The invention relates to a method of MR imaging of a body (10) of a patient. It is an object of the invention to provide a method that enables efficient compensation of flow artifacts, especially for MR angiography in combination with Dixon water/fat separation. The method of the invention comprises the steps of: a) generating MR echo signals at two or more echo times by subjecting the portion of the body (10) to a MR imaging sequence of RF pulses and switched magnetic field gradients, wherein the MR imaging sequence is a Dixon sequence; b) acquiring the MR echo signals; c) reconstructing one or more single-echo MR images from the MR echo signals; d) segmenting the blood vessels from the MR images; e) detecting and compensating for blood flow-induced variations of the amplitude or phase in the single-echo MR images within the blood vessel lumen, and f) separating signal contributions from water and fat spins to the compensated single-echo MR images. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

The invention relates to a method of MR imaging of a body (10) of a patient. It is an object of the invention to provide a method that enables efficient compensation of image artefacts in combination with PROPELLER imaging. The invention proposes to combine k-space blades in image space, and not in k-space like in conventional PROPELLER imaging. Local image artefacts are detected and corrected in single-blade MR images. The artefact detection and correction in the image domain prior to combining the single-blade MR images into a final MR image results in an improved image quality by better suppression of local artefacts and, thus, an increased signal-to-noise. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

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.

The disclosure relates to magnetic resonance imaging triggered by a prospective acquisition correction sequence. The technique comprises determining repetition time and an acquisition window time of a single-shot fast spin echo sequence; determining the maximum imaging layer number N in each physiological movement cycle on the basis of the acquisition window time and the repetition time, where N is a positive integer greater than or equal to 2; and enabling the single-shot fast spin echo sequence to obtain M layers of imaging data within at least one acquisition window time when the prospective acquisition correction sequence generates a trigger signal, where M is a positive integer greater than or equal to 2 and less than or equal to N. According to the present disclosure, a plurality of layers of imaging data are obtained within a single acquisition window time, thereby increasing a scanning speed and shortening imaging time.

A method for providing an magnetic resonance imaging (MRI) with nonrigid motion correction of an object is provided. An MRI excitation is applied to the object. A magnetic field read out from the object using a plurality of sensor coils. Spatially localized motion estimates are obtained for each sensor coil of the plurality of sensor coils. The motion estimates are used for each sensor coil to provide motion correction.

An embodiment in accordance with the present invention provides concurrent measurement of motion during T2-weighted magnetic resonance imaging. The present invention combines T2 preparation, a module used to impart T2 contrast, and motion measurement, tracking, and/or correction. The present invention provides for the expedition of more efficient motion compensation during T2-weighted imaging. The proposed invention can be used to provide a variety of measurements of motion, with no overhead in imaging time. The proposed invention also enables T2 contrast imaging to be executed while a subject is breathing freely, without the additional time cost associated with the standard motion tracking methodologies.

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.

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.

For determination of motion artifact in MR imaging, motion of the patient in three dimensions is used with a measurement k-space line order based on one or more actual imaging sequences to generate training data. The MR scan of the ground truth three-dimensional (3D) representation subjected to 3D motion is simulated using the realistic line order. The difference between the resulting reconstructed 3D representation and the ground truth 3D representation is used in machine-based deep learning to train a network to predict motion artifact or level given an input 3D representation from a scan of a patient. The architecture of the network may be defined to deal with anisotropic data from the MR scan.

Provided is a method for compensating for tissue motion during magnetic resonance (MR) imaging, and an apparatus for use thereof. The method includes acquiring a plurality of short-time MR scan images; selecting a reference scan image from the acquired plurality of short-time MR scan images; defining a set of transformation images based on the acquired plurality of short-time MR scan images other than the selected reference scan image; registering the reference scan image and the defined set of transformation images; calculating an average of aligned, registered images of the defined set of transformation images; and generating a motion-corrected image based on the calculated average.