A Preprocess Method of External Disturbance Suppression for Carotid Wall Motion Estimation Using Local Phase and Orientation of B-Mode Ultrasound Sequences.

Qinghui Zhang,Junqiu Li,Libo He,Zhenping Qiang

doi:10.1155/2019/6547982

Abstract

Estimating the motions of the common carotid artery wall plays a very important role in early diagnosis of the carotid atherosclerotic disease. However, the disturbances caused by either the instability of the probe operator or the breathing of subjects degrade the estimation accuracy of arterial wall motion when performing speckle tracking on the B-mode ultrasound images. In this paper, we propose a global registration method to suppress external disturbances before motion estimation. The local vector images, transformed from B-mode images, were used for registration. To take advantage of both the structural information from the local phase and the geometric information from the local orientation, we proposed a confidence coefficient to combine them two. Furthermore, we altered the speckle reducing anisotropic diffusion filter to improve the performance of disturbance suppression. We compared this method with schemes of extracting wall displacement directly from B-mode or phase images. The results show that this scheme can effectively suppress the disturbances and significantly improve the estimation accuracy.

Highlights

Nowadays, cardiovascular disease (CVD) has become one of the deadliest diseases in the world
It is generally accepted that the early state of a carotid artery is a useful predictor of the risk of both ischemic stroke and coronary heart disease in the asymptomatic population [2, 3]. e increase of arterial wall stiffness is considered a common pathologic mechanism for many factors associated with CVD [4, 5]. erefore, many efforts have been made to measure the stiffness of the carotid arterial wall to assess the degree of atherosclerotic disease for early diagnosis [6, 7]
We removed the part near the arterial wall while keeping the part far away from the wall of a clinical vascular B-mode ultrasound image (Figure 4(a)). en, we used the speckle-reducing anisotropic diffusion (SRAD) filter to preprocess the image. e phantom of the tissue part far from the arterial wall was generated, in which the amplitude of the reflecting wave of each scattering point is set up based on the gray level of the filtered image

Summary

Introduction

Cardiovascular disease (CVD) has become one of the deadliest diseases in the world. E increase of arterial wall stiffness is considered a common pathologic mechanism for many factors associated with CVD [4, 5]. Erefore, many efforts have been made to measure the stiffness of the carotid arterial wall to assess the degree of atherosclerotic disease for early diagnosis [6, 7]. Erefore, the measurement of motions of an arterial wall plays a significant role in revealing the pathogenesis of the atherosclerotic carotid disease [9, 10]. Three main ultrasonic imaging methods were used for measuring displacements of an arterial wall: echo tracking [12, 13], B-mode [14, 15], and M-mode [7, 16]. As for M-mode, its method of obtaining the velocity using the autocorrelation extraction envelope discards phase information which may be useful

Methods

Results

Conclusion