A Robust and Efficient Method to Unwrap MR Phase Images
L. Ying, J. X. Ji, D. C. Munson, Jr. , Z. P. Liang, R. Koetter, B. J. Frey University of Illinois at Urbana Champaign, Urbana, IL, United States, University of Toronto, Toronto, Ontario, Canada SYNOPSIS Phase unwrapping finds many important applications in MRI, ranging from field mapping to flow imaging. In this paper, we propose a novel approach to 2-D phase unwrapping, which models the true phase as a Gaussian Markov random field. The phase is unwrapped using the maximum a posteriori (MAP) rule. The underlying optimization problem is solved using a two-dimensional dynamic programming algorithm, which is efficient and robust to noise. The proposed algorithm has been tested using various MRI data (acquired using spin-echo and gradient-echo sequences), yielding excellent phase maps.