通过Monte Carlo 方法研究了经超声场调制的散射光在双层和三层生物组织中的传播规律。给出了超声调制的散射光及其调制深度与介质厚度、吸收系数、散射系数和各向异性因子的关系。Monte Carlo 模拟结果表明,经超声调制后的散射光会随着超声区外生物组织的光学参数和组织结构的变化而变化,而调制深度只与超声区的声光特性有关,与超声区外生物组织的光学特性、组织结构等无关,是超声调制光学成像技术最终进行图像处理与重建的关键物理量。

The propagation of ultrasound modulation scattering signal in two-layered and three-layered biological tissue was studied with Monte Carlo simulation. The relations with the modulation scattered light intensity and its modulation depth contributed by the thickness,absorption coefficient,scattering coefficient and anisotropy coefficient of homogeneous and layered tissue were figured out. The results of Monte Carlo simulation show that the modulation scattering light is dependent on the optical properties and configuration of tissue,but the modulated depth of the modulated light doesn′t change in the propagation and is only dependent on the optical and ultrasonic properties of biological tissue within the ultrasound zoom. So the modulated depth is a key factor in ultrasound-modulated optical tomography. These works will conduce to reconstruct the tissue imaging effectively and reliably.