XXIst International Conference on Magnetic Resonance in Biological Systems (ICMRBS 2005), '60th anniversary of the discovery of Nuclear Magnetic Resonance,' was held between 16 and 21 January 2005 in Hyderabad, India. The meeting focused on a broad range of magnetic resonance methods as applied to studies of biological processes related to human health. The biennial ICMRBS has become the major venue for discussion of advances in nuclear and electron magnetic resonance (NMR & EMR/EPR) studies of the structure, dynamics, and chemical properties of important classes of biomolecules. Magnetic resonance has become an established tool in structural biology, and its special importance derives from its ability to provide atomic level information. It is becoming increasingly evident that the dynamic features of biomolecules, their intermolecular interactions, and accessible conformations in solution are data of key importance in understanding molecular recognition and function. NMR, which is already contributing to approximately 25% of the new structures being deposited with the Protein Data Bank, is destined to be a major player in the post genomic structure age with its emphasis on structure and function. In-vivo magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) results shed light on human metabolic processes and on the cellular ramifications of cancer, stroke, cardiovascular disease, and other pathologies. New methodologies in metabonomics may lead to development of new drugs and medical diagnosis. The ICMRBS is the one conference that brings together experts from high-resolution NMR, solid state NMR, EPR, in-vivo MRS and MRI, and developers of instrumentation, techniques, software, and databases. Symposia at this ICMRBS are designed to continue the fruitful cross-fertilization of ideas that has been so successful in driving the spectacular advances in this field. ICMRBS 2005 maintained the traditional format of poster sessions, and plenary lectures that highlight major advances in each of the major areas, and three parallel symposia that focused on particular biological systems, interfacial applications of magnetic resonance, and rapidly advancing technology. Funds provided partial travel support for 33 younger scientists from the U.S. (graduate students, postdoctoral research associates, and beginning faculty), selected from those who submitted accepted posters; 12 of these were invited to contribute oral presentations. Those receiving travel support were selected by a committee composed of the U.S. members of the International Advisory Committee for the meeting. Particular emphasis was placed on facilitating participation of minority and women scientists.

Alan McLaughlin, Ph.D., Director, Division of Applied Science & Technology, NIBIB, NIH

2008-10-01T23:59:59.000Z

207

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

208

A Framework for Integrating real-time MRI with Robot Control: Application to Simulated  

E-Print Network [OSTI]

1 A Framework for Integrating real-time MRI with Robot Control: Application to Simulated applications in urology [2], cardiac ablation with fluoroscopy guided Sensei robotic catheter system (Hansen interventional paradigms including image-guided robot assistance. Most often the use of an intraoperative imaging

Azevedo, Ricardo

209

Imaging  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2MLLCBasicsScience atIanIgorIlyaBuildingImaging Print

210

Imaging  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2MLLCBasicsScience atIanIgorIlyaBuildingImaging

211

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...

212

Magnetic Resonance Imaging of concrete  

E-Print Network [OSTI]

velocity · Relates Elastic modulus to speed of sound Assumes Concrete heterogeneous Can be affected by steel Modulus related to speed of sound Strength of concrete related to modulus Location of flaws structure · In both cases procedure is destructive Systems to monitor concrete modulus · Ultra-sonic pulse

Burgoyne, Chris

213

University of Vermont Center for Biomedical Imaging  

SciTech Connect (OSTI)

This grant was awarded in support of Phase 2 of the University of Vermont Center for Biomedical Imaging. Phase 2 outlined several specific aims including: The development of expertise in MRI and fMRI imaging and their applications The acquisition of peer reviewed extramural funding in support of the Center The development of a Core Imaging Advisory Board, fee structure and protocol review and approval process.

Bernstein, Dr. Ira [University of Vermont and State Agricultural College

2013-08-02T23:59:59.000Z

214

Correlated Biofilm Imaging, Transport and Metabolism Measurements...  

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

Biofilm Imaging, Transport and Metabolism Measurements via Combined Nuclear Magnetic Resonance and Confocal Correlated Biofilm Imaging, Transport and Metabolism Measurements via...

215

An anthropomorphic multimodality (CT/MRI) phantom prototype for end-to-end tests in radiation therapy  

E-Print Network [OSTI]

With the increasing complexity of external beam therapy, so-called "end-to-end" tests are intended to cover all steps from therapy planning to follow-up to fulfill the high demands on quality assurance. As magnetic resonance imaging (MRI) gains growing importance in the treatment process and established phantoms (such as the Alderson head) cannot be used for those tests, novel multimodality phantoms have to be developed. Here, we present a feasibility study for such a customizable multimodality head phantom. We used a set of patient CT images as the basis for the anthropomorphic head shape. The recipient - consisting of an epoxy resin - was produced using rapid prototyping (3D printing). The phantom recipient includes a nasal air cavity, two soft tissues volumes and cranial bone. Additionally a spherical tumor volume was positioned in the center. The volumes were filled with dipotassium phosphate-based cranial bone surrogate, agarose gel, and distilled water. The tumor volume was filled with normoxic dosimetr...

Gallas, Raya R; Runz, Armin; Niebuhr, Nina I; Jäkel, Oliver; Greilich, Steffen

2014-01-01T23:59:59.000Z

216

Sub-surface characterization and three dimensional profiling of semiconductors by magnetic resonance force microscopy  

SciTech Connect (OSTI)

This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project successfully developed a magnetic resonance force microscope (MRFM) instrument to mechanically detect magnetic resonance signals. This technique provides an intrinsically subsurface, chemical-species-specific probe of structure, constituent density and other properties of materials. As in conventional magnetic resonance imaging (MRI), an applied magnetic field gradient selects a well defined volume of the sample for study. However mechanical detection allows much greater sensitivity, and this in turn allows the reduction of the size of the minimum resolvable volume. This requires building an instrument designed to achieve nanometer-scale resolution at buried semiconductor interfaces. High-resolution, three-dimensional depth profiling of semiconductors is critical in the development and fabrication of semiconductor devices. Currently, there is no capability for direct, high-resolution observation and characterization of dopant density, and other critical features of semiconductors. The successful development of MRFM in conjunction with modifications to improve resolution will enable for the first time detailed structural and electronic studies in doped semiconductors and multilayered nanoelectronic devices, greatly accelerating the current pace of research and development.

Hammel, P.C.; Moore, G.; Roukes, M.; Zhenyong Zhang

1996-10-01T23:59:59.000Z

217

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

218

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

219

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

220

Resonance conditions  

E-Print Network [OSTI]

Non-linear parametric resonances occur frequently in nature. Here we summarize how they can be studied by means of perturbative methods. We show in particular how resonances can affect the motion of a test particle orbiting in the vicinity of a compact object. These mathematical toy-models find application in explaining the structure of the observed kHz Quasi-Periodic Oscillations: we discuss which aspects of the reality naturally enter in the theory, and which one still remain a puzzle.

P. Rebusco

2005-10-14T23:59:59.000Z

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.


221

MRI Ventures | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429Lacey,(MonasterLowell Point,ECO Auger < MHKHydrodynamics21stBelmarMRI

222

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

223

Longitudinal, intermodality registration of quantitative breast PET and MRI data acquired before and during neoadjuvant chemotherapy: Preliminary results  

SciTech Connect (OSTI)

Purpose: The authors propose a method whereby serially acquired DCE-MRI, DW-MRI, and FDG-PET breast data sets can be spatially and temporally coregistered to enable the comparison of changes in parameter maps at the voxel level. Methods: First, the authors aligned the PET and MR images at each time point rigidly and nonrigidly. To register the MR images longitudinally, the authors extended a nonrigid registration algorithm by including a tumor volume-preserving constraint in the cost function. After the PET images were aligned to the MR images at each time point, the authors then used the transformation obtained from the longitudinal registration of the MRI volumes to register the PET images longitudinally. The authors tested this approach on ten breast cancer patients by calculating a modified Dice similarity of tumor size between the PET and MR images as well as the bending energy and changes in the tumor volume after the application of the registration algorithm. Results: The median of the modified Dice in the registered PET and DCE-MRI data was 0.92. For the longitudinal registration, the median tumor volume change was ?0.03% for the constrained algorithm, compared to ?32.16% for the unconstrained registration algorithms (p = 8 × 10{sup ?6}). The medians of the bending energy were 0.0092 and 0.0001 for the unconstrained and constrained algorithms, respectively (p = 2.84 × 10{sup ?7}). Conclusions: The results indicate that the proposed method can accurately spatially align DCE-MRI, DW-MRI, and FDG-PET breast images acquired at different time points during therapy while preventing the tumor from being substantially distorted or compressed.

Atuegwu, Nkiruka C.; Williams, Jason M. [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 and Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675 (United States)] [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 and Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675 (United States); Li, Xia; Arlinghaus, Lori R. [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 (United States)] [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 (United States); Abramson, Richard G. [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 (United States) [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 (United States); Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675 (United States); Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States); Chakravarthy, A. Bapsi [Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-5671 and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States)] [Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-5671 and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States); Abramson, Vandana G. [Department of Medical Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6307 and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States)] [Department of Medical Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6307 and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States); Yankeelov, Thomas E., E-mail: thomas.yankeelov@vanderbilt.edu [Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 (United States); Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675 (United States); Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37240-1807 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States); Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1631 (United States); Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838 (United States)

2014-05-15T23:59:59.000Z

224

Hemangioma of the Interatrial Septum: CT and MRI Features  

SciTech Connect (OSTI)

Hemangioma of the heart is a rare primary benign tumor mainly appearing as enhancing, homogenous, well-circumscribed mass. We report a case of a 61-year-old asymptomatic woman, whose echocardiography showed a cardiac mass, which was described as the atypical myxoma of the right atrium. For further imaging, contrast-enhanced computed tomography and cardiac magnetic resonance imaging were undertaken, which showed a tumor located in the interatrial septum with imaging characteristics of hemangioma. In the literature, cardiac hemangioma is usually described as an intensely enhancing mass. In our opinion, early peripheral puddling of contrast material with filling in on delayed images is a typical pattern of its enhancement. This characteristic, in addition to high signal intensity on T2-weighted images, allows differentiation of a hemangioma from other benign and malignant tumors.

Hrabak-Paar, Maja, E-mail: majahrabak@gmail.com [University Hospital Center Zagreb, University of Zagreb School of Medicine, Department of Diagnostic and Interventional Radiology (Croatia); Huebner, Marisa [University Hospital Mainz (Germany); Stern-Padovan, Ranka; Lusic, Mario [University Hospital Center Zagreb, University of Zagreb School of Medicine, Department of Diagnostic and Interventional Radiology (Croatia)

2011-02-15T23:59:59.000Z

225

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:...

226

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

227

BIOSIGNAL 2002 Tagged cardiac MR images analysis  

E-Print Network [OSTI]

in cardiac tagged MR images analysis. 1 Introduction The non invasive assessment of the cardiac functionBIOSIGNAL 2002 Tagged cardiac MR images analysis A. HISTACE, L. HERMAND, C. CAVARO-MENARD LISA used by tagged MRI displays a deformable dark grid which sticks to the contraction of myocardium (fig.1

Histace, Aymeric

228

Molecular imaging in oncology: the acceptance of PET/CT and the emergence of MR/PET imaging  

E-Print Network [OSTI]

CT—Computed tomography . PET—Positron Emission Tomography .body imaging with MRI or PET/CT: the future for single-Sollitto RA et al (2009) 18F-FDG PET/CT of transitional cell

Schiepers, Christiaan; Dahlbom, Magnus

2011-01-01T23:59:59.000Z

229

4D tumor centroid tracking using orthogonal 2D dynamic MRI: Implications for radiotherapy planning  

SciTech Connect (OSTI)

Purpose: Current pretreatment, 4D imaging techniques are suboptimal in that they sample breathing motion over a very limited “snapshot” in time. Heretofore, long-duration, 4D motion characterization for radiotherapy planning, margin optimization, and validation have been impractical for safety reasons, requiring invasive markers imaged under x-ray fluoroscopy. To characterize 3D tumor motion and associated variability over durations more consistent with treatments, the authors have developed a practical dynamic MRI (dMRI) technique employing two orthogonal planes acquired in a continuous, interleaved fashion.Methods: 2D balanced steady-state free precession MRI was acquired continuously over 9–14 min at approximately 4 Hz in three healthy volunteers using a commercial 1.5 T system; alternating orthogonal imaging planes (sagittal, coronal, sagittal, etc.) were employed. The 2D in-plane pixel resolution was 2 × 2 mm{sup 2} with a 5 mm slice profile. Simultaneous with image acquisition, the authors monitored a 1D surrogate respiratory signal using a device available with the MRI system. 2D template matching-based anatomic feature registration, or tracking, was performed independently in each orientation. 4D feature tracking at the raw frame rate was derived using spline interpolation.Results: Tracking vascular features in the lung for two volunteers and pancreatic features in one volunteer, the authors have successfully demonstrated this method. Registration error, defined here as the difference between the sagittal and coronal tracking result in the SI direction, ranged from 0.7 to 1.6 mm (1?) which was less than the acquired image resolution. Although the healthy volunteers were instructed to relax and breathe normally, significantly variable respiration was observed. To demonstrate potential applications of this technique, the authors subsequently explored the intrafraction stability of hypothetical tumoral internal target volumes and 3D spatial probability distribution functions. The surrogate respiratory information allowed the authors to show how this technique can be used to study correlations between internal and external (surrogate) information over these prolonged durations. However, compared against the gold standard of the time stamps in the dMRI frames, the temporal synchronization of the surrogate 1D respiratory information was shown to be likely unreliable.Conclusions: The authors have established viability of a novel and practical pretreatment, 4D tumor centroid tracking method employing a commercially available dynamic MRI sequence. Further developments from the vendor are likely needed to provide a reliably synchronized surrogate 1D respiratory signal, which will likely broaden the utility of this method in the pretreatment radiotherapy planning context.

Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 and Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905 (United States)] [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 and Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Flammang, Aaron; Shea, Steven M. [Center for Applied Medical Imaging, Siemens Corporation, Corporate Technology, Baltimore, Maryland 21205 (United States)] [Center for Applied Medical Imaging, Siemens Corporation, Corporate Technology, Baltimore, Maryland 21205 (United States); Hales, Russell; Herman, Joseph; Lee, Junghoon; McNutt, Todd; Roland, Teboh; Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States)] [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States)

2013-09-15T23:59:59.000Z

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

Novel geometry gradient coils for MRI designed by genetic algorithm  

E-Print Network [OSTI]

in the Steady State High Performance Computing Facility Herchel Smith Laboratory for Medicinal Chemistry Message Passing Interface Magnetic Resonance Imaging Positron Emission Tomography Radio frequency Electro-motive force Root mean squared IX & x... by the intro­ duction of high performance computing. One of the major disadvantages of this approach . to gradient design is the amount of time taken to produce results, and high performance computing has the potential to reduce this. The amount by which a...

Williams, Guy Barnett

2001-06-19T23:59:59.000Z

232

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.

233

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

E-Print Network [OSTI]

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

234

Non-invasive NMR thermometry and temperature monitering using the proton resonance frequenccy method  

E-Print Network [OSTI]

of research for the Magnetic Resonance Systems Laboratory (MRSL). The theory and principles of the PRF method are thoroughly investigated. The 2.OT MRI system is tested for phase and temporal stability and is determined whether it is capable of accurate NMR...

Naphuket, Sood Ratanadilok

1997-01-01T23:59:59.000Z

235

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

236

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

237

application ultrafast mri: Topics by E-print Network  

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

Jeffrey A. 11 Applications of MRI in Fluidics: Single Echo Acquisition MRI Toward Microfluidics Texas A&M University - TxSpace Summary: (13,14). A handheld lab-on-a-chip may...

238

Efficient MR image reconstruction for compressed MR imaging Junzhou Huang  

E-Print Network [OSTI]

to be very powerful for the MR image reconstruction. First, we decompose the original problem into L1 and TV.V. All rights reserved. 1. Introduction Magnetic Resonance (MR) imaging has been widely used in medical. Computation became the bottleneck that prevented this good model (1) from being used in practical MR image

Huang, Junzhou

239

Efficient MR Image Reconstruction for Compressed MR Imaging  

E-Print Network [OSTI]

demonstrate the superior performance of the proposed algorithm for com- pressed MR image reconstruction. 1 [1][2] show that it is possi- ble to accurately reconstruct the Magnetic Resonance (MR) images from for real MR images. Computation became the bottleneck that prevented this good model (1) from being used

Huang, Junzhou

240

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

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241

Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates  

SciTech Connect (OSTI)

This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C{sub 3}A or 3CaO {center_dot} Al{sub 2}O{sub 3}) and Na-doped tricalcium aluminate (orthorhombic C{sub 3}A or Na{sub 2}Ca{sub 8}Al{sub 6}O{sub 18}), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by {sup 27}Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C{sub 3}A hydration during the early stages. There are differences in the hydration mechanism between the two types of C{sub 3}A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C{sub 3}A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C{sub 3}A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping.

Kirchheim,, A. P.; Dal Molin, D.C.; Emwas, Abdul-Hamid; Provis, J.L.; Fischer, P.; Monteiro, P.J.M.

2010-12-01T23:59:59.000Z

242

Pore-structure determinations of silica aerogels by {sup 129}Xe NMR spectroscopy and imaging.  

SciTech Connect (OSTI)

Silica aerogels represent a new class of open-pore materials with pore dimensions on a scale of tens of nanometers, and are thus classified as mesoporous materials. In this work, we show that the combination of NMR spectroscopy and chemical-shift selective magnetic resonance imaging (MRI) can resolve some of the important aspects of the structure of silica aerogels. The use of xenon as a gaseous probe in combination with spatially resolved NMR techniques is demonstrated to be a powerful, new approach for characterizing the average pore structure and steady-state spatial distributions of xenon atoms in different physicochemical environments. Furthermore, dynamic NMR magnetization transfer experiments and pulsed-field gradient (PFG) measurements have been used to characterize exchange processes and diffusive motion of xenon in samples at equilibrium. In particular, this new NMR approach offers unique information and insights into the nanoscopic pore structure and microscopic morphology of aerogels and the dynamical behavior of occluded adsorbates. MRI provides spatially resolved information on the nature of the flaw regions found in these materials. Pseudo-first-order rate constants for magnetization transfer among the bulk and occluded xenon phases indicate xenon-exchange rate constants on the order of 1 s-1 for specimens having volumes of 0.03 cm3. PFG diffusion measurements show evidence of anisotropic diffusion for xenon occluded within aerogels, with nominal self-diffusivity coefficients on the order of D= 10-3cm2/s.

Gregory, D. M.; Gerald, R. E., II; Botto, R. E.; Chemistry

1998-04-01T23:59:59.000Z

243

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

244

artery magnetic resonance: Topics by E-print Network  

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

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Whole Brain Isotropic Arterial Spin Labeling Magnetic Resonance Imaging in a transgenic mouse...

245

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

246

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...

247

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...

248

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

249

Nanomechanical resonance detector  

DOE Patents [OSTI]

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

Grossman, Jeffrey C; Zettl, Alexander K

2013-10-29T23:59:59.000Z

250

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

251

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

252

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

253

Figure 1. Illustration of GARSE reconstruction for 2D imaging. Filled  

E-Print Network [OSTI]

/temporal resolution and to reduce scan time and SAR [1,2]. All P-MRI methods require coil sensitivity calibration to the patient motion between coil calibration and imaging scans. For such cases, autocalibration is preferable

Utah, University of

254

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

E-Print Network [OSTI]

in Magnetic Resonance Imaging by Padraig J. Cantillon-Murphy B.E., Electrical and Electronic EngineeringOn 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

255

Array combination for parallel imaging in Magnetic Resonance Imaging  

E-Print Network [OSTI]

......................................103 Figure 51. Diagram of geometry used...........................................................................104 Figure 52. 64 element 8x8 grid array SNR map using 64 receivers. ............................105 Figure 53. 64 element 8x8 grid...-factor maps for point combined array......................................................117 Figure 63. SENSE reconstructions using point combined array...................................118 Figure 64. Grid array geometry used for simulation...

Spence, Dan Kenrick

2007-09-17T23:59:59.000Z

256

atypical mri features: Topics by E-print Network  

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

al. (2004) found that patients treated with typical antipsychotics exhibited 2 3-D MRI Brain Scan Feature Classification Using an Oct-tree Representation Computer Technologies and...

257

Magnetite-Loaded Polymeric Micelles as Ultrasensitive Magnetic-Resonance  

E-Print Network [OSTI]

Magnetite-Loaded Polymeric Micelles as Ultrasensitive Magnetic-Resonance Probes** By Hua Ai* Polymeric micelles offer a powerful multifunctional plat- form for drug delivery and diagnostic imaging- tions, polymeric micelles have also received increasing atten- tion in diagnostic imaging applications

Gao, Jinming

258

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.

259

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

260

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

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

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...

262

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

263

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

264

Resonant snubber inverter  

DOE Patents [OSTI]

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

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

1997-06-24T23:59:59.000Z

265

Resonant snubber inverter  

DOE Patents [OSTI]

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

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

1997-01-01T23:59:59.000Z

266

Narrowband resonant transmitter  

DOE Patents [OSTI]

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

Hutchinson, Donald P.; Simpson, Marcus L.; Simpson, John T.

2004-06-29T23:59:59.000Z

267

Electron contamination modeling and reduction in a 1 T open bore inline MRI-linac system  

SciTech Connect (OSTI)

Purpose: A potential side effect of inline MRI-linac systems is electron contamination focusing causing a high skin dose. In this work, the authors reexamine this prediction for an open bore 1 T MRI system being constructed for the Australian MRI-Linac Program. The efficiency of an electron contamination deflector (ECD) in purging electron contamination from the linac head is modeled, as well as the impact of a helium gas region between the deflector and phantom surface for lowering the amount of air-generated contamination. Methods: Magnetic modeling of the 1 T MRI was used to generate 3D magnetic field maps both with and without the presence of an ECD located immediately below the MLC’s. Forty-seven different ECD designs were modeled and for each the magnetic field map was imported into Geant4 Monte Carlo simulations including the linac head, ECD, and a 30 × 30 × 30 cm{sup 3} water phantom located at isocenter. For the first generation system, the x-ray source to isocenter distance (SID) will be 160 cm, resulting in an 81.2 cm long air gap from the base of the ECD to the phantom surface. The first 71.2 cm was modeled as air or helium gas, with the latter encased between two windows of 50 ?m thick high density polyethlyene. 2D skin doses (at 70 ?m depth) were calculated across the phantom surface at 1 × 1 mm{sup 2} resolution for 6 MV beams of field size of 5 × 5, 10 × 10, and 20 × 20 cm{sup 2}. Results: The skin dose was predicted to be of similar magnitude as the generic systems modeled in previous work, 230% to 1400% ofD {sub max} for 5 × 5 to 20 × 20 cm{sup 2}, respectively. Inclusion of the ECD introduced a nonuniformity to the MRI imaging field that ranged from ?20 to ?140 ppm while the net force acting on the ECD ranged from ?151 N to ?1773 N. Various ECD designs were 100% efficient at purging the electron contamination into the ECD magnet banks; however, a small percentage were scattered back into the beam and continued to the phantom surface. Replacing a large portion of the extended air-column between the ECD and phantom surface with helium gas is a key element as it significantly minimized the air-generated contamination. When using an optimal ECD and helium gas region, the 70 ?m skin dose is predicted to increase moderately inside a small hot spot over that of the case with no magnetic field present for the jaw defined square beams examined here. These increases include from 12% to 40% of D {sub max} for 5 × 5 cm{sup 2}, 18% to 55% of D {sub max} for 10 × 10 cm{sup 2}, and from 23% to 65% of D {sub max} for 20 × 20 cm{sup 2}. Conclusions: Coupling an efficient ECD and helium gas region below the MLCs in the 160 cm isocenter MRI-linac system is predicted to ameliorate the impact electron contamination focusing has on skin dose increases. An ECD is practical as its impact on the MRI imaging distortion is correctable, and the mechanical forces acting on it manageable from an engineering point of view.

Oborn, B. M. [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia)] [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Kolling, S. [Sydney Medical School, University of Sydney, NSW 2006 (Australia)] [Sydney Medical School, University of Sydney, NSW 2006 (Australia); Metcalfe, P. E. [Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia)] [Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Crozier, S. [School of Information Technology and Electric Engineering, University of Queensland, QLD 4072 (Australia)] [School of Information Technology and Electric Engineering, University of Queensland, QLD 4072 (Australia); Litzenberg, D. W. [Department of Radiation Oncology, University of Michigan Hospital and Health Systems, Ann Arbor, Michigan 48109 (United States)] [Department of Radiation Oncology, University of Michigan Hospital and Health Systems, Ann Arbor, Michigan 48109 (United States); Keall, P. J. [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia)] [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia)

2014-05-15T23:59:59.000Z

268

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

269

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

E-Print Network [OSTI]

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

270

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

271

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.

Zettl, Alex K. (Kensington, CA); Jensen, Kenneth J. (Berkeley, CA); Girit, Caglar (Albany, CA); Mickelson, William E. (San Francisco, CA); Grossman, Jeffrey C. (Berkeley, CA)

2011-03-29T23:59:59.000Z

272

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

273

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

274

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

275

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

276

Resonant dielectric metamaterials  

DOE Patents [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

277

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

278

Resonant nonlinear ultrasound spectroscopy  

DOE Patents [OSTI]

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

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

2001-01-01T23:59:59.000Z

279

Hepatocarcinogenesis tumor grading correlated with in vivo image-guided {sup 1}H-NMR spectroscopy in a rat model  

SciTech Connect (OSTI)

Hepatocellular carcinoma (HCC) is a common malignancy worldwide, the occurrence of which is unevenly distributed. Most hepatocellular carcinoma cases present late and have a poor prognosis; therefore, early diagnosis is essential to prolong survival. Differential diagnosis with magnetic resonance imaging (MRI) is difficult. We studied the feasibility of using magnetic resonance spectroscopy (MRS) at 7.0 T for the diagnosis and grading of liver tumors. An animal model of hepatocarcinogenesis was used, which allowed tumor progression from precancerous lesions to hepatocellular carcinomas. This study was focused primarily on the grading of the tumors and its correlation with the ratio between the MRS peaks arising from MRS-detected lipid hydrogens (0.9, 1.3 and 5.3 ppm) and compared to the {gamma}-methylene hydrogens of glutamate (Glu) and glutamine (Gln) which was used as an internal reference (2.4 ppm). The lipid methylene hydrogen (1.3 ppm) to (Glu + Gln) ratio was found to correlate with the formation of differentiated small foci and (precancerous) hepatic nodules, whereas the unsaturated olefinic lipid hydrogen (5.3 ppm) to (Glu + Gln) ratio was able to correlate with the formation of late stage tumors such as adenomas and hepatocellular carcinomas. The results of our study suggest that MRS-detected alterations in lipid metabolism can be correlated with the grading of liver tumor tissue at different stages during the carcinogenesis process.

Towner, Rheal A. [Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, 825 N.E. 13th Street, Oklahoma City, OK 73104 (United States) and North Queensland Magnetic Resonance Centre and Department of Physiology and Pharmacology, James Cook University, Townsville, Queensland (Australia)]. E-mail: Rheal-Towner@omrf.ouhsc.edu; Foley, Lesley M. [North Queensland Magnetic Resonance Centre and Department of Physiology and Pharmacology, James Cook University, Townsville, Queensland (Australia); Painter, Dorothy M. [Department of Anatomical Pathology, Royal Prince Alfred Hospital, Sydney, New South Wales (Australia)

2005-09-01T23:59:59.000Z

280

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

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

Technical Note Functional MRI of the Thoracic Spinal Cord During  

E-Print Network [OSTI]

spinal cord using a HASTE sequence on a 3 Tesla MRI system. Results: Signal increases were observed neuronal activity related to both sensory and motor function. Although most of these studies have focused

Smith, Stephen D.

282

asl perfusion mri: Topics by E-print Network  

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

high-resolution fMRI in the primate brain using a novel vertical large-bore 7 Tesla setup J. Pfeuffer1 Computer Technologies and Information Sciences Websites Summary:...

283

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

284

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

285

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.

286

Distinct regions of right temporo-parietal junction are selective for theory of mind and exogenous attention  

E-Print Network [OSTI]

In functional magnetic resonance imaging (fMRI) studies, a cortical region in the right temporo-parietal junction (RTPJ) is recruited when participants read stories about people's thoughts (‘Theory of Mind’). Both fMRI and ...

Triantafyllou, Christina

287

arm wrist abdominal: Topics by E-print Network  

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

with multiple sclerosis can be eVectively di Miall, Chris 8 Design of an MRI compatible robot for wrist rehabilitation MIT - DSpace Summary: Magnetic Resonance Imaging (MRI) can be...

288

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...

289

Content Based Image Retrieval based on Wavelet Transform coefficients distribution  

E-Print Network [OSTI]

: visible, ultrasound, X-ray tomography, MRI, nuclear imaging, etc... Thus for instance, Lund University wavelets (used in JPEG-2000) are tested and we also introduce an adapted wavelet to improve results. We are used in order to test our algorithms. 1) Diabetic retinopathy database: The diabetic retinopa- thy (DR

Boyer, Edmond

290

(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

291

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

292

Performing temperature feedback controlled tissue photo-coagulation using magnetic resonance thermometry  

E-Print Network [OSTI]

controlled photo-coagulation using magnetic resonance imaging as the non-invasive means of temperature feedback. The desired coagulation depth was controlled at a constant temperature of 40 degrees for different amounts of time and the actual coagulation...

Sampath, Smita

1999-01-01T23:59:59.000Z

293

Optically Enhanced Magnetic Resonance  

E-Print Network [OSTI]

, like spatial structures or molecular dynamics. While the direct excitation of nuclear spin transitions.1 Motivation The physical mechanism of nuclear magnetic resonance spectroscopy, the excitation of transitions light for polarizing the spin system or for observing its dynamics. This possibility arises from

Suter, Dieter

294

Proton resonance spectroscopy  

SciTech Connect (OSTI)

This report discusses the following topics: Complete Level Scheme for {sup 30}P; A Search for Resonances Suitable for Tests of Detailed-Balance Violation; The Fourier Transform as a Tool for Detecting Chaos; Entrance Channel Correlations in p + {sup 27}Al; The Parity Dependence of Level Densities in {sup 49}V; and A Computer Program for the Calculation of Angular Momentum Coupling.

Shriner, J.F. Jr.

1991-11-01T23:59:59.000Z

295

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

296

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...

297

Voltage tunable microwave ferrite resonator  

E-Print Network [OSTI]

A novel method of implementing a tunable resonator using an applied voltage is presented. Stress is used to tune a microstrip resonator fabricated on a polycrystalline ferrite substrate. The stress was applied either ...

Oates, Daniel E.

298

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

299

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

300

Magnetic Resonance Facility (Fact Sheet)  

SciTech Connect (OSTI)

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

Not Available

2012-03-01T23:59:59.000Z

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

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

302

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

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

in soft tissues, such as the brain. Several techniques... for automatically segmenting brain tissues in MRI scans of the head have recently been developed. One goal... in MRI is...

303

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.

304

E-Print Network 3.0 - axial loaded mri Sample Search Results  

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

for new MRI- compatible Source: Mavroidis, Constantinos - Department of Mechanical and Industrial Engineering, Northeastern University Collection: Engineering 2 370 IEEEASME...

305

SHEARING BOX SIMULATIONS OF THE MRI IN A COLLISIONLESS PLASMA Prateek Sharma and Gregory W. Hammett  

E-Print Network [OSTI]

of the MRI in a collision- less plasma, focusing on local simulations in the shearing box limit. Quataert et

Hammett, Greg

306

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

307

Tandem resonator reflectance modulator  

DOE Patents [OSTI]

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

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

1994-09-06T23:59:59.000Z

308

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.

309

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

E-Print Network [OSTI]

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

Hadjikhani, Nouchine

310

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.

311

Robust automatic rigid registration of MRI and X-ray using external fiducial markers for XFM-guided interventional procedures  

SciTech Connect (OSTI)

Purpose: In X-ray fused with MRI, previously gathered roadmap MRI volume images are overlaid on live X-ray fluoroscopy images to help guide the clinician during an interventional procedure. The incorporation of MRI data allows for the visualization of soft tissue that is poorly visualized under X-ray. The widespread clinical use of this technique will require fully automating as many components as possible. While previous use of this method has required time-consuming manual intervention to register the two modalities, in this article, the authors present a fully automatic rigid-body registration method. Methods: External fiducial markers that are visible under these two complimentary imaging modalities were used to register the X-ray images with the roadmap MR images. The method has three components: (a) The identification of the 3D locations of the markers from a full 3D MR volume, (b) the identification of the 3D locations of the markers from a small number of 2D X-ray fluoroscopy images, and (c) finding the rigid-body transformation that registers the two point sets in the two modalities. For part (a), the localization of the markers from MR data, the MR volume image was thresholded, connected voxels were segmented and labeled, and the centroids of the connected components were computed. For part (b), the X-ray projection images, produced by an image intensifier, were first corrected for distortions. Binary mask images of the markers were created from the distortion-corrected X-ray projection images by applying edge detection, pattern recognition, and image morphological operations. The markers were localized in the X-ray frame using an iterative backprojection-based method which segments voxels in the volume of interest, discards false positives based on the previously computed edge-detected projections, and calculates the locations of the true markers as the centroids of the clusters of voxels that remain. For part (c), a variant of the iterative closest point method was used to find correspondences between and register the two sets of points computed from MR and X-ray data. This knowledge of the correspondence between the two point sets was used to refine, first, the X-ray marker localization and then the total rigid-body registration between modalities. The rigid-body registration was used to overlay the roadmap MR image onto the X-ray fluoroscopy projections. Results: In 35 separate experiments, the markers were correctly registered to each other in 100% of the cases. When half the number of X-ray projections was used (10 X-ray projections instead of 20), the markers were correctly registered in all 35 experiments. The method was also successful in all 35 experiments when the number of markers was (retrospectively) halved (from 16 to 8). The target registration error was computed in a phantom experiment to be less than 2.4 mm. In two in vivo experiments, targets (interventional devices with pointlike metallic structures) inside the heart were successfully registered between the two modalities. Conclusions: The method presented can be used to automatically register a roadmap MR image to X-ray fluoroscopy using fiducial markers and as few as ten X-ray projections.

George, Ashvin K.; Sonmez, Merdim; Lederman, Robert J.; Faranesh, Anthony Z. [Translational Medicine Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1538 (United States); Translational Medicine Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1538 (United States) and Biomedical Engineering Institute, Bogazici University, Istanbul 34684 (Turkey); Translational Medicine Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1538 (United States)

2011-01-15T23:59:59.000Z

312

MRI Techniques for Noninvasive Monitoring of Transplanted Organs  

E-Print Network [OSTI]

(microimaging small animal mice, high resolution) ­ 2 Brucker Avance DRX (4.7 T and 7.0 T) MRI/MRS ­ Home the dynamic behavior of the transplanted organ Automatic segmentation of kidneys & their internal structures;12 Segmentation Algorithm Energy minimization by level set Identify the boundary of the cortex Preprocessing

Moura, José

313

Multifunctional Polymeric Micelles as Cancer-Targeted, MRI-Ultrasensitive  

E-Print Network [OSTI]

Multifunctional Polymeric Micelles as Cancer-Targeted, MRI-Ultrasensitive Drug Delivery Systems describe the development of multifunctional polymeric micelles with cancer-targeting capability via rv 3 and rv 3-specific cytotoxic response of these multifunctional polymeric micelles. Over the past several

Gao, Jinming

314

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

315

Test Images  

E-Print Network [OSTI]

Test Images. I hope to have a set of test images for the course soon. Some images are available now; some will have to wait until I can find another 100-200

316

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

317

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

318

Regarding Confinement Resonances  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298,NIST 800-53ReferenceRegarding Confinement Resonances

319

Proton Resonance Spectroscopy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedlesAdvanced Photon SourceProton ChannelResonance

320

DISSIPATIVE DIVERGENCE OF RESONANT ORBITS  

SciTech Connect (OSTI)

A considerable fraction of multi-planet systems discovered by the observational surveys of extrasolar planets reside in mild proximity to first-order mean-motion resonances. However, the relative remoteness of such systems from nominal resonant period ratios (e.g., 2:1, 3:2, and 4:3) has been interpreted as evidence for lack of resonant interactions. Here, we show that a slow divergence away from exact commensurability is a natural outcome of dissipative evolution and demonstrate that libration of critical angles can be maintained tens of percent away from nominal resonance. We construct an analytical theory for the long-term dynamical evolution of dissipated resonant planetary pairs and confirm our calculations numerically. Collectively, our results suggest that a significant fraction of the near-commensurate extrasolar planets are in fact resonant and have undergone significant dissipative evolution.

Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Morbidelli, Alessandro, E-mail: kbatygin@gps.caltech.edu [Departement Cassiopee, Universite de Nice-Sophia Antipolis, Observatoire de la Cote d'Azur, F-06304 Nice (France)

2013-01-01T23:59:59.000Z

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

Image Analysis  

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

Recognition Image Analysis and Recognition Snapshot1498121slicesqResedison Fibers permeating imaged material (Courtesy: Bale, Loring, Perciano and Ushizima) Imagery coming from...

322

Cyclotron subharmonics resonant (CSR) heating  

SciTech Connect (OSTI)

The cyclotron subharmonics resonant (CSR) heating mechanism is studied using particle simulation codes with an emphasis on the relationship between CSR and the nonlinear Landua damping.

Abe, H.

1994-01-01T23:59:59.000Z

323

The IPNS resonance detector spectrometer  

SciTech Connect (OSTI)

In the resonance detector method of neutron spectroscopy, a foil is placed in the scattered neutron beam and scattered neutrons having the resonance energy are detected by detecting the capture gammas resulting from the resonance absorption of the neutrons. A prototype resonance detector spectrometer called the Electron Volt Spectrometer (EVS) has been built and operated. The instrument is described, the current understanding of the background of the instrument is discussed, software developed to simulate the detector efficiency is described and compared with experimental results, and a test of the use of foil-thickness difference techniques to improve resolution is presented. (LEW)

Crawford, R.K.

1986-01-01T23:59:59.000Z

324

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...

325

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

326

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

327

Image Fusion for MR Bias Stochastic Systems Group  

E-Print Network [OSTI]

We can target T1 and T2 through appropriate selection of TE and TR. #12;Image Reconstruction The MRImage Fusion for MR Bias Correction Ayres Fan Stochastic Systems Group Joint work with W. Wells, J. Fisher, M. Cetin, S. Haker, A. Willsky, B. Mulkern #12;Magnetic Resonance The magnetic resonance (MR

Willsky, Alan S.

328

Transmission resonances in the bipolar quantum resonant tunneling transistor  

E-Print Network [OSTI]

MODEL CALCULATIONS Simple Wells Barriers and Nonparabolicity 16 20 IV CONCLUSION: DEVICES AND RESULTS 26 Collector Geometry Profile Evolution Results . 27 30 32 REFERENCES APPENDIX 36 A COMPUTER PROGRAMS Transmission (Parabolic...) . Transmission (Nonparabolic) Bound States and Wavefunctions (Parabolic). . . . Bound States and Wavefunctions (Nonparabolic) . Resonant Slopes (Parabolic) . Resonant Slopes (Nonparabolic) 37 41 46 52 59 64 VITA 68 LIST OF FIGURES FIGURE Page...

Mondragon, Antonio Richard

1996-01-01T23:59:59.000Z

329

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

330

Injectable polymer for in vivo oxygen sensing  

E-Print Network [OSTI]

This thesis documents the synthesis and characterization of an elastomeric polymer that is oxygen sensitive and can be interrogated using Magnetic Resonance Imaging (MRI) or Magnetic Resonance (MR) technology to report the ...

Imaad, Syed M. (Syed Muhammad)

2013-01-01T23:59:59.000Z

331

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

332

Delta connected resonant snubber circuit  

DOE Patents [OSTI]

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

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

1998-01-20T23:59:59.000Z

333

Delta connected resonant snubber circuit  

DOE Patents [OSTI]

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

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

1998-01-01T23:59:59.000Z

334

Transverse-longitudinal integrated resonator  

DOE Patents [OSTI]

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

Hutchinson, Donald P. (Knoxville, TN); Simpson, Marcus L. (Knoxville, TN); Simpson, John T. (Knoxville, TN)

2003-03-11T23:59:59.000Z

335

Reduction of boundary effects in spiral MRI experiment PROMISE  

E-Print Network [OSTI]

Magnetorotational instability (MRI) is one of the most important and most common instabilities in astrophysics, it is widely accepted that it serves as a source of turbulent viscosity in accretion disks -- the most energy efficient objects in the Universe. However it is very difficult to bring this process down on earth and model it in a laboratory experiment. Several different approaches have been proposed, one of the most recent is PROMISE (Potsdam-ROssendorf Magnetorotational InStability Experiment). It consists of a flow of a liquid metal between two rotating cylinders under applied current-free spiral magnetic field. The cylinders must be covered with plates which introduce additional end-effects which alter the flow and make it more difficult to clearly distinguish between MRI stable and unstable state. In this paper we propose simple and inexpensive improvement to the PROMISE experiment which would reduce those undesirable effects.

J. Szklarski

2007-05-21T23:59:59.000Z

336

Auxiliary resonant DC tank converter  

DOE Patents [OSTI]

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

Peng, Fang Z. (Knoxville, TN)

2000-01-01T23:59:59.000Z

337

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, Dougalas C.; Silva, Christopher M.; Bylina, Edward J.; Coleman, William J.; Dilworth, Michael R.; Yang, Mary M.

2003-12-09T23:59:59.000Z

338

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

339

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

340

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

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

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

342

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

343

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

344

Giant resonances in O-16  

E-Print Network [OSTI]

. The solid line indicates the division chosen between the GR peak and the continuum. Giant resonance Y.-W. Lui, H. L. Clark Cyclotron Institute, Texas A&M Universit ~Received 31 May 2001; publishe Giant resonances in 16O have been studied with inelasti... resonance ~GR! ?2001 The American Physical Society1 Y.-W. LUI, H. L. CLARK, AND D. H. YOUNGBLOOD PHYSICAL REVIEW C 64 064308 peak. The procedure used to determine the shape of the con- tinuum was similar to that described in detail in Ref. @7#. The GR...

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

2001-01-01T23:59:59.000Z

345

Postdoctoral Positions In-vivo Optical Imaging and Microscopy of the Living Brain  

E-Print Network [OSTI]

Postdoctoral Positions In-vivo Optical Imaging and Microscopy of the Living Brain Columbia insight into the function and physiology of the living brain. We are particularly interested in exploring brain. Neurovascular coupling is important both because it is the basis of the fMRI BOLD signal

Adams, Mark

346

Refraction corrected transmission ultrasound computed tomography for application in breast imaging  

E-Print Network [OSTI]

-synthesis and 3D cone-beam imaging,4,5 the radiation dose still remains. The use of MRI technology can address Mathematics, Australian National University, Canberra, ACT 2601, Australia Lawrence H. Staibd Department to significant ionizing radiation, which renders short-term follow-up monitoring prohibitive. Furthermore

Mueller, Klaus

347

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

348

People Images  

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

People 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...

349

An fMRI Study of Audiovisual Speech Perception Reveals Multisensory Interactions in Auditory Cortex  

E-Print Network [OSTI]

William Matchin, Kourosh Saberi, Gregory Hickok * DepartmentK, Venezia JH, Matchin W, Saberi K, Hickok G (2013) An fMRI

Okada, Kayoko; Venezia, Jonathan H; Matchin, William; Saberi, Kourosh; Hickok, Gregory; Alain, Claude

2013-01-01T23:59:59.000Z

350

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...

351

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...

352

Frequency Resolved Nanoscale Chemical Imaging of 4,4'-Dimercaptostilbene on Silver  

SciTech Connect (OSTI)

Non-resonant tip-enhanced Raman images of 4,4'-dimercaptostilbene on silver reveal that different vibrational resonances of the reporter are selectively enhanced at different sites on the metal substrate. Sequentially recorded images track molecular diffusion within the diffraction-limited laser spot which illuminates the substrate. In effect, the recorded time resolved (?t = 10 s) pixelated images (25 nm x 8 cm-1) broadcast molecule-local field interactions which take place on much finer scales.

El-Khoury, Patrick Z.; Ueltschi, Tyler W.; Mifflin, Amanda L.; Hu, Dehong; Hess, Wayne P.

2014-11-26T23:59:59.000Z

353

Image alignment  

DOE Patents [OSTI]

Disclosed is a method and device for aligning at least two digital images. An embodiment may use frequency-domain transforms of small tiles created from each image to identify substantially similar, "distinguishing" features within each of the images, and then align the images together based on the location of the distinguishing features. To accomplish this, an embodiment may create equal sized tile sub-images for each image. A "key" for each tile may be created by performing a frequency-domain transform calculation on each tile. A information-distance difference between each possible pair of tiles on each image may be calculated to identify distinguishing features. From analysis of the information-distance differences of the pairs of tiles, a subset of tiles with high discrimination metrics in relation to other tiles may be located for each image. The subset of distinguishing tiles for each image may then be compared to locate tiles with substantially similar keys and/or information-distance metrics to other tiles of other images. Once similar tiles are located for each image, the images may be aligned in relation to the identified similar tiles.

Dowell, Larry Jonathan

2014-04-22T23:59:59.000Z

354

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

355

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

356

Gradient Echo MRI Characterization of Development of Atherosclerosis in the Abdominal Aorta in Watanabe Heritable Hyperlipidemic Rabbits  

SciTech Connect (OSTI)

Purpose. The Watanabe Heritable Hyperlipidemic (WHHL) rabbit provides an important model of spontaneous atherosclerosis. With a strain of WHHL rabbits which do not develop abdominal aorta lumen stenosis even with advanced atherosclerosis, we studied the MRI-histology correlation, and the natural progression of atherosclerosis in the abdominal aorta. In addition, intra-reader segmentation repeatability and scan-rescan reproducibility were assessed. Methods. Two batches of female WHHL rabbits were used. The first batch of 6 rabbits was scanned at 20 weeks old. A second batch of 17 rabbits was scanned at 50 weeks old and then randomly divided into two subgroups: 8 were killed for histologic investigation; 9 were kept alive for follow-up, with repeat scanning a week later to assess scan-rescan reproducibility, and again at 73 weeks old to assess disease progression. MR images were acquired at 4.7 T using a chemical shift selective fat suppression gradient echo with a saturation band suppressing blood signal within the aortic lumen. Five slices per animal were acquired, centered around the renal artery region of the abdominal aorta, with in-plane resolution of 0.195 mm and slice thickness of 3 mm. Results. The coefficient of variation for intra-reader reproducibility for aortic wall thickness measurements was 2.5% for repeat segmentations of the same scans on the same day, but segmentations of these same scans made 8 months later showed a systematic change, suggesting that intra-reader bias as well as increased variability could compromise assessments made over time. Comparative analyses were therefore performed in one postprocessing session. The coefficient of variation for scan-rescan reproducibility for aortic wall thickness was 5.5% for nine pairs of scans acquired a week apart and segmented on the same day. Good MRI-histology correlation was obtained. The MRI-measured mean aortic wall thickness of animals at 20 weeks of age was 76% that of animals at 50 weeks of age (p < 0.001). There was a small increase in aortic wall thickness between 50 and 73 weeks of age, but this was not significant (p > 0.05). The corresponding differences in lumen cross-sectional areas at 20, 50, and 73 weeks of age were not significant. These results were consistent with in-house historical histology data on this strain of rabbits. Conclusions. High-resolution gradient echo MRI can follow disease progression in the WHHL rabbit spontaneous atherosclerosis disease model.

Wang, Yi-Xiang J., E-mail: yi-xiang.wang@astrazeneca.com; Kuribayashi, Hideto [AstraZeneca (United Kingdom); Wagberg, Maria [AstraZeneca (Sweden); Holmes, Andrew P.; Tessier, Jean J.; Waterton, John C. [AstraZeneca (United Kingdom)

2006-08-15T23:59:59.000Z

357

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

358

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

359

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

360

Multi-probe robotic positioner for cryoablation in MRI  

E-Print Network [OSTI]

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

Wu, Faye Y

2012-01-01T23:59:59.000Z

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

Bioengineering 278: Magnetic Resonance Imaging Laboratory Winter 2013  

E-Print Network [OSTI]

the provided piece of pyrolytic carbon (diamagnetic) on the surface of the pink oil phantom so that the carbon and the collection of the center of K-space (the gradient echo). In spin echo mode, the CV tau sets the offset by applying a shim offset in the X direction. The shim offset should perturb the phase of the gradient echoes

California at San Diego, University of

362

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

363

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

364

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

365

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

366

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

367

ischemic (at-risk) Current Research in Magnetic Resonance Imaging  

E-Print Network [OSTI]

killer in the United States, and is responsible for half million deaths and medical costs on the order of $165 billion per year. There are many different types of heart disease (ischemic, valvular, con Department of Electrical Engineering, Viterbi School of EngineeringMing Hsieh Department of Electrical

Southern California, University of

368

Application of Magnetic Resonance (MR) Imaging for the Development and  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mailRadioimmunotherapy of Cancers.Appendix

369

Ultrasensitive Magnetometry and Imaging with NV Diamond  

E-Print Network [OSTI]

-size wire structure to sit directly on the surface of millimeter-scale diamond plate. In contrast to conventional magnetic resonance imaging pulsed ESR was used to measure the Rabi oscillations. From the beating of Rabi oscillations from a "double NV...

Kim, Changdong

2011-08-08T23:59:59.000Z

370

Prediction-Based Compression Ratio Boundaries for Medical Images  

E-Print Network [OSTI]

Prediction-Based Compression Ratio Boundaries for Medical Images Xiaojun Qi Computer Science present prediction-based image compression techniques take advantage of either intra- or inter function. The prediction-based compression technique has been applied on some magnetic resonance (MR) brain

Qi, Xiaojun

371

High resolution photoelectron images and D{sup +} photofragment images following 532-nm photolysis of D{sub 2}  

SciTech Connect (OSTI)

The non-resonant ionization and dissociation of D{sub 2} by intense 532-nm laser light is studied by a variation of the ``Ion Imaging`` technique called ``Velocity Mapping``. Images of the both the photoelectrons and D{sup +} photofragments are obtained and analyzed at two different laser intensities. Results are compared to previous studies and several differences are discussed.

Chandler, D.W.; Neyer, D.W. [Sandia National Labs., Livermore, CA (United States); Heck, A.J. [Univ. of Warwick, Coventry (United Kingdom). Dept. of Chemistry

1998-01-01T23:59:59.000Z

372

Precedence of the Eye Region in Neural Processing of Faces  

E-Print Network [OSTI]

Functional magnetic resonance imaging (fMRI) has revealed multiple subregions in monkey inferior temporal cortex (IT) that are selective for images of faces over other objects. The earliest of these subregions, the posterior ...

Issa, Elias

373

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

374

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

375

Stochastic Resonance: from climate to biology  

E-Print Network [OSTI]

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

Roberto Benzi

2007-02-05T23:59:59.000Z

376

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

377

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.

378

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

379

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

380

Multimodal dataset: Localising face-evoked responses using MEG, EEG, sMRI and  

E-Print Network [OSTI]

channel CTF Omega system; the sMRI data were acquired using a phased-array headcoil on a Siemens Sonata 1 transformation, random #12;2 phase permutation, inverse transformation and outline-masking of each face. Thus-weighted structural MRI of a young male was acquired on a 1.5T Siemens Sonata via an MDEFT sequence

Henson, Rik

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

Real-time MRI-Guided Needle Placement Robot with Integrated Fiber Optic Force Sensing  

E-Print Network [OSTI]

the robot mechanism, controller design, optical modeling and opto-mechanical design of the force sensor. MRI Control Box Needle Driver Module Cartesian Stage Module Piezoelectric Actuators Robot Fig. 1. (LeftReal-time MRI-Guided Needle Placement Robot with Integrated Fiber Optic Force Sensing Hao Su

Camesano, Terri

382

A multichannel, real-time MRI RF power monitor for independent SAR determination  

SciTech Connect (OSTI)

Purpose: Accurate measurements of the RF power delivered during clinical MRI are essential for safety and regulatory compliance, avoiding inappropriate restrictions on clinical MRI sequences, and for testing the MRI safety of peripheral and interventional devices at known RF exposure levels. The goal is to make independent RF power measurements to test the accuracy of scanner-reported specific absorption rate (SAR) over the extraordinary range of operating conditions routinely encountered in MRI. Methods: A six channel, high dynamic range, real-time power profiling system was designed and built for monitoring power delivery during MRI up to 440 MHz. The system was calibrated and used in two 3 T scanners to measure power applied to human subjects during MRI scans. The results were compared with the scanner-reported SAR. Results: The new power measurement system has highly linear performance over a 90 dB dynamic range and a wide range of MRI duty cycles. It has about 0.1 dB insertion loss that does not interfere with scanner operation. The measurements of whole-body SAR in volunteers showed that scanner-reported SAR was significantly overestimated by up to about 2.2 fold. Conclusions: The new power monitor system can accurately and independently measure RF power deposition over the wide range of conditions routinely encountered during MRI. Scanner-reported SAR values are not appropriate for setting exposure limits during device or pulse sequence testing.

El-Sharkawy, AbdEl-Monem M.; Qian Di; Bottomley, Paul A.; Edelstein, William A. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States) and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States)

2012-05-15T23:59:59.000Z

383

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

384

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

E-Print Network [OSTI]

system Xt, XView, Motif, etc. are some of the widely used toolkits. The relationship between Xlib and the toolkits is illustrated in Fig. 12. This study has utilized Xlib and XView using X11R4. All the programs are written on a SparcStation 1. Xlib...

Chung, Maranatha

1993-01-01T23:59:59.000Z

385

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

386

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

387

Computing Images  

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

Computing Images The interior of an automated tape library in Brookhaven's RHIC and ATLAS Computing Facility. Brookhaven engineers in the RHIC and ATLAS Computing Facility....

388

Integrating an automatic classification method into the medical image retrieval process  

E-Print Network [OSTI]

the performance of the University at Buffalo Medical Text and Images Retrieval System (UBMedTIRS). This paper classification process was performed using the Image Retrieval for Medical Application (IRMA) codes3 employed to acquire the image such as x-ray, ultrasound, magnetic resonance measurement, nuclear medicine

Ruiz, Miguel E.

389

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

390

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

391

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

392

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

393

Orbital Resonance and Solar Cycles  

E-Print Network [OSTI]

We present an analysis of planetary moves, encoded in DE406 ephemerides. We show resonance cycles between most planets in Solar System, of differing quality. The most precise resonance - between Earth and Venus, which not only stabilizes orbits of both planets, locks planet Venus rotation in tidal locking, but also affects the Sun: This resonance group (E+V) also influences Sunspot cycles - the position of syzygy between Earth and Venus, when the barycenter of the resonance group most closely approaches the Sun and stops for some time, relative to Jupiter planet, well matches the Sunspot cycle of 11 years, not only for the last 400 years of measured Sunspot cycles, but also in 1000 years of historical record of "severe winters". We show, how cycles in angular momentum of Earth and Venus planets match with the Sunspot cycle and how the main cycle in angular momentum of the whole Solar system (854-year cycle of Jupiter/Saturn) matches with climatologic data, assumed to show connection with Solar output power and insolation. We show the possible connections between E+V events and Solar global p-Mode frequency changes. We futher show angular momentum tables and charts for individual planets, as encoded in DE405 and DE406 ephemerides. We show, that inner planets orbit on heliocentric trajectories whereas outer planets orbit on barycentric trajectories.

P. A. Semi

2009-03-29T23:59:59.000Z

394

NANOSCALE OPTICAL COMPUTING USING RESONANCE ENERGY  

E-Print Network [OSTI]

OPTICAL COMPUTING USING RESONANCE ENERGY TRANSFER LOGIC A NEW NANOSCALE DEVICE BASED ON A SINGLE-MOLECULE OPTICAL PHENOMENON CALLED RESONANCE ENERGY TRANSFER. THIS DEVICE ENABLES A COMPLETE INTEGRATED TECHNOLOGY, PROVIDING A POTENTIAL PATH TO MOLECULAR-SCALE COMPUTING

Lebeck, Alvin R.

395

Nanodiamond graphitization: a magnetic resonance study  

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

on the first nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) study of the high-temperature nanodiamond-to-onion transformation. 1 H, 13 C NMR and...

396

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

397

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

398

Remote NMR/MRI detection of laser polarized gases  

DOE Patents [OSTI]

An apparatus and method for remote NMR/MRI spectroscopy having an encoding coil with a sample chamber, a supply of signal carriers, preferably hyperpolarized xenon and a detector allowing the spatial and temporal separation of signal preparation and signal detection steps. This separation allows the physical conditions and methods of the encoding and detection steps to be optimized independently. The encoding of the carrier molecules may take place in a high or a low magnetic field and conventional NMR pulse sequences can be split between encoding and detection steps. In one embodiment, the detector is a high magnetic field NMR apparatus. In another embodiment, the detector is a superconducting quantum interference device. A further embodiment uses optical detection of Rb--Xe spin exchange. Another embodiment uses an optical magnetometer using non-linear Faraday rotation. Concentration of the signal carriers in the detector can greatly improve the signal to noise ratio.

Pines, Alexander; Saxena, Sunil; Moule, Adam; Spence, Megan; Seeley, Juliette A.; Pierce, Kimberly L.; Han, Song-I; Granwehr, Josef

2006-06-13T23:59:59.000Z

399

Scientific innovation and resonance ionization spectroscopy  

SciTech Connect (OSTI)

An account is presented of the development and appliations of resonance ionization spectroscopy and one atom detection.

Richmond, C.R.

1981-01-01T23:59:59.000Z

400

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

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

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

402

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

403

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

404

An fMRI study of multimodal semantic and phonological processing in reading disabled adolescents  

E-Print Network [OSTI]

2009 /Accepted: 11 September 2009 # The International Dyslexia Association 2009 Abstract Using Dyslexia . fMRI . Performance . Phonology. Reading disability. Semantics Introduction The neurobiology of reading disability An increasing body of research suggests that the core deficit in developmental dyslexia

405

Reliability of two techniques for assessing cerebral iron deposits from structural MRI   

E-Print Network [OSTI]

Purpose: To test the reliability of two computational methods for segmenting cerebral iron deposits (IDs) in the ageing brain, given that its measurement in MRI is challenging due to the similar effect produced by other minerals, especially calcium...

Valdés Hernández, Maria C.; Jeong, Tina H.; Murray, Catherine; Bastin, Mark; Chappell, Francesca M.; Deary, Ian J; Wardlaw, Joanna M

406

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,...

407

Probing the brain’s white matter with diffusion MRI and a tissue dependent diffusion model   

E-Print Network [OSTI]

While diffusion MRI promises an insight into white matter microstructure in vivo, the axonal pathways that connect different brain regions together can only partially be segmented using current methods. Here we present ...

Piatkowski, Jakub Przemyslaw

2014-06-27T23:59:59.000Z

408

Brown Adipose Tissue Quantification in Human Neonates Using Water-Fat Separated MRI  

E-Print Network [OSTI]

1) derived directly from the Siemens operating system, aMRI was performed on a Siemens 3 T Tim Trio system (VB17the re-shim and default Siemens pre-scan preparations. The

2013-01-01T23:59:59.000Z

409

Spiral-In/Out BOLD fMRI for Increased SNR and Reduced Susceptibility Artifacts  

E-Print Network [OSTI]

Spiral-In/Out BOLD fMRI for Increased SNR and Reduced Susceptibility Artifacts Gary H. Glover, and by Glover (9), who used extended coverage of kz-space with windowed reconstruc- tion to provide efficiency

Glover, Gary H.

410

Solid-Cryogen Cooling Technique for Superconducting Magnets of NMR and MRI  

E-Print Network [OSTI]

This paper describes a solid-cryogen cooling technique currently being developed at the M.I.T. Francis Bitter Magnet Laboratory for application to superconducting magnets of NMR and MRI. The technique is particularly ...

Iwasa, Yukikazu

411

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

412

Extraordinary acoustic transmission mediated by Helmholtz resonators  

SciTech Connect (OSTI)

We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of ? radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.

Koju, Vijay [Computation Science Program, Middle Tennessee State University, Murfreesboro, Tennessee 37132 (United States); Rowe, Ebony [Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, Tennessee 37132 (United States); Robertson, William M., E-mail: William.Robertson@mtsu.edu [Computation Science Program, Middle Tennessee State University, Murfreesboro, Tennessee 37132 (United States); Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, Tennessee 37132 (United States)

2014-07-15T23:59:59.000Z

413

Resonance ionization for analytical spectroscopy  

DOE Patents [OSTI]

This invention relates to a method for the sensitive and selective analysis of an atomic or molecular component of a gas. According to this method, the desired neutral component is ionized by one or more resonance photon absorptions, and the resultant ions are measured in a sensitive counter. Numerous energy pathways are described for accomplishing the ionization including the use of one or two tunable pulsed dye lasers.

Hurst, George S. (Oak Ridge, TN); Payne, Marvin G. (Harriman, TN); Wagner, Edward B. (Burchfield Heights, TN)

1976-01-01T23:59:59.000Z

414

Hadronic Resonances from Lattice QCD  

SciTech Connect (OSTI)

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

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

2007-06-16T23:59:59.000Z

415

Hadronic Resonances from Lattice QCD  

SciTech Connect (OSTI)

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

Lichtl, Adam C. [RBRC, Brookhaven National Laboratory, Upton, NY 11973 (United States); Bulava, John; Morningstar, Colin [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Edwards, Robert; Mathur, Nilmani; Richards, David [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Fleming, George [Yale University, New Haven, CT 06520 (United States); Juge, K. Jimmy [Department of Physics, University of the Pacific, Stockton, CA 95211 (United States); Wallace, Stephen J. [University of Maryland, College Park, MD 20742 (United States)

2007-10-26T23:59:59.000Z

416

Electron Paramagnetic Resonance Retrospective Dosimetry  

SciTech Connect (OSTI)

Necessity for, principles of, and general concepts of the electron paramagnetic resonance (EPR) retrospective dosimetry are presented. Also presented and given in details are examples of EPR retrospective dosimetry applications in tooth enamel, bone, and fingernails with focus on general approaches for solving technical and methodological problems. Advantages, drawbacks, and possible future developments are discussed and an extensive bibliography on EPR retrospective dosimetry is provided.

Romanyukha, Alex [Naval Dosimetry Center, 8901 Wisconsin Ave., Bethesda, MD, 20889 (United States); Trompier, Francois [Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France 92262 (France)

2011-05-05T23:59:59.000Z

417

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

418

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

419

Methods for magnetic resonance analysis using magic angle technique  

DOE Patents [OSTI]

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

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

2011-11-22T23:59:59.000Z

420

Multiplexed Echo Planar Imaging for Sub-Second Whole Brain FMRI and Fast Diffusion Imaging  

E-Print Network [OSTI]

, Karla L. Miller5 , Kamil Ugurbil4 , Essa Yacoub4 1 Advanced MRI Technologies, Sebastopol, California

Reber, Paul J.

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

Zinc ferrite nanoparticles as MRI contrast agentsw Carlos Ba rcena,a  

E-Print Network [OSTI]

Zinc ferrite nanoparticles as MRI contrast agentsw Carlos Ba´ rcena,a Amandeep K. Sra,a Girija S, a series of spinel-structured ferrites, MFe2O4 (M = Mn2+ , Fe2+ , Co2+ , Ni2+ ), were reported as novel MRI.e., Mn2+ occupies both A and B sites), whereas the other metal ferrites have an inverse spinel structure

Gao, Jinming

422

Magnetic Resonance Pulse Sequences for Fluorine-19  

E-Print Network [OSTI]

successful cell tracking and quantification of cells. The primary objective of this work was to enable the study of ^(19)F MRI on the Siemens MAGNETOM Verio scanner located at the Texas A&M Institute for Preclinical Studies (TIPS) facility at Texas A...

Terry, Robin

2014-07-11T23:59:59.000Z

423

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

424

System and method for regulating resonant inverters  

DOE Patents [OSTI]

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

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

2007-08-28T23:59:59.000Z

425

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

426

Optomechanical-like coupling between superconducting resonators  

E-Print Network [OSTI]

We propose and analyze a circuit that implements a nonlinear coupling between two superconducting microwave resonators. The resonators are coupled through a superconducting quantum interference device (SQUID) that terminates one of the resonators. This produces a nonlinear interaction on the standard optomechanical form, where the quadrature of one resonator couples to the photon number of the other resonator. The circuit therefore allows for all-electrical realizations of analogs to optomechanical systems, with coupling that can be both strong and tunable. We estimate the coupling strengths that should be attainable with the proposed device, and we find that the device is a promising candidate for realizing the single-photon strong-coupling regime. As a potential application, we discuss implementations of networks of nonlinearly-coupled microwave resonators, which could be used in microwave-photon based quantum simulation.

J. R. Johansson; G. Johansson; Franco Nori

2014-03-18T23:59:59.000Z

427

Feasibility of MR Imaging/MR Spectroscopy-Planned Focal Partial Salvage Permanent Prostate Implant (PPI) for Localized Recurrence After Initial PPI for Prostate Cancer  

SciTech Connect (OSTI)

Purpose: To assess the feasibility of magnetic resonance imaging (MRI)-planned partial salvage permanent prostate implant (psPPI) among patients with biopsy-proven local recurrence after initial PPI without evidence of distant disease. Methods and Materials: From 2003-2009, 15 patients underwent MRI/magnetic resonance spectroscopy (MRS) planning for salvage brachytherapy (psPPI, I-125 [n=14; 144 Gy]; Pd-103 [n=1; 125 Gy]) without hormone therapy. Full dose was prescribed to areas of recurrence and underdosage, without entire prostate implantation. Limiting urethral and rectal toxicity was prioritized. Follow-up was from salvage date to prostate-specific antigen (PSA) concentration failure (Phoenix criteria = nadir + 2.0; ASTRO = 3 consecutive rises), recurrence, distant metastases, or last follow-up PSA level. Progression-free survival (PFS) was defined as no PSA failure or biopsy-proven recurrence without all-cause mortality. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0. Results: At salvage, median age was 68 years, and PSA concentration was 3.5 ng/mL (range, 0.9-5.6 ng/mL). Abnormal MRI/MRS findings were evident in 40% of patients. Biopsy-proven recurrences consisted of a single focus (80%) or 2 foci (20%). At recurrence, Gleason score was 6 (67%) or {>=}7 (27%). Median interval between initial and salvage implantation was 69 months (range, 28-132 months). psPPI planning characteristics limited doses to the rectum (mean V100 = 0.5% [0.07 cc]) and urethra (V100 = 12% [0.3 cc]). At median follow-up (23.3 months; range, 8-88 months), treatment failure (n=2) resulted only in localized recurrence; both patients underwent second psPPI with follow-up PSA tests at 12 and 26 months, resulting in 0.6 and 0.7 ng/mL, respectively. American Society for Radiation Oncology PFS rates at 1, 2, and 3 years were 86.7%, 78.4%, and 62.7%, respectively, with 5 patients for whom treatment failed (n=3 with negative transrectal ultrasound-guided biopsy results). Phoenix PFS rates at 1, 2, and 3 years were 100%, 100%, and 71.4%. 73%, respectively; achieved PSA nadir of <0.5 ng/mL; and 47% of patients had a nadir of <0.1 ng/mL. Treatment-related toxicity was minimal, with no operative interventions, fistulas, or other grade {>=}3 gastrointestinal (GI)/genitourinary (GU) toxicity. Thirteen percent had grade 1 GI and 33% had grade 2 GU toxicities. Postsalvage, 20% of patients had no erectile dysfunction, 67% of patients had medication-responsive erectile dysfunction, and 13% of patients had erectile dysfunction refractory to medication. Conclusions: Focal psPPI with MR-planning in highly selected patients is feasible with short-term control comparable to conventional salvage, with less toxicity. Longer follow-up is needed to confirm its impact on quality of life and treatment.

Hsu, Charles C., E-mail: hsucc@radonc.ucsf.edu [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Hsu, Howard [Department of Radiation Oncology, New York University, New York, New York (United States)] [Department of Radiation Oncology, New York University, New York, New York (United States); Pickett, Barby [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Crehange, Gilles [Department of Radiation Oncology, Dijon University, Dijon (France)] [Department of Radiation Oncology, Dijon University, Dijon (France); Hsu, I-Chow Joe; Dea, Ryan [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Weinberg, Vivian [Biostatistics and Computational Biology Core, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Biostatistics and Computational Biology Core, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Gottschalk, Alexander R. [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Kurhanewicz, John [Department of Radiology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Department of Radiology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Shinohara, Katsuto [Department of Urology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Department of Urology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States); Roach, Mack [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)] [Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California (United States)

2013-02-01T23:59:59.000Z

428

Acoustic resonance frequency locked photoacoustic spectrometer  

DOE Patents [OSTI]

A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell, the acoustic source having a source frequency; repeatedly and continuously sweeping the source frequency across the resonance frequency at a sweep rate; and employing an odd-harmonic of the source frequency sweep rate to maintain the source frequency sweep centered on the resonance frequency.

Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.

2003-09-09T23:59:59.000Z

429

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

430

Nonlinear optics via double dark resonances  

E-Print Network [OSTI]

resonant state, u0&'ud& 1Vc /Vua&, has a small admixture of the excited state, and thus it decays very slowly, which results in a very narrow resonance. In this picture, it is easy to prove that in the all- resonant case, detuning the field Vc by nRF... implies a fre- quency shift of the novel resonance line by nRF . The experiment described in this paper follows a slightly different setup. The states uc& and ud& are degenerate ~i.e., Zeeman sublevels!, whereas the new field, a RF field, has...

Yelin, S. F.; Sautenkov, V. A.; Kash, M. M.; Welch, George R.; Lukin, M. D.

2003-01-01T23:59:59.000Z

431

An electron paramagnetic resonance spectroscopy investigation...  

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

channel is sufficiently small. The results of an electron paramagnetic resonance (EPR) spectroscopy study of Mn and Cu adsorption on the zeolite minerals zeolite Y (large...

432

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...

433

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

434

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

435

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

436

Postpartum Hemorrhage Treated with Gelfoam Slurry Embolization Using the Superselective Technique: Immediate Results and 1-Month MRI Follow-up  

SciTech Connect (OSTI)

To evaluate the efficacy and safety of superselective embolization of the uterine arteries in a postpartum hemorrhage. Between November 2004 and January 2011, a total of 44 consecutive women (median {+-} standard deviation age 34 {+-} 3 years, range 23-41 years) were referred to our institution for postpartum intractable hemorrhage management. All patients were embolized with a microcatheter that was placed deep into the uterine arteries upstream of the cervical arteries. The embolic agent was a mixture of contrast medium and 5 Multiplication-Sign 5 Multiplication-Sign 5 cm pieces of gelfoam (Gelita-Spon) modified into a gelatin emulsion as follows: rapid mixing through a three-way stopcock with two 2.5-ml syringes. A 1-ml syringe was used for injection. One month after embolization, all patients underwent magnetic resonance imaging and clinical examination. Technical and clinical success was obtained in all cases. Thirty-five patients experienced bleeding related to poor retraction of the uterus, 7 patients because of a tear of the cervix and 2 because of a vaginal hematoma. Pre- and postembolization red blood cell transfusions were (mean {+-} standard deviation [SD]) 6 {+-} 1.2 (range 3-8) U and 2 {+-} 0.7 (range 2-4) U, respectively. One-month magnetic resonance imaging follow-up revealed no sign of ischemic myometrium or necrosis, and no instances of uterine rupture and no pelvic vein thrombosis. Incidental findings included two small intramyometrial hematic collections. All uterine arteries were patent via magnetic resonance angiography. Seventeen patients had concomitant fibroids, all of which appeared hypovascular. This technique permits good, safe clinical results with no marked damage to the uterine arteries or the uterus itself.

Pellerin, Olivier, E-mail: olivier.pellerin@egp.aphp.fr [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Interventional Radiology Department (France)] [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Interventional Radiology Department (France); Bats, Anne-Sophie [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Gynecologic and Oncologic Surgery Department (France)] [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Gynecologic and Oncologic Surgery Department (France); Primio, Massimiliano Di; Palomera-Ricco, Ana [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Interventional Radiology Department (France)] [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Interventional Radiology Department (France); Pinot de Villechenon, Gabrielle [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Anesthesia and Surgical Intensive Care Unit (France)] [Universite Paris Descartes, Sorbonne Paris Cite, Faculte de Medecine - Assistance Publique-Hopitaux de Paris - Hopital Europeen Georges-Pompidou, Paris, France, Anesthesia and Surgical Intensive Care Unit (France); and others

2013-02-15T23:59:59.000Z

437

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.

438

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.

439

Diffusing-wave spectroscopy study of microscopic dynamics of three-dimensional granular systems  

E-Print Network [OSTI]

fluidized-granular systems, such as; channel flow, gas-fluidized beds, avalanche flow, and vibro-fluidized, such as magnetic resonance imaging (MRI),21,22 X-ray microtomography,23,24 electrical capacitance tomography (ECT

Pak, Hyuk Kyu

440

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.


441

Electron contamination modeling and skin dose in 6 MV longitudinal field MRIgRT: Impact of the MRI and MRI fringe field  

SciTech Connect (OSTI)

Purpose: In recent times, longitudinal field MRI-linac systems have been proposed for 6 MV MRI-guided radiotherapy (MRIgRT). The magnetic field is parallel with the beam axis and so will alter the transport properties of any electron contamination particles. The purpose of this work is to provide a first investigation into the potential effects of the MR and fringe magnetic fields on the electron contamination as it is transported toward a phantom, in turn, providing an estimate of the expected patient skin dose changes in such a modality. Methods: Geant4 Monte Carlo simulations of a water phantom exposed to a 6 MV x-ray beam were performed. Longitudinal magnetic fields of strengths between 0 and 3 T were applied to a 30 x 30 x 20 cm{sup 3} phantom. Surrounding the phantom there is a region where the magnetic field is at full MRI strength, consistent with clinical MRI systems. Beyond this the fringe magnetic field entering the collimation system is also modeled. The MRI-coil thickness, fringe field properties, and isocentric distance are varied and investigated. Beam field sizes of 5 x 5, 10 x 10, 15 x 15 and 20 x 20 cm{sup 2} were simulated. Central axis dose, 2D virtual entry skin dose films, and 70 {mu}m skin depth doses were calculated using high resolution scoring voxels. Results: In the presence of a longitudinal magnetic field, electron contamination from the linear accelerator is encouraged to travel almost directly toward the patient surface with minimal lateral spread. This results in a concentration of electron contamination within the x-ray beam outline. This concentration is particularly encouraged if the fringe field encompasses the collimation system. Skin dose increases of up to 1000% were observed for certain configurations and increases above Dmax were common. In nonmagnetically shielded cases, electron contamination generated from the jaw faces and air column is trapped and propagated almost directly to the phantom entry region, giving rise to intense dose hot spots inside the x-ray treatment field. These range up to 1000% or more of Dmax at the CAX, depending on field size, isocenter, and coil thickness. In the case of a fully magnetically shielded collimation system and the lowest MRI field of 0.25 T, the entry skin dose is expected to increase to at least 40%, 50%, 65%, and 80% of Dmax for 5 x 5, 10 x 10, 15 x 15, and 20 x 20 cm{sup 2}, respectively. Conclusions: Electron contamination from the linac head and air column may cause considerable skin dose increases or hot spots at the beam central axis on the entry side of a phantom or patient in longitudinal field 6 MV MRIgRT. This depends heavily on the properties of the magnetic fringe field entering the linac beam collimation system. The skin dose increase is also related to the MRI-coil thickness, the fringe field, and the isocenter distance of the linac. The results of this work indicate that the properties of the MRI fringe field, electron contamination production, and transport must be considered carefully during the design stage of a longitudinal MRI-linac system.

Oborn, B. M.; Metcalfe, P. E.; Butson, M. J.; Rosenfeld, A. B.; Keall, P. J. [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500 (Australia) and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500 (Australia) and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Sydney Medical School, University of Sydney, NSW 2006 (Australia)

2012-02-15T23:59:59.000Z

442

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

443

Giant monopole resonance strength in Si-28  

E-Print Network [OSTI]

The giant resonance region in Si-28 was studied with inelastic scattering of 240 MeV alpha particles at small angles including 0 degrees. The giant resonance peak extended from E-x=12 MeV to 35 MeV and E0 strength corresponding to 54 +/- 6...

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

1998-01-01T23:59:59.000Z

444

Unentangling nuclear magnetic resonance Matthias Bechmann 1  

E-Print Network [OSTI]

Unentangling nuclear magnetic resonance computing Matthias Bechmann 1 , John A. Clark 2 , Angelika of York, UK, YO10 5DD Abstract. Nuclear magnetic resonance (NMR) is typically thought of as a possible could be used to perform non-quantum computation: from addressable 3D memory, to a programmable 3D

Stepney, Susan

445

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

446

Method for fabricating a microelectromechanical resonator  

DOE Patents [OSTI]

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

Wojciechowski, Kenneth E; Olsson, III, Roy H

2013-02-05T23:59:59.000Z

447

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

448

Applications of Nuclear Resonance Fluorescence  

SciTech Connect (OSTI)

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

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

2010-11-11T23:59:59.000Z

449

Stochastic resonance for exploration geophysics  

E-Print Network [OSTI]

Stochastic resonance (SR) is a phenomenon in which signal to noise (SN) ratio gets improved by noise addition rather than removal as envisaged classically. SR was first claimed in climatology a few decades ago and then in other disciplines as well. The same as it is observed in natural systems, SR is used also for allowable SN enhancements at will. Here I report a proof of principle that SR can be useful in exploration geophysics. For this I perform high frequency GaussVanicek variance spectral analyses (GVSA) of model traces characterized by varying levels of complexity, completeness and pollution. This demonstration justifies all further research on SR in applied geophysics, as energy demands and depletion of reachable supplies potentially make SR vital in a near future.

Omerbashich, Mensur

2008-01-01T23:59:59.000Z

450

Silicon on Nothing Mems Electromechanical Resonator  

E-Print Network [OSTI]

The very significant growth of the wireless communication industry has spawned tremendous interest in the development of high performances radio frequencies (RF) components. Micro Electro Mechanical Systems (MEMS) are good candidates to allow reconfigurable RF functions such as filters, oscillators or antennas. This paper will focus on the MEMS electromechanical resonators which show interesting performances to replace SAW filters or quartz reference oscillators, allowing smaller integrated functions with lower power consumption. The resonant frequency depends on the material properties, such as Young's modulus and density, and on the movable mechanical structure dimensions (beam length defined by photolithography). Thus, it is possible to obtain multi frequencies resonators on a wafer. The resonator performance (frequency, quality factor) strongly depends on the environment, like moisture or pressure, which imply the need for a vacuum package. This paper will present first resonator mechanisms and mechanical...

Durand, C; Ancey, P; Judong, F; Talbot, A; Quenouillere, R; Renaud, D; Borel, S; Florin, B; Buchaillot, L

2008-01-01T23:59:59.000Z

451

Origin of resonances in chiral dynamics  

E-Print Network [OSTI]

The nature of baryon resonances is studied in the dynamical chiral coupled-channel approach for meson-baryon scattering. In general, origin of resonances in two-body scattering can be classified into two categories: dynamically generated states and genuine elementary particles. We demonstrate that the genuine contribution in the loop function can be excluded by adopting a natural renormalization scheme. The origin of resonances can be studied by looking at the effective interaction in the natural renormalization scheme, which is deduced from the phenomenological amplitude fitted to experimental data. Applying this method to the baryon resonances, we find that the dominant component for the Lambda(1405) resonance is dynamical, while a genuine contribution plays a substantial role for the structure of the N(1535).

Tetsuo Hyodo; Daisuke Jido; Atsushi Hosaka

2009-09-30T23:59:59.000Z

452

Integral data analysis for resonance parameters determination  

SciTech Connect (OSTI)

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

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

1997-09-01T23:59:59.000Z

453

Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material  

SciTech Connect (OSTI)

A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.

Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,

2013-09-03T23:59:59.000Z

454

Nonlinear harmonic generation and devices in doubly resonant Kerr cavities  

E-Print Network [OSTI]

We describe a theoretical analysis of the nonlinear dynamics of third-harmonic generation (??3?) via Kerr (?(3)) nonlinearities in a resonant cavity with resonances at both ? and 3?. Such a doubly resonant cavity greatly ...

Hashemi, Hila

455

Stable Modality-Specific Activity Flows As Reflected by the Neuroenergetic Approach to the fMRI Weighted Maps  

E-Print Network [OSTI]

in the metabolic rate of glucose (PET with FDG) [5]. fMRI measures the consumption of energy by the brain through reflected by the increase of blood flow, blood oxygenation (PET with H2O15 and BOLD fMRI), the increase oxygen consumption, which is needed for the synthesis of the energy-carrying ATP molecules. This energy

Paris-Sud XI, Université de

456

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.

457

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

458

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

459

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...

460

Reliability Tools for Resonance Inspection of Light Metal Castings...  

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

Reliability Tools for Resonance Inspection of Light Metal Castings Reliability Tools for Resonance Inspection of Light Metal Castings 2012 DOE Hydrogen and Fuel Cells Program and...

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

Nuclear Magnetic Resonance Studies on Vanadium(IV) Electrolyte...  

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

Magnetic Resonance Studies on Vanadium(IV) Electrolyte Solutions for Vanadium Redox Flow Battery . Nuclear Magnetic Resonance Studies on Vanadium(IV) Electrolyte Solutions for...

462

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

463

High frequency Pound-Drever-Hall optical ring resonator sensing  

E-Print Network [OSTI]

............................................................................................. 25 Sandia Ring Resonator.................................................................................. 26 Nomadics Little Optics Ring Resonator........................................................ 28 Group Delay..................................................................................................... 29 Laser and Optical Amplification................................................................... 30 5. EXPERIMENTAL SETUP................................................................................. 34 Environmental Test...

Chambers, James Paul

2008-10-10T23:59:59.000Z

464

High frequency Pound-Drever-Hall optical ring resonator sensing  

E-Print Network [OSTI]

............................................................................................. 25 Sandia Ring Resonator.................................................................................. 26 Nomadics Little Optics Ring Resonator........................................................ 28 Group Delay..................................................................................................... 29 Laser and Optical Amplification................................................................... 30 5. EXPERIMENTAL SETUP................................................................................. 34 Environmental Test...

Chambers, James Paul

2009-05-15T23:59:59.000Z

465

acoustic wave resonator: Topics by E-print Network  

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

Helmholtz resonators Physics Websites Summary: Numerical modeling of nonlinear acoustic waves in a tube connected with Helmholtz resonators Bruno Acoustic wave propagation in a...

466

acoustic wave resonators: Topics by E-print Network  

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

Helmholtz resonators Physics Websites Summary: Numerical modeling of nonlinear acoustic waves in a tube connected with Helmholtz resonators Bruno Acoustic wave propagation in a...

467

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

468

Scattering by coupled resonating elements in air  

E-Print Network [OSTI]

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

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

2011-01-12T23:59:59.000Z

469

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

470

New possible resonance for population II Cepheids  

SciTech Connect (OSTI)

Light and velocity curves of some radial mode variable stars seem to indicate a resonance where the second overtone has a period exactly half that of the fundamental mode. The two classes of stars that show this resonance by bumps in their light curves are the classical Cepheids and the population II BL Her variables. We here propose that there is another resonance for the population II W Vir variables where the ratio of the first overtone to the fundamental periods is 0.5.

Cox, A.N.; Kidman, R.B.

1984-01-01T23:59:59.000Z

471

Acoustic resonator and method of making same  

DOE Patents [OSTI]

A method of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers.

Kline, G.R.; Lakin, K.M.

1983-10-13T23:59:59.000Z

472

Acoustic resonator and method of making same  

DOE Patents [OSTI]

A method is disclosed of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers. 4 figs.

Kline, G.R.; Lakin, K.M.

1985-03-05T23:59:59.000Z

473

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

474

Quantum Electrodynamics of Atomic Resonances  

E-Print Network [OSTI]

A simple model of an atom interacting with the quantized electromagnetic field is studied. The atom has a finite mass $m$, finitely many excited states and an electric dipole moment, $\\vec{d}_0 = -\\lambda_{0} \\vec{d}$, where $\\| d^{i}\\| = 1,$ $ i=1,2,3,$ and $\\lambda_0$ is proportional to the elementary electric charge. The interaction of the atom with the radiation field is described with the help of the Ritz Hamiltonian, $-\\vec{d}_0\\cdot \\vec{E}$, where $\\vec{E}$ is the electric field, cut off at large frequencies. A mathematical study of the Lamb shift, the decay channels and the life times of the excited states of the atom is presented. It is rigorously proven that these quantities are analytic functions of the momentum $\\vec{p}$ of the atom and of the coupling constant $\\lambda_0$, provided $|\\vec{p}| < mc$ and $| \\Im\\vec{p} |$ and $| \\lambda_{0} |$ are sufficiently small. The proof relies on a somewhat novel inductive construction involving a sequence of `smooth Feshbach-Schur maps' applied to a complex dilatation of the original Hamiltonian, which yields an algorithm for the calculation of resonance energies that converges super-exponentially fast.

Miguel Ballesteros; Jérémy Faupin; Jürg Fröhlich; Baptiste Schubnel

2015-03-09T23:59:59.000Z

475

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

476

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

477

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

478

Novel 16-Channel Receive Coil Array for Accelerated Upper Airway MRI at 3 Tesla  

E-Print Network [OSTI]

Novel 16-Channel Receive Coil Array for Accelerated Upper Airway MRI at 3 Tesla Yoon-Chul Kim,1 a novel 16-channel 3 Tesla receive coil that is highly sensitive to the human upper airway and investigate on articulatory timing may illuminate the general question of how language-specific knowledge is related to motor

Southern California, University of

479

Voxel-Based MRI Intensitometry Reveals Extent of Cerebral White Matter Pathology in Amyotrophic Lateral  

E-Print Network [OSTI]

Amyotrophic lateral sclerosis (ALS) is characterized by progressive loss of upper and lower motor neurons voxel-based intensitometry (VBI). High resolution T1-weighted MRI was acquired at 1.5 Tesla in 30 ALS neurodegenerative disease characterized by progressive loss of upper motor neurons (UMN) and lower motor neurons

Gaser, Christian

480

MRI-Guided Coronary Catheterization and PTCA: A Feasibility Study on a Dog Model  

E-Print Network [OSTI]

of this work was to demonstrate the feasibility of MRI-guided coronary artery catheterization and intervention- cessful catheterization. Percutaneous transluminal coronary angioplasty (PTCA) was attempted after two of percutaneous transluminal coronary angio- plasty (PTCA) guided by X-ray fluoroscopy has been ex- plosive over

Atalar, Ergin

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481

Efficient Bayesian multivariate fMRI analysis using a sparsifying spatio-temporal prior  

E-Print Network [OSTI]

Efficient Bayesian multivariate fMRI analysis using a sparsifying spatio-temporal prior Marcel A Available online 1 December 2009 Keywords: Multivariate analysis Bayesian inference Expectation propagation Laplace prior is introduced as a multivariate approach to the analysis of neuroimaging data. It is shown

Edinburgh, University of

482

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

483

Author's personal copy Optimal allocation of MRI scan capacity among competing hospital departments  

E-Print Network [OSTI]

an honest forecast of their demands in order to ensure a fair allocation? Various types of MRI scans exist with a demand forecast for the next period. Overestimating demand may be tempting, since it is likely effort into providing a reliable and honest forecast, and do not over- or underestimate their demand. 1

Boucherie, Richard J.

484

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

485

Fractal-driven distortion of resting state functional networks in fMRI: a simulation study  

E-Print Network [OSTI]

Fractal-driven distortion of resting state functional networks in fMRI: a simulation study Wonsang, Magdeburg, Germany E-mail: you@lin-magdeburg.de Fractals are self-similar and scale-invariant patterns found ubiquitously in nature. A lot of evidences implying fractal properties such as 1/f power spectrums have been

486

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

487

The development of MRI for the determination of porosity distribution in reservoir core samples  

E-Print Network [OSTI]

Sandstone appeared to be very isotropic while the Austin Chalk exhibited varying degrees of correlation in the directions considered. A comparison between the correlation of MRI derived core plug size porosity distributions and foot by foot whole core.... . Spatial Correlation of Porosity Data. . . . . . . . . . . . . . . . . . . . . . Comparison with Foot by Foot Vertical Data. . Composite Sample Distribution. . Reproducibility. . 22 , 25 . . . . 30 . . . . . 4 2 . 44 . 47 CHAPTER V ? CONCLUSIONS...

Shivers, Jon Blake

1991-01-01T23:59:59.000Z

488

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

489

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