Patent classifications
G01R33/3678
Circular polarization correction in nuclear magnetic resonance (NMR) logging
A method for nuclear magnetic resonance (NMR) logging is disclosed that pulses, using a quadrature antenna of an NMR logging tool in a borehole, a circularly polarized (CP) signal into a formation surrounding the borehole. The method also pulses, using the quadrature antenna, a reverse circularly polarized (RCP) signal into the formation. A sensor of the NMR logging tool detects a first NMR signal from the formation in response to the RCP pulses and a second NMR signal from the formation in response to the CP pulses. A correct transverse magnetization value is then recovered based, at least in part, on the first NMR signal and the second NMR signal.
Multi-planar intraoral RF coil for magnetic resonance imaging
A multi-planar intraoral radio frequency (RF) coil apparatus for use in a magnetic resonance imaging system can include a housing having a shape configured to be positioned in an occlusal plane between an upper jaw and a lower jaw of a subject and a plurality of coil elements disposed within the housing. The plurality of coil elements includes a first coil element positioned in a first plane and a second coil element positioned in a second plane different from the first plane and substantially parallel to the first plane. The coil elements can be loop coil elements or dipole coil elements.
METHOD OF IMAGING USING AZIMUTHALLY RESOLVED NMR WHILE DRILLING
A nuclear magnetic resonance (NMR) sensor and methods and systems for use are provided. The method comprises disposing a nuclear magnetic resonance (NMR) sensor into a borehole, the NMR sensor comprising a magnet assembly to create a static magnetic field and a first transversal-dipole antenna having an azimuthally selective response function. The method further comprises, while rotating the NMR sensor, initiating azimuthally selective NMR excitation in at least one sensitivity region at a first frequency using the first transversal-dipole antenna and the magnet assembly, wherein the at least one sensitivity region is determined by the static magnetic field and the RF magnetic field. The method then comprises acquiring one or more azimuthally selective NMR signals at the first frequency using the first transversal-dipole antenna.
Method and system for in-vivo, and non-invasive measurement of metabolite levels
Embodiments of a compact portable nuclear magnetic resonance (NMR) device are described which generally include a housing that provides a magnetic shield; an axisymmetric permanent magnet assembly in the housing and having a bore, a plurality of magnetic elements that together provide a well confined axisymmetric magnetization for generating a near-homogenous magnetic dipole field B.sub.0 directed along a longitudinal axis and providing a sample cavity for receiving a sample, and high magnetic permeability soft steel poles to improve field uniformity: a shimming assembly with coils disposed at the longitudinal axis for spatially correcting the near homogenous magnetic field B.sub.0; and a spectrometer having a control unit for measuring a metabolite in the sample by applying magnetic stimulus pulses to the sample, measuring free induction delay signals generated by an ensemble of hydrogen protons within the sample; and suppressing a water signal by using a dephasing gradient with frequency selective suppression.
Cervical vertebra angle measurement
This disclosure provides a method of measuring the axial rotation of a selected vertebra of a patient using a magnetic resonance (MR) image. The method includes: identifying, in the MR image, two or more features of the selected vertebra; determining a first axis connecting the identified features; identifying, in the MR image, two or more features of the patient's surrounding anatomy that are not features of the selected vertebra; determining a second axis connecting the identified features of the patient's surrounding anatomy; measuring the angular difference between the first and second axes; and determining the axial rotation of the cervical vertebra based on the measurement. In some examples of the disclosure, determining the axial rotation of the cervical vertebra is based on the degree of perpendicularity between the first and second axes.
Method and device for controlling a magnetic resonance imaging system
Techniques are described for controlling a magnetic resonance imaging system to facilitate an improvement in Simultaneous Multislice Imaging, especially concerning a compensation of eddy currents. This is achieved by simultaneously measuring at least two slices by the magnetic resonance imaging system while applying a pulse sequence. In the course of the pulse sequence for measuring k-space lines, a set of in-plane encoding signals (that are typically gradients) are applied with a set of Hadamard encoding signals in an interleaved scheme.
Magnetic resonance imaging apparatus and RF coil device
According to one embodiment, an MRI apparatus includes a power transmitting unit a signal receiving unit and an image reconstruction unit. The power transmitting unit wirelessly transmits electric power to an RF coil device by magnetically coupled resonant type wireless power transfer. The signal receiving unit wirelessly receives a digitized nuclear magnetic resonance signal wirelessly transmitted from the RF coil device. The image reconstruction unit obtains a nuclear magnetic resonance signal received by the signal receiving unit, and reconstructs image data of an object on the basis of the nuclear magnetic resonance signal.
METHOD AND SYSTEM FOR IN-VIVO, AND NON-INVASIVE MEASUREMENT OF METABOLITE LEVELS
Embodiments of a compact portable nuclear magnetic resonance (NMR) device are described which generally include a housing that provides a magnetic shield; an axisymmetric permanent magnet assembly in the housing and having a bore, a plurality of magnetic elements that together provide a well confined axisymmetric magnetization for generating a near-homogenous magnetic dipole field B.sub.0 directed along a longitudinal axis and providing a sample cavity for receiving a sample, and high magnetic permeability soft steel poles to improve field uniformity: a shimming assembly with coils disposed at the longitudinal axis for spatially correcting the near homogenous magnetic field B.sub.0; and a spectrometer having a control unit for measuring a metabolite in the sample by applying magnetic stimulus pulses to the sample, measuring free induction delay signals generated by an ensemble of hydrogen protons within the sample; and suppressing a water signal by using a dephasing gradient with frequency selective suppression.
METHOD AND SYSTEM FOR IN-VIVO, AND NON-INVASIVE MEASUREMENT OF METABOLITE LEVELS
Embodiments of a compact portable nuclear magnetic resonance (NMR) device are described which generally include a housing that provides a magnetic shield; an axisymmetric permanent magnet assembly in the housing and having a bore, a plurality of magnetic elements that together provide a well confined axisymmetric magnetization for generating a near-homogenous magnetic dipole field B.sub.0 directed along a longitudinal axis and providing a sample cavity for receiving a sample, and high magnetic permeability soft steel poles to improve field uniformity: a shimming assembly with coils disposed at the longitudinal axis for spatially correcting the near homogenous magnetic field B.sub.0; and a spectrometer having a control unit for measuring a metabolite in the sample by applying magnetic stimulus pulses to the sample, measuring free induction delay signals generated by an ensemble of hydrogen protons within the sample; and suppressing a water signal by using a dephasing gradient with frequency selective suppression.
METHOD AND SYSTEM FOR IN-VIVO, AND NON-INVASIVE MEASUREMENT OF METABOLITE LEVELS
Embodiments of a compact portable nuclear magnetic resonance (NMR) device are described which generally include a housing that provides a magnetic shield; an axisymmetric permanent magnet assembly in the housing and having a bore, a plurality of magnetic elements that together provide a well confined axisymmetric magnetization for generating a near-homogenous magnetic dipole field Bo directed along a longitudinal axis and providing a sample cavity for receiving a sample, and high magnetic permeability soft steel poles to improve field uniformity: a shimming assembly with coils disposed at the longitudinal axis for spatially correcting the near homogenous magnetic field Bo; and a spectrometer having a control unit for measuring a metabolite in the sample by applying magnetic stimulus pulses to the sample, measuring free induction delay signals generated by an ensemble of hydrogen protons within the sample; and suppressing a water signal by using a dephasing gradient with frequency selective suppression.