A Newtonian rheological model for the interface of microbubble contrast agents
A Newtonian rheological model for the interface of microbubble contrast agents
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DOI：
10.1016/s0301-5629(03)01051-2
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发表时间：
2003-12-01
影响因子：
2.9
通讯作者：
Sarkar, K
中科院分区：
文献类型：
--
作者：
Chatterjee, D;Sarkar, K
封装微泡造影剂动力学的定量模型将成为超声造影（美国）中的一个有价值的工具。这样的模型必须具有对广泛变化的频率和压力幅度的预测能力。我们开发了一种新的造影剂模型，并成功研究了其对各种操作参数的适用性。封装被建模为厚度无穷小的复杂界面。假设界面具有表面粘度和界面张力的牛顿流变学，并导出了修正的瑞利-普莱塞方程。多种造影剂（Albunex(R)、Optison(R) 和 Quantison(R)）的流变参数（表面张力和表面膨胀粘度）是通过将线性模型动力学与实验获得的衰减数据相匹配来确定的。详细研究了 Optison(R) 的模型行为（表面张力 0.9 N/m 和表面膨胀粘度 0.08 msP）。具体来说，我们对拟合在线性状态下的模型进行了详细的询问，以进行非线性预测。与现有模型相比，新模型捕捉到了 Shi 等人观察到的 Optison(R) 的特征次谐波发射。 （1999）。使用散射与衰减之比（STAR）对气泡行为进行了详细的参数研究。它表明封装极大地减少了共振频率对散射截面的影响，这表明了改进非共振频率下成像的可能方法。本模型的预测能力表明它可用于表征不同的代理并设计新的代理。 （电子邮件：sarkar@me.udel.edu） (C) 2003 年世界超声医学生物学联合会。
A quantitative model of the dynamics of an encapsulated microbubble contrast agent will be a valuable tool in contrast ultrasound (US). Such a model must have predictive ability for widely varying frequencies and pressure amplitudes. We have developed a new model for contrast agents, and successfully investigated its applicability for a wide range of operating parameters. The encapsulation is modeled as a complex interface of an infinitesimal thickness. A Newtonian rheology with surface viscosities and interfacial tension is assumed for the interface, and a modified Rayleigh-Plesset equation is derived. The rheological parameters (surface tension and surface dilatational viscosity) for a number of contrast agents (Albunex(R), Optison(R) and Quantison(R)) are determined by matching the linearized model dynamics with experimentally obtained attenuation data. The model behavior for Optison(R) (surface tension 0.9 N/m and surface dilatational viscosity 0.08 msP) was investigated in detail. Specifically, we have carried out a detailed interrogation of the model, fitted in the linear regime, for its nonlinear prediction. In contrast to existing models, the new model is found to capture the characteristic subharmonic emission of Optison(R) observed by Shi et al. (1999). A detailed parametric study of the bubble behavior was executed using the ratio of scattering to attenuation (STAR). It shows that the encapsulation drastically reduces the influence of resonance frequency on scattering cross-section, suggesting possible means of improvement in imaging at off-resonant frequencies. The predictive capability of the present model indicates that it can be used for characterizing different agents and designing new ones. (E-mail: sarkar@me.udel.edu) (C) 2003 World Federation for Ultrasound in Medicine Biology.