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A Fast, Automated, N-Dimensional Phase Unwrapping Algorithm

FMRIB Technical Report TR01MJ1

Mark Jenkinson

Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB),
Department of Clinical Neurology, University of Oxford, John Radcliffe Hospital,
Headley Way, Headington, Oxford, UK


This report investigates the general problem of phase unwrapping for arbitrary n-dimensional phase maps. A cost function-based approach is outlined which leads to an integer programming problem. To solve this problem a best-pair-first region merging approach is adopted as the optimisation method. The algorithm has been implemented and tested with 3D MRI medical data for fMRI applications in EPI unwarping and rapid, automated shimming.

Keywords: phase unwrapping; echo planar imaging (EPI); field mapping.

Mark Jenkinson 2001-10-12