title: Understanding phase maps in MRI: a new cutline phase unwrapping method.
abstract: This paper describes phase maps. A review of the phase unwrapping problem is given. Different structures, in particular fringelines, cutlines, and poles, contained within a phase map are described and their origin and behavior investigated. The problem of phase unwrapping can then be addressed with a better understanding of the source of poles or inconsistencies. This understanding, along with some assumptions about what is being encoded in the phase of a magnetic resonance image, are used to derive a new method for phase unwrapping which relies only on the phase map. The method detects cutlines and distinguishes between noise-induced poles and signal undersampling poles based on the length of the fringelines. The method was shown to be robust to noise and successful in unwrapping challenging clinical cases.
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T IZI, Canada.
authors.forename: Sofia
authors.initials: S
authors.lastname: Chavez
authors.forename: Qing-San
authors.initials: QS
authors.lastname: Xiang
authors.forename: Li
authors.initials: L
authors.lastname: An
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity; D018780:Body Surface Potential Mapping / Q000379:methods; D003198:Computer Simulation; D003326:Coronary Circulation / Q000502:physiology; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D012815:Signal Processing, Computer-Assisted; D013269:Stochastic Processes