中文摘要：

寻找一种合适的方法区别正常组织与坏死组织,是癌微波热疗应用中所面临的重要难题。本研究探讨微波热疗过程中组织回波时域的变化,以寻找合适的参数,无创监测热疗组织状态的变化。在原理分析的基础上设计了实验系统,采用微波介入的加热方式,采集超声回波信号,对变性区域做回波幅值时域积分、幅值平方时域积分（能量）和损伤数字减影积分,并分析它们的变化趋势。实验结果表明：生物组织回波的不同方式积分值与加热过程中的组织变性具有相关性,微波热疗前后组织回波的幅值、能量、不均匀性均有增大的趋势。利用超声背向散射积分和反应不均匀度的参数进行监测,可得到较理想的结果。

英文摘要：

It is difficult to find a proper method to distinguish the necrotic tissue from the normal in the application of microwave hyperthermia. This paper discussed the change of ultrasonic echo during microwave hyperthermia in order to find proper parameters to realize noninvasive monitoring. Microwave heating method was used in gathering ultrasonic echo signals. Amplitude integral, energy and subtraction integral were computed. The results showed that the calculated parameters were relevant with tissue necrotic during hyperthermia. The echo amplitude, energy and non-uniformity increased after hyperthermia. Better result could be got by using ultrasonic backscatter integral and heterogeneity parameters to monitor hyperthermia.