Abstract: First, benchmark data are collected on two thin slices of an object to get measured k-space trajectories. To find delays on different physical gradients, the root mean square error between estimated and measured k-space trajectories is minimized for different delays. To reduce the error further, an eddy current compensation is introduced along each physical gradient axis. A more accurate estimation of the k-space trajectory can be obtained to image the object.
Type:
Grant
Filed:
February 25, 2008
Date of Patent:
February 15, 2011
Assignee:
University of Virginia Patent Foundation
Abstract: A system and method for MR imaging includes a computer programmed to determine first and second view-ordering sequences. The first and second view-ordering sequences comprise values corresponding to respective views of first and second k-space data sets, respectively, wherein the values corresponding to a central view of each the first and second k-space data sets are positioned such that acquisition of k-space data in each central view is acquired from a first and second anatomical region, respectively, as a contrast agent passes therethrough. The positions of the values corresponding to the central views of the first and second k-space data sets within the respective sequences are different. The computer is further programmed to acquire MR data according to the first and second view-ordering sequences over a series of cardiac cycles to fill data in the first and second k-space data sets, respectively.
Type:
Grant
Filed:
June 4, 2008
Date of Patent:
February 1, 2011
Assignees:
General Electric Company, The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Massachusetts General Hospital
Inventors:
Maggie M. Fung, Ehud J. Schmidt, Godtfred Holmvang, Vincent B. Ho
Abstract: A method for fat-suppressed imaging is disclosed. Such a method may include storing a first spectral component of an echo signal formed at TR/2 from a sample, suppressing a second spectral component of the echo signal at TR/2, re-exciting the stored spectral component after suppressing the second spectral component, and producing an image of the sample based on the re-excited stored spectral component.
Type:
Grant
Filed:
May 21, 2007
Date of Patent:
February 1, 2011
Assignee:
The United States of America as represented by the Department of Health and Human Services
Inventors:
John Andrew Derbyshire, Daniel Alfredo Herzka, Elliot R. McVeigh
Abstract: A magnetic resonance imaging apparatus includes an imaging unit which applies a labeling pulse to invert a spin included in a labeling region within part of a imaging region and then collects a echo signal from a time point when an inversion time has passed from the application of the labeling pulse, and a control unit, the control unit controlling the imaging unit so that the echo signal in the imaging region is collected a plurality of times with variations in the inversion time, the control unit also controlling the imaging unit so that a time ranging from a reference time point within a biological signal obtained from a subject to the application of the labeling pulse is a time determined in accordance with the inversion time.
Type:
Grant
Filed:
September 10, 2007
Date of Patent:
February 1, 2011
Assignees:
Tokai University Educational System, Toshiba Medical Systems Corporation
Abstract: A volume coil for a magnetic resonance imaging system is composed of a number of coil units. In the coil, there are overlapped parts between two adjacent ones of the coil units for eliminating coupling between these two adjacent coil units. Two next-adjacent ones of the coil units, which are separated from each other by one coil unit, are each provided with an inductor, and these two inductors are coupled with each other for eliminating coupling between these two next-adjacent coil units. All coil units are collected on one axial end face of the coil. Two coil units in the coil that are neither adjacent coil units nor next-adjacent coil units are connected with each other on the end face by a capacitance circuit or a inductance circuit for eliminating the coupling between these two coil units that are neither adjacent coil units nor next-adjacent coil units.
Type:
Grant
Filed:
February 27, 2009
Date of Patent:
January 25, 2011
Assignee:
Siemens Aktiengesellschaft
Inventors:
Hua Bin Zhu, Yan Hong Chen, Hai Ning Wang, Jian Min Wang
Abstract: A knee coil for magnetic resonance imaging has a first, a second and a third array of coil units, the first, second and third array of coil units forming a cylindrical shape, and being adjacent to each other in the direction perpendicular to the bottom of the cylindrical shape. Each of the first array of coil units and the third array of coil units is composed of two saddle coil units, and the second array of coil units is composed of six coil units, which are successively adjacent to each other in the direction of circumference of the cylinder side face. With a simple design and at a low cost, this knee coil ensures good capacity of parallel acquisition in all directions in the course of scanning while reducing the number of channels.
Abstract: An NMR probe is offered which enables a 1H/19F compatibility mode having a sample coil, a hollow tubular body, and two rod electrodes disposed inside the tubular body substantially in a parallel relationship to each other. The tubular body is formed by a conductive wall at ground potential. An RF input-output portion corresponding to the resonant frequency of 1H nucleus is connected with the one end of the coil via a tuning and matching device. Another RF input-output port corresponding to the resonant frequency of 19F nucleus is connected with an end of the coil via another tuning and matching device.
Abstract: An apparatus and a method is provided based on the Magnetic Resonance techniques to analyze and measure a uni- and/or a bi-directional flow regime of multiphase fluids in a transport and production conduct, in real time and flow-rates, based on a magnetic resonance analytical module, two magnetic prepolarization modules of variable effective length and a control computer of data acquisition and transfer, all associated to each other.
Type:
Grant
Filed:
November 27, 2007
Date of Patent:
January 18, 2011
Assignee:
Shell Oil Company
Inventors:
Daniel Pusiol, Mariela Carpinella, Gabriela Albert, Tristan Osan, Juan Manuel Olle, John Justin Freeman, Matthias Appel, Irene Silvina Lopez Gamundi Espejo
Abstract: An apparatus for controlling a temperature of a warm bore of a superconducting magnet in a magnetic resonance imaging (MRI) system includes a cooling tube that is mounted on a surface of the warm bore and is configured to transport a coolant. A chiller is coupled to the cooling tube and is configured to provide the coolant to the cooling tube. A controller is coupled to the chiller and is configured to provide a control signal to the chiller to control a temperature of the coolant.
Abstract: A miniaturized instrument and method of using electron spin resonance spectrometry for measuring the degradation of lubricating fluids, and the like, that includes continuously passing a sample of such fluid through a resonating RF microwave cavity resonator during the application therethrough of a uniform slowly varying uniform magnetic field that is rapidly modulated and measuring the resulting phase modulation or amplitude modulation thereof to derive an electron spin resonance signal that directly senses the molecular changes in the fluid sample resulting from fluid degradation during operation of the vehicle, such as peroxy radicals in vehicle engine oil and the like.
Abstract: Embodiments of the present invention relate to systems and methods for calibrating functional magnetic resonance imaging of living tissue. For example, a calibration method includes providing a contrast signal simulation device configured for generating one or more pre-determined contrast simulation signals selected from a group consisting of BOLD and BOSS contrast simulation signals that simulate at least one contrast signal generated by living tissue of a subject and positioning the contrast signal simulation device adjacent to the subject. The method includes using an imaging instrument to take first and second data sets from the subject's tissue while the contrast signal simulation device is disposed adjacent to the subject and while generating and not generating the one or more pre-determined contrast simulation signals, respectively.
Type:
Grant
Filed:
July 9, 2008
Date of Patent:
January 4, 2011
Assignee:
University of Florida Research Foundation, Inc.
Abstract: A magnetic resonance imaging apparatus generates slice images by repeating, for a plurality of consecutive repetition times, transmitting an RF pulse to a plurality of slices and scanning the slices to acquire magnetic resonance signals generated therein, in multi-slice acquisition covering the sequential slices, the sequential slices including at least a first slice, a second slice, a third slice, and a fourth slice. In the first, second, third, and fourth slices, phases of the RF pulses are alternately reversed every consecutive repetition time, and the RF pulses are transmitted to the first, second, third, and fourth slices such that the phases of the RF pulses transmitted to the first and third slices are reversed from each other in each consecutive repetition time and such that the phases of the RF pulses transmitted to the second and fourth slices are reversed from each other in each consecutive repetition time.
Type:
Grant
Filed:
January 7, 2009
Date of Patent:
December 28, 2010
Assignee:
GE Medical Systems Global Technology Company, LLC
Abstract: The present invention provides a magnetic resonance imaging system capable of performing spectrum measurement even when a magnetic resonant frequency changes during MRS measurement. A time-varying rate of a water magnetic resonant frequency is measured in advance before the MRS measurement. The amount of change in water magnetic resonant frequency during the MRS measurement is predicted from the measured time-varying rate. With the predicted value as the reference, a transmission frequency of an RF magnetic field irradiated in a signal suppression pulse sequence, a transmission frequency of an RF magnetic field for excitation and inversion and a received frequency at the detection of a magnetic resonance signal in a sequence of the MRS measurement are respectively set. A high-precision spectrum measurement is hence enabled.
Abstract: In an arrangement to correct eddy currents in a gradient coil of a magnetic resonance apparatus, the gradient coil having a primary gradient sub-coil and a secondary gradient sub-coil connected in series with the primary gradient sub-coil, the secondary gradient sub-coil is coupled with the primary gradient sub-coil such that the same magnitude gradient current flows through both (but in different directions) in order to compensate for magnetic field distortions of the primary gradient sub-coil. The primary gradient sub-coil has a first impedance while the secondary gradient sub-coil has a second impedance. A tuning impedance is connected in parallel with at least one of the two impedances.
Abstract: In a method and a corresponding control device for automatic position determination in at least one spatial direction of at least two acquisition devices, wherein more acquisition devices than acquisition channels are present, a position measurement for one of the acquisition devices is implemented with an acquisition channel in a first step and a position measurement for another of the acquisition devices with the same acquisition channel is implemented in a second step. The position of the respective acquisition devices is determined based on these position measurements.
Abstract: A magnetic resonance diagnosing apparatus includes an imaging unit which images each slice image of a subject in relation to a plurality of different imaging slices, a measurement unit which measures a magnetic resonance spectrum of the subject in relation to a measurement slice, a selection unit which selects slice images corresponding to one or more imaging slices which at least partially overlap the measurement slice from the plurality of slice images, and a creation unit which creates a display image which simultaneously shows the selected one or more slice images and the spectral image.
Type:
Grant
Filed:
March 3, 2008
Date of Patent:
December 7, 2010
Assignees:
Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
Abstract: In a method for controlling a magnetic resonance system with a number of individually controllable transmission channels, a limited number of antenna control parameter sets are available that are associated with respective different examination situation classes that are defined with regard to specific examination situation parameters. The antenna control parameter sets include, for each of the transmission channels, a channel value or a channel value combination with which a relative amplitude and a relative phase of a radio-frequency signal emitted via the appertaining transmission channel are defined. Respective current examination situation parameter values to be associated with the examination situation parameters for the magnetic resonance measurement to be implemented are then detected and one of the examination situation classes is selected based on this.
Abstract: A system and method of phase contrast imaging includes a system control programmed to acquire a first set of data and a second set of data via the RF coil assembly during a scan and acquire a third set of data and a fourth set of data via the plurality of magnetic field monitoring devices during the scan. A first single data set from the first and third sets of data is formed, and a second single data set from the second and fourth sets of data is formed. The system control is also programmed to reconstruct a phase contrast image based on the first and second single data sets to correct for spatially-dependent background phase variations.
Type:
Grant
Filed:
April 11, 2008
Date of Patent:
December 7, 2010
Assignee:
General Electric Company
Inventors:
Florian Wiesinger, Thomas K. F. Foo, Mika Vogel, Dirk Lange
Abstract: A system and method for simultaneously acquiring PET and MR data from a subject of interest with a hybrid PET-MR scanner includes monitoring transmission times of RF and gradient coils of the MR equipment and blanking segments of the PET data stream accordingly. By excluding PET data acquired during active MR transmissions, the remaining PET data used for image reconstruction will provide improved PET image quality.
Type:
Grant
Filed:
January 10, 2007
Date of Patent:
December 7, 2010
Assignee:
General Electric Company
Inventors:
Robert H. Haworth, Steven G. Ross, Charles W. Stearns, Jason A. Polzin, Alexander Ganin
Abstract: A magnetic resonance imaging apparatus includes a generation unit configured to generate a magnetic field, a reconstruction unit configured to reconstruct an image for a subject on the basis of a magnetic resonance signal radiated from the subject in the magnetic field, a presumption unit configured to presume a distribution of an image quality deterioration degree occurring in the image on the basis of a precision at which the generation unit generates the magnetic field, and a creation unit configured to create a display image showing the distribution of the image quality deterioration degree on the image.
Type:
Grant
Filed:
February 20, 2009
Date of Patent:
November 30, 2010
Assignees:
Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation