83 results about "Diffusion imaging" patented technology

A system determines motion correction data for use in diffusion MR imaging using an RF signal generator and magnetic field gradient generator which sequentially acquire in a single first direction through a volume, first and second slice sets individually comprising multiple individual diffusion image slices. The first set of slices and the second set of slices are spatially interleaved within the volume, by providing in acquiring the second slice set, a low flip angle RF pulse successively followed by a non-diffusion image data readout magnetic field gradient for acquisition of data representing a two dimensional (2D) non-diffusion image used for motion detection of the first slice set successively followed by, a first diffusion imaging RF pulse followed by a first diffusion imaging phase encoding magnetic field gradient for preparation for acquiring data representing a diffusion image slice of the second slice set.

The invention discloses a diffusion magnetic resonance imaging and reconstruction method. The method includes the steps of S1, using multiple channel coils and adopting a multi-excitation diffusion imaging mode to carry out signal acquisition on tested targets to obtain k spatial data; S2, calculating a coil sensitivity figure and carrying out iterative initialization; S3, conducting iterative reconstruction on needed diffusion images on the basis of the POCS algorithm according to the collected k spatial data, the coil sensitivity figure obtained through calculation and initialization parameters. According to the method, not only is acquisition efficiency of signals improved, but also fuzzy artifacts and motion artifacts of the images are reduced, and image resolution is improved.

A method for eliminating then on-MG component in RARE imaging that does not require a poor slice profile or discarding a substantial number of echoes (FIG. 2). This method relies upon the observation that the magnetization in each component is determined by the phase at one half of the echo time before the first refocusing pulse. A ninety degree pulse applied at this time will rotate one of the components to the longitudinal axis where it will be invisible in the subsequent sequence, (b RF). If the phase of the ninety degree pulse is the same as that of the refocusing pulses, then it will be the non-MG component that is eliminated. The combination of the tailored RF train and this ninety degree pulse permits acquisition of data from the very first echo without artifact (FIGS. 2, 4).

In a method and magnetic resonance apparatus to reduce distortions in magnetic resonance diffusion imaging, a magnetic resonance data acquisition system is operated to acquire magnetic resonance data in a first measurement with a first diffusion weighting, and to acquire magnetic resonance data in a second measurement with a second, different diffusion weighting. A non-linear, system-specific distortion-correcting function is determined on the basis of system-specific information that is specific to said magnetic resonance data acquisition system. Correction parameters are calculated to correct distortions in subsequently-acquired diffusion-weighted magnetic resonance images, based on the data acquired in the first and second measurements with the system-specific distortion-correcting function applied thereto. The subsequently-acquired diffusion-weighted magnetic resonance images are corrected using the correction parameters to at least reduce distortions therein.

The invention provides a single-scanning quantitative magnetic resonance diffusion imaging method based on dual echo, and relates to a magnetic resonance imaging method. According to the method, two echoes with the same evolution time are generated through two small-angle excitation pulses with the same turning angle, so that the same transverse relaxation time is achieved; a displacement gradient is added after each excitation pulse to achieve central displacement of the two echo signals in a signal space, and a diffusion gradient is added after the first excitation pulse, so that diffusion reduction only exists in the first echo signal; accordingly, signals under different diffusion factors are obtained. The two echo signals are from one imaging slice, so that the two echo signals can be separated through priori knowledge of the two echo signals by matching sparse conversion with a corresponding separation algorithm. Finally, a quantitative ADC image is obtained by performing apparent diffusion coefficient calculation on two signals obtained through separation. Single-scanning quantitative ADC imaging is obtained through the method, and the quality of the obtained ADC image is good.

In a method and magnetic resonance (MR) system for correction of image distortions that occur in acquisitions of diffusion-weighted MR images of an examination subject a first adjustment measurement with a first diffusion weighting is implemented, a second adjustment measurement with a second diffusion weighting is implemented and correction parameters to de-skew diffusion-weighted MR images are automatically calculated in a computer on the basis of the two adjustment measurements. One of the two adjustment measurements is implemented with a predetermined diffusion weighting in three orthogonal diffusion directions, and correction parameters are determined for the three orthogonal diffusion directions.

In a method for correction of distortions in image data in a diffusion imaging, the image data are acquired with an imaging MRT measurement for a predetermined diffusion weighting and map a predetermined image segment. A diffusion model for the image segment is determined. Output image data are determined for the image segment such that the output image data are essentially free of distortions caused by diffusion weighting. Reference image data are estimated for the predetermined diffusion weighting for the image segment based on the output image data and the diffusion model. The acquired image data are compared with the reference image data and the acquired image data are corrected based on the comparison.

The invention relates to multi-access near infrared light diffusion imaging system of brain functional research, which belongs to medical equipment technological field, comprising of near infrared light laser source, multi-access optical fiber switcher, reflected sensing head with multi-light source and multi-detector, electro optical signal collecting and magnifying circuit system, computer with data collection card and program or controlling signal collection and imaging. The sensing head is reflected sensing head with multi- light source and multi-detector, with a rectangular slice made of soft material as substrate; the light source and detector arrange according to the way of rectangular array, each detector light source is embedded in the central point of rectangular area formed by four light sources or switcher adjacent. Besides, the invention uses the way of contrast imaging, eliminating the effect caused by mismatching between the access, and it doesn't bring hurt, pocketable and stable, also, it can realize real time dynamic imaging which is easier to understand, suitable for clinical application.

A thin section fabrication apparatus includes an epi-imaging data acquisition unit that performs imaging by radiating epi-illumination and acquires imaging data, a diffusion imaging data acquisition unit that performs imaging by radiating diffusion illumination and acquires imaging data, an exposed shape extraction unit that extracts an exposed shape of an exposure portion of the biological sample which is exposed to a surface of the embedding block, based on the imaging data acquired by the epi-imaging data acquisition unit, an embedded shape extraction unit that extracts an embedded shape of an embedding portion of the biological sample which is embedded in the embedding block, based on the imaging data acquired by the diffusion imaging data acquisition unit, and a control unit that determines ending of the preliminary cutting by comparing the exposed shape extracted by the exposed shape extraction unit and the embedded shape extracted by the embedded shape extraction unit.

The invention discloses a magnetic resonance diffusion imaging method for integration and reconstruction based on a Gaussian diffusion model acting as an instance. The method comprises the steps that signal acquisition is performed on a tested target based on multilayer simultaneously excited preset sequences; phase estimation is performed on the acquired under-sampled signals through a parallel imaging technology; the Gaussian diffusion model is established through the estimated phase, the acquired under-sampled signals and a reference image without diffusion weight; the under-sampled signals of all the directions are integrated according to the Gaussian diffusion model, and a target equation is established; the target equation is iteratively solved by using a nonlinear conjugate gradient algorithm so as to obtain a diffusion tensor parameter; and a diffusion coefficient and a diffusion weight image are calculated according to the diffusion tensor parameter. Therefore, high acceleration acquisition of magnetic resonance diffusion tensor imaging can be realized so that the acquisition time can be effectively reduced, the diffusion tensor parameter can be accurately estimated to obtain the diffusion image of high signal-to-noise ratio and high resolution, and the requirement of clinical application can be met.

The invention belongs to the field of resonance diffusion imaging, in particular to a fast-marching fiber tracking method based on topology preservation, comprising the steps of: reading DTI (Diffusion Tensor Imaging) data; manually selecting a seed point and initializing; evoluting from the seed point to peripheral neighbor points by using a fast-marching method and adopting a curvature weighting speed function, recording topology information in an evolution process, i.e. a source node of each evoluting point; calculating all paths by adopting a time gradient descent method; and selecting a real fiber path by a link matrix. The invention has the advantages of more according with the real fiber path by fiber tracking and reducing urious positive branches; and the obtained fiber is smooth and better reflects the fiber direction.

The invention discloses a signal processing method and device for intravoxel incoherent motion imaging and a storage medium. The method includes the steps of setting non-zero b value distribution, conducting IVIM dispersion imaging magnetic resonance scanning on each b value based on an MRI scanner, and outputting images corresponding to the b values, wherein the b values are related to the intensity of a diffusion imaging gradient magnetic field; conducting attenuation model fitting on each b value and a region of interest on the corresponding IVIM diffusion imaging image, and outputting IVIMparameters representing the relationship between the b values and the intensity of imaging signals. In the method, the images of the non-zero b values are adopted for fitting, the fitting difficultyis reduced, the calculation result is more stable, the relationship between the intensity of the diffusion imaging gradient magnetic field and the image signals can be easily reflected, and extensiveuse in clinical medicine is facilitated.

In a method and magnetic resonance (MR) system for correction of image distortions that occur in acquisitions of diffusion-weighted MR images of an examination subject a first adjustment measurement with a first diffusion weighting is implemented, a second adjustment measurement with a second diffusion weighting is implemented and correction parameters to de-skew diffusion-weighted MR images are automatically calculated in a computer on the basis of the two adjustment measurements. One of the two adjustment measurements is implemented with a predetermined diffusion weighting in three orthogonal diffusion directions, and correction parameters are determined for the three orthogonal diffusion directions.

A method for extracting tissue fiber bundle structure information based on adaptive diffusion basis function decomposition, which belongs to the field of magnetic resonance diffusion imaging data processing. The purpose of the present invention is to more accurately extract tissue fiber structure information from acquired magnetic resonance diffusion weighted data . Method: 1. Construct a set of tensor basis functions of adaptive eigenvalues; 2. Express the diffusion weighted signal by the linear combination of the constructed tensor basis functions, and then list the diffusion weighted signal represented by the linear combination of tensor basis functions and the actual measured The minimum objective function of the error between diffusion weighted signals; 3. Use an iterative method to solve the weighted coefficients and eigenvalues ​​that minimize the value of the minimized objective function in step 2; 4. Perform the weighted coefficients and eigenvalues ​​obtained in step 3 After post-processing, the running direction of the fiber bundle in the voxel is obtained, which is completed. The advantage of the present invention is that the accuracy of extracting tissue fiber structure information from acquired magnetic resonance diffusion weighted data is high.

The invention discloses a 3D display device and a method. The device comprises an LED (light emitting diode) display used for displaying an image; a light path control structure of a multi-layer pinhole structure and used for controlling the light path emergent direction of the image so as to form the three-dimensional light field information; and a holographic function screen used for carrying out diffusion imaging on the three-dimensional light field information to form a 3D image. The LED display, the light path control structure and the holographic function screen are arranged in sequence. Each layer of the pinhole structure is provided with a plurality of groups of pinhole arrays. According to the invention, the technical problem of poor 3D effect in the prior art is solved.

The invention discloses an equal voxel magnetic resonance diffusion imaging method and an equal voxel magnetic resonance diffusion imaging device based on multi-plate simultaneous excitation, whereinthe method comprises the following steps: S1, performing excitation for a tested target for many times through multi-plate simultaneous excitation pulse, and in a process of excitation each time, performing signal acquisition for the tested target through a multi-channel coil, and thereby obtaining k space data acquired through down sampling in excitation each time; S2, by a multi-excitation diffusion imaging reconstruction algorithm uniting the k space and an image domain, recovering k space position data which is not sampled in excitation each time; S3, correcting edge artifacts through an improved NPEN algorithm, thereby obtaining an imaged image. The method can obtain high-resolution images and also can keep relatively high signal-to-noise ratio at the same time, can reduce interference of three-dimensional navigation echo errors and improve quality and stability of reconstructed images, and can improve signal-to-noise ratio efficiency and scanning efficiency on the basis of guaranteeing the quality of the images.

The invention provides a parameter error estimation method and device of magnetic resonance diffusion tensor imaging. The method comprises the steps that through magnetic resonance scanning, a diffusion weighted graph is collected; the diffusion tensor of each pixel point in the diffusion weighted graph is estimated according to the diffusion weighted graph; anisotropy coefficients and average diffusion coefficients are calculated according to the diffusion tensors; an error graph of the diffusion weighted graph is calculated; the errors of the diffusion tensors are calculated according to the diffusion tensors and the error graph of the diffusion weighted graph; the errors of the diffusion tensors, the anisotropy coefficients and the average diffusion coefficients are substituted into a preset parameter error calculation model to calculate and obtain the average diffusion coefficient errors and the anisotropy coefficient errors. According to the method and device, the distribution condition of the errors in a magnetic resonance diffusion imaging parameter graph can be visually expressed, and therefore image quality estimation of diffusion tensor imaging is facilitated.

In a magnetic resonance imaging system and operating method for generating magnetic resonance image data of an object under examination, in order to acquire magnetic resonance raw data, an operating sequence is determined that has an excitation wherein an RF excitation pulse is radiated, and a readout procedure for receiving RF signals. In addition, a diffusion contrast gradient pulse sequence is generated that includes an uneven number of 2n+1 diffusion contrast gradient pulses switched in chronological succession, with the sum of the zero gradient moments of the diffusion contrast gradient pulses having the value zero and the sum of the first gradient moments of the diffusion contrast gradient pulses having the value zero. An RF refocusing pulse is switched between two of the diffusion contrast gradient pulses.

The invention discloses a motion correction method for magnetic resonance multiple excitation diffusion imaging. The method comprises the steps of collecting a magnetic resonance multiple excitation sequence; obtaining an image echo signal and a two-dimensional navigation signal through a magnetic resonance scanning sequence; estimating motion parameters through the two-dimensional navigation signal; performing rotational and translational correction on the image echo signal and the two-dimensional navigation signal according to the motion parameters, and discarding tainted data, thereby obtaining corrected data; integrating the corrected data collected in multiple excitation to perform parallel imaging reconstruction; estimating rotational motion parameters through an image registration algorithm to perform diffusion gradient correction on a reconstructed image; and performing final calculation by utilizing corrected diffusion image and diffusion gradient to obtain diffusion tensor imaging parameters. According to the method, various motion errors in a magnetic resonance diffusion imaging scanning process can be effectively corrected, so that an artifact-free high-resolution diffusion tensor image is obtained, the errors are effectively reduced, and the accuracy of calculating magnetic resonance diffusion imaging tensor parameters is improved.

The invention discloses a head-up display system, which is used for vehicle navigation. The head-up display system includes an image generating device and a diffusion imaging unit. The image generating device is installed on the dashboard for generating visible light with image signals and sending out The diffuse imaging unit can be movably installed on the instrument panel and coupled with the image generating device to receive the visible light from the image generating device to form a solid image on the diffuse imaging unit. The head-up display system of the present invention simplifies the imaging system into an image generating device and a diffusion imaging unit movably connected to the image generating device, so the structure is simplified, the cost is reduced, and the angle of the projected image can be adjusted in good time according to the needs of the driver. .

The invention relates to a compressive sensing-based quick fine angular resolution diffusion imaging method which comprises the following steps of: confirming the distribution directions of diffusion sensitive gradient magnetic fields according to a spherical helix distribution mode; setting an undersampled coding strategy for the distribution direction of each confirmed diffusion sensitive gradient magnetic field; acquiring a set of k space signals of the distribution direction of the first diffusion sensitive gradient magnetic field to be taken as reference images in the manner of full-sampling; inputting the distribution directions of the other diffusion sensitive gradient magnetic fields and the undersampled coding strategy of the distribution directions into a magnetic resonance scanner, and sequentially acquiring k space signals of the distribution directions; respectively subtracting each set of obtained k space signals with the k space signals of the reference image, rebuilding by a compressive sensing method to obtain difference value images, and overlapping the difference value images onto the reference images. According to the method, the small amount of k space signals can be acquired by the helix distribution method, the undersampled coding strategy and the HARDI data characteristics, so that an unknown image can be well rebuilt; and therefore, the sampling speed and the image rebuilding speed can be accelerated.

The invention discloses a brand-new nuclear magnetic resonance echo mechanism based magnetic resonance imaging method. The method includes: turning dispersion-phase spins to a longitudinal plane, andsubstituting transverse relaxation with longitudinal relaxation to reduce signal relaxation attenuation; combining with a brand-new echo generating mechanism to obtain completely gathered echo on a transverse plane to keep signals as far as possible, so that a signal-to-noise ratio of an imaging sequence is substantially increased. The method has advantages that the defect of respective signal loss of traditional echo sequences (spin echoes and stimulated echoes) is overcome, optimal echo signals are formed, sequence schemes comprehensively superior to the spin echoes and the stimulated echoesare provided for echo sequence applying diffusion imaging and flow imaging, the signal-to-noise ratio of images is increased to obtain high-quality images, and accordingly an accurate and reliable quantitative measurement method is provided for magnetic resonance in bulk diffusion and flow imaging, and a promising application prospect in biological medical research and clinical diagnosis is achieved.

The invention relates to a method for reducing distortions in diffusion imaging, comprising the steps of: carrying out at least one first measurement (R1) with a first diffusion weight each for a plurality of spatially separated layers; A plurality of spatially separated layers each carry out at least one second measurement (R2) with a second diffusion weight; determining a distortion correction function and determining correction parameters from said measurements (R1, R2) for weighting the diffusion Distortion correction is performed on the magnetic resonance image of the MRI image, wherein the image information and / or correction parameters of different layers are correlated with each other; and the distortion correction of the diffusion-weighted magnetic resonance image is performed based on the distortion correction function and the correction parameter. Furthermore, the invention proposes a magnetic resonance system (1) that can be used to carry out such a method.

The invention discloses a comprehensive magnetic resonance imaging device. According to the invention, the cerebral function imaging, the MRI perfusion weighted imaging and the magnetic resonance diffusion imaging are united, so that the assessment for the cerebral injury caused by motor neuron disease and Parkinson disease is assisted, a beneficial judging basis is supplied for illness state judgment, and the accuracy rate of disease judgment is increased; an ALS (amyotrophic lateral sclerosis) patient is accompanied with FTD (frontal temporal dementia), so that the detection means, such as cortex thickness, also is beneficial to the disease diagnose and research; functional magnetic resonance imaging (fMRI) and diffusion tensor imaging techniques have strong complementarity; the combination of the functional magnetic resonance imaging and diffusion tensor imaging techniques has a wide application prospect in neurosciences research; unique brain structure and function information can be supplied.

Exemplary system, method and computer-accessible medium for determining a difference(s) between two sets of subjects, can be provided. Using such exemplary system, method and computer-accessible medium, it is possible to receive first imaging information related to a first set of subjects of the two sets of the subjects, receive second imaging information related to a second set of subjects of the two sets of subjects, generate third information by performing a decomposition procedure(s) on the first imaging information and the second information, and determine the difference(s) based on the third information.

A comprehensive analytical method for predicting early-stage Parkinson's disease comprises the following steps: S1, reading diffusion weighted magnetic resonance data DW-MRI, carrying out noise reduction and pre-smoothing processing on all the data, carrying out modeling and imaging and fiber tracking by applying diffusion tensor imaging and high angular resolution diffusion imaging technologies to acquire voxel fiber direction information, and calculating six types of brain fiber variation analysis index data; S2, extracting and marking special brain region voxel information, selecting a continuous region as a midbrain substantia nigra region by virtue of setting a threshold value of an anisotropic fraction, and then screening and extracting the index data in interested regions; and S3, carrying out comprehensive analysis by applying a SPSS analytical tool according to the six types of brain fiber variation analysis index data obtained by the step S2 to obtain a fiber variation result on the midbrain substantia nigra regions of a testee and a normal person so as to predict the sickness status of the testee. The method provided by the invention is high in resolution and accurate and reliable.

The invention discloses a navigation magnetic resonance diffusion imaging method and device based on multiple excitations. The method comprises the following steps of carrying out multiple excitations on a tested target, collecting a diffusion resonance signal, and collecting one-dimensional navigation data, wherein the one-dimensional navigation data are k space zero-crossing point data collected after multiple excitation imaging echoes; carrying out interpolation of adjacent k space points through a parallel imaging method, and recovering two-dimensional navigation information according to the one-dimensional navigation data; and correcting the phase of multiple excitation diffusion magnetic resonance imaging according to the two-dimensional navigation information to obtain a required image. The imaging method can reduce image deformation and improve the image resolution, can remove phase errors in multiple excitation diffusion imaging and artifacts generated by the phase errors, and can improve the image collection efficiency at the same time.