Standard Article

Phase Unwrapping

  1. Leslie Ying

Published Online: 14 APR 2006

DOI: 10.1002/9780471740360.ebs1356

Wiley Encyclopedia of Biomedical Engineering

Wiley Encyclopedia of Biomedical Engineering

How to Cite

Ying, L. 2006. Phase Unwrapping. Wiley Encyclopedia of Biomedical Engineering. .

Author Information

  1. University of Wisconsin-Milwaukee, Department of Electrical Engineering and Computer Science, Milwaukee, Wisconsin

Publication History

  1. Published Online: 14 APR 2006


Phase unwrapping is the reconstruction of the original true phase of a wave from its modulo 2π values. It originates in a variety of applications, such as synthetic aperture radar, magnetic resonance imaging, and adaptive optics. In this article, the problem of two-dimensional phase unwrapping is defined and the challenges are addressed. A variety of established approaches to the problems are reviewed and compared, and their advantages and disadvantages are discussed. Among the many phase unwrapping applications, the article focussed on magnetic resonance imaging and explains how phase unwrapping is used in field mapping, inversion recovery, and flow imaging.


  • phase unwrapping;
  • magnetic resonance imaging;
  • field inhomogeneity;
  • flow imaging