Abstract: Techniques are described for complex preprocessing steps to ensure consistency of sorted sets of reference measurement data, which have conventionally been required when sorting reference measurement data sets for DPG algorithms captured using an EPI technique, to be omitted because items of reference measurement data captured via the described techniques are already consistent in themselves. Therefore, for each polarity of the read-out gradients, a set of fully sampled reference measurement data is available, which is already suitable for carrying out a dual-polarity (DP) algorithm without any further measures.

Abstract: In a method for measuring a gradient field in a magnetic resonance tomography (MRT) system, a first slice is excited by a first radio frequency (RF) pulse being emitted and by a first slice selection gradient being switched at least partly at the same time as the first RF pulse. A second slice is excited by a second RF pulse being emitted and by a second slice selection gradient being switched at least partly at the same time as the second RF pulse. The second slice intersects with the first slice in an intersection region. After the excitation of the second slice, a readout gradient is switched, and an MR signal emitted from the intersection region is acquired. Depending on the MR signal, a disruption variable is computed, which determines a deviation of a temporal course of an amplitude of the readout gradient from a predetermined required course.

Abstract: A method for calibrating gradient amplifiers of a magnetic resonance apparatus is provided. The magnetic resonance apparatus includes one or more gradient coils that include at least two coil segments configured to generate a gradient magnetic field with a gradient in a spatial direction, and a gradient amplifier for each of the at least two coil segments. The gradient amplifier is configured to supply the respective coil segment with electric current. A plurality of magnetic field distributions are measured, each being generated via at least one coil segment of the at least two coil segments. For measuring each magnetic field distribution of the plurality of magnetic field distributions, the at least one coil segment that generates the respective magnetic field distribution is supplied with a predetermined electric current via the respective gradient amplifier. The gradient amplifiers are calibrated via a comparison of the plurality of measured magnetic field distributions.

Abstract: In a method for ascertaining correction information for correcting a magnetic resonance imaging scan, respective first and second magnetic resonance data for at least one gradient direction are acquired, where the first magnetic resonance data is acquired while the magnetic field gradient is applied in the respective gradient direction, and the second magnetic resonance data is acquired while the magnetic field gradient is applied counter to the respective gradient direction. The method may further include determining a respective phase difference for reference points along a respective position space line in the position space that extends in the respective gradient direction based on the first and second magnetic resonance data, and providing the phase differences of at least one subgroup of the reference points as correction information or ascertaining the provided correction information based on the phase differences of at least the subgroup of the reference points.

Abstract: The disclosure relates to gradient delay time correction of magnetic resonance data. For recording the magnetic resonance data, use is made of a three-dimensional recording technique with linear recording trajectories oriented in different readout directions of a readout plane that is perpendicular to a partition direction. Calibration data is recorded which covers a plurality of partitions in partition direction and which describes readout-direction-dependent shifts, caused by delay effects, of measurement points, e.g. sampled k-space sections in the k-space. Correction data is determined by evaluating the calibration data, and the magnetic resonance data is corrected on the basis of the correction data in order to compensate for the delay effects. The calibration data, which covers a coverage region in partition direction, is recorded in a resolved manner in partition direction, and at least one acceleration technique is applied in the partition direction during the recording of the calibration data.

Abstract: A computer-implemented method for gradient delay time correction of MR data using an MR device, wherein the magnetic resonance data is recorded using a three-dimensional recording technique with linear recording trajectories which are oriented in different readout directions of a readout plane that is perpendicular to a partition direction. The method includes: in a calibration measurement using the magnetic resonance device, recording calibration data which describes readout-direction-dependent shifts, caused by delay effects, of measurement points in the k-space; determining correction data by evaluating the calibration data; correcting the MR data based on the correction data in order to compensate for the delay effects, wherein the calibration data, which covers a coverage region in partition direction is recorded in a resolved manner, and the correction data is determined and applied in a manner that is dependent on partition direction.

Abstract: Techniques are described for complex preprocessing steps to ensure consistency of sorted sets of reference measurement data, which have conventionally been required when sorting reference measurement data sets for DPG algorithms captured using an EPI technique, to be omitted because items of reference measurement data captured via the described techniques are already consistent in themselves. Therefore, for each polarity of the read-out gradients, a set of fully sampled reference measurement data is available, which is already suitable for carrying out a dual-polarity (DP) algorithm without any further measures.

Abstract: Method for separating measurement data of an examination object, which data was acquired in collapsed form simultaneously for slices using an EPI SMS technique, into measurement data of individual slices, first and second sets of reference measurement data for separating the measurement data are acquired for each of the slices using a GRE acquisition technique, wherein the reference measurement data in the first set is acquired during switching of readout gradients of a first polarity, and the reference measurement data in the second set is acquired during switching of readout gradients of a second polarity. Based on the two sets of reference measurement data, corresponding separate first calibration data is determined from the reference measurement data acquired using a GRE acquisition technique while switching readout gradients of a first polarity, and second calibration data is determined from the reference measurement data acquired while switching readout gradients of a second polarity.

Abstract: Eddy current induced magnetic fields (MF) are compensated in a magnetic resonance imaging system. An MR-sequence (M) includes a number of gradients. A dataset includes values of an amplitude and a time constant of eddy current fields of a number of gradients on at least one gradient axis. A number of points in time within the time period of the MR-sequence are defined. A number of constant currents are calculated for a number of coils of the magnetic resonance imaging system based on the dataset. The number of constant currents is designed to compensate at least at the one defined point in time (PT1, PT2). The calculated number of constant currents are applied on the related coils prior or during the application of the MR-sequence or a section of the MR-sequence.

Abstract: A method for determining a parameter setting for a gradient power of a magnetic resonance system by an electronic computing device. The method includes specifying a limit value for a nerve stimulation in the case of a person positioned in the magnetic resonance system, entering at least one gradient parameter for a pulse of the gradient power as the parameter setting by an input device of the electronic computing device, approximating a potential nerve stimulation as a function of the at least one gradient parameter by a predefined mathematical model of the electronic computing device, comparing the approximated potential nerve stimulation with the predefined limit value by the electronic computing device, and determining the parameter setting as a function of the comparison.

Abstract: A method for operating a magnetic resonance facility in which a measurement gradient pulse is used to record magnetic resonance signals for sampling k-space along a trajectory section. The recorded magnetic resonance signals are assigned to k-space points using a shape function describing the time profile of the measurement gradient pulse. To correct deviations of the real time profile of the measurement gradient pulse from an assumed target profile, a first correction measurement is performed to ascertain first magnetic resonance signals of the trajectory section. A second correction measurement is then performed using a reference sampling pattern or a reference gradient pulse with fewer deviations from an assigned reference target profile. If a deviation criterion is met, a correction function for the shape function is ascertained by aligning the first and second magnetic resonance signals to one another, providing correction information to be used in an imaging measurement.

Abstract: A method for calibrating gradient amplifiers of a magnetic resonance apparatus is provided. The magnetic resonance apparatus includes one or more gradient coils that include at least two coil segments configured to generate a gradient magnetic field with a gradient in a spatial direction, and a gradient amplifier for each of the at least two coil segments. The gradient amplifier is configured to supply the respective coil segment with electric current. A plurality of magnetic field distributions are measured, each being generated via at least one coil segment of the at least two coil segments. For measuring each magnetic field distribution of the plurality of magnetic field distributions, the at least one coil segment that generates the respective magnetic field distribution is supplied with a predetermined electric current via the respective gradient amplifier. The gradient amplifiers are calibrated via a comparison of the plurality of measured magnetic field distributions.

Abstract: A method for operating a magnetic resonance facility in which a measurement gradient pulse is used to record magnetic resonance signals for sampling k-space along a trajectory section. The recorded magnetic resonance signals are assigned to k-space points using a shape function describing the time profile of the measurement gradient pulse. To correct deviations of the real time profile of the measurement gradient pulse from an assumed target profile, a first correction measurement is performed to ascertain first magnetic resonance signals of the trajectory section. A second correction measurement is then performed using a reference sampling pattern or a reference gradient pulse with fewer deviations from an assigned reference target profile. If a deviation criterion is met, a correction function for the shape function is ascertained by aligning the first and second magnetic resonance signals to one another, providing correction information to be used in an imaging measurement.

Abstract: In a method for measuring a gradient field in a magnetic resonance tomography (MRT) system, a first slice is excited by a first radio frequency (RF) pulse being emitted and by a first slice selection gradient being switched at least partly at the same time as the first RF pulse. A second slice is excited by a second RF pulse being emitted and by a second slice selection gradient being switched at least partly at the same time as the second RF pulse. The second slice intersects with the first slice in an intersection region. After the excitation of the second slice, a readout gradient is switched, and an MR signal emitted from the intersection region is acquired. Depending on the MR signal, a disruption variable is computed, which determines a deviation of a temporal course of an amplitude of the readout gradient from a predetermined required course.

Abstract: In a method, an imaging sequence is irradiated into an examination region in which an examination object is located. The imaging sequence includes an acquisition section. The acquisition section includes acquiring a plurality of echo signals, each of which samples a k-space region of a k-space. The plurality of echo signals comprises a plurality of first echo signals and a plurality of second echo signals. The plurality of first echo signals and the plurality of second echo signals are generated from different magnetization configurations. The k-space regions sampled by the plurality of first echo signals sample the k-space in a different order to the k-space regions sampled by the plurality of second echo signals.

Abstract: The disclosure relates to a magnetic resonance tomography scanner and to a method for operating the magnetic resonance tomography scanner. The method includes determining a B0 field map. The method further includes determining an excitation of the nuclear spins to be achieved and a spectrally selective excitation pulse for transmission by a transmitter by way of an antenna as a function of the B0 field map. In the method, the excitation pulse is configured here to generate the excitation of the nuclear spins to be achieved in the patient. The excitation pulse is then output by way of the antenna.

Abstract: A computer-implemented method for provision of a result dataset having position information of a local radio-frequency coil, including: providing input data having at least magnetic resonance data, which is acquired by means of the local radio-frequency coil; determining a result dataset by applying a trained function to the input data, wherein the result dataset comprises position information for determining the position of the local radio-frequency coil; and providing the result dataset.

Abstract: Methods for automatically compensating eddy currents in a magnetic resonance apparatus include determining modified magnetic resonance sequence data by a compensation computing unit and performing a magnetic resonance measurement in which a gradient generating system generates magnetic field gradients based on the modified magnetic resonance sequence data.

Abstract: Light signals are converted into first electric signals by a first group of light-receiving elements, and the light signals are additionally converted into second electrical signals by a second group of light-receiving elements. The second group has a lower degree of sensitivity for converting the photons into an electric current than the first group. The first electric signals are used to ascertain the distance to an object by means of a time-correlated photon counting process depending on a starting time for the emission of the light signals. Furthermore, the second electric signals are used to determine the distance depending on the starting time but using a second signal processing different from the process used for the first electric signals.

Abstract: In a method for providing setting parameter sets for at least one measuring protocol described by protocol parameters for acquiring magnetic resonance data with a magnetic resonance facility, setting parameter set is determined for each of at least two temperature status categories of the magnetic resonance facility using a temperature model describing a development of a temperature status of at least one component of the magnetic resonance facility. The method also includes preventing overheating of the at least one component due to the measurement with the measuring protocol being repeated a maximum number of times for a specified number of repetitions.