In a method for determining at least one test position for a test measurement to be recorded by means of a magnetic resonance system, a test image is recorded, and at least one test position is selected based on the test image. With methods for the compensation of effects of deviations of gradients actually generated during a readout duration from gradients planned for this readout time duration, the selection of test positions according to the disclosure based on a test image advantageously ensures that the test positions lie in a recording region favorable for the test measurement, e.g. also within an examination object to be examined in the test image. A higher image quality in MR images, which were generated using test measurements carried out at test positions positioned according to the disclosure, can therefore be achieved.

A system and method are provided for magnetic resonance imaging (MRI) and/or image reconstruction that includes acquiring multi-pass, chemical shift-encoded (CSE)-MRI imaging data of a subject. The method further includes performing a complex, joint estimation of phase terms in the imaging data for each pass of the multi-pass, CSE-MRI imaging data to account for concomitant gradient (CG)-induced phase errors of different passes. The method also includes generating at least one of a proton density fat fraction (PDFF) estimate or an R*2 estimate that is unbiased by CG-induced phase errors using the phase terms and communicating a report that includes at least one of the PDFF estimate or the R*2 estimate.

Systems and methods for performing ungated magnetic resonance imaging are disclosed herein. A method includes producing magnetic resonance image MRI data by scanning a target in a low magnetic field with a pulse sequence having a spiral trajectory; sampling k-space data from respective scans in the low magnetic field and receiving at least one field map data acquisition and a series of MRI data acquisitions from the respective scans; forming a field map and multiple sensitivity maps in image space from the field map data acquisition; forming target k-space data with the series of MRI data acquisitions; forming initial magnetic resonance images in the image domain by applying a Non-Uniform Fast Fourier Transform to the target k-space data; and forming reconstructed images with a low rank plus sparse (L+S) reconstruction algorithm applied to the initial magnetic resonance images.

In a method for correcting an influence of an interference effect on a gradient system of a MR apparatus during a MR scan, a gradient pulse is emitted by an amplifier of the gradient system, a gradient sequence is established, an output signal of the amplifier is captured for the gradient pulse, a transfer function is established, and an output signal of the amplifier is established such that the gradient system provides an expected gradient sequence.

In a method for automatic control of an examination sequence in magnetic resonance (MR) system during recording of MR signals in an examination segment of a person being examined, which has two tissue components with two different MR resonant frequencies, an examination sequence for examination of the examination segment is determined. Further, whether the examination sequence includes an imaging sequence in which one of the two tissue components is to be suppressed and for which at least two different suppression options exist to reduce the one of the two tissue components during the recording of the MR signals is determined. In response to the determination that the examination sequencing included the imaging sequence, the method can include determining a sequence parameter of the examination for the imaging sequence; and selecting one of the at least two suppression options as a function of the sequence parameter determined for the imaging sequence.

A method, device, and system for reducing inhomogeneity in an imaging magnetic field during magnetic resonance imaging is described. The method includes generating a corrective magnetic field during imaging, the corrective magnetic field having a first magnetic field component and a second magnetic field component with a phase separation therebetween. The first and second components are generated according to a stability parameter decomposed from a stability field that correct an instability identified within the imaging magnetic field.

A plurality of reception coils are used to acquire magnetic resonance signals using parallel imaging and a k-space acquisition scheme, in which alternatingly the central region and one of the peripheral k-space portions are imaged in acquisition steps of a pair, such that after a partition number of such pairs, the whole k-space to be acquired has been imaged and a sliding reconstruction window can be applied to reconstruct an additional magnetic resonance image after each acquisition of such a pair. A time series of magnetic resonance images forming the magnetic resonance data set is then reconstructed from the magnetic resonance signals and sensitivity information regarding the plurality of reception coils by using the sliding reconstruction window and a reconstruction technique for undersampled magnetic resonance data. The k-space trajectories for each acquisition step are chosen to allow controlled aliasing in all three spatial dimensions including the readout direction.

According to some aspects, a method of suppressing noise in an environment of a magnetic resonance imaging system is provided. The method comprising estimating a transfer function based on multiple calibration measurements obtained from the environment by at least one primary coil and at least one auxiliary sensor, respectively, estimating noise present in a magnetic resonance signal received by the at least one primary coil based at least in part on the transfer function, and suppressing noise in the magnetic resonance signal using the noise estimate.

In a method for recording diffusion-weighted measurement data, using a MR system with diffusion weightings with two+ different b-values, diffusion directions and diffusion weightings with the associated b-values to be used for the desired recordings are loaded, a sequence of recordings of measurement data to be recorded consecutively are determined by sorting the diffusion directions and diffusion weightings to be recorded based on their associated b-value, such that the b-value of a recording of measurement data is less than the b-value of the immediately preceding recording of measurement data by no more than a predetermined threshold value, and the recordings are recorded based on the determined sequence. By arranging diffusion encodings for the desired recordings to be used consecutively, abrupt discontinuities in the b-values used chronologically are prevented, thereby eddy current effects from preceding recordings have time to abate in the case of recordings with small b-values.

A system and method are provided for producing at least one of an image or a map of a subject includes controlling a magnetic resonance imaging (MRI) system to perform a pulse sequence that includes a phase increment of an RF pulse selected to induce a phase difference between two echoes at different echo times (TE). The method also includes controlling the MRI system to acquire MR data corresponding to at least the two echoes at different TEs, deriving a static magnetic field (B0) map of the MRI system using the MR data corresponding to the two echoes, and using the B0 map and MR data from at least one of the two echoes, generate a map of T2 of the subject.