G01R33/4616

Mas stator of an NMR probe head with optimized microwave irradiation
10197653 · 2019-02-05 · ·

An NMR probe head with an MAS stator (1) supplied with microwave radiation from a microwave guide (9) through an opening in a coil block (2) has a microwave lens (6) and a microwave mirror (8a) on an inner side of the MAS stator. The MAS rotor (3) is surrounded by a solenoid RF coil (5) and the microwave lens is arranged and embodied in the opening of the coil block on the side facing a sample volume (4) such that the cylinder axis of the MAS rotor lies in the focus of the microwave lens. The microwave mirror is arranged on, or in, the inner wall of the MAS stator that lies opposite the microwave guide and has a cylindrical and concave structure, such that the microwave mirror focuses the microwave radiation incident from the sample volume onto the central axis of the MAS rotor.

METHODS OF CONSTRUCTING AND DESIGNING RF PULSES AND EXCITING OR INVERTING TWO-LEVEL SYSTEMS
20180365584 · 2018-12-20 · ·

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.

MAGNETIC RESONANCE IMAGING (MRI) SYSTEM AND METHOD INTEGRATING MULTI-NUCLIDE SYNCHRONOUS IMAGING AND SPECTRAL IMAGING

A magnetic resonance imaging (MRI) system and method integrating multi-nuclide synchronous imaging and spectral imaging is provided. The MRI system includes a spectral imaging module, a multi-nuclide synchronous imaging module, and a spectral reconstruction and image fusion module, where the spectral imaging module is configured to acquire a spectrum of a nuclide Nuc; the multi-nuclide synchronous imaging module is configured to perform synchronous imaging of nuclides Nuc1 . . . . Nucn, where when n=1, Nucl is .sup.1H; and when n>1, Nucn is a non-.sup.1H nuclide; and the spectral reconstruction and image fusion module is configured to receive the spectrum of the nuclide Nuc and images of the nuclides Nuc1 . . . . Nucn, and acquire spatial distribution information of compounds of the nuclide Nuc and spatial distribution information of the non-.sup.1H nuclide through fusion. The system and method can synchronously acquire MR signals of different nuclides, and reconstruct and fuse non-.sup.1H nuclide images.

IMAGING SYSTEMS AND METHODS

An imaging method may include obtaining imaging data associated with a region of interest (ROI) of an object. The imaging data may correspond to a plurality of time-series images of the ROI. The imaging method may also include determining, based on the imaging data, a data set including a spatial basis and one or more temporal bases. The spatial basis may include spatial information of the imaging data. The one or more temporal bases may include temporal information of the imaging data. The imaging method may also include storing, in a storage medium, the spatial basis and the one or more temporal bases.

READOUT-SEGMENTED DIFFUSION-WEIGHTED IMAGING METHOD, APPARATUS, AND STORAGE MEDIUM
20180356487 · 2018-12-13 · ·

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.

Method of designing and generating pulses for magnetic resonance imaging

A method of designing a refocusing pulse or pulse train for Magnetic Resonance Imaging comprises the steps of: a) determining a phase-free performance criterion representative of a proximity between a rotation of nuclear spins induced by the pulse and a target operator, summed or averaged over one or more voxels of an imaging region of interest; and b) adjusting a plurality of control parameters of the pulse to maximize the phase-free performance criterion; wherein each target operator is chosen so the phase-free performance criterion takes a maximum value when the nuclear spins within all voxels undergo a rotation of a same angle around a rotation axis lying in a plane perpendicular to a magnetization field B.sub.0, called a transverse plane, with an arbitrary orientation; wherein the angle is different from M radians, with integer M, preferably with < radians and even preferably with 0.9.Math. radians.

PHASE CYCLED MAGNETIC RESONANCE SPECTROSCOPE IMAGING
20180329007 · 2018-11-15 ·

Systems, methods, and other embodiments associated with phase cycled magnetic resonance spectroscopic imaging (PCSI). According to one embodiment, a method includes applying an excitation radio frequency (RF) pulse having a low flip angle to a sample. The method further includes adjusting the phase of the RF to sweep through a frequency range based, at least in part, on PCSI. Sampling is then performed in the frequency range. The method also includes receiving a set of data based, at least in part, on the sampling in the frequency range.

Magnetic resonance spectroscopy with phase rotation

In a method and magnetic resonance (MR) apparatus for acquiring an MR signal from an examination subject according to a pulse sequence, a first radio-frequency pulse is applied with a first phase and a gradient field is simultaneously applied in a first direction. Second and third radio-frequency pulses, with second and third phases, respectively, are applied simultaneously with a gradient field in a second direction. A fourth and a fifth radio-frequency pulse, with a fourth and a fifth phase, respectively, are applied and simultaneously with a gradient field in a third direction. A signal with a receiver phase is acquired =. The pulse sequence is repeated a number of times under phase rotation, wherein the third and fourth radio-frequency pulses in each repetition have the same phase, and the signals acquired in the repetition are added.

NUCLEAR MAGNETIC RESONANCE MICROPROBE DETECTORS AND METHOD FOR DETECTION OF LOW-VOLUME SAMPLES

NMR microprobe detectors and methodologies that provide enhanced signal sensitivity for low-volume sample detection and analysis are described. In one embodiment the microprobe detector is a flat wire detector with a strip conductor having a length and width and ratio greater than 5 with a substantially uniform surface positioned on a low loss substrate in contact with a sample holder having a generally thin wall or at least a thin portion near where the sample probing and analysis occur.

METHODS AND APPARATUS FOR SCAN TIME REDUCTIONS IN MAGNETIC RESONANCE IMAGING USING OUTER VOLUME SUPRESSION
20180292487 · 2018-10-11 ·

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.