作　　者： ; ; ; ;

机构地区： 华南理工大学理学院

出　　处： 《计算机仿真》 2011年第8期246-249,共4页

摘　　要： 研究医学成像,准确估计弹性病理精度,在时域互相关的超声弹性成像中,组织位移时会产生"蠕虫"噪声,使位移估计存在误差。针对保证成像的精度问题,为了有效消除组织位移中的"蠕虫"噪声,并准确估计组织应变,提出了利用小波变换对组织位移进行贝叶斯阈值去噪的方法,并与传统的FIR低通滤波、IIR低通滤波、均值滤波进行了对比。仿真结果表明,改进的算法能有效降低组织位移估计中的噪声,并获得了较好的组织应变图视觉效果和位移信噪比。 In elastography algorithm based on time domain correlation method,large overlap can improve the spatial resolution,but it can generate ＂worm＂ artifact in estimated displacement result.Meanwhile,errors in the displacement estimation will be introduced because of decorrelation of the RF echo signals,and the tissue strain is obtained from numerical differentiation of the tissue displacement.This operation can enlarge noise,and increase the error of strain results.To eliminate the ＂worm＂ artifact efficiently,and estimate strain accurately,this paper proposes a Bayes threshold denoising method based on wavelet transform for tissue displacement.The proposed method was compared with the traditional FIR low-pass filter,IIR low-pass filter and Mean filter.And using data from a tissue-mimicking phantom and liver tissue of healthy volunteers for evaluating,the results show that the proposed method can effectively reduce the noise in the displacement and obtain a better visual effect of strain elastograms and SNR of the tissue displacement.

关 键 词： 超声瞬时弹性成像 应变估计 小波去噪 贝叶斯阈值法 位移

领　　域： [电子电信] [电子电信]