Patent classifications
G01R33/4616
Method for measuring NMR-data of a target sample in an NMR spectrometer and NMR spectrometer
An NMR spectrometer includes a compensation system comprising at least one target sample coil and a lock sample coil positioned in a volume of interest between the main magnet poles of a main field magnet that generate a main magnetic field, at least one compensation coil for compensating a drift of the main magnetic field within the volume of interest, at least one target channel for generating RF-pulses with a target excitation frequency, and a lock data treatment system comprising a lock channel for generating RF-pulses with a lock excitation frequency, the lock data treatment system adapting a compensation current in the at least one compensation coil and correcting simultaneously the target frequency by applying a target frequency correction offset at the target channel. The spectrometer lock channel is improved, particularly for measurements where the lock coil and the target coil are positioned separately within the volume of interest.
Methods and apparatus for scan time reductions in magnetic resonance imaging using outer volume supression
Methods for fast magnetic resonance imaging (MRI) using a combination of outer volume suppression (OVS) and accelerated imaging, which may include simultaneous multislice (SMS) imaging, data acquisitions amenable to compressed sensing reconstructions, or combinations thereof. The methods described here do not introduce fold-over artifacts that are otherwise common to reduced field-of-view (FOV) techniques.
Readout-segmented diffusion-weighted imaging method, apparatus, and storage medium
In a magnetic resonance readout-segmented diffusion-weighted imaging method, apparatus, and storage medium, a non-linear phase RF excitation pulse is applied to nuclear spins that exhibit a magnetization intensity vector, and applying, in a slice selection direction, a slice selection gradient pulse of duration corresponding to the non-linear phase RF excitation pulse, so as to flip the magnetization intensity vector into the X-Y plane. Diffusion weighting is performed on the magnetization intensity vector flipped into the X-Y plane. A readout-segmented sampling sequence is executed to read out raw data in a segmented manner from the magnetization intensity vector resulting from diffusion weighting. A view angle tilting gradient pulse is applied in the slice selection direction.
Methods of constructing and designing RF pulses and exciting or inverting two-level systems
The present disclosure provides for a method of designing a radiofrequency or broadband pulse sequence. The method can comprise a qubit (e.g., nuclear spin, photon, electron, atomic spin, dot spin) and a harmonic oscillator wherein a flip angle is controlled by steering a spring between specific states.
METHODS OF DETERMINING PROTEIN OR PEPTIDE CONCENTRATION AND USES THEREOF
Methods for determining protein and/or peptide concentration or molecular parameter, such as the extinction coefficient, and uses thereof.
METHOD AND DEVICE FOR MAGNETIC RESONANCE IMAGING, AND CORRESPONDING COMPUTER PROGRAM PRODUCT
In a Method and a device for magnetic resonance imaging of a subject using a spoiled gradient echo sequence, a B.sub.0 magnetic field strength of at most 1.5 T is used during the sequence. As part of the sequence a slice select gradient acting as a spoil gradient is played out. Substantially simultaneously with the slice select gradient a predetermined RF pulse is played out in the sequence, wherein a time-bandwidth product of the RF pulse is set so that a majority of the energy of the RF pulse is transmitted in its central main lobe.
PH-weighted MRI using fast amine chemical exchange saturation transfer (CEST) imaging
A pH-weighted chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) method and system are provided that works by indirectly measuring the NMR signal from amine protons found on the backbones of amino acids and other metabolites, which resonate at a frequency of +2.8-3.2 ppm with respect to bulk water protons. The technique uses a modified magnetization transfer radiofrequency saturation pulse for the generation of image contrast. A train of three 100 ms Gaussian pulses at high amplitude (6 uT) or Sinc3 pulses are played at a particular frequency off-resonance from bulk water prior to a fast echo planar imaging (EPI) readout, with one full image acquired at each offset frequency. This non-invasive pH-weighted MRI technique does not require exogenous contrast agents and can be used in preclinical investigations and clinical monitoring in patients with malignant glioma, stroke, and other ailments.
Methods for determining plant rubber content with low field NMR
Methods are described for quantifying an amount of natural rubber in a plant from a sample of the plant by obtaining a NMR spectrum and analyzing the signal peaks for the natural rubber in the plant sample and a standard component tested in combination with the plant sample. The NMR testing is conducted on a liquid state sample of a solution containing dissolved plant sample and standard component. A pre-determined and known amount of standard component is present in the liquid state sample and provides a reference for calculating an estimated amount of natural rubber in the plant sample. The estimated amount of natural rubber in the sample can be used to quantify the amount of extractable rubber in the sampled plant.
PH-WEIGHTED MRI USING FAST AMINE CHEMICAL EXCHANGE SATURATION TRANSFER (CEST) IMAGING
A pH-weighted chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) method and system are provided that works by indirectly measuring the NMR signal from amine protons found on the backbones of amino acids and other metabolites, which resonate at a frequency of +2.8-3.2 ppm with respect to bulk water protons. The technique uses a modified magnetization transfer radiofrequency saturation pulse for the generation of image contrast. A train of three 100 ms Gaussian pulses at high amplitude (6 uT) or Sinc3 pulses are played at a particular frequency off-resonance from bulk water prior to a fast echo planar imaging (EPI) readout, with one full image acquired at each offset frequency. This non-invasive pH-weighted MRI technique does not require exogenous contrast agents and can be used in preclinical investigations and clinical monitoring in patients with malignant glioma, stroke, and other ailments.
Apparatus and method for spatial encoding using a radio frequency signal in magnetic resonance tomography
An apparatus and a method for spatial encoding in magnetic resonance tomography using a radio frequency signal are provided. A first set of parameters from a first frequency and from a first amplitude, and from a second frequency and a second amplitude is determined by the magnetic resonance tomograph, and corresponding signals are generated by a radio frequency device and transmitted by an antenna apparatus. A first gradient above the Larmor frequency of the nuclear spins is generated by the Bloch-Siegert effect. The same thing ensues with a second set of parameters that differs from the first set of parameters at least in one frequency or amplitude and therefore generates a second, different gradient.