In a computer-implemented method of training a machine learning based processor, the processor can be trained to derive image data from signal data sets of multiple spin echo sequences. The trained processor can be configured to perform image processing for Magnetic Resonance Imaging (MRI) to derive the image data.

A system and method are provided for producing at least one of an image or a map of a subject includes controlling a magnetic resonance imaging (MRI) system to perform a pulse sequence that includes a phase increment of an RF pulse selected to induce a phase difference between two echoes at different echo times (TE). The method also includes controlling the MRI system to acquire MR data corresponding to at least the two echoes at different TEs, deriving a static magnetic field (B0) map of the MRI system using the MR data corresponding to the two echoes, and using the B0 map and MR data from at least one of the two echoes, generate a map of T2 of the subject.

A method for generating a magnetic resonance imaging, MRI, image of a subject including applying a magnetic field B.sub.0 to the subject, applying a sequence of electromagnetic pulses to the subject, applying further magnetic field gradients in addition to the magnetic field B.sub.0, the magnetic field including first gradients and at least one second gradient; measuring signal echoes produced by the object in response to the electromagnetic pulses and the first and second magnetic field gradients; acquiring image data at a first spatial resolution from the signal echo produced by the object in response to the electromagnetic pulses and the first and second magnetic field gradients, and combining the image data acquired from signal echoes in order to produce at least one image of the object at a second spatial resolution.

A method for applying a diffusion-weighting gradient during acquisition of diffusion-weighted imaging signals from a selected portion of a nervous system of a subject. Planar diffusion-weighted spin-echo (DWSE) imaging signals and planar diffusion-weighted stimulated-echo (DWSTE) imaging signals can be obtained to provide a plurality of sets of imaging signals. At least one set of imaging signals includes DWSTE signals that are associated with a high-b-value. A signal difference between DWSE imaging signals and DWSTE imaging signals can be corrected based on respective sets of DWSE imaging signals and DWSTE imaging signals having b-values at or near zero.

Techniques are disclosed for capturing scan data of an examination object via a magnetic resonance system. The techniques include capturing a first set of a diffusion-weighted scan data by excitation and, in an acquisition phase, acquiring a first echo signal, wherein before the acquisition phase in a diffusion preparation phase, diffusion gradients are switched for diffusion encoding of the scan data, The techniques additionally include capturing a second set of non-diffusion-weighted scan data by excitation and, in an acquisition phase, acquiring a second echo signal, wherein before the acquisition phase, in a diffusion preparation phase, the same diffusion gradients are switched as are switched for diffusion encoding of the scan data of the first set of diffusion-weighted scan data, although they have no influence on the second echo signal. Diffusion-weighted and non-diffusion-weighted scan data is thereby captured, having identical disturbances caused by eddy currents induced by switched gradients.

To avoid discontinuities between echoes from becoming large level differences in a k-space and to reduce artifacts generated in a reconstructed image due to the discontinuities in the k-space, an MRI apparatus of the present invention uses phase characteristics of multiple echoes to be collected after a single RF excitation to control an arrangement order in the k-space where the multiple echoes are arranged when a pulse sequence of the fast spin echo method that collects the multiple echoes using a spin flip after a single RF excitation is executed. The arrangement is controlled so that echoes with small phase errors between the echoes at least near the center of the k-space are adjacent to each other.

The present disclosure relates to a method comprising: receiving (201) acquired k-space data of an object, reconstructing (203) an image from the acquired k-space data, generating (205) reconstructed k-space data from the reconstructed image, determining (207) delta k-space data as a difference between the acquired k-space data and the reconstructed k-space data, splitting (209) the k-space data into one or more data chunks, wherein each data chunk of the data chunks comprises a set of one or more samples having a set of k-space coordinates, for each set of k-space coordinates of the one or more sets of coordinates, selecting (211), from the delta k-space data, a residual data set having the set of k-space coordinates, inputting (213) at least part of the data chunks and corresponding residual data sets to a trained machine learning model, thereby obtaining from the trained machine learning model probabilities of motion corruption for each of the data chunks of the acquired k-space.

A system and method is provided for producing a map of a static magnetic field (B.sub.0) of a magnetic resonance imaging system. The method includes forming a first dataset by acquiring, with the MRI system, a first plurality of different echo signals occurring at a respective plurality of different echo times. The method also includes forming a second dataset by acquiring, with the MRI system, a second plurality of different echo signals occurring at a respective plurality of different echo times. The second dataset includes signals resulting from a magnetization transfer (MT) between free water and bound molecules. The method further includes generating MT-weighted maps using the first dataset and the second dataset, determining, using the MT-weighted maps, a phase difference between the first plurality of different echo signals, and using the phase differences, generate a corrected map of the static magnetic field (B.sub.0) of the MRI system.

A fat suppressed diffusion image determination apparatus, a corresponding method and a corresponding computer program determine a diffusion weighted magnetic resonance image (DWI) of an object. The fat suppressed diffusion image determination apparatus includes a diffusion reference image providing unit for providing a diffusion reference MR image of the object, a fat image determination unit for determining a fat image from the diffusion reference MR image, a diffusion weighted image providing unit for providing a diffusion weighted MR image of the object, a fat suppressed image determination unit for determining a fat suppressed diffusion weighted MR image using a combination of the diffusion weighted MR image and the fat image.

In a method for correction of a B0 field map measured with a magnetic resonance device, that describes deviations from a nominal field strength in the homogeneity area of the magnetic resonance device by deviations from a nominal frequency for protons bonded to water, the deviations being represented as Larmor frequency values for different picture elements shifted by chemical shifts, the B0 field map is recorded with spins of the fat and water protons not in phase. The B0 field map is segmented by evaluating the differences of the Larmor frequency values of adjacent picture elements of the B0 field map in at least two contiguous clusters. For each cluster, a decision is made on the basis of a smoothness criterion and a compactness criterion as to whether a cluster containing a majority of protons bonded into fat is involved. Clusters identified as containing a majority of protons bonded into fat are corrected by lowering the Larmor frequency values by the difference between the nominal frequency for protons bonded into water and the corresponding nominal frequency for protons bonded to fat.