Patent classifications
G01R33/4826
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.
QUIET MRI USING ALTERNATING GRADIENT SEQUENCE
Magnetic resonance imaging (MRI) systems and methods to effect MRI data acquisition with reduced noise are described. A readout gradient, having a first polarity used to acquire and store MRI data in k-space memory during analog-to-digital conversion (ADC) of MR RF signals during one TR interval, is continued at substantially a same amplitude and vector direction and used as an image volume selection gradient during a transmitted RF excitation pulse that begins a next TR interval before the readout gradient transitions to an opposite polarity. The acquired k-space data is then used to generate an MR image.
QUIET MRI WITH SPIN ECHO (SE) OR FAST SPIN ECHO (FSE)
Magnetic resonance imaging (MRI) systems and methods to effect MRI data acquisition with reduced noise in fast spin echo (FSE) and spin echo (SE) implementations are described. The improved MRI data acquisition is performed by acquiring k-space data while maintaining a constant or near constant slice select gradient amplitude throughout a sequence kernel. The acquired k-space data can then be used to generate an MR image.
Deep learning method for nonstationary image artifact correction
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.
Reduced Field-of-View Perfusion Imaging With High Spatiotemporal Resolution
Some aspects of the present disclosure relate a method for magnetic resonance imaging, which can include acquiring, by applying an imaging pulse sequence, magnetic resonance data associated with a region of interest of a subject. The imaging pulse sequence can include a plurality of RF pulses configured to generate a desired image contrast, and an outer-volume suppression (OVS) module to attenuate the signal outside the region of interest. The method can further include reconstructing, from the acquired magnetic resonance data, a plurality of reduced field of view (rFOV) magnetic resonance images corresponding to the region of interest.
APPARATUS AND METHOD FOR GENERATING VOLUME SELECTIVE THREE-DIMENSIONAL MAGNETIC RESONANCE IMAGE
An apparatus and a method for generating a volume-selective three-dimensional magnetic resonance image are disclosed. The volume-selective three-dimensional magnetic resonance image generating method according to an exemplary embodiment of the present disclosure includes applying a frequency selective excitation pulse and a slab selection gradient magnetic field together to an object; acquiring a signal generated from the object by the excitation pulse and the slab selection gradient magnetic field; and generating a three-dimensional magnetic resonance image through encoding based on a readout gradient magnetic field maintaining vertically to the acquired signal and the slab selection gradient magnetic field.
Respiratory Phase-resolved 3D Body Imaging Using Iterative Motion Correction and Average
A method for performing 3D body imaging includes performing a 3D MRI acquisition of a patient to acquire k-space data and dividing the k-space data into k-space data bins. Each bin includes a portion of the k-space data corresponding to a distinct breathing phase. 3D image sets are reconstructed from the bins, with each 3D image set corresponding to a distinct k-space data bin. For each bin other than a selected reference bin, forward and inverse transforms are calculated between the 3D image set corresponding to the bin and the 3D image set corresponding to the reference bin. Then, a motion corrected and averaged image is generated for each bin by (a) aligning the 3D image set from each other bin to the 3D image set corresponding to the bin using the transforms, and (b) averaging the aligned 3D image sets to yield the motion corrected and averaged image.
3D UTE IMAGING USING VARIABLE-TE STACK-OF-SPIRALS ACQUISITION
Some aspects of the present disclosure relate to ultrashort-echo-time (UTE) imaging. In one embodiment, a method includes acquiring UTE imaging data associated with an area of interest of a subject. The acquiring comprises applying an imaging pulse sequence with a three-dimensional (3D) spiral acquisition and a nonselective excitation pulse. The method also includes reconstructing at least one image of the area of interest from the acquired UTE imaging data.
SILENT MULTI-GRADIENT ECHO MAGNETIC RESONANCE IMAGING
Methods and systems for production of silent, multi-gradient-echo, magnetic resonance images are provided. The methods employ iterative application of small updates to the magnetic field gradient followed by a short, non-selective radiofrequency pulse excitation and for free induction decay data acquisition. The magnetic field gradient updates allow for silent, self-refocusing pulse sequence. Subsequent applications of the magnetic field gradients allow for multiple echo data acquisitions, which may allow fast, silent production of T2*-weighted images.
Method and Apparatus for Improved Efficiency of Non-Cartesian Imaging Using Accelerated Calibration Scan for K-Space Shift Correction
A system and method for performing accelerated k-space shift correction calibration scans for non-Cartesian trajectories is provided. The method can include applying an MRI sequence, performing a calibration scan based on the MRI sequence using the non-Cartesian trajectory to acquire k-space shift data, wherein one or more partitions are skipped during the calibration scan, interpolating the skipped one or more partitions using the k-space shift data from adjacent partitions, and calibrating the MRI system using the k-space shift data and the interpolated k-space shift data. In some embodiments, an acceleration factor Acc can be defined and the calibration scan acquires k-space shift data for only one partition in every Acc partitions.