182results about "Measurements using NMR imaging systems" patented technology

A system for generating contrast-enhanced magnetic resonance images of a subject includes an input configured to receive at least one non-contrast enhanced image of the subject, and a contrast-enhanced magnetic resonance (MR) image synthesis neural network coupled to the input and configured to generate a contrast-enhanced magnetic resonance image of the subject based on the at least one non-contrast enhanced image of the subject. The contrast-enhanced MR image synthesis neural network is trained using a set of training data comprising at least quantitative data.

Disclosed herein is a method of magnetic resonance imaging. The method comprises receiving (200) groups of k-space data descriptive. The groups of k-space data comprise group specific imaging k- space data and group specific navigator k-space data. The method further comprises determining (202) group specific subject positions using the group specific navigator k-space data of the groups of k- space data. The method further comprises initializing (204) group specific motion parameters of a joint optimization using the group specific subject positions. The method further comprises reconstructing (206) a motion corrected magnetic resonance image by performing the joint optimization on the group specific imaging k-space data of the groups of k-space data. The joint optimization is configured to simultaneously reconstruct the motion corrected magnetic resonance image while determining the group specific motion parameters. The method further comprises providing (208) the motion corrected magnetic resonance image descriptive of the field of view.

The invention relates to a method for correcting the influence of interfering effects on a gradient system of a magnetic resonance device during a magnetic resonance measurement, having the following steps: emitting a gradient pulse by means of an amplifier of the gradient system; detecting a gradient profile; detecting an output signal of the amplifier for the gradient pulse; determining a gradient system transfer function; and determining an output signal of the amplifier, which provides the desired gradient profile at the output signal. The invention also relates to a correction device, which is designed to adjust an input signal of the amplifier in accordance with the determined output signal of the amplifier and the detected output signal of the amplifier. Furthermore, the invention relates to a magnetic resonance device and a magnetic resonance system having the correction device, as well as a computer program product having a computer program and a computer-readable medium for carrying out the method according to the invention.

Disclosed are methods for quantification of a perivascular space in a subject's central nervous system. The methods include administering contrast agent into cerebrospinal fluid of the subject; performing quantitative ultra-short time-to-echo contrast-enhanced magnetic resonance imaging (QUTE-CE MRI) on a region of interest of the subject's brain; and determining presence of the contrast agent in the perivascular space within the region of interest.

The present disclosure provides methods and systems for MRI. The method may include obtaining MRI data of a target subject. The MRI data may be collected by applying an MRI pulse sequence on the target subject. The MRI pulse sequence may include a monomial RF pulse for exciting first substance in the target subject and suppressing second substance in the target subject. The method may further include reconstructing a magnetic resonance (MR) image of the target subject based on the MRI data.

This document discloses a medical system including a memory (110) storing machine-executable instructions (120) and a trained neural network (122). The trained neural network is configured to output rectified magnetic resonance image data (130) in response to receiving a set of magnetic resonance images (126) as input, each of the magnetic resonance images in the set having a different spatially constant frequency deviation resonance factor. The medical system also includes a computing system (106) configured to control the medical system, wherein the execution of the machine-executable instructions causes the computing system to: receive (200) k-space data (124) acquired according to a magnetic resonance imaging protocol; reconstruct (202) a set of magnetic resonance images (126) according to the magnetic resonance imaging protocol, wherein each of the magnetic resonance images in the set of magnetic resonance images is reconstructed assuming different spatially constant frequency deviation resonance factors selected from a list of frequency deviation resonance factors (128); and receive (204) rectified magnetic resonance image data in response to inputting the set of magnetic resonance images into the trained neural network.

The present application relates to the technical field of nuclear magnetic resonance analysis, and particularly relates to a magnetic resonance signal three-dimensional spectrum feature recognition and analysis method.The method comprises the following steps: acquiring a multi-channel time-domain magnetic field signal sequence through a three-dimensional sensing array; performing frame windowing processing and fast Fourier transform on the sequence to construct a complex spectrum matrix; decoupling the matrix in the complex domain by using a statistical independence criterion, eliminating the arrangement ambiguity introduced by the frequency domain transform through sub-band division, component extraction and spatial response consistency judgment, and restoring to obtain independent spectrum component signals corresponding to different radiation source regions; calculating the physical center coordinates of each radiation source region in combination with the array spatial coordinates, and then constructing a three-dimensional spectrum feature fingerprint of space-frequency domain fusion; and finally recognizing the state feature of the to-be-tested subject according to the matching deviation degree of the fingerprint and the standard feature library.The present application solves the problems of multi-source magnetic signal space coupling and frequency domain stripping, and improves the accuracy of weak feature recognition.

A method for separately quantifying N-acetylcysteine and glutathione in brain tissue includes administering N-acetylcysteine to a subject, acquiring a first magnetic resonance spectroscopy signal from a region of brain tissue of the subject, the first magnetic resonance spectroscopy signal comprising a cysteine β-proton signal, acquiring a second magnetic resonance spectroscopy signal from the region of brain tissue, the second magnetic resonance spectroscopy signal comprising an N-acetyl proton signal, and determining a concentration of N-acetylcysteine in the region of brain tissue based on the N-acetyl proton signal and determining a concentration of glutathione in the region of brain tissue based on a difference between the cysteine β-proton signal and the N-acetyl proton signal.

The application relates to a magnetic resonance imaging method, device, computer equipment, storage medium and computer program product. The method comprises the following steps: in a first cardiac cycle, a characteristic electrocardio signal of a detection object is identified, a first sequence pulse is applied to the detection object after a preset delay time of identifying the characteristic electrocardio signal, and the first sequence pulse is used for reversing a longitudinal magnetization vector of the detection object; after the first sequence pulse is applied, a second sequence pulse of a target phase mode is applied to the detection object after a recovery time, and an initial cardiac imaging set is acquired, wherein the target phase mode is one of at least two different phase modes, and different target phase modes correspond to different positions of artifacts in the initial cardiac imaging sets; and the initial cardiac imaging sets obtained in each first cardiac cycle are subjected to first registration processing to obtain a cardiac imaging. The method can effectively weaken the artifacts in cardiac delayed enhancement imaging, and does not increase additional operations and additional scanning time.

Techniques for de-noising label-differenced medical images includes operating a medical scanner to collect a control image of a region of interest in a subject. The medical scanner is also operated to collect a labeled image of the region of interest. Multiple patches within the control image are selected. Each patch has a similarity better than a threshold compared to a co-located patch in the labeled image. A control low-rank variability model is derived for the patches within the control image to produce a de-noised control image. A labeled low-rank variability model is derived for the patches within the labeled image. A de-noised labeled image in the region of interest is produced based on the labeled low-rank variability model. A difference image in the region of interest is output based on a difference between the de-noised labeled image and the de-noised control image in the region of interest.

A radio frequency (RF) receiver assembly (100) for use in a magnetic resonance imaging (MRI) system is described. The receiver assembly (100) comprises a primary resonant circuit (101) coupled to a preamplifier (106) via capacitive coupling, and a secondary resonance circuit (104) comprising of at least one inductor (104a) coupled between a first switch (103) and the capacitive coupling. The first switch (103) is circuited between the primary (101) and the secondary (104) resonant circuits, and the preamplifier (106).

In one embodiment, an image processing apparatus comprising: a processing circuitry configured to: acquire an MR signal emitted from an object by an RF pulse of a first MRI apparatus being applied to the object; and generate an image based on the acquired MR signal, an MR signal corresponding to a period when a second MRI apparatus outputs an RF pulse, being not used for generating the image.

In a method for improving the recording of measurement data of an object under inspection, the method includes loading desired imaging parameters and a desired flip angle for recording the measurement data by means of a recording method, wherein the gradient to be switched for position encoding of the measurement data has its full intensity during the incident RF excitation pulse. A quantization value of a desired interference for the recording method is determined based on the desired imaging parameters, and a check on the feasibility of correcting for the interference is performed based on the quantization value and the desired flip angle.

The invention relates to a magnet device (11) for a magnetic resonance apparatus (10), the magnet device (11) comprising: a superconducting magnet (12); a discharge system (35); a switch (37) which is designed to interrupt a closed circuit in the superconducting magnet (12) and to transfer electrical energy which has accumulated in the superconducting magnet (12) to the discharge system (35); wherein the discharge system (35) comprises a supercapacitor (30) which is designed to buffer the electrical energy transport from the superconducting magnet (12) to the discharge element in the discharge system (35).

Provided is a deep learning based accelerated MRI image quality restoring method. The deep learning based accelerated MRI image quality restoring method includes extracting test information from an input accelerated MRI image, selecting at least one deep learning model corresponding to the test information, among a plurality of previously trained deep learning models, and outputting an MRI image with a restored image quality for the input accelerated MRI image with the input accelerated MRI image as an input of at least one selected deep learning model.

Methods and systems herein may perform nuclear magnetic resonance measurements, and nuclear magnetic resonance tools, the method and systems comprising: acquiring, using an NMR sensor a first NMR signal from a volume in a subterranean region, wherein the first NMR signal is acquired using a first acquisition window. Further, acquiring, using the NMR sensor a second NMR signal from a volume in the subterranean region, wherein the second NMR signal is acquired using a second acquisition window different from the first acquisition window, wherein the first NMR signal and the second NMR signal form an NMR relaxation data; determining, using the first NMR signal and the second NMR signal, a correction term. Finally, the correction term may be used to acquire a corrected relaxation data set.

Disclosed herein is a method of magnetic resonance imaging. The method comprises receiving (200) a sequence of magnetic resonance imaging scans (122) to be performed on a single examination subject (318) during a continuous time interval for a magnetic resonance imaging system (302). The method further comprises receiving (202) metadata (124) descriptive of the single examination subject and the magnetic resonance imaging system. The method further comprises receiving (204) a set of inter-scan time intervals (126) for time intervals between the sequence of magnetic resonance imaging scans in response to inputting the metadata and the sequence of magnetic resonance imaging scans into a trained artificial intelligence module (132). The set of inter-scan time intervals comprises: paired time intervals (128) and confidence levels (130) of the time intervals. The method further comprises providing (206) the set of inter-scan time intervals as control data for the magnetic resonance imaging system.

The application provides a real-time processing and analysis method for magnetic resonance scanning data, comprising: capturing the change process of intravascular contrast agent concentration and magnetic resonance signal intensity with time and the spatial distribution of magnetic field uniformity in real time, and identifying the signal attenuation amplitude and signal intensity decline rate caused by T2 star effect; for the determined arterial phase time starting point, combining the signal enhancement amplitude caused by T1 effect and the signal attenuation amplitude caused by T2 star effect, continuously monitoring the peak arrival time and peak duration in the signal intensity change process, and evaluating the optimal duration of the acquisition time window; according to the evaluated optimal duration of the acquisition time window, generating a trigger signal when the T1 effect is dominant and the T2 star effect has not yet significantly affected the signal intensity, activating the image acquisition of the scanning system, and obtaining pure arterial phase images.

A method for automatically determining an NMR pulse sequence for use in downhole NMR measurements, such as NMR logging while drilling measurements, includes receiving a set of expected NMR measurements and evaluating the received set of expected NMR measurements using a bilevel optimization to determine a pulse sequence for the downhole NMR measurement.

Provided herein is a noninvasive method for measuring pH, glucose and glycogen levels using a single acquisition method, as well as systems for performing the method. This method for glycogen / glucose (and pH) detection has high specificity enabled by superior chemical shift separation in high-strength magnetic fields. The methods have applications in detecting changing tumor microenvironments in cancerous cells for measuring important metrics for noninvasive and quantitative metabolic profiling.

A magnetic resonance system and a scanning method for a magnetic resonance system are provided. The method includes: acquiring a type of a radio frequency coupling coil; and on the basis of the type of the radio frequency coupling coil, determining a parameter for performing a magnetic resonance scan on a subject to be examined; the radio frequency coupling coil is positioned relative to the subject to be examined, and when positioned within a body coil of the magnetic resonance system, the radio frequency coupling coil is configured to generate electromagnetic coupling with the body coil to receive a radio frequency pulse from the body coil, so as to generate a radio frequency field for exciting the subject to be examined.

Embodiments of the present disclosure pertain to methods of detecting hypoxemia in a subject by: (1) receiving a blood sample from the subject; (2) measuring the T2 relaxation time constant of the blood cell (e.g., blood cell pellet) of the blood sample (T2P value); and (3) correlating the measured T2P value to hypoxemia. In some embodiments, the methods of the present disclosure also include a step of correlating the measured T2P value to the subject's susceptibility to one or more hypoxemia-related conditions. Further embodiments of the present disclosure pertain to systems for detecting hypoxemia in a subject in accordance with the methods of the present disclosure.

The present disclosure provides techniques for using opto-isolator circuitry to control switching circuitry configured to be coupled to a radio-frequency (RF) coil of a magnetic resonance imaging (MRI) system. In some embodiments, opto-isolator circuitry described herein may be configured to galvanically isolate switch controllers of the MRI system from the switching circuitry and / or provide feedback across an isolation barrier. Some embodiments provide an apparatus including switching circuitry configured to be coupled to an RF coil of an MRI system and a drive circuit that includes opto-isolator circuitry configured to control the switching circuitry. Some embodiments provide an MRI system that includes an RF coil configured to, when operated, transmit and / or receive RF signals to and / or from a field of view of the MRI system, switching circuitry coupled to the RF coil, and a drive circuit that includes opto-isolator circuitry configured to control the switching circuitry.

Systems and methods for determining oxygen consumption using magnetic resonance imaging (MRI) are provided. In some implementations, a method includes steps for applying a pulse sequence using an MRI system to a region of interest (ROI) in a subject, and acquiring magnetic resonance (MR) signal data from the ROI using the MRI system. The method also includes steps for reconstructing the MR signal data using a reconstruction algorithm to derive at least one motion-controlled, blood oxygenation-weighted image, and at least one blood-flow image; and analyzing the at least one motion-resolved, blood oxygenation-weighted image to determine oxygen consumption in the ROI.

A system for RF based frequency encoding utilizing a Bloch-Siegert shift, includes a controller, an RF encoding system, and an injection transformer simultaneous transmit and receive filter. The controller generates RF excitation pulses, RF based frequency encoding pulses, and a cancellation signal. The RF encoding system includes one or more RF coils configured to transmit the RF excitation pulses and RF based frequency encoding pulses, and to receive an MR signal from the subject where the MR signal includes a leakage signal induced by the RF based frequency encoding pulses. The injection transformer simultaneous transmit and receive filter is in signal communication with the controller and the RF encoding system. The injection transformer simultaneous transmit receive filter is configured to receive the cancellation signal, the MR signal including the leakage signal, and to cancel the leakage signal from the received MR signal to generate a filtered MR signal.

A quantitative, ultrashort time to echo, contrast-enhanced magnetic resonance imaging technique is provided. The technique can be used to accurately measure contrast agent concentration in the blood, to provide clear, high-definition angiograms, and to measure absolute quantities of cerebral blood volume on a voxel-by-voxel basis.

A magnetic resonance imaging method and system are provided. The method includes obtaining first image data using a first scan sequence, filtering the first image data to generate second image data, and estimating a radio-frequency field map based on the first and second image data. Scanned image data is then acquired using a second scan sequence and corrected using the estimated radio-frequency field map to obtain the corrected image data.

The present invention relates to computer-implemented methods and systems for characterising the microstructural composition of a blood vessel and the pathological features therein, utilising magnetic resonance quantitative susceptibility mapping and machine learning or Al models. Methods and systems providing explainable quantitative rupture risk assessment of plaques and aneurysm in target blood vessels, particularly carotid arteries, are disclosed. An advantage of the invention is to provide explainable plaque and aneurysm rupture, risk scores based on a single measurement sequence, resulting in a cost, time, and resource efficient risk assessment.

Systems and methods are provided for determine the fat composition in an organ of interest using a non-invasive health measurement system. The non-invasive health measurement system may include an open magnet NMR apparatus. The NMR apparatus may measure NMR signals in a sensitive volume of a patient. The sensitive volume may coincide with an organ of interest, such as a liver. Systems and methods disclosed herein may provide for separation of the water contribution and the fat contribution to the measured NMR signal. Diffusion based separation, T2 based separation, and T1 based separation may each serve as different methods for separating the water and fat contributions to the signal. Separating the water and fat contributions to the single may allow for computation of a proton density fat fraction which may reflect the fat composition of the organ of interest.