Abstract: Method for MR imaging of an acquisition region during a patient examination. In order to determine a point spread function, in a prior measurement for each of additional gradient output directions, the method includes choosing, in the acquisition region, a slice lying outside of an isocenter of the MR device, which slice extends in a plane perpendicular to the additional gradient output direction under consideration; following a respective slice-selective excitation of the selected slice, acquiring first calibration data using the additional gradient pulse of the additional gradient output direction under consideration, and acquiring second calibration data omitting the additional gradient pulse in each case along a k-space line, wherein a same timing sequence of additional gradient pulse and readout time window is used as in the MR sequence; and calculating, from the first and second calibration data, the point spread function for the additional gradient output direction under consideration.

Abstract: Techniques are disclosed to leverage the use of neural networks or similar machine learning algorithms to de-noise highly accelerated Wave-CAIPIRINHA scans. The described techniques facilitate the generation of 3D sequences using a greatly reduced scan time, with the resulting images having a high spatial resolution and an improved SNR compared to conventional approaches.

Abstract: Magnetic resonance (MR) data are acquired by applying magnetic fields to an examination region concurrent with stimulated echo signals, such that trajectories, which are not straight lines, are generated in k-space. For this purpose, sequence of RF pulses is applied to generate the stimulated echo signals in the examination object, undersampled MR measurement data are detected during reception of the stimulated echo signals in the at least two receiving coils, along the curved k-space trajectories, and fully sampled MR measurement are generated from the undersampled MR measurement data using sensitivity information of the at least two receiving coils. Alternatively, the MR measurement data are fully sampled in a central region of k-space, and a region outside the central region is not fully sampled, and a phase correction with a Partial Fourier technique is executed on the MR measurement data using fully sampled MR measurement data from the central region of k-space.

Abstract: A computer-implemented method for reconstructing a MRI image, including: receiving a plurality of MRI measurement data sets f1 to fN, wherein each data set is acquired from an examination object based on a different MRI protocol of an MRI system; receiving MRI images u10 to uN0 corresponding to the MRI measurement data sets f1 to fN; applying, in at least a first step GD1, trained functions to the MRI images u10 to uN0, using a neural network and a forward-sampling operator, wherein at least one output MRI image uT is generated; and providing the at least one output MRI image uT, wherein the forward-sampling operator determines an agreement between at least one MRI image u10 to uN0 and the corresponding MRI measurement data set f1 to fN.

Abstract: A method includes determining an initial magnetic resonance imaging, MRI, dataset (201) in image domain based on an initial reconstruction of MRI measurement data obtained using an undersampling scheme (400); and determining patches (231-233) of the initial MRI dataset (201) in accordance with a patching scheme, the patching scheme depending on the undersampling scheme (400); and, for each one of the patches (231-233): applying a machine-learned algorithm to obtain a respective patch (231-233) of a reconstructed MRI dataset, the machine-learned algorithm depending on the undersampling scheme (400); and combining the patches (231-233) of the reconstructed MRI dataset.

Abstract: Method for MR imaging of an acquisition region during a patient examination. In order to determine a point spread function, in a prior measurement for each of additional gradient output directions, the method includes choosing, in the acquisition region, a slice lying outside of an isocenter of the MR device, which slice extends in a plane perpendicular to the additional gradient output direction under consideration; following a respective slice-selective excitation of the selected slice, acquiring first calibration data using the additional gradient pulse of the additional gradient output direction under consideration, and acquiring second calibration data omitting the additional gradient pulse in each case along a k-space line, wherein a same timing sequence of additional gradient pulse and readout time window is used as in the MR sequence; and calculating, from the first and second calibration data, the point spread function for the additional gradient output direction under consideration.

Abstract: Techniques are disclosed to leverage the use of neural networks or similar machine learning algorithms to de-noise highly accelerated Wave-CAIPIRINHA scans. The described techniques facilitate the generation of 3D sequences using a greatly reduced scan time, with the resulting images having a high spatial resolution and an improved SNR compared to conventional approaches.

Abstract: Magnetic resonance (MR) data are acquired by applying magnetic fields to an examination region concurrent with stimulated echo signals, such that trajectories, which are not straight lines, are generated in k-space. For this purpose, sequence of RF pulses is applied to generate the stimulated echo signals in the examination object, undersampled MR measurement data are detected during reception of the stimulated echo signals in the at least two receiving coils, along the curved k-space trajectories, and fully sampled MR measurement are generated from the undersampled MR measurement data using sensitivity information of the at least two receiving coils. Alternatively, the MR measurement data are fully sampled in a central region of k-space, and a region outside the central region is not fully sampled, and a phase correction with a Partial Fourier technique is executed on the MR measurement data using fully sampled MR measurement data from the central region of k-space.

Abstract: In a method for controlling a radio-frequency transmitter of a magnetic resonance imaging apparatus to apply an inversion pulse to a sample magnetization, in a multi-shot readout phase, a gradient system of the magnetic resonance imaging apparatus is controlled to apply a steady-state gradient echo readout sequence having at least one first phase-encoding gradient along a first direction, at least one second phase-encoding gradient along a second direction, and a sequence of readout gradients along a readout direction. In the multi-shot readout phase, the gradient system is controlled to apply first AC gradients along the first direction and at least partly contemporaneously with readout gradients of the sequence of readout gradients, and the gradient system is controlled to apply second AC gradients along the second direction and at least partly contemporaneously with the readout gradients of the sequence of readout gradients.

Abstract: Methods for reducing scan time in magnetic resonance imaging (“MRI”), particularly when imaging three-dimensional image volumes, using a simultaneous time-interleaved multislice (“STIMS”) acquisition are described. The unused time in each repetition time (“TR”) period is exploited to provide an additional reduction in encoding time for a three-dimensional acquisition (e.g., a 3D whole brain coverage). Groups of spatially interleaved slices are excited in a single TR, with the excitation and acquisition of the groups of slices being interleaved in time.