A system and method for magnetic resonance imaging is provided. The method includes dividing k-space into a plurality of regions along a dividing direction; scanning an object using a plurality of sampling sequences; acquiring a plurality of groups of data lines; filling the plurality of groups of data lines into the plurality of regions of the k-space; and reconstructing an image based on the filled k-space.

Phase unwrapping is provided for phase contrast magnetic resonance (MR) imaging. The velocity values are unaliased. For a given location over time, a path over time through a directed graph of possible velocities at each time is determined by minimization of derivatives over time. The possible velocities are based on the input velocity, the input velocity wrapped in a positive direction, and the input velocity wrapped in a negative direction, so the selection to create the minimum cost path represents unaliasing of any aliased velocities.

A system and method of mapping and correcting the inhomogeneity of a magnetic field within an object using an Magnetic Resonance Imaging (MRI) system where there is a single dominant resonance. The method includes acquiring at least three MRI images, each at different echo times (TE). At least two TE images (TE.sub.i=1 . . . N) are generated based on the at least three MRI images, wherein the subscripts I=1 . . . N refer to images with sequentially increasing TE times. Aliasing in the TE.sub.1 image is permitted. The T times of TE.sub.1 and TE.sub.2 are set such that the alias points at which wrapping occurs in TE.sub.1 does not overlap with the alias points of TE.sub.2. Each TE image is unwrapped. A final B.sub.0 map is set to the unwrapped TE.sub.N image.

In a magnetic resonance (MR) method system for slice-selective detection and correction of incorrect magnetic resonance data, a first acquisition sequence is implemented to acquire MR data from a first slice of the examination subject that is associated with a chronologically first coherence curve of the magnetization; a second acquisition sequence is implemented to acquire MR data from a second slice of the examination subject that is associated with a chronologically second coherence curve of the magnetization. In slice multiplexing measurement sequences that are characterized by the simultaneous use of the transverse magnetization of the first and second slice within the first and second acquisition sequences slice-selective errors can be detected and corrections made.

In a method for creating a composite magnetic resonance (MR) raw dataset for an MR apparatus, a first MR raw dataset is determined from a first partial section of an examination object, in which a first region of the first MR raw dataset is not filled with MR signals and in which a second region of the first MR raw dataset is filled with MR signals. An MR overview dataset is determined, which has been acquired with a number of reception coils of the MR apparatus and for which an overall field of view of the number of MR coils is larger than a reception region of the number of MR receive coils. A partial dataset is determined from the MR overview dataset, which has MR signals that originate from the first partial section of the examination object from which the first MR raw dataset originates. MR partial raw data are reconstructed for the first region of the MR raw dataset, using the partial dataset determined. The composite MR raw dataset is created from the second partial region of the first MR raw dataset and the MR partial raw data.

The present invention discloses a 3-dimension magnetic resonance imaging method which comprises: applying a slab selection gradient to a subject; transmitting a radiofrequency pulse to the subject, and exciting a slab of the subject to produce magnetic resonance signals with a continuous frequency bandwidth; performing a spatial encoding gradient across three dimensions to encode the magnetic resonance signals, wherein an equivalent encoded field of view which along the selected acceleration direction is controlled by the spatial encoding gradient, and the equivalent encoded field of view is shorter than the excited slab size of the subject; applying a separation gradient along with the spatial encoding gradient; and receiving and reconstructing the encoded magnetic resonance signals to produce 3D images.

In an EPI acquisition sequence for magnetic resonance signals k-space is scanned along sets of lines in k-space along opposite propagation directions, e.g. odd and even lines in k-space. Phase errors that occur due to the opposite propagation directions are corrected for in a SENSE-type parallel imaging reconstruction. The phase error distribution in image space may be initially estimated, calculated form the phase difference between images reconstructed from magnetic resonance signals acquired from the respective sets of k-space lines, or from an earlier dynamic.

Systems and methods for performing diffusion-weighted magnetic resonance imaging (MRI), including reconstructing and analyzing images, while preserving phase information that is traditionally discarded in such applications, are provided. For instance, background phase variations are eliminated, which enables complex-valued data analysis without the usual noise bias. As a result, the systems and methods described here provide an image reconstruction that enables true signal averaging, which increases signal-to-noise ratio (SNR) and allows higher contrast in diffusion model reconstructions without a magnitude bias.

Systems and methods for estimating the actual k-space trajectory implemented when acquiring data with a magnetic resonance imaging (MRI) system while jointly reconstructing an image from that acquired data are described. An objective function that accounts for deviations between the actual k-space trajectory and a designed k-space trajectory while also accounting for the target image is optimized. To reduce the computational burden of the optimization, a reduced model for the parameters associated with the k-space trajectory deviation and the target image can be implemented.

According to one of embodiments, an MRI apparatus includes at least one receiving coil configured to receive magnetic resonance signals from an object; and processing circuitry configured to generate an image based on the magnetic resonance signals, calculate a weighting map of the image based on at least one of a sensitivity characteristic of the receiving coil and a distance from a magnetic field center, and generate a quantitative susceptibility image, which quantitatively indicates magnetic susceptibility inside a body, from the image by using the weighting map.