Including Polarizing Magnetic Field/radio Frequency Tuning Patents (Class 324/313)
  • Patent number: 11169230
    Abstract: Various approaches of amplifying an NMR signal in response to a transmitted NMR pulse include estimating the characteristic time associated with the NMR signal; transmitting the NMR pulse to the sample and receiving the NMR signal therefrom; and applying a time-dependent amplifier gain to the received NMR signal based at least in part on the estimated characteristic time.
    Type: Grant
    Filed: April 16, 2020
    Date of Patent: November 9, 2021
    Assignee: WAVEGUIDE CORPORATION
    Inventor: Sebastian Patulea
  • Patent number: 11137464
    Abstract: In a method and magnetic resonance (MR) apparatus for acquiring MR data from a volume of an object in which first and second excitable spin types are present that differ in their Larmor frequencies by a chemical shift, an MR sequence with at least one radio-frequency pulse sequence selectively excites the first spin type or selectively suppresses MR signals of the second spin type. A B0 map describing the basic field distribution in a region of interest of the volume is established. First and second items of distribution information, which respectively describe the spectral distribution of Larmor frequencies of the first and second spin types, are derived from the B0 map. A pulse sequence parameter that describes the excitation spectrum of the radio-frequency pulse sequence is optimized based on the items of distribution information, with regard to a quality criterion that optimizes selective excitation and/or suppression.
    Type: Grant
    Filed: January 24, 2018
    Date of Patent: October 5, 2021
    Assignee: Siemens Healthcare GmbH
    Inventors: Michael Koehler, Thorsten Feiweier
  • Patent number: 11131730
    Abstract: A magnetic resonance coil having at least one tuning device for tuning the magnetic resonance coil, a magnetic resonance device, and a method for tuning a magnetic resonance coil are provided. The at least one tuning device includes a plurality of capacitors that are mechanically interlinked.
    Type: Grant
    Filed: September 13, 2018
    Date of Patent: September 28, 2021
    Assignee: Siemens Healthcare GmbH
    Inventors: Ludwig Eberler, Razvan Lazar, Volker Matschl, Jürgen Nistler, Martin Schramm
  • Patent number: 10955500
    Abstract: A low-field magnetic resonance imaging (MRI) system. The system includes a plurality of magnetics components comprising at least one first magnetics component configured to produce a low-field main magnetic field B0 and at least one second magnetics component configured to acquire magnetic resonance data when operated, and at least one controller configured to operate one or more of the plurality of magnetics components in accordance with at least one low-field zero echo time (LF-ZTE) pulse sequence.
    Type: Grant
    Filed: March 2, 2020
    Date of Patent: March 23, 2021
    Assignee: Hyperfine Research, Inc.
    Inventors: Laura Sacolick, Matthew Scot Rosen, Gregory L. Charvat, Jonathan M. Rothberg, Mathieu Sarracanie
  • Patent number: 10638950
    Abstract: In order to provide a static magnetic field homogeneity adjustment method capable of reducing an arrangement amount of magnetic pieces and achieving desired magnetic field homogeneity with high accuracy in magnetic field homogeneity adjustment, there is provided a static magnetic field homogeneity adjustment method in an imaging space of computing positions of a plurality of magnetic pieces separated from the imaging space through shimming computation with respect to a static magnetic field in the imaging space generated by a magnetic field generation device, and disposing the plurality of magnetic pieces at the positions obtained through the shimming computation, the method including an adjustment step of imposing restriction that a polarity of a magnetic field distribution generated in the imaging space by the magnetic pieces disposed at the positions is either positive or negative during the shimming computation, and adjusting the static magnetic field homogeneity.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: May 5, 2020
    Assignee: HITACHI, LTD.
    Inventors: Takuya Fujikawa, Mitsushi Abe, Kenji Sakakibara, Hikaru Hanada
  • Patent number: 10627463
    Abstract: Apparatus and method that are more efficient and flexible, and obtain and connect high-power RF transmit signals (TX) to RF-coil devices in an MR machine or other devices and simultaneously receive signals (RX) and separate net receive signals NRX) of interest by subtracting or filtering to remove the subtractable portion of the transmit signal (STX) from the RX and preamplifying the NRX and signal processing the preamplified NRX. In some embodiments, signal processing further removes artifacts of the transmitted signal, e.g., by digitizing the NRX signal, storing the digitized NRX signal in a memory, and performing digital signal processing. In some embodiments, the present invention also includes pre-distorting the TX signals in order to be better able to identify and/or remove the remaining artifacts of the transmitted signal from the NRX signal. This solution also applies to other high-power RF-transmit-antennae signals.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: April 21, 2020
    Assignee: Life Services, LLC
    Inventors: Scott M. Schillak, John Thomas Vaughan, Charles A. Lemaire, Matthew T. Waks
  • Patent number: 10564235
    Abstract: An imaging unit producing images, and a control unit controlling the imaging unit. The imaging device further comprises: a reference clock unit generating a reference clock; and a signal input/output unit provided between the imaging unit and the control unit and inputting and outputting signals in synchronization with the reference clock generated by the reference clock unit. The control unit comprises: generating unit generating a plurality of control signals; transmitting unit transmitting the plural control signals; receiving unit receiving measurement signals; and extraction unit extracting the measurement signal when the reception times of the measurement signals received by the receiving unit agrees with the extraction timing generated by the generating unit.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: February 18, 2020
    Assignee: MRTechnology, Inc.
    Inventors: Tomoyuki Haishi, Seitaro Hashimoto, Katsumi Kose
  • Patent number: 10488486
    Abstract: Various embodiments include apparatus and methods to calibrate a nuclear magnetic resonance tool. Example calibration techniques may include using intended ninety degree pulses as a control mechanism to evaluate echo pulses from generating pulse sequences. Example calibration techniques may include comparing a sequence of measurement signals with a reference sequence. Additional apparatus, systems, and methods are disclosed.
    Type: Grant
    Filed: May 30, 2013
    Date of Patent: November 26, 2019
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Rebecca Corina Jachmann, Jie Yang
  • Patent number: 10338174
    Abstract: A method for creating a first MRI image and a second MRI image is provided. A first echo is read out. A second echo is read out. The first echo readout is used to generate a first image set, with each image pixel being a first linear combination of the first species and the second species. The second echo readout is used to generate a second image set, with each image pixel being a second linear combination of the first species and the second species. The first image set and second image set are combined to obtain a first combined image containing only the first species and a second combined image containing only the second species, comprising combining the first image set and the second image set to generate two pairs of solutions and using a mathematical optimization to choose a correct pair of solutions.
    Type: Grant
    Filed: November 15, 2016
    Date of Patent: July 2, 2019
    Assignee: The Board of Trustees of the Leland Stanford Junior Univesity
    Inventors: Tao Zhang, Yuxin Chen, John M. Pauly, Shreyas S. Vasanawala
  • Patent number: 10042021
    Abstract: A magnetic field measuring method in a magnetic resonance imaging (MRI) apparatus includes applying a radio frequency (RF) pulse to an object, acquiring first and second echo signals from a first readout gradient according to test gradients having different intensities, acquiring third and fourth echo signals from a second readout gradient according to the test gradients having different intensities, and determining a characteristic value of an eddy field based on an echo time (TE) of at least one of the first through the fourth echo signals.
    Type: Grant
    Filed: July 8, 2014
    Date of Patent: August 7, 2018
    Assignee: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Dae-ho Lee, Sang-young Zho, Joon-soo Kim
  • Patent number: 9857315
    Abstract: A spectrometer includes: (1) a housing defining a volume into which an analyte gas is introduced, the analyte gas including a chiral component; (2) a microwave generator coupled to the housing and configured to apply a microwave pulse to the analyte gas, the microwave pulse being polarized along a first direction; (3) an electric field generator coupled to the housing and configured to apply a switched electric field to the analyte gas, the electric field being oriented along a second direction different from the first direction; (4) a phase-sensitive microwave detector coupled to the housing and configured to detect an induced microwave emitted by the analyte gas, the induced microwave being polarized along a third direction different from the first direction and the second direction; and (5) an analyzer coupled to the phase-sensitive microwave detector and configured to detect an enantiomer of the chiral component based on a phase of the induced microwave.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: January 2, 2018
    Assignee: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: David S. Patterson, John M. Doyle
  • Patent number: 9724534
    Abstract: A system for providing a magnetic resonance treatment may include components that provide the system with an ability to treat pain and relieve symptoms of the subject. In another embodiment, a method of providing a magnetic resonance treatment includes components that provide the system with an ability to treat pain, relieve symptoms, provide relaxation, and improve the overall comfort and well-being of the subject.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: August 8, 2017
    Assignee: Applied Magnetics, LLC
    Inventors: Jerry I. Jacobson, Allen Braswell, Jr.
  • Patent number: 9557398
    Abstract: A method is proposed for the simultaneous optimization of an arbitrary number of electromagnetic pulses, which act in a cooperative way, or mutually compensate each other's errors. The method generally relates to pulses which can have improved properties when cooperating with each other compared to single pulses. In experiments with several scans, undesired signal contributions can be suppressed by COOP pulses, which complements and generalizes the concept of phase cycling. COOP pulses can also be used in individual scans. COOP pulses can be optimized efficiently with the aid of an extended version of the optimal-control-theory-based gradient ascent pulse engineering (GRAPE) algorithm. The advantage of the COOP pulse method is demonstrated theoretically and experimentally for broadband and band-selective excitation and saturation pulses.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: January 31, 2017
    Assignee: Technische Universitaet Muenchen
    Inventors: Steffen J. Glaser, Michael Braun
  • Patent number: 9406422
    Abstract: There is provided a superconducting magnet in which magnetization caused by a shielding current of a superconducting winding is eliminated whereby the current to be supplied to the superconducting winding is uniformized, and thus uniformity of the central magnetic field is secured. The superconducting magnet has a superconducting winding composed of a superconductor, and an outer AC winding composed of a superconductor or non-superconductor wound coaxially with the superconducting winding, at an outer side the superconducting winding; and an AC current is supplied to the outer AC winding thereby applying an AC magnetic field in a direction perpendicular to a direction of magnetization caused in the superconducting winding by the shielding current, and thus the magnetization is eliminated. Also, the superconducting magnet has an inner AC winding composed of a superconductor or non-superconductor wound coaxially with the superconducting winding, at an inner side of the superconducting winding layer.
    Type: Grant
    Filed: November 15, 2013
    Date of Patent: August 2, 2016
    Assignee: KYUSHU UNIVERSITY National University Corporation
    Inventors: Kazuhiro Kajikawa, Kazuo Funaki
  • Publication number: 20140225615
    Abstract: A method for shimming a magnetic field is disclosed. The method uses a single shim current to contribute to suppression of more than one geometrical component of an inhomogeneity in the magnetic field without changing the geometry of the shim path. Apparatuses to implement the method are also disclosed. In embodiments the apparatuses comprise substantially commonly oriented shim paths.
    Type: Application
    Filed: April 22, 2014
    Publication date: August 14, 2014
    Applicant: Nanalysis Corp.
    Inventors: Garett M. Leskowitz, Gregory McFeetors, Sebastien Pernecker
  • Publication number: 20140218031
    Abstract: A magnetic resonance imaging apparatus includes a magnetic assembly including a main magnet and a gradient coil unit and forming a static magnetic field and a gradient magnetic field in the bore thereof, and a gradient controller applying a test gradient waveform to the magnetic assembly, and compensating for a distortion of the magnetic field gradients, caused by eddy currents, by reflecting the actual shape of the applied test gradient waveform.
    Type: Application
    Filed: February 4, 2014
    Publication date: August 7, 2014
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Dae Ho LEE, Seung Je CHOI, Joon Soo KIM
  • Publication number: 20130314087
    Abstract: A magnetic resonance (MR) generating a static (BO) magnetic field of 5 Tesla or higher controller is configured to control an MR scanner to perform an MR sequence (14) including: performing an excitation/localization sub-sequence (30) on a subject disposed in the static (BO) magnetic field generated by the MR scanner to excite 1H polarization in a selected spatial region of the subject; performing 5 a polarization transfer sub-sequence (32) to transfer localized 1H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei; and performing a magnetic resonance spectroscopy (MRS) readout sub-sequence (40) to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject. The polarization transfer sub-sequence includes a pair of phase 10 distortion canceling trapezoidal 180° refocusing pulses (36, 37) operating on the selected species of non-proton nuclei.
    Type: Application
    Filed: January 10, 2012
    Publication date: November 28, 2013
    Applicant: KONINKLIJKE PHILIPS N.V.
    Inventors: Baolian Yang, David Leslie Foxall
  • Patent number: 8456164
    Abstract: Three-dimensional (3D) tomographic image of a target object such as soft-tissue in humans is obtained in the method and apparatus of the present invention. The target object is first magnetized by a polarizing magnetic field pulse. The magnetization of the object is specified by a 3D spatial Magnetic Density image (MDI). The magnetic field due to the magnetized Object is measured in a 3D volume space that extends in all directions Including substantially along the radial direction, not just on a surface as in prior art. This measured data includes additional information overlooked in prior art and this data is processed to obtain a more accurate 3 D image reconstruction in lesser time than in prior art. The methods and apparatuses of the present invention are combined with frequency and phase encoding techniques of Magnetic Resonance imaging (MRI) technique in prior art to achieve different trade-offs.
    Type: Grant
    Filed: November 20, 2010
    Date of Patent: June 4, 2013
    Inventor: Muralidhara Subbarao
  • Patent number: 8350566
    Abstract: In a magnetic particle imaging apparatus that forms an image of a distribution of magnetic particles based on changes in a magnetic flux generated by magnetization of the magnetic particles, modulation coils that magnetize magnetic particles present in a field free area by applying a modulation magnetic field to the field free area, and detection coils are disposed such as to suppress an influence caused by a magnetic flux of the modulation magnetic field applied by the modulation coils and included in a detected magnetic flux.
    Type: Grant
    Filed: June 12, 2008
    Date of Patent: January 8, 2013
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
    Inventors: Shigeharu Ohyu, Motoji Haragashira, Yasuo Sakurai
  • Patent number: 8324900
    Abstract: It is proposed herein to improve the specifications of a low-noise amplifier (LNA) by integrating it in a chip. In order to cover a range of operating frequencies using a single chip, the integrated-circuit amplifier proposed herein comprises an input port configured to receive a magnetic resonance (MR) signal from a radio-frequency (RF) coil, one or more LNAs configured to amplify the received MR signal, and an output port configured to output the amplified MR signal from the one or more LNAs. The operating frequency of the RF coil depends on the field strength. The matching circuit, if present, needs to be tuned to operate at the operating frequency of the RF coil, and depends on the component values in the loop, thus on loop size. In contrast, the proposed integrated-circuit amplifier is capable of directly connecting to RF coils with different loop sizes, without the need for a matching circuit.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: December 4, 2012
    Assignee: Koninklijke Philips Electronic N.V.
    Inventors: Marinus Johannes Adrianus Maria Helvoort, Paulus Cornelius Hendrikus Adrianus Haans, Leo De Vreede
  • Patent number: 8294461
    Abstract: A method for detecting coupled RF current magnetic resonance (MR) objects in a body and determining MR risk is provided. The body is scanned with reverse circularly polarized RF. MR signals generated by coupling of the reverse circularly polarized RF with the RF current MR objects are detected. The detected MR signals are used to determine a risk value.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: October 23, 2012
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: William R. Overall, Greig C. Scott
  • Publication number: 20120256629
    Abstract: Provided is a total electrical nuclear-spin polarization device that is applicable to many narrow-gap semiconductor two-dimensional quantum structures such as InSb with a large g-factor and with a mobility having a normal value. A nuclear-spin polarization device 1 creates a state where the Landau-level separation and the Zeeman-level separation in a sample are equal to each other in a magnetic field, thereby crossing different spin states, and detects nuclear-spin polarization from a resistance change at the crossing point caused by the nuclear-spin polarization.
    Type: Application
    Filed: December 14, 2010
    Publication date: October 11, 2012
    Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY
    Inventors: Hongwu Liu, Kaifeng Yang, Yoshiro Hirayama
  • Patent number: 8229542
    Abstract: A method for correcting image artifacts during the acquisition of magnetic resonance imaging data includes the following steps. At least one part of the linear, location-dependent and spatially constant interference fields arising at the measurement location is determined in a time interval between an excitation point in time and a MR data acquisition point in time.
    Type: Grant
    Filed: February 9, 2007
    Date of Patent: July 24, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventor: Oliver Heid
  • Patent number: 8217653
    Abstract: An RF coil system for magnetic resonance applications includes a multi-channel RF coil transceiver and a multi-channel RF coil. The RF coil system is structured for reconfiguration between a plurality of operational modes.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: July 10, 2012
    Assignee: Regents of the University of Minnesota
    Inventor: J. Thomas Vaughan
  • Publication number: 20120153951
    Abstract: The invention relates to a method for optimization of the performance of a multi-channel coil (1) comprising at least three coil elements, wherein the method comprises the following steps: a) Exciting the coil elements of the multi-channel coil (1) by electrical power signals comprising a specific power, wherein the power of the power signals is partially reflected by the coil elements of the multi-channel coil (1), b) Measuring the power which is reflected by the individual coil elements of the multi-channel coil (1) or by the entire multi-channel coil (1) during excitation of the coil elements, c) Tuning the multi-channel coil (1) depending on the measured reflected power so that the performance of the multi-channel coil (1) is improved, wherein d) all coil elements of the multi-channel coil (1) are simultaneously excited, and e) the reflected power is measured during the simultaneous excitation of all coil elements of the multi-channel coil (1).
    Type: Application
    Filed: September 8, 2009
    Publication date: June 21, 2012
    Applicant: MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V.
    Inventors: Mikhail Kozlov, Robert Turner
  • Patent number: 8198894
    Abstract: An RF coil for MR Imaging that can change a resonance frequency easily and instantaneously in response to a nuclide to be imaged without exchange and adjustment and that also causes only small lowering of sensitivity. The RF coil has a sub coil for changing a resonance frequency of the transmitting/receiving RF coil for transmitting and receiving an MR signal between itself and a nuclide that is an object to be imaged. The sub coil is equipped with a switch, and at the time of switching-on, shifts the resonance frequency of the RF coil by changing an inductance value of the RF coil in a noncontact manner using inductance coupling.
    Type: Grant
    Filed: April 3, 2009
    Date of Patent: June 12, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Kaneko, Hideta Habara, Yoshihisa Soutome, Yosuke Otake, Yoshitaka Bito
  • Publication number: 20120019248
    Abstract: When imaging for sensitivity distribution measurement is performed, a whole-body coil for both transmission and reception and a specified coil used for the present imaging are used as a reception coil, while being switched. The switching of the reception coil is performed by switching between the whole-body coil and the specified coil for each echo in the same encode step. An image created from the echo obtained by the specified coil is divided by an image created from the echo obtained by the whole-body coil to calculate the sensitivity distribution of the specified coil. The sets of data used for the calculation are almost simultaneously obtained, thus providing accurate sensitivity distribution with no influence derived from the movement of a subject. The sensitivity distribution is used to correct the image obtained by the present imaging. Alternatively, the sensitivity distribution is used for the folding operation of parallel imaging.
    Type: Application
    Filed: March 17, 2010
    Publication date: January 26, 2012
    Applicant: Hitachi Medical Corporation
    Inventor: Masayuki Nonaka
  • Patent number: 8046047
    Abstract: Extended-coverage magnetic resonance imaging coils with optimized homogeneity in longitudinal sensitivity are described. One exemplary coil includes four elements, where two of the elements are opposed-solenoid imaging elements and two of the elements are single loop imaging elements.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: October 25, 2011
    Assignee: Case Western Reserve University
    Inventors: Eddy Wong, Claudia Hillenbrand, Jonathan S. Lewin, Jeffrey L. Duerk
  • Patent number: 7957788
    Abstract: Methods and systems for obtaining intravascular magnetic resonance images of blood flow are disclosed. In preferred forms, a train of radio frequency (RF) pulses is produced by an intravascularly introduced RF transmitter positioned in proximate location to the blood flow so as to create a continuous stream of coherently excited protons of the blood flow. The coherently excited protons of the blood flow are sampled as the protons freely precess while flowing through a region of three dimensional space unaffected by the ongoing intravascular RF excitation. An image of the sampled coherently excited protons may then be constructed.
    Type: Grant
    Filed: February 2, 2005
    Date of Patent: June 7, 2011
    Assignee: Duke University
    Inventors: Robert M. Judd, Wolfgang G. Rehwald, Raymond J. Kim
  • Publication number: 20110037468
    Abstract: Featured is a device for NMR or MRI signals from excited nuclei as well as related apparatus, systems and methods. The device includes a strip array antenna including one or more conductor and N reactive tuning components, where N is an integer?1 at least one of the N reactive components is electrically coupled to each of the one or more conductors as well as to ground/virtual ground. The apparent electrical length of the conductors is tuned with the reactive tuning components so it is equal to be about n?/4, where n is an integer?1 and ? is the wavelength of the signal to be detected. The length of the strip also is such as to be substantially in the approximate range of 1.3 times the depth of interest. The strip conductors are also combined with loop coils to form quadrature detectors.
    Type: Application
    Filed: September 10, 2010
    Publication date: February 17, 2011
    Applicant: The Johns Hopkins University
    Inventors: Paul A. Bottomley, Ananda Kumar
  • Publication number: 20100264926
    Abstract: Techniques for designing RF pulses may be configured to produce improved magnitude profiles of the resulting magnetization by relaxing the phase constraint and optimizing the phase profiles. In one embodiment, a spinor-based, optimal control, optimal phase technique may be used to design arbitrary-tip-angle (e.g., large and small tip angle) RF pulses (both parallel transmission and single channel). In another embodiment, small tip angle RF pulses (both parallel transmission and single channel) may be designed using a small-tip-angle (STA) pulse design without phase constraint that is formulated as a parameter optimization problem.
    Type: Application
    Filed: April 16, 2009
    Publication date: October 21, 2010
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Dan Xu, Kevin F. King, Graeme C. McKinnon
  • Publication number: 20100164495
    Abstract: In a non-cartesian sampling method, in order to reduce an artifact on an image caused by an error of a gradient magnetic field, data for correcting the error caused by the gradient magnetic field are obtained when data used for image reconstruction are obtained, and the data used for the image reconstruction are corrected by using the obtained data for the correction. In order to obtain the data for correcting the error, a block having plural parallel echo signals is measured.
    Type: Application
    Filed: June 3, 2008
    Publication date: July 1, 2010
    Inventors: Masahiro Takizawa, Tetsuhiko Takahashi
  • Patent number: 7725160
    Abstract: The present invention is directed to an MRI enhancing device deployable in a body. In one embodiment, the MRI enhancing device is formed of a wire loop and a capacitor that is at least partially formed by the wire used in forming the wire loop.
    Type: Grant
    Filed: August 12, 2002
    Date of Patent: May 25, 2010
    Assignee: Boston Scientific Scimed, Inc.
    Inventor: Jan Weber
  • Patent number: 7725156
    Abstract: In a magnetic resonance tomography apparatus and method for determination of T2-weighted images of tissue with short T2 time, in the framework of a steady-state free precession sequence with non-slice-selective RF excitation pulses and projection-reconstruction methods, in each sequence repetition a first steady-state is read out in the form of a half echo and a second steady-state signal is read out in the form of a further half echo with very short echo times TE1 and TE2=2TR?TE1, and are combined by weighted addition such that an MRT image of tissue with very short T2 time is obtained with the sequence.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: May 25, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventor: Michael Deimling
  • Publication number: 20100033183
    Abstract: This invention provides a receiving coil that allows a high-quality image of high depth sensitivity to be obtained during vertical magnetic field MRI without limiting selection of a cross section to be imaged and of a phase-encoding axis. A subject's field of view is broadened without deterioration of the coil characteristics. Two orthogonal solenoid coils (3-1 and 4-1) and sub-coils (5-1, 6-1, and 7-1) whose sensitivity distributions each become an odd function in an x-direction, a y-direction, and a z-direction, respectively, with respect to the origin of the sensitivity distribution of each of the solenoid coils are used as multiple sub-coils to construct the receiving coil. This receiving coil is suitable for a high-speed imaging method in which an image is acquired using reduced phase encoding and the image is reconstructed using image folding. In addition, the subject's field of view can be broadened by arranging conductors of the coil appropriately.
    Type: Application
    Filed: December 21, 2006
    Publication date: February 11, 2010
    Inventors: Hisaaki Ochi, Masayoshi Dohata, Atsushi Ninomiya, Yoshiyuki Miyamoto
  • Publication number: 20090309596
    Abstract: A magnetic resonance system has a basic magnet system that generates a temporally static, spatially homogeneous basic magnetic field in an examination volume of the magnetic resonance system. At least one radio-frequency system is operated to excite nuclear spins in an examination subject in the examination volume to magnetic resonance, and to detect magnetic resonance signals from the examination subject. An overlay system generates overlay fields in the examination volume. The overlay system has at least one system of the first order and one system of the second order. The system of the first order generates fields that, to a first approximation, exhibit a spatial dependency of the first order. The system of the second order generates fields that, to a first approximation, exhibit a spatial dependency of the second order. A desired gradient and a correction volume are provided to a control device of the magnetic resonance system.
    Type: Application
    Filed: June 17, 2009
    Publication date: December 17, 2009
    Inventor: Thorsten Feiweier
  • Publication number: 20090295388
    Abstract: Remote adjustment of a selected one of a plurality of adjustable NMR probe circuit components is achieved with a plurality of selectable linear actuators, the selected one of which urges a platen against a respective driven gear, azimuthally locked to its shaft, to displace it axially along that shaft. When the driven gear engages a driving gear a single driving motor is energized and controlled to effect the desired adjustment.
    Type: Application
    Filed: May 30, 2008
    Publication date: December 3, 2009
    Inventors: Xiao Zhang, John S. Tobias
  • Publication number: 20090256563
    Abstract: Techniques and systems for magnetic resonance imaging. In one aspect, preparatory pulse sequences precede alternating repetition time steady state free precession (ATR SSFP) pulse sequences to enable image acquisition before reaching a steady-state equilibrium. The design of the preparatory sequences is based on a two step process: First an oscillatory residue is expressed in terms of a window (e.g., a Kaiser-Bessel window) and scale parameters. Second the oscillatory residue is minimized to determine the scale parameters according to a desired application (e.g. ATR SSFP, optimized for fat, water, etc.) The preparation scheme described in this specification can be applied to arbitrary repetition times and RF phase cycling combinations.
    Type: Application
    Filed: March 2, 2009
    Publication date: October 15, 2009
    Applicant: UNIVERSITY OF SOUTHERN CALIFORNIA
    Inventors: Hsu-Lei Lee, Krishna S. Nayak
  • Publication number: 20090237079
    Abstract: The invention relates to a device (1) for magnetic resonance imaging of a body (7), comprising a main magnet (2) for generation of a stationary and substantially homogeneous main magnetic field within the examination zone, a plurality of wireless receiving units (10a, 10b) placed in or near the examination zone, and sampling means (21a, 21b) operating at a variable sampling frequency for sampling the received MR signals and for converting them into digital signal samples.
    Type: Application
    Filed: December 14, 2005
    Publication date: September 24, 2009
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Marinus Johannes Adrianus Maria Van Helvoort, Johannes Petrus Groen, Robert Paul Kleihorst, Cornelis Leonardus Gerardus Ham
  • Patent number: 7573266
    Abstract: In a method for adjustment of the field strength of radio-frequency pulses as well as a magnetic resonance measurement system, radio-frequency pulses are emitted by a radio-frequency antenna of a magnetic resonance measurement system in a magnetic resonance measurement. A test volume slice is initially excited by emission of radio-frequency pulses with a defined pulse amplitude by the appertaining radio-frequency antenna and one-dimensional, spatially-resolved characteristic values are determined along an extent direction of the test volume slice. The one-dimensional, spatially-resolved characteristic values respectively represent a local field strength of the B1 field in strips of the test volume slice running perpendicular to the extent direction. An average value of the determined characteristic values is then formed over at least over one determined segment along the extent direction of the test volume slice.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: August 11, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Thorsten Feiweier, Peter Heubes, Thorsten Speckner
  • Publication number: 20090197093
    Abstract: A method of recovering and recycling solvents, comprising, during printing or coating of solvent-recoverable and recyclable printing ink composition comprising solvents, a step of recovering the solvents vaporized in a solvent recovery apparatus, a step of separating the solvents obtained into one or more single solvents and/or one or more azeotropic compositions of two or more solvents by multi-stage distillation, and a step of recycling them as a printing ink raw material and/or dilution solvent raw material.
    Type: Application
    Filed: June 12, 2007
    Publication date: August 6, 2009
    Applicant: TOYO INK MFG. CO., LTD.
    Inventors: Michihisa Kofuji, Masumi Takano, Hideki Yasuda, Yoshiaki Nakagami, Shinichiro Watanabe, Hiroyuki Kawashima, Yoshimitsu Ishizuka, Toshiyuki Irie
  • Publication number: 20090140738
    Abstract: A method of adjusting an excitation and detection circuit for nuclear magnetic resonance, the circuit comprising a probe (S) of the type comprising a single coil (L) for transmitting pulses to excite the nuclear spins of a sample immersed in a magnetic field and for detecting a resonance signal from said nuclear spins, said method being characterized by a step of tuning the resonant frequency in reception of said circuit to the Larmor frequency (f0) of the nuclear spins of the atoms that are to be detected. An excitation and detection circuit for nuclear magnetic resonance, said circuit being characterized in that it is adapted to implement an adjustment method as described above.
    Type: Application
    Filed: March 14, 2008
    Publication date: June 4, 2009
    Inventors: Herve DESVAUX, Denis Marion
  • Patent number: 7495439
    Abstract: A method for magnetic resonance imaging includes performing a preparatory stage of a MR pulse sequence with an MRI system in which a non-selective RF preparatory pulse is used having a bandwidth such that any spin species having corresponding Larmor frequencies within that bandwidth are affected and the bandwidth is centered at a selected frequency which is offset from a nominal Larmor frequency of the desired spin species being imaged. A time period (TI) elapses during which longitudinal spin magnetization recovers; and then an imaging stage is performed in which an RF excitation pulse is generated to produce transverse spin magnetization of the desired spin species, and in which a set of NMR signals are acquired. An image is reconstructed using the acquired set of NMR signals, and the reconstructed image has reduced artifacts due to B0 field inhomogeneities caused by magnetic susceptibility effects.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: February 24, 2009
    Assignee: The General Hospital Corporation
    Inventor: Christopher John Wiggins
  • Publication number: 20080265886
    Abstract: In a magnetic resonance imaging (MRI) method, in the form of an MRI pulse sequence, and an apparatus for acquiring MRI data from an object, a contrast preparation module is applied to the object for preparing a contrast in the magnetization of nuclear spins of the object, and an imaging module is applied to the object after the contrast preparation module for acquisition of magnetic resonance image data reflecting the prepared contrast. The contrast preparation module includes a train of radio-frequency pulses with the same flip angle magnitude ?, the respective signs of the flip angles alternating from radio-frequency pulse to radio-frequency pulse.
    Type: Application
    Filed: April 25, 2007
    Publication date: October 30, 2008
    Inventor: Jordin D. Green
  • Publication number: 20080204020
    Abstract: A method of magnetic resonance imaging based on rapid acquisition by sequential excitation and refocusing is provided. The method comprises turning on a first time-encoding gradient and applying an excitation pulse in the presence of the first time-encoding gradient. The excitation pulse excites magnetization sequentially along one spatial axis. Thereafter, a first refocusing pulse is applied. A second time-encoding gradient is turned on followed by a second refocusing pulse. A third time-encoding gradient is turned on and a signal is acquired in the presence of the third time-encoding gradient. The third time-encoding gradient sums to zero with the first time-encoding gradient and the second time-encoding gradient for sequential points in space.
    Type: Application
    Filed: October 31, 2007
    Publication date: August 28, 2008
    Inventors: Ryan Chamberlain, Jang-Yeon Park, Michael Garwood
  • Patent number: 7418287
    Abstract: A method of dynamic magnetic resonance imaging comprising acquiring undersampled magnetic resonance signals for successive temporal time slots. In a space spanned by geometrical space and temporal frequency and on the basic of a priori information the aliased difference magnetic resonance data which are gained by subtracting for respective k-space sampling positions data of a baseline magnetic resonance image from the undersampled magnetic resonance signals are decomposed into difference data which essentially pertain to individual spatial positions at individual time slots.
    Type: Grant
    Filed: May 8, 2003
    Date of Patent: August 26, 2008
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jeffrey Tsao, Klaas Paul Pruessmann, Peter Boesiger
  • Publication number: 20080174313
    Abstract: A nuclear magnetic resonance (NMR) method is used to determine a velocity distribution or velocity image of a flowing fluid in a downhole environment. The method comprises applying a radio frequency pulse sequence; applying a magnetic field gradient magnetic field and a gradient pulse duration; measuring a NMR signal; determining a phase characteristic of the NMR signal; and determining the velocity distribution or image of the fluid using the determined phase characteristic, the magnetic field gradient pulse parameters, and a time delay between gradient pulses.
    Type: Application
    Filed: February 20, 2007
    Publication date: July 24, 2008
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventor: Krishnamurthy Ganesan
  • Publication number: 20080116890
    Abstract: A system and method for improving available signal-to-noise ratio (SNR) and speed of MR imaging of hyperpolarized substances is disclosed. The system and method include decoupling spin effects of hydrogen nuclei from non-hydrogen nuclei of interest during sampling of MR signals therefrom. Though the hydrogen nuclei of the hyperpolarized substance may not be directly bonded to the non-hydrogen nuclei of interest, resonance splitting may still impact SNR. Long range decoupling improves T2* time, and thus preserves signal strength and available SNR.
    Type: Application
    Filed: November 21, 2006
    Publication date: May 22, 2008
    Inventor: Ralph E. Hurd
  • Patent number: 7372265
    Abstract: A magnetic resonance imaging (MRI) system includes an examination volume (9), a main magnet system (17) for generating a main magnetic field (B0) in the examination volume, a gradient magnet system (25) for generating gradients of the main magnetic field, and a control system (37) for compensating disturbances of the magnetic field caused by mechanical vibrations of the MRI system. The control system is a feed-forward control system which determines a necessary compensation for said disturbances in dependence on an electric current in the gradient magnet system according to a predetermined response relation. Since in most MRI systems the mechanical vibrations are predominantly caused by the altering electric currents in the gradient magnet system and by eddy currents induced thereby, an accurate and reliable compensation for said disturbances is provided, so that artifacts and other distortions of the reconstructed image caused by said disturbances are considerably reduced.
    Type: Grant
    Filed: January 29, 2004
    Date of Patent: May 13, 2008
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Cornelis Leonardus Gerardus Ham, Wilhelmus Reinerius Maria Mens, Johannes Petrus Groen
  • Patent number: 7275413
    Abstract: A system for determining polarization of a gas comprises a container that contains the polarized gas. An oscillator circuit comprises an Nuclear Magnetic Resonance (NMR) coil that is positioned adjacent to the container. A pulse generator circuit is configured to generate an electrical pulse that may be transmitted to an optical cell through the NMR coil to excite the polarized gas responsive to a control processor. A Q-reduction circuit that is independent of the pulse generator circuit is configured to reduce oscillations in the oscillator circuit from the transmitted electrical pulse responsive to the control processor. A receive circuit is responsive to an electrical signal that is induced in the oscillator circuit due to the electromagnetic excitation of the polarized gas. The control processor is configured to determine the polarization of the gas based on the output signal of the receive circuit.
    Type: Grant
    Filed: November 16, 2005
    Date of Patent: October 2, 2007
    Assignee: Medi-Physics, Inc.
    Inventors: Zivko Djukic, Steve Kadlecek, John Nouls, Ian Nelson, Bastiaan Driehuys