非线性参量B/A超声成像的仿真与仿体实验研究

非线性参量B/A是描述生物组织非线性效应的重要参量,其对组织特性的敏感度较线性参量高出1~2个数量级。将非线性参量B/A用于生物组织成像,更有利于组织定征与医学超声诊断。目前已有的B/A成像效果大多依赖于B/A测量技术的准确性。为了获取较好的B/A成像,通过仿真与仿体实验比较了有限振幅声波法测量非线性参量B/A的几种经典方法,仿真和仿体实验结果均表明:扩展比较法(Extended Comparative Method,ECM)测量准确性高,其测量误差低于3%。运用该方法结合滤波反投影仿真实现B/A参量层析成像,成像结果能较好描述简单组织中的B/A参量分布。

Simulation and phantom studies of the nonlinear parameter B/A ultrasound imaging

The nonlinearity parameter is an important indicator of the nonlinear acoustic effect on biological tissues. Compared with linear parameters, B/A has one to two order of magnitude higher sensitivity to the tissue properties. Using B/A as the tomography parameter of biological tissues is more conducive to tissue characterization and medical ultrasound diagnosis. The existing B/A imaging relies on the accuracy of the B/A measurement. In order to obtain a good B/A imaging result, the comparisons of the classical methodologies for B/A parameter measurement based on the finite amplitude methods are carried out, both in computer simulation and phantom studies. The experimental re-sults show that the extended comparative method （ECM） can provide more accurate B/A measurement with the per-centage error less than 3%Combined with filtered back projection, the ECM is implemented to get the B/A tomogra-phy imaging in simulation environment. The B/A tomography validates that the ECM can get the right distribution of B/A for a simple tissue.