Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes a phase image generating unit, an image value acquisition unit and a frequency shift calculation unit. The phase image generating unit executes a sequence including an application of a bipolar gradient pulse and thereby generates a first phase image. The image value acquisition unit acquires an image value of the first phase image. The frequency shift calculation unit determines an amount of frequency shift per unit amount of gradient magnetic field based on magnetic field strength of the bipolar gradient pulse and on the image value of the first phase image.
Abstract: A radiofrequency antenna has a plurality of channels. A Q-value calculating unit computes reflected signals of the plurality of channels of the radiofrequency antenna, respectively, in a case where transmission signals as electrical signals are simultaneously supplied to the plurality of channels of the radiofrequency antenna, also including a signal obtained when the transmission signal supplied to one channel of the plurality of channels is reflected from another channel, and computes a Q value of the radiofrequency antenna using the reflected signal. An SAR calculating unit calculates a specific absorption rate (SAR) using the Q value.
Abstract: A magnetic resonance imaging configuration and methodology 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 and methodology allows multi-positioning of a patient within the calibrated and more uniform magnetic field lines.
Type:
Grant
Filed:
June 6, 2016
Date of Patent:
January 9, 2018
Inventors:
Raymond V. Damadian, Gordon T. Danby, Hank Hsieh, John W. Jackson, Mark Gelbien, William H. Wahl, Charles A. Green
Abstract: A radio-frequency atomic magnetometer comprises a laser, a photodetector, a vapor chamber, wherein the vapor chamber is in an optical path of laser light between the laser and photodetector, a circular polarizer configured to circularly polarize laser light emitted by the laser, wherein a circularly polarized laser beam is configured to pump into an oriented state, spins of atoms in the vapor chamber and to probe the atoms of the vapor chamber, wherein probing includes detecting a local radio frequency field; and a set of direct current (DC) field coils comprising at least one DC field coil, wherein the set of DC field coils is configured to generate a DC magnetic field oriented at 45 degrees relative to the optical axis of the laser light emitted by the laser and directed toward the vapor chamber; the set of DC field coils further configured to have adjustable DC magnetic field strength.
Abstract: According to one embodiment, a magnetic resonance imaging apparatus provided with a plurality of transmission channels includes a signal processing unit and a control unit. The signal processing unit acquires a radio frequency magnetic field emitted from each of the plurality of transmission channels through a receiver coil mounted on an object and measure a phase of the radio frequency magnetic field. The control unit determines a phase difference between the plurality of transmission channels based on the phase of the radio frequency magnetic field of each of the plurality of transmission channels measured by the signal processing unit. The control unit controls a phase of a radio frequency pulse inputted to each of the plurality of transmission channels, based on the phase difference.
Abstract: Various embodiments are described herein for an apparatus and a method for measuring and characterizing geometric distortions for a region of interest in images obtained using magnetic resonance. The method comprises deriving a computed set of 3D distortion vectors for a set of points within a region of interest covered by a phantom by using harmonic analysis to solve an associated boundary value problem based on boundary conditions derived from a measured set of 3D distortion vectors. The characterized image distortions may be used for various purposes such as for image correction or for shimming, for example.
Abstract: A method includes displaying a position of a distal end of a medical probe that is being navigated in an organ of a patient on a three-dimensional (3D) map of the organ. In response to an event, a plane of interest including the distal end is selected, a real-time Magnetic Resonance Imaging (MRI) slice of the organ is acquired at the selected plane, and the MRI slice is displayed overlaid on the 3D map.
Abstract: A magnetic resonance apparatus corrects higher order B0 magnetic field inhomogeneities in the examination volume of an MR device. Currents through two or more coil sections (X1, X2) of at least one of a plurality of gradient coils (4) are independently controlled in such a manner that higher order field inhomogeneities of the main magnetic field B0 are compensated for by the magnetic field of the at least one gradient coil (4).
Abstract: Systems and methods for spinwave-based metrology in accordance with embodiments of the disclosure involve generating and detecting spinwaves in a sample having a ferromagnetic material; and determining a material thickness, a material integrity measure, a presence of a manufacturing defect, a categorical type of manufacturing defect, and/or a manufacturing process statistic corresponding to spinwave behavior in the sample. In an embodiment, spinwaves are generated by way of concurrent exposure of a target measurement site of the sample to each of a bias magnetic field and radiation (e.g., microwave or radio frequency radiation) produced by a first set of integrated waveguides. A response signal corresponding to a behavior of spinwaves within the target measurement site can be generated by way of a second set of integrated waveguides.
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
Abstract: In a method to determine a complete parameter of a pulse sequence composed of multiple pulse sequence modules for operating a magnetic resonance examination apparatus parameter information of the pulse sequence modules is stored in a memory in leaves and nodes of a tree structure, and the parameter information stored in the tree structure is evaluated to determine the complete parameter of the pulse sequence.
Abstract: The present invention provides a method and apparatus for generating a specific flip angle distribution in magnetic resonance imaging; the method uses a plurality of RF transmission coils combined with linear and nonlinear spatial encoding magnetic fields to generate a homogeneous flip angle distribution.
Type:
Grant
Filed:
July 1, 2014
Date of Patent:
November 28, 2017
Assignee:
NATIONAL TAIWAN UNIVERSITY
Inventors:
Yi-Cheng Hsu, I-Liang Chern, Fa-Hsuan Lin
Abstract: Method for correcting the magnetic field gradient waveform in a magnetic resonance measurement including extracting an impulse response from the measured step response of a magnetic resonance system, determining the slew rate of the system during the step response measurement, modifying the desired output waveform such that the desired output waveform is constrained to within the slew rate and the bandwidth of the system, and determining the required pre-equalized input waveform.
Abstract: An RF coil unit of an embodiment includes a plurality of first coil elements each having a first main loop which receives a magnetic resonance signal and a plurality of second coil elements each having a second main loop and a sub-loop protruding from a portion of the second main loop. Any combination of two coil elements chosen from the plural first coil elements and the plural second coil elements is arranged in an overlap area where areas surrounded by one and another one of the two coil elements overlap in such a way that the overlap area is located in an area surrounded by the first main loop.
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
Abstract: An NMR probe including an RF coil, a sample region defined within the coil, and a thermal control apparatus comprising a thermal control fluid circuit having a thermal control fluid inlet and a thermal control fluid outlet to control the temperature of the sample region.
Abstract: According to some aspects, a method of suppressing noise in an environment of a magnetic resonance imaging system is provided. The method comprising estimating a transfer function based on multiple calibration measurements obtained from the environment by at least one primary coil and at least one auxiliary sensor, respectively, estimating noise present in a magnetic resonance signal received by the at least one primary coil based at least in part on the transfer function, and suppressing noise in the magnetic resonance signal using the noise estimate.
Type:
Grant
Filed:
December 21, 2016
Date of Patent:
October 24, 2017
Assignee:
Hyperfine Research, Inc.
Inventors:
Todd Rearick, Gregory L. Charvat, Matthew Scot Rosen, Jonathan M. Rothberg
Abstract: A method of data acquisition at a magnetic resonance imaging (MRI) system is provided. The system receives at least a portion of raw data for an image, and detects anomalies in the portion of raw data received. When anomalies are detected, the system can correct those anomalies dynamically, without waiting for a new scan to be ordered. The system can attempt to scan the offending portion of the raw data, either upon detection of the anomaly or at some point during the scan. The system can also correct anomalies using digital correction methods based on expected values. The anomalies can be detected based on variations from thresholds, masks and expected values all of which can be obtained using one of the ongoing scan, previously performed scans and apriori information relating to the type of scan being performed.
Type:
Grant
Filed:
September 15, 2014
Date of Patent:
October 24, 2017
Assignee:
SYNAPTIVE MEDICAL (BARBADOS) INC.
Inventors:
Cameron Anthony Piron, Alexander Gyles Panther, Chad Tyler Harris, Stephen B. E. McFadyen
Abstract: Gradient coils are operated to acquire magnetic resonance (MR) signals encoding a first MRI image over a first region inside a main magnet of the MRI system in which at least a portion of a subject is placed, the first region being located within a volume of uniform magnetic field with inhomogeneity below a defined threshold. An active coil is energized to shift the volume of uniform magnetic field such that a second region inside the main magnet of the MRI system is located within the shifted volume of uniform magnetic field, at least a portion of the second region being located outside of the volume of uniform magnetic field before the volume of uniform magnetic field has been shifted. The gradient coil is operated to acquire MR signals encoding a second MRI image over the second region.
Type:
Grant
Filed:
July 15, 2015
Date of Patent:
October 24, 2017
Assignee:
Synaptive Medical (Barbados) Inc.
Inventors:
Geron André Bindseil, Chad Tyler Harris
Abstract: The invention relates to a magnetic field measurement device, including a detector (4) configured to measure the amplitude of an output signal at a harmonic of an oscillation frequency of an excitation source, said amplitude being proportional to the magnetic field (B) to be measured, characterised in that it comprises an excitation circuit configured to associate with a principal excitation source (B1cos?t) oscillating at a principal oscillation frequency at least one secondary excitation source (B2cos(?/3t+?2)) oscillating at a secondary oscillation frequency that is a fraction of the principal oscillation frequency, said fraction being odd if said harmonic is odd, and even if said harmonic is even.
Type:
Grant
Filed:
July 7, 2014
Date of Patent:
October 24, 2017
Assignee:
Commissariat à l'énergie atomique et aux énergies alternatives
Inventors:
Matthieu Le Prado, Francois Bertrand, Marie-Constance Corsi, Elisabeth Delevoye, Sophie Morales