Abstract: A magnetic resonance (MR) imaging method includes acquiring MR signals having phase and magnitude at q-space locations using a diffusion sensitizing pulse sequence performed on a tissue of interest, wherein the acquired signals each include a set of complex Fourier encodings representing a three-dimensional displacement distribution of the spins in a q-space location. The signals each include information relating to coherent motion and incoherent motion in the q-space location. The method also includes determining a contribution by coherent motion to the phase of the acquired MR signals; removing the phase contribution attributable to coherent motion from the acquired MR signals to produce a complex data set for each q-space location and an image of velocity components for each q-space location; and producing a three-dimensional velocity image from the image of the velocity components.

Abstract: Systems and methods for correcting magnetic resonance (MR) data are provided. One method includes receiving the MR data and correcting errors present in the MR data due to non-uniformities in magnetic field gradients used to generate the diffusion weighted MR signals. The method also includes correcting errors present in the MR data due to concomitant gradient fields present in the magnetic field gradients by using one or more gradient terms. At least one of the gradient terms is corrected based on the correction of errors present in the MR data due to the non-uniformities in the magnetic field gradients.

Abstract: The present disclosure relates to a receive coil assembly for use in magnetic resonance imaging of breast tissue. In certain embodiments the assembly comprises separable parts: a configurable mechanical support and a flexible receive coil array. The adjustability and separability of the receive coil array relative to the mechanical support allows the receive coil array to substantially conform to the breasts of the patient during imaging.

Abstract: Methods and systems using magnetic resonance and ultrasound for tracking anatomical targets for radiation therapy guidance are provided. One system includes a patient transport configured to move a patient between and into a magnetic resonance (MR) system and a radiation therapy (RT) system and an ultrasound transducer coupled to the patient transport, wherein the ultrasound transducer is configured to acquire four-dimensional (4D) ultrasound images concurrently with one of an MR acquisition or an RT radiation therapy session. The system also includes a controller having a processor configured to use the 4D ultrasound images and MR images from the MR system to control at least one of a photon beam spatial distribution or intensity modulation generated by the RT system.

Abstract: A magnetic resonance (MR) imaging method includes acquiring MR signals having phase and magnitude at q-space locations using a diffusion sensitizing pulse sequence performed on a tissue of interest, wherein the acquired signals each include a set of complex Fourier encodings representing a three-dimensional displacement distribution of the spins in a q-space location. The signals each include information relating to coherent motion and incoherent motion in the q-space location. The method also includes determining a contribution by coherent motion to the phase of the acquired MR signals; removing the phase contribution attributable to coherent motion from the acquired MR signals to produce a complex data set for each q-space location and an image of velocity components for each q-space location; and producing a three-dimensional velocity image from the image of the velocity components.

Abstract: 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.

Abstract: Systems and methods for generating a magnetic resonance (MR) image of a tissue are provided. A method includes acquiring MR raw data. The MR raw data corresponds to MR signals obtained at undersampled q-space locations for a plurality of q-space locations that is less than an entirety of the q-space locations and the MR signals at the q-space locations represent the three dimensional displacement distribution of the spins in the imaging voxel. The method also includes performing a joint image reconstruction technique on the MR raw data to exploit structural correlations in the MR signals to obtain a series of accelerated MR images and performing, for each image pixel in each accelerated MR image of the series of accelerated MR images, a compressed sensing reconstruction technique to exploit q-space signal sparsity to identify a plurality of diffusion maps.

Abstract: Magnetic material imaging (MMI) system including first and second sets of field-generating coils. Each of the field-generating coils of the first and second sets has an elongated segment that extends along an imaging axis of the medical imaging system. The imaging axis extends through a region-of-interest (ROI) of an object. The elongated segments of the first set of field-generating coils are positioned opposite the elongated segments of the second set of field-generating coils and the ROI is located between the first and second sets of field-generating coils. The MMI system also includes a coil-control module configured to control a flow of current through the first and second sets of field-generating coils to generate a selection field and to generate a drive field. The selection and drive fields combine to form a movable 1D field free region (FFR) that extends through the ROI.

Abstract: 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.

Abstract: A signal processing method is presented. The method includes acquiring undersampled data corresponding to an object, initializing a first image solution and a second image solution, determining a linear combination solution based upon the first image solution and the second image solution, generating a plurality of selected coefficients by iteratively updating the first image solution, the second image solution and the linear combination solution and adaptively thresholding one or more transform coefficients utilizing the undersampled data, an updated first image solution, an updated second image solution and an updated linear combination solution, and reconstructing a data signal using the plurality of selected coefficients.

Abstract: 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

Abstract: 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.

Abstract: A signal processing method is presented. The method includes acquiring undersampled data corresponding to an object, initializing a first image solution and a second image solution, determining a linear combination solution based upon the first image solution and the second image solution, generating a plurality of selected coefficients by iteratively updating the first image solution, the second image solution and the linear combination solution and adaptively thresholding one or more transform coefficients utilizing the undersampled data, an updated first image solution, an updated second image solution and an updated linear combination solution, and reconstructing a data signal using the plurality of selected coefficients.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In the method, system conditions may be monitored for at least a first time period within a periodic time interval, and network parameters for optimizing a wireless network may be determined. The determined network parameters may be implemented during a first time period within the at least one subsequent periodic time interval.