反射式非线性声参量层析成像的研究

Investigation of the computed tomography of the acoustic nonlinear parameter in reflection mode

非线性声参量Ｂ／Ａ描述了有限振幅波在媒质中传播的非线性特性，有可能成为生物组织定征的新参量。本文提出了利用复合式换能器进行反射式的非线性参量Ｂ／Ａ层析成像的新方法。利用反射二次谐波的传播理论及有限振幅波插入取代法给出了计算机重建Ｂ／Ａ层析像的理论方法。对部分流体及生物组织进行了计算机模拟成像及实验研究，取得了较为满意的结果。

The acoustic nonlinear parameter B/A describes the nonlinear features of the propagation of the finite0 amplitude sound wave and may be a new parameter for the ultrasound tissue characterization. In this paper, as a new method, the nonlinear parameter B/A computed tomography in reflection mode is proposed by using a compound transducer. Based on the theory of propagation of reflected second harmonics and the insert-substitution method of the finite amplitude sound wave, the theoretical approach for computer reconstruction of B/A tomography in reflection mode is proposed. The computer simulation and experimental images of some fluids and tissues are also presented in this paper, and results coincide well with the sample models.