A fully sampled calibration data set, which may be Cartesian k-space data, is used to obtain targeted and optimal interpolation kernels for non-regularly sampled data. The calibration data are self-calibration data obtained from a time-averaged image, or re-sampled data. ACS data are resampled for calibration of region-specific kernels. Subsequently, an explicit noise-based regularized solution can be utilized to estimate region-specific kernels for reconstruction.

Systems and methods include conversion of a first frame of k-space data acquired using a first initial readout polarity to first hybrid (k.sub.x, y)-space data, conversion of a second frame of k-space data acquired using a second initial readout polarity to second hybrid (k.sub.x, y)-space data, determination of a relationship between phase difference and y-position based on phase differences between a plurality of pixels located at k.sub.x=a of first hybrid (k.sub.x, y)-space data and a plurality of pixels at k.sub.x=b of second hybrid (k.sub.x, y)-space data, where a and b are constants, modification of the second hybrid (k.sub.x, y)-space data based on the relationship, conversion of the modified second hybrid (k.sub.x, y)-space data to a modified second frame of k-space data, generation of two single-polarity readout k-space frames based on the first frame of k-space data and the modified second frame of k-space data, and correction of a third frame of EPI image data based on the two single-readout polarity k-space frames.

A method for magnetic resonance imaging may include acquiring first k-space data that is generated by entering acquired magnetic resonance (MR) data into a plurality of first k-space locations. The method may further include synthesizing second k-space data for a plurality of second k-space locations that are not filled with the acquired MR data. The method may further include reconstructing an image from the first k-space data and the second k-space data by applying a reconstruction algorithm. The reconstruction algorithm is based at least in part on a neural network technique.

Various methods and systems are provided for a radio frequency coil array comprising a plurality of coil elements for magnetic resonance imaging. In one embodiment, a method includes grouping the plurality of coil elements into receive elements groups (REGs) according to REGs information, generating coil element sensitivity maps for the plurality of coil elements, generating REG sensitivity maps based on the REGs information and the coil element sensitivity maps, determining, for each REG, signals within a region of interest (ROI) and signals outside of the ROI based on the REG sensitivity maps, selecting one or more REGs based on the signals within the ROI and the signals outside of the ROI of each REG, and scanning the ROI with the coil elements in the selected REGs being activated and the coil elements not in any selected REGs being deactivated. In this way, phase wrap artifacts may be reduced.

In one embodiment, an MRI apparatus includes processing circuitry configured to: calculate phase correction data, which includes information on phase rotation amount due to non-uniformity of a static magnetic field, from MR signals; generate an image by using the phase correction data and the MR signals such that a signal from at least one of substances having different magnetic resonance frequencies in an imaging region of an object is suppressed in the image; generate first phase correction data composed of phase data that correspond to phase rotation amount selected from choices of phase rotation amount; calculate discontinuity of the first phase correction data; and generate second phase correction data by substituting at least part of the first phase correction data with non-selected phase data, which corresponds to phase rotation amount being not selected among the choices of phase rotation amount, depending on the discontinuity.

The invention relates to a method of Dixon-type MR imaging. It is an object of the invention to provide an MR imaging technique using bipolar readout magnetic field gradients with an improved estimation of the main field inhomogeneity to eliminate residual artifacts. In accordance with the invention, a method of MR imaging of an object placed in a main magnetic field within an examination volume of a MR device is proposed, wherein the method comprises the steps of: subjecting the object (10) to an imaging sequence to generate at least two sets of echo signals at two or more different echo times using bipolar pairs of readout magnetic field gradients, one set of echo signals being generated at a first echo time (TE1) and the other set of echo signals being generated at a second echo time (TE2), acquiring the echo signals from the object (10), reconstructing a first image from the echo signals attributed to the first echo time (TE1) and a second image from the echo signals attributed to the second echo time (TE2), computing modified first and second images by compensating for a fat shift in the reconstructed first and second images respectively, estimating phase errors in the acquired echo signals on the basis of the first and second images and the modified first and second images using a signal model including the resonance spectra of fat and water and the spatial variation of the main magnetic field, andreconstructing a water image and/or a fat image by separating the signal contributions of fat and water to the acquired echo signals using the estimated phase errors. Moreover, the invention relates to a MR device (1) and to a computer program to be run on a MR device (1).

A method is disclosed for phase contrast magnetic resonance imaging (MRI) comprising: acquiring phase contrast 3D spatiotemporal MRI image data; inputing the 3D spatiotemporal MRI image data to a three-dimensional spatiotemporal convolutional neural network to produce a phase unwrapping estimate; generating from the phase unwrapping estimate an integer number of wraps per pixel; and combining the integer number of wraps per pixel with the phase contrast 3D spatiotemporal MRI image data to produce final output.

In one embodiment, a Magnetic Resonance Imaging (MRI) apparatus includes: an RF coil configured to perform A/D conversion on a magnetic resonance (MR) signal received from an object and wirelessly transmit the MR signal; a main body configured to wirelessly receive the MR signal and generate a system clock; first communication circuitry configured to transmit the system clock by surface electric field communication using electric field propagation along a body surface of the object; and second communication circuitry provided in the RF coil and configured to receive the system clock transmitted by the surface electric field communication, wherein the RF coil is configured to operate based on the received system clock.

The present invention is directed to enabling high-accuracy Nyquist ghost correction without using a reference image.

After at least one of a plurality of images for use in diagnosis is used to perform low-order phase correction without causing aliasing of an image, a 2D phase map including remaining high-order phase errors and phase errors in a phase encode direction is calculated. The low-order phase correction is performed on a pair of pieces of data for image obtained by inverting a readout gradient magnetic field as image data for use in 2D phase map calculation, and positive-polarity/negative-polarity errors of the readout gradient magnetic field are calculated with odd lines and even lines of the pair of pieces of data for image rearranged. In the case of DWI imaging, an image with b-value=0 can be used for 2D phase map calculation.

A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry. The processing circuitry performs at least one of data collection for collecting first data of an imaging region of a subject at a plurality of time intervals after a tag pulse is applied to fluid flowing into the imaging region, and data collection for collecting second data of the imaging region by differing at least one of applying or not-applying the tag pulse and a position of the applying. The processing circuitry performs phase correction for at least one of the first data and the second data by using data in which the longitudinal magnetization of the fluid is a positive value, to generate an image for each time phase.