A method for reducing N/2 ghost or Nyquist ghost in magnetic resonance (MR) images is provided The method includes acquiring k-space dataset for an object using an echo planar imaging (EPI) sequence, dividing the k-space dataset into first partial k-space subset data related to positive echoes and second partial k-space subset data related to negative echoes, obtaining third partial k-space subset data that is N/2 or Nyquist ghost-free subset data, respectively registering the first partial k-space subset data and the second partial k-space subset data to a first portion of the third partial k-space subset data corresponding to positive echoes and a second portion of the third partial k-space subset data corresponding to negative echoes, combining the registered first partial k-space subset data and the registered second partial k-space subset data to form full k-space dataset, and reconstructing an image for the object based on the full k-space dataset.

The invention relates to a magnetic resonance imaging system (100) for determining an approximation (150) of an electric conductivity distribution within a three-dimensional anatomical structure of interest. The determining comprises acquiring a first set of (3-n)-dimensional magnetic resonance data (144), reconstructing a (3-n)-dimensional phase distribution (146) using the (3-n)-dimensional magnetic resonance data (144), calculating a (3-n)-dimensional electric conductivity distribution (148) using spatial derivatives within the (3-n) dimensions and applying to the (3-n)-dimensional electric conductivity distribution (148) a scaling factor compensating for the relative reduction of dimensions by n.

Methods for reconstructing images from undersampled k-space data using a machine learning approach to learn non-linear mapping functions from acquired k-space lines to generate unacquired target points across multiple coils are described.

Described here are systems and methods for providing three-dimensional motion estimates prior to and during MRI-guided therapies. In general, these systems and methods can include simultaneous orthogonal plane imaging (SOPI), synthetic volumetric imaging (SVI), self-navigated phase-resolved 4D MRI, radial CAIPIRINHA, and combinations thereof.

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.

Method for MR imaging of an acquisition region during a patient examination. In order to determine a point spread function, in a prior measurement for each of additional gradient output directions, the method includes choosing, in the acquisition region, a slice lying outside of an isocenter of the MR device, which slice extends in a plane perpendicular to the additional gradient output direction under consideration; following a respective slice-selective excitation of the selected slice, acquiring first calibration data using the additional gradient pulse of the additional gradient output direction under consideration, and acquiring second calibration data omitting the additional gradient pulse in each case along a k-space line, wherein a same timing sequence of additional gradient pulse and readout time window is used as in the MR sequence; and calculating, from the first and second calibration data, the point spread function for the additional gradient output direction under consideration.

Various methods and systems are provided for acquiring a plurality blades of k-space data for magnetic resonance (MR) data acquisition. The plurality blades are arranged in a rotational manner around a center of the k-space. Each of the blades includes a plurality of parallel phase encoding lines indexed sequentially along a phase encoding direction of the blade. The phase encoding lines of each blade are sampled according to an asymmetric phase encoding order. The blade phase encoding orders of at least two adjacent blades are opposite to each other. This results in reducing shading and blurring artifacts in MRI images.

A variable density Cartesian sampling method that allows retrospective adjustment of temporal resolution, providing added flexibility for real-time applications where optimal temporal resolution may not be known in advance. The methods provide for a computationally efficient sampling methods where a first step includes producing a uniformly random sampling pattern using a golden ratio on a grid, and the second step is applying a nonlinear stretching operation to create a variable density sampling pattern. Diagnostic quality images may be recovered at different temporal resolutions.

A magnetic resonance imaging apparatus according to an embodiment includes sequence control circuitry and processing circuitry. The sequence control circuitry performs first data acquisition in a full k-space and performs a plurality of second data acquisition in partial k-spaces, each of the partial k-spaces being smaller than the entirety of the full k-space. The processing circuitry generates an image, based on data acquired from the first data acquisition and a plurality of pieces of data acquired from the plurality of second data acquisition.

Systems and methods for accelerated multi-contrast PROPELLER are disclosed herein. K-space is sampled in a rotating fashion using a plurality of radially directed blades around a center of k-space. A first subset of blades is acquired for a first contrast and a second subset of blades is acquired for a second contrasts. The first subset of blades is combined with high frequency components of the second subset of blades to produce an image of the first contrast. And the second subset of blades are combined with high frequency components of the first subset of blades to produce an image of the second contrast.