摘要:
A method for measuring diffusional anisotropy in diffusion-weighted magnetic resonance imaging. The method includes determining an orientation diffusion function (ODF) for one or more fibers within a single voxel, wherein the ODF includes lobes representative of a probability of diffusion in a given direction for the one or more fibers. The method also includes characterizing an aspect ratio of the lobes. The method further includes determining a multi-directional anisotropy metric for the one or more fibers based on the aspect ratio of the lobes.
摘要:
A method for measuring diffusional anisotropy in diffusion-weighted magnetic resonance imaging. The method includes determining an orientation diffusion function (ODF) for one or more fibers within a single voxel, wherein the ODF includes lobes representative of a probability of diffusion in a given direction for the one or more fibers. The method also includes characterizing an aspect ratio of the lobes. The method further includes determining a multi-directional anisotropy metric for the one or more fibers based on the aspect ratio of the lobes.
摘要:
A method of generating a magnetic resonance (MR) image of a tissue includes acquiring MR signals at undersampled q-space encoding locations for a plurality of q-space locations that is less than an entirety of the q-space locations sampled at the Nyquist rate, wherein the acquired signal at the q-space locations represents the three-dimensional displacement distribution of the spins in the imaging voxel, synthesizing the MR signal for the entirety of q-space encodings using a compressed sensing technique for a portion of q-space locations at which MR data was not acquired, combining the acquired MR signals at q-space encodings and the synthesized MR signals at q-space encodings to generate a set of MR signals at q-space encodings that are evenly distributed in q-space, using the set of MR signals at q-space encodings to generate a function that represents a displacement probability distribution function of the set of spins in the imaging voxel, and generating an image of the tissue based on at least a portion of the generated function. A system and computer readable medium are also described herein.
摘要:
A signal processing method include steps initializing a residual data signal representative of an acquired data signal, determining a significant coefficient corresponding to the residual data signal, updating the residual data signal using the significant coefficient to generate updated residual data signal, iteratively determining significant coefficients to generate a plurality of significant coefficients using the updated residual data signal, updating the plurality of significant coefficients by using a successive approximation technique, to improve the numerical accuracy of the significant coefficients and reconstructing a data signal using the updated plurality of significant coefficients.
摘要:
A method for reconstructing an image in a magnetic resonance imaging system is provided. The method includes steps of acquiring magnetic resonance signals from a plurality of receiver coils placed about a subject, each receiver coil having a coil sensitivity, iteratively polling each acquired magnetic resonance signal for determining one or more significant wavelet components of each acquired magnetic resonance signal by utilizing a coil sensitivity function of each receiver coil for each acquired magnetic resonance signal, iteratively determining one or more coefficients based on the one or more significant wavelet components to generate a plurality of coefficients for each acquired magnetic resonance signal, reconstructing an image utilizing a corresponding plurality of coefficients corresponding to each acquired magnetic resonance signal, and generating a composite image by combining the reconstructed images.
摘要:
An image reconstruction technique determines linear combinations of receiver channel information that contribute the most to image SNR and quantifies the SNR loss for the reduced receiver channel set for image reconstruction to reduce the computational burden placed on the reconstruction engine of an MRI system.
摘要:
A signal processing method is provided. The signal processing method includes the steps of generating undersampled data corresponding to an object, determining a variable thresholding parameter based on a composition of the undersampled data, and iteratively determining thresholded coefficients to generate a plurality of coefficients by utilizing the undersampled data, a current solution and the variable thresholding parameter by updating the variable thresholding parameter and the current solution, and reconstructing a data signal using the plurality of coefficients.
摘要:
A signal processing method include steps initializing a residual data signal representative of an acquired data signal, determining a significant coefficient corresponding to the residual data signal, updating the residual data signal using the significant coefficient to generate updated residual data signal, iteratively determining significant coefficients to generate a plurality of significant coefficients using the updated residual data signal, updating the plurality of significant coefficients by using a successive approximation technique, to improve the numerical accuracy of the significant coefficients and reconstructing a data signal using the updated plurality of significant coefficients.
摘要:
A method of generating a magnetic resonance (MR) image of a tissue includes acquiring MR signals at undersampled q-space encoding locations for a plurality of q-space locations that is less than an entirety of the q-space locations sampled at the Nyquist rate, wherein the acquired signal at the q-space locations represents the three-dimensional displacement distribution of the spins in the imaging voxel, synthesizing the MR signal for the entirety of q-space encodings using a compressed sensing technique for a portion of q-space locations at which MR data was not acquired, combining the acquired MR signals at q-space encodings and the synthesized MR signals at q-space encodings to generate a set of MR signals at q-space encodings that are evenly distributed in q-space, using the set of MR signals at q-space encodings to generate a function that represents a displacement probability distribution function of the set of spins in the imaging voxel, and generating an image of the tissue based on at least a portion of the generated function. A system and computer readable medium are also described herein.
摘要:
A system and method for accelerated MR imaging includes a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly comprising at least one RF transmit coil and comprising multiple coils to acquire MR images. The MRI apparatus also has a computer programmed to excite multiple pencil regions by use of an under-sampled echo-planar excitation trajectory and acquire MR signals simultaneously on multiple channels of the RF coil assembly. The computer is also programmed to separate contributions from the various multiple pencil regions by use of parallel imaging reconstruction.