摘要
热疗在肿瘤消融、高血压治疗等方面有重要应用价值。对热疗过程进行温度监控有利于实施合理的治疗规划,同时可提高治疗的安全性、减少副作用。利用基于超声回波偏移的热应变测温理论进行二维温度估计是一种常用的超声测温方法。但该理论基于组织热膨胀及声速随温度线性变化的假设,适用的温度测量范围一般限于37℃-50℃。该文基于升温组织的物理参量非线性变化,提出了基于非线性超声热应变评估温度变化的模型。在基于活体猪肾周脂肪的微波加热实验中,该文利用上述模型结合动态帧选取算法和自适应滤波,对活体的呼吸、心跳运动进行抑制,减小二维温度图像中的噪声。所得结果表明运动补偿效果良好,对于温升范围不超过30℃的情况,测温误差在2.5℃以内。
Thermal therapies are playing important roles in tumor ablations and treatments of hypertension,during which in vivo thermometry is crucial for making treatment plans,improving the safety and reducing potential side effects.Two-dimensional thermal strain imaging(TSI)based on ultrasonic echo-shifts has recently attracted much interests,but is limited by the assumption therein that the thermal expansion and sound velocity are linear functions of tissue temperature.As a result,the temperature elevation range of TSI is often restricted to 37℃–50℃.In this work,the thermal expansion and sound velocity are assumed as nonlinear functions of temperature,and a nonlinear TSI model is proposed.Combined with a dynamic frame selection algorithm and adaptive filtering,which help to suppress the respiration and cardiac movement and reduce the temperature noise,the nonlinear TSI model is applied for thermometry in a microwave heating experiment targeting the perirenal fat of living pigs.In the results reported here,with good motion compensation is validated,while the temperature estimation error is within 2.5℃ for 30℃ tissue temperature rise.
作者
孙彪
郭霞生
屠娟
章东
SUN Biao;GUO Xiasheng;TU Juan;ZHANG Dong(School of Physics,Nanjing University,Nanjing 210093,China;The State Key Laboratory of Acoustics,Chinese Academy of Science,Beijing 100190,China)
出处
《应用声学》
CSCD
北大核心
2021年第1期44-50,共7页
Journal of Applied Acoustics
基金
国家自然科学基金项目(81627802,11934009,11674173,11774166,11774168,11874216,11974179)
声场声信息国家重点实验室开放课题(SKLA202012)。
关键词
超声测温
热应变成像
运动补偿
Ultrasound thermometry
Thermal strain imaging
Motion compensation
作者简介
孙彪(1999–),男,贵州六盘水人,硕士研究生,研究方向:生物组织中的超声测温;通信作者:屠娟,E-mail:juantu@nju.edu.cn。
