Patent classifications
G01R33/5618
Propeller with Dixon water fat separation
The invention relates to a magnetic resonance imaging system (100) for acquiring at least one set of k-space blade data from an imaging zone of a subject (118), wherein the magnetic resonance imaging system (100) comprises a memory (138) for storing machine executable instructions and a processor (130) for controlling the magnetic resonance imaging system (100), wherein execution of the machine executable instructions causes the processor (130) to perform for each blade of the at least one set of k-space blade data: control the MRI system (100) to acquire at least one k-space blade data using at least one echo time for purposes of performing a Dixon technique, wherein k-space blade data are acquired in accordance with a blade shape; reconstruct at least one blade image data using the at least one k-space blade data; generate water blade image data and fat blade image data using the at least one blade image data; and transform the water and fat blade image data to water and fat k-space blade data respectively and perform PROPELLER reconstruction of the water and fat k-space blade data.
IMAGING SYSTEMS AND METHODS
An imaging method may include obtaining imaging data associated with a region of interest (ROI) of an object. The imaging data may correspond to a plurality of time-series images of the ROI. The imaging method may also include determining, based on the imaging data, a data set including a spatial basis and one or more temporal bases. The spatial basis may include spatial information of the imaging data. The one or more temporal bases may include temporal information of the imaging data. The imaging method may also include storing, in a storage medium, the spatial basis and the one or more temporal bases.
Magnetic resonance imaging system and positioning method of implant therefor
Provided in the present application are a magnetic resonance imaging system, a positioning method of an implant therefor, and a non-transitory computer-readable storage medium. The positioning method of the implant for the magnetic resonance imaging system includes: executing a first scanning sequence to obtain original image data and reconstructing an edge image of the implant on the basis of the original image data. The first scanning sequence includes: a radio frequency excitation pulse and a first layer selection gradient pulse corresponding to the radio frequency excitation pulse, the frequency of the radio frequency excitation pulse having a preset offset relative to a center frequency; and a radio frequency refocusing pulse and a second layer selection gradient pulse corresponding to the radio frequency refocusing pulse, the direction of the second layer selection gradient pulse being opposite to the direction of the first layer selection gradient pulse.
METHODS AND SYSTEMS FOR MAGNETIC RESONANCE IMAGING
The present disclosure relates to a system and method for MRI with respect to vessels and bleedings. The method may include exciting a region of interest by applying an RF pulse, wherein the region of interest includes a vessel region and a bleeding region. The method may further include acquiring a plurality of echo signals related to the region of interest. The method may further include generating one or more magnitude images based on the plurality of echo signals, generating a first image with respect to the vessel region based on the one or more magnitude images, generating one or more phase images based on the plurality of echo signals, and generating a second image with respect to a distribution of susceptibility of the bleeding region based on the one or more phase images.
Multi-echo PRESTO
A magnetic resonance imaging system (78) includes a magnetic resonance imaging device (80), one or more processors (104), and a display (106). The magnetic resonance imaging device (80) includes a magnet (82), gradient coils (88), and one or more radio frequency coils (92). The magnet (82) generates a Bo field. The gradient coils (88) apply gradient fields to the Bo field. The one or more radio frequency coils (92) generate a radio frequency pulse to excite magnetic resonance and measure generated gradient echoes. The one or more processors (104) are configured to activate (116) the one or more radio frequency coils (92) to generate a series of radio frequency pulses spaced by repetition times and to induce magnetic resonance. The one or more processors (104) are configured to control (118) the gradient coils to apply after each RF pulse readout gradient field pulses which refocus the resonance into a plurality of gradient echoes, shift and refocus gradient field pulses which shift and refocus at least one of the echoes to a subsequent repetition time, and receive and demodulate the gradient echoes to form k-space data lines. The one or more processors are configured to reconstruct (124) one or more images from the measured one or more gradient echoes. A display (106) displays the one or more reconstructed images.
Magnetic resonance T2 preparatory pulses for magnetic field inhomogeneity robustness and contrast optimization
Methods and systems to obtain and apply T.sub.2 preparatory radiofrequency (RF) pulse sequences for magnetic resonance imaging (MRI) are provided. The iterative methods may employ propagation of the magnetization state of the object being imaged and a comparison with a target magnetization state. The methods disclosed may be used to obtain MRI pulse sequences that may optimize T.sub.2 relaxation contrast. The produced RF pulse sequences may be robust to effects from inhomogeneity of the magnetic fields or other environmental or physiological perturbations.
MR imaging apparatus and method for generating a perfusion image with motion correction
A magnetic resonance method and system are provided for generating real-time motion-corrected perfusion images based on pulsed arterial spin labeling (PASL) with a readout sequence such as a 3D gradient and spin echo (GRASE) image data acquisition block. The real-time motion correction is achieved by using a volumetric 3D EPI navigator that is provided during an intrinsic delay in the PASL sequence, which corrects for motion prospectively and does not extend the image data acquisition time as compared to a similar non-motion-corrected imaging procedure.
Method and apparatus for generating a magnetic resonance image using combined excitation by a whole body coil and a local coil
In a method and magnetic resonance (MR) apparatus for producing an MR image of an examination object with an MR imaging sequence, at least one RF pulse is radiated by a whole body coil of the MR scanner of the MR apparatus during the imaging sequence, at least one RF pulse is radiated by a local transmit coil of the MR scanner during the imaging sequence, MR signals that are generated by the combined radiated RF pulses are read out, and an MR image is reconstructed from the read-out MR signals.
METHODS AND APPARATUS FOR BONE SEGMENTATION IN MAGNETIC RESONANCE IMAGES
Methods and apparatus for processing magnetic resonance imaging (MRI) data to perform bone segmentation. MRI data comprising a set of gradient-echo images acquired throughout a spin echo is processed to generate a bone segmentation image. The bone segmentation image is generated based, at least in part, on at least two images in the set of gradient-echo images, wherein the at least two images include a first image corresponding to a beginning portion of the spin echo and a second image corresponding to a central portion of the spin echo.
FAT CHARACTERIZATION METHOD USING MRI IMAGES ACQUIRED WITH A MULTIPLE-GRADIENT ECHO SEQUENCE
A method for post-processing images of a region of interest in a subject, the images being acquired with a magnetic resonance imaging technique, the method for post-processing comprising at least the step of: unwrapping the phase of each image, extracting a real signal over echo time for at least one pixel of the unwrapped images, and calculating fat characterization parameters by using a fitting technique applied on a model, the model being a function which associates to a plurality of parameters each extracted real signal, the plurality of parameters comprising at least two fat characterization parameters and at least one parameter obtained by a measurement, the fitting technique being a non-linear least-square fitting technique using pseudo-random initial conditions.