The provided is a signal saturation method for achieving spatial selection under a non-uniform field, and a medium. The method includes: setting a corresponding magnetization preparation module based on a distance between a target saturation region and a surface coil under a non-uniform field (S1); transmitting, by the surface coil, a first main pulse sequence, or sequentially transmitting a first magnetization preparation module and a first main pulse sequence, to acquire a first echo signal, and storing the first echo signal as a first dataset (S2); sequentially transmitting, by the surface coil, a second magnetization preparation module and a second main pulse sequence to acquire a second echo signal, and storing the second echo signal as a second dataset (S3); and processing the first dataset and the second dataset to saturate a signal in the target saturation region, thereby achieving spatial selection (S4).
The provided is a magnetic resonance (MR) system and a method for measuring a regional body fat content using same. The method includes: when an object to be measured is a single-substance object: acquiring, by a corresponding radio frequency (RF) pulse sequence, an MR signal of the object to be measured; processing the acquired MR signal, and obtaining a target characteristic parameter value; calibrating, by phantoms with known different fat contents, the characteristic parameter, and establishing a correspondence between the characteristic parameter and the fat contents; and determining a fat content corresponding to the target characteristic parameter value (S1); and when the object to be measured is a mixed-substance object including a fat component and a non-fat component: acquiring an MR signal of the object to be measured; determining undetermined coefficients of the fat component and the non-fat component; and calculating a fat content of the object to be measured.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
A61B 5/00 - Measuring for diagnostic purposes Identification of persons
G01R 33/3415 - Constructional details, e.g. resonators comprising surface coils comprising arrays of sub-coils
G01R 33/36 - Electrical details, e.g. matching or coupling of the coil to the receiver
3.
Magnetic resonance system with spatial selectivity and working method thereof
The provided is a magnetic resonance (MR) system with spatial selectivity and a working method thereof. The MR system includes a data display and processing module, a spectrometer with at least one transmission channel, at least one power amplifier, a transmit-receive (TR) switch, a preamplifier, multiple sets of coils, and a magnet module, where when a number of transmission channels of the spectrometer is not less than a number of coils, one power amplifier is connected to the TR switch, while other power amplifiers are correspondingly connected to other coils (2, 3, 4) except for a main coil (1); when the number of the transmission channels of the spectrometer is less than the number of the coils, an output terminal of the at least one power amplifier is first connected to at least one power divider and multiple phase shifters and then connected to the coil.
Disclosed in the present invention are a rock sample measurement system and method with spatial selectivity. In the present invention, sampling signals of a rock sample at a plurality of angles can be acquired. Moreover, in the present invention, there is spatial selectivity during a rock sample measurement process, and a rock mass region without defects on the rock sample can be selected. Thus, by combining the sampling signals at the plurality of angles and the selected rock mass region, a real rock sample signal of the rock mass region without defects on the rock sample can be obtained. Finally, on the basis of the real rock sample signal, physical property parameters of the rock sample can be obtained. Thus, the present invention avoids the impact of rock sample surface defects on measurement signals, thereby obtaining a more accurate rock physical property parameter measurement result, and is suitable for large-scale application and popularization in the field of rock sample measurement.
G01N 24/08 - Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
G01R 33/38 - Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
5.
SIGNAL SATURATION METHOD FOR ACHIEVING SPATIAL SELECTION UNDER NON-UNIFORM FIELD, AND MEDIUM
A signal saturation method for achieving spatial selection under a non-uniform field, and a medium. The method comprises: under a non-uniform field, according to the distance between a region to be saturated and a surface coil, setting corresponding magnetization preparing modules (S1); transmitting by means of the surface coil a first main pulse sequence, or successively transmitting a first magnetization preparing module and the first main pulse sequence, so as to acquire a first echo signal and store same as a first data set (S2); successively transmitting by means of the surface coil a second magnetization preparing module and a second main pulse sequence, so as to acquire a second echo signal and store same as a second data set (S3); and processing the first data set and the second data set, so as to saturate a signal in said region, thus achieving spatial selection (S4). The method has the advantage of insensitivity to the non-uniformity of a main magnetic field, the intensity of a radio frequency field, the sizes of saturation regions, and position changes, and is more convenient in practical use, thus achieving a more stable and accurate signal saturation effect.
A magnetic resonance system having spatial selectivity and an operating method therefor. The system comprises a data display and processing module, a spectrometer provided with at least one transmitting channel, at least one power amplifier connected to the transmitting channel of the spectrometer in a one-to-one correspondence manner, a TR switch, a preamplifier, a plurality of coils, and a magnet module; when the number of the transmitting channels of the spectrometer is not less than the number of the coils, one power amplifier is connected to the TR switch, and other power amplifiers are correspondingly connected to coils (2, 3, 4) except a main coil (1); and when the number of the transmitting channels of the spectrometer is less than the number of the coils, an output end of the at least one power amplifier is connected to at least one power divider and a plurality of phase shifters and then is connected to the coils; and a radio frequency field and an excitation area generated by each coil are different, and the difference between the radio frequency field generated by the main coil (1) and the radio frequency fields generated by other coils (2, 3, 4) is greater than a preset value. The spatial selection of a target area signal can be realized without support of a gradient system, thereby reducing the costs and difficulty of magnetic resonance detection.
G01R 33/54 - Signal processing systems, e.g. using pulse sequences
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
7.
MAGNETIC RESONANCE SYSTEM, AND METHOD FOR USING SAME TO MEASURE BODY SURFACE FAT CONTENT
A magnetic resonance system, and a method for using same to measure a body surface fat content, the method comprising: when an object under examination is a single object, collecting, by using a corresponding radio-frequency pulse sequence, a magnetic resonance signal of said object for processing, so as to obtain a target feature parameter value, calibrating feature parameters by using known motifs having different fat contents, establishing correspondences between the feature parameters and the fat contents, and determining a fat content which corresponds to the target feature parameter value (S1); and when said object is a mixed object, treating said object as a mixture of a fat component and a non-fat component, collecting magnetic resonance signals of said object by using a radio-frequency pulse sequence, determining coefficients to be determined of the fat component and the non-fat component by using multi-parameter fitting, and calculating the fat content of said object according to said coefficients (S2). A calibration method for the fat content of a single object is provided, a parameter fitting method for the fat content of a mixed object is provided, and the measurement is accurate, thereby providing powerful data support for an examination performed by a magnetic resonance system.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
8.
Nuclear magnetic resonance (NMR) measurement system for non-invasive quantitative detection of organs
A comprehensive and integrated solution, including a dedicated system structure and grounding mechanism, a main radio frequency (RF) coil to transmit and receive signal, secondary RF coils to saturate unwanted signals from non-region-of-interest (ROI) in the excited region, an RF shielding structure configured to shield the main RF coil from generating signals on the non-ROI, and an environmental noise active cancellation mechanism is proposed to construct an NMR system for non-invasive quantitative detection of organs, and further improves the target region selectivity and detection accuracy.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
G01R 33/34 - Constructional details, e.g. resonators
G01R 33/565 - Correction of image distortions, e.g. due to magnetic field inhomogeneities
A61B 5/00 - Measuring for diagnostic purposes Identification of persons
9.
Nuclear magnetic resonance system-based substance measurement method and system
A nuclear magnetic resonance (NMR) system-based substance measurement method, including: acquiring several echo signals of an NMR pulse sequence varying in echo spacing from a substance to be measured followed by processing to obtain several signals varying in transverse relaxation and diffusion attenuation; and fitting, in combination with the prior knowledge, the signals to obtain the diffusion coefficient, transverse relaxation time or/and content weight of individual components of the substance to be measured. This application further provides a substance measurement system including a console, a magnet module, and an NMR system.
G01R 33/50 - NMR imaging systems based on the determination of relaxation times
G01R 33/56 - Image enhancement or correction, e.g. subtraction or averaging techniques
G01R 33/561 - Image enhancement or correction, e.g. subtraction or averaging techniques by reduction of the scanning time, i.e. fast acquiring systems, e.g. using echo-planar pulse sequences
G01R 33/563 - Image enhancement or correction, e.g. subtraction or averaging techniques of moving material, e.g. flow-contrast angiography
G01N 24/08 - Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
G01R 33/38 - Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
10.
Method for measuring the gradient field of a nuclear magnetic resonance (NMR) system based on the diffusion effect
A method for measuring a gradient field of a nuclear magnetic resonance (NMR) system based on a diffusion effect uses a non-uniform field magnet, an NMR spectrometer, a radio frequency (RF) power amplifier, an RF coil, and a standard quantitative phantom with known apparent diffusion coefficient (ADC) and time constant for decay of transverse magnetization after RF-pulse (T2). A plurality of sets of signals are acquired by an NMR sequence with different diffusion-sensitive gradient durations or different echo spacings and the magnitude of the gradient field is calculated by fitting based on the plurality of sets of signals. The method does not require an additional dedicated magnetic field detection device, has a short measurement time, is easy to use with the NMR system, and is convenient to complete gradient field measurement at the installation site, thereby improving the installation and service efficiency of the NMR system.
A method for non-invasive quantification of organ fat using a magnetic resonance approach includes: constructing a detection system; connecting a detection area; detection system startup; acquiring data; analyzing data; and performing horizontal data analysis. An external computer, a radio frequency (RF) subsystem, and a portable magnet module are used to construct a system for non-invasive quantification of organ fat based on low-field nuclear magnetic resonance (LF-NMR), which causes no damage, and achieves accurate and non-invasive quantification of organ fat. Specific pulse sequences are used to excite nuclear spin in a target region to generate LF-NMR, so as to achieve “one-click” detection, which is used for fast screening of related diseases such as non-alcoholic fatty liver disease (NAFLD). The system has accurate quantification, and is easy to operate without constraints of operator qualifications.
A61B 5/00 - Measuring for diagnostic purposes Identification of persons
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
G01R 33/34 - Constructional details, e.g. resonators
12.
NON-INVASIVE QUANTITATIVE NUCLEAR MAGNETIC RESONANCE DETECTION SYSTEM FOR ORGANS
The present invention relates to the technical field of nuclear magnetic resonance (NMR), and disclosed is a non-invasive quantitative NMR detection system for organs. The present invention may provide a novel NMR measurement system that may achieve the effect of regional selective excitation, that is, by arranging parallel radio frequency (RF) field shielding plates in a peripheral region of a main RF coil of an RF subsystem, some RF fields of the main RF coil may be shielded, so as to achieve the purpose of not exciting useless signals such as body surface fat, achieving the effect of regional selective excitation, and solving the problem of inaccurate fat detection due to unsatisfactory excitation regions being present in current unilateral magnet NMR systems.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
A61B 5/00 - Measuring for diagnostic purposes Identification of persons
13.
NUCLEAR MAGNETIC RESONANCE MEASUREMENT SYSTEM SUITABLE FOR NONINVASIVE QUANTITATIVE DETECTION OF ORGANS
A nuclear magnetic resonance measurement system suitable for noninvasive quantitative detection of organs. Provided is a nuclear magnetic resonance measurement system capable of achieving a regioselectivity excitation effect. Parallel secondary radio frequency coils (152) are arranged in a peripheral region of a main radio frequency coil (151) of a radio frequency subsystem, and before or during the transmission of a measurement sequence pulse signal, a pre-saturated pulse signal is transmitted by means of the secondary radio frequency coils (152) to generate a radio frequency field covering a region of non-interest within a detection region, such that some or all of magnetization vectors within the region of non-interest can be parallel to a static magnetic field generated by a magnet (2), and thus, an undesired signal that is generated in the region of non-interest and interferes with an echo signal generated in a region of interest can be weakened or disappear during the measurement, so as to achieve the regioselectivity excitation effect, and the problem of inaccurate fat detection caused by a current unilateral magnet nuclear magnetic resonance system due to the presence of a nonideal excitation region is solved.
G01R 33/54 - Signal processing systems, e.g. using pulse sequences
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
14.
ADC-T2 TWO-DIMENSIONAL SPECTRUM MEASUREMENT METHOD AND APPARATUS, COMPUTER DEVICE, AND NON-UNIFORM FIELD MAGNETIC RESONANCE SYSTEM
An ADC-T2 two-dimensional spectrum measurement method and apparatus, a computer device, and a non-uniform field magnetic resonance system, which can be used in a nuclear magnetic resonance system having an extremely non-uniform magnetic field or where extremely short echo time cannot be achieved. Multiple echo signals collected on the basis of CPMG sequences having different echo intervals are acquired, and ADC coefficients and T2 values are fitted from multiple sets of echo signals, such that an ADC-T2 spectrum can be measured, without using complex diffusion weighting sequences, thereby achieving the advantages of simple algorithm and low system requirements, and reducing the cost of hardware systems such as spectrometer devices, a radio frequency power amplifiers, and radio frequency coils. In addition, the measurement method also has the characteristics of stable algorithm, is not easy to be affected by flowing liquid, and is also suitable for substances having small T1/T2 values.
A multi-frequency coil, comprising a double-frequency implementation circuit (X1), a single-frequency implementation circuit (X2), and a coil body. The coil body comprises an input end and an output end. The coil body further comprises a butterfly-shaped coil and an annular coil. The double-frequency implementation circuit (X1) comprises a double-frequency input and output branch, a double-frequency frequency adjustment branch, a high-frequency adjustment branch, and a low-frequency adjustment branch. The double-frequency input and output branch and the double-frequency frequency adjustment branch are connected to the input end, and the high-frequency adjustment branch and the low-frequency adjustment branch are connected to the output end. The single-frequency implementation circuit (X2) comprises a single-frequency input and output branch, a grounding branch, and a single-frequency adjustment branch. The single-frequency input and output branch is connected to the input end, the grounding branch circuit is connected to the output end, and both ends of the single-frequency adjustment branch are connected to the input end and the output end, respectively. Three frequencies or four frequencies are realized using magnetic field direction characteristics of the two coils, thereby simplifying the decoupling of the coils, reducing the number of LC parallel resonators used, and effectively improving the transmitting efficiency and the receiving sensitivity of the coils.
A nuclear magnetic resonance system-based substance measurement method, and a system, used for solving or mitigating the technical problem in the prior art that the amount of data processed is large. The method comprises: acquiring several sets of nuclear magnetic resonance pulse sequence echo signals having different echo spacings from a measured substance, and processing same to obtain several sets of signals having transverse relaxation and diffusive attenuation; and fitting, in combination with the prior knowledge, the signals having transverse relaxation and diffusive attenuation to obtain the diffusion coefficient, transverse relaxation time or/and content weight of components of the measured substance. The system comprises: a console, a magnet module, and a nuclear magnetic resonance system. According to the measurement method and the system, by acquiring several sets of nuclear magnetic resonance pulse sequence echo signals having different echo spacings for fitting processing, the measurement of the diffusion coefficient, transverse relaxation time or/and content weight of the components of the measured substance can be achieved without acquiring a large amount of data.
G01N 24/08 - Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
17.
SHEAR WAVE ATTENUATION COEFFICIENT MEASUREMENT METHOD AND SYSTEM
A shear wave attenuation coefficient measurement method, comprising: applying a nuclear magnetic resonance pulse sequence to an object under test in a stable vibration state, and performing motion encoding in combination with a static or controllable gradient magnetic field, so as to detect nuclear magnetic resonance echo signals of at least two different positions of the object under test, and analyze and process the nuclear magnetic resonance echo signals to obtain a shear wave attenuation coefficient. A system comprises a magnetic resonance system, a mechanical vibration excitation apparatus and a nuclear magnetic resonance console. In the embodiment, an attenuation coefficient of a solid or a semisolid is measured in a non-invasive and non-destructive manner on the basis of low-field nuclear magnetic resonance. The problem of measurement failure caused by a certain medium being unable to be penetrated by means of an ultrasonic measurement method is solved.
G01H 11/02 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties by magnetic means, e.g. reluctance
Disclosed is a radial acquisition diffusion weighted imaging motion artifact correction method, comprising damaged data detection, damaged data repair, and filtered back projection reconstruction. The damaged data detection step comprises converting an original K-space data to a projection data space to obtain an original projection data set, reconstructing an original image from the original projection data set by filtered back projection, and then performing Radon transformation on the original image to obtain a new projection data set, and comparing the difference between the new projection data set and the original projection data set to detect motion damaged data. The damaged data repair comprises replacing the data of a damaged area with new projection data, and linearly fusing the data at the edge of the damaged area with the original projection data and the new projection data to obtain corrected projection data. Finally, a final image is reconstructed from the corrected projection data by means of filtered back projection reconstruction. The solution of the present invention can reduce motion artifacts, thus improving image quality.
Disclosed is a magnetic resonance system gradient field measurement method based on a diffusion effect, wherein a non-uniform field magnet, a nuclear magnetic resonance spectrometer, a radio-frequency power amplifier, a radio-frequency coil, a standard quantitative water model, the ADC coefficient and relaxation time constant T2 of which are known, etc. are involved. A plurality of groups of signals are collected by means of magnetic resonance sequences with different diffusion sensitive gradient durations or different echo spacings, and the magnitude of a gradient field is fitted from the plurality of groups of signals. The method does not require an additional special magnetic field detection device, enables a measurement time to be short, and can be easily integrated into a magnetic resonance system, such that the measurement of a gradient field can be easily and rapidly completed on an installation site, and the installation and service efficiency can be improved.
G01R 33/24 - Arrangements or instruments for measuring magnetic variables involving magnetic resonance for measuring direction or magnitude of magnetic fields or magnetic flux
20.
NON-UNIFORM FIELD MAGNETIC RESONANCE SYSTEM-BASED APPARENT DIFFUSION COEFFICIENT MEASURMENT METHOD
A non-uniform field magnetic resonance system-based apparent diffusion coefficient measurement method, which is based on a non-uniform field nuclear magnetic resonance system, comprising a non-uniform field magnet, a nuclear magnetic resonance spectrometer, a radio frequency power amplifier, a radio frequency coil and so on. Signals are collected by means of a plurality of CPMG sequences provided with different echo intervals, and an ADC coefficient is fitted from multiple sets of signals. The method does not require a complex diffusion enhancement sequence, and the algorithm is simple. Moreover, system requirements are low, and system costs may be reduced. At the same time, the algorithm of the method is stable and not easily affected by flowing liquid, and is also suitable for substances that have small T1/T2.
G01N 24/08 - Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
G01N 13/00 - Investigating surface or boundary effects, e.g. wetting powerInvestigating diffusion effectsAnalysing materials by determining surface, boundary, or diffusion effects
patents
