中文摘要：

为满足粘弹性材料弹性特性非接触定征应用的需求,开展基于最大似然互相关时延估计的超声辐射力弹性成像技术研究。针对传统基于归一化协方差时延估计的超声辐射力弹性成像技术在低信噪比环境下分辨率下降的缺点,该方法以超声辐射力作为驱动力源,非接触作用于待检粘弹性材料上使其产生形变,并利用最大似然互相关时延估计技术分析处理超声回波信号,实现待检材料所产生形变的多分辨率检测,从而确定弹性模量相对值的空间分布图,达到对粘弹性材料弹性特性非接触定征的目的。仿真及试验研究表明,与传统超声辐射力弹性成像技术相比,该方法具有更高的弹性成像分辨率,尤其在低信噪比环境下表现出明显的优势。同时,试验所获得脂肪组织辐射力响应曲线与生物组织的Voigt粘弹性力学理论模型完全吻合,证实了所提方法的可行性和有效性。

英文摘要：

In order to meet the non-contact characterization application requirements of the elastic properties for viscoelastic materials,a kind of acoustic radiation force elasticity imaging technology based on maximum likelihood cross-correlation time delay estimator is proposed.To solve the drawback of the resolution declining in low SNR environment of the traditional acoustic radiation force elasticity imaging method based on normalized covariance time delay estimator,this new technology uses acoustic radiation force as the driving force source to non-contactly act on the tested viscoelastic material and deform it.And the ultrasonic echo signals are processed by maximum likelihood cross-correlation time delay estimator to detect the multi-resolution deformation of the tested material.Then the spatial distribution of the relative elastic modulus value is determined to achieve the non-contact characterization purpose of the elastic properties of viscoelastic material.Simulation and experimental results indicate that the new technology provides a higher elasticity imaging resolution,especially in low SNR environment,compared with conventional acoustic radiation force elasticity imaging technology.Meanwhile,the experimental radiation force response curve of the adipose tissue is completely consistent with the Voigt viscoelastic mechanical model of biological tissues,thus proving the feasibility and effectiveness of the proposed method.