Chavez Sofia, Xiang Qing-San, An Li
Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T IZI, Canada.
IEEE Trans Med Imaging. 2002 Aug;21(8):966-77. doi: 10.1109/TMI.2002.803106.
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.
本文描述了相位图。对相位展开问题进行了综述。描述了相位图中包含的不同结构，特别是条纹线、切割线和极点，并研究了它们的起源和行为。然后，通过更好地理解极点或不一致性的来源，可以解决相位展开问题。这种理解，连同关于磁共振图像相位中编码内容的一些假设，被用于推导一种仅依赖于相位图的相位展开新方法。该方法检测切割线，并根据条纹线的长度区分噪声诱导的极点和信号欠采样极点。结果表明，该方法对噪声具有鲁棒性，并且在展开具有挑战性的临床病例时取得了成功。
