With Conditioning Of Transmitter Signal Patents (Class 324/314)
  • Patent number: 10888247
    Abstract: In a method for filtering magnetic resonance (MR) image data, complex MR image data is acquired from a region to be imaged, and a sliding window averaging is applied to the complex MR image data to generate filtered MR image data. For each window position of the sliding window averaging: a phase variation of the complex MR image data of individual image points of a sliding window is estimated with a model using a linear phase progression, and filtered complex MR image data is generated based on the estimated phase variation of the complex MR image data. The generation of the filtered complex MR image data uses an average formation of the complex MR image data of the individual image points of the sliding window.
    Type: Grant
    Filed: July 26, 2019
    Date of Patent: January 12, 2021
    Assignee: Siemens Healthcare GmbH
    Inventors: Marcel Dominik Nickel, Alto Stemmer
  • Patent number: 10560096
    Abstract: A method for decreasing entropy in a system includes iteratively applying a set of electromagnetic (EM) pulses to the system, the set of EM pulses effect swaps between the following pairs of system energy levels: a first system energy level in which the reset system is in a lowest energy level and the target system is in a first target system energy level that is not a lowest energy level, and a corresponding second system energy level in which the reset system is in a highest energy level and the target system is in a second target system energy level that is next lowest in energy after the first target system energy level, and waiting a time period.
    Type: Grant
    Filed: February 5, 2019
    Date of Patent: February 11, 2020
    Inventors: Sadegh Raeisi, Michele Mosca, Maria Kieferova
  • Patent number: 10520572
    Abstract: A magnetic resonance imaging apparatus comprises a scanning unit for performing a pulse sequence PS including a MT (Magnetization Transfer) pulse b for lessening signals from the cerebral parenchyma (white matter and gray matter). The scanning unit performs the pulse sequence PS in periods of time P1 and P3 in the pulse sequence PS so that the MT pulse b is applied every repetition time TR, while it performs the pulse sequence PS in a period of time P2 in the pulse sequence PS so that no MT pulse b is applied.
    Type: Grant
    Filed: December 21, 2015
    Date of Patent: December 31, 2019
    Inventors: Mitsuharu Miyoshi, Naoyuki Takei
  • Patent number: 10429464
    Abstract: In a magnetic resonance apparatus having a scanner that generates a basic magnetic field in an imaging volume, and an operating method to acquire data from an entirety of a recording volume, wherein the scanner has a global shim coil acting on the entire imaging volume, and a local shim coil acting, with the global shim coil, on a sub-volume containing a region of interest, a first adjustment volume is established that contains the recording volume. A smaller, second adjustment volume is established containing the region of interest, and at most, the sub-volume. Using a field map of the basic magnetic field that covers the first adjustment volume, shim currents are respectively identified for the global shim unit, for homogenizing the first adjustment volume, and for the local shim unit, for homogenizing the second adjustment volume, accounting for the effect of the first shim currents on the second adjustment volume.
    Type: Grant
    Filed: February 22, 2018
    Date of Patent: October 1, 2019
    Assignee: Siemens Healthcare GmbH
    Inventors: Daniel Niederloehner, Dominik Paul
  • Patent number: 10422843
    Abstract: In a method and magnetic resonance apparatus for modification of a magnetic resonance actuation sequence, a parameter of the magnetic resonance actuation sequence is specified that, is categorized in one of a number of predefined categories for this parameter to which a boundary condition is linked. The boundary condition is taken into account and observed during the determination of a property of the pulses to be activated.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: September 24, 2019
    Assignee: Siemens Healthcare GmbH
    Inventors: David Grodzki, Dominik Paul
  • Patent number: 10408909
    Abstract: The present invention relates to a medical apparatus which includes a motion mechanism which has at least one degree of freedom, an actuator configured to drive the motion mechanism and a control unit configured to control the actuator, and which operates in a magnetic field environment of an MRI, the medical apparatus including: a data storage unit in which data related to magnetic susceptibility of the actuator is stored; a calculating unit configured to calculate information related to an influence which the actuator exerts upon the magnetic field environment by calculation based on the magnetic susceptibility; and a communication unit configured to output the information to the MRI. An influence which an apparatus which operates in a strong magnetic field environment exerts upon an MR image can be reduced.
    Type: Grant
    Filed: May 22, 2013
    Date of Patent: September 10, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takeshi Iwasa
  • Patent number: 10386431
    Abstract: A magnetic resonance tomography system has a frequency control device for temperature compensation, a temperature sensor, and a high frequency generator. An output frequency of an output signal from the high frequency generator is dependent on a value of a digital frequency variable, and a synthesis signal with the system frequency is generated dependent on the output signal. A temperature change is detected using the temperature sensor, a temperature-time function of the temperature is determined using the temperature change that has been detected, a time is determined at which a change in the digital frequency variables in the least significant bit brings about a change in the frequency of the synthesis signal that corresponds with a change in the system frequency due to a temperature, according to the interpolated temperature-time function, and the digital frequency variable in the least significant bit is changed at the specified time.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: August 20, 2019
    Assignee: Siemens Healthcare GmbH
    Inventors: Rudi Baumgartl, Andrew Dewdney
  • Patent number: 10371769
    Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes a static field magnet, a gradient coil, at least one radio frequency coil, a receiver and processing circuitry. The static field magnet, the gradient coil, the at least one radio frequency coil and the receiver are configured to acquire magnetic resonance signals from an object. The processing circuitry is configured to generate magnetic resonance image data based on the magnetic resonance signals. The receiver is configured to convert analog magnetic resonance signals received by the at least one radio frequency coil into digital magnetic resonance signals without a downconversion; separate the digital magnetic resonance signals into in-phase signals and quadrature-phase signals; and perform filter processing for removing noises of the in-phase signals and the quadrature-phase signals.
    Type: Grant
    Filed: June 12, 2015
    Date of Patent: August 6, 2019
    Inventors: Kazuyuki Soejima, Sojuro Kato, Makoto Hirama
  • Patent number: 10359482
    Abstract: A method of acquiring an image in an MRI system includes dividing a scannable region of an object into regions, determining a coil to be used for the divided regions, receiving signals from the determined coil via signal channels connected to the determined coil and grouped by using a switching device, and acquiring the image from the received signals.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: July 23, 2019
    Inventor: Hak-soo Chon
  • Patent number: 10295637
    Abstract: There is provided a scan condition determining apparatus, comprising: setting means for setting values of a plurality of parameters different from a repetition time and different from a bandwidth; and determining means for determining a specific value of the bandwidth based on the set values of the plurality of parameters such that a repetition time determined as a longer one of a first period of time and a second period of time is minimized, the first period of time being a time taken to perform a pulse sequence in one cycle, and the second period of time being a time taken from the start of a pulse sequence in one cycle until a pulse sequence in a next cycle is ready to perform determined by the thermal design restrictions of a gradient coil.
    Type: Grant
    Filed: January 29, 2016
    Date of Patent: May 21, 2019
    Assignee: General Electric Company
    Inventors: Yoshihiro Tomoda, Masanori Ozaki
  • Patent number: 10295622
    Abstract: A method for signaling a tuning of an adjustment parameter of an antenna coil arrangement of a magnetic resonance tomograph includes detecting a deviation between an actual adjustment value of at least one adjustment parameter and a required adjustment value of the at least one adjustment parameter. As a function of the deviation, an acoustic and/or a mechanical signal is output in real time to an operator. A device for signaling a tuning of an adjustment parameter of a coil arrangement of a magnetic resonance tomograph, and a magnetic resonance tomograph operating according to the method and/or containing the device are described.
    Type: Grant
    Filed: March 6, 2015
    Date of Patent: May 21, 2019
    Assignee: Siemens Aktiengesellschaft
    Inventors: Razvan Lazar, Paul Yoe
  • Patent number: 10281546
    Abstract: In magnetic resonance tomography apparatus and operating a method, a magnetic resonance control sequence with a dynamic magnetic field gradient is optimized in computer, based on an image basis and a gradient basis. A basis transformation of the dynamic magnetic field gradient from the image basis into the gradient basis is implemented, and the dynamic magnetic field gradient in the gradient basis is optimized and is emitted from the computer in an optimized magnetic resonance control sequence.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: May 7, 2019
    Assignee: Siemens Healthcare GmbH
    Inventor: David Grodzki
  • Patent number: 10222505
    Abstract: In some embodiments, an apparatus, system, and method may operate to transmit, using a first transceiver antenna, a common signal into a geological formation, and to receive in response to the transmitting, at the first transceiver antenna, a first corresponding nuclear magnetic resonance (NMR) signal from a first volume of the formation. Additional activity may include receiving, in response to the transmitting, at a second transceiver antenna spaced apart from the first transceiver antenna, the common signal transformed by the formation into a received resistivity signal, as well as transmitting, using the second transceiver antenna, a second corresponding NMR signal into a second volume of the formation different from the first volume of the formation. Additional apparatus, systems, and methods are disclosed.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: March 5, 2019
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Arcady Reiderman, Songhua Chen
  • Patent number: 10156622
    Abstract: In a method, magnetic resonance apparatus, and pulse optimization computer for determining a pulse sequence for radial sampling of k-space in magnetic resonance imaging, the amplitudes and the increases with respect to time of readout gradients and phase gradients for individual sections of k-space are determined depending on an orientation of the respective section in k-space and depending on global maximum values of the amplitudes and the increases of the gradients on the physical axes.
    Type: Grant
    Filed: March 8, 2017
    Date of Patent: December 18, 2018
    Assignee: Siemens Healthcare GmbH
    Inventors: David Grodzki, Thorsten Speckner
  • Patent number: 10156621
    Abstract: A magnetic resonance system (1) includes at least one radio frequency (RF) transmit coil (6), an RF transmitter (34), an anthropometric unit (28), and an adaptive SAR unit (40). The at least one radio frequency (RF) transmit coil (6) transmits measured RF power to excite and manipulate magnetic resonance in tissues of a subject (57) in an examination region. The RF transmitter (34) controls the amount of transmitted RF power based on a specific absorption rate (SAR) for an imaging sequence. The anthropometric unit (28) determines a mass of a portion of the subject which receives the transmitted RF power based on a determined total mass. The adaptive SAR unit (40) adjusts a selected scan sequence based on the SAR parameters determined from the measured transmitted RF power and a measured reflected power, achieved IB|+I field, the mass of the portion of the subject which receives the transmitted RF power and applicable SAR parameter models stored in a SAR reference unit (46).
    Type: Grant
    Filed: September 17, 2013
    Date of Patent: December 18, 2018
    Inventors: Zhiyong Zhai, Michael Andrew Morich
  • Patent number: 10145920
    Abstract: Magnetic resonance imaging (MRI) systems and methods for determining and adjusting TI using single-line acquisition and automatic compartment detection. A method includes positioning a readout line of the MRI scanner through a compartment of interest of a region of interest in a subject. The method includes inverting magnetization within the readout line by playing an inversion pulse; and reading out data along the readout line after play of the inversion pulse. The method also includes determining a T1 value for each pixel along the readout line; determining the pixels that belong to first and second portions within the compartment of interest; determining a T1 value of each of the first and second portions by averaging the pixels within each portion; and determining an inversion time based on the determined T1 values such that the compartment of interest has a desired magnetization in an image to be acquired.
    Type: Grant
    Filed: January 26, 2016
    Date of Patent: December 4, 2018
    Assignee: Duke University
    Inventors: Wolfgang Rehwald, Elizabeth Jenista, Raymond Kim, David Wendell
  • Patent number: 10088594
    Abstract: A nuclear magnetic resonance (NMR) system includes a transmitter of an NMR tool to output a magnetic field pulse into a zone of interest, a receiver of the NMR tool to output an NMR echo data set produced from an interaction of the magnetic field pulse and the zone of interest, and an NMR echo processing module including a filter matched to a response of the NMR tool to output a filtered NMR echo data set from the NMR echo data set, wherein the filter is matched to an echo shape of the NMR echo data, is matched to an average of a selected signal spectra of the NMR echo data set, or dynamically changes in response to a measurement.
    Type: Grant
    Filed: October 16, 2014
    Date of Patent: October 2, 2018
    Inventors: Jeffrey L. Paulsen, Martin D. Hurlimann, Julius Kusuma, Brian E. Boling, Soumyajit Mandal, Brian Gaddis
  • Patent number: 10060962
    Abstract: A system and method for tuning a transformer is provided. A transformer fixture may connect a switching network to a plurality of inductors of a transformer. At least one computing device may calculate a target number of turns for a primary coil and a secondary coil of the transformer based on a frequency response of the transformer. The switching network may connect the inductors of the transformer together in a pattern that results in the primary coil and secondary coil having the target number of turns.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: August 28, 2018
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Josue Kure, Timothy Gomez, Patrick Arvin
  • Patent number: 10048332
    Abstract: In one embodiment, an MRI apparatus (20) includes “a temperature measuring unit (70A to 70D) performing temperature measurement of a gradient magnetic field coil unit (26)”, a data storing unit (100), a pulse setting unit (102), and an imaging unit. The data storing unit stores the first and second data indicating a shift of a center frequency of magnetic resonance of hydrogen atoms. The first data corresponds to a case of temperature rise of the gradient magnetic field coil unit, and the second data corresponds to a case of temperature fall of that. The pulse setting unit corrects a center frequency of an RF pulse by calculating an estimated shift of the center frequency based on data corresponding to result of the temperature measurement out of the first and second data. The imaging unit performs magnetic resonance imaging based on the corrected RF pulse.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: August 14, 2018
    Inventor: Kazuhiro Sueoka
  • Patent number: 9804236
    Abstract: A magnetic resonance imaging (MRI) apparatus and a method of generating an MR image that may be generated in a resource saving mode by taking into account energy efficiency. The method includes: setting a resource saving mode; acquiring, based on the set resource saving mode, at least one description corresponding to a plurality of imaging filters; and generating a first MR image based on the acquired at least one description.
    Type: Grant
    Filed: December 7, 2015
    Date of Patent: October 31, 2017
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Keum-yong Oh, Su-jin Kim, Sung-pil Jung, Yang-lim Choi
  • Patent number: 9759791
    Abstract: The MRI apparatus includes a main magnet forming a static magnetic field in a bore, and a gradient coil assembly which forms a magnetic field gradient in the static magnetic field and includes a plurality of shim trays arranged therein at a predefined interval and at least one first shim token provided between the shim trays.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: September 12, 2017
    Inventors: Oh Soo Kwon, Dong Keun Park, Jun Suk Kwak
  • Patent number: 9470767
    Abstract: Apparatus, methods, and other embodiments associated with wireless magnetic field monitoring (wMFM) in magnetic resonance imaging (MRI) are described. One example apparatus includes a wMFM module configured to receive an MFM signal from an MFM probe and to wirelessly transmit modulated MFM signals produced from the received MFM signals to an MRI apparatus. The MRI apparatus is configured with a wireless receiver that receives and processes the modulated MFM signals into information used in an image reconstruction. The MRI apparatus includes an MRI reconstruction logic configured to produce an MR image from the MRI signal based, at least in part, on the magnetic field measurement information.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: October 18, 2016
    Assignee: Case Western Reserve University
    Inventors: Mark Griswold, Matthew Riffe
  • Patent number: 9405035
    Abstract: An enhanced radio frequency transmitter suitable for use in a nuclear magnetic resonance logging tool, may employ a power amplifier that comprises two pairs of switching amplifiers and a summation stage. The first pair of switching amplifiers together generate a first pair of pulse sequences having an adjustable phase difference, while the second pair of switching amplifiers generate a second pair of pulse sequences, each pulse sequence in the second pair being provided a fixed phase offset from a respective pulse sequence in the first pair. The summation stage forms a combined signal from the pulse sequences in both said first and second pairs. The fixed phase offset operates to at least partly cancel a higher harmonic of the pulse sequences from the combined signal, thereby reducing energy losses downstream from the transmitter.
    Type: Grant
    Filed: January 10, 2012
    Date of Patent: August 2, 2016
    Inventor: Alexey Tyshko
  • Patent number: 9395431
    Abstract: A series of MR image frames are acquired that depict a subject's heart at successive cardiac phases. Delayed enhancement of infarcted myocardium is depicted in some of the image frames by administering a contrast agent prior to data acquisition. Data acquisition is performed in a single breath hold by producing an RF inversion pulse followed by segments of SSFP pulse sequences during a succession of cardiac gated heart beats. The acquired MR image frames depict contrast between blood, viable myocardium and nonviable myocardium, and they depict left ventricle wall thickness and wall thickening throughout the cardiac cycle.
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: July 19, 2016
    Inventors: Jay S. Detsky, Graham A. Wright
  • Patent number: 9385798
    Abstract: Method and apparatus for generating channelized hardware-independent waveforms include: generating metadata associated with a waveform, the metadata including a frequency list, a phase list and amplitude information, wherein the metadata is generated independent of a number of channels; interpreting the metadata to generate channel select, frequency, phase and amplitude parameters; providing the frequency, phase and amplitude parameters to a direct digital synthesizer (DDS) to generate a digital signal; providing the channel select parameter to a channel selector to generate a plurality of channelized waveforms from the generated digital signal; and transmitting the plurality of channelized waveforms over a plurality of communication channels.
    Type: Grant
    Filed: January 27, 2015
    Date of Patent: July 5, 2016
    Inventors: Harry Marr, Ian S. Robinson, Ray T. Hsu
  • Patent number: 9261470
    Abstract: High precision elemental concentration determination is achieved using a nuclear magnetic resonance device that can continuously monitor samples of a source fluid in the field and in the refinery plant while the source fluid is refined into a desired product fluid.
    Type: Grant
    Filed: March 7, 2014
    Date of Patent: February 16, 2016
    Inventors: Pablo Prado, Andrew McDowell, James Chepin
  • Patent number: 9229072
    Abstract: A method for checking a high-frequency transmit device of a magnetic resonance tomography system, excitation vectors that represent high-frequency signal strengths on the individual transmit channels are determined for a plurality of time points or time periods. High-frequency exposure values absorbed in an examination object are determined in accordance with predetermined check rules on the basis of the excitation vectors. The high-frequency transmit device is restricted in function when an exposure check value that is based on at least one high-frequency exposure value reaches or exceeds a predetermined limit check value. The check rules are predetermined as a function of a current transmit mode of the high-frequency transmit device. The respective transmit mode of the high-frequency transmit device is verified on the basis of the excitation vectors. When a transmit mode change is detected, the check rules are changed, and/or the high-frequency transmit device is restricted in function.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: January 5, 2016
    Assignee: Siemens Aktiengesellschaft
    Inventor: Matthias Gebhardt
  • Patent number: 9084553
    Abstract: In a method for acquisition of magnetic resonance images of the heart, MR signals of the heart are acquired using an imaging sequence, wherein the magnetization is inverted by an RF inversion pulse before the acquisition of the MR signals; and of the heart activity is detected, and the point in time of the switching of the RF inversion pulse dependent on the detected heart activity.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: July 21, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: Carsten Warmuth
  • Patent number: 9081055
    Abstract: A method for reducing local specific absorption rate (“SAR”) during imaging of a subject with a magnetic resonance imaging (“MRI”) system is provided. A radio frequency (“RF”) excitation pattern is selected for an RF coil array to be used during the imaging. In this RF excitation pattern, locations in which local SAR exceeds a preselected threshold value are identified. Examples of threshold values include regulatory limits on local SAR. Using the identified local SAR hotspot locations, a cancellation electric field pattern that is defined by so-called “dark modes” of the coil array is determined. Imaging of the subject commences using the RF coil array and the MRI system, in which the RF coil array is used to simultaneously produce an RF excitation field and a cancellation electric field using the respective field patterns. This simultaneous production of the RF excitation and cancellation electric fields reduces local SAR at the hotspot locations.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: July 14, 2015
    Inventors: Lawrence L Wald, Kawin Setsompop
  • Patent number: 9041394
    Abstract: A magnetic resonance imaging apparatus according to an embodiment includes an executing unit, a calculating unit, and a correcting unit. The executing unit executes a first pre-scan in which a readout gradient magnetic field and a phase encoding gradient magnetic field are not applied and sampling gradient magnetic fields is applied in a phase encoding direction and a second pre-scan in which the readout gradient magnetic field is not applied, the sampling gradient magnetic field is applied at the same echo signal as that in the first pre-scan, and a representative phase encoding gradient magnetic field in a main scan. The calculating unit calculates the amount of correction from phase differences between the echo signals collected by the first pre-scan and between the echo signals collected by the second pre-scan. The correcting unit corrects the pulse sequence for the main scan on the basis of the calculated amount of correction.
    Type: Grant
    Filed: May 31, 2011
    Date of Patent: May 26, 2015
    Inventor: Masaaki Umeda
  • Patent number: 9041395
    Abstract: A method for producing magnetic resonance images of a subject in which artifacts resulting from a localized source, such as from pulsatile blood flow, are substantially mitigated is provided. The location of an artifact source, at which spins corresponding to flowing blood are located, is identified. Using this identified artifact source location, a region-of-saturation is calculated. A magnetic resonance imaging (MRI) system is then directed to perform a pulse sequence that results in the generation of a radio frequency (RF) saturation field being produced by an array of RF transmission coils. The RF saturation field is sized and shaped according to the calculated region-of-saturation. Images are reconstructed from image data acquired after application of the RF saturation field, and artifacts related to motion of the spins at the identified location of the artifact source are substantially mitigated in these images.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: May 26, 2015
    Assignee: The General Hospital Corporation
    Inventor: Alma Gregory Sorensen
  • Publication number: 20150123660
    Abstract: A progressive series of five new coils is described. The first coil solves problems of transmit-field inefficiency and inhomogeneity for heart and body imaging, with a close-fitting, 16-channel TEM conformal array design with efficient shield-capacitance decoupling. The second coil progresses directly from the first with automatic tuning and matching, an innovation of huge importance for multi-channel transmit coils. The third coil combines the second, auto-tuned multi-channel transmitter with a 32-channel receiver for best transmit-efficiency, control, receive-sensitivity and parallel-imaging performance. The final two coils extend the innovative technology of the first three coils to multi-nuclear (31P—1H) designs to make practical human-cardiac imaging and spectroscopy possible for the first time at 7 T.
    Type: Application
    Filed: October 7, 2014
    Publication date: May 7, 2015
    Inventors: J. Thomas Vaughan, JR., Charles A. Lemaire
  • Patent number: 8988075
    Abstract: A method is disclosed for suppressing and/or eliminating noise signals during magnetic resonance imaging by way of a magnetic resonance sequence including an ultra-short echo time. In at least one embodiment, the method includes a recording step for recording magnetic resonance signals of an object to be examined, especially a partial region of a patient, by way of the magnetic resonance sequence, wherein in a noise signal determination step at least one item of information about at least one noise signal of a noise element, especially of a magnetic resonance antenna element, is made available.
    Type: Grant
    Filed: September 28, 2011
    Date of Patent: March 24, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: David Grodzki
  • Patent number: 8975895
    Abstract: A method for correcting motion-induced phase errors in diffusion-weighted k-space data acquired with a magnetic resonance imaging (MRI) system is provided. The MRI system is directed to acquire the following data from an imaging volume: three-dimensional diffusion-weighted k-space data, three-dimensional diffusion-weighted navigator data, three-dimensional non-diffusion-weighted k-space data, and three-dimensional non-diffusion-weighted navigator data. Initial estimates of k-space shift values and a constant phase offset value are calculated using the three-dimensional diffusion-weighted navigator data and the three-dimensional non-diffusion-weighted navigator data. These initial k-space shift values and constant phase offset value are then updated by iteratively minimizing a cost function that relates the phase of the diffusion-weighted k-space data to the phase of the non-diffusion-weighted k-space data, as shifted by the initial k-space shift values and constant phase offset value.
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: March 10, 2015
    Assignee: The Board of Trustees of the University of Illinois
    Inventors: Bradley Sutton, Anh Van, Diego Hernando
  • Publication number: 20150022203
    Abstract: In order to configure a transmission coil of a magnetic resonance imaging (MRI) system without taking a specific measurement object into account, the transmission coil is automatically detected and identified when the transmission coil is connected to the MRI system. A phase setting of a pulse to be transmitted by the detected transmission coil is identified based on at least the identified type of the transmission coil. The transmission coil is excited with the pulse having the identified phase and amplitude.
    Type: Application
    Filed: July 31, 2013
    Publication date: January 22, 2015
    Inventors: Rene Gumbrecht, Holger Adolf, Thomas Benner, Hans-Peter Fautz, Jörg Ulrich Fontius
  • Patent number: 8928319
    Abstract: In a magnetic resonance (MR) apparatus and an operating method for the apparatus, image distortions are corrected that occur in exposures of diffusion-weighted MR images of an examination subject. A diffusion-weighted image is acquired using a first acquisition process. Another diffusion-weighted reference image is acquired using a second acquisition process that is different than the first acquisition process. The second acquisition process causes significantly smaller eddy current-dependent image distortions than the first acquisition process given the same b-value. Correction parameters to correct the image distortions of the diffusion-weighted image are determined by comparing the diffusion-weighted image with the reference image in order to determine the correction parameters such that the diffusion-weighted image can be converted into the reference image with the aid of the correction parameters.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: January 6, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: Thorsten Feiweier
  • Patent number: 8928320
    Abstract: In the acquisition of magnetic resonance data from an examination subject according to a pulse sequence that causes radiation into the examination subject of a radiated radio frequency (RF) pulse having a frequency spectrum and a slice profile with a relationship therebetween, the examination subject is substantially simultaneously, with the radiated RF pulse, to a non-linear magnetic field that alters the relationship in the radiated RF pulse between the frequency spectrum and the slice profile. The alteration of this relationship can be used, for example, to reduce the specific absorption rate (SAR) of the examination subject during the acquisition of the magnetic resonance data.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: January 6, 2015
    Inventors: Emre Kopanoglu, Ergin Atalar
  • Patent number: 8907673
    Abstract: For magnetic resonance imaging (MRI), a dynamic frequency drift correction method for binomial water excitation method includes collecting the reference one-dimensional navigation signal by an MRI device; acquiring one current one-dimensional navigation signal after scanning N images, wherein N is a positive integer; calculating the frequency drift according to the reference one-dimensional navigation signal and the current one-dimensional navigation signal; calculating and setting the initial phase of the next radio frequency signal by the MRI device according to the frequency drift.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: December 9, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Qiang He, De He Weng, Xiao Dong Zhou
  • Patent number: 8890528
    Abstract: A RF power transmitter (100) includes an RF synthesizer (104) that generates an analog RF signal based on a digital description of the desired RF waveform and digital feedback signals and a power module (116) that amplifies the analog RF signal and provides the amplified analog RF signal (122) to a load (102).
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: November 18, 2014
    Assignee: Analogic Corporation
    Inventors: Adrian Delforge, Louis Poulo
  • Patent number: 8866478
    Abstract: In a magnetic resonance apparatus and operating method therefor, and in a processor that is programmed to design RF pulses for operating such a magnetic resonance apparatus, the RF pulses are designed to mitigate off-resonance effects caused by inhomogeneity of the basic (B0) magnetic field in the magnetic resonance apparatus. The RF pulses of a parallel transmit array are designed with different spatial phase distributions, that deviate from a constant phase from pulse-to-pulse, with the absolute value of the difference between respective spatial phase distributions of any two successively radiated RF pulses corresponding to the off-resonance that is caused by B0-inhomogeneity during the time between the radiation of the successive pulses.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: October 21, 2014
    Assignees: Siemens Aktiengesellschaft, The General Hospital Corp., Massachusetts Institute of Technology
    Inventors: Elfar Adalsteinsson, Hans-Peter Fautz, Kawin Setsompop, Lawrence Wald
  • Publication number: 20140306708
    Abstract: A magnetic resonance apparatus including transmission antennas that may be actuated in parallel by a control device of the magnetic resonance apparatus may be operated in a group mode. In the group mode, the transmission antennas are grouped into groups of transmission antennas. The actuation signals of transmission antennas within the respective group are in a respectively predefined relationship relative to one another. A respective group actuation signal for each of the groups of transmission antennas is prescribed for the control device by an operator. The control device carries out checks as to whether a group exposure value established based on the group actuation signals lies below a maximum admissible group exposure limit. If this is the case, the control device establishes the actuation signals for the individual transmission antennas based on the group actuation signals. If this is not the case, the control device carries out another measure.
    Type: Application
    Filed: April 10, 2014
    Publication date: October 16, 2014
    Inventors: Hans-Peter Fautz, Matthias Gebhardt, Franz Schmitt
  • Publication number: 20140300359
    Abstract: In accordance with various embodiments, a radio frequency (RF) coil array for use in a magnetic resonance imaging (MRI) system includes at least first and second RF coils. Each of the RF coils have a main body loop configured to at least one of transmit or receive RF energy at an operating imaging frequency in connection with acquiring MRI image data for an MRI system. The RF coil array also includes first and second cables configured to electrically couple the first and second RF coils, respectively, to a system interface. The RF coil array also includes a common ground connection between the first and second cables. The common ground connection is selectively positioned at a grounding point along lengths of the first and second cables to form a ground loop having a select self-resonance frequency (SRF) that differs from the imaging frequency of the MRI system.
    Type: Application
    Filed: April 25, 2014
    Publication date: October 9, 2014
    Applicant: General Electric Company
    Inventors: Thomas Grafendorfer, Fraser Robb, Greig Scott, Shreyas Vasanawala
  • Publication number: 20140292327
    Abstract: Example systems, apparatus, circuits, and other embodiments described herein concern parallel transmission in MRI. One example apparatus includes at least two enhanced mode gallium nitride (eGaN) based field effect transistors (FETs) that are connected by a coil that includes an LC (inductance-capacitance) leg. The apparatus includes a controller that inputs a signal to the eGaN FETs to control the production of an output analog radio frequency (RF) signal. The LC leg selectively alters the output analog RF signal. The analog RF signal is used in parallel magnetic resonance imaging (MRI) transmission. One embodiment provides an MRI transmit coil with switched-mode current-source amplification provided by a gallium nitride FET.
    Type: Application
    Filed: October 14, 2013
    Publication date: October 2, 2014
    Inventors: Mark Griswold, Michael Twieg
  • Patent number: 8836328
    Abstract: NMR measurements are made along with acoustic measurements using one tool. The antenna of the NMR sensor is used to create acoustic signals. Interference between the acoustic and NMR measurements is avoided due to the frequency difference, and by having the acoustic excitation during a wait time of the NMR pulse sequence.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: September 16, 2014
    Assignee: Baker Hughes Incorporated
    Inventor: Thomas Kruspe
  • Patent number: 8829903
    Abstract: An MRI apparatus includes a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, an RF coil assembly having at least a first port and a second port, an RF transceiver system having a pulse module and configured to transmit RF signals to the first port and the second port, and a computer programmed to drive the RF coil assembly in quadrature through the at least first port and the second port, measure a B1 field using at least one flux probe at two or more angular orientations within the RF coil assembly, and characterize and optimize performance of the MRI system based on the measurements of the B1 field.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: September 9, 2014
    Assignee: General Electric Company
    Inventors: Bijay Kamleshbhai Shah, Eddy Benjamin Boskamp, Ricardo Becerra
  • Publication number: 20140232396
    Abstract: In a method and a pulse sequence optimization device to determine a pulse sequence for a magnetic resonance system, a pulse sequence is selected for optimization that includes a number of radio-frequency pulses and a number of gradient pulses chronologically coordinated therewith. An automatic analysis of the pulse sequence takes place to identify fixed point/time periods in the pulse sequence that are to be left unmodified, and modifiable time intervals in the pulse sequence that may be optimized. An automatic optimization of gradient pulses in the modifiable time intervals takes place according to a predetermined optimization criterion, while keeping the length of modifiable time intervals constant.
    Type: Application
    Filed: February 18, 2014
    Publication date: August 21, 2014
    Inventors: David Grodzki, Bjoern Heismann
  • Publication number: 20140232397
    Abstract: In a method and a pulse sequence determination device to determine a pulse sequence for a magnetic resonance system, control protocol parameter values are initially acquired. A determination of k-space trajectory node points within k-space then takes place in a processor on the basis of the control protocol parameter values. The determination of the pulse sequence then takes place on the basis of the k-space trajectory node points. A method for operating a magnetic resonance system uses such a pulse sequence, and a magnetic resonance system embodies such a pulse sequence determination device.
    Type: Application
    Filed: February 18, 2014
    Publication date: August 21, 2014
    Inventors: David Grodzki, Bjoern Heismann
  • Patent number: 8797032
    Abstract: The temperature of an MRI gradient magnetic field coil unit is measured at least two times. Shift data indicating a center magnetic resonance frequency of a hydrogen atom in response to variation of the gradient coil temperature is stored in advance. Estimated shift of the center frequency based on the measurement result is determined and the center frequency of an RF NMR excitation pulse is corrected based on the estimated shift.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: August 5, 2014
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems Corporation
    Inventor: Masashi Ookawa
  • Patent number: 8786282
    Abstract: In a method to control a magnetic resonance device for image acquisition in at least one slice, the magnetic resonance device has a radio-frequency antenna with multiple transmission channels. At least one slice deviates from a cuboid shape and/or that is roughly adapted to a target volume of interest that is to be acquired, and/or at least one saturation volume adapted to a shape in a subject to be acquired, are defined automatically and/or manually via a user interface. The selection of possible slices and/or saturation volumes is limited automatically under consideration of the technical embodiment of the radio-frequency antenna. The image acquisition takes place in the selected slice and/or under consideration of the saturation volume.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: July 22, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stefan Scholl
  • Patent number: 8779771
    Abstract: In a magnetic resonance marking system marking a flowing medium in a marking region, as well as in a magnetic resonance system with such a magnetic resonance marking system, a method to control a magnetic resonance marking system, and a method to generate magnetic resonance exposures, a radio-frequency transmission device generates marking radio-frequency signals, and a marking radio-frequency transmission coil emits the marking radio-frequency signals in the marking region. A magnetic field determination device determines a magnetic field strength in the marking region, and a control unit derives a marking transmission frequency from the determined magnetic field strength and to control the radio-frequency transmission device so that marking radio-frequency signals at the derived marking transmission frequency are emitted by the marking radio-frequency transmission coil.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: July 15, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bjoern Heismann, Sebastian Schmidt, Markus Vester, Anke Weissenborn