Abstract: A control device establishes a change in a main magnetic field expected for a respective time instant and based on the established expected change in the main magnetic field, correctively adjusts the main magnetic field and/or a nominal receive frequency of the RF receive coil and/or a transmit frequency for subsequent RF transmit pulses and/or takes the expected change in the main magnetic field into account in the evaluation of the received MR signals. At least for some of the RF transmit pulses, the control device acquires, via a sensor device, a portion of the respective radiofrequency wave supplied to the RF transmit coil. The controller extracts therefrom an oscillation corresponding to a respiratory motion of the patient and based on the variation with time of the extracted oscillation, establishes the change in the main magnetic field expected for the respective time instant.

Abstract: Techniques are described for acquiring MR data comprising first MR data and second MR data of an examination object using an MR control sequence and a magnetic resonance device comprising an amplifier unit and an analog-to-digital converter (ADC).

Abstract: Techniques are disclosed for recording magnetic resonance data of an examination object with a magnetic resonance device. A magnetic resonance sequence is used to record the magnetic resonance data from at least two slices of a slice stack, and at least two temporally separate radio frequency pulses are output within an excitation time frame. A slice thickness of the slices, which is increased by an enlargement factor that is greater than one compared with a nominal slice thickness, is used for at least one, but not all, of the radio frequency pulses. The enlargement factor is selected as a function of a distance value describing the distance between two adjacent slices of the slice stack, such that the increased slice thickness does not result in the resulting excitation region of a slice extending into the adjacent slice.

Abstract: A method and an apparatus are provided for determining a valid parameter dataset for a protocol for an MRT examination by a MRT facility. The apparatus includes an input facility for importing a set of parameters to be used for performing the MRT examination; an interface for capturing at least one system value which represents an availability of a system resource for the MRT examination; a processor for calculating system resources required to perform the MRT examination using the imported parameters, and for executing a prepare function, which checks whether, with regard to the captured system values, the imported parameters are implementable in the MRT examination. If the parameters are not implementable, the processor is configured to calculate a modifying function for modifying the imported parameters based on the current system values and the required system resources and modify the imported parameters in accordance with the calculated modifying function.

Abstract: Techniques are disclosed for acquiring magnetic resonance data of an object with a magnetic resonance imaging apparatus. A slice group is imaged whose slices define a contiguous imaging volume and which contains a first number of slices. In a number of concatenations, the magnetic resonance data for subgroups of the slices, each containing a respective second number of slices depending on the first number of concatenations, are acquired, and shimming is performed to increase field homogeneity in the imaging volume. To define the subgroups, the imaging volume is subdivided into at least two disjoint contiguous sub-volumes, and at least two subgroups are defined for each sub-volume, each subgroup only containing non-adjacent slices in the sub-volume. During acquisition of the magnetic resonance data of each subgroup, shimming is at least restricted to the respective sub-volume.

Abstract: Acquisition of MR data with a compressed sensing technique in a volume section includes ascertaining an extent of magnetic field distortion within the volume section. A first gradient along a first direction is switched. An RF excitation pulse is radiated for selective excitation of a slice in the volume section while the first gradient is switched. The MR data is acquired in a volume of the volume section that is composed of the slice, a partial volume above the slice, and a partial volume below the slice by executing the following multiple times: switching a first phase-encoding gradient along a second direction; switching a second phase-encoding gradient along the first direction; and reading out the MR data in a k-space line while a readout gradient is switched along a readout direction. A set of k-space lines to be read out for the volume is determined in dependence on the extent.

Abstract: Techniques are disclosed relating to the generation of a magnetic resonance (MR) image of a predetermined portion of a volume of an examination object. MR data of the portion may be acquired using echo trains in a first step and in a second step, with each of the echo trains acquiring MR data of a plurality of k-space lines. The plurality of k-space lines extend parallel to one another and perpendicular to a common plane such that per k-space line, one intersection point within a plane results. The MR image is then reconstructed using the acquired MR data.

Abstract: In a method for detecting MR signals of an object in an MR scanner, in which the MR signals of the object are detected with receiving channels at the same time using a parallel imaging technique, where the MR signals are spin-echoes generated with a spin-echo based imaging sequence, a first magnetic field gradient (MFG) is applied in a slice selection direction (SSD) while applying an RF excitation pulse of the spin echo based imaging sequence, the first MFG having a first polarity during the application of the RF excitation pulse, a second MFG is applied in the SSD while applying at least a first RF refocusing pulse of the spin echo based imaging sequence, the second magnetic field gradient has a second polarity opposite to the first polarity, and the MR signals of the spin echo are detected to generate an MR image based on the detected MR signals.

Abstract: In a method and apparatus for generating a magnetic resonance data record, at least two excitation cycles are executed, wherein, in each excitation cycle, at least one magnetic resonance signal is recorded, using different phases with a first radio-frequency pulse in two consecutive excitation cycles, with at least one dephasing gradient being applied in an excitation cycle.

Abstract: An embodiment of a method for recording diagnostic measurement data of a knee of an examination object in knee imaging by a magnetic resonance device, includes performing an overview scan of the knee of the examination object, wherein overview measurement data is acquired in the overview scan, and performing diagnostic scans of the knee of the examination object based on the acquired overview measurement data, wherein two-dimensional diagnostic measurement data is acquired in the diagnostic scans.

Abstract: Techniques are disclosed related to recording a magnetic resonance image data set of a region of a patient with a magnetic resonance device using a multislice imaging technique. The multislice technique may be applied simultaneously with at least partial undersampling in a slice plane. The magnetic resonance data may be read out from a set of excited slices simultaneously and, by means of a slice separation algorithm that is calibrated using reference data recorded in a separate reference scan, may be allocated to the simultaneously read-out slices. Subsequently, an undersampling algorithm compensating for the undersampling in the slice plane may be applied to the undersampled magnetic resonance data of the individual slices.

Abstract: Techniques are described for generating an MR image of an object using a multi spin-echo based imaging sequence with a plurality of k space segments using a preparation pulse. The technique included acquiring a first k-space dataset of the object using a first echo time and a first delay after the preparation pulse before the several spin-echoes are acquired. The technique further includes acquiring a second k space dataset of the object using a second echo time and a second delay after the preparation pulse, with at least one of the second echo time and the second delay time being different from the corresponding first echo time and the first delay time, generating a combined k space, and generating the MR image based on the combined k space dataset.

Abstract: In a method and apparatus for recording a magnetic resonance dataset with a number of reception coils, wherein the measurement signals of the magnetic resonance dataset contain measurement signals from at least two slices, the measurement signals are recorded segmented by the measurement signals being recorded in a first area of k-space with a first scanning density and in a second area of k-space with a second scanning density.

Abstract: A method and system for suppressing metal artifacts in magnetic resonance (MR) images of slices of a patient containing a metallic implant. The method and system can use a Slice Encoding for Metal Artifact Correction (SEMAC) sequence. In the method and system, MR data of each slice is fully sampled in k-space in a reference region located in a center of k-space in a phase-encoding direction and a central section in a slice-selection direction. The MR-data of each slice outside the reference region can be undersampled in k-space. The fully sampled MR data from the reference regions of each slice can be combined to generate a reference data set for reconstructing an MR image of each slice.

Abstract: In a magnetic resonance tomography (MRT) apparatus and operating method, a field of view for imaging a target object is acquired. A relative position of this field of view in relation to a receiving space of the MRT scanner, in which the target object is received, is then automatically determined. A radio-frequency (RF) pulse to be used by the MRT scanner for imaging the target object is then automatically adjusted depending on this relative position. An excitation angle produced in the field of view by the RF pulse is changed compared to the use of the corresponding unadjusted RF pulse.

Abstract: Reference data is acquired by a slice multiplexing technique on the basis of which calibration data is determined and used to separate measurement data that has been acquired in collapsed form also by a slice multiplexing technique from at least two slices and still has to be separated into single-slice measurement data. As a result, both the reference data and the measurement data to be separated are acquired from several slices simultaneously in each case and hence during the same physiological state of motion in each case. This reduces the sensitivity to motion of a separation of the measurement data performed on the basis of the reference data.

Abstract: Generating a magnetic resonance image dataset includes providing a raw dataset that has been acquired such that the raw dataset is spatially and/or temporally undersampled. A regularization parameter is determined in an automated manner, and an image dataset is generated from the raw dataset using the regularization parameter in a compressed sensing technique.

Abstract: Techniques are disclosed for recording magnetic resonance data of an examination object with a magnetic resonance device. A magnetic resonance sequence is used to record the magnetic resonance data from at least two slices of a slice stack, and at least two temporally separate radio frequency pulses are output within an excitation time frame. A slice thickness of the slices, which is increased by an enlargement factor that is greater than one compared with a nominal slice thickness, is used for at least one, but not all, of the radio frequency pulses. The enlargement factor is selected as a function of a distance value describing the distance between two adjacent slices of the slice stack, such that the increased slice thickness does not result in the resulting excitation region of a slice extending into the adjacent slice.

Abstract: In a method for reconstructing contrast levels from magnetic resonance (MR) acquisitions using a parallel acquisition (PAT) technique, MR raw data for at least two contrast levels are generated or acquired, the raw data includes reference lines. Reference line images are reconstructed from the reference lines of the MR raw data for at least two of the contrast levels. A histogram analysis is implemented on the basis of the reference line images. A PAT reconstruction of image representations of the different contrast levels is implemented, wherein the decision as to which reference lines are used for the PAT reconstruction being made on the basis of the histogram analysis.

Abstract: In a magnetic resonance slice multiplexing method and apparatus, measurements are repeated with additional phase amounts being applied, wherein in each repetition, the additionally applied phase amounts are changed such that at least a central k-space region is fully sampled in the course of the repeated acquisitions. A calibration dataset, which is used in reconstructing image data for the simultaneously excited slices from the acquired measurement data, is determined from the measurement data that have been fully acquired in the central k-space region. The calibration dataset is updated in further measurements.