G01R33/56545

MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD
20170089993 · 2017-03-30 · ·

A method of magnetic resonance imaging includes executing an imaging sequence, in response to the imaging sequence, acquiring magnetic resonance data, entering the acquired magnetic resonance data in k-space in a memory along a predetermined k-space trajectory, and modifying the k-space trajectory during acquisition of the magnetic resonance data.

MRI WITH RECONSTRUCTION OF MR PHASE IMAGE
20170059682 · 2017-03-02 ·

A method for magnetic resonance (MR) phase imaging of a subject includes: (i) for each channel of a multi-channel MRI scanner, acquiring MR measurements at a plurality of voxels of the subject using a pulse sequence that reduces MR measurement phase error; and (ii) for each voxel, determining reconstructed MR phase from the MR measurements of each channel to form an MR phase image of the subject. The step of determining reconstructed MR phase may be performed for each of the voxels independently.

Systems and methods of deep learning for large-scale dynamic magnetic resonance image reconstruction

A method for performing magnetic resonance imaging on a subject comprises obtaining undersampled imaging data, extracting one or more temporal basis functions from the imaging data, extracting one or more preliminary spatial weighting functions from the imaging data, inputting the one or more preliminary spatial weighting functions into a neural network to produce one or more final spatial weighting functions, and multiplying the one or more final spatial weighting functions by the one or more temporal basis functions to generate an image sequence. Each of the temporal basis functions corresponds to at least one time-varying dimension of the subject. Each of the preliminary spatial weighting functions corresponds to a spatially-varying dimension of the subject. Each of the final spatial weighting functions is an artifact-free estimation of the one of the one or more preliminary spatial weighting functions.

Magnetic resonance imaging with prior knowledge and oversampling

The invention provides a method for performing magnetic resonance imaging, MRI, which exploits prior knowledge of the interactions between electromagnetic fields and spins in the sampled object. This technique is able to provide shorter acquisition times with respect to traditional (Nyquist-Shannon limited) MRI. The method is based on an encoding matrix formalism constructed from the specific knowledge of how every spin would evolve in time depending on their position for a given pulse sequence. This particular previous knowledge has not been fully exploited previously by traditional MRI techniques. Moreover, the method of the invention can be used in combination with other schemes, such as compressed sensing, parallel imaging, or deep learning, for further shortening the MRI scan time.

Comprehensive Cardiovascular Analysis with Volumetric Phase-Contrast MRI
20170045600 · 2017-02-16 ·

Processing techniques of volumetric anatomic and vector field data from volumetric phase-contrast MRI on a magnetic resonance imaging (MRI) system are provided to evaluate the physiology of the heart and vessels. This method includes the steps of: (1) correcting for phase-error in the source data, (2) visualizing the vector field superimposed on the anatomic data, (3) using this visualization to select and view planes in the volume, and (4) using these planes to delineate the boundaries of the heart and vessels so that measurements of the heart and vessels can be accurately obtained.

MAGNETIC RESONANCE IMAGING APPARATUS AND IMAGE PROCESSING METHOD

Provided is a technology capable of effectively obtaining a ringing correction effect even for a two-dimensional image or a three-dimensional image with a simple CNN configuration.

A CNN that has been trained to perform ringing correction for a direction of a dimension lower than a dimension of an image that is a correction target is prepared, and the CNN is applied in multiple stages to perform the ringing correction. For training the CNN, an image captured by increasing a measurement matrix size in one or two directions need only be used, thereby reducing an imaging time for acquiring training data and a burden of data processing, and enabling handling of images of various dimensions.

MAGNETIC RESONANCE IMAGING APPARATUS AND IMAGE PROCESSING METHOD

Provided is a technology capable of reducing a load during a training process and an application process of a CNN, and performing effective ringing correction in accordance with a sampling pattern.

An aspect of the present invention provides an MRI apparatus including, as a ringing correction unit, a CNN for each sampling pattern. The CNN is trained by using a correct answer image in which rectangular or rectangular parallelepiped ringing in has not occurred and a plurality of processed pattern images. In the application of the CNN, measurement data is reconstructed at a desired reconstruction matrix size by performing zero-filling on the measurement data, and then a CNN corresponding to the sampling pattern of the measurement data is selected and applied to perform the ringing correction in a real space.

Magnetic resonance method and tomography system for acquiring image data sets

In a method and a magnetic resonance tomography system, at least two temporally separate original data sets are acquired with one phase measurement value being acquired for each pixel in each original image data set. An optimization technique for the shared calculation of corrected phase values for the pixels in the data sets is implemented in a computer, wherein the corrected phase values of the pixels in a first of the data sets is in each case dependent at least on the phase measured value of the pixel at the same location in a second of the data sets which is recorded beforehand or afterwards, and the corrected phase values of the pixels in the second data set are in each case dependent at least on the phase measured value of the pixel at the same place in the first data set. Corrected image data sets are generated from the corrected phase values.

De-streaking algorithm for radial k-space data

Systems and methods include segmentation of a first image of a subject to identify locations of anatomical structures of the subject, determination of a region of interest of the subject based on the locations of anatomical structures, determination of a coil-mixing matrix based on the region of interest, control of an MR scanner to acquire radial trajectory k-space data of the subject from each of a plurality of RF coils of the MR scanner, application of the coil-mixing matrix to the radial trajectory k-space data of the subject acquired from each of the plurality of RF coils to generate first radial trajectory k-space data, reconstruction of a second image of the subject based on the first radial trajectory k-space data, and display of the second image.

Method and system for simulating magnetic resonance echo-planar imaging artifact

A method and a system for simulating magnetic resonance echo-planar imaging artifacts. Firstly, for K-space artifacts, K-space data are restored through normal magnetic resonance images, and the K-space data are modified pertinently, and then images with artifacts are reconstructed; for susceptibility artifacts, a susceptibility model is constructed through normal magnetic resonance images, and the magnetic field distribution is reconstructed, and then the images with distortion artifacts are reconstructed. According to the present disclosure, a large number of artifact data sets with different artifact types and artifact degrees can be quickly created through a small number of normal images, thus laying a foundation for the research of identifying artifacts, eliminating or weakening artifacts. A simulation algorithm is designed according to the principle of generation of EPI sequence artifacts, and the obtained images such as stripe artifacts, Moer artifacts, Nyquist artifacts, susceptibility artifacts and the like have good scientificity, accuracy and interpretability.