44 results about "K-space" patented technology

The invention discloses a multi-contrast magnetic resonance image reconstruction method and device based on detail contour feature perception. The method comprises the following steps: acquiring a target modal initial image and an auxiliary modal initial image; constructing an iterative network formed by alternately cascading image domain reconstruction units and data consistency layers, wherein each image domain reconstruction unit comprises an encoder and a decoder; in the first iteration, target modal initial images and auxiliary modal initial images are spliced and then input, an encoder extracts shared features firstly, then global contour features and high-frequency detail features are separated in parallel, and potential features are obtained through collaborative fusion; the decoder takes the potential features as input and outputs an image domain preliminary reconstruction result; the data consistency layer transforms the preliminary result into a k space, performs consistency correction on the preliminary result and a target modal sampling point, and then inversely transforms the preliminary result back to an image domain to complete one iteration; and splicing the current output and the auxiliary modal initial image again, inputting the spliced image into a next round of iteration, and repeating the process until a preset number of times to obtain a final target modal magnetic resonance image.

The invention provides a medical magnetic resonance image reconstruction method and system, and belongs to the technical field of image reconstruction, and the method comprises the steps: obtaining sampling coding and under-sampling k space data; processing the under-sampled k space data through inverse Fourier transform, and converting the k space data into an image domain to obtain under-sampled image data with blurring or artifacts; carrying out preliminary restoration on the undersampled image data based on sampling coding, further applying data consistency operation on the image to obtain a rough image, and taking the rough image as an image condition vector after underspace coding; acquiring a text serving as a cue word, inputting the text into a text encoder, and encoding the text into a high-dimensional semantic embedding vector by the text encoder; and inputting the high-dimensional semantic embedding vector and the image condition vector into a reconstruction model based on the correction flow to predict a full-sampling MRI image, and generating a final reconstructed MRI image.

The invention provides a magnetic resonance free respiration data extraction method based on a respiratory wave extraction algorithm, and relates to the technical field of respiration acquisition, and the method comprises the following steps: obtaining a rapid imaging sequence, and extracting a complex number sampling value of a center k space line of the rapid imaging sequence in a z direction as an initial input signal; performing z-direction IFFT interpolation processing on the initial input signal to output a high-resolution z-t signal matrix; performing time dimension signal smoothing processing on the high-resolution z-t signal matrix; performing normalization processing on the z-axis signal at each time point based on a smoothing processing result; the z-axis signals of all the channels are spliced along the longitudinal axis according to the normalization processing result to form a unified matrix; the unified matrix is subjected to standard PCA decomposition, and principal components of the unified matrix are extracted to obtain respiratory wave data; according to the method, the breathing signal waveform can be stably extracted from the MRI original k space in the free breathing state without depending on the breath holding condition, and the structure consistency and time synchronism of breathing waves are improved.

The invention discloses a parallel MRI (Magnetic Resonance Imaging) reconstruction method based on a scanning specific triple attention improved residual network, and belongs to the field of MRI imaging. And acquiring full-sampling multi-coil k-space data, and performing multiple operations on the full-sampling multi-coil k-space data to obtain under-sampling multi-coil k-space data. Designing a specific triple attention improved residual parallel MRI reconstruction network (SS-TARNet) based on scanning, wherein the SS-TARNet is a reconstruction network model with adaptive and multi-scale feature extraction; constructing a mixed loss function of the reconstructed network model; solving the optimal parameters of the reconstructed network model by using the training set, the verification set and the mixed loss function; and for the test set, performing MRI image reconstruction by using the optimal parameters of the reconstruction network model to obtain a reconstructed image. The final reconstruction result is amplitude fusion of the sum. According to the method, the reconstruction results obtained by the two different networks are uniquely utilized to perform amplitude fusion output, and a better reconstruction effect is obtained, so that the reconstruction performance in the under-sampling MRI scene is greatly improved.

The invention discloses a full-space switchable nanoimprint and holographic display method based on a metasurface, and belongs to the field of micro-nano optics and holographic display. According to the metasurface-based full-space switchable nanoimprint and holographic display method, the metasurface used for achieving full-space switchable nanoimprint and holographic display is composed of nano antennas of different geometric dimensions, and the geometric dimensions and the arrangement mode of the metasurface are determined through an amplitude constrained phase holographic optimization algorithm; the amplitude distribution of the light field passing through the metasurface is restrained into binary image distribution in a real space, and holographic reconstruction is carried out in a wave vector k space. According to the sensitivity of the metasurface to the wavelength of incident light, three different optical modulation modes are realized under three wavelengths; the wavelength sensitivity of the metasurface is utilized to modulate a reflected light beam and a transmitted light beam under different incident light wavelengths, so that full-space switchable nanoimprint and holographic display are realized, and the metasurface can be applied to the fields of optical nanoimprint, counterfeiting prevention, optical switches, optical communication, display and the like.

The application discloses a kind of low field intensity magnetic susceptibility weighted imaging optimization method and system, it is related to magnetic susceptibility weighted imaging field, comprising: obtaining the K space original data obtained by scanning target object;According to K space original data reconstruction image field data, extract the amplitude data and phase data of image field data;Phase data is preliminary unwrapping processing, and unwrapping phase data is obtained;Unwrapping phase data is separated from background field, and local phase diagram is obtained;Local phase diagram and amplitude data are operated based on complex domain phase separation high-pass filter, and high-frequency phase data is obtained;According to high-frequency phase data and amplitude data, the reconstruction of magnetic susceptibility weighted image is carried out, and the magnetic susceptibility weighted image of target object is obtained.The application can significantly reduce the phase artifact of SWI image, and improve the definition of image detail.

The invention provides a respiratory-gating-free free-breathing liver glycogen quantitative magnetic resonance imaging method and system, and the method comprises the steps: applying a chemical exchange saturation transfer imaging sequence to a liver region of a subject, and the imaging sequence comprises saturation pulses of a plurality of saturation frequency deviation points; a radial blade type k-space acquisition strategy is adopted to acquire magnetic resonance signal data, the radial blade type k-space acquisition strategy comprises a plurality of blades, each blade is composed of a group of parallel k-space lines, and different blades are rotationally distributed by taking the k-space center as a rotating shaft; performing image reconstruction on the acquired k space data to obtain magnetic resonance images under different saturation frequency deviations; and performing fitting analysis on the magnetic resonance image by adopting a multi-pool Lorentz model to obtain quantitative information of the liver glycogen. According to the method, the interference of respiratory movement on the CESTMRI data acquisition process can be eliminated, so that the accurate quantification of the liver glycogen in the free respiration state is realized.

The invention relates to a magnetic resonance image processing method and device, and an EPI-based image processing method. The method comprises the steps of obtaining a first sampling image of a target object according to sensitivity information of a receiving coil corresponding to the target object and K space data; correcting artifacts in the first sampling image to obtain a second sampling image of the target object; and iterating data of a preset first magnetic resonance image by taking the second sampling image as a constraint condition and taking the K space data as a fidelity term in an iterative reconstruction process to obtain a magnetic resonance image of the target object. By adopting the method, the problem of aliasing artifacts existing in magnetic resonance imaging images can be solved.

The invention discloses a method, a device, equipment and a product for reconstructing a spatially selective core measurement image, which comprises the following steps of: acquiring k-space data of a core to be measured by using a k-space radial sampling mode, and then, acquiring the k-space data of the core to be measured by using the k-space data; constructing an image model based on the image of the rock core to be measured, the k-space data and the contour data of each spoke in the k-space data; then, image reconstruction can be carried out based on the image model, so that in the image reconstruction process, the adverse effect of the contour data of each spoke in the k space data on rock core imaging is eliminated, and the optimal image of the rock core to be measured is obtained; and finally, based on this, obtaining a corresponding spatial selective core measurement image. Therefore, the image reconstruction is realized by utilizing an algorithm, and compared with the traditional technology, the method does not need to change hardware, is high in feasibility, and can greatly reduce the influence of profi on the image quality, so that the image reconstruction quality can be remarkably improved.

The invention is suitable for the technical field of magnetic resonance chemical exchange saturation transfer imaging, and provides a magnetic resonance chemical exchange saturation transfer imaging method, device, equipment, product and storage medium. A gradient echo sequence is adopted to collect saturated water molecule signals, and the collected water molecule signals are stored in a K space; and wave control coding is introduced in the acquisition process, and a CEST image is reconstructed based on a water molecule signal of a K space. The introduction of wave control coding can reduce the scanning time. Due to the fact that the wave control coding sampling efficiency is high, a larger matrix size can be supported within the same time, high-resolution imaging is achieved, the partial volume effect can be relieved, and CEST quantitative accuracy is improved.

The present disclosure provides a system and method for magnetic resonance imaging. The method may include obtaining a first set of imaging data, the first set of imaging data being sampled in multiple shots, each shot of the multiple shots corresponding to a plurality of echo times, the first set of imaging data including partially sampled data in a first k space; obtaining a second set of imaging data, the second set of imaging data including fully sampled data in a central region of a second k space; determining fitting data in the first k space based on the first set of imaging data and the second set of imaging data; and / or generating a target image based on the fitting data in the first k space and the first set of imaging data in the first k space.

The invention relates to a system and a method for K-space neutron space parallel imaging. A computer-implemented method includes obtaining, via a processing system including one or more processors, multichannel k-space data of a subject acquired with a magnetic resonance imaging scanner. The computer-implemented method further includes combining, via the processing system, information from locally adjacent k-space locations and across a plurality of channels using a subspace convolution kernel on the multi-channel k-space data to generate subspace compressed k-space data, the subspace compressed k-space data has fewer channels than the number of channels used to collect the multi-channel k-space data.

The application provides a small animal sciatic nerve magnetic resonance coil and an imaging method, and the method comprises the following steps: filling a high-concentration sugar syrup solution at the bottom of the magnetic resonance coil and performing constant temperature control; placing a small animal in a prone position in the high-concentration sugar syrup solution and discharging air in the gap between the lower limbs and below the abdomen of the small animal; after performing magnetic resonance positioning scanning to determine the main sequence scanning range, starting the main sequence scanning, suppressing the flow tissue signal through a pre-pulse combination, exciting the tissue by using a radio frequency pulse with preset parameters, acquiring echo signals by combining a fast spin echo technology and filling K space, and obtaining scanning original data; performing preprocessing on the scanning original data and accurate segmentation of the sciatic nerve and spinal nerve to obtain a segmentation result; and completing three-dimensional model reconstruction, optimization and multi-modal fusion visualization based on the segmentation result to obtain an image scanning result. The application is suitable for small animals, is accurate in imaging, can effectively suppress various kinds of artifacts, and can be widely applied to sciatic nerve imaging scenarios of small animals.

The embodiment of the invention discloses an under-sampling point recovery method and device in magnetic resonance imaging and a magnetic resonance imaging system. The method comprises the following steps: in the process of performing magnetic resonance scanning on an imaging target by adopting a multi-echo data imaging merging sequence, acquiring magnetic resonance signals of echoes of channels in an undersampling mode, and putting the acquired magnetic resonance signals of the echoes of the channels into K spaces of the echoes of the channels respectively, each channel has a plurality of echoes, and each echo of each channel corresponds to a K space; and for an under-sampling point in the K space of a specified echo of a specified channel of the imaging target, recovering the under-sampling point by adopting the magnetic resonance signals in the K spaces of the echoes of all channels and the magnetic resonance signals in the K spaces of other echoes of the specified channel. According to the embodiment of the invention, the under-sampling point recovery accuracy during MR imaging by adopting the MEDIC sequence is improved.

Embodiments of the present application disclose a multi-echo data magnetic resonance imaging scanning method, device and magnetic resonance imaging system. The method comprises: in the process of multi-echo data magnetic resonance imaging scanning on an imaging target, if automatic calibration data needs to be collected in the current repetition time, and the position of the automatic calibration data in K space is inconsistent with the position of any imaging data in K space which needs to be collected in the current repetition time, then: when the plateau signal of the first readout gradient in the readout direction is applied, start to apply an offset gradient in the phase encoding direction, wherein the first readout gradient is any readout gradient in the readout direction except the last readout gradient; and during the application of the plateau signal of the dephasing gradient of the first readout gradient in the readout direction, the automatic calibration data is collected. Embodiments of the present application avoid TR oscillation in multi-echo data MR imaging scanning, and realize the continuity of the collected automatic calibration data and imaging data.

The invention discloses a self-supervised parallel MRI (Magnetic Resonance Imaging) reconstruction method based on a deep double-domain fusion network. The method comprises the following steps: constructing an up-down parallel comparison network based on the deep double-domain fusion network; in the training stage, simulation enhancement and re-undersampling are carried out based on an original sampling mask, a re-undersampling mask pair is generated, and comparison and re-undersampling k space data are obtained; respectively inputting the two paths of data into a parallel comparison network for comparison self-supervision training; a mixed loss function of the network comprises image domain calibration loss, symmetry constraint loss and projection prediction comparison loss, and network parameters are optimized under the condition of no full sampling reference image to obtain a trained model. According to the method, the reconstruction quality can be improved and the artifact noise can be suppressed without full sampling labeling, the generalization of cross-mask and cross-acceleration factors is enhanced, and the data acquisition, training and deployment maintenance cost is reduced.

The invention discloses a reconfigurable magnetic resonance image reconstruction system and a dynamic control method thereof. The system comprises an input adapter, a module manager, a pipeline manager, an execution engine, a plurality of processing modules and an output adapter. According to the system, registration and instantiation of the processing modules are achieved through the module manager, declarative configuration files are analyzed through the assembly line manager to construct an execution topology, a unified data container is dynamically scheduled through an execution engine according to the topology to flow through all the processing modules, and the reconstruction process from k space data to diagnostic images is completed. According to the system and the dynamic control method thereof, flexible recombination of the reconstruction process and dynamic control during operation are achieved, the problems that in the prior art, the process is rigid, expansion is difficult, and cross-language compatibility is insufficient are solved, and adaptability, expandability and reconstruction efficiency of the system are remarkably improved.

The application discloses a kind of quantitative magnetic susceptibility imaging method and device based on radial sampling, comprising: by magnetic resonance scanner executes three-dimensional gradient echo multi-echo sequence, and the three-dimensional k space multi-echo data of tissue is collected in radial sampling mode;The three-dimensional k space multi-echo data collected is corrected and density is compensated to obtain the three-dimensional k space multi-echo data and corrected track RT after track correction and density compensation;The three-dimensional k space multi-echo data and corrected track RT after track correction and density compensation are input into non-uniform fast Fourier transform reconstruction complex image, to obtain corresponding amplitude diagram and phase diagram;Phase diagram is unwound and background field is removed, to obtain corresponding local field;By improved sparse linear equation and least square method ILSQR algorithm inversion local field, corresponding magnetic susceptibility distribution diagram is generated.The method and device of the application reduce the influence of motion artifact, improve imaging quality and diagnostic accuracy.

The present application relates to a kind of wideband omni-directional completely transparent system and its application of torsion structure implementation, the system includes several first structure and second structure connected alternately, the first structure rotates set angle in Z axis direction towards clockwise direction, the second structure rotates set angle in Z axis direction towards counterclockwise direction;The first structure and the second structure all include several first structure layer and second structure layer, which are arranged in up-down overlap along X axis direction;The omni-directional completely transparent system meets the following zero shift condition.The system of the present application realizes the rotation of IFCs (Iso-frequency curves, equal frequency curve) in k space by twisting by multiple layers of alternatingly arranged dielectric materials, and realizes wideband OPT under zero reflection condition.

The invention discloses a method and a device for identifying and eliminating low-frequency strong interference noise of a magnetic resonance system, which are characterized in that after being processed by a conventional self-adaptive noise reduction method, signals in a k space which is not influenced by low-frequency strong EMI (Electro-Magnetic Interference) along frequency and phase encoding directions are smooth, and the low-frequency strong EMI is discontinuous in the phase encoding direction, so that the low-frequency strong interference noise can be identified and eliminated. According to the characteristic that the signal is in a peak shape in time sequence, low-frequency strong EMI post-processing identification and elimination are carried out on the signal after self-adaptive noise reduction; therefore, the low-frequency strong interference noise in the nuclear magnetic resonance signal can be removed, so that the quality of nuclear magnetic resonance imaging is improved; therefore, the method is very suitable for large-scale application and popularization in the field of ultra-low field nuclear magnetic resonance.

The application relates to a parallel emission local excitation pulse generation method, device and storage medium, the method comprising: generating a radio frequency pulse according to a three-dimensional mapping of a test object and a three-dimensional excitation K space; calculating excitation uniformity according to the three-dimensional mapping, the three-dimensional excitation K space and the radio frequency pulse; when the excitation uniformity is less than a preset value, updating the three-dimensional mapping and the three-dimensional excitation K space used for generating the radio frequency pulse and for calculating the excitation uniformity; when the excitation uniformity is greater than or equal to the preset value, generating the parallel emission local excitation pulse according to the three-dimensional excitation K space and the radio frequency pulse currently used for calculating the excitation uniformity. Through the application, the problem that the radio frequency pulse duration is long in the prior art is solved, the local excitation position uniformity in the expected magnetic resonance emission field is achieved, and the radio frequency pulse length is shortened.

A magnetic resonance image reconstruction method reconstructs magnetic resonance image data based on under-sampled K space data, and comprises the following steps: an image space regularization step: regularizing first image data generated based on the under-sampled K space data in an image space by using a first neural network to generate second image data; a deviation correction step of correcting the second image data so that the pixel value statistical feature of the second image data approaches the pixel value statistical feature of the first image data to generate third image data; a data consistency processing step: performing data consistency processing on the third image data in a manner that the K space data corresponding to the third image data is close to the undersampled K space data to generate fourth image data; and an output step of outputting image data based on the fourth image data as reconstructed magnetic resonance image data.

The application relates to an image reconstruction method and device, computer equipment and a storage medium. The application comprises the following steps: acquiring ASL control data and ASL mark data of a target region in K space; independently reconstructing the ASL control data of each segment to obtain a first complete image corresponding to the ASL control data of each segment; independently reconstructing the ASL mark data of each segment to obtain a second complete image corresponding to the ASL mark data of each segment; combining the first complete images corresponding to each segment to obtain a control image of the target region after reconstruction; and combining the second complete images corresponding to each segment to obtain a mark image of the target region after reconstruction. The method can reconstruct an image without artifacts, thereby greatly improving the accuracy of the reconstructed image.

The invention discloses a magnetic resonance image uniformity correction method and system based on three-dimensional sensitivity modeling. The method comprises the following steps: acquiring initial three-dimensional sensitivity data acquired by a multi-channel phased array coil and original image data to be corrected; zero filling processing is carried out on the k space representation of the initial three-dimensional sensitivity data, inverse Fourier transform is carried out on the spatial domain sensitivity after zero filling, and a processed three-dimensional sensitivity graph is obtained; according to scanning geometric parameters of the target magnetic resonance image, the processed three-dimensional sensitivity image is resampled to a two-dimensional plane where the target magnetic resonance image is located, and a two-dimensional sensitivity image matched with the space of the target magnetic resonance image is obtained; and carrying out smoothing filtering processing on the two-dimensional sensitivity image to obtain a smoothed two-dimensional sensitivity image. According to the method and the system, the defects of residual correction, multiple artifacts and poor robustness in the prior art are overcome, and stable and high-quality uniformity correction can be provided for different anatomical parts and coil configuration.

The invention discloses a magnetic resonance image reconstruction method based on matrix filling in the technical field of magnetic resonance imaging reconstruction, and aims to solve the problems of data reconstruction difficulty caused by non-Cartesian sparse sampling and serious aliasing artifact interference caused by high-frequency information loss in the prior art. And a technical problem of low efficiency of a traditional non-uniform Fourier transform reconstruction algorithm is solved. The method comprises the following steps: estimating a low-dimensional data subspace based on a small amount of completely sampled K space data by using an improved SVD algorithm, and remarkably reducing reconstruction calculation complexity through subspace projection; performing low-rank sparse decomposition on the under-sampled K space data by applying a Godec algorithm, and extracting key low-rank components for image reconstruction; carrying out iterative reconstruction on the sampling data in the K space by combining low-rank constraint, and synchronously optimizing image space data; and finally, obtaining a high-quality and low-artifact magnetic resonance image through an iterative reconstruction process. According to the method, aliasing artifacts are effectively suppressed, and the speed and efficiency of magnetic resonance image reconstruction under the non-Cartesian sparse sampling condition are remarkably improved.

The present invention discloses a microscopic angular resolution spectroscopy measurement system that realizes variable-angle excitation based on a reflector, which belongs to the field of microscopic angular resolution spectroscopy measurement. The present invention realizes variable-angle excitation of the sample by changing the incident angle of the reflector so that the incident light beam is focused at different positions of the rear focal plane of the objective lens. The light signals of different angles emitted by the sample are transformed from real space to k space through the objective lens and two plano-convex lenses through Fourier transformation. The image of the k space of the rear focal plane of the objective lens is moved to the slit of the spectrometer. The one-time collection of light signals of different angles significantly shortens the spectrum collection time, thereby improving the efficiency of microscopic angular resolution spectroscopy measurement. The present invention realizes regional illumination and positioning of micron-level samples by adding a micro-area imaging module, and realizes light excitation of predetermined positions of micro-area samples while observing the samples in real time through a semi-transparent and semi-reflective mirror, without switching any optical elements in the light path, so as to collect the angular resolution spectrum of the micro-area samples in real time.

The invention discloses a medium and low field intensity magnetic sensitive weighted imaging optimization method and system, and relates to the field of magnetic sensitive weighted imaging, and the method comprises the steps: obtaining K space original data obtained by scanning a target object; reconstructing image domain data according to the K space original data, and extracting amplitude data and phase data of the image domain data; performing preliminary unwrapping processing on the phase data to obtain unwrapped phase data; performing background field separation on the unwrapping phase data to obtain a local phase diagram; performing high-pass filtering operation based on complex field phase separation on the local phase diagram and the amplitude data to obtain high-frequency phase data; and reconstructing a magnetic sensitive weighted image according to the high-frequency phase data and the amplitude data to obtain the magnetic sensitive weighted image of the target object. According to the method, the phase artifacts of the SWI image can be remarkably reduced, and the definition of image details is improved.

The invention discloses an FSE3D-Stack of Stars sequence phase correction method, device and equipment, a medium and a product, and relates to the technical field of magnetic resonance imaging. The method comprises the following steps: acquiring pre-scanning data in a plurality of radial acquisition directions in a pre-scanning stage; determining phase error data of each echo in each radial acquisition direction based on the pre-scanning data of the central position of the echo chain in a certain radial acquisition direction or the pre-scanning data of the echo chain in the Kz center of a k space and the pre-scanning data of each echo in each radial acquisition direction; based on the phase error data of each echo in each radial acquisition direction, correcting the phase of each echo in the scanning data obtained in each radial acquisition direction in the scanning stage to obtain the corrected scanning data in each radial acquisition direction; wherein the pre-scanning data and the scanning data are both FSE3D-Stack of Stars sequence data. The phase error of the FSE3D-Stack of Stars sequence caused by the asymmetry of the gradient axis and the dependency of the adjoint field effect in the radial acquisition direction can be effectively eliminated.

The invention relates to a magnetic resonance heart movie sequence imaging method and system, a terminal and a medium, and relates to the technical field of magnetic resonance imaging, and the method comprises the steps: collecting heart movie scanning data and electrocardio data of a time period corresponding to the heart movie scanning data under a preset scanning time sequence; reading and performing phase recovery processing on the cardiac movie scanning data to obtain a corrected k space data set; recording R wave trigger point moments corresponding to the R wave peak values; determining a specific position of the R-wave trigger point moment in the k-space data set based on the trigger point moment and a preset scanning time sequence; establishing a mapping relation table according to the acquisition sequence and the specific position of each data acquisition section in the k-space data set, and reordering each data acquisition section to form an ordered k-space data set; and synthesizing the ordered k-space data set by adopting a view sharing technology to obtain a complete k-space data set. The method has the effects of improving the cardiac film imaging quality and guaranteeing accurate reconstruction of the cardiac cycle.

The application discloses a kind of fast high-resolution multi-parameter quantitative magnetic resonance imaging method and system, comprising: design fast high-resolution multiple echo imaging pulse sequence;Determine the sampling parameter of pulse sequence;Construct the deep neural network for multi-parameter quantitative magnetic resonance image reconstruction;Generate the training sample of deep neural network;Using training sample, the trained deep neural network is obtained by training deep neural network;Using pulse sequence is scanned under the set sampling parameter to entity imaging object, and the k space data of entity imaging object is obtained;The k space data of the entity imaging object is preprocessed, and the image domain data of the entity imaging object is obtained;The image domain data of the entity imaging object is input into trained deep neural network and is reconstructed, and high-resolution multi-parameter quantitative magnetic resonance image is obtained.The application can realize fast high-resolution multi-parameter quantitative magnetic resonance imaging, and can resist the image distortion caused by main magnetic field inhomogeneity.