289 results about "Magnet resonance imaging" patented technology

The invention relates to an infantile autism classification method based on a double-branch functional topological graph neural network. The infantile autism classification method can realize the classification of the infantile autism by using functional magnetic resonance imaging data. According to the provided autism classification network, long-distance connection and short-distance connection are divided based on the shortest path between brain intervals, then an exponential decay mask is introduced through a functional topological graph Transform branch to adjust attention weight and accurately extract long-distance dependency features, a graph isomorphic network in the other branch is subjected to multiple neighborhood aggregation operations, short-distance dependency features are captured, and the short-distance dependency features are extracted. According to the method, multi-scale dependence of the brain network is extracted in parallel through a double-branch structure, information redundancy is reduced by means of a topology perception attention mechanism, and the adaptive ability of the model to the heterogeneous brain network is improved by using the adaptive fusion module, so that multi-scale dependence of the heterogeneous brain network is balanced in a self-adaptive manner. The classification accuracy is remarkably superior to that of an existing mainstream method, objective and efficient technical support is provided for autism diagnosis, and high interpretability is achieved.

The invention belongs to the technical field of biological medicine and electronic information technology, and discloses an atherosclerosis model based on nano-molecule magnetic resonance imaging and a machine learning algorithm, a nano-targeting probe and application of the atherosclerosis model based on the nano-molecule magnetic resonance imaging and the machine learning algorithm. A high-resolution MRI image capable of specifically displaying foam macrophage distribution in the plaque is obtained; then, image omics features are extracted from the images, a machine learning model which is constructed based on the features and verified by pathological labels is adopted for analysis, and finally an objective and quantitative plaque vulnerability score is output. According to the model disclosed by the invention, an objective and quantitative risk score can be output by fusing nano-targeted molecular imaging and machine learning, and accurate and reliable quantification of plaque vulnerability is realized. According to the invention, through systematic integration of targeted molecular imaging and machine learning, significant technical progress is brought.

The purpose of the present invention is to provide a magnetic resonance imaging apparatus and a method for controlling a refrigerator. The magnetic resonance imaging apparatus increases the operating rate of an MRI apparatus by prolonging the replacement life of the refrigerator and reducing the replacement frequency of the refrigerator. And executing a cold head life prolonging mode. In the cold head life extension mode, regardless of the temperature of the superconducting coil, the displacer of the refrigerator is moved at a constant frequency lower than a predetermined upper limit frequency, and the drive frequency of the compressor drive unit adjusted by the compressor inverter is controlled in accordance with the temperature of the superconducting coil.

The invention discloses an autism detection method based on multi-mode collaborative embedding, and belongs to the technical field of medical image analysis and artificial intelligence. The method comprises the following steps: firstly, obtaining resting state functional magnetic resonance imaging data and non-imaging data of a subject; a Markov transition field is utilized to encode the time sequence into an image so as to retain dynamic features, and feature extraction is carried out through an efficient multi-scale attention module; then realizing effective fusion and semantic alignment of multi-modal information by adopting a three-level fusion architecture and a joint loss function; and then adaptively constructing a graph structure based on the fusion features, dynamically learning a node relationship by using a graph attention network, and completing a classification decision. According to the method, the defects of a traditional method in the aspects of dynamic feature modeling, multi-modal fusion and heterogeneous graph structure processing are effectively overcome, the autism detection accuracy and robustness are remarkably improved, and a reliable tool is provided for clinical intelligent diagnosis.

The invention provides a scalp-to-brain magnetic resonance imaging generative model training method, a scalp-to-brain magnetic resonance imaging generative model generating method and scalp-to-brain magnetic resonance imaging generative model generating equipment, and relates to the technical field of image processing. The network comprises an encoder, a generator, a feature discriminator and an image discriminator, the encoder and / or the generator is integrated with a neural network model based on a frequency domain attention mechanism, and the encoder and the generator jointly form a target generation model after being trained; and the model parameters are jointly optimized by using a composite loss function comprising a frequency domain loss item. According to the method, the problems that an existing brain image generation technology neglects scalp structure information and is difficult to model global dependence and high-frequency details can be solved, brain magnetic resonance imaging data can be highly generated from scalp magnetic resonance imaging data, the structural integrity and topological fidelity of the generated data can be improved, and the application reliability of auxiliary diagnosis can be improved.

The invention discloses a calculation method for integrating task induction and intrinsic spontaneous brain function activity. The calculation method comprises the following steps: calculating a brain activation mode when an individual executes a corresponding cognitive task based on task state functional magnetic resonance imaging data and a general linear model; identifying individual large-scale nerve avalanche with spatial continuity based on resting state functional magnetic resonance imaging data; the method comprises the following steps: performing principal component analysis on resting state functional magnetic resonance data of an individual to construct a low-dimensional state space; a task-induced brain activation mode and intrinsic spontaneous nerve avalanche are projected to an individual low-dimensional state space; calculating the Euclidean distance between the task-induced brain activity and the intrinsic spontaneous nerve avalanche in the low-dimensional state space; and detecting the prediction effect of the geometric distance on the performance of the tested task through the regression model. The method is verified on a real data set, and experimental results show that the method not only can integrate two basic brain function activities, but also can significantly predict individual cognitive performance differences.

The magnetic resonance imaging (MRI) device comprises a magnet unit, a patient table, and a patient position detection device. The magnet unit surrounds a patient acquisition area defined by an inner wall of the magnet unit and includes a whole-body coil. The patient table is movable within the patient acquisition area. The patient position detection device comprises a sensor unit, a determination unit, and a verification unit. The sensor unit is designed to determine the patient's position on the patient table. The determination unit is designed to determine the distance between the patient and the inner wall based on this position information. The verification unit is designed to check the patient's positioning against a distance limit based on this distance.

The invention provides a self-adaptive tuning matching and control system of a magnetic resonance radio frequency transmitting coil, and belongs to the technical field of magnetic resonance imaging. The system is composed of a radio frequency transmitting coil, a tuning matching circuit of the radio frequency transmitting coil, an automatic adjusting device, a scattering parameter measuring device, an upper computer interaction module, a PC and a computer processing program. During working, the system only needs to pre-store a group of optimal tuning and matching scattering parameters, after different parts of different human bodies enter the center of the body coil, tuning and matching circuits can be continuously adjusted, changes of the scattering parameters in the adjusting process are collected in real time, and the rotating direction of a tuning strip matching motor can be automatically judged; and the accurate tuning frequency and the optimal matching state are quickly obtained, so that the optimal transmitting efficiency is achieved.

Systems and methods for training a machine-learning model to generate denoised and dealiased image data are provided. The present disclosure provides techniques for training a machine-learning (ML) model to generate denoised and dealiased imaging data. A method includes (1) training a first ML model using a first training dataset comprising first image data to obtain a second ML model; and (2) training (a) the second ML model or (b) a third ML model using a second training dataset to obtain a fourth ML model. The second training dataset includes (i) the first image data and (ii) training image data obtained by applying at least one of the second ML model or the third ML model to second image data. The denoising and dealiasing ML model may be either the fourth ML model or derived from the fourth ML model.

This invention discloses a large-aperture interventional magnetic resonance imaging (MRI) system, belonging to the field of imaging system technology. It includes a self-test module, an operation module, an imaging module, a guidance module, an early warning module, and an evaluation module. Before operation, the self-test module acquires multiple parameters of the MRI system, establishes operating coefficients using formulas, and determines whether the MRI system can support surgery based on the comparison between the operating coefficients and a first threshold. The operating coefficients are then sent to the early warning module. This invention's pre-use self-test effectively ensures the stability of the system during operation. Furthermore, during surgery, it acquires the operating coefficients of the MRI system in real time and determines whether an early warning signal needs to be issued based on the comparison between the operating coefficients and a second threshold. When an early warning signal is issued, timely management is implemented, effectively reducing surgical risks.

A parallel scalable architecture and highly integrated Simulcast X-nuclei MRI system includes a multi-nuclear scanning and reconstruction computer and a multi-nuclear scanning control unit. The multi-nuclear scanning control unit includes a multi-nuclear timing sequence control engine, a multi-nuclear radio frequency (RF) signal transmission unit, a multi-nuclear RF signal acquisition unit, a gradient signal generation unit, and a multi-nuclear coil tuning control unit. The multi-nuclear timing sequence control engine is separately connected to the multi-nuclear RF signal transmission unit, the multi-nuclear RF signal acquisition unit, the gradient signal generation unit and the multi-nuclear coil tuning control unit. The parallel scalable architecture and highly integrated Simulcast X-nuclei MRI system is designed to support synchronous or time-sharing excitation and acquisition of signals of a plurality of types of nuclides, including but not limited to hydrogen, fluorine, phosphorus, sodium, and other nuclides.

The utility model discloses a fan assembly, patient ventilation system and magnetic resonance imaging system for patient ventilation system in magnetic resonance imaging system, wherein, fan assembly includes: fan group, it includes at least two axial flow fan, at least two axial flow fan is fixed with the way of realizing air port series pressurization, magnetic shielding casing, it covers the periphery of fan group, air inlet connector, it is arranged on the air inlet side of magnetic shielding casing near fan group for with the air inlet pipeline connection of patient ventilation system, and air outlet connector, it is arranged on the air outlet side of magnetic shielding casing near fan group for with the patient ventilation pipeline connection of patient ventilation system. The technical scheme in the utility model embodiment can solve the patient ventilation problem of MRI system.

The present application relates to the technical field of nanoprobes, and particularly relates to a near-infrared fluorescence / magnetic resonance dual-mode probe and a preparation method and application thereof. The present application adopts a Brij98 amphiphilic molecule to wrap an IR824Et-PhDTA-Gd near-infrared fluorescence / magnetic resonance dual-response molecule to prepare the probe, so that the probe has an absorption wavelength of 650-850 nm, generates a fluorescence signal under excitation of 785 nm laser, and the generated fluorescence wavelength can reach 1000 nm, which is in a near-infrared region (780-1700 nm); the probe has good positive magnetic resonance response characteristics, and a longitudinal relaxation rate (r1) of the probe is 28 mM ‑1 s ‑1 , which is 7 times of that of a clinically used Magnevist; the probe can be applied in the fields of fluorescence and / or magnetic resonance imaging, and has a wide application prospect. The preparation method of the near-infrared fluorescence / magnetic resonance dual-mode probe is simple in operation and low in cost.

The present disclosure describes systems and methods of magnetic resonance imaging (MRI) that provide B1 field mapping and B1 field spoiling without a plurality of B0 gradient fields. An off-resonant pulse may be applied, or delivered, to the object of interest following an excitation pulse to induce a phase shift, which may be measured to determine the B1 field map. Also, a spoiling off-resonant RF pulse may be applied, or delivered, to the object of interest to remove unwanted signal coherence pathways in the region of the object.

The present disclosure provides a system for localizing the position of an endovascular probe and collecting high-resolution images of the anatomy surrounding the probe. In particular, a switchable endovascular imaging antenna / probe and related devices are disclosed, which are conveniently switchable between a configuration that allows the localization with high precision of the distal tip of an endovascular probe, and another configuration that allows imaging in the locality of the probe tip. Embodiments are also disclosed capable of delivering ablation therapy.

The utility model relates to a magnetic resonance up-down opening and closing coil and a magnetic resonance imaging device, and the magnetic resonance up-down opening and closing coil comprises an upper coil, two locking assemblies, a lower coil, an elastic assembly corresponding to the locking assemblies, an operation unit, and a traction part corresponding to the locking assemblies. The two locking assemblies are arranged on the two sides of the upper coil in the radial direction respectively, and each locking assembly is provided with a locking position and an unlocking position; the two sides of the lower coil in the radial direction are each provided with a matching structure used for being matched with the locking assembly in a locking mode. The elastic assemblies are arranged on the upper coil, the locking assemblies are connected to the upper coil through the corresponding elastic assemblies, and the elastic assemblies are used for driving the corresponding locking assemblies to be located at the locking positions; the operation unit is arranged on the upper coil, one end of each traction piece is connected with the operation unit, and the other end of each traction piece is connected with the corresponding locking assembly; the operation unit operably drives the traction pieces to move.

A power supply assembly of a gradient coil are provided. The power supply assembly of the gradient coil may include a first insulation device, wherein the first insulation device is located within a scanning channel of a main magnet and connected to one end of the gradient coil, the first insulation device may be arranged with a first conductive unit, the conductive unit may be a rigid conductor, a first end of the first conductive unit may be electrically connected with the gradient coil of a magnetic resonance imaging system, and a second end of the first conductive unit may be electrically connected with a cable of the magnetic resonance imaging system.

A radiotherapy device (100, 320) and a magnetic resonance guided radiotherapy system (300, 400, 500, 600, 700). The radiotherapy device (100, 320) can include an electron gun (110) and a curved beam current deflection unit (120, 409, 509, 609, 709). The beam current deflection unit (120, 409, 509, 609, 709) is configured to accelerate an electron beam output by the electron gun (110) over a range of magnetic field strengths (B0). The magnetic resonance guided radiotherapy system (300, 400, 500, 600, 700) can include the radiotherapy device (100, 320) and a magnetic resonance imaging device (310).

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).

The application relates to a radio frequency coil design method for transmit array spatial encoding imaging, and belongs to the technical field of magnetic resonance imaging. In view of the problems of low single-dimension coding efficiency, strong coupling interference between coils and nonlinear phase gradient of a traditional TRASE technology, axial and radial coding coils are designed based on a target field method and a magnetic dipole method, two-dimensional radio frequency phase coding is realized through reverse current solenoid decoupling combination, and excitation and signal receiving are realized in combination with a saddle coil. Through optimization of the coil structure and decoupling design, the technical scheme achieves multi-dimensional efficient coding, high-precision phase gradient, strong anti-interference and system light weight, and is suitable for the portability and dynamic monitoring scene of low-field magnetic resonance.

The application provides a portable magnetic resonance imaging-based brain disease remote diagnosis system, and belongs to the cross field of medical imaging and remote medical treatment.The system comprises a portable magnetic resonance imaging device, a remote data transmission and cooperation network and a remote diagnosis and AI auxiliary workstation; wherein the portable magnetic resonance imaging device is arranged in a primary medical institution, is used for performing standardized scanning on a patient's brain disease under a low-field magnetic field, and acquires brain image data of the patient; the remote data transmission and cooperation network is used for connecting the device end and the diagnosis end, and is used for transmitting the brain image data to the remote diagnosis and AI auxiliary workstation; and the remote diagnosis and AI auxiliary workstation is used for performing brain disease analysis based on the brain image data and generating a structured report, and the report is returned to the primary medical institution.The application combines remote medical treatment and on-site magnetic resonance scanning, optimizes medical resources, and improves diagnosis effect.

A transmit / receive switch for magnetic resonance imaging (MRI) of a 1H atomic nucleus at 3T (tesla) and 7T magnetic field strengths includes a first and second dielectric substrate and a first and a second microstripline hybrid coupler formed on the first and second dielectric substrates respectively. A first port and a second port are connected to a first junction and a second junction respectively of the first microstripline hybrid coupler, a third port and a fourth port are connected to a third junction and a fourth junction of the second microstripline hybrid coupler respectively. Each port is connected by a matching network embodied by a microstripline wire to a pair of parallel resonant circuits. The transmit / receive switch is configured to operate at a fundamental frequency of about 127.8 MHz at 3T and at a third harmonic frequency of about 298 MHz at 7T.

A method for manufacturing an over-molded resonator for a radio frequency receive coil assembly (180) of a magnetic resonance imaging system (100), the method comprising providing a pair of wires (250), where each wire (250) of the pair of wires (250) has a set desired length. The method also includes holding the pair of wires (250) in a fixed spatial arrangement relative to each other. The method further includes overmolding a dielectric material (256) over the pair of wires (250) to form an overmolded wire assembly (248). The method even further includes coupling the pair of wires (250) to an electronic unit (185).

The invention relates to a magnetic resonance imaging device comprising a magnetic enclosure (1) having a tubular enclosure body (2) comprising a main part (2A) interposed between two end parts (2B, 2C), a first series of permanent magnet support plates (20) forming the main part (2A) of the enclosure body (2), a second series of permanent magnet support plates (21) forming at least one of the two end parts (2B, 2C), means for assembling the support plates (20, 21) of the first and second series to one another, the assembly means comprising a first arrangement of one or more rails comprising at least one alignment rail (3) having a main rail segment provided with notches for retaining the support plates (20) of the first series and at least one end rail segment, adjacent to the main rail segment (30), comprising a flat surface (33) on which the support plates (21) of the second series are fixed.

The embodiment of the application discloses a kind of Alzheimer's disease classification and key brain area determination method based on random attention and counterfactual contrast learning, it is related to medical image analysis technical field;Alzheimer's disease classification and key brain area are determined by the functional magnetic resonance imaging data of subject;The accuracy, overall performance and stability of the graph convolution network model are significantly better than the existing GNN baseline model in the AD vs.NC task of ADNI real data set;The output key brain area node is highly consistent with clinical medicine priori;Specific brain area and functional connection leading to abnormal classification can be intuitively presented;It conforms to the real pathological mechanism, and whether the verification model in the same framework is really highly dependent on the selected key brain area structure, so that the explanation result can be accepted by clinician in the medical scene with extremely high safety requirement.

The invention relates to a magnetic resonance imaging device (1) comprising a magnetic assembly (MagAss) that generates a permanent magnetic field (B0) along a magnetization axis, the magnetic assembly (MagAss) comprising: support plates (SupPl) supporting permanent magnets (Mag) forming at least one Halbach ring (HlbRng), the Halbach rings being coaxial and configured so that each one generates a magnetic field (BRng) parallel to the magnetization axis, the support plates comprising at least one first end support plate (SupPl1), at least one second end support plate (SupPl2), and a plurality of central support plates (SupPl0) interposed between the end support plates, and the permanent magnets (Mag1, Mag2) supported by the end support plates each having a first volume, the permanent magnets (Mag0) supported by the plurality of central support plates each having a second volume, the first volume being larger than the second volume.

By extending the lifespan of the refrigeration unit and reducing the frequency of replacement, the operating rate of the MRI system will be improved. [Solution] The cold head life extension mode is implemented. In the cold head life extension mode, the refrigerator's displayer is operated at a constant frequency lower than a predetermined upper frequency, regardless of the temperature of the superconducting coil, and the compressor inverter controls the drive frequency of the compressor drive unit according to the temperature of the superconducting coil.

The invention relates to the technical field of uterus image segmentation, in particular to a woman uterus disease auxiliary diagnosis and evaluation system based on magnetic resonance imaging. After a uterus image of a patient is obtained and a uterine cavity area is positioned, clustering clusters are divided according to pixel gray values by using a clustering algorithm to correspond to different uterus areas. And generating an endometrial region descriptor and screening out an endometrial region by combining the pixel number distribution of each region, the gray features and the shape difference between the endometrial region descriptor and the uterine cavity. Performing gray scale segmentation on the region to extract a high-signal region, and calculating an internal descriptor according to internal edge distribution and morphological characteristics of the high-signal region; meanwhile, an external descriptor is generated based on edge pixel neighborhood gray scale difference. And finally fusing internal and external descriptors to realize auxiliary diagnosis of uterine diseases. According to the method, the uterus image with obvious uterine cancer staging development tendency can be screened out, and a more accurate diagnosis effect is provided for related personnel.