A method for multi-point magnetic resonance imaging including: receiving measured magnetic resonance data, which maps the magnetizations of a number of spin species in a measuring range with a number of echo times; carrying out an optimization for determining fitted magnetic resonance data on the basis of the measured magnetic resonance data, wherein an optimization function of the optimization implements a penalty for a higher rank of a matrix representing the fitted magnetic resonance data and a correction term for the localized evolution of a phase of the measured magnetic resonance data by means of field inhomogeneities or by means of a counterrotation of gradient fields with the number of echo times; and applying a spectral model to the fitted magnetic resonance data to determine magnetic resonance images with contrasts which correspond to the number of spin species.

A gradient system characterization function (e.g., a gradient system transfer function) may be developed by measuring a behavior of the MR device at a target temperature and developing at least one gradient system characterization function for a gradient coil of a magnetic resonance (MR) device at the target temperature based on the measured behavior. A patient may be subsequently imaged by the MR device, wherein the imaging process comprises measuring a temperature of a gradient coil, determining a gradient system characterization function at the measured temperature, calculating a pre-emphasized gradient of the gradient coil, and imaging the patient using the pre-emphasized magnetic field component.

Provided in embodiments of the present invention are a body mold, a magnetic resonance imaging system, and a main magnetic field evaluation method and a gradient field evaluation method therefor. The body mold comprises a plurality of substrates, wherein the plurality of substrates are sequentially arranged to form a multi-layer structure in a three-dimensional space. Each substrate is provided with a plurality of first accommodation bodies for accommodating first resonant volumes and a plurality of second accommodation bodies for accommodating second resonant volumes. The plurality of first accommodation bodies and the plurality of second accommodation bodies are arranged at intervals. The first resonant volumes and the second resonant volumes have different longitudinal relaxation times T1.

For k-space trajectory infidelity correction, a model is machine trained to correct k-space measurements in k-space. K-space trajectory infidelity correction uses deep learning. Trajectory infidelity is corrected from a k-space point of view. Since the image artifacts arise from k-space acquisition distortion, a machine learning model is trained to correct in k-space, either changing values of k-space measurements or estimating the trajectory shifts in k-space.

In a method for compensating stray magnetic fields in a magnetic resonance imaging system with two or more examination areas: a value for a predefined first magnetic field to be applied in a first examination area, in addition to a basic magnetic field is provided; information defining a predefined sequence control pulse to be applied in a second examination area is provided; a stray magnetic field in the second examination area resulting from application of the first magnetic field in the first examination area is determined; a compensated sequence control pulse for the second examination area is calculated from the predefined sequence control pulse and the determined stray magnetic field; and the compensated sequence control pulse is applied to the second examination area.

In an magnetic resonance imaging (MRI) system and a method for controlling a magnetic field gradient applied in the MRI system during an imaging sequence, a first gradient parameter representing a first maximum value of the applicable magnetic field gradients applied over time is determined in view heat generated by the applied magnetic field gradients. A second gradient parameter representing a second maximum value of the applicable magnetic field gradients applied over time is also determined in view heat generated by the applied magnetic field gradients, the second maximum value being different from the first maximum value. A current operating parameter of the MRI system is determined, and either the first gradient parameter or the second gradient parameter is selected for the imaging sequence, dependent on the determined current operating parameter.

Described here are systems and methods for correcting motion-encoding gradient nonlinearities in magnetic resonance elastography (“MRE”). In general, the systems and methods RF described in the present disclosure compute gradient nonlinearity corrected displacement data based on information about the motion-encoding gradients used when acquiring magnetic resonance data.

The disclosure relates to the automatic determination of correction factor values for producing MR images using a magnetic resonance system. A plurality of MR images is produced, wherein each MR image is produced using parameters with parameter values and using correction factors with correction factor values. In order to produce the MR images, MR data of the same examination object is acquired under the same external boundary conditions. The MR images are evaluated automatically in respect of artifacts in the respective MR image, in order to determine the MR image with the least artifacts among the MR images. The correction factor values are determined as those correction factor values which have been used to produce the MR image with the least artifacts. The parameters determine a sequence, with which the MR data is acquired for producing the MR images. The correction factors reduce influences which influence the acquisition of the MR data.

In a method for generating an image data set and a reference image data set: a first raw data set is provided that is acquired with a MR system and that includes measurement signals at read-out points in k-space that lie on a first k-space trajectory; a second raw data set is provided that is acquired with the same MR system and at the same examination object at read-out points that lie on a second, different k-space trajectory that is different from the first k-space trajectory; image data sets are reconstructed from the first raw data set; a reference image data set is reconstructed from the second raw data set; the reference image data set is compared with each image dataset to generate respective similarity values; and an image data set is selected having a greatest similarity value.

The invention provides for a magnetic resonance imaging system (100, 300, 500) with a gradient coil system (110, 112, 113) that comprises a set of gradient coils (110) configured for generating a gradient, a gradient coil amplifier (112), and a current sensor system (113) configured for measuring current sensor data (146) descriptive of the electrical current supplied to each of the set of gradient coils. Execution of the machine executable instructions causes a processor to: control (200) the magnetic resonance imaging system with the pulse sequence commands (142) to acquire magnetic resonance imaging data; record (202) the current sensor data during the acquisition of the magnetic resonance imaging data; calculate (204) a corrected k-space trajectory (150) using the current sensor data and a gradient coil transfer function (148); and reconstruct (206) a corrected magnetic resonance image (152) using the magnetic resonance imaging data and the corrected k-space trajectory.