Unwrapping highly wrapped phase using Nonlinear Multi Echo phase unwrapping

The unwrapping problem has been a major topic of research for over a decade. A variety of algorithms were suggested, but a correct solution is by no means guaranteed. In addition, many of these techniques are timeconsuming issues. In this work, we propose a simple and fast method, which combines conventional temporal unwrapping with a nonlinear phase model to unwrap highly wrapped Multi Echo data (Nonlinear Multi-Echo unwrapping). The approach was tested on simulated data and high-resolution in vivo brain data acquired from ten subjects at 3 Tesla demonstrating tbe promise of the proposed technique. Keywords— Phase unwrapping, GRE, Temporal unwrap.