Higher dimensional homodyne filtering for suppression of incidental phase artifacts in multichannel MRI

The aim of this paper is to introduce procedural steps for extension of the 1Dhomodyne phase correction for k-space truncation in all gradient encodingdirections. Compared to the existing method applied to 2D partial k-space,signal losses introduced by the phase correction filter is observed to beminimal for the extended approach. In addition, the modified form of phasecorrection mitigates Incidental Phase Artifacts (IPA) due to truncation. Forparallel imaging with undersampling along phase encode direction, theextended homodyne filtering is shown to be effective for minimizing theseartifacts when each of the channel k-spaces are truncated along both phase andfrequency encode directions. This is illustrated with 2D partial k-space forflow compensated multichannel Susceptibility Weighted Imaging (SWI).Extension of our method to 3D partial k-space shows improved reconstructionof flow information in phase contrast angiography.