Optimizing Phase Correction for Multi-Shot DWI with Conjugate Gradient Method and Oversampling
Liu C, Moseley M, Bammer R
Little is known about optimizing multi-shot DWI for motion correction. With the newly introduced conjugate gradient (CG) phase correction method we can evaluate the phase correction capability of different readout strategies in the presence of k-space undersampling and phase map errors, and thus, empirically optimize the motion correction capability for multi-shot DWI. Through simulation and in vivo high-resolution DTI, we demonstrate that trajectories that oversample the center of k-space have more favorable properties for phase correction. CG phase correction combined with oversampling increases tolerance for trajectory and phase map imperfection, thus offers more robustness for motion correction of multi-shot DWI.