Abstract: Systems and methods for image segmentation using a deformable atlas are provided. One method includes obtaining one or more target images, obtaining one or more propagated label probabilities for the one or more target images, and segmenting the one or more target images using a cost function of a deformable atlas model. The method further includes identifying segmented structures within the one or more target images based on the segmented one or more target images.

Abstract: A method of compressed sensing for multi-shell magnetic resonance imaging includes obtaining magnetic resonance imaging data, the data being sampled along multi-shell spherical coordinates, the spherical coordinates coincident with a plurality of spokes that converge at an origin, constructing a symmetric shell for each respective sampled multi-shell to create a combined set of data, performing a three-dimensional Fourier transform on the combined set of data to reconstruct an image, and de-noising the reconstructed image by iteratively applying a sparsifying transform on non-sampled data points of neighboring shells. The method can also include randomly under-sampling the imaging data to create missing data points. A system configured to implement the method and a non-transitory computer readable medium are also disclosed.

Abstract: A system and method of self-calibrated correction for residual phase in phase-contrast magnetic resonance (PCMR) imaging data. The method includes receiving PCMR image data from an MR scanner system, segmenting static tissue from non-static cardiovascular elements of the image data, calculating a non-linear fitted-phase basis function, the non-linear fitted-phase basis function based on system artifacts of the PCMR system, adding the non-linear fitted-phase basis function to linear fit terms, and subtracting the result of the adding step from the PCMR imaging data. The system includes a PCMR scanning apparatus configured to provide PCMR image data, a scanner control circuit configured to control the scanning apparatus during image acquisition, the scanner control circuitry in communication with a control processor, the control processor configured to execute computer-readable instructions that cause the control processor to perform the method. A non-transitory computer-readable medium is also disclosed.

Abstract: A method of compressed sensing for multi-shell magnetic resonance imaging includes obtaining magnetic resonance imaging data, the data being sampled along multi-shell spherical coordinates, the spherical coordinates coincident with a plurality of spokes that converge at an origin, constructing a symmetric shell for each respective sampled multi-shell to create a combined set of data, performing a three-dimensional Fourier transform on the combined set of data to reconstruct an image, and de-noising the reconstructed image by iteratively applying a sparsifying transform on non-sampled data points of neighboring shells. The method can also include randomly under-sampling the imaging data to create missing data points. A system configured to implement the method and a non-transitory computer readable medium are also disclosed.

Abstract: Magnetic resonance imaging systems and methods are provided. A method includes applying a slice selection gradient perpendicular to a desired slice plane and applying, substantially simultaneously with the slice selection gradient, a radiofrequency nuclear magnetic resonance excitation pulse having a bandwidth corresponding to the desired slice plane and a frequency corresponding to the frequency of protons present in the desired slice plane. The method also includes applying, during an encoding period and in a first direction, a phase encoding gradient having a phase encoding portion and a shearing portion and applying, during the readout period and in a second direction perpendicular to the first direction, a frequency encoding gradient having a portion having substantially the same shape as the shearing portion of the phase encoding gradient.

Abstract: Systems and methods for Magnetic Resonance Angiography (MRI) are provided. One method includes obtaining Magnetic Resonance (MR) velocity data and determining a distance map for one or more vessels to define a distance path. The method also includes calculating, using the MR velocity data, at a plurality of time intervals and for a plurality of pixels (i) a distance traveled during a current time interval as a current distance traveled, wherein a total distance traveled is incremented by the current distance traveled and (ii) a bolus signal using a bolus signal profile, the distance path and total distance traveled, wherein a current time interval is incremented by a defined time step.

Abstract: Systems and methods for image segmentation using a deformable atlas are provided. One method includes obtaining one or more target images, obtaining one or more propagated label probabilities for the one or more target images, and segmenting the one or more target images using a cost function of a deformable atlas model. The method further includes identifying segmented structures within the one or more target images based on the segmented one or more target images.

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: A method includes obtaining a plurality of magnetic resonance (MR) coil images of a subject of interest, each MR coil image being generated from one of an array of MR receiving coils; combining the plurality of coil images to generate an image estimate of the subject of interest; performing a multichannel blind deconvolution (MBD) process including: deriving coil sensitivity information for every one of the array of MR receiving coils based on the image estimate or a filtered image estimate derived from the image estimate; updating the image estimate or the filtered image estimate using the derived coil sensitivity information to generate an updated image estimate; and applying a homomorphic filter to the image estimate to derive the filtered image estimate, or to the updated image estimate to derive a filtered updated image estimate, or a combination thereof.

Abstract: The system and method of the invention combines target image intensity into a maximum likelihood estimate (MLE) framework as in STAPLE to take advantage of both intensity-based segmentation and statistical label fusion based on atlas consensus and performance level, abbreviated iSTAPLE. The MLE framework is then solved using a modified expectation-maximization algorithm to simultaneously estimate the intensity profiles of structures of interest as well as the true segmentation and atlas performance level. The iSTAPLE greatly extends the use of atlases such that the target image need not have the same image contrast and intensity range as the atlas images.

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 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: A method includes obtaining a plurality of magnetic resonance (MR) coil images of a subject of interest, each MR coil image being generated from one of an array of MR receiving coils; combining the plurality of coil images to generate an image estimate of the subject of interest; performing a multichannel blind deconvolution (MBD) process including: deriving coil sensitivity information for every one of the array of MR receiving coils based on the image estimate or a filtered image estimate derived from the image estimate; updating the image estimate or the filtered image estimate using the derived coil sensitivity information to generate an updated image estimate; and applying a homomorphic filter to the image estimate to derive the filtered image estimate, or to the updated image estimate to derive a filtered updated image estimate, or a combination thereof.

Abstract: Systems and methods for Magnetic Resonance Angiography (MRI) are provided. One method includes obtaining Magnetic Resonance (MR) velocity data and determining a distance map for one or more vessels to define a distance path. The method also includes calculating, using the MR velocity data, at a plurality of time intervals and for a plurality of pixels (i) a distance traveled during a current time interval as a current distance traveled, wherein a total distance traveled is incremented by the current distance traveled and (ii) a bolus signal using a bolus signal profile, the distance path and total distance traveled, wherein a current time interval is incremented by a defined time step.

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: An improved self-calibration method for accelerated magnetic resonance imaging (MRI) using inversion recovery pulse sequences allows calibration data for determining coil sensitivity profiles to be acquired by employing a calibration pulse sequence within the delay time of an inversion recovery pulse sequence. The calibration pulse sequence includes a constrained number of calibration pulses having small flip angles so that acceptable longitudinal magnetization recovery is provided.

Abstract: An improved self-calibration method for accelerated magnetic resonance imaging (MRI) using inversion recovery pulse sequences allows calibration data for determining coil sensitivity profiles to be acquired by employing a calibration pulse sequence within the delay time of an inversion recovery pulse sequence. The calibration pulse sequence includes a constrained number of calibration pulses having small flip angles so that acceptable longitudinal magnetization recovery is provided.