12 results about "Radial sampling" patented technology

The invention discloses a magnetic resonance non-enhanced lower limb arteriovenous combined imaging method, which belongs to the technical field of medical imaging, and comprises the following steps: S1, judging acquisition times and carrying out first acquisition, S2, setting delay time of data acquisition, S3, configuring a rapid interruption steady state and carrying out data acquisition, S4, repeating the steps S1 to S3 until all regions finish a data collection process of the first acquisition, the method comprises the following steps of S1, carrying out first acquisition, S2, carrying out second acquisition, S5, switching to second acquisition, judging the number of acquisition times, and carrying out second acquisition, S6, carrying out data acquisition by using the same process as S2 and S3, S7, repeating the steps S5 and S6 until all regions complete data collection of the second acquisition, and S8, carrying out image reconstruction to obtain an arteriovenous separation image. By fusing the fast interruption steady-state sequence and the golden angle radial sampling track, lower limb artery and vein synchronous high-contrast imaging is achieved under the condition that electrocardio gating is not needed.

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.

This application discloses a magnetic resonance chemical exchange saturation transfer imaging method, system, device, and storage medium. The method includes: applying a radio frequency saturation pulse for a first preset time to a region to be detected; applying a radio frequency echo pulse to the region to be detected and acquiring several gradient echo signals generated after activation by the radio frequency echo pulse; and using radial sampling to read the gradient echo signals along a preset direction to generate a magnetic resonance image. Through this method, this application effectively shortens the signal acquisition time by using gradient echo readings, effectively suppresses motion artifacts by using radial acquisition, and applies post-processing methods such as fitting to the acquired chemical exchange saturation transfer imaging spectral data to achieve water-lipid signal separation and extract and analyze the target signal.

The application relates to the technical field of medical imaging, and discloses a magnetic resonance imaging spiral acquisition method, device, equipment and storage medium, the method comprising the following steps: acquiring a long side and a short side of a rectangular field of view; determining a radial field of view and a circumferential field of view of spiral acquisition based on the long side and the short side of the rectangular field of view; the product of the radial field of view and the circumferential field of view is equal to the product of the long side and the short side of the rectangular field of view; determining a radial sampling interval and a circumferential sampling interval that satisfy the Nyquist sampling law based on the radial field of view and the circumferential field of view; determining a magnetic field gradient function based on a preselected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, a maximum gradient amplitude limit and a maximum gradient change rate limit; exciting a magnetic resonance signal in an imaging region based on the magnetic field gradient function, and acquiring the magnetic resonance signal. The spiral trajectory design scheme provided by the application can be applied to the acquisition density requirement of the rectangular field of view.

The application discloses a kind of magnetic resonance non-enhanced lower limb arteriovenous combined imaging method, belong to medical image technology field, including S1, judging acquisition times, and carrying out first acquisition, S2, set the delay time of data acquisition, S3, configure fast interrupt steady state, and carry out data acquisition, S4, repeat S1-S3 until all regions are completed first acquisition Data collection process, S5, switch to second acquisition, and judge acquisition times, and carry out second acquisition, S6, using the same process as S2 and S3 carries out data acquisition, S7, repeat S5 and S6 until all regions are completed second acquisition Data collection, S8, image reconstruction is carried out, and the arteriovenous separation image map is obtained, the application uses above-mentioned method, by fusing fast interrupt steady state sequence and golden angle radial sampling track, realize lower limb arteriovenous synchronous high contrast imaging under the condition of not needing electrocardiogram control.

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 application discloses a lung nodule medical image segmentation method based on nodule symmetry constraint, and relates to the technical field of medical image processing. The method comprises the following steps: after the CT data is preprocessed, features are extracted and a nodule center is predicted by using a deep network; based on the center, differentiable radial sampling is performed, a radial feature sequence is constructed, and boundary radii in each direction are predicted; a radius consistency loss and an opposite profile consistency loss are calculated, a symmetry mask is constructed, and the symmetry mask is fused with a basic segmentation response; finally, thresholding and center-based connected domain extraction are performed to output a final mask. By explicitly embedding a geometric morphological prior in the network, the radial symmetry of the nodule is utilized to effectively distinguish blood vessels from nodules, the problems of lacking geometric constraints, being prone to misjudgment of blood vessels and relying on complex post-processing in the prior art are solved, and end-to-end high-precision lung nodule segmentation is realized.

This invention relates to the field of biometric recognition software and image pattern analysis technology, and discloses an automatic extraction method for preoperative image features of uterine fibroids using focused ultrasound ablation for re-pregnancy assessment. The method includes: acquiring image voxel data of the target entity and calculating its geometric center; traversing candidate anchor points in a three-dimensional neighborhood space and identifying gradient maxima to determine the optimal sampling origin; emitting a spatial sampling vector from the optimal sampling origin to establish a radial sampling field; calculating the gradient and energy characteristics at interface attribute transitions; and fusing them after noise component stripping to generate a descriptor vector. This invention utilizes dynamic optimization of the sampling origin to achieve orthogonal alignment between the sampling path and the tissue interface, suppressing non-pathological diffusion of signal steps at the mechanistic level, and improving the accuracy and uniqueness of biometric descriptors in representing the physical integrity of tissues.

According to some embodiments, a method comprises obtaining a group of reconstructed-image data; converting the group of reconstructed-image data to a derivative of Radon space, thereby generating Radon-space data, wherein the Radon-space data have a radial sampling pattern in the derivative of Radon space; and generating resampled data by inputting the Radon-space data into a first trained machine-learning model for resampling Radon-space data, wherein the resampled data have a cone-beam-projection-geometry-shaped sampling pattern in the derivative of Radon space.

This invention discloses a method and system for detecting abdominal ultrasound in pets based on image analysis, belonging to the field of pet abdominal ultrasound image processing technology. This method maps the ultrasound image to the complex frequency domain using a two-dimensional fast Fourier transform, extracting the spatial phase spectrum. Using the zero-frequency center point as the origin of the emission point, low-frequency components of the solid organ contours are filtered out. Non-axial radial sampling rays are traversed within a preset high-frequency band, extracting the phase value sequence and calculating the autocorrelation coefficient. The feature direction angle corresponding to the maximum value is retrieved. A two-dimensional Gaussian filter mask is constructed based on this, and it is multiplied element-wise with a two-dimensional complex frequency domain matrix to specifically reduce physical grid stripe noise in that direction. Finally, a two-dimensional inverse Fourier transform is used to restore the image to the spatial domain and reconstruct an edge suppression feature map, which is then input into a machine learning model to output an auxiliary probability report of the lesion. This invention specifically filters out structured physical grid noise caused by residual hair roots in pets, significantly improving the accuracy of lesion identification.

The application provides a motion self-correcting kidney chemical exchange saturation transfer imaging method and system, belongs to the CEST imaging technical field, and the imaging method comprises the following steps: collecting an original image, dividing a respiratory state, reconstructing an image, image registration and fusion, data post-processing and signal quantification, and the imaging system comprises various modules for realizing the imaging method; through CEST sequence design of 112.5° radial sampling, k-space reading of fast field echo (TFE) is utilized, the signal of 0.1-0.5 Hz at the center of k-line is extracted as a respiratory signal, the respiratory state is divided by using the respiratory signal and k-space data is split, the images corresponding to different respiratory states are reconstructed, finally, the final CEST-MRI image is obtained through image registration and average fusion of the images of different respiratory states, the signal-to-noise ratio, saturation efficiency and signal accuracy are ensured, and the problem that the respiratory motion influences CEST signal quantification when chemical exchange saturation transfer imaging (CEST-MRI) of the kidney is performed under free breathing is solved.

The application relates to an anti-eddy current method for realizing MRI radial imaging, comprising the following steps: determining a radial direction angle of radial sampling in each repetition time, and applying an in-plane readout gradient according to the direction to obtain a target amplitude of the in-plane readout gradient; first performing gradient climbing; performing gradient stabilization time to keep the gradient constant; applying a radio frequency pulse, and opening an ADC sampling window near a spin echo center to collect signals, and keeping the in-plane readout gradient constant as the target amplitude during the collection. The anti-eddy current method for realizing MRI radial imaging, the device, the processor and the computer readable storage medium thereof can improve time utilization efficiency and shorten echo time TE, reduce the time occupied by the gradient climbing process, make the ADC sampling window closer to the echo center, improve the proportion of effective sampling time, realize shorter minimum echo time TE, and improve detection capability.