In one embodiment a magnetic resonance imaging method includes the steps of comparing a first image and a second image to determine whether there is a distorted region present in the first image or the second image, each of the first image and second image having a total field of view that is the distance of the image along an axis, assigning an affected field of view to a width of the distorted region, determining an acceleration factor by dividing the total field of view of one or both of the first image and the second image by the affected field of view, acquiring sampled image data according to the acceleration factor of one or both of the first image and the second image and applying a mask to a third image in the affected field of view.

A method for magnetic resonance imaging corrects non-stationary off-resonance image artifacts. A magnetic resonance imaging (MRI) apparatus performs an imaging acquisition using non-Cartesian trajectories and processes the imaging acquisitions to produce a final image. The processing includes reconstructing a complex-valued image and using a convolutional neural network (CNN) to correct for non-stationary off-resonance artifacts in the image. The CNN is preferably a residual network with multiple residual layers.

In a method and a magnetic resonance system to acquire MR data of a slice of a volume segment within an examination subject, a slice selection gradient is activated along a first direction that is orthogonal to the slice. An RF excitation pulse is radiated for selective excitation of the slice, a first phase coding gradient is activated along the first direction, and a second phase coding gradient is activated along a second direction. The second direction is orthogonal to the first direction. A readout gradient is activated along a third direction that is orthogonal to the first direction and the second direction. MR data are acquired while the readout gradient is activated. A number of phase coding steps for the second phase coding gradient is determined depending on the first phase coding gradient.

A method includes: accessing MRI data acquired from a joint area, the MRI data including a series of spatially mapped spectral data points; generating MRI images of the joint area; receiving information encoding a region of interest that encompasses a suspected metal particle deposition area over at least one of the MRI images; constructing magnetic field maps using the MRI data, each representing off-resonance frequency shifts over the joint area; removing a background of off-resonance field inhomogeneity from the magnetic field map such that the region of interest is free from off-resonance field inhomogeneity; identifying clusters from the magnetic field maps with the background of off-resonance field inhomogeneity removed, the clusters defined over a first dimension of offset frequencies and a second dimension of cluster volumes; and computing a quantitative metric by combining information from the identified clusters according to both the first dimension and the second dimension.

Phase variations of the transverse magnetization in magnetic resonance induced by superimposed physical phenomenae or by intrinsic deviations of the main magnetic B0 field are separated from Feature Space set by demodulation and deconvolution, either by electrical circuits or by equivalent computational methods, permitting mapping and measurement of these induced phase variations independent of Feature Space.

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.

In a method and apparatus for recording a magnetic resonance dataset of a volume of interest of an object, at least one gradient moment is calculated as a function of at least one jump in susceptibility that is present in the volume of interest, between two sections of the volume of interest. An excitation pulse is radiated and at least one compensation moment is activated in a part volume of the volume of interest, for the at least partial compensation of a gradient moment caused by the jump in susceptibility. The signal generated by the excitation pulse is read out.

Systems and methods employing spin editing techniques to improve magnetic resonance spectroscopy (MRS) and magnetic resonance spectroscopic imaging (MRSI) are discussed. Using these spin editing techniques, magnetic resonance signals of one or more non-target chemicals (chemicals whose signals are to be filtered out or suppressed) chemicals can be suppressed, so that the signal(s) of a set of target chemicals can be obtained without signals from the one or more non-target chemicals. Information about and differences between the molecular topologies of the first set of chemicals and the one or more unwanted chemicals can be used to design a sequence that suppresses the one or more unwanted chemicals while allowing acquisition of signal(s) from the first set of chemicals. These techniques can be employed to recover sharp peaks despite magnetic field inhomogeneities and susceptibility effects.

Methods and apparatus for operating an MRI system is provided. The disclosure provides a diffusion-prepared driven-equilibrium preparation for an imaging volume and acquiring 3-dimensional k-space data from said prepared volume by a plurality of echoplanar readouts of stimulated echoes. An excitation radio-frequency signal and first and second inversion RF signals are provided to define a field-of-view (FOV).

A magnetic field monitoring probe includes a first container having a sample configured to emit a magnetic resonance (MR) signal included therein; a radio frequency (RF) coil inserted into the first container and configured to receive an MR signal emitted from the sample; and a second container surrounding the first container and having a matching liquid injected thereinto.