51 results about "Radial sampling" patented technology

A probe with an integral filtered vent and sampling port has a hollow shaft configured as a drill bit which in use passes through the lid of a drum containing waste products within a liner. The hollow shaft has a penetrating tip and at lest two radial bores, one of which is positioned to open to the space within the liner and the other of which is positioned to open to the space above the liner and between the liner and drum lid. The shaft has a head with a pocket which contains a filter element, the head also having a radial sampling port with a septa seal. In order to sample head space gases, a hypodermic needle is pushed through the septa seal into the longitudinal bore of the hollow shaft, and then withdrawn, allowing the septa seal to close behind the needle. The probe is especially useful for sampling nuclear waste stored within drums having liners. This is because the probe has a first radial port adjacent the penetrating tip thereof which samples gas within the liner and a second radial port disposed between the liner and lid for sampling gas which has escaped past the liner.

Exemplary method, system and computer-accessible medium can be provided which facilitates an acquisition of radial data, which can be continuous, with an exemplary golden-angle procedure and reconstruction with arbitrary temporal resolution at arbitrary time points. According to such exemplary embodiment, such procedure can be performed with a combination of compressed sensing and parallel imaging to offer a significant improvement, for example in the reconstruction of highly undersampled data. It is also possible to provide an exemplary procedure for highly-accelerated dynamic magnetic resonance imaging using Golden-Angle radial sampling and multicoil compressed sensing reconstruction, called Golden-angle Radial Sparse Parallel MRI (GRASP).

The invention discloses a fast and precise MRI (Magnetic Resonance Imaging) reconstruction method. The method comprises steps: scanning is carried out in a target visual field to obtain K space full sampling data; the K space full sampling data are sampled by using radial sampling to obtain under sampling data; the under sampling data are subjected to multi-loop data recovery to obtain an MRI image; and double-density dual-tree complex wavelet transform is used as a sparse basis, and according to the priori information of the MRI image under the double-density dual-tree complex wavelet transform, an FISTA algorithm is combined for image reconstruction. The reconstruction method can better depict image details and information, and the quality of the recovered image is improved.

The contrast of an image captured by imaging using a multi-echo sequence by radial sampling is improved.

Images are simultaneously captured by using a multi-echo sequence by radial sampling, and echo signal groups of one or more blocks measured by executing the imaging using the multi-echo sequence are divided into a plurality of partial echo signal groups.

Using the partial echo signal groups, images with different contrasts are reconstructed.

The invention discloses a method and device for processing radar echo sampling data. The method includes the following steps that when a frame of radar echo sampling data is received, according to the number of radial sampling points of the radar echo sampling data and the number of peripheral sampling points of the radar echo sampling data, bilinear interpolation is conducted in the radial direction and/or the circumference direction to supplement missing sampling points, and according to rounding errors, an interpolation threshold compensation method is provided. The device includes an interpolation threshold compensation module, an inhibition image flashing module and an echogram display module. By means of the method and the device, an effective solution is provided for image display leaking point compensation, image flickering and satellite map overlay positioning and other problems in digital echo display in the prior art, the speed is high and the implementation efficiency is high.

An exemplary system, method and computer-accessible medium can be provided for generating an image(s) of a tissue(s) that can include, for example, receiving magnetic resonance imaging information regarding the tissue(s) based on a golden-angle radial sampling procedure, sorting and synchronizing the MRI information into at least two dimensions, and generating the image(s) of the tissue(s) based on the sorted and synchronized information. The tissue(s) include cardiac tissue and respiratory-affected tissue. The MRI information can include a motion of the cardiac tissue and a motion of the respiratory tissue.

The invention discloses a myocardium T1 quantifying method. The method includes the steps that after electrocardiograph gating trigger delay, non-layer-selection inversion pulses are applied; real-time interlaced collection of at least two layers of images is carried out with a fast spoiled gradient echo low-angle shot sequence of a radial sampling trajectory, and the inversion recovery process of signals is captured; a sampling line in diastole is selected to serve as a K space center line; with the selected sampling line as the center, the sampling line is symmetrically selected to carry out image reconstruction according to the size of a reconstruction window; a T1 quantifying graph is fitted with restructured images. The invention further discloses a device based on the method. By means of the method and the device, multiple layers of T1 quantifying images can be collected in one time of breathholding, the whole heart can be covered in two or three times of breathholding, and thus time waste and patient discomfort caused by breathholding are reduced.

The invention provides an optimization-based measurement matrix imaging method. The method comprises the steps: 01) carrying out Fourier transform on a target image to obtain K-space data; 02) carrying out sampling on the K-space data through a sampling matrix to obtain sampled signals for transmission; 03) carrying out sparse transformation on the target image to enable a reconstructed signal to be K-sparse; 04) obtaining sparse coefficients through the sampled signals; and 05) carrying out processing on the sparse coefficients through a fast iteration threshold algorithm to obtain a reconstructed image, wherein the sampling matrix is obtained by carrying out superposition on a random radial sampling matrix and a similar circular ring sampling matrix, and is a variable-density radial similar circular ring matrix meeting non-coherence characteristics with the sparse matrix. The variable-density radial similar circular ring matrix in the method has high randomness and easily meets the non-coherence characteristics with the sparse matrix, so that an image recovery effect is good.

A system and method for evaluating subjects using MRI and a contrast agent that overcomes the low sensitivity nature of previous detection methods is provided by using a 3D golden-angle-based radial sampling approach. In one configuration, direct detection of metabolic H₂¹⁷O generated from mitochondrial respiration may be imaged. Radial encoding allows for the use of ultra-short echo-time to compensate for signal loss due to the short T₂ relaxation time of ¹⁷O and other contrast agents. In addition, the golden-ratio-based sampling scheme has the flexibility of enabling various undersampling schemes and retrospective selection of temporal resolution for dynamic imaging. A 3D radial sampling scheme may also give rise to additional SNR gain by further shortening the echo-time.

The invention relates to a method for generating a variable resolution digital elevation model. The method comprises the following steps of: establishing an east-north-sky right-handed coordinate system according to a measured topographic region, establishing a new plane coordinate system X'O'Y' in an XOY plane by using a measurement station point as a center, and establishing a polar coordinate system by using the original point of the new plane coordinate system as a pole and the direction far away from the center of the measurement station point as a polar axis; acquiring a three-dimensional data discrete point of the measured topographic region under the east-north-sky right-handed coordinate system; determining an angle sampling range in the polar coordinate system according to the measured topographic region, setting angle sampling intervals, and calculating the quantity of elevation sampling points required in the angle range; determining a radial sampling range along each angle direction, determining radial sampling change rates and sampling intervals, and calculating the quantity of the elevation sampling points required in the radial direction; and acquiring polar coordinates of all the elevation sampling points within the angle sampling range and the radial sampling range, constructing an irregular triangulation network according to the data discrete point, and calculating through interpolation to obtain elevation values of all the elevation sampling points. The method can be widely applied to data storage and expression during topographic and geomorphic measurement.

The invention provides a motion signal extracting method and device for self-gating three-dimensional cardiac imaging, and relates to the technical field of three-dimensional cardiac imaging. The method includes the steps that according to the TureFISP sequence, cardiac cine imaging data are obtained by adopting a multi-echo three-dimensional radial mixed collecting mode; signal values of multiple points are obtained from radial sampling lines of all collecting layers in the cardiac cine imaging data, and average values of the signal values of the multiple points are determined to serve as navigation signals; the navigation signals are subjected to inverse Fourier transformation to be transformed into an image domain, and heartbeat and breathing motion mixed signals are obtained through weighting; the heartbeat and breathing motion mixed signals are filtered through a band-pass filter to obtain heartbeat signals and breath signals; according to the heartbeat signals and the breath signals, the cardiac cine imaging data are arrayed and synchronized again to generate three-dimensional cardiac images. The problem that in the prior art, the quality of the rebuilt cardiac cine images is affected as obtained motion signals are inaccurate is solved.

The invention discloses a heart magnetic resonance imaging method based on a multi-scale low-rank model, and provides a new method for heart magnetic resonance imaging researching. A radial sampling track is adopted to realize undersampling of heart K space data, and full heart data radial undersampling is realized, and thereafter magnetic resonance data acquisition speed is accelerated, and then scanning time of a magnetic resonance device is reduced. The minimization expression of the heart magnetic resonance data based on multi-scale low-rank decomposition is used to improve the precision of the magnetic resonance imaging. A convex optimization problem of a reconstructed image is solved by an alternating direction multiplier method, and a speed of magnetic resonance imaging reconstruction is improved, and therefore the texture of the result of the reconstructed image is clear, and the edge is smooth.

The invention relates to the technical field of magnetic resonance imaging, and discloses a magnetic resonance dynamic imaging method, a device and a readable medium. The magnetic resonance dynamic imaging method comprises the following steps: step 1: filling the K space with a sampling mode of subsection acquisition between different respiratory cycles after receiving a trigger signal, and sampling data in the K space with a sampling mode of golden angle radial sampling trajectory in each cardiac cycle, wherein the golden angle radial sampling trajectory is approximated by an uniform radial sampling trajectory with the number of projections meeting a Fibonacci number; step 2: reconstructing an image on the two dimensions including the projection of radial sampling and the cardiac cycle with a-f BLAST method. The method of the present invention adopts the special uniform radial sampling trajectory (with the number of projections being a Fibonacci number) to approximate the golden angleradial sampling trajectory, breaking the limit of the uniform radial sampling of circular offset as the sampling mode, and can be applied in the golden angle radial sampling trajectory commonly usedin the dynamic imaging.

In a method, magnetic resonance apparatus, and pulse optimization computer for determining a pulse sequence for radial sampling of k-space in magnetic resonance imaging, the amplitudes and the increases with respect to time of readout gradients and phase gradients for individual sections of k-space are determined depending on an orientation of the respective section in k-space and depending on global maximum values of the amplitudes and the increases of the gradients on the physical axes.