G01R33/56341

MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD, AND COMPUTER-READABLE STORAGE MEDIUM
20230168325 · 2023-06-01 ·

A magnetic resonance imaging system and method, and a computer-readable storage medium are provided. The magnetic resonance imaging method includes: acquiring a plurality of k-space data sets by using a plurality of imaging sequences, each imaging sequence comprising a pre-phase-dispersion gradient pulse and a plurality of phase encoding gradients applied after the pre-phase-dispersion gradient pulse, wherein the pre-phase-dispersion gradient pulses of the plurality of imaging sequences have a standard area difference therebetween when ordered according to area values; respectively reconstructing magnetic resonance images from the respective k-space data sets; and averaging amplitudes of the magnetic resonance images to generate a magnetic resonance image of an average amplitude.

EPI MR IMAGING WITH DISTORTION CORRECTION
20220057467 · 2022-02-24 ·

The invention relates to a method of MR imaging of an object (10) positioned in an examination volume of a MR device (1). An object of the invention is to provide a method that enables EPI imaging with improved distortion correction. The method of the invention comprises the steps of: acquiring reference MR signal data from the object (10) using a multi-point Dixon method; deriving a B.sub.0 map from the reference MR signal data; acquiring a series of imaging MR signal data sets from the object (10), wherein an instance of an echo planar imaging sequence is used for acquisition of each imaging MR signal data set; and reconstructing an MR image from each imaging MR signal data set, wherein geometric distortions in each MR image are corrected using the B.sub.0 map. Moreover, the invention relates to a MR device (1) for carrying out the method, and to a computer program to be run on a MR device (1).

MUTLI-SHOT MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD
20170307707 · 2017-10-26 ·

The present invention provides a magnetic resonance imaging system for imaging a subject by a multi-shot imaging. The magnetic resonance imaging system comprises an acquiring unit for acquiring MR raw data corresponding to a plurality of shots; an imaging unit for generating a plurality of folded images from the MR raw data, wherein each of the plurality of folded images is generated from a subset of the MR raw data; a deriving unit for deriving magnitude of each pixel of each folded image; a detecting unit for detecting a motion of the subject during the multi-shot imaging based on similarity measurements of any two folded images of the plurality of folded images, wherein the detecting unit further comprises a first deriving unit configured to derive the measured similarities; and a reconstructing unit for reconstructing a MR image of the subject based on MR raw data obtained according to a detection result of the detecting unit. Since the partially acquired MR raw data is used for motion detection directly, it would be more rapid and stable.

Mutli-shot magnetic resonance imaging system and method
11255938 · 2022-02-22 · ·

The present invention provides a magnetic resonance imaging system for imaging a subject by a multi-shot imaging. The magnetic resonance imaging system comprises an acquiring unit for acquiring MR raw data corresponding to a plurality of shots; an imaging unit for generating a plurality of folded images from the MR raw data, wherein each of the plurality of folded images is generated from a subset of the MR raw data; a deriving unit for deriving magnitude of each pixel of each folded image; a detecting unit for detecting a motion of the subject during the multi-shot imaging based on similarity measurements of any two folded images of the plurality of folded images, wherein the detecting unit further comprises a first deriving unit configured to derive the measured similarities; and a reconstructing unit for reconstructing a MR image of the subject based on MR raw data obtained according to a detection result of the detecting unit. Since the partially acquired MR raw data is used for motion detection directly, it would be more rapid and stable.

Method to select radiation dosage for tumor treatment based on cellular imaging

Methods, systems, and apparatuses are disclosed for radiation treatment of tumors based at least in part on patient-specific imaging information. The methods, systems and apparatuses include computer programs encoded on computer-readable media. The methods include acquiring imaging information relating to a target to be treated. The imaging information is non-anatomic imaging information relating to the target acquired from at least one imaging marker that reflects at least one of the metabolic, physiological and histological features of the target. The methods further include computing a radiation dose based at least on the imaging information.

Method and system for creating magnetic resonance images
11255940 · 2022-02-22 · ·

In a method and system, a reference dataset is recorded using a reference scan based on a GRE or RA RT sequence. A correction dataset is also recorded using a phase correction scan based on a non-phase-encoding EPI sequence. A measurement dataset is recorded using an SMS sequence. Slice-specific GRAPPA kernels are determined from the reference dataset and magnetic resonance images are created by a slice GRAPPA method. Data of the measurement dataset belonging to different slices is separated from one another using the slice-specific GRAPPA kernels and N/2 ghost artifacts are corrected using the correction dataset.

Pulse sequence method for MRI

The present invention describes a method for magnetic resonance (MR) and/or MR imaging, comprising acquisition of signals and MR images originating from a RF and gradient sequence causing isotropic diffusion weighting of signal attenuation, wherein the isotropic diffusion weighting is achieved by one time-dependent dephasing vector q(t) having an orientation, wherein the isotropic diffusion weighting is proportional to the trace of a diffusion tensor D, and wherein the orientation of the time-dependent dephasing vector q(t) is either varied discretely in more than three directions in total, or changed continuously, or changed in a combination of discretely and continuously during the gradient pulse sequence, 0≦t≦echo time, where t represents the time. The method may be performed during a single shot (single MR excitation).

Method for ascertaining a deviation of at least one gradient field from a reference

The disclosure relates to a method for ascertaining a deviation of at least one gradient field of a magnetic resonance system from a reference. The method includes providing at least one first image data set and one second image data set of a phantom with isotropic diffusion properties, recorded with a diffusion-weighted imaging sequence, wherein the first image data set and the second image data set are recorded with different diffusion-weightings along a gradient direction to be tested of the gradient field using the magnetic resonance system. The method further includes ascertaining a map of apparent diffusion coefficients from the image data sets for at least a portion of the image points of the image data sets. The method further includes comparing the apparent diffusion coefficients with the reference.

EDEMA INVARIANT TRACTOGRAPHY

Edema invariant tractography methods are provided. The methods include acquiring data using a multishell, high angular resolution diffusion imaging sequence; (ii) modeling the data using a multi-compartment model; and (iii) reconstructing the fibers through a probabilistic tracking algorithm using a fiber orientation distribution which has streamlines fitted to the output of said probabilistic tracking algorithm.

MAGNETIC RESONANCE IMAGING DEVICE
20170281041 · 2017-10-05 ·

There is provided a technique for DWI measurement, in which MPG application is performed in many directions, that enables detection of presence or absence of body motion during imaging without prolongation of imaging time. A plurality of image groups each comprising 6 or more diffusion-weighted images selected from a plurality of diffusion-weighted images are created so the groups differ from one anther in one or more diffusion-weighted images included in each of the groups. Value of a predetermined diffusion index representing a characteristic amount of diffusion-weighted image is calculated for each image group from the diffusion-weighted images included in each image group. Value of a predetermined body motion index relating to body motion information is calculated from the value of the diffusion index for each image group. Presence or absence of body motion is determined for each image group on the basis of the value of the body motion index.