21 results about "Fat suppression" patented technology

Systems and methods are provided for estimating a navigation map for multi-shot phase navigation image reconstruction. Techniques described herein include acquiring a reference image of a subject, calculating a navigation map for a multi-shot MR image of the subject using the reference image, and reconstructing the multi-shot MR image by applying the navigation map to segments of the multi-shot MR image. The MR image and the reference image may be, for example, a T1 weighted image, a T2 weighted image, a liquid attenuation inversion recovery (FLAIR) image, a DWI image, a water separation image, a fat separation image, a fat suppression image, a phase contrast image, or a blood contrast image. The reference image may be of a different type than the MR image, and / or acquired from the same or different sequence as the MR image. The navigation map may correct for motion-induced phase differences of excitation variations in the multi-excitation MR image.

Provided in the present invention are a magnetic resonance imaging system and method. The magnetic resonance imaging method comprises: performing m NEXs, wherein in each NEX, a plurality of fat suppression pulses are applied, each of the plurality of fat suppression pulses has thereafter m gradient recalled echo sequences, and each NEX acquires q groups of initial image data, where q=m*n, n is the number of fat suppression pulses applied in each NEX, n is greater than 1, and m is greater than 1; and reconstructing a magnetic resonance image on the basis of at least a portion of the initial image data acquired in the m NEXs.

The invention relates to magnetic resonance, MR, imaging, comprising: subjecting one portion of an object (10) to a preparation sequence (PRE) comprising a spectrally selective adiabatic inversion radiofrequency, RF, pulse (21) having a flip angle (a) to selectively invert nuclear magnetization associated with fat protons; after a delay time (TD), subjecting the portion to an imaging sequence (IM) comprising one excitation RF pulse (28) to generate MR signals (27), wherein the delay time and / or the flip angle are determined such that contributions from a first spectral species of fat protons affected by the inversion RF pulse and a second spectral species of fat protons not affected by the inversion RF pulse to the MR signals substantially cancel each other out; acquiring the MR signals; and reconstructing an MR image from the MR signals, wherein contributions from both the first and second spectral species of fat protons are suppressed in the MR image.

The application discloses a uterus tumor differential diagnosis method and system based on multi-parameter MRI imaging and belongs to the technical field of medical image processing and artificial intelligence diagnosis. The method aims at the problems existing in the current uterus tumor MRI diagnosis, such as strong subjective dependence, insufficient utilization of multi-parameter information, unreasonable feature screening and model construction. The method comprises the following steps: collecting T1WI, T2WI, T2 fat suppression sequence and DWI multi-parameter images; after format standardization, deartifacting and Z-score normalization, a model combining U-Net and attention mechanism is used to realize automatic segmentation of the lesions; multi-dimensional features are extracted and the optimal subset is screened by ANOVA filtering-RFE-SVM packaging method; a stacking integrated model is constructed for training, and the output includes the differential results and confidence of ordinary uterine fibroids, special type uterine fibroids and uterine sarcoma; the application integrates multi-parameter complementary information, improves the segmentation efficiency and feature quality, has strong model generalization ability and accurate diagnosis, is suitable for the actual situation of the scarcity of uterine sarcoma cases, and provides an objective diagnosis tool for clinical use.

The invention discloses a small kidney tumor preoperative diagnosis method, system, medium and device based on MRI, and belongs to the field of medical imaging diagnos.The method comprises the steps that clinical feature data and original MR I image data of a patient to be diagnosed and MRI interpretation feature data obtained through interpretation based on the original MRI image data under the blind method condition are obtained; performing tumor region segmentation in the original MRI image data to generate tumor three-dimensional volume-of-interest data; extracting a radiomics feature set from a non-fat suppression T2 weighted imaging sequence and a contrast enhancement T1 weighted imaging sequence in the original MRI image data based on the tumor three-dimensional volume-of-interest data, and performing weighted fusion calculation on each feature in the radiomics feature set to obtain a radiomics score; and inputting the clinical feature data, the MR I interpretation feature data and the radiomics score into a preset composite diagnosis model for diagnosis, and outputting a diagnosis result. By implementing the method, the accuracy of benign and malignant identification before the small kidney tumor operation can be improved.

A computer-implemented method for suppressing fat in reconstructed magnetic resonance imaging data includes generating, via a processor, a first echo image and a second echo image from magnetic resonance scan data acquired of a subject with a magnetic resonance scanner utilizing a multi-echo steady state sequence. The computer-implemented method also includes estimating, via the processor, an echo phase difference between the first echo image and the second echo image to generate an echo phase difference image. The computer-implemented method further includes identifying, via the processor, voxels in the echo phase difference image having an extra chemical shift phase. The computer-implemented method even further includes removing, via the processor, signals of the voxels identified having the extra chemical shift phase in both the first echo image and the second echo image to generate a first fat-removed image and a second fat-removed image, respectively.

The present disclosure relates to a magnetic resonance diffusion imaging fat suppression method based on echo navigation water-fat separation, comprising: acquiring echo and / or navigation echo corresponding to multiple chemical shift encoding points under the condition that the b value is equal to 0 and the condition that the b value is greater than 0; solving the water map, the fat map, the main magnetic field inhomogeneity and the relaxation time of the target object under the condition that the b value is equal to 0, and determining the water map and the fat map of the target object under the condition that the b value is greater than 0. Through the present disclosure, a chemical shift encoding fat suppression method suitable for clinical use is provided for magnetic resonance EPI diffusion imaging, the interference of fat chemical shift artifacts is reduced, the accuracy of image contrast and quantitative parameter measurement is improved, the universality of chemical shift encoding EPI DWI is improved, and the image reconstruction speed and robustness are accelerated.

This invention provides a magnetic resonance imaging (MRI) apparatus and its control method. In contrast-enhanced MRI, it improves the ability to depict tissues reached by the contrast agent and shortens the overall imaging time. The imaging unit of the MRI apparatus is equipped with a gradient echo pulse sequence for acquiring T1-emphasis images containing fat-suppressing pulses. The control unit performs the following control: the imaging unit repeats the pulse sequence for a given time from the time the contrast agent is administered to the subject, generating images of multiple phases at different arrival locations of the contrast agent. At this time, starting from the phase about to reach the target tissue, a preparatory pulse is added before the pulse sequence to suppress signals from the contrast agent present outside the target tissue (cells).

The disclosed technology relates to a method and device for generating a fat-suppressed magnetic resonance image, the method comprising: a step of inputting a magnetic resonance image into an encoder of a neural network to extract features of the magnetic resonance image by an image device; and a generator of the neural network generating a T2-weighted fat-suppressed image based on the features, wherein, before inputting the magnetic resonance image, the neural network learns based on a result of a discriminator of the neural network discriminating a loss caused by the generation of the T2-weighted fat-suppressed image and a result of a decoder reconstructing the magnetic resonance image input to the encoder using Bloch equations.

A system and method are provided for acquiring diffusion weighted imaging (DWI) images of a subject using a magnetic resonance imaging system includes performing a chemical-shift encoded (CSE) prescan of a subject to generate a fat image, a water image, and a B0 field map. The method also includes, for each slice or volume of a desired (DWI) acquisition from the subject, determining shim parameters that improve water signal and suppress fat signal. The method further includes performing the DWI acquisition to acquire DWI data form the subject using the shim parameters and reconstructing DWI images of the subject with suppressed artifacts induced by fat of the subject.

The present disclosure relates to systems and methods for multi-echo steady-state sequences with improved fat suppression using adaptive DIXON techniques. A computer-implemented method for suppressing fat in reconstructed magnetic resonance imaging data includes generating, via a processor, a first echo image and a second echo image from magnetic resonance scan data of a subject acquired by a magnetic resonance scanner using a multi-echo steady-state sequence; the computer-implemented method also includes estimating, via the processor, an echo phase difference between the first echo image and the second echo image to generate an echo phase difference image. The computer-implemented method also includes identifying, via the processor, voxels in the echo phase difference image having additional chemical shift phases. The computer-implemented method even further includes removing, via the processor, signals of voxels identified as having additional chemical shift phases in both the first echo image and the second echo image to generate a first fat removal image and a second fat removal image, respectively.

The invention relates to magnetic resonance, MR, imaging, comprising: subjecting one portion of an object (10) to a preparation sequence (PRE) comprising a spectrally selective adiabatic inversion radiofrequency, RF, pulse (21) having a flip angle (a) to selectively invert nuclear magnetization associated with fat protons; after a delay time (TD), subjecting the portion to an imaging sequence (IM) comprising one excitation RF pulse (28) to generate MR signals (27), wherein the delay time and / or the flip angle are determined such that contributions from a first spectral species of fat protons affected by the inversion RF pulse and a second spectral species of fat protons not affected by the inversion RF pulse to the MR signals substantially cancel each other out; acquiring the MR signals; and reconstructing an MR image from the MR signals, wherein contributions from both the first and second spectral species of fat protons are suppressed in the MR image.

The embodiment of the invention discloses a fat pressing parameter determination method, device and system applied to arterial spin labeling imaging. The method comprises the following steps: according to an acquisition parameter set adopted by the ASL imaging, determining the longitudinal magnetization intensity of fat when a first fat pressing pulse for the ASL imaging begins to be applied; according to the longitudinal magnetization intensity of the fat when the first fat suppression pulse begins to be applied, the overturning angle or overturning duration TI of the first fat suppression pulse is determined, so that the longitudinal magnetization intensity of the fat when the first excitation pulse of the ASL imaging begins to be applied is the expected longitudinal magnetization intensity. According to the embodiment of the invention, accurate acquisition of the overturning angle or the TI of the fat pressing pulse is realized, and the accurate overturning angle and the TI are selected for the fat pressing pulse applied to ASL imaging, so that the ASL imaging quality is finally improved, and fat ghosting in an ASL image is reduced.

The invention relates to a magnetic resonance imaging method and a magnetic resonance imaging system, and the method comprises the steps: obtaining an initial inversion recovery scanning sequence which comprises an inversion module and an imaging collection module; obtaining first gradient coding position information of a set tissue of the target scanning part according to an imaging acquisition module; according to the first gradient coding position information, gradient coding parameters of an inversion module are determined, and a target inversion recovery scanning sequence is obtained; and scanning the target scanning part according to the target inversion recovery scanning sequence to obtain a magnetic resonance image. By adopting the method, the problem that a fat inhibition method cannot have a relatively good inhibition effect in various occasions can be solved.

The application provides a magnetic resonance imaging method, device, electronic equipment and storage medium. The method comprises: acquiring a plurality of scan selected layers of a target human body; for each diffusion direction, after performing a target operation corresponding to the diffusion direction on each scan selected layer, applying a signal acquisition window to the scan selected layer to obtain an imaging signal of the scan selected layer corresponding to the diffusion direction; and based on the imaging signal of the scan selected layer corresponding to the diffusion direction, performing image reconstruction to obtain a magnetic resonance diffusion weighted image of the scan selected layer corresponding to the diffusion direction. The application can reduce the pressure on the magnetic resonance system (in the gradient power amplifier coil) by advancing the application time of the eddy current elimination gradient, and in addition, the eddy current elimination gradient in the application can also disperse the fat suppression pulse additionally applied to suppress the generation of fat signals, further reducing the interference on the acquired imaging signal, thereby greatly reducing the deformation of the diffusion weighted image.

Image processing methods and methods and systems for generating a motion phase map for multi-shot magnetic resonance image reconstruction are provided. Systems and methods for estimating a navigation map for multi-shot phase navigation image reconstruction are also provided. Techniques described herein include acquiring a reference image of a subject, calculating a navigation map for a multi-shot MR image of the subject using the reference image, and reconstructing the multi-shot MR image by applying the navigation map to segments of the multi-shot MR image. The MR image and the reference image may be, for example, a T1 weighted image, a T2 weighted image, a liquid attenuation inversion recovery (FLAIR) image, a DWI image, a water separation image, a fat separation image, a fat suppression image, a phase contrast image, or a blood contrast image. The reference image may be of a different type than the MR image, and / or acquired from the same or different sequence as the MR image. The navigation map may correct for motion-induced phase differences of excitation variations in the multi-excitation MR image.

The invention relates to a fat pressing method and device for magnetic resonance diffusion imaging based on water-fat separation, and the method comprises the steps: adjusting the bandwidth corresponding to a target excitation pulse and a target refocusing pulse, so as to change the position of a main peak fat layer excited and refocused in initial magnetic resonance imaging, and inhibit the main peak fat; moving a preset signal reading window to collect diffusion and non-diffusion imaging signals of single excitation or multiple excitation corresponding to the signal reading window at different moving time; constructing a corresponding diffusion imaging signal model, simplifying the diffusion imaging signal model, solving the non-diffusion imaging signal model through a water-fat separation algorithm to obtain a water graph, a fat graph, a magnetic field non-uniformity graph and a relaxation time graph corresponding to the non-diffusion imaging signal model, and calculating a coil sensitivity graph corresponding to the non-diffusion imaging signal model; and solving a diffusion imaging signal model to obtain a diffusion-weighted water map, a fat map and a phase difference between excitation so as to finish inhibition of olefin peak fat.

Phase-sensitive water-fat separation magnetic resonance imaging (MRI) includes acquiring k-space data with an MRI system. The k-space data are acquired at echo times (TEs) at which water spins and fat spins are at least partially out-of-phase with each other. One or more TE images are reconstructed from the k-space data. A background phase is estimated from the TE image(s). One or more phase-corrected images are generated by performing phase correction on the TE image(s) using the background phase. Separated water images and fat images are generated from the phase-corrected image(s). At least one set of the water images or the fat images are then output.

The invention discloses a high-B-value diffusion fat suppression image quality improvement method and a magnetic resonance imaging system. The method comprises the following steps: designing a water excitation pulse; designing a narrow bandwidth frequency fat pressing pulse; constructing a dispersion sequence of the combined fat pressing mode; according to the method, a high B value dispersion image is obtained, most fat signals in the high B value dispersion image can be successfully inhibited by utilizing the characteristic that the water excitation pulse is insensitive to the uniformity of a B1 field, and the fat pressing effect of the dispersed high B value image in 3.0 T magnetic resonance can be improved by combining two narrow bandwidth frequency fat pressing pulses and performing supplementary inhibition on missing fat signals.

The present invention proposes a percutaneous lumbar disc puncture surgical navigation method and device based on multimodal images. The method includes: obtaining preoperative MR images and CT images, sequentially inputting a multi-contrast multimodal image segmentation model and a multimodal image rigid-elastic hybrid registration model to obtain a first registration image; based on the intraoperative three-dimensional CBCT image, calling the multi-contrast multimodal image segmentation model and the multimodal image rigid-elastic hybrid registration model again to obtain a second registration image; and constructing a three-dimensional visualization model of the spine based on the second registration image and generating a puncture navigation path. According to the technical solution of the embodiment of the present invention, it is possible to automatically align the surgical MR image, CT image, and intraoperative three-dimensional CBCT image using a mask, introduce two sequences, fat suppression and non-fat suppression, into the preoperative MR image, so that the second registration image can distinguish between bone, flesh, and spinal structure, thereby improving the accuracy of the three-dimensional visualization model of the spine, and improving the accuracy of the navigation path and the feasibility of the surgery.

Systems and methods for estimating navigator maps for multi-shot phase-navigated image reconstruction are provided. The techniques described herein include acquiring a reference image of a subject, calculating, for a multi-shot MR image of the subject, a navigator map using the reference image, and reconstructing the multi-shot MR image by applying the navigator maps to segments of the multi-shot MR image. The MR image and the reference image may be, for example, a T1-weighted image, a T2-weighted image, a fluid-attenuated inversion recovery (FLAIR) image, DWI image, a water separated image, fat separated image, a fat suppressed image, a phase contrasted image, or a blood contrasted image. The reference image may be a different type, and / or acquired from the same or a different sequence than the MR image. The navigator maps may correct for shot-varying motion-induced phase differences in the multi-shot MR image.