Patent classifications
G01R33/56518
Method for Reducing Artifacts in Image Data Sets Acquired Using Magnetic Resonance
A method for reconstructing single-slice image data sets from k-space measured data sets that have been acquired simultaneously from at least two slices from an examination object. The method includes an iterative modification and hence an optimization of the underlying k-space trajectories in the reconstruction of individual image data sets from collapsed measured data sets acquired from a plurality of slices and hence a retrospective reduction of interference in the individual image data sets that are obtained.
AUTOMATED DEEP CORRECTION OF MRI PHASE-ERROR
A method and system for automated correction of phase error in MRI-based flow evaluation employs a computer processor programmed to execute a trained convolutional neural network (CNN) to receive and process image data comprising flow velocity data in three directions and magnitude data collected from a region of interest over a scan period from magnetic resonance imaging instrumentation. The image data is processed using the trained CNN to generate three output channels with pixelwise inferred corrections for the flow velocity data which are further smoothed using a regression algorithm. The smoothed corrections are added to the original image data to generate corrected flow data, which may be used for flow visualization and quantization.
Ferromagnetic frame for magnetic resonance imaging
An apparatus for providing a B.sub.0 magnetic field for a magnetic resonance imaging system. The apparatus includes at least one permanent B.sub.0 magnet to contribute a magnetic field to the B.sub.0 magnetic field for the MRI system and a ferromagnetic frame configured to capture and direct at least some of the magnetic field generated by the B.sub.0 magnet. The ferromagnetic frame includes a first post having a first end and a second end, a first multi-pronged member coupled to the first end, and a second multi-pronged member coupled to the second end, wherein the first and second multi-pronged members support the at least one permanent B.sub.0 magnet.
Gradient coil unit for a magnetic resonance device including an eddy current compensating conductor structure
The disclosure relates to a gradient coil unit comprising at least one first conductor structure, which is configured to generate a magnetic field gradient in a first direction, and an eddy current compensating conductor structure, which is configured to compensate for a first magnetic field. The first magnetic field is generated by a current induced in the first conductor structure as a result of activation of a conductor structure comprised by the gradient coil unit.
System and method to reduce eddy current artifacts in magnetic resonance imaging
Some implementations provide a system that includes: a housing having a bore in which a subject to be image is placed; a main magnet configured to generate a volume of magnetic field within the bore, the volume of magnetic field having inhomogeneity below a defined threshold; one or more gradient coils configured to linearly vary the volume of magnetic field as a function of spatial location; one or more pulse generating coils configured to generate and apply radio frequency (RF) pulses to the volume of magnetic field in sequence to scan the portion of the subject; one or more shim gradient coils configured to perturb a spatial distribution of the linearly varying volume of magnetic field; and a control unit configured to operate the gradient coils, pulse generating coils, and shim gradient coils such that only the user-defined region within the volume of magnetic field is imaged.
NOISE SUPPRESSION METHODS AND APPARATUS
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.
Sheath wave barrier for magnetic resonance (MR) applications
A sheath wave barrier (2) for suppressing electromagnetic RF coupling phenomena of an electrical cable (4) at a predetermined suppression frequency (coo) in a magnetic resonance (MR) imaging or spectroscopy apparatus, wherein the cable is configured as a shielded cable with at least one inner conductor (6) and a peripherally surrounding electrically conducting cable sheath (8), comprises a segment of said shielded cable and a primary inductor formed from said shielded cable segment between a first cable location (12) and a second cable location (14). A secondary inductor (16) formed by a conductor is concentrically arranged within or around the primary inductor between said first and second cable locations. The secondary inductor is electrically connected to the cable sheath at said first and second cable connections over respective first and second RLC network members (M1, M2), the primary and secondary inductors being configured in compensating manner such that magnetic field generated by said primary and secondary inductors is substantially cancelled in any region surrounding the sheath wave barrier.
Method for measuring eddy current fields in a magnetic resonance device, magnetic resonance device, computer program and electronically readable data carrier
Systems and methods for measuring eddy current fields occurring as a result of gradient pulses in a magnetic resonance sequence at a point in time during the magnetic resonance sequence in relation to at least one direction of pulse effect. At least the parts of the magnetic resonance sequence comprising the gradient pulses relating to the at least one direction of pulse effect are performed as a preparation sequence up until the point in time followed directly by a measurement sequence in which first measurement data is recorded. The preparation sequence is played out again with the same, directly consecutive measurement sequence without the gradient pulses relating to the at least one direction of pulse effect or with gradient pulses having an inverted sign relating to the at least one direction of pulse effect. Second measurement data is recorded. Using a joint evaluation of the first and second measurement data at least one variable characterizing the eddy current field generated by the eddy currents of the gradient pulses in the at least one direction of pulse effect is determined.
METHOD FOR RECORDING DIFFUSION-WEIGHTED MEASUREMENT DATA BY MEANS OF A MAGNETIC RESONANCE SYSTEM
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.
METHOD FOR CREATING DIFFUSION-WEIGHTED AND NON-DIFFUSION-WEIGHTED SCAN DATA BY MEANS OF MAGNETIC RESONANCE
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.