The University of Arizona

Maria Altbach

Ali Bilgin

Chuan Huang

Christian Graff

Mahesh Bharath Keerthivasan

Zhiyang Fu

Sagar Mandava

Diego R Martin

A method for producing a streak-suppressed magnetic resonance (MR) image of a subject includes generating an interference covariance matrix {circumflex over ( )}R front N coil images Ij (x,y), j={1, 2, . . . , N}, each of the N coil images Ij (x,y) corresponding to MR signals detected by a respective one of a phased array of N coils of an MRI scanner. The MR signals originate in voxels of the subject corresponding to an artifact-corrupted region of a coil image. Coordinates (x,y) correspond to a location within a cross-sectional plane of the subject. The method also includes, for subject-regions of cross-sectional plane centered at a respective location (x,y), determining a coil weight vector W (x,y) from {circumflex over ( )}R. The method also includes generating the streak-suppressed MR image as a weighted sum of the coil images Ij (x,y), each weight of the weighted sum being Wj* (x,y), a jelement of a complex conjugate of coil weight vector W (x,y).

MRI streak-artifact suppression, system and method

A method for producing a streak-suppressed MR image of a subject includes (i) generating an interference correlation matrix from M coil images, (ii) producing eigenvectors of the interference correlation matrix, and (iii) determining, from the subspace-eigenvectors, a projection matrix of the interference null space. The subspace-eigenvectors include a plurality of subspace-eigenvectors that span an interference subspace and a plurality of null-space-eigenvectors that span an interference null space. The method also includes generating, from N coil images derived from a respective one of N MR signals, N streak-suppressed multi-coil images by either (i) preprocessing the N coil images with the projection matrix and applying an image-reconstruction technique to each of the resultant N preprocessed coil images, or (ii) applying an image-reconstruction technique to each of the N coil images to obtain N reconstructed coil images and post-processing the resultant N reconstructed coil images with the projection matrix.

A system and method for processing highly undersampled multi-echo spin-echo data by linearizing the slice-resolved extended phase graph model generates highly accurate Tmaps with indirect echo compensation. Principal components are used to linearize the signal model to estimate the Tdecay curves which can be fitted to the slice-resolved model for T2 estimation. In another example of image processing for highly undersampled data, a joint bi-exponential fitting process can compensate for image variations within a voxel and thus provide partial voxel compensation to produce more accurate Tmaps.

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Tucson, AZ, United States of America

Maria Altbach