21 results about "Echo-planar imaging" patented technology

The present disclosure provides an example method for using an MRI system electrically coupled to a computing device. The method includes generating, via the MRI system, an echo-shifted echo-planar imaging with blip up / down acquisition (“esEPI-BUDA”) pulse sequence including a first radiofrequency (“RF”) pulse and a second RF pulse, the first RF pulse followed by a first echo-train that is interleaved with the first and the second RF pulses, and the second RF pulse followed by a second echo-train such that the first and the second echo-trains have opposite phase-encoding blip gradient polarities to traverse echo planar imaging (“EPI”) k-space in a reversed order. In response to the pulse sequence being generated, the MRI system acquires two k-space datasets within a single shot and corrects image distortion, via the MRI system, based on the two acquired k-space datasets.

An echo planar imaging method capable of reducing image distortion is provided. Two radio frequency (RF) pulses α and β are used to respectively flip over a longitudinal magnetization into a transverse plane at different moments, so as to obtain observable transverse magnetization; the transverse magnetization obtained by flipping over the longitudinal magnetization by means of α and β are respectively rephased in two different echo trains by means of gradient pulses. Navigator echo signals are respectively collected before the two gradient echo trains, and the amplitude difference between two gradient echo train signals is corrected on the basis of the amplitude difference between the two navigator echo signals. Correcting the signals collected by the two gradient echo trains, so as to obtain two pieces of image data, and the two pieces of image data are averaged to obtain a final image.

A method for performing magnetic resonance imaging of an examination region (ROI) by means of an echo plane sequence is described. In the method, a theoretical model is generated which depicts the vibration structure of the unit (1b) which generates the magnetic field, in which an eddy current is induced in the vibration structure by the vibration of the vibration structure, said eddy current generating a gradient disturbing magnetic field in the examination region (ROI). A gradient disturbing magnetic field is determined based on a theoretical model (MMF). In addition, an echo plane sequence is applied. A magnetic resonance signal (RX) is then received from the examination region (ROI), and magnetic resonance raw data (RD) is generated on the basis of the magnetic resonance signal. The corrected magnetic resonance raw data (KRD) is determined on the basis of the magnetic resonance raw data (RD) and on the basis of the determined gradient interference magnetic field in the examination region (ROI). Finally, magnetic resonance image data (BD) is reconstructed on the basis of the corrected magnetic resonance raw data (KRD). A magnetic resonance imaging system (1) is also described.

Disclosed in the present invention are a 3D navigator-based 3D gradient spin-echo diffusion imaging method, and a device. The method comprises: first, using a global saturation module to destroy previous residual transverse magnetization; second, by means of a diffusion encoding module, embedding a pair of trapezoidal cosine oscillation gradients or pulse gradients into radio frequency pulses of 90°x-180°y-90°-x, and separating diffusion encoding from signal acquisition; then using a fat saturation module to suppress a fat signal; using a 3D gradient spin-echo readout method to acquire an image signal; and finally, acquiring a 3D navigation echo signal in the last spin echo for correcting a phase error between multiple excitations. The present invention can effectively eliminate phase errors between multiple acquisitions and realize high-resolution whole-brain diffusion imaging. Compared with 2D echo planar imaging, the present invention increases the signal-to-noise ratio of diffusion magnetic resonance imaging, thereby supporting higher-resolution whole-brain 3D diffusion magnetic resonance imaging.

For distortion correction in magnetic resonance (MR) echo planar imaging (EPI), a combination of supervised and unsupervised training provides deep learning with generalized applicability across different use cases as well as sufficient training data (e.g., less ground truth data is needed due to the inclusion of unsupervised learning). The neural network for displacement estimation may include deformable convolution and / or layers for a non-diffeomorphic displacement field. The network architecture features and / or combined supervised and unsupervised learning may be used together or individually.

A method for performing magnetic resonance imaging (MRI) with an echo-planar sequence of a region of interest (ROI) is described. In this method, a theoretical model representing an oscillating structure of a magnetic field-generating unit (1b) is generated. Oscillation of this structure induces eddy currents, which in turn generate a gradient-like interference magnetic field in the ROI. This gradient-like interference magnetic field is determined based on the theoretical model (MMF). The echo-planar sequence is then played back. Magnetic resonance signals (RX) from the ROI are received, and raw magnetic resonance data (RD) is generated from these signals.Based on the raw magnetic resonance data (RD) and the determined gradient-like interference magnetic field in the area of ​​investigation (ROI), corrected raw magnetic resonance data (KRD) are generated. Finally, magnetic resonance image data (BD) are reconstructed based on the corrected raw magnetic resonance data (RD). A magnetic resonance imaging system (1) is also described.

The invention relates to the technical field of image processing, in particular to a method for evaluating the renal function of a nephrotic patient through diffusion tensor imaging. The method comprises the following steps: acquiring a kidney diffusion tensor original image through single excitation echo plane imaging; adjacent comparison is carried out on each pixel point, and a signal intensity difference and a gradient direction difference are extracted; judging local geometric distortion according to the difference information, and carrying out correction processing pixel by pixel to obtain a corrected high-quality diffusion tensor image; and finally, calculating a fitting tensor, extracting diffusion parameters of the renal cortex and the renal medullary region, quantitatively comparing the diffusion parameters with preset renal function indexes, and outputting an objective quantitative result of the renal function of the patient. According to the method, through pixel-by-pixel distortion correction and direction feature extraction, the precision of the diffusion tensor image and the accuracy of kidney region division are improved, and objective quantitative analysis of kidney functions is realized.

The invention relates to a plane echo imaging method and system, computer equipment and a storage medium, and the method comprises the steps: obtaining a K-space data set obtained after the radio frequency excitation of a to-be-imaged region, the K-space data set comprising an echo time dimension, the K space data set is under-sampled along at least one phase coding direction and echo time dimension; recovering the K space data set along at least one phase coding direction and echo time dimension to obtain an updated K space data set; and reconstructing according to the updated K space data set to obtain a plurality of plane echo images. According to the method and the device, the problem that plane echo imaging cannot give consideration to improvement of the signal-to-noise ratio, the robustness and the calculation speed of the image in related technologies is solved, and the signal-to-noise ratio, the robustness and the calculation speed of the plane echo imaging are comprehensively improved.

Techniques are provided for performing echo planar imaging (EPI) data correction. This includes obtaining positive and negative readout gradient calibration data of an imaging target through non-accelerated EPI acquisitions; respectively adopting first and second DPG kernels to be fitted and respectively used to eliminate phase errors of positive and negative readout gradients to fit the positive and negative readout gradient calibration data of the imaging target, with the fitting targets being positive and negative readout gradient data, respectively, in ghost-free target ACS data, and obtaining, after the fitting, a first and a second DPG kernel for final use; obtaining imaging data of the imaging target through an EPI acquisition; adopting the first and second DPG kernels to correct the phase errors of the imaging data to obtain phase-error-free imaging data.

A control system and method for a magnetic resonance imaging (MRI) system controller is provided to sub-sample k-space for an MRI scan. The method includes, for each radio-frequency excitation pulse in the MRI scan, sub-sampling ky-kz planes using a three-dimensional (3D) echo planar imaging (EPI) sequence by coherently sub-sampling phase encodings in the ky dimension and incoherently sub-sampling phase encodings in the kz dimension. The coherent sub-sampling corresponds to a number of radio-frequency excitation pulses. The ky-kz planes represent a sub-sampling pattern in the ky-kz space, using an incoherent sub-sampling in the kz dimension.

A method for performing magnetic resonance imaging of an examination region using an echo-planar sequence, including: generating a theoretical model which represents an oscillating structure of a magnetic field generation unit, wherein as a result of an oscillation of the oscillating structure, eddy currents are induced in the oscillating structure and produce a gradient-type interference magnetic field in the examination region; determining the gradient-type interference magnetic field based on the theoretical model; applying the echo-planar sequence; receiving magnetic resonance signals from the examination region, wherein magnetic resonance raw data is generated based on the magnetic resonance signals; determining corrected magnetic resonance raw data based on the magnetic resonance raw data and based on the determined gradient-type interference magnetic field in the examination region; and reconstructing magnetic resonance image data based on the corrected magnetic resonance raw data.

Exemplary systems, methods, and computer-accessible medium are provided that can generating functional magnetic resonance imaging data (MRI) for an entire brain in a fraction of the time of traditional MRI. Thus, exemplary systems, methods, and computer-accessible medium can be provided that can obtain a single average of an echoplanar image (EPI) sequence to generate functional MRI data, and acquire or generate a fully-formed image of the entire brain based on the functional MRI data using the single average of EPI sequence. This fully formed brain image can be obtained in, e.g., approximately 1-2 seconds (of course other timing of acquisition is possible). Further, the single average of the EPI sequence can acquire a fully formed brain image by acquiring all of k-space with Cartesian sampling.

The present invention discloses a method and device for correcting geometric distortion of MRI images, which relates to the field of medical image processing, and includes the steps of: acquiring echo planar imaging diffusion weighted imaging and fast spin echo diffusion weighted imaging from a magnetic resonance imaging device; performing preprocessing on the echo planar imaging diffusion weighted imaging and the fast spin echo diffusion weighted imaging to obtain preprocessed images. Main technical solutions and effects: Since geometric distortion will directly affect the accurate presentation of anatomical structures and lesion areas in MRI images, the present invention can provide more real and accurate image data by effectively correcting the geometric distortion in the echo planar imaging diffusion weighted imaging images, thereby improving the diagnostic accuracy of doctors, helping doctors better judge the location, size and shape of lesions, and further formulating more reasonable treatment plans.

The application relates to the technical field of nuclear magnetic resonance image reconstruction, and provides a multi-echo image reconstruction method, device and nuclear magnetic resonance imaging equipment, and the reconstruction method has high stability.In the application, based on a multi-shot echo planar imaging sequence, first multi-echo data corresponding to echo signals in a preset space are obtained; a basis part for constructing a reconstruction function is obtained according to the difference between second multi-echo data corresponding to the multi-echo image to be reconstructed in the preset space and the first multi-echo data; the basis part is added with a first constraint and a second constraint to obtain the reconstruction function; the first constraint is a constraint on a low-rank term in the multi-echo image to be reconstructed; the second constraint is a constraint on a residual term in the multi-echo image to be reconstructed; and the multi-echo image is reconstructed according to the low-rank term and the residual term for minimizing the reconstruction function.

The invention discloses a method of magnetic resonance imaging of an object (10), comprising: acquiring gradient echo signals from the object (10) using a multi-shot or multi-acquisition echo planar imaging, EPI, sequence, wherein each shot (21-24) or acquisition corresponds to a different k-space segment, wherein the different k-space segments only partially overlap in a central portion of k-space; deriving geometry distortion information by combining the echo signals of different shots (21-24) or acquisitions; and reconstructing a magnetic resonance, MR, image by combining the echo signals of the multiple shots (21-24) or acquisitions, correcting for motion between the different shots (21-24) or acquisitions based on the overlap of the different k-space segments, and using the geometry distortion information to reduce geometric distortions in the reconstructed MR image. An imaging system is further disclosed, comprising a computational system configured to perform the method.

A method for driving a MRI system to generate MRI data of an examination subject may include performing an accelerated echoplanar imaging with an undersampling according to a pulse sequence diagram to acquire k-space data. The pulse sequence diagram may have a plurality of repetitions respectively including: a first sampling diagram configured for an acquisition of k-space data for Nyquist ghost correction, or to generate magnetic field maps, a subsequent second sampling diagram configured for an accelerated echoplanar acquisition, and an excitation diagram that is common to both acquisitions. The first sampling diagram of a real subset of the plurality of repetitions may be modified to: supplement the acquired k-space data using a supplementation of k-space data missing due the undersampling, and / or correct image space of artifacts occurring due to the undersampling based on the k-space data acquired with the modified first sampling diagram.

The application relates to the technical field of image processing, in particular to a method for evaluating renal function of a nephropathy patient through diffusion tensor imaging. The method comprises the following steps: obtaining a kidney diffusion tensor original image through single-excitation echo planar imaging acquisition; then comparing adjacent pixels, extracting signal intensity difference and gradient direction difference; then judging local geometric distortion according to the difference information, and carrying out correction processing pixel by pixel to obtain a corrected high-quality diffusion tensor image; finally, calculating a fitting tensor, extracting diffusion parameters of a renal cortex and a renal medulla region, and comparing and quantifying the diffusion parameters with preset renal function indexes to output an objective quantitative result of renal function of the patient. Through the pixel-by-pixel distortion correction and direction feature extraction, the precision of the diffusion tensor image and the accuracy of the kidney region division are improved, and objective quantitative analysis of the renal function is realized.

Systems and methods are described for investigating brain-wide CSF flow dynamics and understanding the role of neural activity, including an Echo-Planar Time-resolved Imaging (EPT)I CSF flowmetry technique that can simultaneously acquire i) phase-contrast 4D CSF flow, ii) T2*-BOLD fMRI, and iii) T2- and S0-contrast changes. EPTI eliminates the distortion and blurring artifacts in Echo-Planar Imaging (EPI), as well as resolving multi-echo images within the readout, allowing for the separation of various contrasts including T2*, T2, and flow-encoded S0. This separation is particularly useful for obtaining clean BOLD-fMRI signals.

A method for performing magnetic resonance imaging (MRI) with an echo-planar sequence of a region of interest (ROI) is described. In this method, a theoretical model representing an oscillating structure of a magnetic field-generating unit (1b) is generated. Oscillation of this structure induces eddy currents, which in turn generate a gradient-like interference magnetic field in the ROI. This gradient-like interference magnetic field is determined based on the theoretical model (MMF). The echo-planar sequence is then played back. Magnetic resonance signals (RX) from the ROI are received, and raw magnetic resonance data (RD) is generated from these signals.Based on the raw magnetic resonance data (RD) and the determined gradient-like interference magnetic field in the area of ​​investigation (ROI), corrected raw magnetic resonance data (KRD) are generated. Finally, magnetic resonance image data (BD) are reconstructed based on the corrected raw magnetic resonance data (RD). A magnetic resonance imaging system (1) is also described.

A method for correcting echo planar imaging artifacts includes correcting at least one echo planar imaging artifact in an image to obtain a correct image. A trained neural network is used to correct the at least one echo planar imaging artifact. The image is obtained through echo planar imaging.