Abstract: Support information including at least a setting image showing a present configuration of placing a patient on a bed and a present configuration of placing an RF coil for the patient is displayed. As necessary, the support information is displayed while including the position of a virtual magnetic field center corresponding to the position of a magnetic field center in the case of moving the bed into a gantry. The displayed support information is stored at a predetermined timing and can be read arbitrarily. By observing the displayed support information, the operator can promptly and easily determine whether the placement configuration of the patient and that of the RF coil at present are proper or not, and can accurately correct the placement configuration of the patient or the RF coil.
Type:
Grant
Filed:
July 15, 2008
Date of Patent:
November 3, 2009
Assignees:
Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
Abstract: A method in the form of a sequence for magnetic resonance imaging with which image data of a subject to be examined are acquired and with which signals of nuclear spins of a specific type are suppressed, includes the steps of (a) application of a suppression module to suppress signals of the nuclear spins of the specific type, (b) application of an acquisition module after a wait time to acquire measurement data, (c) repetition of the steps (a) and (b) one or more times, respectively after a repetition time and, (d) before the steps (a), (b) and (c), application of a spin preparation module that shifts a magnetization of the nuclear spins of the specific type into a steady state condition that is maintained through the application of the subsequent steps (a), (b) and (c).
Abstract: A method of operating a magnetic resonance imaging (MRI) system is described. A magnetic element in an implanted medical device is demagnetized by exposing it to an external demagnetizing magnetic field. Magnetic resonance imaging of the patient is performed. Then the magnetic element is remagnetized without removing it from the implanted medical device by exposing the magnetic element to an external remagnetizing magnetic field.
Abstract: A method for homogenizing a static magnetic field with a magnetic field distribution B0(r) for nuclear magnetic resonance spectroscopy by adjusting the currents Ci through the shim coils, thus creating spatial field distributions Ci·Si(r), where r stands for one, two, or three of the spatial dimensions x, y, and z, and said magnetic field distribution B0(r) has only a field component along z, in a working volume of a magnetic resonance apparatus with one or more radio frequency (=RF) coils (5) for inducing RF pulses and receiving RF signals within a working volume, said RF coils having a spatial sensitivity distribution of magnitudes B1k(r), and with shim coils (6) for homogenizing the magnetic field within the working volume, said shim coils (6) being characterized by their magnetic field distributions per unit current Si(r) and having components only along z, includes the following steps: (a) Mapping the magnetic field distribution B0(r) of the main magnetic field, (b) calculating a simulated spectrum IS
Type:
Grant
Filed:
October 18, 2007
Date of Patent:
October 20, 2009
Assignee:
Bruker BioSpin AG
Inventors:
Markus Weiger, Michael Fey, Thomas Speck
Abstract: A method for visualizing diffusion-tensor magnetic resonance images, including the steps of providing a diffusion-tensor magnetic resonance image (DT-MRI) volume, positioning and orienting a virtual camera for rendering the volume, the camera having an image plane, the camera's orientation being defined by its look, right and up vectors, associating a billboard with each voxel, each the billboard being parallel with the image plane of the camera, where the look, right and up vectors are used to orient each the billboard, applying a texture to each billboard, each the texture being transformed by the inverse of the diffusion tensor associated with the voxel to which the billboard is associated, and rendering the volume by rendering each visible billboard in the image volume, where a 2-dimensional (2D) visualization of the DT-MRI is produced.
Abstract: An MRI imaging coil assembly includes a primary external MRI imaging coil and a secondary external MRI imaging coil positioned proximate to the primary MRI imaging coil. The primary imaging coil has a plurality of spaced-apart RF coils and is configured to surround at least a portion of a patient. The secondary imaging coil has at least one RF coil and cooperates with the primary imaging coil to provide MRI signals to an MRI scanner. The secondary imaging coil can be movably positioned relative to the primary imaging coil. The secondary imaging coil can be movably secured to the primary imaging coil or to a patient support surface.
Type:
Grant
Filed:
September 24, 2008
Date of Patent:
October 13, 2009
Assignee:
SurgiVision, Inc.
Inventors:
Peter Piferi, Christopher Keidl, David Peterson
Abstract: A plurality of linear current elements are configured about a specimen to be imaged. A current in each current element is controlled independent of a current in other current elements to select a gradient and to provide radio frequency shimming. Each current element is driven by a separate channel of a transmitter and connected to a separate channel of a multi-channel receiver. The impedance, and therefore, the current, in each current element is controlled mechanically or electrically.
Type:
Grant
Filed:
April 21, 2003
Date of Patent:
October 6, 2009
Assignee:
Regents of the University of Minnesota
Inventors:
John Thomas Vaughan, Jr., Kamil Ugurbil, Gregor Adriany
Abstract: A tomographic measuring system is disclosed with at least two tomographic measuring devices, of which at least a first can interfere with a second in a manner disadvantageous for conducting measurements. In at least one embodiment, the system includes a switching-off mechanism at least in the first measuring device; and at least one external connection to the first measuring device for transmitting a switching-off signal to the switching-off mechanism, if the second measuring device is conducting a measurement or will conduct one. A method for conducting measurements with an appropriate tomographic measuring system is also disclosed.
Abstract: According to some embodiments, a synthetic nuclear magnetic resonance (NMR) reference signal is injected into the receive path of an NMR spectrometer, after the NMR probe and before the receive amplifier. The synthetic signal is generated using a transmit path for the same channel or for a different channel than the reference signal detection channel. The reference signal is coupled from a transmit-path reference signal coupler situated before a transmit amplifier to a receive-path reference signal coupler situated between the probe and the receive amplifier. The reference signal couplers may include passive directional couplers and/or active switches. The synthetic signal samples the receive path of the system but is not substantially affected by intra-probe interactions. Using a well-defined existing NMR channel to generate the reference signal allows superior control of reference signal characteristics, and does not require a dedicated spare channel for the reference signal.
Type:
Grant
Filed:
March 7, 2008
Date of Patent:
September 29, 2009
Assignee:
Varian, Inc.
Inventors:
Knut G. Mehr, Daina Zofija Avizonis, John Mark Dixon, Boban Kuriakose John
Abstract: Variable-density (VD), sequentially-interleaved sampling of k-space coupled with the acquisition of reference frames of data is carried out to improve spatiotemporal resolution, image quality, and signal-to-noise ratio (SNR) of dynamic images. In one example, ktSENSE is implemented with a non-static regularization image, such as that provided by RIGR or similar technique, to acquire and reconstruct dynamic images. The integration of ktSENSE and RIGR, for example, provides dynamic images with higher spatiotemporal resolution and lower image artifacts compared to dynamic images acquired and reconstructed using ktSENSE alone.
Abstract: A magnetic resonance imaging apparatus includes: a static magnetic field generating unit which generates a static magnetic field, a measuring unit which measures the strength distribution characteristic of the static magnetic field, a determination unit which determines correction amounts for first- to nth-order (n is a natural number of more than one) components of the strength distribution characteristic of the static magnetic field by fixing the correction amount for at least one specific component which are part of the first- to nth-order components at a predetermined amount and determining the correction amounts for other components than the specific component on the basis of the strength distribution characteristic, and a correction magnetic field generating unit which generates correction magnetic fields to correct the static magnetic field on the basis of the correction amounts.
Type:
Grant
Filed:
March 30, 2007
Date of Patent:
September 22, 2009
Assignees:
Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
Abstract: A high frequency cavity resonator for nuclear magnetic resonance, including: a set of transmission lines; and a shield surrounding these transmission lines, wherein each of these transmission lines includes a straight bar which is divided into elongated cylindrical segments, these segments being or being made electrically conducting, the bar being provided with thin solid dielectric elements inserted between the segments.
Type:
Grant
Filed:
February 4, 2005
Date of Patent:
September 22, 2009
Assignee:
Commissariat a l'Energie Atomique
Inventors:
Michel Luong, Xavier Hanus, Michel Desmons, Franck Lethimonier, Eric Giacomini
Abstract: A method of and miniaturized apparatus adapted for in-situ measurement of degradation of automotive fluids and the like by micro-electron spin resonance (ESR) spectrometry, wherein the use of a modulated constant magnetic field in an RF resonating variable frequency microwave cavity resonator through which a fluid sample is passed, enables direct detection of molecular changes in such fluid sample resulting from fluid degradation during use.
Abstract: In a method for determining an absolute number of electron spins in an extended sample (3) with the assistance of an apparatus for measuring magnetic resonance, the extended sample (3) is disposed within a measurement volume (2) of a radiofrequency RF resonator (1) of the apparatus during an electron spin resonance measurement (ESR).
Abstract: In an arrangement for conversion of an analog acquisition signal of an acquisition coil of a magnetic resonance apparatus into a digital signal, the output of the acquisition coil is connected with a low-noise amplifier such that the analog acquisition signal from the acquisition coil arrives at the amplifier. The amplifier is connected at the output side with a device for analog-digital conversion, such that the analog acquisition signal arrives at the device for analog-digital conversion as an amplified acquisition signal for analog-digital conversion. The device for analog-digital conversion is designed as a delta-sigma modulator that forms a digital data stream with a width of one bit from the amplified acquisition signal.
Abstract: The invention concerns an arrangement for magnetic field measurement of a measurement object (in particular a gradient coil in a magnetic resonance apparatus) with a magnetic field sensor that is designed to measure a magnetic field of the measurement object and with a measurement mechanism on which the magnetic field sensor is arranged at a first position. The measurement object has detectable reference points that can be used for calibration of a spatial position of a position sensor. The calibrated position sensor is arranged at a second position of the measurement mechanism, such that, with the first position and the second position, a spatial position relative to the measurement object can be associated with each magnetic field strength that is measured by the magnetic field sensor.
Abstract: A method for generating a magnetic resonance image of a moving subject comprises tracking the position and orientation of a target volume and modifying acquisition parameters for each line of k-space data using current position and orientation information. By approximating the target volume as a rigid object, the current position and orientation is translated into an offset vector and a rotation which are used to modify the acquisition of each k-space line individually. The offset along a slice direction is compensated for by changing the transmit frequency. The offset along the frequency-encoding direction is compensated for by changing the frequency of a reference demodulation signal. The offset along the phase direction is compensated for by changing the phase of a reference demodulation signal, or by adding a phase into the line of k-space data after acquisition.
Type:
Grant
Filed:
October 9, 2007
Date of Patent:
August 11, 2009
Assignee:
GE Medical Systems Global Technology Company LLC.
Abstract: A radiofrequency (RF) resonator for magnetic resonance analysis, the RF resonator comprising: (a) at least two conductive elements, each having a first curvature along a direction perpendicular to a longitudinal axis, the at least two conductive elements being spaced along the longitudinal axis, so that when an RF current flows within the at least two conductive elements in a direction of the longitudinal axis, a substantially homogenous RF magnetic field, directed perpendicular to the longitudinal axis, is produced in a volume defined between the at least two conductive elements.
Type:
Grant
Filed:
August 30, 2007
Date of Patent:
August 11, 2009
Assignee:
Ramot at Tel Aviv University Ltd.
Inventors:
Arnon Neufeld, Menahem Levin, Gil Navon
Abstract: A method of removing noise while preserving signal in nuclear magnetic resonance images combines steps of performing a magnitude threshold filter and performing a phase threshold filter on the image data. Preferably, a magnitude and phase connectivity algorithm is applied to pixels that fail to meet either the magnitude or phase thresholds.
Abstract: A system and method for the monitoring and treating of a coolant in a cooling system of an MRI system includes a deionization kit connectable to the cooling system of the MRI system. The deionization kit receives coolant from the cooling system to deionize the coolant and forms a closed-loop system with the cooling system when connected thereto. The deionization kit thus allows for unimpeded circulation of the coolant through the deionization kit and the cooling system. Accordingly, the MRI system may remain in operation and be used to perform MR image acquisitions of an object while the deionization kit is connected to the cooling system.
Type:
Grant
Filed:
July 11, 2008
Date of Patent:
August 4, 2009
Assignee:
General Electric Company
Inventors:
Julie A. Wong, Garron K. Morris, Akira Imai