Sample records for resonance imaging mri

  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. Abstract--Magnetic Resonance Imaging (MRI) guided nanorobotic systems that could perform diagnostic, curative

    E-Print Network [OSTI]

    Mavroidis, Constantinos

    groups have employed magnetized micro/ nanoparticles and have implemented magnetic propulsion techniquesAbstract-- Magnetic Resonance Imaging (MRI) guided nanorobotic systems that could perform on the use of a MRI scanner to induce the required external driving forces to guide magnetic nanocapsules

  3. An Atlas-Based Electron Density Mapping Method for Magnetic Resonance Imaging (MRI)-Alone Treatment Planning and Adaptive MRI-Based Prostate Radiation Therapy

    SciTech Connect (OSTI)

    Dowling, Jason A., E-mail: jason.dowling@csiro.au [Australian e-Health Research Center, CSIRO ICT Commonwealth Scientific and Industrial Research Organisation Information and Communication Technologies Centre, Queensland (Australia); Lambert, Jonathan [Calvary Mater Newcastle Hospital, New South Wales (Australia); University of Newcastle, New South Wales (Australia); Parker, Joel [Calvary Mater Newcastle Hospital, New South Wales (Australia); Salvado, Olivier; Fripp, Jurgen [Australian e-Health Research Center, CSIRO ICT Commonwealth Scientific and Industrial Research Organisation Information and Communication Technologies Centre, Queensland (Australia); Capp, Anne; Wratten, Chris; Denham, James W.; Greer, Peter B. [Calvary Mater Newcastle Hospital, New South Wales (Australia); University of Newcastle, New South Wales (Australia)

    2012-05-01T23:59:59.000Z

    Purpose: Prostate radiation therapy dose planning directly on magnetic resonance imaging (MRI) scans would reduce costs and uncertainties due to multimodality image registration. Adaptive planning using a combined MRI-linear accelerator approach will also require dose calculations to be performed using MRI data. The aim of this work was to develop an atlas-based method to map realistic electron densities to MRI scans for dose calculations and digitally reconstructed radiograph (DRR) generation. Methods and Materials: Whole-pelvis MRI and CT scan data were collected from 39 prostate patients. Scans from 2 patients showed significantly different anatomy from that of the remaining patient population, and these patients were excluded. A whole-pelvis MRI atlas was generated based on the manually delineated MRI scans. In addition, a conjugate electron-density atlas was generated from the coregistered computed tomography (CT)-MRI scans. Pseudo-CT scans for each patient were automatically generated by global and nonrigid registration of the MRI atlas to the patient MRI scan, followed by application of the same transformations to the electron-density atlas. Comparisons were made between organ segmentations by using the Dice similarity coefficient (DSC) and point dose calculations for 26 patients on planning CT and pseudo-CT scans. Results: The agreement between pseudo-CT and planning CT was quantified by differences in the point dose at isocenter and distance to agreement in corresponding voxels. Dose differences were found to be less than 2%. Chi-squared values indicated that the planning CT and pseudo-CT dose distributions were equivalent. No significant differences (p > 0.9) were found between CT and pseudo-CT Hounsfield units for organs of interest. Mean {+-} standard deviation DSC scores for the atlas-based segmentation of the pelvic bones were 0.79 {+-} 0.12, 0.70 {+-} 0.14 for the prostate, 0.64 {+-} 0.16 for the bladder, and 0.63 {+-} 0.16 for the rectum. Conclusions: The electron-density atlas method provides the ability to automatically define organs and map realistic electron densities to MRI scans for radiotherapy dose planning and DRR generation. This method provides the necessary tools for MRI-alone treatment planning and adaptive MRI-based prostate radiation therapy.

  4. Model-based reconstruction of magnetic resonance spectroscopic imaging

    E-Print Network [OSTI]

    Chatnuntawech, Itthi

    2013-01-01T23:59:59.000Z

    Magnetic resonance imaging (MRI) is a medical imaging technique that is used to obtain images of soft tissue throughout the body. Since its development in the 1970s, MRI has gained tremendous importance in clinical practice ...

  5. Simultaneous PET/fMRI for imaging neuroreceptor dynamics

    E-Print Network [OSTI]

    Sander, Christin Y. (Christin Yen-Ming)

    2014-01-01T23:59:59.000Z

    Whole-brain neuroimaging is a key technique for studying brain function and connectivity. Recent advances in combining two imaging modalities - magnetic resonance imaging (MRI) and positron emission tomography (PET) - into ...

  6. Single echo acquisition magnetic resonance imaging 

    E-Print Network [OSTI]

    McDougall, Mary Preston

    2006-04-12T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Lee, Taekwan

    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 ...

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

    E-Print Network [OSTI]

    Lee, Taekwan

    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 ...

  9. Abstract--This study presents a system designed to assist the surgeon during interventional procedures performed by Magnetic Resonance Imaging (MRI). In order to reach the target during guidance in a double obliquity trajectory, this

    E-Print Network [OSTI]

    Boyer, Edmond

    on the instrument are detected [4]. Two commercial solutions have recently appeared on the market: a robotic system of ionizing radiations, Magnetic Resonance Imaging is a well adapted modality for interventional practice. MRI stiff and short, enabling the use of passive detection and/or optical localisation. Passive tracking

  10. Designing and characterizing hyperpolarizable silicon nanoparticles for magnetic resonance imaging

    E-Print Network [OSTI]

    Anahtar, Melis Nuray

    2008-01-01T23:59:59.000Z

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

  11. 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)

    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

    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.

  12. Improvements in magnetic resonance imaging excitation pulse design

    E-Print Network [OSTI]

    Zelinski, Adam Charles

    2008-01-01T23:59:59.000Z

    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) ...

  13. Design algorithms for parallel transmission in magnetic resonance imaging

    E-Print Network [OSTI]

    Setsompop, Kawin

    2008-01-01T23:59:59.000Z

    The focus of this dissertation is on the algorithm design, implementation, and validation of parallel transmission technology in Magnetic Resonance Imaging (MRI). Novel algorithms are proposed which yield excellent excitation ...

  14. RF Pulse Design for Parallel Excitation in Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Liu, Yinan

    2012-07-16T23:59:59.000Z

    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...

  15. 3D RECONSTRUCTION OF PLANT ROOTS FROM MRI IMAGES Hannes Schulz1

    E-Print Network [OSTI]

    Behnke, Sven

    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

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

    E-Print Network [OSTI]

    Behnke, Sven

    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

  17. 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

  18. Reconstruction algorithms for MRI

    E-Print Network [OSTI]

    Bilgic?, Berkin

    2013-01-01T23:59:59.000Z

    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 ...

  19. Respiratory Amplitude Guided 4-Dimensional Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    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

    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.

  20. Improvements in Low Field MRI

    E-Print Network [OSTI]

    Ogier, Stephen E

    2013-02-01T23:59:59.000Z

    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...

  1. A pulsed electromagnet controller for prepolarized MRI

    E-Print Network [OSTI]

    Nam, Hyokwon

    2001-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    By, Samantha

    2014-04-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Lebsack, Eliot Todd

    1999-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Moody, Katherine

    2014-08-11T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

    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 ...

  6. Semi-automatic delineation using weighted CT-MRI registered images for radiotherapy of nasopharyngeal cancer

    SciTech Connect (OSTI)

    Fitton, I. [European Georges Pompidou Hospital, Department of Radiology, 20 rue Leblanc, 75015, Paris (France); Cornelissen, S. A. P. [Image Sciences Institute, UMC, Department of Radiology, P.O. Box 85500, 3508 GA Utrecht (Netherlands); Duppen, J. C.; Rasch, C. R. N.; Herk, M. van [The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Radiotherapy, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Steenbakkers, R. J. H. M. [University Medical Center Groningen, Department of Radiation Oncology, Hanzeplein 1, 9713 GZ Groningen (Netherlands); Peeters, S. T. H. [UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgique (Belgium); Hoebers, F. J. P. [Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO clinic), GROW School for Oncology and Development Biology Maastricht, 6229 ET Maastricht (Netherlands); Kaanders, J. H. A. M. [UMC St-Radboud, Department of Radiotherapy, Geert Grooteplein 32, 6525 GA Nijmegen (Netherlands); Nowak, P. J. C. M. [ERASMUS University Medical Center, Department of Radiation Oncology,Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

    2011-08-15T23:59:59.000Z

    Purpose: To develop a delineation tool that refines physician-drawn contours of the gross tumor volume (GTV) in nasopharynx cancer, using combined pixel value information from x-ray computed tomography (CT) and magnetic resonance imaging (MRI) during delineation. Methods: Operator-guided delineation assisted by a so-called ''snake'' algorithm was applied on weighted CT-MRI registered images. The physician delineates a rough tumor contour that is continuously adjusted by the snake algorithm using the underlying image characteristics. The algorithm was evaluated on five nasopharyngeal cancer patients. Different linear weightings CT and MRI were tested as input for the snake algorithm and compared according to contrast and tumor to noise ratio (TNR). The semi-automatic delineation was compared with manual contouring by seven experienced radiation oncologists. Results: A good compromise for TNR and contrast was obtained by weighing CT twice as strong as MRI. The new algorithm did not notably reduce interobserver variability, it did however, reduce the average delineation time by 6 min per case. Conclusions: The authors developed a user-driven tool for delineation and correction based a snake algorithm and registered weighted CT image and MRI. The algorithm adds morphological information from CT during the delineation on MRI and accelerates the delineation task.

  7. Brain MRI Classification using the Expectation Maximization

    E-Print Network [OSTI]

    Chen, Tsuhan

    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

  8. Wavelet smoothing of fMRI activation images Will Penny,

    E-Print Network [OSTI]

    Penny, Will

    Wavelet smoothing of fMRI activation images Will Penny, Wellcome Department of Imaging Neuroscience methods - such as wavelets. 100 #12;2 Wavelet Transform The wavelet spatial model is that introduced, a wavelet transform is defined in which an N-dimensional image is represented by an N-dimensional image

  9. Can Images Obtained With High Field Strength Magnetic Resonance Imaging Reduce Contouring Variability of the Prostate?

    SciTech Connect (OSTI)

    Usmani, Nawaid, E-mail: Nawaid.Usmani@albertahealthservices.ca [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Department of Oncology, University of Alberta, Edmonton, AB (Canada); Sloboda, Ron [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada); Kamal, Wafa [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Ghosh, Sunita [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Experimental Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Pervez, Nadeem; Pedersen, John; Yee, Don; Danielson, Brita; Murtha, Albert; Amanie, John [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Department of Oncology, University of Alberta, Edmonton, AB (Canada); Monajemi, Tara [Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada)

    2011-07-01T23:59:59.000Z

    Purpose: The objective of this study is to determine whether there is less contouring variability of the prostate using higher-strength magnetic resonance images (MRI) compared with standard MRI and computed tomography (CT). Methods and Materials: Forty patients treated with prostate brachytherapy were accrued to a prospective study that included the acquisition of 1.5-T MR and CT images at specified time points. A subset of 10 patients had additional 3.0-T MR images acquired at the same time as their 1.5-T MR scans. Images from each of these patients were contoured by 5 radiation oncologists, with a random subset of patients repeated to quantify intraobserver contouring variability. To minimize bias in contouring the prostate, the image sets were placed in folders in a random order with all identifiers removed from the images. Results: Although there was less interobserver contouring variability in the overall prostate volumes in 1.5-T MRI compared with 3.0-T MRI (p < 0.01), there was no significant differences in contouring variability in the different regions of the prostate between 1.5-T MRI and 3.0-T MRI. MRI demonstrated significantly less interobserver contouring variability in both 1.5-T and 3.0-T compared with CT in overall prostate volumes (p < 0.01, p = 0.01), with the greatest benefits being appreciated in the base of the prostate. Overall, there was less intraobserver contouring variability than interobserver contouring variability for all of the measurements analyzed. Conclusions: Use of 3.0-T MRI does not demonstrate a significant improvement in contouring variability compared with 1.5-T MRI, although both magnetic strengths demonstrated less contouring variability compared with CT.

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

    E-Print Network [OSTI]

    Arzouni, Nibal

    2012-10-19T23:59:59.000Z

    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...

  11. 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

  12. RF Pulse Design for Parallel Excitation in Magnetic Resonance Imaging 

    E-Print Network [OSTI]

    Liu, Yinan

    2012-07-16T23:59:59.000Z

    , such as accelerating imaging speed, mitigating field inhomogeneity in high-field MRI, and alleviating the susceptibility artifact in functional MRI (fMRI). In these applications, controlling radiofrequency (RF) power deposition (quantified by Specific Absorption Rate...

  13. Low field magnetic resonance imaging

    DOE Patents [OSTI]

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

    2010-07-13T23:59:59.000Z

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

  14. Portable low-cost magnetic resonance imaging

    E-Print Network [OSTI]

    Cooley, Clarissa Zimmerman

    2014-01-01T23:59:59.000Z

    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 ...

  15. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

    SciTech Connect (OSTI)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob, E-mail: ihahn@caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-09-15T23:59:59.000Z

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

  16. Blood-flow magnetic resonance imaging of the retina Yingxia Li,a,1

    E-Print Network [OSTI]

    Duong, Timothy Q.

    Blood-flow magnetic resonance imaging of the retina Yingxia Li,a,1 Haiying Cheng,a,1 and Timothy Q 1 November 2007 This study describes a novel MRI application to image basal blood flow, physiologically induced blood-flow changes, and the effects of isoflurane concentration on blood flow

  17. Instrumentation for parallel magnetic resonance imaging

    E-Print Network [OSTI]

    Brown, David Gerald

    2007-04-25T23:59:59.000Z

    Parallel magnetic resonance (MR) imaging may be used to increase either the throughput or the speed of the MR imaging experiment. As such, parallel imaging may be accomplished either through a "parallelization" of the MR experiment, or by the use...

  18. Flow Imaging Using MRI: Quantification and Analysis

    E-Print Network [OSTI]

    Jiraraksopakun, Yuttapong

    2010-07-14T23:59:59.000Z

    dynamics (CFD) and the conventional optimal flow imaging based on particle image velocimetry (PIV). The results demonstrated the improvement from the quantification using solely the conventional HARP method....

  19. Imaging agents for in vivo magnetic resonance and scintigraphic imaging

    DOE Patents [OSTI]

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

    1991-04-23T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Eyüboðlu, Murat

    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

  1. Design of an MRI compatible robot for wrist rehabilitation

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

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

  2. Surface Plasmon Resonance Imaging Measurements of Electrostatic Biopolymer

    E-Print Network [OSTI]

    Surface Plasmon Resonance Imaging Measurements of Electrostatic Biopolymer Adsorption onto surface plasmon resonance (SPR) imaging experiments is used to charac- terize the differential/RAS) and surface plasmon resonance (SPR) thickness mea- surements. A schematic diagram of the scanning SPR

  3. Challenges for molecular neuroimaging with MRI

    E-Print Network [OSTI]

    Lelyveld, Victor S.

    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 ...

  4. 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

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

    E-Print Network [OSTI]

    Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image of Mathematics, National Taiwan University, Taipei, Taiwan, 4 Elekta Oy, Helsinki, Finland Abstract Ultra-low. (2013) Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image

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

    SciTech Connect (OSTI)

    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

    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.

  7. Magnetic Resonance Pulse Sequences for Fluorine-19

    E-Print Network [OSTI]

    Terry, Robin

    2014-07-11T23:59:59.000Z

    . Magnetic resonance imaging (MRI) has the ability to noninvasively track the transplanted cells to ensure they are in the desired destination. Unlike other MRI contrast agents, fluorine-19 has the ability to provide unambiguous cell tracking for two reasons...

  8. Magnetic resonance imaging of living systems by remote detection

    DOE Patents [OSTI]

    Wemmer, David; Pines, Alexander; Bouchard, Louis; Xu, Shoujun; Harel, Elad; Budker, Dmitry; Lowery, Thomas; Ledbetter, Micah

    2013-10-29T23:59:59.000Z

    A novel approach to magnetic resonance imaging is disclosed. Blood flowing through a living system is prepolarized, and then encoded. The polarization can be achieved using permanent or superconducting magnets. The polarization may be carried out upstream of the region to be encoded or at the place of encoding. In the case of an MRI of a brain, polarization of flowing blood can be effected by placing a magnet over a section of the body such as the heart upstream of the head. Alternatively, polarization and encoding can be effected at the same location. Detection occurs at a remote location, using a separate detection device such as an optical atomic magnetometer, or an inductive Faraday coil. The detector may be placed on the surface of the skin next to a blood vessel such as a jugular vein carrying blood away from the encoded region.

  9. SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

    SciTech Connect (OSTI)

    Moessle, Michael; Hatridge, Michael; Clarke, John

    2006-08-14T23:59:59.000Z

    Magnetic resonance imaging (MRI) has developed into a powerful clinical tool for imaging the human body (1). This technique is based on nuclear magnetic resonance (NMR) of protons (2, 3) in a static magnetic field B{sub 0}. An applied radiofrequency pulse causes the protons to precess about B{sub 0} at their Larmor frequency {nu}{sub 0} = ({gamma}/2{pi})B{sub 0}, where {gamma} is the gyromagnetic ratio; {gamma}/2{pi} = 42.58 MHz/tesla. The precessing protons generate an oscillating magnetic field and hence a voltage in a nearby coil that is amplified and recorded. The application of three-dimensional magnetic field gradients specifies a unique magnetic field and thus an NMR frequency in each voxel of the subject, so that with appropriate encoding of the signals one can acquire a complete image (4). Most clinical MRI systems involve magnetic fields generated by superconducting magnets, and the current trend is to higher magnetic fields than the widely used 1.5-T systems (5). Nonetheless, there is ongoing interest in the development of less expensive imagers operating at lower fields. Commercially available 0.2-T systems based on permanent magnets offer both lower cost and a more open access than their higher-field counterparts, at the expense of signal-to-noise-ratio (SNR) and spatial resolution. At the still lower field of 0.03 mT maintained by a conventional, room-temperature solenoid, Connolly and co-workers (6, 7) obtain good spatial resolution and signal-to-noise ratio (SNR) by prepolarizing the protons in a field B{sub p} of 0.3 T. Prepolarization (8) enhances the magnetic moment of an ensemble of protons over that produced by the lower precession field; after the polarizing field is removed, the higher magnetic moment produces a correspondingly larger signal during its precession in B{sub 0}. Using the same method, Stepisnik et al. (9) obtained MR images in the Earth's magnetic field ({approx} 50 {micro}T). Alternatively, one can enhance the signal amplitude in MRI using laser polarized noble gases such as {sup 3}He or {sup 129}Xe (10-12). Hyperpolarized gases were used successfully to image the human lung in fields on the order of several mT (13-15). To overcome the sensitivity loss of Faraday detection at low frequencies, ultrasensitive magnetometers based on the Superconducting QUantum Interference Device (SQUID) (16) are used to detect NMR and MRI signals (17-24). Recently, SQUID-based MRI systems capable of acquiring in vivo images have appeared. For example, in the 10-mT system of Seton et al. (18) signals are coupled to a SQUID via a superconducting tuned circuit, while Clarke and coworkers (22, 25, 26) developed a system at 132 {micro}T with an untuned input circuit coupled to a SQUID. In a quite different approach, atomic magnetometers have been used recently to detect the magnetization (27) and NMR signal (28) of hyperpolarized gases. This technique could potentially be used for low-field MRI in the future. The goal of this review is to summarize the current state-of-the-art of MRI in microtesla fields detected with SQUIDs. The principles of SQUIDs and NMR are briefly reviewed. We show that very narrow NMR linewidths can be achieved in low magnetic fields that are quite inhomogeneous, with illustrative examples from spectroscopy. After describing our ultralow-field MRI system, we present a variety of images. We demonstrate that in microtesla fields the longitudinal relaxation T{sub 1} is much more material dependent than is the case in high fields; this results in a substantial improvement in 'T{sub 1}-weighted contrast imaging'. After outlining the first attempts to combine microtesla NMR with magnetoencephalography (MEG) (29), we conclude with a discussion of future directions.

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

    SciTech Connect (OSTI)

    Myers, Whittier R.

    2006-05-18T23:59:59.000Z

    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.

  11. Surface Plasmon Resonance Imaging Measurements of Antibody Arrays for the

    E-Print Network [OSTI]

    Surface Plasmon Resonance Imaging Measurements of Antibody Arrays for the Multiplexed Detection molecular weight protein biomarkers with surface plasmon resonance imaging (SPRI). A one methodology would be to use an optical method that can directly detect antigen binding. Surface plasmon

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

    E-Print Network [OSTI]

    Chung, Maranatha

    1993-01-01T23:59:59.000Z

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

  13. MRI Magnetic Signature Imaging, Tracking and Navigation for Targeted Micro/Nano-capsule Therapeutics

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - back for the microdevice and a propulsion sequence to enable interleaved magnetic propulsionMRI Magnetic Signature Imaging, Tracking and Navigation for Targeted Micro J. Nelson, Antoine Ferreira and Sergej Fatikow Abstract-- The propulsion of nano

  14. Classification System for Identifying Women at Risk for Altered Partial Breast Irradiation Recommendations After Breast Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Kowalchik, Kristin V. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); Vallow, Laura A., E-mail: vallow.laura@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); McDonough, Michelle [Department of Radiology, Mayo Clinic, Jacksonville, Florida (United States); Thomas, Colleen S.; Heckman, Michael G. [Section of Biostatistics, Mayo Clinic, Jacksonville, Florida (United States); Peterson, Jennifer L. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); Adkisson, Cameron D. [Department of General Surgery, Mayo Clinic, Jacksonville, Florida (United States); Serago, Christopher [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); McLaughlin, Sarah A. [Department of General Surgery, Mayo Clinic, Jacksonville, Florida (United States)

    2013-09-01T23:59:59.000Z

    Purpose: To study the utility of preoperative breast MRI for partial breast irradiation (PBI) patient selection, using multivariable analysis of significant risk factors to create a classification rule. Methods and Materials: Between 2002 and 2009, 712 women with newly diagnosed breast cancer underwent preoperative bilateral breast MRI at Mayo Clinic Florida. Of this cohort, 566 were retrospectively deemed eligible for PBI according to the National Surgical Adjuvant Breast and Bowel Project Protocol B-39 inclusion criteria using physical examination, mammogram, and/or ultrasound. Magnetic resonance images were then reviewed to determine their impact on patient eligibility. The patient and tumor characteristics were evaluated to determine risk factors for altered PBI eligibility after MRI and to create a classification rule. Results: Of the 566 patients initially eligible for PBI, 141 (25%) were found ineligible because of pathologically proven MRI findings. Magnetic resonance imaging detected additional ipsilateral breast cancer in 118 (21%). Of these, 62 (11%) had more extensive disease than originally noted before MRI, and 64 (11%) had multicentric disease. Contralateral breast cancer was detected in 28 (5%). Four characteristics were found to be significantly associated with PBI ineligibility after MRI on multivariable analysis: premenopausal status (P=.021), detection by palpation (P<.001), first-degree relative with a history of breast cancer (P=.033), and lobular histology (P=.002). Risk factors were assigned a score of 0-2. The risk of altered PBI eligibility from MRI based on number of risk factors was 0:18%; 1:22%; 2:42%; 3:65%. Conclusions: Preoperative bilateral breast MRI altered the PBI recommendations for 25% of women. Women who may undergo PBI should be considered for breast MRI, especially those with lobular histology or with 2 or more of the following risk factors: premenopausal, detection by palpation, and first-degree relative with a history of breast cancer.

  15. Investigation of PET/MRI Image Fusion Schemes for Enhanced Breast Cancer Diagnosis

    E-Print Network [OSTI]

    with anatomical images is well appreciated in the advent of PET/CT. There is an increasing interest in expanding. Initial experience with combined PET (functional imaging) and x-ray computed tomography (CT, anatomicalInvestigation of PET/MRI Image Fusion Schemes for Enhanced Breast Cancer Diagnosis Karl G. Baum

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

    E-Print Network [OSTI]

    Ekstrom, Leeland Bruce

    2009-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Bosshard, John

    2006-08-16T23:59:59.000Z

    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...

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

    DOE Patents [OSTI]

    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

    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.

  19. Modeling Left Ventricle Wall Motion Using Tagged Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Alenezy, Mohammed D.

    2009-04-17T23:59:59.000Z

    can be calculated as M = ?nullN 2 tanh( ?nullB 0 2kT ) (2.3) In a biological sample that contains about 1mL of water, there are about 10 22 hydrogen nuclei, and at the room... population that is frequently in need of quality tomographic images for the assessment of congenital heart defects. MRI can characterize myocardial function through the use of cine MRI and tagged MRI. The latter provides a means to assess wall motion...

  20. Magnetic resonance imaging of self-assembled biomaterial scaffolds

    SciTech Connect (OSTI)

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

    2014-09-16T23:59:59.000Z

    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.

  1. Nanoscale magnetic resonance imaging C. L. Degena

    E-Print Network [OSTI]

    Leonardo, Degiorgi

    tobacco mosaic virus particles sitting on a nanometer-thick layer of ad- sorbed hydrocarbons. This result, which represents a 100 million- fold improvement in volume resolution over conventional MRI considerable effort, attempts to push the spatial resolution of conventional MRI into the realm of high

  2. Magnetic resonance spectroscopic imaging using parallel transmission at 7T

    E-Print Network [OSTI]

    Gagoski, Borjan Aleksandar

    2011-01-01T23:59:59.000Z

    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 ...

  3. Coil performance evaluation based on electrodynamics : tools for hardware design and validation in magnetic resonance imaging

    E-Print Network [OSTI]

    Lattanzi, Riccardo

    2008-01-01T23:59:59.000Z

    Parallel MRI techniques allow acceleration of MR imaging beyond traditional speed limits. In parallel MRI, radiofrequency (RF) detector coil arrays are used to perform some degree of spatial encoding which complements ...

  4. 1248 IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 53, NO. 3, JUNE 2006 Aligning Emission Tomography and MRI Images

    E-Print Network [OSTI]

    . These methods depend on accurate registration of PET/SPECT and MRI/CT images. Herein, we consider registration using PET/SPECT projec- tion data only. Index Terms--CT, image reconstruction, MRI, PET, registra- tion, Fellow, IEEE Abstract--An important approach to reconstructing PET and SPECT (PET/SPECT) radiotracer

  5. Long-Range Surface Plasmon Resonance Imaging for Bioaffinity Sensors

    E-Print Network [OSTI]

    Long-Range Surface Plasmon Resonance Imaging for Bioaffinity Sensors Alastair W. Wark, Hye Jin Lee A novel bioaffinity sensor based on surface plasmon resonance (SPR) imaging measurements of a multiple- layered structure that supports the generation of long- range surface plasmons (LRSPs) at the water

  6. 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)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  8. 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)

    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

    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.

  9. FY08 Annual Report for Nuclear Resonance Fluorescence Imaging

    SciTech Connect (OSTI)

    Warren, Glen A.; Caggiano, Joseph A.

    2009-01-06T23:59:59.000Z

    FY08 annual report for project the "Nuclear Resonance Fluorescence Imaging" project. Reviews accomplishments of last 3 years, including U-235 signature search, comparison of different photon sources, and examination of NRF measurements using monochromatic photon source.

  10. Automatic Tissue Classification for the Human Head from Multispectral MRI

    E-Print Network [OSTI]

    Utah, University of

    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

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  13. Surface-Based Analysis of Functional Magnetic Resonance Imaging Data

    E-Print Network [OSTI]

    Thompson, Paul

    Surface-Based Analysis of Functional Magnetic Resonance Imaging Data Theo G.M. van Erp1, Vikas Y School of Medicine, Los Angeles, CA 90095, USA Abstract. Surface-based visualization, atlases the integration of surface-based tech- niques with functional imaging data, combining surface-based nonlinear

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

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01T23:59:59.000Z

    The primary design criterion for RF transmit coils for MRI is uniform transverse magnetic (B1) field. Currently, most high frequency transmit coils are designed as periodic, symmetric structures that are resonant at the ...

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

    SciTech Connect (OSTI)

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

    2012-11-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    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

    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.

  17. Method for nuclear magnetic resonance imaging

    DOE Patents [OSTI]

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

    1988-05-26T23:59:59.000Z

    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.

  18. He Lung Imaging in an Open Access, Very-Low-Field Human Magnetic Resonance Imaging System

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    3 He Lung Imaging in an Open Access, Very-Low-Field Human Magnetic Resonance Imaging System R. W. Butler,6 F. W. Hersman,4 and R. L. Walsworth1 The human lung and its functions are extremely sensitive lung restrict sub- jects to lying horizontally. Imaging of human lungs using inhaled laser-polarized 3

  19. A numerical approach : broadband technologies for efficient Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Mitsouras, Dimitrios, 1976-

    2004-01-01T23:59:59.000Z

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

  20. Parallel magnetic resonance imaging: characterization and comparison

    E-Print Network [OSTI]

    Rane, Swati Dnyandeo

    2005-11-01T23:59:59.000Z

    [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...

  1. Numerical field simulation for parallel transmission in MRI at 7 tesla

    E-Print Network [OSTI]

    Bernier, Jessica A. (Jessica Ashley)

    2011-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Sander, Christin Yen-Ming

    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 ...

  3. Solutions to various problems in reversible cooling fMRI studies

    E-Print Network [OSTI]

    Khachaturian, Mark Haig, 1979-

    2003-01-01T23:59:59.000Z

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

  4. Predictive models of tissue outcome in acute human cerebral ischemia using diffusion and perfusion weighted MRI

    E-Print Network [OSTI]

    Wu, Ona

    2002-01-01T23:59:59.000Z

    Diffusion (DWI) and perfusion weighted (PWI) magnetic resonance imaging (MRI) provide significant insight into acute stroke and can potentially be useful for clinical decision-making. In particular, current therapeutic ...

  5. Original Research Magnetic Resonance Image-Guided Trans-Septal

    E-Print Network [OSTI]

    Atalar, Ergin

    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

  6. Blood Flow Magnetic Resonance Imaging of Retinal Degeneration

    E-Print Network [OSTI]

    Duong, Timothy Q.

    Blood Flow Magnetic Resonance Imaging of Retinal Degeneration Yingxia Li,1 Haiying Cheng,1 Qiang. Duong1,2,3,4,5,6,7 PURPOSE. This study aims to investigate quantitative basal blood flow as well as hypercapnia- and hyperoxia-induced blood flow changes in the retinas of the Royal College of Surgeons (RCS

  7. Magnetic Resonance Imaging System Based on Earth's Magnetic Field

    E-Print Network [OSTI]

    Stepi?nik, Janez

    Magnetic Resonance Imaging System Based on Earth's Magnetic Field Ales Mohoric,1,* Gorazd Planinsic magnetic field can be partly compensated by the receiving coil design and shielding of electromagnetic pick and must be monitored accurately.[8­ 10] The importance of NMR in a non-uniform magnetic field

  8. An analysis of the PERL Magnetic Resonance Imaging theory and implementation

    E-Print Network [OSTI]

    Kremkus, Mark Christian

    2013-02-22T23:59:59.000Z

    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...

  9. 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]

    Southern California, University of

    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

  10. SU-E-J-144: MRI Visualization of a Metallic Fiducial Marker Used for Image Guided Prostate Radiotherapy

    SciTech Connect (OSTI)

    Yee, S; Krauss, D; Yan, D [William Beaumont Hospital, Royal Oak, MI (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Unlike on the daily CBCT used for the image-guided radiation therapy, the visualization of an implantable metallic fiducial marker on the planning MRI images has been a challenge due to the inherent insensitivity of metal in MRI, and very thin (? 1 mm or less) diameter. Here, an MRI technique to visualize a marker used for prostate cancer radiotherapy is reported. Methods: During the MRI acquisitions, a multi-shot turbo spin echo (TSE) technique (TR=3500 ms, TE=8.6 ms, ETL=17, recon voxel=0.42x0.42x3.5 mm3) was acquired in Philips 3T Ingenia together with a T2-weighted multi-shot TSE (TR=5381 ms, TE=110 ms, ETL=17, recon voxel=0.47×0.47×3 mm3) and a balanced turbo field echo (bTFE, flip angle 60, TR=2.76 ms, TE=1.3 ms, 0.85×0.85×3 mm3, NSA=4). In acquiring the MRI to visualize the fiducial marker, a particular emphasis was made to improve the spatial resolution and visibility in the generally dark, inhomogeneous prostate area by adjusting the slice profile ordering and TE values of TSE acquisition (in general, the lower value of TE in TSE acquisition generates a brighter signal but at the cost of high spatial resolution since the k-space, responsible for high spatial resolution, is filled with noisier data). Results: While clearly visible in CT, the marker was not visible in either T2-weighted TSE or bTFE, although the image qualities of both images were superior. In the new TSE acquisition (? a proton-density weighted image) adjusted by changing the profile ordering and the TE value, the marker was visible as a negative (but clear) contrast in the magnitude MRI, and as a positive contrast in the imaginary image of the phase-sensitive MRI. Conclusion: A metallic fiducial marker used for image guidance before prostate cancer radiotherapy can be made visible in MRI, which may facilitate more use of MRI in planning and guiding such radiation therapy.

  11. Application of Parallel Imaging to Murine Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Chang, Chieh-Wei 1980-

    2012-09-21T23:59:59.000Z

    . 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...

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

    E-Print Network [OSTI]

    Zakszewski, Elizabeth K

    2006-01-01T23:59:59.000Z

    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 ...

  13. Haptic System Design for MRI-Guided Needle Based Prostate Brachytherapy

    E-Print Network [OSTI]

    Camesano, Terri

    Gregory A. Cole Kevin Harrington Gregory S. Fischer ABSTRACT This paper presents the design of a hapticHaptic System Design for MRI-Guided Needle Based Prostate Brachytherapy Hao Su Weijian Shang system for prostate nee- dle brachytherapy under magnetic resonance imaging (MRI) guid- ance. This haptic

  14. Development of integrated imaging techniques for investigating biomarkers in glioblastoma

    E-Print Network [OSTI]

    Kim, Heisoog

    2011-01-01T23:59:59.000Z

    Cancer is a diverse disease with many manifestations. Various imaging modalities including magnetic resonance imaging (MRI) and positron emission tomography (PET) have been used to study human cancer. In this study, we ...

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

    E-Print Network [OSTI]

    Withers, James

    2010-01-01T23:59:59.000Z

    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 ...

  16. Advances in Surface Plasmon Resonance Imaging Enable Quantitative Tracking of Nanoscale Changes in Thickness and

    E-Print Network [OSTI]

    Dutcher, John

    Advances in Surface Plasmon Resonance Imaging Enable Quantitative Tracking of Nanoscale Changes: To date, detailed studies of the thickness of coatings using surface plasmon resonance have been limited a significant improvement to surface plasmon resonance imaging (SPRi) that allows this sensitive technique

  17. Magnetic resonance visualization of conductive structures by sequence-triggered direct currents and spin-echo phase imaging

    SciTech Connect (OSTI)

    Eibofner, Frank; Wojtczyk, Hanne; Graf, Hansjörg, E-mail: hansjoerg.graf@med.uni-tuebingen.de, E-mail: drGraf@t-online.de [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)] [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany); Clasen, Stephan [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)] [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)

    2014-06-15T23:59:59.000Z

    Purpose: Instrument visualization in interventional magnetic resonance imaging (MRI) is commonly performed via susceptibility artifacts. Unfortunately, this approach suffers from limited conspicuity in inhomogeneous tissue and disturbed spatial encoding. Also, susceptibility artifacts are controllable only by sequence parameters. This work presents the basics of a new visualization method overcoming such problems by applying sequence-triggered direct current (DC) pulses in spin-echo (SE) imaging. SE phase images allow for background free current path localization. Methods: Application of a sequence-triggered DC pulse in SE imaging, e.g., during a time period between radiofrequency excitation and refocusing, results in transient field inhomogeneities. Dependent on the additional z-magnetic field from the DC, a phase offset results despite the refocusing pulse. False spatial encoding is avoided by DC application during periods when read-out or slice-encoding gradients are inactive. A water phantom containing a brass conductor (water equivalent susceptibility) and a titanium needle (serving as susceptibility source) was used to demonstrate the feasibility. Artifact dependence on current strength and orientation was examined. Results: Without DC, the brass conductor was only visible due to its water displacement. The titanium needle showed typical susceptibility artifacts. Applying triggered DC pulses, the phase offset of spins near the conductor appeared. Because SE phase images are homogenous also in regions of persistent field inhomogeneities, the position of the conductor could be determined with high reliability. Artifact characteristic could be easily controlled by amperage leaving sequence parameters unchanged. For an angle of 30° between current and static field visualization was still possible. Conclusions: SE phase images display the position of a conductor carrying pulsed DC free from artifacts caused by persistent field inhomogeneities. Magnitude and phase images are acquired simultaneously under the same conditions without the use of extra measurement time. The presented technique offers many advantages for precise instrument localization in interventional MRI.

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

    SciTech Connect (OSTI)

    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

    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.

  19. Ultra-fast Imaging of Two-Phase Flow in Structured Monolith Reactors; Techniques and Data Analysis

    E-Print Network [OSTI]

    Heras, Jonathan Jaime

    This thesis will address the use of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) techniques to probe the “monolith reactor”, which consists of a structured catalyst over which reactions may occur. This reactor has emerged...

  20. Magnetic Resonance Imaging of Acute Reperfused Myocardial Infarction: Intraindividual Comparison of ECIII-60 and Gd-DTPA in a Swine Model

    SciTech Connect (OSTI)

    Jin Jiyang; Teng Gaojun [Zhongda Hospital of Southeast University, Department of Radiology (China); Feng Yi; Wu Yanping [Zhongda Hospital of Southeast University, Department of Cardiology (China); Jin Qindi [Zhongda Hospital of Southeast University, Department of Radiology (China); Wang Yu [Zhongda Hospital of Southeast University, Department of Cardiology (China); Wang Zhen [Zhongda Hospital of Southeast University, Department of Anaesthesiology (China); Lu Qin [Zhongda Hospital of Southeast University, Department of Radiology (China); Jiang Yibo [Zhongda Hospital of Southeast University, Department of Cardiology (China); Wang Shengqi; Chen Feng [Zhongda Hospital of Southeast University, Department of Radiology (China); Marchal, Guy; Ni Yicheng [University Hospitals, University of Leuven, Department of Radiology (Belgium)], E-mail: yicheng.ni@med.kuleuven.ac.be

    2007-04-15T23:59:59.000Z

    Purpose. To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI). Methods. Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining. Results. A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80x smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining. Conclusion. Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.

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

    E-Print Network [OSTI]

    Black, Ashley Anne

    2007-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

  3. UNSUPERVISED SEGMENTATION FOR AUTOMATIC DETECTION OF BRAIN TUMORS IN MRI

    E-Print Network [OSTI]

    Lefèvre, Sébastien

    a pre-segmentation to ex- tract the brain from the head. Then, a second segmentation is done insideUNSUPERVISED 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

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

    E-Print Network [OSTI]

    Neumaier, Arnold

    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

  5. Portable MRI

    SciTech Connect (OSTI)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29T23:59:59.000Z

    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.

  6. Approaches to Creating and Controlling Motion in MRI Gregory S. Fischer, Member, IEEE, Gregory Cole, Student Member, IEEE and Hao Su, Student Member, IEEE

    E-Print Network [OSTI]

    Camesano, Terri

    Approaches to Creating and Controlling Motion in MRI Gregory S. Fischer, Member, IEEE, Gregory Cole, Student Member, IEEE and Hao Su, Student Member, IEEE Abstract-- Magnetic Resonance Imaging (MRI) can is complicated by factors including: the high magnetic field strength, the requirement that such devices should

  7. 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]

    Burgoyne, Chris

    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

  8. Distortion-free magnetic resonance imaging in the zero-field limit

    SciTech Connect (OSTI)

    Kelso, Nathan; Lee, Seung-Kyun; Bouchard, Louis-S.; Demas, Vasiliki; Muck, Michael; Pines, Alexander; Clarke, John

    2009-07-09T23:59:59.000Z

    MRI is a powerful technique for clinical diagnosis and materials characterization. Images are acquired in a homogeneous static magnetic field much higher than the fields generated across the field of view by the spatially encoding field gradients. Without such a high field, the concomitant components of the field gradient dictated by Maxwell's equations lead to severe distortions that make imaging impossible with conventional MRI encoding. In this paper, we present a distortion-free image of a phantom acquired with a fundamentally different methodology in which the applied static field approaches zero. Our technique involves encoding with pulses of uniform and gradient field, and acquiring the magnetic field signals with a SQUID. The method can be extended to weak ambient fields, potentially enabling imaging in the Earth's field without cancellation coils or shielding. Other potential applications include quantum information processing and fundamental studies of long-range ferromagnetic interactions.

  9. A practical acceleration algorithm for real-time imaging

    E-Print Network [OSTI]

    Sumbul, Uygar

    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 ...

  10. High-Grade Glioma Radiation Therapy Target Volumes and Patterns of Failure Obtained From Magnetic Resonance Imaging and {sup 18}F-FDOPA Positron Emission Tomography Delineations From Multiple Observers

    SciTech Connect (OSTI)

    Kosztyla, Robert, E-mail: rkosztyla@bccancer.bc.ca [Department of Medical Physics, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Chan, Elisa K.; Hsu, Fred [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Wilson, Don [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Functional Imaging, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Ma, Roy; Cheung, Arthur [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Zhang, Susan [Department of Medical Physics, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Functional Imaging, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Moiseenko, Vitali [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California (United States); Benard, Francois [Department of Functional Imaging, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Nichol, Alan [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada)

    2013-12-01T23:59:59.000Z

    Purpose: The objective of this study was to compare recurrent tumor locations after radiation therapy with pretreatment delineations of high-grade gliomas from magnetic resonance imaging (MRI) and 3,4-dihydroxy-6-[{sup 18}F]fluoro-L-phenylalanine ({sup 18}F-FDOPA) positron emission tomography (PET) using contours delineated by multiple observers. Methods and Materials: Nineteen patients with newly diagnosed high-grade gliomas underwent computed tomography (CT), gadolinium contrast-enhanced MRI, and {sup 18}F-FDOPA PET/CT. The image sets (CT, MRI, and PET/CT) were registered, and 5 observers contoured gross tumor volumes (GTVs) using MRI and PET. Consensus contours were obtained by simultaneous truth and performance level estimation (STAPLE). Interobserver variability was quantified by the percentage of volume overlap. Recurrent tumor locations after radiation therapy were contoured by each observer using CT or MRI. Consensus recurrence contours were obtained with STAPLE. Results: The mean interobserver volume overlap for PET GTVs (42% ± 22%) and MRI GTVs (41% ± 22%) was not significantly different (P=.67). The mean consensus volume was significantly larger for PET GTVs (58.6 ± 52.4 cm{sup 3}) than for MRI GTVs (30.8 ± 26.0 cm{sup 3}, P=.003). More than 95% of the consensus recurrence volume was within the 95% isodose surface for 11 of 12 (92%) cases with recurrent tumor imaging. Ten (91%) of these cases extended beyond the PET GTV, and 9 (82%) were contained within a 2-cm margin on the MRI GTV. One recurrence (8%) was located outside the 95% isodose surface. Conclusions: High-grade glioma contours obtained with {sup 18}F-FDOPA PET had similar interobserver agreement to volumes obtained with MRI. Although PET-based consensus target volumes were larger than MRI-based volumes, treatment planning using PET-based volumes may not have yielded better treatment outcomes, given that all but 1 recurrence extended beyond the PET GTV and most were contained by a 2-cm margin on the MRI GTV.

  11. 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]

    Duncan, James S.

    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

  12. 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

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

    E-Print Network [OSTI]

    Gollub, Randy L.

    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 ...

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

    E-Print Network [OSTI]

    Van Hyfte, John Bruce

    1997-01-01T23:59:59.000Z

    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...

  15. Surface Plasmon Resonance Imaging Using a High Numerical Aperture Microscope Objective

    E-Print Network [OSTI]

    Zare, Richard N.

    Surface Plasmon Resonance Imaging Using a High Numerical Aperture Microscope Objective Bo Huang-5080 We designed, constructed, and tested a surface plasmon resonance (SPR) microscope using a high, combined with various methods to shorten the surface plasmon propaga- tion length, achieves diffraction

  16. Quantitative Clinical Evaluation of a Simultaneous PETI MRI Breast Imaging System

    SciTech Connect (OSTI)

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

    2013-04-03T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Kischell, Eric Robert

    1993-01-01T23:59:59.000Z

    ' (Member) A. D. Patton ( ead of epartment) August 1993 Major Subject: Electrical Engineering ABSTRACT Classification of Brain Compartments and Head Injury Lesions by Neural Networks Applied to Magnetic Resonance Images. (August 1993) Eric Robert... Kischell, B. S. , Northeastern University Chair of Advisory Committee: Dr. Nasser Kehtarnavaz An automatic neural network-based approach was ap- plied to segment brain compartments and closed-head-injury lesions in magnetic resonance (MR) images Two...

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

    E-Print Network [OSTI]

    Sherman, Byron Blake

    1991-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Mandava, Shanthi Sree

    1991-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    1910-30-72T23:59:59.000Z

    The two types of images are then compared; the regions where there are significant ... techniques at various stages in the production of the magnitude images.

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

    SciTech Connect (OSTI)

    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

    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.

  2. Surface Plasmon Resonance of Nanoparticles and Applications in Imaging

    E-Print Network [OSTI]

    Habib Ammari; Youjun Deng; Pierre Millien

    2014-12-11T23:59:59.000Z

    In this paper we provide a mathematical framework for localized plasmon resonance of nanoparticles. Using layer potential techniques associated with the full Maxwell equations, we derive small-volume expansions for the electromagnetic fields, which are uniformly valid with respect to the nanoparticle's bulk electron relaxation rate. Then, we discuss the scattering and absorption enhancements by plasmon resonant nanoparticles. We study both the cases of a single and multiple nanoparticles. We present numerical simulations of the localized surface plasmonic resonances associated to multiple particles in terms of their separation distance.

  3. Abstract--Magnetic Resonance Imaging (MRI) guided prostate biopsy and brachytherapy has been introduced in

    E-Print Network [OSTI]

    Camesano, Terri

    is a major health concern in the United States. In 2009, an estimate of 192280 new cases and 27360 deaths%) for men. In the last two decades, however, the death rate is decreasing, which largely reflects are reported, which are the largest number of male cancer (25%) and the second largest cause of cancer death (9

  4. Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

    SciTech Connect (OSTI)

    Bloch, B. Nicolas [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria)], E-mail: nbloch@bidmc.harvard.edu; Lenkinski, Robert E. [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Helbich, Thomas H. [Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria); Ngo, Long [Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Oismueller, Renee [Institute for Radio-Oncology, Danube Hospital, Vienna (Austria); Jaromi, Silvia; Kubin, Klaus [Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria); Hawliczek, Robert [Institute for Radio-Oncology, Danube Hospital, Vienna (Austria); Kaplan, Irving D. [Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Rofsky, Neil M. [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States)

    2007-09-01T23:59:59.000Z

    Purpose: To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations. Methods and Materials: Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of data read by both readers for a specific subject was assessed with a linear mixed effects model. Results: The mean percentage ({+-} standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% {+-} 4.8%, 78.5% {+-} 8.5%, and 96.1% {+-} 2.3%, respectively, with 11.8% {+-} 4.5%, 8.5% {+-} 3.5%, 1.9% {+-} 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% {+-} 1.6% and 2.1% {+-} 0.9%; seminal vesicles, 0.9% {+-} 1.8% and 0.3% {+-} 0.7%; periurethral, 7.1% {+-} 3.3% and 5.8% {+-} 2.9%; penile bulb, 0.6% {+-} 0.8% and 0.3% {+-} 0.6%; Denonvillier's Fascia/rectal wall, 0.5% {+-} 0.6% and 0%; and urinary bladder, 0.1% {+-} 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification. Conclusion: Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.

  5. SLIDING MODE CONTROL OF PIEZOELECTRIC VALVE REGULATED PNEUMATIC ACTUATOR FOR MRI-COMPATIBLE ROBOTIC INTERVENTION

    E-Print Network [OSTI]

    Camesano, Terri

    @wpi.edu ABSTRACT This paper presents the design of a magnetic resonance imaging (MRI) compatible pneumatic actuator@wpi.edu Gregory S. Fischer Mechanical Engineering Worcester Polytechnic Institute Worcester, MA 01609 gfischer provides high-fidelity soft tissue contrast and high spatial resolution. However, the high- field magnetic

  6. MRI-based Microrobotic system for the Propulsion and Navigation of Ferromagnetic Microcapsules

    E-Print Network [OSTI]

    Boyer, Edmond

    MRI-based Microrobotic system for the Propulsion and Navigation of Ferromagnetic Microcapsules 3-D navigation of a microdevice in blood ves- sels, namely: (i) vessel path planner, (ii) magnetic, magnetic resonance imaging, minimally invasive interventions, real-time control Email address: antoine

  7. COMPUTATIONAL STUDIES OF CONTROLLED NANOPARTICLE AGGLOMERATIONS FOR MRI-GUIDED NANOROBOTIC DRUG-DELIVERY SYSTEMS

    E-Print Network [OSTI]

    Mavroidis, Constantinos

    groups have employed magnetized micro/ nanoparticles and have implemented magnetic propulsion techniques implementation is difficult and medically invasive. Finally, magnetic propulsion techniques #12;other thanEastern University Boston, MA 02115 mavro@coe.neu.edu ABSTRACT Magnetic Resonance Imaging (MRI) guided nanorobotic

  8. The neural correlates of statistical learning in a word segmentation task: An fMRI study

    E-Print Network [OSTI]

    Aslin, Richard N.

    language Sequence learning Broca's area LIFG a b s t r a c t Functional magnetic resonance imaging (f of this statistical learning mechanism in the do- main of language acquisition (see also Saffran, Aslin, & NewportThe neural correlates of statistical learning in a word segmentation task: An fMRI study Elisabeth

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

    DOE Patents [OSTI]

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  11. Microfluidically Cryo-Cooled Planar Coils for Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Koo, Chiwan

    2013-08-09T23:59:59.000Z

    is approximately the same as the diameters of the microcoils. Here microfluidic technology is utilized to locally cryo-cool the microcoils and minimize the thermal isolation gap so that the imaging surface is within the imaging depth of the microcoils. The first...

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

    E-Print Network [OSTI]

    Ciesielski, Krzysztof Chris

    . Campbell3 1 Medical Image Processing Group, Department of Radiology, University of Pennsylvania for constructing the best possible 4D scene from such data entirely in the digital domain. Our proposed method of the thorax. 4D-CT involves additional radiation dose over and above the level associated with static imaging

  13. Simultaneous Electroencephalography and Functional Magnetic Resonance Imaging of General Anesthesia

    E-Print Network [OSTI]

    Purdon, Patrick Lee

    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 ...

  14. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Schumann, Heidrun

    A REAL TIME 3D VISUALIZATION PROTOTYPE FOR INTERVENTIONAL MAGNETIC RESONANCE IMAGING JENS FISCHER­invasive examinations. This prototype allows simultaneous visualization of three different types of data: a 3D­Magnetic@informatik.uni­rostock.de Abstract: This paper describes a prototype of a visualization system which is designed to support

  16. Fast and contrast-enhanced phase-sensitive magnetic resonance imaging

    E-Print Network [OSTI]

    Son, Jong Bum

    2009-05-15T23:59:59.000Z

    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...

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

    DOE Patents [OSTI]

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

    2014-01-21T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    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

    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.

  19. GPU-accelerated denoising of 3D magnetic resonance images

    SciTech Connect (OSTI)

    Howison, Mark; Wes Bethel, E.

    2014-05-29T23:59:59.000Z

    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.

  20. Combined PET/MRI scanner

    DOE Patents [OSTI]

    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

    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.

  1. Nuclear magnetic resonance imaging of water content in the subsurface

    SciTech Connect (OSTI)

    J. Hendricks; T. Yao; A. Kearns

    1999-01-21T23:59:59.000Z

    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.

  2. Technical Note Intracoronary MR Imaging Using a 0.014-Inch MR

    E-Print Network [OSTI]

    Atalar, Ergin

    -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

  3. Potential Applications of Microtesla Magnetic Resonance Imaging Detected Using a Superconducting Quantum Interference Device

    E-Print Network [OSTI]

    Myers, Whittier R.

    2006-01-01T23:59:59.000Z

    MRI system were wound on wooden coil forms. Figure 1.12copper wire wound on wooden coil forms. As in the first-MRI system. We wound these coils on a two circular forms cut

  4. Single-Shot Magnetic Resonance Spectroscopic Imaging with Partial Parallel Imaging

    E-Print Network [OSTI]

    spectroscopic imaging (MRSI) pulse se- quence based on proton­echo-planar-spectroscopic-imaging (PEPSI. Comparison with conventional PEPSI and PEPSI with fourfold SENSE accelera- tion demonstrated comparable-acetyl-aspartate (NAA) in vivo with concentration values in the ranges measured with conventional PEPSI and SENSE

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

    SciTech Connect (OSTI)

    Goodson, Boyd M.

    1999-12-01T23:59:59.000Z

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

  6. Assessment of cartilage-dedicated sequences at ultra-high-field MRI: comparison of imaging performance and diagnostic confidence between 3.0 and 7.0 T with respect to osteoarthritis-induced changes at the knee joint

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    OA)-induced changes at 7.0 and 3.0 T MRI. Materialsfor cartilage imaging at 3.0 T were tailored for 7.0 T: anM, Tanenbaum L, Crues JV 3rd. 3.0 Tesla imaging of the

  7. A dual model HU conversion from MRI intensity values within and outside of bone segment for MRI-based radiotherapy treatment planning of prostate cancer

    SciTech Connect (OSTI)

    Korhonen, Juha, E-mail: juha.p.korhonen@hus.fi [Clinical Research Institute Helsinki University Central Hospital Ltd., POB-700, 00029 HUS (Finland) [Clinical Research Institute Helsinki University Central Hospital Ltd., POB-700, 00029 HUS (Finland); Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland); Kapanen, Mika [Clinical Research Institute Helsinki University Central Hospital Ltd., POB-700, 00029 HUS (Finland) [Clinical Research Institute Helsinki University Central Hospital Ltd., POB-700, 00029 HUS (Finland); Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland); Department of Medical Physics, Tampere University Hospital, POB-2000, 33521 Tampere (Finland); Keyriläinen, Jani; Seppälä, Tiina; Tenhunen, Mikko [Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland)] [Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland)

    2014-01-15T23:59:59.000Z

    Purpose: The lack of electron density information in magnetic resonance images (MRI) poses a major challenge for MRI-based radiotherapy treatment planning (RTP). In this study the authors convert MRI intensity values into Hounsfield units (HUs) in the male pelvis and thus enable accurate MRI-based RTP for prostate cancer patients with varying tissue anatomy and body fat contents. Methods: T{sub 1}/T{sub 2}*-weighted MRI intensity values and standard computed tomography (CT) image HUs in the male pelvis were analyzed using image data of 10 prostate cancer patients. The collected data were utilized to generate a dual model HU conversion technique from MRI intensity values of the single image set separately within and outside of contoured pelvic bones. Within the bone segment local MRI intensity values were converted to HUs by applying a second-order polynomial model. This model was tuned for each patient by two patient-specific adjustments: MR signal normalization to correct shifts in absolute intensity level and application of a cutoff value to accurately represent low density bony tissue HUs. For soft tissues, such as fat and muscle, located outside of the bone contours, a threshold-based segmentation method without requirements for any patient-specific adjustments was introduced to convert MRI intensity values into HUs. The dual model HU conversion technique was implemented by constructing pseudo-CT images for 10 other prostate cancer patients. The feasibility of these images for RTP was evaluated by comparing HUs in the generated pseudo-CT images with those in standard CT images, and by determining deviations in MRI-based dose distributions compared to those in CT images with 7-field intensity modulated radiation therapy (IMRT) with the anisotropic analytical algorithm and 360° volumetric-modulated arc therapy (VMAT) with the Voxel Monte Carlo algorithm. Results: The average HU differences between the constructed pseudo-CT images and standard CT images of each test patient ranged from ?2 to 5 HUs and from 22 to 78 HUs in soft and bony tissues, respectively. The average local absolute value differences were 11 HUs in soft tissues and 99 HUs in bones. The planning target volume doses (volumes 95%, 50%, 5%) in the pseudo-CT images were within 0.8% compared to those in CT images in all of the 20 treatment plans. The average deviation was 0.3%. With all the test patients over 94% (IMRT) and 92% (VMAT) of dose points within body (lower than 10% of maximum dose suppressed) passed the 1 mm and 1% 2D gamma index criterion. The statistical tests (t- and F-tests) showed significantly improved (p ? 0.05) HU and dose calculation accuracies with the soft tissue conversion method instead of homogeneous representation of these tissues in MRI-based RTP images. Conclusions: This study indicates that it is possible to construct high quality pseudo-CT images by converting the intensity values of a single MRI series into HUs in the male pelvis, and to use these images for accurate MRI-based prostate RTP dose calculations.

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

    SciTech Connect (OSTI)

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

    1994-12-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Shapiro, Mikhail G.

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Wang, Q.; Hu, Chia-Ren.

    2004-01-01T23:59:59.000Z

    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...

  12. A Simple and Fast Iterative Soft-thresholding Algorithm for Tight Frames in Compressed Sensing Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Liu, Yunsong; Cai, Jian-Feng; Guo, Di; Chen, Zhong; Qu, Xiaobo

    2015-01-01T23:59:59.000Z

    Compressed sensing has shown great potentials in accelerating magnetic resonance imaging. Fast image reconstruction and high image quality are two main issues faced by this new technology. It has been shown that, redundant image representations, e.g. tight frames, can significantly improve the image quality. But how to efficiently solve the reconstruction problem with these redundant representation systems is still challenging. This paper attempts to address the problem of applying fast iterative soft-thresholding algorithm (FISTA) to tight frames based magnetic resonance image reconstruction. By introducing the canonical dual frame, we construct an orthogonal projection operator on the range of the analysis sparsity operator and propose a new algorithm, called the projected FISTA (pFISTA). We theoretically prove that pFISTA converges to the minimum of a function with a balanced tight frame sparsity. One major advantage of pFISTA is that only one extra parameter, the step size, is introduced and the numerical...

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

    SciTech Connect (OSTI)

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

    1994-04-01T23:59:59.000Z

    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.

  14. 1,2-Hydroxypyridonates as Contrast Agents for Magnetic Resonance Imaging: TREN-1,2-HOPO

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    Hydroxypyridonate, Gadolinium, Europium, MRI, Fluorescence,was added a solution of europium chloride hexahydrate (36with the formation of europium hydroxide. 30 The competition

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

    SciTech Connect (OSTI)

    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

    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.

  16. AN APPROACH FOR INTERSUBJECT ANALYSIS OF 3D BRAIN IMAGES BASED ON CONFORMAL GEOMETRY

    E-Print Network [OSTI]

    Hua, Jing

    ABSTRACT Recent advances in imaging technologies, such as Magnetic Resonance Imaging (MRI), Positron technologies have accelerated brain research in many aspects [10, 12, 13]. In order to enable comparison that it minimizes the landmark mismatch energy [4] and Wang et al. introduced the application of compound energy

  17. 3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data

    E-Print Network [OSTI]

    Thompson, Paul

    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

  18. Engineered metalloproteins as contrast sensors for molecular fMRI

    E-Print Network [OSTI]

    Lelyveld, Victor S

    2010-01-01T23:59:59.000Z

    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. ...

  19. SQUID detected NMR and MRI at ultralow fields

    DOE Patents [OSTI]

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

    2005-04-26T23:59:59.000Z

    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.

  20. Squid detected NMR and MRI at ultralow fields

    DOE Patents [OSTI]

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

    2006-05-30T23:59:59.000Z

    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.

  1. SQUID detected NMR and MRI at ultralow fields

    DOE Patents [OSTI]

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

    2006-10-03T23:59:59.000Z

    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.

  2. Squid detected NMR and MRI at ultralow fields

    DOE Patents [OSTI]

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

    2008-12-16T23:59:59.000Z

    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.

  3. Squid detected NMR and MRI at ultralow fields

    DOE Patents [OSTI]

    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

    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.

  4. Comparative analysis of nonlinear dimensionality reduction techniques for breast MRI segmentation

    SciTech Connect (OSTI)

    Akhbardeh, Alireza; Jacobs, Michael A. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 (United States) and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 (United States)

    2012-04-15T23:59:59.000Z

    Purpose: Visualization of anatomical structures using radiological imaging methods is an important tool in medicine to differentiate normal from pathological tissue and can generate large amounts of data for a radiologist to read. Integrating these large data sets is difficult and time-consuming. A new approach uses both supervised and unsupervised advanced machine learning techniques to visualize and segment radiological data. This study describes the application of a novel hybrid scheme, based on combining wavelet transform and nonlinear dimensionality reduction (NLDR) methods, to breast magnetic resonance imaging (MRI) data using three well-established NLDR techniques, namely, ISOMAP, local linear embedding (LLE), and diffusion maps (DfM), to perform a comparative performance analysis. Methods: Twenty-five breast lesion subjects were scanned using a 3T scanner. MRI sequences used were T1-weighted, T2-weighted, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) imaging. The hybrid scheme consisted of two steps: preprocessing and postprocessing of the data. The preprocessing step was applied for B{sub 1} inhomogeneity correction, image registration, and wavelet-based image compression to match and denoise the data. In the postprocessing step, MRI parameters were considered data dimensions and the NLDR-based hybrid approach was applied to integrate the MRI parameters into a single image, termed the embedded image. This was achieved by mapping all pixel intensities from the higher dimension to a lower dimensional (embedded) space. For validation, the authors compared the hybrid NLDR with linear methods of principal component analysis (PCA) and multidimensional scaling (MDS) using synthetic data. For the clinical application, the authors used breast MRI data, comparison was performed using the postcontrast DCE MRI image and evaluating the congruence of the segmented lesions. Results: The NLDR-based hybrid approach was able to define and segment both synthetic and clinical data. In the synthetic data, the authors demonstrated the performance of the NLDR method compared with conventional linear DR methods. The NLDR approach enabled successful segmentation of the structures, whereas, in most cases, PCA and MDS failed. The NLDR approach was able to segment different breast tissue types with a high accuracy and the embedded image of the breast MRI data demonstrated fuzzy boundaries between the different types of breast tissue, i.e., fatty, glandular, and tissue with lesions (>86%). Conclusions: The proposed hybrid NLDR methods were able to segment clinical breast data with a high accuracy and construct an embedded image that visualized the contribution of different radiological parameters.

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

    SciTech Connect (OSTI)

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

    2012-12-15T23:59:59.000Z

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

  6. MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization

    SciTech Connect (OSTI)

    Burt, Scott R; Burt, Scott R.

    2008-06-25T23:59:59.000Z

    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.

  7. NMR and MRI apparatus and method

    DOE Patents [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Glover, Gary H.

    Neuroimaging at 1.5 T and 3.0 T: Comparison of Oxygenation-Sensitive Magnetic Resonance Imaging of the human brain at 1.5 and 3.0 T. At the higher field spiral gradient-echo (GRE) brain images revealed and becomes a larger fraction of the total noise at 3.0 T. Activation of the primary motor and visual cortex

  9. Imaging Agents DOI: 10.1002/anie.201301135

    E-Print Network [OSTI]

    Gao, Jinming

    Takahashi, A. Dean Sherry, and Jinming Gao* Magnetic resonance imaging (MRI) is a powerful non- invasive a "reverse" pH gradient across the cell membrane is observed in cancer cells compared to normal cells.[11 19 F signal. b) Structural formula of three representative diblock copolymers containing different p

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

    DOE Patents [OSTI]

    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

    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.

  11. 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)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  14. The Physiological Basis of BOLD Functional MRI /

    E-Print Network [OSTI]

    Griffeth, Valerie Ewing McClintock

    2013-01-01T23:59:59.000Z

    metabolism Detailed biophysical model of the BOLD response Functional magnetic resonance imaging Generalized calibration model General linear model Gradient

  15. NMR/MRI with hyperpolarized gas and high Tc SQUID

    DOE Patents [OSTI]

    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

    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.

  16. 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)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Jedynak, Bruno M.

    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

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

    DOE Patents [OSTI]

    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

    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.

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

    DOE Patents [OSTI]

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

    2006-01-24T23:59:59.000Z

    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.

  2. 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]

    Yallapragada, Naresh

    2009-05-15T23:59:59.000Z

    , 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...

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

    E-Print Network [OSTI]

    Usey, Michael Christopher

    1995-01-01T23:59:59.000Z

    , 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...

  4. A novel strategy for surface modification of superparamagnetic iron oxide nanoparticles for lung cancer imaging

    E-Print Network [OSTI]

    Gao, Jinming

    A novel strategy for surface modification of superparamagnetic iron oxide nanoparticles for lung Superparamagnetic iron oxide (SPIO) nanoparticles are widely used in magnetic resonance imaging (MRI) as versatile-step procedure for the surface functionalization of SPIO nanoparticles with a lung cancer-targeting peptide

  5. NACoM2003 Extended Abstracts 1 --6 Fast image registration --a variational approach

    E-Print Network [OSTI]

    Modersitzki, Jan

    Fischer # and Jan Modersitzki Institute of Mathematics, University of LË?ubeck, D­23560 LË?ubeck, Germany#erent modalities, like for example computer tomography (CT) and magnetic resonance imaging (MRI). To be successful measure. For this type of problems, we provide a toolbox of registration routines which enables the user

  6. Progress on detection of liquid explosives using ultra-low field MRI

    SciTech Connect (OSTI)

    Espy, Michelle A [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory; Schuttz, Larry M [Los Alamos National Laboratory; Baguisa, Shermiyah [Los Alamos National Laboratory; Dunkerley, David [Los Alamos National Laboratory; Magnelind, Per [Los Alamos National Laboratory; Owens, Tuba [Los Alamos National Laboratory; Sandin, Henrik [Los Alamos National Laboratory; Urbaitis, Algis [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) methods are widely used in medicine, chemistry and industry. Over the past several years there has been increasing interest in performing NMR and MRI in the ultra-low field (ULF) regime, with measurement field strengths of 10-100 microTesla and pre-polarization fields of 30-50 mTesla. The real-time signal-to-noise ratio for such measurements is about 100. Our group at LANL has built and demonstrated the performance of SQUID-based ULF NMR/MRI instrumentation for classification of materials and detection of liquid explosives via their relaxation properties measured at ULF, using T{sub 1}, and T{sub 2}, and T{sub 1} frequency dispersion. We are also beginning to investigate the performance of induction coils as sensors. Here we present recent progress on the applications of ULF MR to the detection of liquid explosives, in imaging and relaxometry.

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

    Office of Science (SC) Website

    supported by: NIH, NASA Impactbenefit to spin-off field: Static & dynamic imaging of lungs, heart, and possibly the brain, possible imaging of astronauts 'Hyperpolarized gas...

  8. 445ISSN 1755-519110.2217/IIM.10.33 2010 Future Medicine Ltd Imaging Med. (2010) 2(4), 445457 MRI artifacts and correction strategies

    E-Print Network [OSTI]

    Southern California, University of

    2010-01-01T23:59:59.000Z

    . Perhaps most importantly, because it does not rely on ionizing radiation, MRI is safe for serial by a superconductive coil, one or more radiofrequency (RF) fields, and several weak magnetic fields generated by three

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

    E-Print Network [OSTI]

    Gollub, Randy L.

    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 ...

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

    E-Print Network [OSTI]

    Gollub, Randy L.

    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 ...

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

    E-Print Network [OSTI]

    Thompson, Paul

    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

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

    DOE Patents [OSTI]

    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

    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.

  13. Enhancement of NMR and MRI in the presence of hyperpolarized noble gases

    DOE Patents [OSTI]

    Pines, Alexander; Budinger, Thomas; Navon, Gil; Song, Yi-Qiao; Appelt, Stephan; Bifone, Angelo; Taylor, Rebecca; Goodson, Boyd; Seydoux, Roberto; Room, Toomas; Pietrass, Tanja

    2004-11-16T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Kennth Marken

    2006-08-11T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  16. Systemic, local, and imaging biomarkers of brain injury: more needed, and better use of those already established?

    E-Print Network [OSTI]

    Carpenter, Keri L. H.; Czosnyka, Marek; Jalloh, Ibrahim; Newcombe, Virginia F. J.; Helmy, Adel; Shannon, Richard J.; Budohoski, Karol P.; Kolias, Angelos G.; Kirkpatrick, Peter J.; Carpenter, Thomas Adrian; Menon, David K.; Hutchinson, Peter J.

    2015-02-18T23:59:59.000Z

    anisotropy; FDG, 18F-fluorodeoxyglucose; FLAIR, fluid-attenuated inversion recovery; GABA, gamma-aminobutyric acid; GCS, Glas- gow coma scale score; GFAP, glial fibrillary acidic protein; GOS, Glasgow outcome scale score; GE, gradient echo; GRE, gradient... dehydrogenase; LPR, lac- tate/pyruvate ratio; MMP, matrix metalloprotease; MRI, magnetic resonance imag- ing; MRS, magnetic resonance spectroscopy; NAA, N -acetylaspartate; NAAG, N - acetylaspartylglutamate; NAD+, nicotine adenine dinucleotide (oxidized form...

  17. Adjustable permanent magnet assembly for NMR and MRI

    DOE Patents [OSTI]

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

    2013-10-29T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    McCombs, Jessica R. (Jessica Rose)

    2013-01-01T23:59:59.000Z

    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 ...

  19. A Survey of Prostate Segmentation Methodologies in Ultrasound, Magnetic Resonance and Computed Tomography Images

    E-Print Network [OSTI]

    Boyer, Edmond

    A Survey of Prostate Segmentation Methodologies in Ultrasound, Magnetic Resonance and Computed@gmail.com (Soumya Ghose), aoliver@eia.udg.edu (Arnau Oliver), marly@eia.udg.edu (Robert Mart´i), llado@eia.udg.edu (Xavier Llad´o), jordif@eia.udg.edu (Jordi Freixenet), jhimlimitra@yahoo.com (Jhimli Mitra), desire

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

    DOE Patents [OSTI]

    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

    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.

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

    DOE Patents [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Duncan, James S.

    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

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Konofagou, Elisa E.

    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

  6. A novel electron gun for inline MRI-linac configurations

    SciTech Connect (OSTI)

    Constantin, Drago? E., E-mail: dragos.constantin@varian.com; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States)] [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Holloway, Lois [Liverpool and Macarthur Cancer Therapy Centres, The University of Sydney, NSW 2006 (Australia)] [Liverpool and Macarthur Cancer Therapy Centres, The University of Sydney, NSW 2006 (Australia); Keall, Paul J. [Radiation Physics Laboratory, The University of Sydney, NSW 2006 (Australia)] [Radiation Physics Laboratory, The University of Sydney, NSW 2006 (Australia)

    2014-02-15T23:59:59.000Z

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T magnet without capture efficiency reduction below the experimental value in zero field. In this range of linac displacements, the electron beam generated by the new gun geometry is more effectively injected into the linac in the presence of an external magnetic field, resulting in approximately 20% increase of the target current compared to the original gun geometry behavior at zero field. The new gun geometry can generate and accelerate electron beams in external magnetic fields without current loss for fields higher than 0.11 T. The new electron-gun geometry is robust enough to function in the fringe fields of the other two magnets with a target current loss of no more than 16% with respect to the current obtained with no external magnetic fields. Conclusions: In this work, a specially designed electron gun was presented which can operate in the presence of axisymmetric strong magnetic fringe fields of MRI magnets. Computer simulations show that the electron gun can produce high quality beams which can be injected into a straight through linac such as Varian 600C and accelerated with more efficiency in the presence of the external magnetic fields. Also, the new configuration allows linac displacements along the magnet axis in a range equal to the diameter of the imaging spherical volume of the magnet under consideration. The new electron gun-linac system can function in the fringe field of a MRI magnet if the field strength at the cathode position is higher than 0.11 T. The capture efficiency of the linac depends on the magnetic field strength and the field gradient. The higher the gradient the better the capture efficiency. The capture efficiency does not degrade more than 16%.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Bosshard, John 1983-

    2012-08-20T23:59:59.000Z

    70% increase in SNR [62]. The same group used an array of four arc shaped coils around a cylinder for microscopy for SENSE and GRAPPA accelerated imaging [63]. The greater field of view provided by an array of small coils was noted by Laistler et...

  9. IMMEDIATE JOB OPENING MRI technical developments and applications

    E-Print Network [OSTI]

    Duong, Timothy Q.

    ) the applications of these innovative imaging technologies to study anatomy, metabolism, physiology (such as blood + AC88 high performance gradient insert 6) MRI: 3T/90cm whole-body Philips Achieva There are also

  10. IMMEDIATE JOB OPENINGS MRI technical developments and applications

    E-Print Network [OSTI]

    Duong, Timothy Q.

    ) the applications of these innovative imaging technologies to study anatomy, metabolism, physiology (such as blood) MRI: 3T/90cm whole-body Siemens TIM Trio + AC88 high performance gradient insert, and 6) Access

  11. MRI Predictive Factors for Tumor Response in Rectal Cancer Following Neoadjuvant Chemoradiation Therapy - Implications for Induction Chemotherapy?

    SciTech Connect (OSTI)

    Yu, Stanley K.T.; Tait, Diana [Radiotherapy Department, The Royal Marsden, Sutton/London (United Kingdom); Chau, Ian [Department of Medicine, The Royal Marsden, Sutton/London (United Kingdom); Brown, Gina, E-mail: gina.brown@rmh.nhs.uk [Academic Radiology Department, The Royal Marsden, Sutton/London (United Kingdom)

    2013-11-01T23:59:59.000Z

    Purpose: Clinical and magnetic resonance imaging (MRI) characteristics at baseline and following chemoradiation therapy (CRT) most strongly associated with histopathologic response were investigated and survival outcomes evaluated in accordance with imaging and pathological response. Methods and Materials: Responders were defined as mrT3c/d-4 downstaged to ypT0-2 on pathology or low at risk mrT2 downstaged to ypT1 or T0. Multivariate logistic regression of baseline and posttreatment MRI: T, N, extramural venous invasion (EMVI), circumferential resection margin, craniocaudal length <5 cm, and MRI tumor height ?5 cm were used to identify independent predictor(s) for response. An association between induction chemotherapy and EMVI status was analyzed. Survival outcomes for pathologic and MRI responders and nonresponders were analyzed. Results: Two hundred eighty-one patients were eligible; 114 (41%) patients were pathology responders. Baseline MRI negative EMVI (odds ratio 2.94, P=.007), tumor height ?5 cm (OR 1.96, P=.02), and mrEMVI status change (positive to negative) following CRT (OR 3.09, P<.001) were the only predictors for response. There was a strong association detected between induction chemotherapy and ymrEMVI status change after CRT (OR 9.0, P<.003). ymrT0-2 gave a positive predictive value of 80% and OR of 9.1 for ypT0-2. ymrN stage accuracy of ypN stage was 75%. Three-year disease-free survival for pathology and MRI responders were similar at 80% and 79% and significantly better than poor responders. Conclusions: Tumor height and mrEMVI status are more important than baseline size and stage of the tumor as predictors of response to CRT. Both MRI- and pathologic-defined responders have significantly improved survival. “Good response” to CRT in locally advanced rectal cancer with ypT0-2 carries significantly better 3-year overall survival and disease-free survival. Use of induction chemotherapy for improving mrEMVI status and knowledge of MRI predictive factors could be taken into account in the pursuit of individualized neoadjuvant treatments for patients with rectal cancer.

  12. Medical Image Registration: A Quick Win

    E-Print Network [OSTI]

    Ansorge, Richard

    2008-11-11T23:59:59.000Z

    Medical Image Registration A Quick Win Richard Ansorge The problem CT, MRI, PET and Ultrasound produce 3D volume images Typically 256 x 256 x 256 = 16,777,216 image voxels. Combining modalities (inter modality) gives extra information. Repeated... imaging over time same modality, e.g. MRI, (intra modality) equally important. Have to spatially register the images. Example – brain lesion CT MRI PET PET-MR Fusion The PET image shows...

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  15. Use of 3.0-T MRI for Stereotactic Radiosurgery Planning for Treatment of Brain Metastases: A Single-Institution Retrospective Review

    SciTech Connect (OSTI)

    Saconn, Paul A.; Shaw, Edward G.; Chan, Michael D.; Squire, Sarah E. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States); Johnson, Annette J. [Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States); McMullen, Kevin P. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States); Tatter, Stephen B.; Ellis, Thomas L. [Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States); Lovato, James [Department of Biostatistics, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States); Bourland, J. Daniel; Ekstrand, Kenneth E.; DeGuzman, Allan F. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States); Munley, Michael T., E-mail: mmunley@wfubmc.ed [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina (United States)

    2010-11-15T23:59:59.000Z

    Purpose: To investigate the efficacy of 3.0-T magnetic resonance imaging (MRI) for detecting brain metastases for stereotactic radiosurgery (SRS) planning. Methods and Materials: All adult patients scheduled for SRS treatment for brain metastases at our institution between October 2005 and January 2008 were eligible for analysis. All patients underwent radiosurgery treatment planning 3.0-T MRI on the day of scheduled radiosurgery and a diagnostic 1.5-T MRI in the days or weeks prior to radiosurgery for comparison. Both scans were interpreted by neuroradiologists who reported their findings in the radiology reports. We performed a retrospective review of the radiology reports to determine the number of brain metastases identified using each MRI system. Results: Of 254 patients scheduled for treatment from October 2005 to January 2008, 138 patients had radiology reports that explicitly described the number of metastases identified on both scans. With a median interval of 17 days (range, 1-82) between scans, the number of metastases detected using 1.5-T MRI system ranged from 1 to 5 and from 1 to 8 using the 3.0 T-MRI system. Twenty-two percent of patients were found to have a greater number of metastases with the 3.0 T-MRI system. The difference in number of metastases detected between the two scans for the entire cohort ranged from 0 to 6. Neither histology (p = 0.52 by chi-sq test) nor time between scans (p = 0.62 by linear regression) were significantly associated with the difference in number of metastases between scans. Conclusions: The 3.0-T MRI system appears to be superior to a 1.5-T MRI system for detecting brain metastases, which may have significant implications in determining the appropriate treatment modality. Our findings suggest the need for a prospectively designed study to further evaluate the use of a 3.0 T-MRI system for stereotactic radiosurgery planning in the treatment of brain metastases.

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

    E-Print Network [OSTI]

    Barnett, Alex

    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

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

    E-Print Network [OSTI]

    Liu, Xiaoqun

    2009-05-15T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Leahy, Richard M.

    of MRI values to absolute CT intensities [3]. Rotating a PET transmission source around the animalAtlas-based attenuation correction for small animal PET/MRI scanners 1 Abhijit J. Chaudhari PET/MRI scanners producing anatomically co-registered simultaneously-acquired images of morphology

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

    E-Print Network [OSTI]

    van Stokkum, Ivo

    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

  20. Wavelet based characterization of ex vivo vertebral trabecular bone structure with 3T MRI compared to microCT

    SciTech Connect (OSTI)

    Krug, R; Carballido-Gamio, J; Burghardt, A; Haase, S; Sedat, J W; Moss, W C; Majumdar, S

    2005-04-11T23:59:59.000Z

    Trabecular bone structure and bone density contribute to the strength of bone and are important in the study of osteoporosis. Wavelets are a powerful tool to characterize and quantify texture in an image. In this study the thickness of trabecular bone was analyzed in 8 cylindrical cores of the vertebral spine. Images were obtained from 3 Tesla (T) magnetic resonance imaging (MRI) and micro-computed tomography ({micro}CT). Results from the wavelet based analysis of trabecular bone were compared with standard two-dimensional structural parameters (analogous to bone histomorphometry) obtained using mean intercept length (MR images) and direct 3D distance transformation methods ({micro}CT images). Additionally, the bone volume fraction was determined from MR images. We conclude that the wavelet based analyses delivers comparable results to the established MR histomorphometric measurements. The average deviation in trabecular thickness was less than one pixel size between the wavelet and the standard approach for both MR and {micro}CT analysis. Since the wavelet based method is less sensitive to image noise, we see an advantage of wavelet analysis of trabecular bone for MR imaging when going to higher resolution.

  1. NMR, MRI, and spectroscopic MRI in inhomogeneous fields

    DOE Patents [OSTI]

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

    2013-12-24T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2008-10-29T23:59:59.000Z

    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.

  3. Semi-resonant operation of a fiber-cantilever piezotube scanner for stable optical coherence tomography endoscope imaging

    E-Print Network [OSTI]

    Moon, Sucbei; Lee, Sang-Won; Rubinstein, Marc; Wong, Brian J. F; Chen, Zhongping

    2010-01-01T23:59:59.000Z

    in-phase driving signals can be described as a line with aline were added for comparing the two in each column. Drivingdriving axes (X and Y) in the vicinity of their lowest resonance peaks. Solid lines

  4. Modeling sickle cell vasoocculsion in the rat leg: Quantification of trapped sickle cells and correlation with sup 31 P metabolic and sup 1 H magnetic resonance imaging changes

    SciTech Connect (OSTI)

    Fabry, M.E.; Rajanayagam, V.; Fine, E.; Holland, S.; Gore, J.C.; Nagel, R.L.; Kaul, D.K. (Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY (USA))

    1989-05-01T23:59:59.000Z

    The authors have developed an animal model to elucidate the acute effects of perfusion abnormalities on muscle metabolism induced by different density-defined classes of erythrocytes isolated from sickle cell anemia patients. Technetium-99m ({sup 99m}Tc)-labeled, saline-washed normal (AA), homozygous sickle (SS), or high-density SS (SS4) erythrocytes were injected into the femoral artery of the rat and quantitative {sup 99m}Tc imaging, {sup 31}P magnetic resonance spectroscopy by surface coil at 2 teslas, and {sup 1}H magnetic resonance imaging at 0.15 tesla were performed. Between 5 and 25 {mu}l of SS4 cells was trapped in the microcirculation of the thigh. In contrast, fewer SS discocytes (SS2) or AA cells were trapped. After injection of SS4 cells an initial increase in inorganic phosphate was observed in the region of the thigh served by the femoral artery, intracellular pH decreased, and subsequently the proton relaxation time T{sub 1} reached a broad maximum at 18-28 hr. When T{sub 1} obtained at this time was plotted against the volume of cells trapped, an increase of T{sub 1} over the control value of 411 {plus minus} 48 msec was found that was proportional to the number of cells trapped. They conclude that the densest SS cells are most effective at producing vasoocclusion. The extent of the change detected by {sup 1}H magnetic resonance imaging is dependent on the amount of cells trapped in the microcirculation and the magnitude of the initial increase of inorganic phosphate.

  5. SU-E-J-239: IMRT Planning of Prostate Cancer for a MRI-Linac Based On MRI Only

    SciTech Connect (OSTI)

    Chen, X; Prior, P; Paulson, E; Lawton, C; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2014-06-01T23:59:59.000Z

    Purpose: : To investigate dosimetric differences between MRI- and CT-based IMRT planning for prostate cancer, the impact of a magnetic field in a MRI-Linac, and to explore the feasibility of IMRT planning based on MRI alone. Methods: IMRT plans were generated based on CT and MRI images acquired on two representative prostate-cancer patients using clinical dose volume constraints. A research planning system (Monaco, Elekta), which employs a Monte Carlo dose engine and includes a perpendicular magnetic field of 1.5T from an MRI-Linac, was used. Bulk electron density assignments based on organ-specific values from ICRU 46 were used to convert MRI (T2) to pseudo CT. With the same beam configuration as in the original CT plan, 5 additional plans were generated based on CT or MRI, with or without optimization (i.e., just recalculation) and with or without the magnetic field. The plan quality in terms of commonly used dose volume (DV) parameters for all plans was compared. The statistical uncertainty on dose was < 1%. Results: For plans with the same contour set but without re-optimization, the DV parameters were different from those for the original CT plan, mostly less than 5% with a few exceptions. These differences were reduced to mostly less than 3% when the plans were re-optimized. For plans with contours from MRI, the differences in the DV parameters varied depending on the difference in the contours as compared to CT. For the optimized plans with contours from MR, the differences for PTV were less than 3%. Conclusion: The prostate IMRT plans based on MRI-only for a MR-Linac were practically similar as compared to the CT plan under the same beam and optimization configuration if the difference on the structure delineation is excluded, indicating the feasibility of using MRI-only for prostate IMRT.

  6. Amplification of Xenon NMR and MRI by remote detection

    SciTech Connect (OSTI)

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

    2003-03-31T23:59:59.000Z

    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.

  7. NMR (nuclear magnetic resonance) imaging for detecting binder/plasticizers in green-state structural ceramics. [SiC, Al/sub 2/O/sub 3/, and Si/sub 3/N/sub 4/

    SciTech Connect (OSTI)

    Ellingson, W.A.; Ackerman, J.L.; Gronemeyer, S.; Garrido, L.

    1987-06-01T23:59:59.000Z

    We have explored both a small-bore (<10 cm) experimental imaging system as well as a state-of-the-art medical imaging system relative to detection of the soft-solid (wax-like) binders used in ceramics. The ability to detect binders was evaluated on a 1.5-T medical MRI imager (Siemens Magnetom) using T/sub 1/-weighted imaging techniques and a 10-cm eye coil standard with the system. The ability to detect binders was also studied with a modified small-bore coil Technicare Facility using special rf and gradient coils. The initial results show that a medical system may not be able to detect binders unless elevated temperatures are used, whereas the experimental small-bore system shows the distribution quite well. In addition, higher magnetic field strength should be better for ceramics, since proton signal strength increases rapidly with the magnetic field strength. 11 refs., 9 figs., 3 tabs.

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

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    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

  9. Near-electrode imager

    DOE Patents [OSTI]

    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

    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.

  10. Method of performing MRI with an atomic magnetometer

    DOE Patents [OSTI]

    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

    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.

  11. Method of performing MRI with an atomic magnetometer

    DOE Patents [OSTI]

    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

    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.

  12. Nuclear magnetic resonance contrast agents

    DOE Patents [OSTI]

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

    1997-12-30T23:59:59.000Z

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

  13. 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]

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

    2006-06-14T23:59:59.000Z

    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.

  14. Dosimetric feasibility of real-time MRI-guided proton therapy

    SciTech Connect (OSTI)

    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

    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.

  15. Omni-tomography / Multi-tomography Integrating Multiple Modalities for Simultaneous Imaging

    E-Print Network [OSTI]

    Wang, Ge

    registration and combined acquisition on PET-CT, PET-MRI and other hybrid scanners. There are intrinsic relevant imaging mechanisms such as CT, MRI, PET, SPECT, US, optical, and possibly more. In this paper applications of omni-tomography. Key Words: Tomography, CT, MRI, PET, SPECT, US imaging, optical imaging

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

    E-Print Network [OSTI]

    Schiepers, Christiaan; Dahlbom, Magnus

    2011-01-01T23:59:59.000Z

    only [2] to combining PET and CT [3] and PET and MRI [4].varies widely between PET and CT, e.g. arms up or down,body imaging with MRI or PET/CT: the future for single-

  17. Injection-controlled laser resonator

    DOE Patents [OSTI]

    Chang, J.J.

    1995-07-18T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  19. 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...

  20. MRI-based treatment planning with pseudo CT generated through atlas registration

    SciTech Connect (OSTI)

    Uh, Jinsoo, E-mail: jinsoo.uh@stjude.org; Merchant, Thomas E.; Hua, Chiaho [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105 (United States)] [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105 (United States); Li, Yimei; Li, Xingyu [Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105 (United States)] [Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105 (United States)

    2014-05-15T23:59:59.000Z

    Purpose: To evaluate the feasibility and accuracy of magnetic resonance imaging (MRI)-based treatment planning using pseudo CTs generated through atlas registration. Methods: A pseudo CT, providing electron density information for dose calculation, was generated by deforming atlas CT images previously acquired on other patients. The authors tested 4 schemes of synthesizing a pseudo CT from single or multiple deformed atlas images: use of a single arbitrarily selected atlas, arithmetic mean process using 6 atlases, and pattern recognition with Gaussian process (PRGP) using 6 or 12 atlases. The required deformation for atlas CT images was derived from a nonlinear registration of conjugated atlas MR images to that of the patient of interest. The contrasts of atlas MR images were adjusted by histogram matching to reduce the effect of different sets of acquisition parameters. For comparison, the authors also tested a simple scheme assigning the Hounsfield unit of water to the entire patient volume. All pseudo CT generating schemes were applied to 14 patients with common pediatric brain tumors. The image similarity of real patient-specific CT and pseudo CTs constructed by different schemes was compared. Differences in computation times were also calculated. The real CT in the treatment planning system was replaced with the pseudo CT, and the dose distribution was recalculated to determine the difference. Results: The atlas approach generally performed better than assigning a bulk CT number to the entire patient volume. Comparing atlas-based schemes, those using multiple atlases outperformed the single atlas scheme. For multiple atlas schemes, the pseudo CTs were similar to the real CTs (correlation coefficient, 0.787–0.819). The calculated dose distribution was in close agreement with the original dose. Nearly the entire patient volume (98.3%–98.7%) satisfied the criteria of chi-evaluation (<2% maximum dose and 2 mm range). The dose to 95% of the volume and the percentage of volume receiving at least 95% of the prescription dose in the planning target volume differed from the original values by less than 2% of the prescription dose (root-mean-square, RMS < 1%). The PRGP scheme did not perform better than the arithmetic mean process with the same number of atlases. Increasing the number of atlases from 6 to 12 often resulted in improvements, but statistical significance was not always found. Conclusions: MRI-based treatment planning with pseudo CTs generated through atlas registration is feasible for pediatric brain tumor patients. The doses calculated from pseudo CTs agreed well with those from real CTs, showing dosimetric accuracy within 2% for the PTV when multiple atlases were used. The arithmetic mean process may be a reasonable choice over PRGP for the synthesis scheme considering performance and computational costs.

  1. 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

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  4. 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)

    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

    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.

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

    E-Print Network [OSTI]

    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

    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...

  6. 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)

    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

    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.

  7. Imaging and Radiography with Nuclear Resonance Fluorescence and Effective-Z (EZ-3D) Determination; SNM Detection Using Prompt Neutrons from Photon Induced Fission

    SciTech Connect (OSTI)

    Bertozzi, William; Hasty, Richard; Klimenko, Alexei; Korbly, Stephen E.; Ledoux, Robert J.; Park, William [Passport Systems, Inc., 70 Treble Cove Road, N. Billerica MA 01862 (United States)

    2009-03-10T23:59:59.000Z

    Four new technologies have been developed for use in non-intrusive inspection systems to detect nuclear materials, explosives and contraband. Nuclear Resonance Fluorescence (NRF) provides a three dimensional image of the isotopic content of a container. NRF determines the isotopic composition of a region and specifies the isotopic structure of the neighboring regions, thus providing the detailed isotopic composition of any threat. In transmission mode, NRF provides a two dimensional projection of the isotopic content of a container, much as standard X-ray radiography provides for density. The effective-Z method (EZ-3D) uses electromagnetic scattering processes to yield a three-dimensional map of the effective-Z and the density in a container. The EZ-3D method allows for a rapid discrimination based on effective Z and mass of materials such as those with high Z, as well as specifying regions of interest for other contraband. The energy spectrum of prompt neutrons from photon induced fission (PNPF) provides a unique identification of the presence of actinides and SNM. These four new technologies can be used independently or together to automatically determine the presence of hazardous materials or contraband. They can also be combined with other technologies to provide added specificity.

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

    SciTech Connect (OSTI)

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

    2008-10-01T23:59:59.000Z

    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.

  9. ORIGINAL ARTICLES An fMRI Study of Anterior Cingulate Function in

    E-Print Network [OSTI]

    Whalen, Paul J.

    integrity of anterior cingulate cortex in PTSD. Methods: Eight Vietnam combat veterans with PTSD (PTSD Group) and eight Vietnam combat veterans without PTSD (non-PTSD Group) underwent functional magnetic resonance General Negative compar- ison, the non-PTSD group exhibited significant fMRI blood oxygenation level

  10. 3D and 4D magnetic susceptibility tomography based on complex MR images

    DOE Patents [OSTI]

    Chen, Zikuan; Calhoun, Vince D

    2014-11-11T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Azevedo, Ricardo

    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

  12. University of Vermont Center for Biomedical Imaging

    SciTech Connect (OSTI)

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

    2013-08-02T23:59:59.000Z

    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.

  13. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMFormsGasReleaseSpeechesHallNotSeventyTechnologiesfacilityImaging

  14. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm)Hydrogen StorageITERITERBuilding EnergyImaging Print The

  15. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm)Hydrogen StorageITERITERBuilding EnergyImaging Print

  16. Image Fusion: Principles, Methods, and Applications

    E-Print Network [OSTI]

    Sroubek, Filip

    different sensors (visible and infrared, CT and NMR, or panchromatic and multispectral satellite images fusion is used to achieve high spatial and spectral resolutions by combining images from two sensors, one applications have appeared in medical imaging like simultaneous evaluation of CT, MRI, and/or PET images

  17. Magnetic Resonance Imaging of concrete

    E-Print Network [OSTI]

    Burgoyne, Chris

    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

  18. Techniques on Analysis of Photo Phase Shift Imaging

    E-Print Network [OSTI]

    Terry, Robin 1990-

    2012-04-12T23:59:59.000Z

    . Real-time MRI temperature mapping was evaluated using the magnitude and phase difference DICOM images. To reduce noise on the temperature maps, a mask was created using the magnitude images and eliminating pixel values greater than a set threshold...

  19. Improvements in Low Field MRI 

    E-Print Network [OSTI]

    Ogier, Stephen E

    2013-02-01T23:59:59.000Z

    previously developed a desktop MRI system, but the receiver was not phase stable. By digitizing the second RF pulse in the pulse sequence, it is possible to extract information about system delays to correct for phase shifts, rendering the system phase stable...

  20. 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...

  1. The MagLab's ultra-wide-bore (105mm) 21.1T NMR/MRI magnet provides an opportunity to use low gamma, low

    E-Print Network [OSTI]

    McQuade, D. Tyler

    The MagLab's ultra-wide-bore (105mm) 21.1T NMR/MRI magnet provides an opportunity to use low gamma, low sensitive nuclei for MR imaging. The potential of nuclei such as chlorine remains largely and the capability of MRI at ultra high magnetic fields to observe glioma. The finding of an increased concentration

  2. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

    SciTech Connect (OSTI)

    Dimopoulos, Johannes C.A. [Department of Radiation Oncology, Metropolitan Hospital, Athens (Greece); Schmid, Maximilian P., E-mail: maximilian.schmid@akhwien.at [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria); Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria)

    2012-04-01T23:59:59.000Z

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and organs at risk are in a comparable range. First clinical results indicate excellent LC. Further prospective multicenter studies are needed to establish this method and to confirm these results.

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

    E-Print Network [OSTI]

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

    2014-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

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

    1996-10-01T23:59:59.000Z

    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.

  5. SU-D-9A-03: STAMP: Simulator for Texture Analysis in MRI/PET

    SciTech Connect (OSTI)

    Laberge, S; Vallieres, M; Levesque, I R.; El Naqa, I [McGill University, Montreal, QC (Canada)

    2014-06-01T23:59:59.000Z

    Purpose: To develop a convenient simulation platform to facilitate PET/MR image analysis with the prospect of gaining a better understanding of the influence of acquisition parameters on PET/MRI textural features. The simulation platform is demonstrated by showing textural variations of a representative case study using different image acquisition parameters. Methods: The simulation platform is composed of MRI simulators JEMRIS and SIMRI to achieve simulations of customized MRI sequences on sample tumor models. The PET simulator GATE is used to get 2D and 3D Monte Carlo acquisitions of voxelized PET sources using a phantom geometry and a customized scanner architecture. The platform incorporates a series of graphical user interfaces written in Matlab. Two GUIs are used to facilitate communication with the simulation executables installed on a computer cluster. A third GUI is used to collect and display the clinical and simulated images, as well as fused PET/MRI images, and perform computation of textural features.To illustrate the capabilities of this platform, one FDG-PET and T1-weighted (T1w) digitized tumor models were generated from clinical images of a soft-tissue sarcoma patient. Numerically simulated MR images were produced using 3 different echo times (TE) and 5 different repetition times (TR). PET 2D images were simulated using an OSEM algorithm with 1 to 32 iterations and a post-reconstruction Gaussian filter of 0, 2, 4 or 6 mm width. Results: STAMP was successfully used to produce numerically simulated FDG-PET and MRI images, and to calculate their corresponding textures. Three typical textures (GLCM-Contrast, GLSZM-ZSV and NGTDM-Coarseness) were found to vary by a range of 45% on average compared to reference scanning conditions in the case of FDG-PET, and by a range of 40% in the case of T1w MRI. Conclusion: We have successfully developed a Matlab-based simulation platform to facilitate PET/MRI texture image analysis for outcome prediction.

  6. Harmonic analysis for the characterization and correction of geometric distortion in MRI

    SciTech Connect (OSTI)

    Tadic, Tony, E-mail: ttadic@gmail.com; Stanescu, Teodor [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Department of Medical Biophysics, University of Toronto, Toronto M5G 1L7 (Canada)

    2014-11-01T23:59:59.000Z

    Purpose: Magnetic resonance imaging (MRI) is gaining widespread use in radiation therapy planning, patient setup verification, and real-time guidance of radiation delivery. Successful implementation of these technologies relies on the development of simple and efficient methods to characterize and monitor the geometric distortions arising due to system imperfections and gradient nonlinearities. To this end, the authors present the theory and validation of a novel harmonic approach to the quantification of system-related distortions in MRI. Methods: The theory of spatial encoding in MRI is applied to demonstrate that the 3D distortion vector field (DVF) is given by the solution of a second-order boundary value problem (BVP). This BVP is comprised of Laplace’s equation and a limited measurement of the distortion on the boundary of a specified region of interest (ROI). An analytical series expansion solving this BVP within a spherical ROI is obtained, and a statistical uncertainty analysis is performed to determine how random errors in the boundary measurements propagate to the ROI interior. This series expansion is then evaluated to obtain volumetric DVF mappings that are compared to reference data obtained on a 3 T full-body scanner. This validation is performed within two spheres of 20 cm diameter (one centered at the scanner origin and the other offset +3 cm along each of the transverse directions). Initially, a high-order mapping requiring measurements at 5810 boundary points is used. Then, after exploring the impact of the boundary sampling density and the effect of series truncation, a reduced-order mapping requiring measurements at 302 boundary points is evaluated. Results: The volumetric DVF mappings obtained from the harmonic analysis are in good agreement with the reference data. Following distortion correction using the high-order mapping, the authors estimate a reduction in the mean distortion magnitude from 0.86 to 0.42 mm and from 0.93 to 0.39 mm within the central and offset ROIs, respectively. In addition, the fraction of points with a distortion magnitude greater than 1 mm is reduced from 35.6% to 2.8% and from 40.4% to 1.5%, respectively. Similarly, following correction using the reduced-order mapping, the mean distortion magnitude reduces to 0.45–0.42 mm within the central and offset ROIs, and the fraction of points with a distortion magnitude greater than 1 mm is reduced to 2.8% and 1.5%, respectively. Conclusions: A novel harmonic approach to the characterization of system-related distortions in MRI is presented. This method permits a complete and accurate mapping of the DVF within a specified ROI using a limited measurement of the distortion on the ROI boundary. This technique eliminates the requirement to exhaustively sample the DVF at a dense 3D array of points, thereby permitting the design of simple, inexpensive phantoms that may incorporate additional modules for auxiliary quality assurance objectives.

  7. 7 Tesla fMRI Reveals Systematic Functional Organization for Binocular Disparity in Dorsal Visual Cortex

    E-Print Network [OSTI]

    Goncalves, Nuno R.; Ban, Hiroshi; Sánchez-Panchuelo, Rosa M.; Francis, Susan T.; Schluppeck, Denis; Welchman, Andrew E.

    2015-02-18T23:59:59.000Z

    animal models, comparatively little is known about the local architecture of stereoscopic processing in the human brain. Here, we take advantage of the high spatial specificity and image contrast offered by 7 tesla fMRI to test for systematic organization...

  8. Studying MRI acquisition protocols of sustained sounds with a multimodal acquisition system

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    system which utilizes infrared emit- ting diodes (IREDs) requires that the sensors to be visible from a multimodal acquisition system which uses electromagnetogra- phy sensors to locate the US probe a millimetric accuracy 3D MRI images of the vocal tract have enabled more accurate evaluations of vocal tract

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

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    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

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

    SciTech Connect (OSTI)

    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

    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.

  11. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer Plant Jump to:LandownersLuther, Oklahoma:EnergyECO Auger <SmarTurbineMIT-MRI Ventures

  12. Resonance conditions

    E-Print Network [OSTI]

    P. Rebusco

    2005-10-14T23:59:59.000Z

    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.

  13. Absorption Mode FT-ICR Mass Spectrometry Imaging. | EMSL

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

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

  14. Hemangioma of the Interatrial Septum: CT and MRI Features

    SciTech Connect (OSTI)

    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

    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.

  15. Polarized Helium to Image the Lung

    E-Print Network [OSTI]

    Leduc, M; Leduc, Mich\\`{e}le; Nacher, Pierre-Jean

    2006-01-01T23:59:59.000Z

    The main findings of the european PHIL project (Polarised Helium to Image the Lung) are reported. State of the art optical pumping techniques for polarising ^3He gas are described. MRI methodological improvements allow dynamical ventilation images with a good resolution, ultimately limited by gas diffusion. Diffusion imaging appears as a robust method of lung diagnosis. A discussion of the potential advantage of low field MRI is presented. Selected PHIL results for emphysema are given, with the perspectives that this joint work opens up for the future of respiratory medicine.

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

    E-Print Network [OSTI]

    Schiepers, Christiaan; Dahlbom, Magnus

    2011-01-01T23:59:59.000Z

    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

  17. BIOSIGNAL 2002 Tagged cardiac MR images analysis

    E-Print Network [OSTI]

    Histace, Aymeric

    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

  18. Medical Imaging Computed Tomography (CT)

    E-Print Network [OSTI]

    Massey, Thomas N.

    Module 10 Medical Imaging · X-rays · Computed Tomography (CT) · Positron Emission Tomography (PET Sources PET-TOF #12;Four Sources PET #12;Four Sources PET-TOF #12;PET Scan MRI CT scan #12;Endocrine Gland,000 pixels! #12;Modern Example of CT Scan with the addition of Surface Shading Standard CT With Surface

  19. 4D tumor centroid tracking using orthogonal 2D dynamic MRI: Implications for radiotherapy planning

    SciTech Connect (OSTI)

    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

    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.

  20. 1610 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 11, 2012 MRI-Derived 3-D-Printed Breast Phantom

    E-Print Network [OSTI]

    Hagness, Susan C.

    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

  1. Hardeep S Mehta | EMSL

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

    and extensive instrument development experience. His work focuses on developing novel nuclear magnetic resonance (NMR)magnetic resonance imaging (MRI) instrumentation that...

  2. SU-E-I-23: Design and Clinical Application of External Marking Body in Multi- Mode Medical Images Registration and Fusion

    SciTech Connect (OSTI)

    Chen, Z; Gong, G [Shandong Cancer Hospital, Jinan, Shandong (China)

    2014-06-01T23:59:59.000Z

    Purpose: To design an external marking body (EMB) that could be visible on computed tomography (CT), magnetic resonance (MR), positron emission tomography (PET) and single-photon emission computed tomography (SPECT) images and to investigate the use of the EMB for multiple medical images registration and fusion in the clinic. Methods: We generated a solution containing paramagnetic metal ions and iodide ions (CT'MR dual-visible solution) that could be viewed on CT and MR images and multi-mode image visible solution (MIVS) that could be obtained by mixing radioactive nuclear material. A globular plastic theca (diameter: 3–6 mm) that mothball the MIVS and the EMB was brought by filling MIVS. The EMBs were fixed on the patient surface and CT, MR, PET and SPECT scans were obtained. The feasibility of clinical application and the display and registration error of EMB among different image modalities were investigated. Results: The dual-visible solution was highly dense on CT images (HU>700). A high signal was also found in all MR scanning (T1, T2, STIR and FLAIR) images, and the signal was higher than subcutaneous fat. EMB with radioactive nuclear material caused a radionuclide concentration area on PET and SPECT images, and the signal of EMB was similar to or higher than tumor signals. The theca with MIVS was clearly visible on all the images without artifact, and the shape was round or oval with a sharp edge. The maximum diameter display error was 0.3 ± 0.2mm on CT and MRI images, and 1.0 ± 0.3mm on PET and SPECT images. In addition, the registration accuracy of the theca center among multi-mode images was less than 1mm. Conclusion: The application of EMB with MIVS improves the registration and fusion accuracy of multi-mode medical images. Furthermore, it has the potential to ameliorate disease diagnosis and treatment outcome.

  3. SU-E-J-90: MRI-Based Treatment Simulation and Patient Setup for Radiation Therapy of Brain Cancer

    SciTech Connect (OSTI)

    Yang, Y [UCLA School of Medicine, Los Angeles, AA (United States); Cao, M; Han, F; Santhanam, A; Neylon, J; Gomez, C; Kaprealian, T; Sheng, K; Agazaryan, N; Low, D; Hu, P

    2014-06-01T23:59:59.000Z

    Purpose: Traditional radiation therapy of cancer is heavily dependent on CT. CT provides excellent depiction of the bones but lacks good soft tissue contrast, which makes contouring difficult. Often, MRIs are fused with CT to take advantage of its superior soft tissue contrast. Such an approach has drawbacks. It is desirable to perform treatment simulation entirely based on MRI. To achieve MR-based simulation for radiation therapy, bone imaging is an important challenge because of the low MR signal intensity from bone due to its ultra-short T2 and T1, which presents difficulty for both dose calculation and patient setup in terms of digitally reconstructed radiograph (DRR) generation. Current solutions will either require manual bone contouring or multiple MR scans. We present a technique to generate DRR using MRI with an Ultra Short Echo Time (UTE) sequence which is applicable to both OBI and ExacTrac 2D patient setup. Methods: Seven brain cancer patients were scanned at 1.5 Tesla using a radial UTE sequence. The sequence acquires two images at two different echo times. The two images were processed using in-house software. The resultant bone images were subsequently loaded into commercial systems to generate DRRs. Simulation and patient clinical on-board images were used to evaluate 2D patient setup with MRI-DRRs. Results: The majority bones are well visualized in all patients. The fused image of patient CT with the MR bone image demonstrates the accuracy of automatic bone identification using our technique. The generated DRR is of good quality. Accuracy of 2D patient setup by using MRI-DRR is comparable to CT-based 2D patient setup. Conclusion: This study shows the potential of DRR generation with single MR sequence. Further work will be needed on MR sequence development and post-processing procedure to achieve robust MR bone imaging for other human sites in addition to brain.

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

    E-Print Network [OSTI]

    Naphuket, Sood Ratanadilok

    1997-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

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

    2012-04-15T23:59:59.000Z

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

  6. 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...

  7. Physics of MRI Polytechnic University, Brooklyn, NY 11201

    E-Print Network [OSTI]

    Suel, Torsten

    than CT, more susceptible to patient motion CT MRI PET #12;EL582 MRI Physics Yao Wang, Polytechnic U structure (as with X-ray CT) · Provide high contrast between different soft tissues (X-ray CT cannot

  8. Regenerative feedback resonant circuit

    DOE Patents [OSTI]

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

    2014-09-02T23:59:59.000Z

    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.

  9. Efficient MR image reconstruction for compressed MR imaging Junzhou Huang

    E-Print Network [OSTI]

    Huang, Junzhou

    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

  10. Efficient MR Image Reconstruction for Compressed MR Imaging

    E-Print Network [OSTI]

    Huang, Junzhou

    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

  11. A high-field 3He Metastability Exchange Optical Pumping polarizer operating in a 1.5 T medical scanner for lung MRI

    E-Print Network [OSTI]

    Collier, G; Wojna, A; G?owacz, B; Suchanek, M; Olejniczak, Z; Dohnalik, T

    2013-01-01T23:59:59.000Z

    After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low pressure (~ 1 mbar), which results in a low magnetization production rate. A delicate polarization-preserving step of compression is also required. It was demonstrated in sealed cells that high nuclear polarization values can be obtained at higher pressures with MEOP, if performed at high magnetic field (non-standard conditions). In this work the feasibility of building a high-field polarizer that operates within a commercial 1.5 T scanner was evaluated. Preliminary measurements of nuclear polarization with sealed cells filled at different 3He gas pressures (1.33 to 267 mbar) were performed. The use of an annular shape for the laser beam increased by 25 % the achievable nuclear polarization equilibrium value (Meq) at 32 and 67 mbar as compared to a Gaussian beam shape. Meq...

  12. Accelerated Proton Echo Planar Spectroscopic Imaging (PEPSI) Using GRAPPA with a 32-Channel Phased-Array

    E-Print Network [OSTI]

    Accelerated Proton Echo Planar Spectroscopic Imaging (PEPSI) Using GRAPPA with a 32-Channel PhasedD proton echo planar spec- troscopic imaging (PEPSI) at 3T using generalized autocalibrat- ing words: proton echo planar spectroscopic imaging; PEPSI; MR spectroscopic imaging; parallel MRI; 32

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

    SciTech Connect (OSTI)

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

    1998-04-01T23:59:59.000Z

    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.

  14. AS30D Model of Hepatocellular Carcinoma: Tumorigenicity and Preliminary Characterization by Imaging, Histopathology, and Immunohistochemistry

    SciTech Connect (OSTI)

    Thompson, Scott M. [Mayo Clinic, Medical Scientist Training Program (United States)] [Mayo Clinic, Medical Scientist Training Program (United States); Callstrom, Matthew R. [Mayo Clinic, Department of Radiology (United States)] [Mayo Clinic, Department of Radiology (United States); Knudsen, Bruce [Mayo Clinic, Department of Laboratory Medicine and Pathology (United States)] [Mayo Clinic, Department of Laboratory Medicine and Pathology (United States); Anderson, Jill L. [Mayo Clinic, Division of Physiology and Bioengineering (United States)] [Mayo Clinic, Division of Physiology and Bioengineering (United States); Butters, Kim A.; Grande, Joseph P. [Mayo Clinic, Department of Laboratory Medicine and Pathology (United States)] [Mayo Clinic, Department of Laboratory Medicine and Pathology (United States); Roberts, Lewis R. [Mayo Clinic, Division of Gastroenterology and Hepatology (United States)] [Mayo Clinic, Division of Gastroenterology and Hepatology (United States); Woodrum, David A., E-mail: woodrum.david@mayo.edu [Mayo Clinic, Department of Radiology (United States)

    2013-02-15T23:59:59.000Z

    This study was designed to determine the tumorigenicity of the AS30D HCC cell line following orthotopic injection into rat liver and preliminarily characterize the tumor model by both magnetic resonance imaging (MRI) and ultrasound (US) as well as histopathology and immunohistochemistry.MaterialsAS30D cell line in vitro proliferation was assessed by using MTT assay. Female rats (N = 5) underwent injection of the AS30D cell line into one site in the liver. Rats subsequently underwent MR imaging at days 7 and 14 to assess tumor establishment and volume. One rat underwent US of the liver at day 7. Rats were euthanized at day 7 or 14 and livers were subjected to gross, histopathologic (H and E), and immunohistochemical (CD31) analysis to assess for tumor growth and neovascularization. AS30D cell line demonstrated an in vitro doubling time of 33.2 {+-} 5.3 h. MR imaging demonstrated hyperintense T2-weighted and hypointense T1-weighted lesions with tumor induction in five of five and three of three sites at days 7 and 14, respectively. The mean (SD) tumor volume was 126.1 {+-} 36.2 mm{sup 3} at day 7 (N = 5). US of the liver demonstrated a well-circumscribed, hypoechoic mass and comparison of tumor dimensions agreed well with MRI. Analysis of H and E- and CD31-stained sections demonstrated moderate-high grade epithelial tumors with minimal tumor necrosis and evidence of diffuse intratumoral and peritumoral neovascularization by day 7. AS30D HCC cell line is tumorigenic following orthotopic injection into rat liver and can be used to generate an early vascularizing, slower-growing rat HCC tumor model.

  15. 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)

    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

    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.

  16. Isotropic three-dimensional MRI-Fricke-infused gel dosimetry

    SciTech Connect (OSTI)

    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

    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.

  17. 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)

    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

    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.

  18. 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...

  19. 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...

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

    E-Print Network [OSTI]

    Utah, University of

    /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

  1. Original Research Comparison of MRI and 18

    E-Print Network [OSTI]

    Delp, Scott

    - age in the bone or cartilage as seen on MRI. Conclusion: Our results suggest that 18 F-NaF PET/CT may in increased tracer uptake (7). While 18F-NaF PET/CT is more expensive than Tc-99m MDP bone scintigraphy, there are a number of benefits of this modality. The advantages of 18 F-NaF PET/CT over bone scintigraphy techniques

  2. Single echo acquisition magnetic resonance imaging

    E-Print Network [OSTI]

    McDougall, Mary Preston

    2006-04-12T23:59:59.000Z

    ) for comparison to quasi- static field pattern modeling .................................................................................................37 3.25 Coil pattern with the appropriate signal and noise calculation areas marked for SNR evaluation...

  3. Accelerated Articles Surface Plasmon Resonance Imaging

    E-Print Network [OSTI]

    ) He, L.; Musick, M. D.; Nicewarner, S. R.; Salinas, F. G.; Benkovic, S. J.; Natan, M. J.; Keating, C

  4. Nanomechanical resonance detector

    DOE Patents [OSTI]

    Grossman, Jeffrey C; Zettl, Alexander K

    2013-10-29T23:59:59.000Z

    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.

  5. Ovenized microelectromechanical system (MEMS) resonator

    DOE Patents [OSTI]

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

    2014-03-11T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Van Veen, Barry D.

    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

  7. 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...

  8. Ultra-low field MRI of prostate cancer using SQUID detection

    E-Print Network [OSTI]

    Busch, Sarah Elizabeth

    2011-01-01T23:59:59.000Z

    coil. Chapter 3 3 Ultra low field MRI 3.1 Polarization TheUltra-low field MRI of prostate cancer using SQUID detectionSteven Conolly Spring 2011 Ultra-low field MRI of prostate

  9. Sensitivity-Encoded (SENSE) Proton Echo-Planar Spectroscopic Imaging (PEPSI) in the Human Brain

    E-Print Network [OSTI]

    Sensitivity-Encoded (SENSE) Proton Echo-Planar Spectroscopic Imaging (PEPSI) in the Human Brain Fa, such as proton echo-planar spectroscopic imaging (PEPSI), are capable of fast spectral-spatial encoding and thus enable acceleration of image acquisition times. Combining PEPSI with recent advances in parallel MRI

  10. 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

  11. Video Toroid Cavity Imager

    DOE Patents [OSTI]

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

    2004-08-10T23:59:59.000Z

    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.

  12. Array combination for parallel imaging in Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Spence, Dan Kenrick

    2007-09-17T23:59:59.000Z

    ......................................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...

  13. abnormal brain mri: Topics by E-print Network

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

    abnormal brain mri First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Improvement of MRI brain...

  14. ARTICLE IN PRESS 2 Expert knowledge-guided segmentation system for brain MRI

    E-Print Network [OSTI]

    Thompson, Paul

    U N C O R R EC TED PR O O F ARTICLE IN PRESS 1 2 Expert knowledge-guided segmentation system templates (simplex mesh surfaces) to the contours of the 17 target structures. These templates evolve resonance images; Simplex mesh surfaces; 3-D 26 segmentation system 27 28 Introduction 29 The rapid

  15. SU-D-18C-06: Initial Experience with Implementing MRI Safety Guidelines for Patients with Pacemakers - Medical Physicist Perspective

    SciTech Connect (OSTI)

    James, J; Place, V; Panda, A [Mayo Clinic, Scottsdale, AZ (United States); Edmonson, H [Mayo Clinic College of Medicine, Rochester, MN (United States); Felmlee, J [Mayo Clinic, Rochester, MN (United States); Pooley, R [Mayo Clinic, Jacksonville, FL (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Several institutions have developed MRI guidelines for patients with MR-unsafe or MR-conditional pacemakers. Here we highlight the role of a medical physicist in implementing these guidelines for non-pacemaker dependent patients. Guidelines: Implementing these guidelines requires involvement from several medical specialties and a strong collaboration with the site MRI supervisor to develop a structured workflow. A medical physicist is required to be present during the scan to supervise the MR scanning and to maintain a safety checklist that ensures: 1) uninterrupted patient communication with the technologist, 2) continuous patient physiologic monitoring (e.g. blood pressure and electrocardiography) by a trained nurse, 3) redundant patient vitals monitoring (e.g. pulse oximetry) due to the possibility of in vivo electrocardiography reading fluctuations during image acquisition. A radiologist is strongly recommended to be available to review the images before patients are discharged from the scanner. Pacemaker MRI should be restricted to 1.5T field strength. The MRI sequences should be optimized by the physicist with regards to: a) SAR: limited to <1.5 W/Kg for MR-unsafe pacemakers in normal operating mode, b) RF exposure time: <30 min, c) Coils: use T/R coils but not restricted to such, d) Artifacts: further optimization of sequences whenever image quality is compromised due to the pacemaker. In particular, cardiac, breast and left-shoulder MRIs are most susceptible to these artifacts. Possible strategies to lower the SAR include: a) BW reduction, 2) echo-train-length reduction, 3) increase TR, 4) decrease number of averages, 5) decrease flip angle, 6) reduce slices and/or a combination of all the options. Conclusion: A medical physicist in collaboration with the MR supervisor plays an important role in the supervision/implementation of safe MR scanning of pacemaker patients. Developing and establishing a workflow has enabled our institution to scan over 30 patients with pacemakers without complications, including 3 cardiac MR exams.

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

    SciTech Connect (OSTI)

    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

    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.

  17. 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

  18. Narrowband resonant transmitter

    DOE Patents [OSTI]

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

    2004-06-29T23:59:59.000Z

    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.

  19. Resonant snubber inverter

    DOE Patents [OSTI]

    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

    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.

  20. Resonant snubber inverter

    DOE Patents [OSTI]

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  2. 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

  3. 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

  4. 128 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 25, NO. 1, JANUARY 2006 Unwrapping of MR Phase Images Using a

    E-Print Network [OSTI]

    Koetter, Ralf

    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

  5. 106 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 29, NO. 1, JANUARY 2010 Feature Based Nonrigid Brain MR Image Registration

    E-Print Network [OSTI]

    Chung, Albert C. S.

    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

  6. Signals & Systems Prof. Mark Fowler

    E-Print Network [OSTI]

    Fowler, Mark

    monitoring, ultrasound imaging, magnetic resonance imaging (MRI) Image Processing 3D animation, image positioning in disk drives, laser control (e.g., printers, CD/DVD drives), engine & motor control, robots

  7. LABCOM resonator Phase 3

    SciTech Connect (OSTI)

    Keres, L.J.

    1990-11-01T23:59:59.000Z

    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.

  8. 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:...

  9. For more information, please contact Prof. Frank Fisher at Frank.Fisher@stevens.edu or 201-216-8913 STEVENS INSTITUTE OF TECHNOLOGY

    E-Print Network [OSTI]

    Fisher, Frank

    , Time: NOON Enabling Technologies for Robotic MRI-Guided Interventional Procedures Gregory S. Fischer Johns Hopkins University Magnetic Resonance Imaging (MRI) can provide high-quality 3D visualization the systems requirements development, robotic system design, controller design, system integration

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

    E-Print Network [OSTI]

    Triantafyllou, Christina

    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 ...

  11. Methods to assess changes in human brain structure across the lifecourse 

    E-Print Network [OSTI]

    Dickie, David Alexander

    2014-11-28T23:59:59.000Z

    Human brain structure can be measured across the lifecourse (“in vivo”) with magnetic resonance imaging (MRI). MRI data are often used to create “atlases” and statistical models of brain structure across the lifecourse. ...

  12. 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...

  13. MAGNETIC RESONANCE SCREENING FORM Name Height Weight

    E-Print Network [OSTI]

    Biederman, Irving

    feeding? Yes No 5. Do you have Sickle Cell Anemia or Thalassemia? Yes No The MRI room contains a very

  14. Tunable multiwalled nanotube resonator

    DOE Patents [OSTI]

    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

    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.

  15. Tunable multiwalled nanotube resonator

    DOE Patents [OSTI]

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

    2013-11-05T23:59:59.000Z

    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.

  16. Nuclear Resonance Fluorescence for Nuclear Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian Joseph

    2010-01-01T23:59:59.000Z

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

  17. Micro-machined resonator

    DOE Patents [OSTI]

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

    1993-03-30T23:59:59.000Z

    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.

  18. Content Based Image Retrieval based on Wavelet Transform coefficients distribution

    E-Print Network [OSTI]

    Boyer, Edmond

    : 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

  19. Injector with integrated resonator

    DOE Patents [OSTI]

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

    2014-07-29T23:59:59.000Z

    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.

  20. Resonant dielectric metamaterials

    DOE Patents [OSTI]

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

    2014-12-02T23:59:59.000Z

    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.

  1. Resonant nonlinear ultrasound spectroscopy

    DOE Patents [OSTI]

    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

    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.

  2. Imaging Arginine Kinase (AK) ExpressionImaging gene expression in tissues often relies on tissue extracts or

    E-Print Network [OSTI]

    Weston, Ken

    tracking of stem cells). MRI has, however, been limited in its ability to image the manufacturing of genes method could be used to detect the intracellular manufacturing within the leg muscles of a mouse to resolve the different 31P chemical shifts of PArg (red) and PCr (blue) (see Figure 1). In addition

  3. SU-E-J-71: Feasibility Study On MRI-Based BANG3 Gel Dosimetry Using Dual-Source Parallel RF Transmission System

    SciTech Connect (OSTI)

    Kim, S; Lee, J; Lee, D; Lee, S; Choe, B [The Catholic University of Korea, Seoul, Seoul (Korea, Republic of); Baek, H [Korea Basic Science Institute, Chungwon, Chungwon (Korea, Republic of)

    2014-06-01T23:59:59.000Z

    Purpose: In this work, we present the feasibility of use of the parallel RF transmission with multiple RF source (MultiTransmit) imaging in MRI-based polymer gel dosimetry. Methods: The commercially available BANG3 gel was used for gel dosimetry. Spin-spin relaxation rate R2 was used to quantify the absorbed dose. The image quality (signal-to-noise ratio, SNR; image uniformity) and B1 field inhomogeneity between conventional single-source and MultiTransmit MR imaging were compared. Finally, the estimated R2 uncertainty ?(R2) and dosimetric performance (i.e., dose resolution) between conventional single-source and MultiTransmit MR imaging were compared. Results: Image quality and B1 field homogeneity within each calibration vial and large phantom was statistically better in MultiTransmit imaging than in conventional single-source RF transmission imaging (P < 0.005 for all calibration vials). In particular, ?(R2) (defined as the standard uncertainty of R2) was lower on the MultiTransmit images than on the conventional single-source images. Furthermore, the MultiTransmit measurement gives a lower than that obtained using the conventional single-source method. Conclusion: The improved image quality and B1 homogeneity resulted in reduced dose uncertainty (i.e., ?(R2) and dose resolution) in MRI-based polymer gel dosimetry, suggesting that MultiTransmit MR imaging has potential benefits for use in clinical 3D gel dosimetry without the need for the complicated B1 field correction method.

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973ManagedStrategic|Aljazeera story onImaging (MRI)

  5. Enhanced oil recovery through water imbibition in fractured reservoirs using Nuclear Magnetic Resonance 

    E-Print Network [OSTI]

    Hervas Ordonez, Rafael Alejandro

    1994-01-01T23:59:59.000Z

    -iicro-fracture system. Nuclear Magnetic Resonance (NNM) sets of longitudinal and transverse profiles and images were recorded to visualize and quantify changes in fluid saturation inside the rock samples during the imbibition displacement tests. NMR oil saturation...

  6. Enhanced oil recovery through water imbibition in fractured reservoirs using Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Hervas Ordonez, Rafael Alejandro

    1994-01-01T23:59:59.000Z

    -iicro-fracture system. Nuclear Magnetic Resonance (NNM) sets of longitudinal and transverse profiles and images were recorded to visualize and quantify changes in fluid saturation inside the rock samples during the imbibition displacement tests. NMR oil saturation...

  7. Near-Infrared Surface Plasmon Resonance Measurements of Ultrathin Films. 1. Angle Shift

    E-Print Network [OSTI]

    Near-Infrared Surface Plasmon Resonance Measurements of Ultrathin Films. 1. Angle Shift and SPR-1396 The application of surface plasmon resonance (SPR) measurements to the study of ultrathin organic and inorganic. One disadvantage of using NIR wavelengths for SPR imaging is that the surface plasmon propagation

  8. Refreshing One of Several Active Representations: Behavioral and Functional Magnetic Resonance

    E-Print Network [OSTI]

    Johnson, Marcia K.

    Refreshing One of Several Active Representations: Behavioral and Functional Magnetic Resonance with this interpretation, in a functional magnetic resonance imaging study, young adults showed two areas of left they just opened the refrigerator door, telling a story multiple times to the same person, or forgetting

  9. SQUID-Detected MRI in the Limit of Zero Static Field

    SciTech Connect (OSTI)

    Kelso, Nathan Dean

    2009-12-14T23:59:59.000Z

    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.

  10. 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)

    He-3 diffusion MRI as a local in vivo morphometric tool to evaluate emphysematous rat lungs. 3D He-3 diffusion MRI as a local in vivo morphometric tool to evaluate emphysematous...

  11. High-resolution 7-Tesla fMRI of Human Hippocampal Subfields during Associative Learning.

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    fMRI in the Human Brain at 7 Tesla: Combining Reduced Field-High-resolution 7-Tesla fMRI of Human Hippocampal Subfieldsrobustly using FMRI at 7 tesla. Journal of Neuroimaging, 23(

  12. Method for resonant measurement

    DOE Patents [OSTI]

    Rhodes, G.W.; Migliori, A.; Dixon, R.D.

    1996-03-05T23:59:59.000Z

    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. 1 fig.

  13. Resonant scattering of surface plasmon polaritons by dressed quantum dots

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Hammett, Greg

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

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

    E-Print Network [OSTI]

    Hadjikhani, Nouchine

    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

  16. Efficient Concomitant and Remanence Field Artifact Reduction in Ultra-Low-Field MRI Using a

    E-Print Network [OSTI]

    Efficient Concomitant and Remanence Field Artifact Reduction in Ultra-Low-Field MRI Using: For ultra-low-field MRI, the spatial-encoding mag- netic fields generated by gradient coils can have strong to pre-polarize magnetization can improve the signal-to-noise ratio of ultra- low-field MRI. Yet

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

    E-Print Network [OSTI]

    Orchard, Jeffery J.

    : 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

  18. Fluorine-19 MRI for Visualization and Quantification of Cell Migration in a Diabetes Model

    E-Print Network [OSTI]

    Laidlaw, David

    Fluorine-19 MRI for Visualization and Quantification of Cell Migration in a Diabetes Model Mangala the nonobese dia- betic mouse, an established model of type 1 diabetes, 19F MRI data were acquired showing Med 58: 725­734, 2007. © 2007 Wiley-Liss, Inc. Key words: T cells; diabetes; MRI; cell tracking

  19. Optically Enhanced Magnetic Resonance

    E-Print Network [OSTI]

    Suter, Dieter

    , 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

  20. Proton resonance spectroscopy

    SciTech Connect (OSTI)

    Shriner, J.F. Jr.

    1991-11-01T23:59:59.000Z

    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.

  1. Double resonator cantilever accelerometer

    DOE Patents [OSTI]

    Koehler, D.R.

    1982-09-23T23:59:59.000Z

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  2. Double resonator cantilever accelerometer

    DOE Patents [OSTI]

    Koehler, Dale R. (Albuquerque, NM)

    1984-01-01T23:59:59.000Z

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  3. Voltage tunable microwave ferrite resonator

    E-Print Network [OSTI]

    Oates, Daniel E.

    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 ...

  4. Baroreflex Sensitivity during Positional Changes in Patients with Traumatic Brain Injury

    E-Print Network [OSTI]

    McNair, Norma Dianne

    2012-01-01T23:59:59.000Z

    2004). A n introduction to PET-CT imaging. RadioGraphics,D . R. (2006). PET and PET/CT imaging: What clinicians needPET), magnetic resonance imaging (MRI) and computerized tomography (CT)

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

    E-Print Network [OSTI]

    Moura, José

    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

  6. Magnetic Resonance Facility (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-03-01T23:59:59.000Z

    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.

  7. Mapping motion from 4D-MRI to 3D-CT for use in 4D dose calculations: A technical feasibility study

    SciTech Connect (OSTI)

    Boye, Dirk [Center for Proton Therapy, Paul Scherrer Institut, 5232 Villigen-PSI (Switzerland); Computer Vision Laboratory, ETH Zuerich, 8092 Zuerich (Switzerland); Lomax, Tony [Center for Proton Therapy, Paul Scherrer Institut, 5232 Villigen-PSI (Switzerland); ETH Zuerich, 8092 Zuerich (Switzerland); Knopf, Antje [Center for Proton Therapy, Paul Scherrer Institut, 5232 Villigen-PSI (Switzerland)

    2013-06-15T23:59:59.000Z

    Purpose: Target sites affected by organ motion require a time resolved (4D) dose calculation. Typical 4D dose calculations use 4D-CT as a basis. Unfortunately, 4D-CT images have the disadvantage of being a 'snap-shot' of the motion during acquisition and of assuming regularity of breathing. In addition, 4D-CT acquisitions involve a substantial additional dose burden to the patient making many, repeated 4D-CT acquisitions undesirable. Here the authors test the feasibility of an alternative approach to generate patient specific 4D-CT data sets. Methods: In this approach motion information is extracted from 4D-MRI. Simulated 4D-CT data sets [which the authors call 4D-CT(MRI)] are created by warping extracted deformation fields to a static 3D-CT data set. The employment of 4D-MRI sequences for this has the advantage that no assumptions on breathing regularity are made, irregularities in breathing can be studied and, if necessary, many repeat imaging studies (and consequently simulated 4D-CT data sets) can be performed on patients and/or volunteers. The accuracy of 4D-CT(MRI)s has been validated by 4D proton dose calculations. Our 4D dose algorithm takes into account displacements as well as deformations on the originating 4D-CT/4D-CT(MRI) by calculating the dose of each pencil beam based on an individual time stamp of when that pencil beam is applied. According to corresponding displacement and density-variation-maps the position and the water equivalent range of the dose grid points is adjusted at each time instance. Results: 4D dose distributions, using 4D-CT(MRI) data sets as input were compared to results based on a reference conventional 4D-CT data set capturing similar motion characteristics. Almost identical 4D dose distributions could be achieved, even though scanned proton beams are very sensitive to small differences in the patient geometry. In addition, 4D dose calculations have been performed on the same patient, but using 4D-CT(MRI) data sets based on variable breathing patterns to show the effect of possible irregular breathing on active scanned proton therapy. Using a 4D-CT(MRI), including motion irregularities, resulted in significantly different proton dose distributions. Conclusions: The authors have demonstrated that motion information from 4D-MRI can be used to generate realistic 4D-CT data sets on the basis of a single static 3D-CT data set. 4D-CT(MRI) presents a novel approach to test the robustness of treatment plans in the circumstance of patient motion.

  8. Peptide functionalized superparamagnetic iron oxide nanoparticles as MRI contrast agents

    E-Print Network [OSTI]

    Atalar, Ergin

    of water molecules in different tissues create distinct signal intensities that enable detection of abnormal tissues.2 MRI uses radiofrequency in a magnetic field as source of radiation which has no harmful contrast. There are numerous types of contrast agents on the market and gadolinium (Gd3+ ) based CAs

  9. Analysis of Functional MRI Timeseries Data Using Signal Processing Techniques

    E-Print Network [OSTI]

    /39 #12;fMRI: The basic idea Experimental paradigm designed to activate neuronal metabolism Changes conjugate gradient Regularization parameter A found by crossvalidation strategy S. Chen ­ Final Exam optimization with conjugate gradient 0.5 s time resolution estimate from TR = 0.5 s dataset Supertemporal

  10. Bone motion analysis from dynamic MRI: acquisition and tracking

    E-Print Network [OSTI]

    Gilles, Benjamin

    overload, impingement or femoral head instability. For both the diagnosis and the surgical planningBone motion analysis from dynamic MRI: acquisition and tracking Benjamin Gilles1 , Rosalind Perrin2 methods in order to auto- matically extract active bone kinematics from multi-slice real-time dy- namic

  11. MRI Techniques for Noninvasive Monitoring of Transplanted Organs

    E-Print Network [OSTI]

    Moura, José

    (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

  12. 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

  13. LAB #7 Resonance

    E-Print Network [OSTI]

    2005-10-09T23:59:59.000Z

    Page 1 ... We pull the box 3 cm to the right and give it an initial speed of 1 cm/sec to the left. From Newton's 2nd Law F = ma, we have seen that the motion of the spring is governed by ... of the tone. Now equation (?) becomes my ... Don't print these graphs,. 2 ... What you are observing is a phenomena call RESONANCE.

  14. Tandem resonator reflectance modulator

    DOE Patents [OSTI]

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

    1994-09-06T23:59:59.000Z

    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.

  15. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPO Website Directory PPPO WebsitePREPPROTON RESONANCE

  16. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection RadiationRecord-SettingHead5 IdleRegarding Confinement Resonances

  17. DownloadedAt:19:2615October2007 Computer Aided Surgery, January 2007; 12(1): 214

    E-Print Network [OSTI]

    Camesano, Terri

    ]. Advances in magnet design and magnetic resonance (MR) system technology, coupled with the development MRI image overlay: Application to arthrography needle insertion GREGORY S. FISCHER1 , ANTON DEGUET1, Maryland, USA (Received 30 May 2006; accepted 14 August 2006) Abstract Magnetic Resonance Imaging (MRI

  18. 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...

  19. Donna Rose Addis, TWRI, May 2004 1 ANALYSIS OF FUNCTIONAL MAGNETIC RESONANCE

    E-Print Network [OSTI]

    Addis, Donna Rose

    Donna Rose Addis, TWRI, May 2004 1 ANALYSIS OF FUNCTIONAL MAGNETIC RESONANCE IMAGING DATA USING SPM-ordinates (with signs reversed) into table as translations right, fwd and up · Check origin is at the AC · Select images (a_seg1.img, a_seg2 and brain_a.img) · Name output file (grey_clean) · Enter formula

  20. Morphology of the Small-Animal Lung Using Magnetic Resonance Microscopy

    E-Print Network [OSTI]

    Morphology of the Small-Animal Lung Using Magnetic Resonance Microscopy Laurence W. Hedlund and G motion control and animal support, the lungs of the live, small animal can be imaged. Although in vivo He, it is possible to image the tissue and gas compartments of the lung. This capability

  1. Image Fusion for MR Bias Stochastic Systems Group

    E-Print Network [OSTI]

    Willsky, Alan S.

    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

  2. MRI-compatible Haptics: Feasibility of using optical fiber Bragg grating strain-sensors to detect deflection of needles in an MRI environment

    E-Print Network [OSTI]

    Park, Yong-Lae

    MRI-compatible Haptics: Feasibility of using optical fiber Bragg grating strain-sensors to detect fiber-optic-based force and deflection sensors based on fiber Bragg grating (FBG) technology have been was developed using a single optical fiber and an MRI compatible biopsy needle (22ga x 15cm). The FBG sensor

  3. DISSIPATIVE DIVERGENCE OF RESONANT ORBITS

    SciTech Connect (OSTI)

    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

    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.

  4. Resonance test system

    DOE Patents [OSTI]

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

    2011-05-31T23:59:59.000Z

    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.

  5. Nanotube resonator devices

    DOE Patents [OSTI]

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

    2014-05-06T23:59:59.000Z

    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.

  6. Does Geometric Coupling Generates Resonances?

    E-Print Network [OSTI]

    I. C. Jardim; G. Alencar; R. R. Landim; R. N. Costa Filho

    2015-05-08T23:59:59.000Z

    Geometrical coupling in a co-dimensional one Randall-Sundrum scenario (RS) is used to study resonances of $p-$form fields. The resonances are calculated using the transfer matrix method. The model studied consider the standard RS with delta-like branes, and branes generated by kinks and domain-wall as well. The parameters are changed to control the thickness of the smooth brane. With this a very interesting pattern is found for the resonances. The geometrical coupling does not generate resonances for the reduced $p-$form in all cases considered.

  7. Cyclotron subharmonics resonant (CSR) heating

    SciTech Connect (OSTI)

    Abe, H.

    1994-01-01T23:59:59.000Z

    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.

  8. The IPNS resonance detector spectrometer

    SciTech Connect (OSTI)

    Crawford, R.K.

    1986-01-01T23:59:59.000Z

    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)

  9. Combined MRI and Fluoroscopic Guided Radiofrequency Ablation of a Renal Tumor

    SciTech Connect (OSTI)

    Fotiadis, Nikolas I., E-mail: fotiadis.nicholas@gmail.co [Royal London Hospital, Department of Interventional Radiology (United Kingdom); Sabharwal, Tarun [Guy's and St Thomas' Hospital, Interventional Radiology Department (United Kingdom); Gangi, Afshin [University Hospital of Strasbourg, Radiology Department (France); Adam, Andreas [Guy's and St Thomas' Hospital, Interventional Radiology Department (United Kingdom)

    2009-01-15T23:59:59.000Z

    Percutaneous CT- and ultrasound-guided radiofrequency ablation of renal cell carcinoma (RCC) has been shown to have very promising medium-term results. We present a unique case of recurrent RCC after partial nephrectomy in a patient with a single kidney and impaired renal function. This tumor could not be visualized either with CT or with ultrasound. A combination of magnetic resonance imaging and fluoroscopic guidance was used, to the best of our knowledge for the first time, to ablate the tumor with radiofrequency. The patient was cancer-free and off dialysis at 30-month follow up.

  10. Ion cyclotron resonance cell

    DOE Patents [OSTI]

    Weller, R.R.

    1995-02-14T23:59:59.000Z

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

  11. Ion cyclotron resonance cell

    DOE Patents [OSTI]

    Weller, Robert R. (Aiken, SC)

    1995-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Adams, Mark

    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

  13. Refraction corrected transmission ultrasound computed tomography for application in breast imaging

    E-Print Network [OSTI]

    Mueller, Klaus

    of Biomedical Engineering and Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 improvements. A final contribution is the development of a realistic anthropomorphic digital breast phantom-synthesis and 3D cone-beam imaging,4,5 the radiation dose still remains. The use of MRI technology can address

  14. Tunable dynamic Fano resonances in coupled-resonant optical waveguide

    E-Print Network [OSTI]

    Longhi, Stefano

    2015-01-01T23:59:59.000Z

    A route toward lineshape engineering of Fano resonances in photonic structures is theoretically proposed, which uses dynamic modulation of the refractive index of a microcavity. The method is exemplified by considering coupled-resonator optical waveguide systems. An exact Floquet analysis, based on coupled-mode theory, is presented. Two distinct kinds of resonances can be dynamically created, depending on whether the static structure sustains a localized mode or not. In the former case a single Fano resonance arises, which can be tuned in both frequency and line width by varying the refractive index modulation amplitude and frequency. In the latter case two resonances, in the form of narrow asymmetric dips in the transmittance, are found, which can overlap resulting in an electromagnetically-induced transparency effect.

  15. Wavelets in medical imaging

    SciTech Connect (OSTI)

    Zahra, Noor e; Sevindir, Huliya A.; Aslan, Zafar; Siddiqi, A. H. [Sharda University, SET, Department of Electronics and Communication, Knowledge Park 3rd, Gr. Noida (India); University of Kocaeli, Department of Mathematics, 41380 Kocaeli (Turkey); Istanbul Aydin University, Department of Computer Engineering, 34295 Istanbul (Turkey); Sharda University, SET, Department of Mathematics, 32-34 Knowledge Park 3rd, Greater Noida (India)

    2012-07-17T23:59:59.000Z

    The aim of this study is to provide emerging applications of wavelet methods to medical signals and images, such as electrocardiogram, electroencephalogram, functional magnetic resonance imaging, computer tomography, X-ray and mammography. Interpretation of these signals and images are quite important. Nowadays wavelet methods have a significant impact on the science of medical imaging and the diagnosis of disease and screening protocols. Based on our initial investigations, future directions include neurosurgical planning and improved assessment of risk for individual patients, improved assessment and strategies for the treatment of chronic pain, improved seizure localization, and improved understanding of the physiology of neurological disorders. We look ahead to these and other emerging applications as the benefits of this technology become incorporated into current and future patient care. In this chapter by applying Fourier transform and wavelet transform, analysis and denoising of one of the important biomedical signals like EEG is carried out. The presence of rhythm, template matching, and correlation is discussed by various method. Energy of EEG signal is used to detect seizure in an epileptic patient. We have also performed denoising of EEG signals by SWT.

  16. Heart-induced movements in the thorax as detected by MRI

    E-Print Network [OSTI]

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

    2014-01-01T23:59:59.000Z

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

  17. Calibration of fluorescence resonance energy transfer in microscopy

    DOE Patents [OSTI]

    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

    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.

  18. Calibration of fluorescence resonance energy transfer in microscopy

    DOE Patents [OSTI]

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

    2003-12-09T23:59:59.000Z

    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.

  19. Scattering resonances as viscosity limits

    E-Print Network [OSTI]

    Maciej Zworski

    2015-05-04T23:59:59.000Z

    Using the method of complex scaling we show that scattering resonances of $ - \\Delta + V $, $ V \\in L^\\infty_{\\rm{c}} ( \\mathbb R^n ) $, are limits of eigenvalues of $ - \\Delta + V - i \\epsilon x^2 $ as $ \\epsilon \\to 0+ $. That justifies a method proposed in computational chemistry and reflects a general principle for resonances in other settings.

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

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

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

  1. Transverse-longitudinal integrated resonator

    DOE Patents [OSTI]

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

    2003-03-11T23:59:59.000Z

    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.

  2. Delta connected resonant snubber circuit

    DOE Patents [OSTI]

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

    1998-01-20T23:59:59.000Z

    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.

  3. Delta connected resonant snubber circuit

    DOE Patents [OSTI]

    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

    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.

  4. Baryon Spectroscopy and Resonances

    SciTech Connect (OSTI)

    Robert Edwards

    2011-12-01T23:59:59.000Z

    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.

  5. Auxiliary resonant DC tank converter

    DOE Patents [OSTI]

    Peng, Fang Z. (Knoxville, TN)

    2000-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2014-11-26T23:59:59.000Z

    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.

  7. 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...

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

    SciTech Connect (OSTI)

    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

    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.

  9. Image alignment

    DOE Patents [OSTI]

    Dowell, Larry Jonathan

    2014-04-22T23:59:59.000Z

    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.

  10. Nuclear Resonance Fluorescence for Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian J.

    2010-01-01T23:59:59.000Z

    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.

  11. Nuclear Resonance Fluorescence for Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian

    2010-01-01T23:59:59.000Z

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

  12. Precedence of the Eye Region in Neural Processing of Faces

    E-Print Network [OSTI]

    Issa, Elias

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

  14. SU-E-J-136: Multimodality-Image-Based Target Delineation for Dose Painting of Pancreatic Cancer

    SciTech Connect (OSTI)

    Dalah, E; Paulson, E; Erickson, B; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Dose escalated RT may provide improved disease local-control for selected unresectable pancreatic cancer. Accurate delineation of the gross tumor volume (GTV) inside pancreatic head or body would allow safe dose escalation considering the tolerances of adjacent organs at risk (OAR). Here we explore the potential of multi-modality imaging (DCE-MRI, ADC-MRI, and FDG-PET) to define the GTV for dose painting of pancreatic cancer. Volumetric variations of DCE-MRI, ADC-MRI and FDG-PET defined GTVs were assessed in comparison to the findings on CT, and to pathology specimens for resectable and borderline reseactable cases of pancreatic cancer. Methods: A total of 19 representative patients with DCE-MRI, ADC-MRI and FDG-PET data were analyzed. Of these, 8 patients had pathological specimens. GTV, inside pancreatic head/neck, or body, were delineated on MRI (denoted GTVDCE, and GTVADC), on FDG-PET using SUV of 2.5, 40% SUVmax, and 50% SUVmax (denoted GTV2.5, GTV40%, and GTV50%). A Kruskal-Wallis test was used to determine whether significant differences existed between GTV volumes. Results: Significant statistical differences were found between the GTVs defined by DCE-MRI, ADC-MRI, and FDG-PET, with a mean and range of 4.73 (1.00–9.79), 14.52 (3.21–25.49), 22.04 (1.00–45.69), 19.10 (4.84–45.59), and 9.80 (0.32–35.21) cm3 (p<0.0001) for GTVDCE, GTVADC, GTV2.5, GTV40%, and GTV50%, respectively. The mean difference and range in the measurements of maximum dimension of GTVs based on DCE-MRI, ADC-MRI, SUV2.5, 40% SUVmax, and 50% SUVmax compared with pathologic specimens were ?0.84 (?2.24 to 0.9), 0.41 (?0.15 to 2.3), 0.58 (?1.41 to 3.69), 0.66 (?0.67 to 1.32), and 0.15 (?1.53 to 2.38) cm, respectively. Conclusion: Differences exists between DCE, ADC, and PET defined target volumes for RT of pancreatic cancer. Further studies combined with pathological specimens are required to identify the optimal imaging modality and/or acquisition method to define the GTV.

  15. Image Fusion and Registration a Variational Bernd Fischer1

    E-Print Network [OSTI]

    Modersitzki, Jan

    Image Fusion and Registration ­ a Variational Approach Bernd Fischer1 and Jan Modersitzki1 Institute of Mathematics, Wallstra�e 40, D-23560 L¨ubeck, Germany fischer@math.uni-luebeck.de, modersitzki, including the registration of magnetic resonance images of a female breast subject to some volume preserving

  16. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography (CT) 2 C RIS 44025 Computed Tomography (CT) Clinical Education I 3 C

  17. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology] Note: Admission to the program is required to enroll in RIS courses RIS 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography 2

  18. Prediction-Based Compression Ratio Boundaries for Medical Images

    E-Print Network [OSTI]

    Qi, Xiaojun

    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

  19. Ultrasensitive Magnetometry and Imaging with NV Diamond 

    E-Print Network [OSTI]

    Kim, Changdong

    2011-08-08T23:59:59.000Z

    NV centers in a diamond are proving themselves to be good building blocks for quantum information, electron spin resonance (ESR) imaging, and sensor applications. The key feature of the NV is that it has an electron spin that can be polarized...

  20. Multi-probe robotic positioner for cryoablation in MRI

    E-Print Network [OSTI]

    Wu, Faye Y

    2012-01-01T23:59:59.000Z

    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) ...

  1. SPIE Medical Imaging Medical Imaging

    E-Print Network [OSTI]

    Miga, Michael I.

    CT and SPECT (GE Hawkeye) SPIE Medical Imaging 2006 28 CT/PET System Combined CT and PET (Siemens Medical Imaging 2006 10 Computed Tomography (CT) 3D Tomography from multiple projections #12;6 SPIE: Scintillation Camera SPIE Medical Imaging 2006 26 PET and SPECT PET = Positron Emission Tomography SPECT

  2. Giant resonances in O-16

    E-Print Network [OSTI]

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

    2001-01-01T23:59:59.000Z

    . 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...

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Henson, Rik

    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

  5. Relationship to CCEFP strategy ! MRI Compatible Robot with an Active Cannula!

    E-Print Network [OSTI]

    Webster III, Robert James

    construction cost, zero maintenance) Test bed to the center: MRI scanners (3 at Vanderbilt and one at Georgia invasiveness. " " " " " · Constructed first (non-MRI compatible) prototype · Prototype construction underway.c.cardona@vanderbilt.edu http://research.vuse.vanderbilt.edu/MEDLab/index.htm ! Motivation! Challenges! · Must use components

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

    E-Print Network [OSTI]

    Itti, Laurent

    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

  7. MRI FINDINGS AND CLINICAL OUTCOME IN 45 DIVERS WITH SPINAL CORD DECOMPRESSION SICKNESS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 MRI FINDINGS AND CLINICAL OUTCOME IN 45 DIVERS WITH SPINAL CORD DECOMPRESSION SICKNESS Emmanuel clinical outcome in divers with spinal cord DCS. The presence of medullary compressive factors was conducted to evaluate the relationship between spinal cord lesions on MRI and clinical findings in divers

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 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

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

    E-Print Network [OSTI]

    Camesano, Terri

    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

  10. Automated Quality Assurance Routines for fMRI Data Applied to a Multicenter Study

    E-Print Network [OSTI]

    Gabrieli, John

    MRI) data and influence the sig- nificance and reliability of conclusions drawn from these data. Generally and Nichols, 2003], result reliability and variability [Casey et al., 1998; Le and Hu, 1997; Maitra et al of fMRI equipment has been considered less frequently [Simmons et al., 1999; Thulborn, 2002

  11. The neural correlates of statistical learning in a word segmentation task: An fMRI study

    E-Print Network [OSTI]

    Aslin, Richard N.

    history: Available online xxxx Keywords: fMRI Statistical learning Word segmentation Artificial language of this statistical learning mechanism in the do- main of language acquisition (see also Saffran, Aslin, & NewportThe neural correlates of statistical learning in a word segmentation task: An fMRI study Elisabeth

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

    SciTech Connect (OSTI)

    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

    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.

  13. MRI-free neuronavigation for transcranial magnetic stimulation in severe depression

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MRI-free neuronavigation for transcranial magnetic stimulation in severe depression Beno^it Comb-35043 Rennes, France d Pontchaillou Univ. Hospital, Department of Neurosurgery, F-35033 Rennes, France e Syneika, F-35000 Rennes, France Abstract. This paper presents a MRI-free neuronavigation technique

  14. Distribution of neutron resonance widths

    E-Print Network [OSTI]

    Hans A. Weidenmueller

    2011-10-28T23:59:59.000Z

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

  15. Baryon Resonances Observed at BES

    E-Print Network [OSTI]

    B. S. Zou

    2008-02-01T23:59:59.000Z

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

  16. Bayesian Experimental Design of Magnetic Resonance Imaging Sequences

    E-Print Network [OSTI]

    Seeger, Matthias

    Nickisch, Rolf Pohmann and Bernhard Sch¨olkopf Max Planck Institute for Biological Cybernetics research of the brain. Without applying any harmful ioniz- ing radiation, this technique stands out by its

  17. Enzymatically Amplified Surface Plasmon Resonance Imaging Detection of DNA by

    E-Print Network [OSTI]

    .; Majumdar, A.; Alivisatos, A. P. Anal. Chem. 2003, 75, 4766-4772. (2) Lockhart, D. J.; Winzeler, E. A

  18. Micro-machined resonator oscillator

    DOE Patents [OSTI]

    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

    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.

  19. Micro-machined resonator oscillator

    DOE Patents [OSTI]

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

    1994-08-16T23:59:59.000Z

    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.

  20. Integrating an automatic classification method into the medical image retrieval process

    E-Print Network [OSTI]

    Ruiz, Miguel E.

    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

  1. Dynamic Surface Reconstruction from 4D-MR Images Matthias Fenchel1

    E-Print Network [OSTI]

    Gumhold, Stefan

    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

  2. Image-based fluidstructure interaction model of the human mitral valve Xingshuang Ma a

    E-Print Network [OSTI]

    Luo, Xiaoyu

    Image-based fluid­structure interaction model of the human mitral valve Xingshuang Ma a , Hao Gao Available online 15 November 2012 Keywords: Human mitral valve Clinical imaging Magnetic resonance imaging Fluid­structure interaction Immersed boundary method a b s t r a c t The mitral valve (MV) is one

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

    E-Print Network [OSTI]

    Fan, Audrey Peiwen

    2014-01-01T23:59:59.000Z

    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 ...

  4. SUBSPACE MODELS FOR FUNCTIONAL MRI DATA ANALYSIS Laboratory of Mathematics in Imaging, Department of Radiology

    E-Print Network [OSTI]

    response in the time series and vice versa. Figure 1 illustrates this situation. The shaded areas indicate, Department of Radiology Brigham and Women's Hospital, Harvard Medical School ABSTRACT The models used

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Jegelka, Stefanie

    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

  7. Comparative study of imaging at 3.0 T versus 1.5 T of the knee

    E-Print Network [OSTI]

    Wong, Scott; Steinbach, Lynne; Zhao, Jian; Stehling, Christoph; Ma, C. Benjamin; Link, Thomas M.

    2009-01-01T23:59:59.000Z

    for differences in relaxation at 3.0 T. Arthroscopy wasAA. Comparison of 1.5- and 3.0-T MR imaging for evaluating11. Magee T, Williams D. 3.0-T MRI of meniscal tears. AJR Am

  8. Feasibility and electromagnetic compatibility study of the ClearPEM front-end electronics for simultaneous PET-MR imaging

    E-Print Network [OSTI]

    Dalang, Robert C.

    for simultaneous PET-MR imaging J.A. Neves a,b,c,n , R. Bugalho a,b , R. Gruetter c,d,e , A.W. Magill c,d , C Keywords: PET ClearPEM 7 Tesla MR Simultaneous PET-MRI EMI and EMC a b s t r a c t In this work we present a first feasibility study of the ClearPEM technology for simultaneous PET-MR imaging. The mutual

  9. Diffusion MRI Methods for Improved Treatment Monitoring in Breast Cancer

    E-Print Network [OSTI]

    Aliu, Sheye

    2009-01-01T23:59:59.000Z

    2.9 Breast Cancer Treatment . . . . . . . 2.9.1. Localassessing antivascular cancer treatments. Br J Radiol, 2003.imaging, for breast cancer treatment monitoring. To achieve

  10. MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization

    E-Print Network [OSTI]

    Burt, Scott R

    2008-01-01T23:59:59.000Z

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

  11. Remote NMR/MRI detection of laser polarized gases

    DOE Patents [OSTI]

    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

    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.

  12. Classical Resonances and Quantum Scarring

    E-Print Network [OSTI]

    Christopher Manderfeld

    2003-01-22T23:59:59.000Z

    We study the correspondence between phase-space localization of quantum (quasi-)energy eigenstates and classical correlation decay, given by Ruelle-Pollicott resonances of the Frobenius-Perron operator. It will be shown that scarred (quasi-)energy eigenstates are correlated: Pairs of eigenstates strongly overlap in phase space (scar in same phase-space regions) if the difference of their eigenenergies is close to the phase of a leading classical resonance. Phase-space localization of quantum states will be measured by $L^2$ norms of their Husimi functions.

  13. Ventilation-Synchronous Magnetic Resonance Microscopy of Pulmonary Structure and Ventilation in

    E-Print Network [OSTI]

    Ventilation-Synchronous Magnetic Resonance Microscopy of Pulmonary Structure and Ventilation helium (3 He) gas to acquire images that dem- onstrate pulmonary vasculature and ventilated airways of these structures relative to the less vascular surrounding tissues. A constant- flow ventilator was developed

  14. Cryoelectron-Microscopy Image Reconstruction of Symmetry Mismatches in Bacteriophage 29

    E-Print Network [OSTI]

    Baker, Timothy S.

    to the prohead, consistent with its proposed role as a component of the stator in the 29 DNA packaging motor resonance spec- troscopy. The icosahedral symmetry averaging procedures utilized in the image processing

  15. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    SciTech Connect (OSTI)

    Mukai, Y. [Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Hirori, H., E-mail: hirori@icems.kyoto-u.ac.jp [Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Yamamoto, T. [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Kageyama, H. [Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Tanaka, K., E-mail: kochan@scphys.kyoto-u.ac.jp [Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan)

    2014-07-14T23:59:59.000Z

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO{sub 3} crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

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

    E-Print Network [OSTI]

    Piatkowski, Jakub Przemyslaw

    2014-06-27T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Iwasa, Yukikazu

    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 ...

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

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Glover, Gary H.

    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

  20. Automated perfusion-weighted MRI metrics via localized arterial input functions

    E-Print Network [OSTI]

    Lorenz, Cory, 1981-

    2004-01-01T23:59:59.000Z

    This thesis describes and validates a new method for calculating perfusion-weighted MRI (PWI) metrics, a non-invasive technique for calculating cerebral blood flow by tracking a bolus of contrast agent. Past methods to do ...

  1. 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

  2. Department of Bioengineering Spring 2013 MRI Compatible Gustometer for Childhood Obesity Research

    E-Print Network [OSTI]

    Demirel, Melik C.

    PENNSTATE Department of Bioengineering Spring 2013 MRI Compatible Gustometer for Childhood Obesity or obesity. A need exists to better understand the neurological perception of taste in order to create better

  3. Undersampling to accelerate time-resolved MRI velocity measurement of carotid blood flow 

    E-Print Network [OSTI]

    Tao, Yuehui

    2009-01-01T23:59:59.000Z

    Time-resolved velocity information of carotid blood flow can be used to estimate haemodynamic conditions associated with carotid artery disease leading to stroke. MRI provides high-resolution measurement of such information ...

  4. Orbital Resonance and Solar Cycles

    E-Print Network [OSTI]

    P. A. Semi

    2009-03-29T23:59:59.000Z

    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.

  5. NANOSCALE OPTICAL COMPUTING USING RESONANCE ENERGY

    E-Print Network [OSTI]

    Lebeck, Alvin R.

    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

  6. Piezoelectric MEMS resonator characterization and filter design

    E-Print Network [OSTI]

    Kang, Joung-Mo, 1978-

    2004-01-01T23:59:59.000Z

    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 ...

  7. Scientific innovation and resonance ionization spectroscopy

    SciTech Connect (OSTI)

    Richmond, C.R.

    1981-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Gao, Jinming

    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

  9. High-frequency microstrip cross resonators for circular polarization electron paramagnetic resonance spectroscopy

    E-Print Network [OSTI]

    del Barco, Enrique

    resonators, designed to match the 50 impedance of the lines on a high dielectric constant GaAs substrate excitation at the center of the cross resonator. The third output port is used to measure the transmitted resonator, composed of two half- wavelength microstrip line resonators which allow an in situ and all

  10. H Loop shaping control for PLL-based mechanical resonance tracking in NEMS resonant mass sensors

    E-Print Network [OSTI]

    Boyer, Edmond

    problem that rejects the disturbance described by the resonance frequency shift, attenuates the phase the measurement scheme to a disturbance rejection control issue which considers the resonance frequency variation--A simple dynamic detection of the resonance frequency shift in NEMS resonant mass sensors is described

  11. Methods for magnetic resonance analysis using magic angle technique

    DOE Patents [OSTI]

    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

    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.

  12. Nonlinear optics via double dark resonances 

    E-Print Network [OSTI]

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

    2003-01-01T23:59:59.000Z

    frequency ~RF! field. We observe two sharp resonances at shifted frequencies. We also 1050-2947/2003/68~6!/063801~7!/$20.00 68 063801- e dark resonances ,4,3 G. R. Welch,3 and M. D. Lukin5 , Storrs, Connecticut 06269, USA Moscow 117924, Russia y... 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...

  13. Extraordinary acoustic transmission mediated by Helmholtz resonators

    SciTech Connect (OSTI)

    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

    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.

  14. 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)

    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

    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.

  15. Resonant Relaxation in Electroweak Baryogenesis

    E-Print Network [OSTI]

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

    2004-12-23T23:59:59.000Z

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

  16. Resonant Relaxation in Electroweak Baryogenesis

    E-Print Network [OSTI]

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

    2004-01-01T23:59:59.000Z

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

  17. Unstable resonator cavity semiconductor lasers

    SciTech Connect (OSTI)

    Salzman, J.; Venkatesan, T.; Lang, R.; Mittelstein, M.; Yariv, A.

    1985-02-01T23:59:59.000Z

    GaAs heterostructure lasers with unstable resonator cavities were demonstrated for the first time with both curved mirrors fabricated by etching. Typical output powers of 0.35 W were observed in a stable, highly coherent lateral mode. The laser operated stably in a single longitudinal mode over a large range of injection currents. The external quantum efficiency was 70% of that of a similar laser with both mirror facets cleaved implying good output coupling of the energy from the entire region.

  18. Ring resonant cavities for spectroscopy

    DOE Patents [OSTI]

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

    1999-06-15T23:59:59.000Z

    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.

  19. Resonance ionization for analytical spectroscopy

    DOE Patents [OSTI]

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

    1976-01-01T23:59:59.000Z

    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.

  20. Hadronic Resonances from Lattice QCD

    SciTech Connect (OSTI)

    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

    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.

  1. Hadronic Resonances from Lattice QCD

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    in a group of subjects at both 7 Tesla and 4 Telsa[1]. Functional MRI data were collected with multiple TEs

  3. Indocyanine Green Loaded Nanoconstructs for Optical Imaging and Phototherapeutic Applications

    E-Print Network [OSTI]

    Bahmani, Baharak

    2013-01-01T23:59:59.000Z

    in diameter) utilizing CT, CT/PET, MRI or visual inspectionmethods including CT, CT/PET, MRI or visual inspection won’t

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

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    index that corresponds to increased vascu- lar density [32]. DOSI scanning is performed without compression

  5. 1248 IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 47, NO. 9, SEPTEMBER 2000 Paired MEG Data Set Source Localization Using

    E-Print Network [OSTI]

    Leahy, Richard M.

    . Huang is with the University of New Mexico, Albuquerque, NM 87131 USA (e-mail: mhuang@UNM.Edu). *R. M-9294(00)08014-9. (PET) and functional magnetic resonance imaging (fMRI) acti- vation studies, differences between

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

    E-Print Network [OSTI]

    Pak, Hyuk Kyu

    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

  7. Hyperspectral Imaging or Imaging Spectroscopy

    E-Print Network [OSTI]

    Gilbes, Fernando

    (nm) Cosmic Rays Gamma Rays X Rays Microwaves (Radar) Radio & Television WavesUV 105 106 107 108 109 the image cube by scanning through it. The conventional methods are whiskbroom (a), filter/Fourier transform Optics Scene FOVx X-Dimension Scanning Mechanism Focusing Optics #12;Whiskbroom Sensor Accumulation

  8. SU-E-J-153: MRI Based, Daily Adaptive Radiotherapy for Rectal Cancer: Contour Adaptation

    SciTech Connect (OSTI)

    Kleijnen, J; Burbach, M; Verbraeken, T; Weggers, R; Zoetelief, A; Reerink, O; Lagendijk, J; Raaymakers, B; Asselen, B [University Medical Center Utrecht, Utrecht (Netherlands)

    2014-06-01T23:59:59.000Z

    Purpose: A major hurdle in adaptive radiotherapy is the adaptation of the planning MRI's delineations to the daily anatomy. We therefore investigate the accuracy and time needed for online clinical target volume (CTV) adaptation by radiation therapists (RTT), to be used in MRI-guided adaptive treatments on a MRI-Linac (MRL). Methods: Sixteen patients, diagnosed with early stage rectal cancer, underwent a T2-weighted MRI prior to each fraction of short-course radiotherapy, resulting in 4–5 scans per patient. On these scans, the CTV was delineated according to guidelines by an experienced radiation oncologist (RO) and considered to be the gold standard. For each patient, the first MRI was considered as the planning MRI and matched on bony anatomy to the 3–4 daily MRIs. The planning MRI's CTV delineation was rigidly propagated to the daily MRI scans as a proposal for adaptation. Three RTTs in training started the adaptation of the CTV conform guidelines, after a two hour training lecture and a two patient (n=7) training set. To assess the inter-therapist variation, all three RTTs altered delineations of 3 patients (n=12). One RTT altered the CTV delineations (n=53) of the remaining 11 patients. Time needed for adaptation of the CTV to guidelines was registered.As a measure of agreement, the conformity index (CI) was determined between the RTTs' delineations as a group. Dice similarity coefficients were determined between delineations of the RTT and the RO. Results: We found good agreement between RTTs' and RO's delineations (average Dice=0.91, SD=0.03). Furthermore, the inter-observer agreement between the RTTs was high (average CI=0.94, SD=0.02). Adaptation time reduced from 10:33 min (SD= 3:46) to 2:56 min (SD=1:06) between the first and last ten delineations, respectively. Conclusion: Daily CTV adaptation by RTTs, seems a feasible and safe way to introduce daily, online MRI-based plan adaptation for a MRL.

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

    SciTech Connect (OSTI)

    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

    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.

  10. Imaging bolometer

    DOE Patents [OSTI]

    Wurden, Glen A. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    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.

  11. Imaging bolometer

    DOE Patents [OSTI]

    Wurden, G.A.

    1999-01-19T23:59:59.000Z

    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.

  12. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography 2 C RIS 44025 Computed Tomography Clinical Education I 3 C RIS 44030

  13. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography (CT) 2 C RIS 44025 Computed Tomography (CT) Clinical Education I 3 C

  14. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Foundenhancer activity than FINAL Report/Product Number(s)m

  15. System and method for regulating resonant inverters

    DOE Patents [OSTI]

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

    2007-08-28T23:59:59.000Z

    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.

  16. Optomechanical-like coupling between superconducting resonators

    E-Print Network [OSTI]

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

    2014-03-18T23:59:59.000Z

    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.

  17. Seeking the neural basis of grammar : English noun and verb morphological processing investigated with rapid event-related fMRI and intracortical electrophysiology

    E-Print Network [OSTI]

    Sahin, Nedim T. (Nedim Turan), 1975-

    2003-01-01T23:59:59.000Z

    (cont.) the functionality of the fMRI data analysis and visualization tools used at Massachusetts General Hospital. I analyze and interpret an 18-subject fMRI experiment I ran using the new task design and software tools. ...

  18. Paramagnetic resonance at low fields

    E-Print Network [OSTI]

    Becker, Stewart

    1954-01-01T23:59:59.000Z

    ....................................... 88 TABLE OF CONTENTS LIST OF FIGURES FIGURE PAGE II-l. Apparatus for Observing Paramagnetic Resonance . . . 5 II-2. Splitting of the Energy Level in the Presence of a Steady Magnetic Field Ho . . . .............. 9 II-3. Molecular Structure... Th experiences a torque expressed by A A A . . L - X H (2) Newton's Law for rotational motion is * dP L ? XT ? (3)dt A combination of equations (l), (2) and (3 ) gives 9 5 k A which is the equation of motion for a vector P of constant...

  19. Acoustic resonance spectroscopy in nuclear safeguards

    SciTech Connect (OSTI)

    Olinger, C.T.; Lyon, M.J.; Stanbro, W.D.; Mullen, M.F.; Sinha, D.N.

    1993-08-01T23:59:59.000Z

    Objects resonate at specific frequencies when mechanically excited. The specific resonance frequencies are a function of shape, size, material of construction, and contents of the object. This paper discusses the use of acoustic resonance spectroscopy (ARS) to monitor containers and detect tampering. Evaluation of this technique is based on simulated storage simulations. Although these simulations show promise for this application of ARS, final evaluation will require actual field testing.

  20. Acoustic resonance spectroscopy in nuclear safeguards

    SciTech Connect (OSTI)

    Olinger, C.T.; Lyon, M.J.; Stanbro, W.D.; Mullen, M.F.; Sinha, D.N. [Los Alamos National Lab., NM (United States)

    1993-12-31T23:59:59.000Z

    Objects resonate at specific frequencies when mechanically excited. The specific resonance frequencies are a function of shape, size, material of construction, and contents of the object. This paper discusses the use of acoustic resonance spectroscopy (ARS) to monitor containers and detect tampering. Evaluation of this technique is based on simulated storage situations. Although these simulations show promise for this application of ARS, final evaluation will require actual field testing.