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.

Disclosed are a magnetic-resonance imaging method, apparatus and system, and a storage medium. The method includes acquiring an initial model of magnetic-resonance imaging and establishing an initial imaging model according to an iterative algorithm used for solving the initial model, where the iterative algorithm includes at least one of an undetermined parameter, an undetermined solving operator or an undetermined structural relationship; training the initial imaging model on the basis of sample data to generate a magnetic-resonance imaging model, where training of the initial imaging model is used for learning the at least one of the undetermined parameter, the undetermined solving operator or the undetermined structural relationship in the iterative algorithm; and acquiring under-sampled K-space data to be processed, inputting the under-sampled K-space data into the magnetic-resonance imaging model, and generating a magnetic-resonance image.

Methods, devices, systems and apparatus for determining emphysema thresholds for controlling magnetic resonance imaging are provided. In one aspect, a magnetic resonance imaging method includes: collecting magnetic resonance imaging data as first k-space data by undersampling a magnetic resonance signal, performing parallel imaging reconstruction on the first k-space data to obtain a first image, performing enhancement processing on the first image to obtain a second image that comprises distributional information of image supporting points, and performing constrained reconstruction on the first k-space data by using the second image as a prior image to obtain a third image as a magnetic resonance image to be displayed.

In one embodiment, an MRI apparatus includes a scanner and processing circuitry. The scanner includes at least two gradient coils. The processing circuitry is configured to cause the scanner to acquire k-space data for correction in a band-shaped two-dimensional k-space along a readout direction, or in a columnar three-dimensional k-space along a readout direction, while changing rotation angles, wherein each of the rotation angles corresponds to the readout direction, generate correction data for correcting an error due to a gradient magnetic field generated by the gradient coils, by using the acquired k-space data for correction, cause the scanner to acquire k-space data for reconstruction, based on a radial acquisition method, while correcting the gradient magnetic field by using the correction data, and generate an image by reconstructing the acquired k-space data for reconstruction.

A method may include obtaining a plurality of groups of imaging data. Each group of the plurality of groups of imaging data may be generated based on MR signals acquired by an MR scanner via scanning a subject using a diffusion sequence. The method may also include determining one or more correction coefficients associated with an error caused by the diffusion sequence for each group of the plurality of groups of imaging data. The method may also include determining, based on the one or more correction coefficients corresponding to the each group of the plurality of groups of imaging data, a plurality of groups of corrected imaging data. The method may further include determining averaged imaging data by averaging the plurality of groups of corrected imaging data in a complex domain and generating, based on the averaged imaging data, an MR image.

A computer-implemented method of removing truncation artifacts in magnetic resonance (MR) images is provided. The method includes receiving a crude image that is based on partial k-space data from a partial k-space that is asymmetrically truncated in at least one k-space dimension. The method also includes analyzing the crude image using a neural network model trained with a pair of pristine images and corrupted images. The corrupted images are based on partial k-space data from partial k-spaces truncated in one or more partial sampling patterns. The pristine images are based on full k-space data corresponding to the partial k-space data of the corrupted images, and target output images of the neural network model are the pristine images. The method further includes deriving an improved image of the crude image based on the analysis, wherein the derived improved image includes reduced truncation artifacts and increased high spatial frequency data.

A method of processing signals from an accelerated MRI scan of a dynamic event occurring in the body of a human patient. The patient is subjected to an MRI examination which includes the relevant portion of his body. Those voxels for which there is no substantially no change over the time of the scan are identified and subtracted from the overall scan signal.

A magnetic resonance (MR) image may be created from MR data by receiving the MR data, applying a transform to the MR data, where a result of the applying is an image space representation of the MR data, determining a wrapped phase map of the image space representation of the MR data, obtaining an unwrapped phase map based on the wrapped phase map, scaling the unwrapped phase map into a B0 field map, reconstructing the MR image based on the MR data, correcting the MR image based on the B0 field map, and outputting the MR image. The scaling may be free of accounting for effects on the MR data by artifact sources secondary to B0 field inhomogeneities.

Generation of artifacts caused by the FID signal is suppressed even when the parallel imaging is applied to the imaging using a spin echo type pulse sequence. In performing a pulse sequence of a spin echo type using an excitation RF pulse for exciting nuclear spin and an inversion RF pulse for inverting excited nuclear spin as a high-frequency magnetic field pulse, a high-frequency transmitter of a MRI apparatus changes the phase of the inversion RF pulse according to the phase encoding and the phase encoding number imparted for each echo signal. Specifically, the phase of the inversion RF pulse is controlled to be a quadratic function of the phase encode of the echo signal.

An image generating apparatus according to the embodiment includes processing circuitry. The processing circuitry acquires MR data acquired in read-out directions including a first read-out direction and a second read-out direction intersecting the first read-out direction, filter sensitivity distributions corresponding to the read-out directions and indicating distributions of sensitivity of a low-pass filter, and coil sensitivity distributions corresponding to coil elements used to acquire the MR data. The processing circuitry generates synthesis sensitivity distributions for the respective read-out directions by synthesizing the filter sensitivity distributions and the coil sensitivity distributions for the respective read-out directions. The processing circuitry generates an MR image based on the synthesis sensitivity distributions and MR data.