摘要
磁共振相位像的信息可应用于一些特殊MR成像技术,如磁敏感成像、弹性成像、温度监控等,但是扫描得到的相位像常常会出现相位缠绕导致相位信息不准确,因此相位解缠成为上述成像技术成功的关键。本文分析了目前常用Goldstein枝切算法产生错误解缠的原因,并在此基础上进行了算法改进,提出在解缠流程中引入掩模处理、滤波及最近邻偶极子对去除的最小生成树等步骤,从而改善Goldstein枝切算法需要的残差图。实验结果表明这种方法使得残差点数量明显下降,枝切线的重复连接、闭合回路及贯通线等引起错误解缠的情形得到改善,明显提高了解缠后的相位像质量。
The phase information of magnetic resonance （MR） phase image can be used in many MR imaging techniques, but phase wrapping of the images often results in inaccurate phase information and phase unwrapping is essential for MR imaging techniques. In this paper we analyze the causes of errors in phase unwrapping with the commonly used Goldstein Brunch-cut algorithm and propose an improved algorithm. During the unwrapping process, masking, filtering, dipole- remover preprocessor, and the Prim algorithm of the minimum spanning tree were introduced to optimize the residues essential for the Goldstein Brunch-cut algorithm. Experimental results showed that the residues, branch-cuts and continuous unwrapped phase surface were efficiently reduced and the quality of MR phase images was obviously improved with the proposed method.
出处
《南方医科大学学报》
CAS
CSCD
北大核心
2013年第2期239-242,共4页
Journal of Southern Medical University
基金
国家自然科学基金(61072033)
广州市行业工程中心建设项目(穗科信条[2010]13-1)~~
