基于幅度图像引导的磁敏感加权图像相位解缠算法

发布时间：2018-06-18 19:16

本文选题：磁敏感加权成像 + 幅度图像　；参考：《生物医学工程学杂志》2017年05期

【摘要】：为了更好地利用相位信息补偿血流造成的影响,本文对磁敏感加权成像(SWI)中存在的相位缠绕问题展开了研究。为提高解缠绕的准确性,本文提出了幅度图像引导的磁敏感加权图像相位解缠算法。基本思路如下:(1)通过改进旋转不变非局部主成分分析滤波(PRI-NL-PCA)降低噪声影响;(2)结合C-V模型水平集提取相位图像中对应的实性组织区域,从而规避背景噪声对相位解缠方法的影响;(3)采用相位补偿的方法约束K空间重建出的相位图像。最后,利用四种统计量作为量化指标,评价解缠绕方法的可靠性:相位误差的突变点个数、均值(M)、方差(Var),以及阳性百分比(Pos)和阴性百分比(Neg)。通过对比仿真数据和226组真实头部磁敏感数据,结果表明,本文算法相对于经典的枝切法和最小二乘法,解缠绕结果具有较高的准确性。
[Abstract]:In order to make better use of phase information to compensate for the effect of blood flow, the phase winding problem in magnetic sensitive weighted imaging (SWI) is studied in this paper. In order to improve the accuracy of unwinding, a phase unwrapping algorithm for magnetically sensitive weighted images guided by amplitude images is proposed. The basic idea is as follows: 1) reducing the noise by improving the rotation-invariant non-local principal component analysis filter (PRI-NL-PCAA) and combining the C-V model level set to extract the corresponding real tissue region in the phase image. In order to avoid the influence of background noise on phase unwrapping method, phase compensation method is used to constrain the reconstructed phase image in K space. Finally, the reliability of the unwinding method is evaluated by using four kinds of statistics as quantitative indexes: the number of abrupt points of phase error, the mean value, the variance and the positive percentage poss) and the negative percentage. By comparing the simulation data with 226 groups of real head magnetic sensitive data, the results show that the proposed algorithm is more accurate than the classical branch cutting method and the least square method.
【作者单位】：四川大学电气信息学院医学信息工程系;
【基金】：四川省科技厅支撑项目(No.2015KJT0002-2014SZ0124)
【分类号】：R445.2;TP391.41

【相似文献】