With Homogeneity Control Patents (Class 324/320)
  • Patent number: 10408903
    Abstract: The present invention provides a shimming method in which an electric current surface that is virtually placed so as to surround a measurement position is assumed from a magnetic field measurement value, in which an electric current distribution that reproduces a measurement magnetic field is reproduced through an electric current potential, and in which the reproduced magnetic field distribution is used. A magnetic moment or an electric current distribution that reproduces a magnetic field distribution obtained by a magnetic field measurement device is estimated on a predetermined closed surface, and, from the estimated magnetic moment or electric current distribution, a magnetic field distribution of an arbitrary point that exists in the closed surface is estimated. Then, on the basis of the estimated magnetic field distribution, a shim magnetic body distribution that produces a correction magnetic field for correcting the magnetic field distribution at the arbitrary point is output.
    Type: Grant
    Filed: February 19, 2016
    Date of Patent: September 10, 2019
    Assignee: Hitachi, Ltd.
    Inventors: Mitsushi Abe, Kenji Sakakibara, Takuya Fujikawa, Hikaru Hanada
  • Patent number: 10156619
    Abstract: Static magnetic field inhomogeneity is reduced by measuring inhomogeneity of a static magnetic field distribution in an imaging space, evaluating a distribution of a correction magnetic field that should be generated by a correction magnetic field generating unit disposed in the vicinity of the imaging space based on the measured static magnetic field distribution, reducing the electric current value of the superconducting coil to a predetermined (greater than zero) low current value smaller than a rated current value, notifying an operator to set a correction magnetic field of the correction magnetic field generating unit to the correction magnetic field evaluated by calculation in a state where an electric current at the low current value is flowing in the superconducting coil and a low static magnetic field B_low is being generated, and repeating the above operations.
    Type: Grant
    Filed: February 26, 2015
    Date of Patent: December 18, 2018
    Assignee: HITACHI, LTD.
    Inventor: Kenji Sakakibara
  • Patent number: 10006977
    Abstract: Embodiments of the invention are directed to a method for designing the arrangement of superconducting windings for an open MRI system capable of supporting the imaging sequences for CE-BMRI and to a method of coil fabrication that can make a practical magnet from the design.
    Type: Grant
    Filed: August 10, 2015
    Date of Patent: June 26, 2018
    Assignee: The Texas A&M University System
    Inventors: Peter McIntyre, Akhdiyor Sattarov
  • Patent number: 9846209
    Abstract: A homogenization device for homogenization of a magnetic field with an non-magnetic carrier and compensation elements formed of a magnetic material, the carrier having a carrier wall and the carrier wall surrounding a carrier interior, in the homogenization device located in the magnetic field the magnetic field penetrating into the carrier interior through a first carrier region of the carrier wall and emerging from the carrier interior through a second carrier region of the carrier wall and each of the compensation elements which are located on the carrier contributing to the homogenization of the magnetic field at least in the carrier interior. In the homogenization device, handling during homogenization is improved in that there are recesses in the carrier wall and in each of the recesses at least one of the compensation elements can be directly inserted and removed.
    Type: Grant
    Filed: August 19, 2014
    Date of Patent: December 19, 2017
    Assignee: Krohne AG
    Inventors: Ariël de Graaf, Henry van der Linden, Jan Teunis Aart Pors, Jan-Willem Ramondt
  • Patent number: 9841476
    Abstract: To enable improved adjustment of at least one shim channel for magnetic resonance imaging of an examination region of an examination object by operation of a magnetic resonance apparatus that has a shim arrangement with a first shim channel volume having at least one first shim channel and a second shim channel volume having at least one second shim channel, the examination region is divided into multiple of sections, multiple first shim parameter sets are determined for the at least one first shim channel, with one first shim parameter set among the multiple first shim parameter sets being ascertained for each of the multiple sections, a second shim parameter set is ascertained for the at least one second shim channel, taking into account the ascertained multiple first shim parameter sets, and magnetic resonance image data of the examination region are acquired, but before this acquisition, the at least one second shim channel is adjusted using the second shim parameter set and the at least one first shim ch
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: December 12, 2017
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 9835701
    Abstract: Some embodiments of the present disclosure relate to a displacer for reducing the consumption of a cryogen used in a superconductive magnet device. The displacer may occupy some space within the cryogen storage cavity or limit the cryogen into a relatively small space surrounding a superconductive coil in the cryogen storage cavity. The displacer may also include a displacer cavity that may be vacuum or contain a cryogen or another substance.
    Type: Grant
    Filed: March 29, 2017
    Date of Patent: December 5, 2017
    Assignee: SHANGHAI UNITED IMAGING HEALTHCARE CO., LTD.
    Inventors: Jianfeng Liu, Xingen Yu, Lijun Zou, Jin Qian, Yong Jiang, Qing Ni
  • Patent number: 9817093
    Abstract: According to some aspects, a laminate panel is provided. The laminate panel comprises at least one laminate layer including at least one non-conductive layer and at least one conductive layer patterned to form at least a portion of a B0 coil configured to contribute to a B0 field suitable for use in low-field magnetic resonance imaging (MRI).
    Type: Grant
    Filed: September 4, 2015
    Date of Patent: November 14, 2017
    Assignee: Hyperfine Research, Inc.
    Inventors: Jonathan M. Rothberg, Matthew Scot Rosen, Gregory L. Charvat, William J. Mileski, Todd Rearick, Michael Stephen Poole, Keith G. Fife
  • Patent number: 9772386
    Abstract: This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a nuclear magnetic resonance device includes a support frame, a first magnet connected to the support frame, a second magnet connected to the support frame in a manner such that the second magnet is disposed within the magnetic field of the first magnet and a magnetic attraction exists between the first magnet and the second magnet, and a spacer disposed between the first magnet and the second magnet. The spacer is configured to maintain a space between the first magnet and the second magnet.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: September 26, 2017
    Assignee: Fresenius Medical Care Holdings, Inc.
    Inventors: Ross Peter Jones, Simon Grover, Mark David Tuckwell
  • Patent number: 9766312
    Abstract: An NMR apparatus includes a superconducting magnet coil system configured to generate a homogeneous magnetic field, and a helium (He) tank having an inner tube mechanically rigidly connected to the He tank and in which the magnet coil system is positioned. The He tank is configured to contain liquid helium to cool the magnet coils. A radiation shield has a radiation shield inner tube encompassing the He tank and spaced from the He inner tube to create a space between the He inner tube and the radiation shield inner tube to reduce an evaporation rate of the liquid helium. The NMR apparatus additionally includes a field shaping device with a magnetic material arranged in the space, in order to shim the homogeneous magnetic field. The field shaping device is fixed in the space so as to be in rigid mechanical contact with the He tank but without contacting the radiation shield.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: September 19, 2017
    Assignee: Bruker BioSpin AG
    Inventors: Beat Grossniklaus, Guenter Kuebler, Pierre-Alain Bovier
  • Patent number: 9702951
    Abstract: An NMR apparatus includes a superconducting magnet coil system configured to generate a homogeneous magnetic field, and a helium (He) tank having an inner tube mechanically rigidly connected to the He tank and in which the magnet coil system is positioned. The He tank is configured to contain liquid helium to cool the magnet coils. A radiation shield has a radiation shield inner tube encompassing the He tank and spaced from the He inner tube to create a space between the He inner tube and the radiation shield inner tube to reduce an evaporation rate of the liquid helium. The NMR apparatus additionally includes a field shaping device with a magnetic material arranged in the space, in order to shim the homogeneous magnetic field. The field shaping device is fixed in the space so as to be in rigid mechanical contact with the He tank but without contacting the radiation shield.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: July 11, 2017
    Assignee: Bruker BioSpin AG
    Inventors: Beat Grossniklaus, Guenter Kuebler, Pierre-Alain Bovier
  • Patent number: 9678181
    Abstract: A method for shimming a magnetic field in a magnetic resonance tomography (MRT) device includes determining a field of view region for an object under examination. Determining the field of view region includes adapting the field of view region automatically to a region of the object under examination to be examined by the MRT device. Before the MRT device records an image, an adjustment measurement of the magnetic field is performed. A field map of the magnetic field of the field of view region is defined based on the adjustment measurement. A shimming of the magnetic field is implemented based on the field map.
    Type: Grant
    Filed: May 17, 2013
    Date of Patent: June 13, 2017
    Assignee: Siemens Aktiengesellschaft
    Inventors: Dominik Paul, Benjamin Schmitt
  • Patent number: 9675271
    Abstract: Systems and methods for delivery of radiotherapy in conjunction with magnetic resonance imaging in which various conductors, shields and shims may be used to solve issues occurring when radiation therapy equipment is placed in the vicinity of an magnetic resonance imaging system.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: June 13, 2017
    Assignee: ViewRay Technologies, Inc.
    Inventors: Shmaryu M. Shvartsman, James F. Dempsey, David Nicolay
  • Patent number: 9671479
    Abstract: In a method and apparatus for shimming a superconducting magnet that has a number of magnet coils electrically connected in series between a first current connection and a second current connection and a superconducting switch connected in parallel with the magnet coils, between the first current connection and the second current connection, with the first current connection being electrically connected to an external current lead, a first solid-state switching device is electrically interposed between the external current lead and the magnet coils; a number of superconducting shim coils electrically connected between the first current connection and the second current connection through a further solid-state switching device. Superconducting switches are each connected in parallel with a respective superconducting shim coil.
    Type: Grant
    Filed: August 9, 2013
    Date of Patent: June 6, 2017
    Assignee: Siemens PLC
    Inventor: Hugh Alexander Blakes
  • Patent number: 9651353
    Abstract: One or more embodiments are directed to a magnet configured to be coupled to an object under test, an array of sensors configured to measure a magnetic field associated with the magnet, and a circuit configured to obtain voltage readings based on the measured magnetic field from the array of sensors and compute a distance between the array of sensors and the magnet based on the obtained voltage readings.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: May 16, 2017
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Oki Gunawan
  • Patent number: 9632153
    Abstract: A magnetic resonance imaging configuration, system and method to straighten and otherwise homogenize the field lines in the imaging portion, creating improved image quality. Through use of calibrated corrective coils, magnetic field lines can be manipulated to improve uniformity and image quality. Additionally, when the apparatus is composed of non-ferromagnetic materials, field strengths can be increased to overcome limitations of Iron-based systems such as by use of superconductivity. A patient positioning apparatus allows multi-positioning of a patient within the calibrated and more uniform magnetic field lines.
    Type: Grant
    Filed: January 25, 2016
    Date of Patent: April 25, 2017
    Assignee: Fonar Corporation
    Inventors: Raymond V. Damadian, Gordon T. Danby, Hank Hsieh, John W. Jackson, Mark Gelbien, William H. Wahl, Charles A. Green
  • Patent number: 9541616
    Abstract: According to some aspects, a laminate panel is provided. The laminate panel comprises at least one laminate layer including at least one non-conductive layer and at least one conductive layer patterned to form at least a portion of a B0 coil configured to contribute to a B0 field suitable for use in low-field magnetic resonance imaging (MRI).
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: January 10, 2017
    Assignee: Hyperfine Research, Inc.
    Inventors: Jonathan M. Rothberg, Matthew Scot Rosen, Gregory L. Charvat, William J. Mileski, Todd Rearick, Michael Stephen Poole
  • Patent number: 9513353
    Abstract: A method of determining a magnet arrangement for use in magnetic resonance imaging apparatus, the method including, determining a function representing current densities required within a magnet region to generate a field, determining a current density distribution required to generate a desired field, using the function and determining the magnet arrangement using the current density distribution, the magnet arrangement including a number of current carrying coils arranged within the magnet region.
    Type: Grant
    Filed: May 7, 2009
    Date of Patent: December 6, 2016
    Assignee: THE UNIVERSITY OF QUEENSLAND
    Inventors: Quang Minh Tieng, Viktor Vegh, Ian Malcolm Brereton
  • Patent number: 9506995
    Abstract: The present invention provides a magnetic field analysis program and a magnetic field analysis method for calculating inductance related to an AC magnetic field superimposed on a DC magnetic field with a high degree of accuracy at high speed.
    Type: Grant
    Filed: June 5, 2012
    Date of Patent: November 29, 2016
    Assignee: Hitachi, Ltd.
    Inventor: Kohji Maki
  • Patent number: 9329247
    Abstract: A shim coil arrangement for at least one extremity of a patient such as a forearm and/or a hand for use in a magnetic resonance device is provided. The shim coil arrangement is arranged surrounding a receptacle for the at least one extremity. At least two planar shim coils having a common coil plane that lies at right angles to a direction of a basic magnetic field of the magnetic resonance device in a usage state and/or to a longitudinal direction of the receptacle are arranged around a circumference of the receptacle. A plurality of coil planes succeeding one another in the direction of the basic magnetic field of the magnetic resonance device in the usage state and/or the longitudinal direction of the receptacle and at right angles to the direction of the basic magnetic field and/or the longitudinal direction are provided with at least two planar shim coils.
    Type: Grant
    Filed: April 16, 2013
    Date of Patent: May 3, 2016
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stephan Biber
  • Patent number: 9329249
    Abstract: A shim coil for use in magnetic resonance imaging spectroscopy (MRIS) is formed by cutting or punching in a sheet of electrically conductive material the required coil pattern. The pattern can be punched using a CNC punching or stamping machine.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: May 3, 2016
    Assignee: Tesla Engineering Limited
    Inventor: Michael Colin Begg
  • Patent number: 9325183
    Abstract: An apparatus including a magnet assembly having at least two magnet assembly components; and an eddy current heating reduction system configured to reduce heating of the magnet assembly by magnetic fields. The eddy current heating reduction system includes electrical insulation between the at least two magnet assembly components, and includes at least one of the at least two magnet assembly components having a divided current loop area at least two spaced subsections.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: April 26, 2016
    Assignee: Nokia Technologies Oy
    Inventor: Juha Reinhold Backman
  • Patent number: 9276325
    Abstract: An electromagnetic wave reverberation chamber formed in the shape of a polyhedron includes an electromagnetic wave absorbing apparatus installed on at least one wall of metal conductors of the electromagnetic wave reverberation chamber. The electromagnetic wave absorbing apparatus having a shape of a roll screen and includes an electromagnetic wave absorbing film, a roll for rolling the one end of the electromagnetic wave absorbing film, a cover for covering the roll, and a fixing unit for fixing the other end of the electromagnetic wave absorbing film.
    Type: Grant
    Filed: August 21, 2012
    Date of Patent: March 1, 2016
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventor: Dong-Uk Sim
  • Patent number: 9234949
    Abstract: Disclosed is a compact superconducting magnet device for generating an intense and homogeneous magnetic field component Bz along an axis Oz in a zone of interest ZI successively includes, starting from the axis Oz, at least two coaxial superconducting helical coils formed around circular cylinder sections of axis Oz delimited by end circles. The lateral ends of the helical coils are arranged, to within the thickness of the coils, in the vicinity of one same sphere of radius c whose center O is placed on the axis Oz at the center of the zone of interest ZI and which encompasses the magnetic device assembly. The azimuthal current densities j1, j2 of the helical coils are of opposite sign. The lengths of the helical coils are of decreasing length.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: January 12, 2016
    Assignee: Commissariat A L'Energie Atomique Et Aux Energies Alternatives
    Inventor: Guy Aubert
  • Patent number: 9213073
    Abstract: An MRI system has a cylindrical superconducting magnet assembly contained in a bore tube of a cylindrical vacuum vessel (OVC), and a gradient coil assembly situated within the OVC bore tube. In an imaging region within a bore of the gradient coil assembly, the magnet assembly produces a magnetic field that is subject to drift during operation of the MRI system. Compensating material is located at a radial position between the imaging region and the magnet in a location that will be heated over a range of temperatures during operation of the MRI system. The compensating material is adjustable between two magnetic phases in response to an applied physical characteristic, which is selectively applied thereto so as to change the compensating material from a first magnetization to a second magnetization, and thereby compensate the drift.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: December 15, 2015
    Assignee: Siemens PLC
    Inventor: Nicholas Paul Aley
  • Patent number: 9075102
    Abstract: A MRI system for acquiring MRI image data comprising a data acquisition means comprising a plurality of subunits for acquiring MRI image data, a power distribution means for providing the means for acquiring MRI image data with electrical power, the power distribution means comprising: a power supply unit adapted for providing direct current electrical power from an alternating current electrical mains, a power bus adapted for supplying the subunits with the direct current electrical power, control means for controlling the supply of direct current electrical power by the power bus to the subunits.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: July 7, 2015
    Assignee: KONINKLIJKE PHILIPS N.V.
    Inventor: Cornelis Leonardus Gerardus Ham
  • Patent number: 8984684
    Abstract: The magnetic resonance imaging device of the present invention includes a gantry and a bed part comprising a top panel, the gantry comprises a circumferential panel covering outer circumference of a tunnel-shaped static magnetic field space, and a front panel having an opening serving as entrance of a bore for the static magnetic field space, this front panel comprises an arc-shaped outer panel extending from an upper part of the opening serving as entrance of the bore to the ground plane via both sides of the opening, and an inner panel disposed inside the outer panel, a portion connecting the outer panel and the inner panel constitutes a top surface protruding forwardly, and the inner panel is formed in a recessed shape with a concave curved surface extending from the top surface to the opening serving as entrance of the bore.
    Type: Grant
    Filed: July 14, 2011
    Date of Patent: March 24, 2015
    Assignee: Hitachi Medical Corporation
    Inventors: Atsushi Ninomiya, Masaru Yokoyama, Kazuyuki Yanase, Manabu Yanagimoto, Takeshi Yatsuo, Hiroyuki Ohzeki
  • Patent number: 8981779
    Abstract: Active resistive shim coil assemblies may be used in magnetic resonance imaging (MRI) systems to reduce in-homogeneity of the magnetic field in the imaging volume. Disclosed embodiments may be used with continuous systems, gapped cylindrical systems, or vertically gapped systems. Disclosed embodiments may also be used with an open MRI system and can be used with an instrument placed in the gap of the MRI system. An exemplary embodiment of the active resistive shim coil assembly of the present disclosure includes active resistive shim coils each operable to be energized by separate currents through a plurality of power channels. In some embodiments, the disclosed active resistive shim coil assemblies allow for various degrees of freedom to shim out field in-homogeneity.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: March 17, 2015
    Assignee: ViewRay Incorporated
    Inventors: Shmaryu Shvartsman, James Dempsey, Gordon DeMeester
  • Publication number: 20150070018
    Abstract: A homogenization device for homogenization of a magnetic field with an non-magnetic carrier and compensation elements formed of a magnetic material, the carrier having a carrier wall and the carrier wall surrounding a carrier interior, in the homogenization device located in the magnetic field the magnetic field penetrating into the carrier interior through a first carrier region of the carrier wall and emerging from the carrier interior through a second carrier region of the carrier wall and each of the compensation elements which are located on the carrier contributing to the homogenization of the magnetic field at least in the carrier interior. In the homogenization device, handling during homogenization is improved in that there are recesses in the carrier wall and in each of the recesses at least one of the compensation elements can be directly inserted and removed.
    Type: Application
    Filed: August 19, 2014
    Publication date: March 12, 2015
    Applicant: Krohne AG
    Inventors: Ariël de Graaf, Henry van der Linden, Jan Teunis Aart Pors, Jan-Willem Ramondt
  • Patent number: 8965468
    Abstract: A persistent-mode High Temperature Superconductor (HTS) shim coil is provided having at least one rectangular shaped thin sheet of HTS, wherein the thin sheet of HTS contains a first long portion, a second long portion parallel to first long portion, a first end, and a second end parallel to the first end. The rectangular shaped thin sheet of high-temperature superconductor has a hollow center and forms a continuous loop. In addition, the first end and the second end are folded toward each other forming two rings, and the thin sheet of high-temperature superconductor has a radial build that is less than 5 millimeters (mm) and able to withstand very strong magnetic field ranges of greater than approximately 12 Tesla (T) within a center-portion of a superconducting magnet of a superconducting magnet assembly.
    Type: Grant
    Filed: October 25, 2012
    Date of Patent: February 24, 2015
    Assignee: Massachusetts Institute of Technology
    Inventor: Yukikazu Iwasa
  • Patent number: 8947089
    Abstract: A measured error magnetic field distribution is divided into eigen-mode components obtained by a singular decomposition and iron piece arrangements corresponding to respective modes are combined and arranged on a shim-tray. An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being known, an erroneous adjustment can also be known, and the adjustment is automatically done during repeated adjustments. As a result, an apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of being able to detect a poor magnet earlier by checking the attainable homogeneity.
    Type: Grant
    Filed: May 8, 2009
    Date of Patent: February 3, 2015
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Mitsushi Abe, Ryuya Ando, Takeshi Nakayama
  • Patent number: 8902030
    Abstract: Device for generating an orientable and locally uniform magnetic field, including N?3 identical assemblies of cylindrical coils, each assemblies having a first and a second coil, the coils being coaxial with an axis oriented along a direction z and arranged symmetrically on either side of the plane, with a gap in the axial direction, the assemblies arranged such that their outlines in a plane xy perpendicular to the z-axis are regularly spaced along a circle of center O and of radius a0>0, so to leave a central free space. A supply system supplies the coils with a current set to obtain, at the center of the device, a magnetic field having the desired orientation. The device may include two pairs of cylindrical coils having a common axis oriented in said z-direction and passing through the center of the circle, these coils being arranged symmetrically on either side of said xy-plane.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: December 2, 2014
    Assignee: Commissariat a l'energie Atomique et aux Energies Alternatives
    Inventor: Guy Aubert
  • Patent number: 8896310
    Abstract: Methods of fastening a cage with a fastening system in an MRD. One method includes: assembling: a plurality of pole pieces; a plurality of side magnets, the side magnets substantially enclosing the pole pieces and thereby defining a magnetic envelope and enclosed volume therein; a plurality of side walls, the side walls substantially enclosing the side magnets; a plurality of face walls and a plurality of fastening rods; and passing a plurality of fastening rods through at least one of the side magnets and at least one of the pole pieces and fastening them in an effective measure, such that the rods physically interconnects at least one pair of side walls.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: November 25, 2014
    Assignee: Aspect Imaging Ltd.
    Inventor: Uri Rapoport
  • Patent number: 8890530
    Abstract: According to one embodiment, an MRI apparatus includes a signal acquisition unit, an image generating unit, a position acquiring unit, and a correction unit. The signal acquisition unit acquires a magnetic resonance signal produced from an object by applying a gradient magnetic field and an RF pulse in an imaging space where the object is placed. The image generating unit reconstructs image data on the object based on the magnetic resonance signal. The position acquiring unit acquires an imaging region as positional information in the imaging space. The correction unit brings a distribution of the gradient magnetic field close to a target distribution by transforming a waveform of the gradient magnetic field based on the positional information and a time constant of an eddy-current magnetic field to cancel the eddy-current magnetic field.
    Type: Grant
    Filed: July 21, 2011
    Date of Patent: November 18, 2014
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
    Inventors: Masaaki Umeda, Mitsukazu Kamata
  • Patent number: 8885329
    Abstract: When testing or powering up a magnet in a magnetic resonance imaging device, a switch is provided that switches a winding between resistive and superconductive modes. The switch includes a housing that contains a winding wound about a bobbin, and an internal coolant cavity that contains coolant that cools the winding, A baffle separates the internal coolant cavity from an external coolant reservoir. The baffle has small apertures that permit influx of liquid coolant into the internal cavity to cool the winding, At high temperatures, the coolant in the internal cavity vaporizes causing the winding to further increase its temperature and resistance, Upon reduction of heat to the winding, the winding cools sufficiently to permit influx of liquid coolant, thereby restoring a superconductive mode of operation to the winding.
    Type: Grant
    Filed: November 23, 2009
    Date of Patent: November 11, 2014
    Assignee: Koninklijke Philips N.V.
    Inventor: Alexander A. Akhmetov
  • Publication number: 20140274721
    Abstract: A cylindrical superconducting magnet system for use in magnetic resonance imaging has axially aligned primary superconducting coils that are situated within an outer vacuum chamber (OVC). A thermal radiation shield surrounds the primary superconducting coils within the OVC. A primary gradient coil assembly is axially aligned with the primary superconducting coils and is situated radially within the primary superconducting coils. The cylindrical superconducting magnetic system also includes a secondary gradient coil assembly, that is radially situated outside of the primary superconducting coils and that is mechanically attached to the primary gradient coil assembly.
    Type: Application
    Filed: November 19, 2012
    Publication date: September 18, 2014
    Inventor: Simon James Calvert
  • Patent number: 8836332
    Abstract: A radiation therapy system comprises a magnetic resonance imaging (MRI) system combined with an irradiation system, which can include one or more linear accelerators (linacs) that can emit respective radiation beams suitable for radiation therapy. The MRI system includes a split magnet system, comprising first and second main magnets separated by gap. A gantry is positioned in the gap between the main MRI magnets and supports the linac(s) of the irradiation system. The gantry is rotatable independently of the MRI system and can angularly reposition the linac(s). Shielding can also be provided in the form of magnetic and/or RF shielding. Magnetic shielding can be provided for shielding the linac(s) from the magnetic field generated by the MRI magnets. RF shielding can be provided for shielding the MRI system from RF radiation from the linac.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: September 16, 2014
    Assignee: ViewRay Incorporated
    Inventors: Shmaryu M. Shvartsman, Gordon DeMeester, James F. Dempsey, John Lester Patrick
  • Patent number: 8816688
    Abstract: A magnetic resonance imaging apparatus includes an imaging condition acquisition unit and an imaging unit. The imaging condition acquisition unit acquires at least one of optimum amplitude and optimum phase of a radio frequency transmission signal so as to reduce a deviation of data in at least one region of interest set in an object. The imaging unit acquires image data by imaging according to an imaging condition including at least one of optimum amplitude and optimum phase.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: August 26, 2014
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
    Inventors: Kohei Adachi, Masatoshi Hanawa, Kazuya Okamoto
  • Patent number: 8816684
    Abstract: Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.
    Type: Grant
    Filed: October 28, 2010
    Date of Patent: August 26, 2014
    Assignee: Vista Clara Inc.
    Inventor: David O. Walsh
  • Publication number: 20140225610
    Abstract: In order to detect a magnetic resonance (MR) signal in an examination region of an examination subject in a measurement field of an MR system with an MR imaging sequence, a magnetization in the examination subject is generated with a polarization field B0. The MR system has a magnet to generate the polarization field B0 with a first field inhomogeneity across the measurement field. At least one RF pulse is radiated into the examination region. At least one first magnetic field gradient is activated for spatial coding of the MR signal. At least one pulsed compensation magnetic field gradient is activated that is generated by a temporally variable current that varies over the duration of the MR imaging sequence and that is activated over a compensation time period that is shorter than the total duration of the imaging sequence so that, during the compensation time period, the first field inhomogeneity is reduced to a second, lower field inhomogeneity across the measurement field.
    Type: Application
    Filed: February 12, 2014
    Publication date: August 14, 2014
    Inventor: Stefan Popescu
  • Patent number: 8797034
    Abstract: A magnetic resonance imaging configuration to straighten and otherwise homogenize the field lines in the imaging portion, creating improved image quality. Through use of calibrated corrective coils, magnetic field lines can be manipulated to improve uniformity and image quality. Additionally, when the apparatus is composed of non-ferromagnetic materials, field strengths can be increased to overcome limitations of Iron-based systems such as by use of superconductivity. A patient positioning apparatus allows multi-positioning of a patient within the calibrated and more uniform magnetic field lines.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: August 5, 2014
    Assignee: FONAR Corporation
    Inventors: Raymond V. Damadian, Gordon T. Danby, Hank Hsieh, John W. Jackson, Mark Gelbien, William H. Wahl, Charles A. Green
  • Patent number: 8755863
    Abstract: A magnetic resonance imaging apparatus includes a magnet having two poles and a wall connecting the poles; the poles delimiting a patient-imaging space; and a table which is slidably connected to one of the two poles between the two poles and which table extends substantially parallel to the two poles; a drive for displacing the table relative to the magnet; a lock for locking the table in a selected position relative to the magnet; a drive for rotating the magnet about the axis; the table connected to the magnet such that the table rotates with the magnet when the magnet rotates about the axis; the magnet and the table being rotatable from a position in which the poles and the table are horizontal to a position in which the table and the poles are vertical.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: June 17, 2014
    Assignee: Esaote S.p.A.
    Inventors: Luigi Satragno, Eugenio Biglieri, Fabio Rezzonico, Osvaldo Pugliese, Orfeo Contrada, Alessandro Trequattrini
  • Patent number: 8729899
    Abstract: A magnetic resonance imaging (MRI) system magnet includes at least one main electromagnet winding disposed within a first radius of the magnet and at least one bucking electromagnet winding disposed within a second radius, larger than the first radius of the magnet and configured to provide self-shielding magnetic fields that substantially reduce fringe magnetic fields outside the magnet produced by the main electromagnet winding. The combination of magnetic fields produced by both the main and bucking electromagnet windings inside the magnet conform to MRI requirements within at least an imaging volume. The main and bucking electro-magnet windings are configured so as to create a net fringe field outside the magnet within the range of 50-100 gauss at a distance within a range of 3-5 meters axially and 2-3 meters radially from a center of the magnet.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: May 20, 2014
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
    Inventors: Michael Steckner, Bruce C. Breneman
  • Patent number: 8729898
    Abstract: A capillary cartridge assembly for positioning a sample fluid at a geometric center between juxtaposed pole pieces of a NMR magnet assembly for NMR analysis comprises a capillary captured in a channel in a printed circuit board assembly that is sized to fit between the pole pieces. The assembly includes a RF coil surrounding a portion of the capillary. Electric traces shaped to function as shim coils can be included in the printed circuit board. An end of the printed circuit board includes electrically conductive contacts that plug into a receptacle to connect the RF coil and traces to external electrical circuitry when the RF coil is in the geometric center. The capillary can be a continuous flow-through capillary or a closed cartridge.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: May 20, 2014
    Assignee: Picospin, LLC
    Inventors: John C. Price, Chris Jonkman
  • Patent number: 8723523
    Abstract: A magnetic resonance imaging apparatus includes: a pair of static magnetic field generators separately disposed at the top and bottom of an imaging space in which a subject is placed; a shim magnetic material, disposed on the imaging-space side of each of the pair of static magnetic field generators, for generating a magnetic field to adjust the static magnetic field; a gradient magnetic field generator; a high-frequency magnetic field generator; a temperature sensor for directly or indirectly measuring the temperature of the shim magnetic material; and a controller for controlling the gradient magnetic field generator and the high-frequency magnetic field generator to execute an imaging pulse sequence.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: May 13, 2014
    Assignee: Hitachi Medical Corporation
    Inventor: Munetaka Tsuda
  • Patent number: 8698499
    Abstract: An electromagnet device which generates magnetic field in the direction perpendicular to the inserting direction of an inspection subject is reduced in size and weight by removing unnecessary arrangement as much as possible. A magnetic resonance imaging device is also provided. The electromagnet device comprises a first coil (31) through which a first circular current (J1) circulates forward, a second coil (32) through which a second circular current (J2) circulates reversely, and a coil group (30) through which a plurality of circular currents (J3-J6) circulate alternately forward and reversely. The first coil (30), the second coil (32) and the coil group (30) are arranged in this order to increase the angle of elevation ? (?1<?2<?3), and a blank region (S) not including the second coil (32) and the coil group (30) exists in the angular region between the angles of elevation ?2 and ?3.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: April 15, 2014
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Mitsushi Abe, Hiroyuki Watanabe, Hirotaka Takeshima
  • Publication number: 20140091792
    Abstract: A method for producing a hyperpolarized sample for use in a magnetic resonance investigation has the following steps: a) providing a solid sample (50), containing long T1 nuclei and short T1 nuclei in the same molecules (51); b) hyperpolarizing the short T1 nuclei in the solid sample (50); c) transforming the solid sample (50) into a liquid sample (52); and d) transferring the polarization of the short T1 nuclei to the long T1 nuclei within the molecules in the liquid sample (52) by Cross Polarization. The method can provide samples with hyperpolarized long T1 nuclei, in particular 13C or 15N, in a simple and efficient way.
    Type: Application
    Filed: October 3, 2012
    Publication date: April 3, 2014
    Applicants: ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL), BRUKER BIOSPIN AG
    Inventors: Sami Jannin, Joost Lohman, Geoffrey Bodenhausen, Klaes Golman
  • Publication number: 20140043028
    Abstract: In a method and apparatus for shimming a superconducting magnet that has a number of magnet coils electrically connected in series between a first current connection and a second current connection and a superconducting switch connected in parallel with the magnet coils, between the first current connection and the second current connection, with the first current connection being electrically connected to an external current lead, a first solid-state switching device is electrically interposed between the external current lead and the magnet coils; a number of superconducting shim coils electrically connected between the first current connection and the second current connection through a further solid-state switching device. Superconducting switches are each connected in parallel with a respective superconducting shim coil.
    Type: Application
    Filed: August 9, 2013
    Publication date: February 13, 2014
    Inventor: Hugh Alexander Blakes
  • Patent number: 8643368
    Abstract: The Rabi frequency of oscillation of the nuclear magnetization vector of a sample in an NMR system may be controlled by modifying only the duty cycle of RF pulses delivered to the sample, without modifying the amplitude of the RF pulses, until the energy delivered at the Larmor frequency is adjusted to a desired amount. An impedance matching network between an NMR transceiver and an NMR coil may perform both power matching and noise matching simultaneously. During a transmission mode, the impedance matching network is connected to a transmitter portion of the transceiver, and the impedance of the coil is matched to the driver resistance. During a receiver mode, the impedance matching network is disconnected from the transmitter portion so that the impedance matching network remains connected only to the receiver portion, and signal-to-noise ratio in received NMR signals is maximized.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: February 4, 2014
    Assignee: President and Fellows of Harvard College
    Inventors: Nan Sun, Donhee Ham
  • Patent number: 8638101
    Abstract: In a method and device for compensating the insufficient homogeneity of a magnetic field in a magnetic resonance system, the spatial position and size of a basic magnetic field region and at least one additional magnetic field region in a field to be homogenized and determined. An optimization calculation is implemented on the basic magnetic field region and the at least one additional magnetic field region. A homogenized magnetic field at the main magnetic field region and the at least one additional magnetic field region is output according to the result of the optimization calculation.
    Type: Grant
    Filed: August 24, 2010
    Date of Patent: January 28, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jin Jun Chen, Cheng Ni
  • Patent number: RE47026
    Abstract: A magnetic resonance system is disclosed. The system includes a transceiver having a multichannel receiver and a multichannel transmitter, where each channel of the transmitter is configured for independent selection of frequency, phase, time, space, and magnitude, and each channel of the receiver is configured for independent selection of space, time, frequency, phase and gain. The system also includes a magnetic resonance coil having a plurality of current elements, with each element coupled in one to one relation with a channel of the receiver and a channel of the transmitter. The system further includes a processor coupled to the transceiver, such that the processor is configured to execute instructions to control a current in each element and to perform a non-linear algorithm to shim the coil.
    Type: Grant
    Filed: September 20, 2012
    Date of Patent: September 4, 2018
    Assignee: Regents of the University of Minnesota
    Inventors: J Thomas Vaughan, Pierre-Francois Van de Moortele, Lance DelaBarre, Chris E Olson, Heather Orser, Anand Gopinath, Kamil Ugurbil, Carl Snyder, Gregor Adriany, Can Akgun, Jinfeng Tian, John Strupp, Peter M Andersen