Abstract: A radar-based environmental detection system for motor vehicles. The system includes at least one radar sensor for providing location data regarding objects in the environment of the motor vehicle, and including a neural network for converting the location data into an environmental model which represents spatio-temporal object data of the objects. The neural network is conditioned to give priority to outputting environmental models in which at least one predetermined physical relationship between the location data and the object data is satisfied.

Abstract: A method for operating an MR system with a gradient pulse amplifier unit that has an end stage connected to a gradient coil with switching elements is provided. The gradient pulse amplifier unit includes a modulator for actuating the switching elements, and lockout switches interconnected in signal paths from the modulator to the switching elements. The gradient pulse amplifier unit includes feeder circuit breakers interconnected in at least some signal paths from the modulator to the switching elements. The circuit breakers are connected in the associated signal paths downstream of the lockout switches. A gradstop unit configured to receive at least one shut-off signal and actuate the lockout switches and the feeder circuit breakers. When the gradstop unit receives a shut-off signal, the gradstop unit actuates the lockout switches to lock out and the feeder circuit breakers to output an actuation signal to the switching elements.

Abstract: A method for operating an MR system with a gradient power amplifier having at least one output stage that is connectable to a gradient coil, and having four switching elements connected to one another as an H-bridge includes, to operate the gradient coil, in alternation: switching the switching elements attached to a common first pole of a voltage supply to conductive and switching the switching elements attached to a common second pole of a voltage supply to blocking by inverting power drivers; and switching the switching elements attached to a common first pole of a voltage supply to blocking and switching the switching elements attached to a common second pole of a voltage supply to conductive by inverting power drivers. The switching elements attached to the first pole are switched by non-inverting power drivers, and the switching elements attached to the second pole are switched by inverting power drivers.

Abstract: A method for operating an MR system with a gradient pulse amplifier unit that has an end stage connected to a gradient coil with switching elements is provided. The gradient pulse amplifier unit includes a modulator for actuating the switching elements, and lockout switches interconnected in signal paths from the modulator to the switching elements. The gradient pulse amplifier unit includes feeder circuit breakers interconnected in at least some signal paths from the modulator to the switching elements. The circuit breakers are connected in the associated signal paths downstream of the lockout switches. A gradstop unit configured to receive at least one shut-off signal and actuate the lockout switches and the feeder circuit breakers. When the gradstop unit receives a shut-off signal, the gradstop unit actuates the lockout switches to lock out and the feeder circuit breakers to output an actuation signal to the switching elements.

Abstract: A method for operating an MR system with a gradient power amplifier having at least one output stage that is connectable to a gradient coil, and having four switching elements connected to one another as an H-bridge includes, to operate the gradient coil, in alternation: switching the switching elements attached to a common first pole of a voltage supply to conductive and switching the switching elements attached to a common second pole of a voltage supply to blocking by inverting power drivers; and switching the switching elements attached to a common first pole of a voltage supply to blocking and switching the switching elements attached to a common second pole of a voltage supply to conductive by inverting power drivers. The switching elements attached to the first pole are switched by non-inverting power drivers, and the switching elements attached to the second pole are switched by inverting power drivers.

Abstract: Methods and systems for controlling patient stimulating effects in MR imaging. The methods and systems include calculating a first effective stimulus duration independently for each pulse flank of an MRI sequence individually and calculating a second effective stimulus duration for which a respective history of a changing gradient field during the sequence is taken into account. Dependent on an evaluation of both the first and second effective stimulus durations a threshold value for an allowable rate of change in the magnetic gradient field is then calculated. The respective MRI sequence is then evaluated against the calculated threshold value to determine whether or not the respective MRI sequence is safe to apply.

Abstract: In a method for operating a magnetic resonance (MR) facility during recording of MR data by using a MR sequence including a saturation module for a spin type to be saturated, in which a high-frequency saturation pulse is emitted between first and second spoiler gradient pulses, and multiple further gradient pulses apart from the spoiler gradient pulses, eddy current data is determined. The eddy current data describes eddy currents existing during emission of the saturation pulse and resulting from the further gradient pulses. Further, a pulse parameter of the first spoiler gradient pulse is selected based on the eddy current data such that the eddy currents generated by the first spoiler gradient pulse compensate for at least part of the eddy currents described by the eddy current data during emission of the saturation pulse. The facility is controlled to emit the first spoiler gradient pulse with the selected pulse parameter.

Abstract: A method and system for determining a magnetic field map in a MR system based on position of a movable patient support of the MR system are provided, wherein a first resulting field map including position dependent information about a magnetic field distribution in a homogeneity volume including an examination volume of the MR system is provided when the movable patient support is located at a first position, wherein a stationary field map including information about a magnetic field distribution in the homogeneity volume is provided, which is independent of the position of the movable patient support, wherein a position dependent field map including information about a magnetic field distribution in the homogeneity volume mainly influenced by a position of the movable patient support is determined using the stationary field map and the first resulting field map, and wherein a second resulting field map in the homogeneity volume is determined when the movable patient support is located at a second position di

Abstract: In a method and apparatus for determination of phase distributions in MR imaging, a measured phase distribution of the region of interest is combined with at least one second phase value to form a combination-phase distribution, wherein the phase values of the combination-phase distribution are restricted to a defined presentation interval. A correction-phase distribution is generated, based on a known magnetic field distribution in the region of interest. The phase values thereof are not restricted to the defined presentation interval. A corrected combination-phase distribution is generated using the correction-phase distribution and the combination-phase distribution, in which the phase values are restricted to the defined presentation interval. An absolute combination-phase distribution is generated from the corrected combination-phase distribution, in which the phase values are not restricted to the defined presentation interval.

Abstract: Methods and systems for controlling patient stimulating effects in MR imaging. The methods and systems include calculating a first effective stimulus duration independently for each pulse flank of an MRI sequence individually and calculating a second effective stimulus duration for which a respective history of a changing gradient field during the sequence is taken into account. Dependent on an evaluation of both the first and second effective stimulus durations a threshold value for an allowable rate of change in the magnetic gradient field is then calculated. The respective MRI sequence is then evaluated against the calculated threshold value to determine whether or not the respective MRI sequence is safe to apply.

Abstract: A method for recording a B0 map of a main magnetic field of a magnetic resonance device in an imaging volume of which an object to be recorded is arranged includes scanning a recording region to be covered by the B0 map by the magnetic resonance device. The recording region is scanned by a map recording sequence slice-by-slice in successive slices in a slice selection direction extending in a phase encoding direction and a readout direction, or three-dimensionally using two phase encoding directions and one readout direction in order to ascertain the B0 map. In a preliminary scan, the magnetic resonance device ascertains extension information describing the extension of the object using a scout sequence, which is used to define the recording region in sequence parameters of the map recording sequence and/or to adjust at least one sequence parameter of the map recording sequence.

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: In a method for operating a magnetic resonance (MR) facility during recording of MR data by using a MR sequence including a saturation module for a spin type to be saturated, in which a high-frequency saturation pulse is emitted between first and second spoiler gradient pulses, and multiple further gradient pulses apart from the spoiler gradient pulses, eddy current data is determined. The eddy current data describes eddy currents existing during emission of the saturation pulse and resulting from the further gradient pulses. Further, a pulse parameter of the first spoiler gradient pulse is selected based on the eddy current data such that the eddy currents generated by the first spoiler gradient pulse compensate for at least part of the eddy currents described by the eddy current data during emission of the saturation pulse. The facility is controlled to emit the first spoiler gradient pulse with the selected pulse parameter.

Abstract: In a method and apparatus for determining at least one patient-specific safety parameter for a medical imaging examination conducted on the patient by a medical imaging device, position data of the patient are acquired by a position data detector while the patient is on a patient-positioning device of the medical imaging apparatus. The acquired position data are evaluated in a processor in order to determine position information of the patient. The patient-specific safety parameter is determined using the position information of the patient.

Abstract: In a magnetic resonance apparatus having a scanner that generates a basic magnetic field in an imaging volume, and an operating method to acquire data from an entirety of a recording volume, wherein the scanner has a global shim coil acting on the entire imaging volume, and a local shim coil acting, with the global shim coil, on a sub-volume containing a region of interest, a first adjustment volume is established that contains the recording volume. A smaller, second adjustment volume is established containing the region of interest, and at most, the sub-volume. Using a field map of the basic magnetic field that covers the first adjustment volume, shim currents are respectively identified for the global shim unit, for homogenizing the first adjustment volume, and for the local shim unit, for homogenizing the second adjustment volume, accounting for the effect of the first shim currents on the second adjustment volume.

Abstract: In a method and magnetic resonance apparatus for determining a shim setting in order to increase a homogeneity of the basic magnetic field of the scanner of the apparatus by operating a shim element, information is obtained concerning the dependence of an induced field of the shim element on a set shim setting. A first field map is recorded and a first shim setting for the shim element is determined based on the first field map. A second field map is recorded while the shim element is driven with the first shim setting. A field induced by the shim element by the first shim setting is determined based on the first field map and the second field map. A second shim setting for the shim element is determined based on the determined induced field and the acquired information.

Abstract: A method is for carrying out an automatic adjustment of an MR system, including a number of receive coils. In such cases, a number of partial spectra in a number of receive coils are measured for an excitation volume of an examination object. The number of partial spectra are evaluated via an algorithm, at least one characteristic value being determined for each partial spectrum and a decision being further made with the aid of the number of characteristic values to determine whether the partial spectra fulfill a quality criterion. Finally, adjustment parameters of the MR system are optimized on the basis of the number of partial spectra.

Abstract: In a method for operating a medical imaging apparatus having multiple sub-systems controlled by a controller in a coordinated manner in order to perform a measurement sequence, a number of first setting parameters are chosen to be constant for a complete measurement sequence, and after a static adjustment, a dynamic adjustment of second setting parameters, which are defined by control signals for the measurement sequence and that can vary while a measurement sequence is being performed, takes place. Base data defining underlying conditions specific to the patient to be imaged are measured for the total imaging volume in a measurement sequence. Reference values for the setting parameters that affect the underlying conditions are saved in association with the base data during the measurement sequence.

Abstract: A method and system for determining a magnetic field map in a MR system based on position of a movable patient support of the MR system are provided, wherein a first resulting field map including position dependent information about a magnetic field distribution in a homogeneity volume including an examination volume of the MR system is provided when the movable patient support is located at a first position, wherein a stationary field map including information about a magnetic field distribution in the homogeneity volume is provided, which is independent of the position of the movable patient support, wherein a position dependent field map including information about a magnetic field distribution in the homogeneity volume mainly influenced by a position of the movable patient support is determined using the stationary field map and the first resulting field map, and wherein a second resulting field map in the homogeneity volume is determined when the movable patient support is located at a second position di

Abstract: A method for recording a B0 map of a main magnetic field of a magnetic resonance device in an imaging volume of which an object to be recorded is arranged includes scanning a recording region to be covered by the B0 map by the magnetic resonance device. The recording region is scanned by a map recording sequence slice-by-slice in successive slices in a slice selection direction extending in a phase encoding direction and a readout direction, or three-dimensionally using two phase encoding directions and one readout direction in order to ascertain the B0 map. In a preliminary scan, the magnetic resonance device ascertains extension information describing the extension of the object using a scout sequence, which is used to define the recording region in sequence parameters of the map recording sequence and/or to adjust at least one sequence parameter of the map recording sequence.