G01R33/5618

IMAGING SYSTEMS AND METHODS
20210259568 · 2021-08-26 · ·

An imaging method may include obtaining imaging data associated with a region of interest (ROI) of an object. The imaging data may correspond to a plurality of time-series images of the ROI. The imaging method may also include determining, based on the imaging data, a data set including a spatial basis and one or more temporal bases. The spatial basis may include spatial information of the imaging data. The one or more temporal bases may include temporal information of the imaging data. The imaging method may also include storing, in a storage medium, the spatial basis and the one or more temporal bases.

Method and magnetic resonance apparatus for generating a combination image dataset
11016162 · 2021-05-25 · ·

In a method and magnetic resonance apparatus for generating at least one combination image dataset, a first image dataset is acquired with a turbo spin echo sequence, wherein the echo signals are timed so that the spins of two spin species in the region to be examined are in-phase. A second image dataset is acquired with a turbo spin echo sequence, wherein the echo signals are timed so that the spins of two spin species in the region to be examined have opposed phase. The first image dataset and the second image dataset are combined to form a combination image.

Method for echo planar time-resolved magnetic resonance imaging

Systems and methods for magnetic resonance imaging (“MRI”) that address the geometric distortions and blurring common to conventional echo planar imaging (“EPI”) sequences, and that provide new temporal signal evolution information across the EPI readout, are described. Echo planar time-resolved imaging (“EPTI”) schemes are described to implement an accelerated sampling of a hybrid space spanned by the phase encoding dimension and the temporal dimension. In general, each EPTI shot covers a segment of this hybrid space using a zigzag trajectory with an interleaved acceleration in the phase-encoding direction. The hybrid space may be undersampled and a tilted reconstruction kernel used to synthesize additional data samples.

MR IMAGING USING A STACK-OF-STARS ACQUISITION WITH INTRINSIC MOTION CORRECTION

The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging using the stack-of-stars or stack-of-spirals acquisition scheme providing an enhanced image quality in the presence of motion. The method of the invention comprises the steps of:—generating MR signals by subjecting the object to an imaging sequence comprising RF pulses and switched magnetic field gradients;—acquiring signal data according to a stack-of-stars or stack-of-spirals scheme, wherein the MR signals are acquired as radial or spiral k-space profiles from a number of parallel slices arranged at adjacent positions along a slice direction, wherein a central portion (20) of k-space is more densely sampled during the acquisition than peripheral portions (21) of k-space;—reconstructing an intermediate MR image (22-25) from sub-sampled signal data for each of a number of successive time intervals;—deriving motion induced displacements and/or deformations by registering the intermediate MR images (22-25) with each other; and—combining the sub-sampled signal data and reconstructing a final MR image therefrom, wherein a motion correction is applied according to the derived motion induced displacements and/or deformations. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

METHOD AND SYSTEM FOR SIMULTANEOUS QUANTITATIVE MULTIPARAMETRIC MAGNETIC RESONANCE IMAGING (MRI)
20210134028 · 2021-05-06 · ·

A method and system for simultaneous quantitative multiparametric MRI are provided in the disclosure. The method includes: designing a magnetic resonance imaging (MRI) sequence which includes a signal excitation part, a shift gradient part, and a data acquisition part; generating training samples for a deep neural network according to the MRI sequence; training the deep neural network by using the training samples, to obtain a trained deep neural network; and reconstructing multiple magnetic-resonance parametric maps by using the trained deep neural network and k-space data acquired by the MRI sequence. The disclosure can implement quantitative multiparametric MRI, and can correct image distortions caused by magnetic field inhomogeneity.

SYSTEM AND METHOD FOR MAGNETIC RESONANCE IMAGING
20210118203 · 2021-04-22 · ·

A system for MRI is provided. The system may obtain a plurality of sets of under-sampled k-space data corresponding to a plurality of frames. Each set of under-sampled k-space data may be acquired simultaneously from a plurality of slice locations of a subject in one of the frames using an MRI scanner. The system may reconstruct a plurality of reference slice images based on the sets of under-sampled k-space data of the plurality of frames. Each of the reference slice images may be representative of one of the slice locations in more than one frame of the frames. The system may further reconstruct a plurality of image series based on the sets of under-sampled k-space data and the reference slice images. Each image series may correspond to one of the slice locations and include a plurality of slice images of the corresponding slice location in the plurality of frames.

MAGNETIC RESONANCE DIXON METHOD
20210080530 · 2021-03-18 · ·

Techniques are disclosed for acquiring at least two measurement datasets, each consisting of measurement data. The two measurement datasets are recorded at points in time at which spins of a first spin species present in the examination object have different phase positions from spins of a second spin species present in the examination object. Moreover, the two measurement datasets are recorded in each case while switching readout gradients of different polarity, and thus the desired measurement datasets may be recorded faster than conventional approaches.

Systems and methods for low-field fast spin echo imaging

A magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.

METHOD FOR MAGNETIC RESONANCE IMAGING AND MAGNETIC RESONANCE DEVICE
20210215780 · 2021-07-15 · ·

In a method for MRI where k-space describing spatial frequencies in an acquisition volume (AV) is scanned, a first measured data acquisition is performed in the AV with a first gradient field strength of a gradient field, including irradiating a RF pulse into the AV and acquiring a first series of measured values spaced apart temporally, a second measured data acquisition is performed with a second, different gradient field strength, including irradiating a RF pulse into the AV and acquiring a second series of measured values spaced apart temporally. With the first measured data acquisition, the first measured values for a respective response signal are acquired at a first time interval from one another and with the second measured data acquisition, the second measured values for a respective response signal are acquired at a second, different time interval from one another.

Simultaneous pH and oxygen weighted MRI contrast using multi-echo chemical exchange saturation transfer imaging (ME-CEST)

The present disclosure provides a method that includes applying at least one radiofrequency saturation pulse at a frequency or a range of frequencies to substantially saturate magnetization corresponding to an exchangeable proton in the ROI to generate magnetic resonance (MR) data. The MR data is then acquired using an echo-planar imaging readout, which is configured to sample a series of gradient echo pulse trains at a series of gradient echo times and a series of spin echo pulse trains at a series of spin echo times. One or more relaxometry measurement is then computed using the MR data sampled at the gradient echo times and the spin echo times. An oxygen-weighted image is then generated using the one or more relaxometry measurement, and a pH-weighted image is generated using MR data sampled at one or more of the spin echo times or gradient echo times.