1Imaging Research, Sunnybrook Research Institute, Toronto, ON, Canada; 2Department of Radiology, University of Toronto, Toronto, ON, Canada; 3Department of Radiology, University of British Columbia, Vancouver, B.C., Canada; 4Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
It has been shown that the B0 inhomogeneity distortion occuring in single-coil EPI diffusion weighted images (DWIs) can be corrected using PLACE, a phase-based method. In this work, a method is presented which combines the multi-coil data for the two images required for PLACE while preserving the useful phase information. It is shown that although the inter-coil phase relation is not known, the phase relation between the two EPI acquisitions is coil independent for b=0. Phase difference images are produced for each coil and then complex averaging yields the distorted phase ramp. PLACE can use this to correct magnitude DWIs.