Abstract: A computer-implemented method for reconstructing MRI images of a body includes the steps of: a) acquiring a set MRI signal samples (sq) at different k-space location along a k-space trajectory; b) acquiring or estimating a B0 inhomogeneity map ?B0(r), wherein B0 is a static magnetic field for polarizing nuclear spins of the body and r represents position in image space; c) initializing an image (f); d) updating the image by a performing a data-consistency operation in k-space, wherein conversion between image space and k-space is performed through a non-uniform discrete pseudo-Fourier transform operator taking into account the B0 inhomogeneity map obtained from step b) to correct for off-resonance effects; and e) further updating the image by using an image-correction neural network. A computer program product and a magnetic resonance imaging apparatus for carrying out such a method is also provided.

Abstract: A method of performing magnetic resonance imaging of a body using a magnetic resonance imaging scanner the method includes applying to the body a time-varying magnetic field gradient (Gx, Gy, Gz) defining a continuous trajectory (ST) in k-space complying with a set of constraints including constraints on maximum amplitude and maximum slew rate of the time-varying magnetic field gradient, such that sampling points (KS) belonging to the trajectory define a pseudo-random sampling of the k-space, approximating a predetermined target sampling density, the trajectory in k-space minimizing, subject to the set of constraints, a cost function defined by the difference between a first term, called attraction term, promoting consistency of the distribution of sampling points in k-space with the predetermined target sampling density, and a second term, called repulsion term, promoting separation in k-space between sampling points, the repulsion term being expressed as a sum of contributions corresponding to respective pa

Abstract: The invention relates to a material for use as a pad in high field and/or very high field magnetic resonance imaging instrument, comprising at least one polar solvent having a melting point of 14° C. to 50° C., a dispersant and a dielectric charge. The invention relates also to a pad used in field of high field and/or very high field magnetic resonance imaging made of at least such a material.

Abstract: 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.

Abstract: A method of performing magnetic resonance imaging of a body includes a) immerging the body in a static and substantially uniform magnetic field; b) exciting nuclear spins inside the body using at least one radio-frequency pulse; c) applying to the body a time-varying magnetic field gradient defining at least one trajectory (ST) in k-space and simultaneously acquiring samples of a magnetic resonance signal so as to perform a pseudo-random sampling (KS) of the k-space; and d) applying a sparsity-promoting nonlinear reconstruction algorithm for reconstructing a magnetic resonance image of the body; wherein, at least in a low-spatial frequency region of the k-space, the distance between any two adjacent points belonging to a same trajectory is lower than 1/FOV, FOV being the size of a field of view of the reconstructed image. A magnetic resonance imaging apparatus for carrying out such a method is also provided.

Abstract: A method of performing magnetic resonance imaging of a body using a magnetic resonance imaging scanner the method includes applying to the body a time-varying magnetic field gradient (Gx, Gy, Gz) defining a continuous trajectory (ST) in k-space complying with a set of constraints including constraints on maximum amplitude and maximum slew rate of the time-varying magnetic field gradient, such that sampling points (KS) belonging to the trajectory define a pseudo-random sampling of the k-space, approximating a predetermined target sampling density, the trajectory in k-space minimizing, subject to the set of constraints, a cost function defined by the difference between a first term, called attraction term, promoting consistency of the distribution of sampling points in k-space with the predetermined target sampling density, and a second term, called repulsion term, promoting separation in k-space between sampling points, the repulsion term being expressed as a sum of contributions corresponding to respective pa

Abstract: 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.

Abstract: A computer-implemented method of building a database of pulse sequences for parallel-transmission magnetic resonance imaging, includes a) for each of a plurality of subjects, determining an optimal sequence for the subject; b) for each subject, computing the values of the or of a different cost or merit function obtained by playing the optimal sequences for all the subjects; c) aggregating the subjects into a plurality of clusters using a clustering algorithm taking the values, or functions thereof, as metrics; d) for each cluster, determining an averaged optimal sequence for the cluster; e) receiving, as input, a set of features characterizing an imaging subject, comprising at least a morphological feature of the subject; f) associating the subject to one pulse sequence of the database based on the set of features using the computer-implemented classifier algorithm; and g) performing magnetic resonance imaging using the pulse sequence.

Abstract: The invention relates to a material for use as a pad in high field and/or very high field magnetic resonance imaging instrument, comprising at least one polar solvent having a melting point of 14° C. to 50° C., a dispersant and a dielectric charge. The invention relates also to a pad used in field of high field and/or very high field magnetic resonance imaging made of at least such a material.

Abstract: An antenna array includes a plurality of linear electromagnetic resonators having longitudinal axes oriented parallel to one another and not aligned, and at least one decoupling device arranged between two the linear electromagnetic resonators, wherein the decoupling device comprises a plurality of open-loop electromagnetic resonators that are matched to a frequency located in the bandwidth of the two the adjacent linear electromagnetic resonators, that are electrically insulated and that are arranged in a plurality of planes that are not parallel to a plane containing the longitudinal axes of the two the linear electromagnetic resonators. Nuclear magnetic resonance imaging apparatus comprising such an antenna array is also provided.

Abstract: A method of performing magnetic resonance imaging of a body includes a) immerging the body in a static and substantially uniform magnetic field; b) exciting nuclear spins inside the body using at least one radio-frequency pulse; c) applying to the body a time-varying magnetic field gradient defining at least one trajectory (ST) in k-space and simultaneously acquiring samples of a magnetic resonance signal so as to perform a pseudo-random sampling (KS) of the k-space; and d) applying a sparsity-promoting nonlinear reconstruction algorithm for reconstructing a magnetic resonance image of the body; wherein, at least in a low-spatial frequency region of the k-space, the distance between any two adjacent points belonging to a same trajectory is lower than 1/FOV, FOV being the size of a field of view of the reconstructed image. A magnetic resonance imaging apparatus for carrying out such a method is also provided.

Abstract: A computer-implemented method of building a database of pulse sequences for parallel-transmission magnetic resonance imaging, includes a) for each of a plurality of subjects, determining an optimal sequence for the subject; b) for each subject, computing the values of the or of a different cost or merit function obtained by playing the optimal sequences for all the subjects; c) aggregating the subjects into a plurality of clusters using a clustering algorithm taking the values, or functions thereof, as metrics; d) for each cluster, determining an averaged optimal sequence for the cluster; e) receiving, as input, a set of features characterizing an imaging subject, comprising at least a morphological feature of the subject; f) associating the subject to one pulse sequence of the database based on the set of features using the computer-implemented classifier algorithm; and g) performing magnetic resonance imaging using the pulse sequence.

Abstract: An antenna array includes a plurality of linear electromagnetic resonators having longitudinal axes oriented parallel to one another and not aligned, and at least one decoupling device arranged between two the linear electromagnetic resonators, wherein the decoupling device comprises a plurality of open-loop electromagnetic resonators that are matched to a frequency located in the bandwidth of the two the adjacent linear electromagnetic resonators, that are electrically insulated and that are arranged in a plurality of planes that are not parallel to a plane containing the longitudinal axes of the two the linear electromagnetic resonators. Nuclear magnetic resonance imaging apparatus comprising such an antenna array is also provided.