Selectively exciting bulk protons in certain tissue components, e.g. water, while suppressing the excitation of others, e.g. fat, can lead to images with better contrast for desired features. The invention provides binomial, off-resonance RF excitation pulses for differentiating tissue excitation that yields a larger fat suppression that prior art water excitation methods. Proper balancing of the frequency offset and the pulse duration with a relative phase offset between the pulses leads to large-bandwidth pass- and stopbands for water and fat, respectively. The pulses can be applied with short, or even zero, interpulse delay, leading to substantial time savings in the imaging sequence.

Described here are systems and methods for generating quantitative perfusion parameter maps based on different longitudinal relaxation parameter maps that are produced from images acquired using non-selective and selective magnetic resonance imaging (“MRI”) data acquisition techniques.

A system and method for performing accelerated k-space shift correction calibration scans for non-Cartesian trajectories is provided. The method can include applying an MRI sequence, performing a calibration scan based on the MRI sequence using the non-Cartesian trajectory to acquire k-space shift data, wherein one or more partitions are skipped during the calibration scan, interpolating the skipped one or more partitions using the k-space shift data from adjacent partitions, and calibrating the MRI system using the k-space shift data and the interpolated k-space shift data. In some embodiments, an acceleration factor Acc can be defined and the calibration scan acquires k-space shift data for only one partition in every Acc partitions.

In a method and magnetic resonance (MR) apparatus to acquire MR data from a subject, a predetermined spectral model of a multipoint Dixon technique is used that includes at least two spectral components with respective associated relaxation rates, a first phase due to field inhomogeneities; and a second phase due to eddy current effects. MR data are acquired using a bipolar multi-echo MR measurement sequence for multiple image points wherein, for each image point, the multi-echo MR measurement sequence alternately uses positive and negative readout gradient fields for the readout of MR signals of the MR data at at least three echo times. The at least two spectral components are determined based on the MR data.

A k-space data acquisition device and method, and a magnetic resonance imaging device and method. The k-space data acquisition device includes an acquisition trajectory determiner configured to determine an acquisition trajectory of echo signals in a k space in a manner of filling echo data in a pseudo radial order; and a data acquirer configured to acquire k-space data conforming to the acquisition trajectory and fill the k space.

A method for determining the solids content, fines content and/or particle size distribution of the solids in an oil sands process stream test sample comprising bitumen, solids and water using low-field time-domain NMR is provided which involves building a non-solids partial least squares calibration model using oil sands process streams calibration samples having a known bitumen content, solids content, water content, fines content and/or particle size distribution by subjecting the calibration samples to a first T.sub.1-weighted T.sub.2 measurement NMR pulse sequence that maximizes very fast relaxing signals and a second T1-weighted T2 measurement NMR pulse sequence that maximizes slow relaxing signals. The measurement of other sample properties strongly correlated with surface area, such as methylene blue index, can also be measured using a partial least squares calibration model.

Provided herein are adipose mimic compositions for use in MRI. The compositions of the invention mimic the MRI properties of human adipose tissue, including T1 relaxation kinetics, T2 relaxation kinetics, magnetic susceptibility, and chemical shift artifact. The compositions of the invention are readily manufactured from inexpensive materials. The compositions of the invention may be used in MRI system calibration or for implementing image correction techniques such as fat suppression.

A method of employing a central computer database (18) for supporting a characterization of tissue by magnetic resonance fingerprinting measurements, including steps of —exciting nuclei of a subject of interest by applying (50) a radio frequency excitation field B.sub.1 generated according to a magnetic resonance fingerprinting sequence (38), —acquiring (52) magnetic resonance imaging signal data from radiation emitted by excited nuclei of the subject of interest, —transferring (54) a magnetic resonance fingerprinting data set (42) to the central computer database (18), —retrieving (56) a predefined dictionary from the central computer database (18), —matching (60) the acquired magnetic resonance imaging signal data to the retrieved dictionary by applying a pattern recognition algorithm to determine a value (40) or a set of values (40) for at least one physical quantity (T.sub.1, T.sub.2), —adding (62) at least the determined value (40) or the determined set of values (40) as a new entry of an associated medical data set (36) to the central computer database (18), and —making (64) the new entry of an associated medical data set (36) accessible to users of the central computer database (18); and —a magnetic resonance fingerprinting data collection and analysis system (10) comprising a central computer database, a data receiving unit (20), a data output unit (22) and a data analysis device (26) configured to carry out the method.

Improved motion correction for magnetic resonance imaging is provided. An MR imaging method provides a first sequence of MR images and a second sequence of MR images where: 1) the two sequences are inherently spatially co-registered and synchronous with each other; 2) the first sequence includes signal variation due to one or more causes other than motion or deformation; and 3) the second sequence does not include the signal variation of the first sequence. In this situation, the second sequence can be used to perform motion correction for the first sequence. One example of this approach is Dixon MR imaging, where the water images are the first sequence and the fat images are the second sequence.

A method of operating a magnetic resonance imaging system (10) with regard to acquiring multiple-phase dynamic contrast-enhanced magnetic resonance images, the method comprising steps of acquiring (48) a first set of magnetic resonance image data (x.sub.pre) prior to administering a contrast agent to the subject of interest (20), by employing a water/fat magnetic resonance signal separation technique, determining (52) a first image of the spatial distribution of fat (I.sub.pre) of at least the portion of the subject of interest (20), acquiring (50) at least a second set of magnetic resonance image data (x.sub.2) of at least the portion of the subject of interest (20) after administering the contrast agent to the subject of interest (20), by employing a water/fat magnetic resonance signal separation technique, determining (54) at least a second image of the spatial distribution of fat (I.sub.2.sup.ph) of at least the portion of the subject of interest (20), applying (56) an image registration method to the second image of the spatial distribution of fat (I.sub.2.sup.ph) with reference to the first image of the spatial distribution of fat (I.sub.pre) for correcting a potential motion of the subject of interest (20); and a magnetic resonance imaging system (10) having a control unit (26) that is configured to carry out steps (56-64) of such a method; and a software module (44) for carrying out such a method, wherein the method steps (56-64) to be conducted are converted into a program code that is implementable in a memory unit (30) and is executable by a processor unit (32) of the magnetic resonance imaging system (10).