Abstract: In a method and system for acquiring measurement data reference data for a phase correction of the measurement data, a RF excitation pulse is provided to excite spins in the object under examination, one or more RF refocusing pulses are provided to refocus the spins excited by the RF excitation pulse, measurement data is acquired by recording echo signals of refocused spins excited by the RF excitation pulse by switching readout gradients that alternate in their polarity, at least two echo signals are recorded while switching readout gradients with different polarity acquire reference data, chronologically between the providing of the RF excitation pulse and the acquisition of the measurement data, and correction data is determined for phase correction of phase errors contained in the measurement data based on the acquired reference data.
Abstract: A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry configured, on a basis of one or both of (A) a parameter related to applying one of inversion and flip pulses and (B) an intensity of a slice selecting gradient magnetic field applied together with the one of the pulses in relation to selecting a slice to which the one of the pulses is applied, to determine one or both of (A) a parameter related to applying the other of the inversion and (B) flip pulses; and an intensity of the slice selecting gradient magnetic field applied together with the other of the pulses in relation to selecting a slice to which the other of the pulses is applied.
Abstract: The present disclosure is directed to a device and a magnetic resonance system for concentrating a magnetic field of radio frequency signals, and methods for concentrating a magnetic field of as radio frequency signal in an object to be imaged.
Abstract: An information processing apparatus according to an embodiment of the present disclosure includes a processing circuitry. The processing circuitry obtains a first g factor generated by using first magnetic resonance data acquired through a first parallel imaging process performed by using a plurality of reception coils and a second g factor generated by using second magnetic resonance data related to a second parallel imaging process performed by using the plurality of reception coils. The second parallel imaging process is different from the first parallel imaging process. The processing circuitry adjusts the first g factor so as to reduce a difference between the first g factor and the second g factor.
Abstract: The present invention relates to the locally resolved examination of objects by means of magnetic resonance (MR) and relates specifically to a less motion-artifact prone method for navigated multi-shot acquisition of diffusion-weighted image data using moment-nulled magnetic field gradients for diffusion encoding. The invention further relates to an apparatus for performing the method.
Abstract: A fat saturation method for a magnetic resonance imaging system having a main magnet providing a magnetic field B0 The method includes: driving a shim coil assembly with a first set of shimming currents to sufficiently alter a B0 field inhomogeneity of the magnetic field B0 within a region that includes a first imaging volume of interest such that water saturation inside the region is reduced from before the first set of shimming currents are applied; applying a fat saturation pulse to the region; identifying the first imaging volume of interest from the region; driving the shim coil assembly with a second set of shimming currents to alter the B0 field inhomogeneity of the magnetic field B0 within the first imaging volume of interest such that the B0 field inhomogeneity within the first imaging volume of interest is reduced; and obtaining magnetic resonance signals from the first imaging volume of interest.
Type:
Grant
Filed:
July 7, 2021
Date of Patent:
June 27, 2023
Inventors:
Philip J. Beatty, Chad Tyler Harris, Curtis Nathan Wiens
Abstract: A method for magnetic resonance imaging corrects non-stationary off-resonance image artifacts. A magnetic resonance imaging (MRI) apparatus performs an imaging acquisition using non-Cartesian trajectories and processes the imaging acquisitions to produce a final image. The processing includes reconstructing a complex-valued image and using a convolutional neural network (CNN) to correct for non-stationary off-resonance artifacts in the image. The CNN is preferably a residual network with multiple residual layers.
Type:
Grant
Filed:
March 9, 2018
Date of Patent:
June 20, 2023
Assignee:
The Board of Trustees of the Leland Stanford Junior University
Inventors:
David Y. Zeng, Dwight G Nishimura, Shreyas S. Vasanawala, Joseph Y. Cheng
Abstract: A method for recording a magnetic resonance image data set includes providing a magnetic resonance sequence. The magnetic resonance sequence includes at least one radio-frequency pulse and a slice-selection gradient pulse applied during or before the radio-frequency pulse, which is configured as non-constant. The method includes providing at least one correction term for compensating a magnetic field change of the slice-selection gradient pulse. The magnetic field change is ascertained via a transfer characteristic of the gradient system of the magnetic resonance system. The method also includes recording at least one magnetic resonance image data set with the magnetic resonance sequence using the correction term.
Abstract: Techniques are described for controlling a fleet of MR-scanner systems by means of a user interface. Each MR scanner system in the fleet of MR scanner systems comprises a hardware layer having a plurality of electronically controllable components and mechanical components to perform an MR measurement and capture MR-scanner raw data, a Measurement And Reconstruction System (MARS) computing unit configured to implement a measurement framework using a sequence to calculate real-time instructions and transmit these instructions to the components of the hardware layer for controlling the MR-scanner system, and a communication interface for communicating with an external device. Each MR scanner system has system attributes, which are transmitted to the external device via the communication interface.
Abstract: In a method for recording diffusion-weighted measurement data, using a MR system with diffusion weightings with two+ different b-values, diffusion directions and diffusion weightings with the associated b-values to be used for the desired recordings are loaded, a sequence of recordings of measurement data to be recorded consecutively are determined by sorting the diffusion directions and diffusion weightings to be recorded based on their associated b-value, such that the b-value of a recording of measurement data is less than the b-value of the immediately preceding recording of measurement data by no more than a predetermined threshold value, and the recordings are recorded based on the determined sequence. By arranging diffusion encodings for the desired recordings to be used consecutively, abrupt discontinuities in the b-values used chronologically are prevented, thereby eddy current effects from preceding recordings have time to abate in the case of recordings with small b-values.
Abstract: MR fingerprinting method in which an MR pulse sequence succession is output multiple times. The MR pulse sequence succession has MR pulse sequences of a same type output successively in time and differing in terms of a pulse sequence parameter that is varied according to a predefined scheme. During the first output, raw data from a region of interest (ROI) of an object is acquired in a short time interval by the raw data being acquired at a low information density. The total information density of the acquisition is increased with each repetition of the output. After the acquisition, image data from the ROI is reconstructed based on the acquired raw data. MR-parameter value datasets associated with reference image data and having MR parameter values, are determined by comparing the reconstructed image data with the reference image data. MR parameter maps are determined based on the determined MR parameter values.
Abstract: According to a first aspect of the present invention, there is provided a toner cartridge detachably mountable to a receiving device, the toner cartridge comprising a container including a accommodating portion for accommodating the toner and a discharge opening for discharging the toner from the accommodating portion into the receiving device; and an open/close member including a closing portion for closing the discharge opening and an engaging portion movable relative to the closing portion, the open/close member being rotatable relative to the container between (a) an opening position for causing the closing portion to open the discharge opening and (b) a closing position for causing the closing portion to close the discharge opening, wherein the engaging portion is movable relative to the closing portion between (c) a engaging position for engagement with the receiving device to receive a force for moving the open/close member from the opening position to the closing position when the toner cartridge is d
Abstract: Techniques are disclosed for capturing scan data of an examination object via a magnetic resonance system. The techniques include capturing a first set of a diffusion-weighted scan data by excitation and, in an acquisition phase, acquiring a first echo signal, wherein before the acquisition phase in a diffusion preparation phase, diffusion gradients are switched for diffusion encoding of the scan data, The techniques additionally include capturing a second set of non-diffusion-weighted scan data by excitation and, in an acquisition phase, acquiring a second echo signal, wherein before the acquisition phase, in a diffusion preparation phase, the same diffusion gradients are switched as are switched for diffusion encoding of the scan data of the first set of diffusion-weighted scan data, although they have no influence on the second echo signal. Diffusion-weighted and non-diffusion-weighted scan data is thereby captured, having identical disturbances caused by eddy currents induced by switched gradients.
Abstract: In a method for correcting influences on magnetic resonance imaging of an examination object caused by fluctuations in a basic magnetic field, an MR data set is generated for two or more measurement periods, and a regression analysis is performed. Each of the MR data sets may contain at least one two-dimensional individual data set. The regression analysis may determine at least one phase correction value for a measurement period to be corrected. Two or more different individual data sets may be taken into account in the analysis. An MR image may generated based on the MR data sets and the at least one phase correction value.
Abstract: The present invention provides a method for compensation of periodic B0 modulations from a periodic motion of a cold head (212) of a main magnet (114) of a magnetic resonance (MR) imaging system (110), whereby main windings (200) of the main magnet (114) are cooled to superconductivity by the cold head (212), which exerts a repetitive motion, the method comprising the steps of measuring a periodic occurrence of spatial field components of the B-field based on a motion of the cold head (212) as a function of time, performing a sensor measurement of a periodic, auxiliary parameter of the MR imaging system (110), which is not the periodic occurrence of spatial field components, synchronizing the periodic occurrence of spatial field components of the B-field with the measured periodic, auxiliary parameter of the MR imaging system (110), and triggering based on the measured periodic sensor measurement of the MR imaging system (110) a periodic application of compensation signals to compensate the periodic occurrenc
Type:
Grant
Filed:
January 12, 2018
Date of Patent:
May 9, 2023
Assignee:
Koninklijke Philips N.V.
Inventors:
Cornelis Leonardus Gerardus Ham, Filips Van Liere
Abstract: A magnetic resonance imaging apparatus according to an embodiment includes sequence control circuitry and processing circuitry. The sequence control circuitry performs multi-frame acquisition where FOVs (Field Of Views) of at least two acquired frames are overlapped in a first direction. Then, based on the multi-frame acquisition performed by the sequence control unit, the processing unit generates data regarding the components in the first direction of flow of a fluid.
Abstract: Medical imaging analysis systems are configured to perform automatic image registration algorithms that perform three-dimensional (3D), affine, and/or intensity-based co-registration of magnetic resonance imaging (MRI) data, such as multiparametric MRI (mpMRT) data, using mutual information (MI) as a similarity metric. An apparatus comprises a computer-readable storage medium storing a plurality of imaging series of magnetic resonance imaging (MRI) data for imaged tissue of a patient; and a processor coupled to the computer-readable storage medium. The processor is configured to receive the imaging series of MRI data; identify a volume of interest (VOI) of each image of the imaging series of MRI data; compute registration parameters for the VOIs through the maximization of mutual information of the corrected VOIs; and register the VOIs using the computed registration parameters.
Type:
Grant
Filed:
January 3, 2020
Date of Patent:
April 25, 2023
Assignee:
Regents of the University of Minnesota
Inventors:
Ethan Yize Leng, David Henry Porter, Gregory John Metzger
Abstract: In a method for acquiring measurement data using a magnetic resonance (MR) system having a gradient unit, frequency-dependent parameters characterizing the gradient unit of the MR system are accessed (e.g. loaded from a memory), a k-space trajectory of a RESOLVE (Readout Segmentation Of Long Variable Echo trains) sequence planned for a MR measurement is accessed, MR measurement data is acquired based on the planned k-space trajectory and reconstructing image data from the MR measurement data, and an electronic signal is provided that represents the reconstructed image data as an output of the MR system. The k-space trajectory may have a frequency component in at least one direction. The planned k-space trajectory may be corrected based on at least one frequency component of the planned k-space trajectory and the frequency-dependent parameters.
Abstract: The present disclosure relates to an un-motorized coiling mechanism for cable handling in medical scanning. A medical scanner accessory system for a medical scanner is disclosed.
Abstract: According to a first aspect of the present invention, there is provided a toner cartridge detachably mountable to a receiving device, the toner cartridge comprising a container including a accommodating portion for accommodating the toner and a discharge opening for discharging the toner from the accommodating portion into the receiving device; and an open/close member including a closing portion for closing the discharge opening and an engaging portion movable relative to the closing portion, the open/close member being rotatable relative to the container between (a) an opening position for causing the closing portion to open the discharge opening and (b) a closing position for causing the closing portion to close the discharge opening, wherein the engaging portion is movable relative to the closing portion between (c) a engaging position for engagement with the receiving device to receive a force for moving the open/close member from the opening position to the closing position when the toner cartridge is d