Patent classifications
G01R33/561
Artefact reduction in magnetic resonance imaging
Techniques for compensating magnetic resonance imaging (MRI) data for artefacts caused by motion of a subject being imaged. The techniques include obtaining spatial frequency data obtained by using a magnetic resonance imaging (MRI) system to perform MRI on a patient, the spatial frequency data including first spatial frequency data and second spatial frequency data; determining a transformation using a first image obtained using the first spatial frequency data and a second image obtained using the second spatial frequency data; determining a residual spatial phase; correcting, using the transformation, second spatial frequency data and the residual spatial phase, to obtain corrected second spatial frequency data and a corrected residual spatial phase; and generating a magnetic resonance (MR) image using the corrected second spatial frequency data and the corrected residual spatial phase.
Single-shot pseudo-centric epi method for magnetization-prepared imaging
Provided is a method for generating MRI data including applying, by an MRI computing device, an RF excitation pulse, and completing, by the MRI computing device, a K-space by acquiring a plurality of phase encoding line groups, in a state in which any other RF excitation pulse is not applied after applying the RF excitation pulse, in which each of the plurality of phase encoding line groups includes a plurality of phase encoding lines, and an absolute value of an average phase encoding size of a phase encoding line group acquired earlier is not greater than an absolute value of an average phase encoding size of a phase encoding line group acquired later, among the plurality of phase encoding line groups.
PATIENT COUCH WITH FLEXIBLE RF TRANSMITTING POWER DISTRIBUTION FOR A MAGNETIC RESONANCE TOMOGRAPHY SYSTEM
A patient couch for a magnetic resonance tomography system and a magnetic resonance tomography system are provided. The patient couch includes a feed facility for radiofrequency energy having a plurality of conduction paths for feeding radiofrequency energy. The patient couch also includes a plurality of plug-in connectors for local coils having a transmit coil, and a distribution structure for the distribution of radiofrequency energy from the feed facility to the plug-in connectors.
PATIENT COUCH WITH FLEXIBLE RF TRANSMITTING POWER DISTRIBUTION FOR A MAGNETIC RESONANCE TOMOGRAPHY SYSTEM
A patient couch for a magnetic resonance tomography system and a magnetic resonance tomography system are provided. The patient couch includes a feed facility for radiofrequency energy having a plurality of conduction paths for feeding radiofrequency energy. The patient couch also includes a plurality of plug-in connectors for local coils having a transmit coil, and a distribution structure for the distribution of radiofrequency energy from the feed facility to the plug-in connectors.
REDUCTION OF EDDY CURRENTS DURING FLOW ENCODED MAGNETIC RESONANCE IMAGING
In a method and magnetic resonance (MR) apparatus for establishing imaging sequence parameter values with a reduced eddy current formation for flow-encoded magnetic resonance imaging, a number of different flow-encoded candidate raw datasets are acquired by executing a flow-encoded gradient measurement sequence with different imaging sequence parameter values from a test or calibration region of an examination object. Flow-encoded candidate image datasets are reconstructed from the different flow-encoded candidate raw datasets. A flow-encoded candidate image dataset is selected as a function of a background phase contrast established in a phase-contrast image assigned to the respective flow-encoded candidate image dataset. The imaging sequence parameter values assigned to the flow-encoded candidate image dataset are selected as parameter values for an imaging sequence for subsequent diagnostic flow-encoded magnetic resonance imaging.
Determining calibration data for a reconstruction of image data from scan data acquired by means of a magnetic resonance system
Calibration data is determined for a reconstruction of image data from scan data acquired via a magnetic resonance system. This includes specifying acquisition shots for an acquisition of desired scan data in which acquisition shots scan data is acquired after radiating-in an RF excitation pulse, identifying first acquisition shots among the acquisition shots specified in which scan data is acquired in a central region in k-space, stipulating a sequence in which the specified acquisition shots are to be carried out such that first acquisition shots are arranged in the sequence in a starting portion to be carried out first, acquiring the scan data by carrying out the specified acquisition shots in the stipulated sequence, determining calibration data from scan data acquired in the starting portion of the sequence, and reconstructing image data using the acquired scan data and the specified calibration data.
System and Methods for Ultra-Fast Multi-Dimensional Diffusion-Relaxation MRI Using Time-Division Multiplexing Sequences
Scan time in diffusion-relaxation magnetic resonance imaging (“MRI”) is reduced by implementing time-division multiplexing (TDM). In general, time-shifted radio frequency (“RF”) pulses are used to excite two or more imaging volumes. These RF pulses are applied to induce separate echoes for each slice. Diffusion MRI data can thus be acquired with different echo times, or alternatively with the same echo time, in significantly reduced overall scan time. Multidimensional correlations between diffusion and relaxation parameters can be estimated from the resulting data.
ECHO-SPACING SHUFFLING FOR ECHO-PLANAR-IMAGING
The disclosure is directed to an Echo-Planar-Imaging (EPI) magnetic resonance imaging techniques combined with a variable-density undersampling scheme. The technique comprises generating an RF pulse, applying a switched frequency-encoding read out gradient in a variable time interval, and applying simultaneously an intermittently blipped low-magnitude phase-encoding gradient with a variable value of an integral of the phase-encoding gradient. The aforementioned steps are carried out such that the k-space is at least partially undersampled and the time interval of one read out gradient is varied depending on the integral of the phase encoding gradient, such that a ratio between the variable time interval of the read out gradient and the integral of the corresponding phase encoding gradient is kept above or at a predetermined constant value, which is related to a predetermined criteria of image quality.
Artefact reduction in magnetic resonance imaging
Techniques of prospectively compensating for motion of a subject being imaged by an MRI system, the MRI system comprising a plurality of magnetics components including at least one gradient coil and at least one radio-frequency (RF) coil, the techniques comprising: obtaining first spatial frequency data and second spatial frequency data by operating the MRI system in accordance with a pulse sequence, wherein the pulse sequence is associated with a sampling path that includes at least two non-contiguous portions each for sampling a central region of k-space; determining a transformation using a first image obtained using the first spatial frequency data and a second image obtained using the second spatial frequency data; correcting the pulse sequence using the determined transformation to obtain a corrected pulse sequence; and obtaining additional spatial frequency data in accordance with the corrected pulse sequence.
Systems and methods for magnetic resonance imaging
A method for magnetic resonance imaging (MRI) is provided. The method may include obtaining scan data of a subject. The scan data may be acquired by an MR scanner at a time according to a pulse sequence. The method may include obtaining motion data of the subject. The motion data of the subject may be acquired by one or more sensors at the time. The motion data may reflect a motion state of the subject at the time. The method may also include determining, based on the motion data of the subject, a processing strategy indicating whether using the scan data to fill one or more k-space lines corresponding to the pulse sequence in a k-space. The method may further include obtaining k-space data based on the processing strategy.