188 results about "Magnetic resonance spectrometry" patented technology

An antenna (100), which is designed for exciting and/or detecting a magnetic resonance in an object (1) under investigation, comprises a conductor loop (10) with an inner conductor (11) and a primary shield conductor (12), which form at least one waveguide, wherein the primary shield conductor (12) is interrupted by a gap (13), and wherein a secondary shield conductor (14) is provided which surrounds the primary shield conductor (12), wherein a dielectric (15) is arranged between the primary shield conductor (12) and the secondary shield conductor (14) and at least the gap is covered by the secondary shield conductor (14). An antenna arrangement which comprises a plurality of such antennas, a magnetic resonance device, and a method for magnetic resonance imaging or magnetic resonance spectroscopy are also described.

A system and method for automating an appropriate voxel prescription in a uniquely definable region of interest (ROI) in a tissue of a patient is provided, such as for purpose of conducting magnetic resonance spectroscopy (MRS) in the ROI. The dimensions and coordinates of a single three dimensional rectilinear volume (voxel) within a single region of interest (ROI) are automatically identified. This is done, in some embodiments by: (1) applying statistically identified ROI search areas within a field of view (FOV); (2) image processing an MRI image to smooth the background and enhance a particular structure useful to define the ROI; (3) identifying a population of pixels that define the particular structure; (4) performing a statistical analysis of the pixel population to fit a 2D model such as an ellipsoid to the population and subsequently fit a rectilinear shape within the model; (5) repetiting elements (1) through (4) using multiple images that encompass the 3D ROI to create a 3D rectilinear shape; (6) a repetition of elements (1) through (5) for multiple ROIs with a common FOV. A manual interface may also be provided, allowing for override to replace by manual prescription, assistance to identify structures (e.g. clicking on disc levels), or modifying the automated voxel (e.g. modify location, shape, or one or more dimensions).

Methods and apparatuses for magnetic resonance imaging (MRI) and/or magnetic resonance spectroscopy comprising a superconducting main magnet operable to generate a uniform magnetic field in an examination region, at least one superconducting gradient field coil operable to apply a respective at least one magnetic field gradient within the examination region, and at least one RF coil that is operable to transmit and receive radio frequency signals to and from the examination region, and that is configured for cooling and comprises at least one of (i) a non-superconducting material that when cooled to a temperature below room temperature has a conductivity higher than that of copper at that temperature and (ii) a superconducting material. The main magnet, the gradient coils, and each of the at least one RF coil of a given system may each be implemented as high temperature superconductor materials.

The present invention provides a new approach for cancer treatment by utilizing gene therapy combined with radiation therapy to enhance cytotoxicity in malignant cells. Specifically, the present invention demonstrates that molecular chemotherapy with the cytosine deaminase gene and 5-fluorocytosine is an effective radiosensitizing strategy which may lead to substantial improvement in tumor control, with less normal tissue toxicity than conventional systemic administration of 5-fluorouracil, that would translate into improved cure rates and better survival. A noninvasive method is described for continuous in vivo monitoring of 5-fluorouracil production via magnetic resonance spectroscopy. An adenovirus encoding cytosine deaminase gene which selectively replicates in tumor cells with a defective p53 pathway was constructed. Also provided is an adenovirus which encodes a fusion protein of cytosine deaminase and uracil phosphoribosyltransferase.

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.

An antenna (100) for a magnetic resonance device has a predetermined sensitivity and is designed to excite and/or detect a magnetic resonance in an object under test. The antenna (100) includes a stripline resonator (10) that is equipped with at least one stripline (11), and a conductor loop arrangement (20) that adjoins the stripline resonator (10) and forms at least one conductor loop (21, 22, 28) which is interrupted by at least one capacitor (23). The sensitivity of the antenna (100) is formed by overlapping sensitivity profiles of the stripline resonator (10) and the conductor loop arrangement (20). Also described are an antenna array (200) including a plurality of antennas (100), a magnetic resonance device (300) including at least one antenna (100) or antenna array (200), and methods for magnetic resonance imaging or magnetic resonance spectroscopy.

The invention provides a method for obtaining a high-resolution two-dimensional J decomposition spectrum, and relates to a nuclear magnetic resonance spectroscopy detection method. The method comprises: loading a sample to be detected into a standard nuclear magnetic test tube, and conveying into the detection chamber of a nuclear magnetic resonance spectrometer; sampling the one-dimensional hydrogen spectrum of the sample to be detected, and obtaining the signal peak distribution area and the spectral line width so as to provide the reference for the spectral width parameter setting, wherein the line width value reflects the magnetic field uniformity condition; measuring the pulse width of a radio frequency pulse required by excitation of the sample to be detected; introducing a compiled pulse sequence on the nuclear magnetic resonance spectrometer, opening the heteronuclear intermolecule multiple quantum coherent signal excitation module, the indirect dimensional evolving module, the spin echo fixed delay module and the J modulating fast sampling module of the pulse sequence, and setting the experiment parameters of various modules; skipping the artificial shimming operation process, and directly executing data sampling; and after completing the data sampling, calling data post-processing codes to carry out related data post-processing so as to obtain the high-resolution two-dimensional J decomposition spectrum being not affected by the inhomogeneous magnetic field.

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.

A method for magnetic resonance spectroscopy (=MRS) or magnetic resonance imaging (=MRI) in which an NMR time-domain signal is created by an RF excitation pulse applied to an object in the presence of an applied magnetic field that may depend on spatial position and/or time, the time-domain signal being generated by an excited transverse nuclear magnetisation precessing about the applied magnetic field, whereby the RF excitation pulse is adapted to cover a whole range of NMR frequencies of interest present in the object, and time-domain signal acquisition takes place during, or during and after the application of the RF excitation pulse, is characterized in that spectral or image data are reconstructed by a matrix product of a reconstruction matrix and a vector of time-domain signal points, the reconstruction matrix being an inversion of an encoding matrix A_nα whose elements are calculated using the formula:

wherein n is the running number of a time-domain signal point, α is the running number of a discrete image or spectral element, P_m is the m-th discrete element of the RF excitation pulse in the time-domain, and Φ(n,m,α) is the phase accrued by the transverse nuclear magnetisation related to the discrete image or spectral element a in the time between the discrete RF excitation pulse element P_m and the time-domain signal point n under the influence of the applied magnetic field. An improved method for reconstructing spectral or image data from time-domain signal acquired as describe above is thereby provided which can be used more versatilely than conventional Fourier transform.

A method for obtaining a nuclear magnetic resonance two-dimension spin echo related spectrum under an uneven magnetic field relates to a nuclear magnetic resonance wave spectrum detection method and comprises the steps of using a normal one-dimension pulse sequence to sample a one-dimension spectrum, obtaining the line width of spectral lines, and providing a basis for spectrum width parameter setting, wherein the line width value also reflects the uniformity condition of a magnetic field; introducing well precompiled two-dimension spin echo related spectrum pulse sequences onto a nuclear magnetic resonance spectrometer; opening a multi-quantum coherent signal selection module, a three-dimension sampled indirect dimension evolution period t1 combination and indirect dimension evolution period t2 combination and an echo delay module among the two-dimension spin echo related spectrum pulse sequences; setting each experiment parameter of the two-dimension spin echo related spectrum pulse sequences; executing the two-dimension spin echo related spectrum pulse sequences, of which the experiment parameters are set, for data sampling; after the data sampling is finished, performing related data postprocessing to obtain the two-dimension spin echo related spectrum uninfluenced by the uneven magnetic field. The method has no need of shimming operation and is simple, convenient and effective.

A method for classifying a possible cancer from a magnetic resonance spectrographic (MRS) dataset includes extracting at least one feature from the MRS dataset as being identified with the possible cancer and embedding the extracted feature into a low dimensional space to form an embedded space. The method then clusters the embedded space into clusters representing a plurality of predetermined classes and spectrally decomposing the clusters to identify substantially significant independent metabolic signatures. The method then classifies the possible cancer as belong to one of at least two cancer classes based on the identified independent metabolic signatures.

In a method for evaluating data of a magnetic resonance signal, a baseline is modeled and at least one metabolite signal is modeled. The modeling of the baseline ensues based on magnetic resonance data in the time domain, and using only data that begins with the magnetic resonance signal and having a length that is shorter than the duration of the overall magnetic resonance signal.

Layers or coats of materials with high dielectric constant or permittivity with very low conductivity are inserted in between radiofrequency (RF) coil or coil's conductive elements and the sample to enhance the signal to noise ratio (SNR), improve image contrast, and reduce the specific absorption rate (SAR) of magnetic resonance imaging or magnetic resonance spectroscopy instruments. The embodiments of the present invention can be used as an auxiliary device to the standard pre-constructed RF coils or incorporated with RF coil constructions for enhancing RF coil performances in both transmission and reception.

A persistent-mode magnet, assembled from superconducting annuli, provides a micro coil NMR, in which compactness and manufacturability are provided for a variety of applications. An annular magnet for micro NMR can include a YBCO-annulus Helmholtz coil, for example, that can energized by a magnet system and then transported for use at a second location with an operating system.

A method is provided for producing, with a magnetic resonance (MR) system, a nuclear magnetic resonance spectrum that has been corrected for errors arising from phase offsets and time shifts in the acquired spectroscopic data. A spectroscopic data set includes temporal information indicative of the underlying phase offsets and time shifts. In general, this temporal information is utilized to correct for errors in the acquired data. As a result, a plurality of acquired spectroscopic data sets are more accurately combined by first individually correcting each spectroscopic data set for such errors. Exemplary sources of the phase offsets and time shifts include the physical separation between a volume of interest and the detectors in the MRI system. Using the temporal information, T₂ decay in the produced spectrum is also corrected.

Systems and methods are provided for processing a set of multiple serially acquired magnetic resonance spectroscopy (MRS) free induction decay (FID) frames from a multi-frame MRS acquisition series from a region of interest (ROI) in a subject, and for providing a post-processed MRS spectrum. Processing parameters are dynamically varied while measuring results to determine the optimal post-processed results. Spectral regions opposite water from chemical regions of interest are evaluated and used in at least one processing operation. Frequency shift error is estimated via spectral correlation between free induction decay (FID) frames and a reference spectrum. Multiple groups of FID frames within the acquired set are identified to different phases corresponding with a phase step cycle of the acquisition. Baseline correction is also performed via rank order filter (ROF) estimate and a polynomial fit. Sections of the ROF may be excluded from the polynomial fit, such as for example sections determined to be associated with relevant spectral peaks.

The invention discloses a two-dimensional diffusion-ordered nuclear magnetic resonance spectroscopy method used for any magnetic field environments and relates to nuclear magnetic resonance spectroscopy detection methods. The method includes the steps of 1), measuring pi/2 nonselective radiofrequency pulse width and (pi/2) solvent selective radiofrequency pulse width required by sample stimulation; 2), importing a nuclear magnetic resonance pulse sequence on a nuclear magnetic resonance spectrometer; 3), turning on an intermolecular zero-quantum coherence signal selection module, a time-invariant evolution module and a diffusion order module of the nuclear magnetic resonance pulse sequence and setting experiment parameters of all modules; 4), executing data sampling; 5), performing data post-processing to obtain high-resolution two-dimensional diffusion-ordered spectroscopy. The two-dimensional diffusion-ordered nuclear magnetic resonance spectroscopy method used for any magnetic field environments does not need any shimming operation, a sample preprocessing process and any special hardware devices, is simple, convenient and feasible and is applicable to any conventional nuclear magnetic resonance spectrometers.