离体组织声学特性对高强度聚焦超声剂量学预测的影响

Effect of in vitro tissue acoustic properties on dose prediction of high intensity focused ultrasound

应用高强度聚焦超声(HIFU)进行临床治疗时,主要依赖于有经验的医生主观确定辐照剂量。术前剂量投放预测一直是一个亟待解决的难题,但如果能准确预测温升变化,建立可靠的温度变化理论模型,将有助于为临床医生提供一定参考。本研究分别从声速、声衰减随温度变化的两个角度,介绍生物组织声学特性发生变化的原因,总结前人实验测得的组织声学特性的相关数据,分析离体牛肝组织声速、声衰减随温升的变化模型。在HIFU治疗中考虑靶区组织的声学特性变化,可为进一步修正HIFU剂量预测的理论模型提供一定理论依据。

At present, using high intensity focused ultrasound(HIFU) for clinical treatment mainly relies on experienced doctors to subjectively determine the irradiation dose. Preoperative dose prediction has always been an urgent problem to be solved.Accurately predicting the change of temperature rise rate and establishing a reliable theoretical model of temperature change could provide some reference for clinicians. Herein the reasons for the change in acoustic characteristics of biological tissues are introduced from two perspectives, namely acoustic velocity and sound attenuation changing with temperature. The relevant data of tissue acoustic characteristics measured by previous experiments are summarized, and the variation models of sound velocity and sound attenuation in in vitro bovine tissue changing with temperature rise are analyzed. The consideration of acoustic characteristics of target tissue in HIFU treatment provides a theoretical basis for the further modification of the theoretical model of HIFU dose prediction.