Method for correcting the magnetic field gradient waveform in a magnetic resonance measurement including extracting an impulse response from the measured step response of a magnetic resonance system, determining the slew rate of the system during the step response measurement, modifying the desired output waveform such that the desired output waveform is constrained to within the slew rate and the bandwidth of the system, and determining the required pre-equalized input waveform.

In a method and a control sequence determination device for determining a magnetic resonance system control sequence includes at least one radio-frequency pulse train to be emitted by a magnetic resonance system, a target magnetization is acquired and a k-space trajectory is determined. A radio-frequency pulse train for the k-space trajectory is then determined in an RF pulse optimization method using a target function, wherein the target function includes a combination of different trajectory curve functions, of which at least one trajectory curve function is based on a trajectory error model. A method for operating a magnetic resonance system uses such a control sequence and a magnetic resonance system has such a control sequence determination device.

The present disclosure provides a system for MRI. The system may obtain MRI scan data of a subject by directing an MRI scanner to perform an MRI scan on the subject according to a first gradient waveform. The system may also determine a second gradient waveform based on the first gradient waveform and a gradient waveform determination model. The gradient waveform determination model may have been trained according to a machine learning algorithm. The system may further generate a target reconstruction image of the subject based on the second gradient waveform and the MRI scan data.

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).

A prescan is automated to the greatest extent practicable, allowing acquisition of a favorable image irrespective of skills of an operator, as well as minimizing the time related to the prescan. For a plurality of image types in imaging tasks, a comprehensive FOV including all FOVs respectively of a plurality of image types is set, and for the comprehensive FOV, it is determined whether or not an item adjusted by the prescan satisfies an allowable condition for each image type, and the prescan is executed to make an adjustment appropriate for the image type with the strictest condition, on the item not satisfying the allowable condition.

A system and method for performing accelerated k-space shift correction calibration scans for non-Cartesian trajectories is provided. The method can include applying an MRI sequence, performing a calibration scan based on the MRI sequence using the non-Cartesian trajectory to acquire k-space shift data, wherein one or more partitions are skipped during the calibration scan, interpolating the skipped one or more partitions using the k-space shift data from adjacent partitions, and calibrating the MRI system using the k-space shift data and the interpolated k-space shift data. In some embodiments, an acceleration factor Acc can be defined and the calibration scan acquires k-space shift data for only one partition in every Acc partitions.

The disclosure relates to a method for ascertaining a deviation of at least one gradient field of a magnetic resonance system from a reference. The method includes providing at least one first image data set and one second image data set of a phantom with isotropic diffusion properties, recorded with a diffusion-weighted imaging sequence, wherein the first image data set and the second image data set are recorded with different diffusion-weightings along a gradient direction to be tested of the gradient field using the magnetic resonance system. The method further includes ascertaining a map of apparent diffusion coefficients from the image data sets for at least a portion of the image points of the image data sets. The method further includes comparing the apparent diffusion coefficients with the reference.

The disclosure relates to a field camera and a method for measuring a magnetic field distribution using a magnetic resonance tomograph and the field camera. The field camera has a number of samples, which are distributed over a spatial volume to be measured, and a number of receive antennas. In an act of the method, a sensitivity matrix for the receive antennas, for each sample at each receive antenna, is captured using the magnetic resonance tomograph. In another act, antenna signals of the samples in a magnetic field to be measured are captured by the receive antennas, using the magnetic resonance tomograph. Finally, magnetic resonance signals of the individual samples are determined from the antenna signals as a function of the sensitivity matrix, using a controller. In a further act, the magnetic field strength at the location of the samples may be determined from the magnetic resonance signals.

In a sequence of emitting a plurality of refocus RF pulses after one excitation RF pulse, in order to suppress a cusp artifact at a known magnetic field distortion generation position regardless of an imaging condition, such as a slice thickness or an FOV, between an excitation RF pulse and an initial refocus RF pulse, by generating a phase shift to transverse magnetization at the position, and by applying an extremely small dephase gradient magnetic field in the phase encoding direction and/or in the slice encoding direction, a signal value of an NMR signal (echo signal) is suppressed at the position, and the cusp artifact is deteriorated.

A magnetic field monitoring probe includes a first container having a sample configured to emit a magnetic resonance (MR) signal included therein; a radio frequency (RF) coil inserted into the first container and configured to receive an MR signal emitted from the sample; and a second container surrounding the first container and having a matching liquid injected thereinto.