高强度聚焦超声治疗中热波效应和声热耦合研究进展

Thermal wave theory and thermo-acoustic coupling in high intensity focused ultrasound treatment

高强度聚焦超声(HIFU)治疗剂量学研究是HIFU技术的一个重要科学问题。由于HIFU治疗是一种高热通量、加热时间短的治疗方式,通过非线性声传播与生物传热相耦合的模型来研究HIFU治疗的温场分布必须考虑如下因素:(1)由于靶区组织的温升具有明显的热波效应,需要对经典生物热传导方程进行修正;(2)HIFU治疗中的组织声热耦合效应变得更为复杂,这包括生物组织温度上升使得生物组织的声学性质发生动态变化(即热声透镜),以及液体汽化所产生的蒸汽泡对温度场产生影响。本文综述了影响HIFU治疗温场分布的上述因素,以期对HIFU治疗的生物物理机制有更深的认识。

The study of therapeutic dosimetry is an important scientific issue in the high intensity focused ultrasound（HIFU）treatment. Because of the high heat flux and short heating time in HIFU treatment, the following factors must be considered for researching the temperature distribution by using the coupling model of nonlinear acoustic propagation and bioheat transfer. The typical bioheat transfer equation was needed to be modified because of the obvious thermal wave effect in target tissue; the coupling effect of acoustic with thermal in tissue became more complicated in HIFU treatment, including dynamic change of acoustical properties in biological tissue caused by temperature rise, and the influence of vapour bubbles caused by liquid vaporization on temperature field. The above-mentioned factors which influenced temperature distribution of HIFU treatment were reviewed in the paper to deepen the understanding of biophysical mechanism of HIFU treatment.