30 results about "Magnetic resonance spectroscopic imaging" patented technology

A method of magnetic resonance spectroscopic imaging of an object (O) including at least one chemical species to be imaged, comprising sampling of the k-space such that a plurality of N_ω first sampling trajectories through at least one k-space segment of the k-space is formed along a phase-encoding direction, each of said first sampling trajectories beginning in a central k-space region and continuing to a k-space border of the at least one k-space segment and having a duration equal to or below a spectral dwell time corresponding to the reciprocal spectral bandwidth, collecting at least one first set of gradient-echo signals obtained along said first sampling trajectories, collecting at least one second set of gradient-echo signals obtained along a plurality of N_ω second sampling trajectories, said N_ω second sampling trajectories and said N_ω first sampling trajectories being mutually mirrored relative to a predetermined k-space line in the central k-space region.

A method and apparatus for enhancing the spectral resolution of magnetic resonance spectroscopic (MRS) measurements include receiving time domain echo data from an MRS measurement for an MRS volume in a subject. Also received are high spatial resolution complex signal values within the MRS volume based on magnetic resonance imaging (MRI) measurements. Frequency-domain content is determined for the echo data based at least in part on the complex signal values. For example, in some embodiments, receiving complex signal values includes receiving high spatial resolution complex signal values within the MRS volume for each of two different echo time settings. The frequency-domain content of the echo data is corrected for a lineshape profile based on high resolution frequency dispersion values for the MRS volume determined from differences in the complex signal values for the two different echo time settings.

The present invention relates to a magnetic resonance spectroscopic imaging (MRSI) method, specifically to a magnetic resonance spectroscopic imaging method with up to three spatial dimensions and one spectral dimension. Interleaving dynamically switched magnetic field gradients into the spectroscopic encoding scheme enables multi-region shimming in a single shot to compensate the spatially varying spectral line broadening resulting from local magnetic field gradients. The method also employs sparse spectral sampling with controlled spectral aliasing and nonlinear sampling density to maximize encoding speed, data sampling efficiency and sensitivity.

A method for increasing sensitivity and/or specificity of a magnetic resonance spectroscopy imaging technique for detecting a neurodegenerative disease is provided. The method includes acquiring magnetic resonance spectroscopy data from the brain of a subject, while suppressing certain metabolites in the spectrum via a data acquisition protocol, to improve quantification accuracy for the remaining metabolites, and quantifying a metabolite concentration or a metabolite concentration ratio from the spectral data as an indicator of the neurodegenerative disease.

This invention relates to localized magnetic resonance spectroscopy (MRS) and to magnetic resonance spectroscopic imaging (MRSI) of the proton NMR signal, specifically to a magnetic resonance spectroscopy (MRS) method to measure a single volume of interest and to a magnetic resonance spectroscopic imaging method with at least one spectral dimension and up to three spatial dimensions. MRS and MRSI are sensitive to movement of the object to be imaged and to frequency drifts during the scan that may arise from scanner instability, field drift, respiration, and shim coil heating due to gradient switching. Inter-scan and intra-scan movement leads to line broadening and changes in spectral pattern secondary to changes in partial volume effects in localized MRS. In MRSI movement leads to ghosting artifacts across the entire spectroscopic image. For both MRS an MRSI movement changes the magnetic field inhomogeneity, which requires dynamic reshimming. Frequency drifts in MRS and MRSI degrade water suppression, prevent coherent signal averaging over the time course of the scan and interfere with gradient encoding, thus leading to a loss in localization. It is desirable to measure object movement and frequency drift and to correct object motion and frequency drift without interfering with the MRS and MRSI data acquisition.

The invention provides a breast tumor diagnosis system based on magnetic resonance spectrum imaging, comprising a superconduction MR (Magneto Resistance) scanner and a computer system. Through a computer auxiliary detection measure, the breast tumor diagnosis system realizes the early identification diagnosis of a breast tumor and the further diagnosis of breast cancer. Mammary gland magnetic resonance spectrum data are studied by adopting a distinctive manifold study method and projected to a low dimension embedding space, thus not only a low dimension manifold structure hidden in a high dimension magnetic resonance spectrum space can be revealed, but also the identification information in the mammary gland magnetic resonance spectrum data can be efficiently kept; then optimization clustering is carried out on the low dimension identification characteristic by utilizing a clustering method so that data points without the similar identification characteristic are separated to the maximum; and further a cost sensitive mechanism is introduced to achieve misclassification total cost minimization and realize optimization diagnosis of the breast cancer.

A new method is developed to accelerate high-resolution magnetic resonance spectroscopic imaging (MRSI). The method is built on a low-dimensional subspace model exploiting the partial separability of high-dimensional MRSI signals and uses this subspace model for data acquisition, processing, and image reconstruction. Specifically for two and three dimensional MRSI with one spectral dimension, this method sparsely samples the corresponding (k,t)-space in two complementary data sets, one with dense temporal sampling and high signal-to-noise ratio but limited k-space coverage and the other with sparse temporal sampling but extended k-space coverage. The reconstruction is then done by estimating a set of temporal/spectral basis functions and the corresponding spatial coefficients from these two data sets. The proposed subspace model can be further extended to incorporate multiple signal components for nuisance signal removal in ¹H-MRSI and more generalized reconstruction methods. The resulting imaging technique can be used for high-resolution MRSI of different nuclei. It will be useful for high-resolution metabolic imaging with many exciting applications.

A method of performing spatially localized magnetic resonance spectroscopy includes receiving a magnetic resonance image of an object; identifying a plurality C of compartments that generate magnetic resonance spectroscopy signals in the object including at least one compartment of interest; segmenting in at least one spatial dimension the magnetic resonance image of the object into the C compartments; acquiring magnetic resonance spectroscopy signals from the compartments by applying a plurality of M′ phase encodings applied in the at least one spatial dimension, wherein M′≧C; calculating a spatially localized magnetic resonance chemical shift spectrum from the at least one compartment of interest; and rendering a spatially localized magnetic resonance spectrum that is substantially equal to a spatial average of magnetic resonance chemical shift spectra from the at least one compartment of interest. A magnetic resonance spectroscopy and imaging system is configured to perform the above method.

A method and system for providing a fast image reconstruction of magnetic resonance spectroscopic imaging (MRSI) data based on applying, at least in part, interferometric techniques using a single receiver element. The images are reconstructed through temporally cross-correlating spacially incoherent k-space locations.

A new method is developed for ultrafast, high-resolution magnetic resonance spectroscopic imaging (MRSI) using learned spectral features. The method uses Free Induction Decay (FID) based ultrashort-TE and short-TR acquisition without any solvent suppression pulses to generate the desired spatiospectral encodings. The spectral features for the desired molecules are learned from specifically designed “training” data by taking into account the resonance structure of each compound generated by quantum mechanical simulations. A union-of-subspaces model that incorporates the learned spectral features is used to effectively separate the unsuppressed water/lipid signals, the metabolite signals, and the macromolecule signals. The unsuppressed water spectroscopic signals in the data can be used for various purposes, e.g., removing the need of additional auxiliary scans for calibration, and for generating high quality quantitative tissue susceptiability mapping etc. Simultaneous spatiospectral reconstructions of water, lipids, metabolite and macromolecule can be obtained using a single ¹H-MRSI scan.

The invention discloses a fat pressing method for magnetic resonance spectrum imaging. The fat pressing method comprises the following steps of: acquiring non-fat-pressing spectrum imaging data: acquiring the non-fat-pressing spectrum imaging data by adopting a CSI (Channel State Information) sequence; preprocessing the data: preprocessing the non-fat-pressing wave spectrum imaging data to obtain data XCSI; preparing masks: preparing a lipid signal mask MIipid and a metabolite signal mask Mtrain; performing double-weight signal reconstruction to obtain a double-weight signal Xdual; and performing L2 constraint reconstruction to obtain metabolite spectrum signals X with lipid signals removed. The data acquisition sequence adopted by the method is a clinical common sequence and does not need to be acquired for multiple times, so that the data acquisition time is short; lots of prior information is not needed; and lipid signals can be quickly and robustly removed, and metabolite signals can be retained.