基于磁感应磁声检测的高强度聚焦超声治疗实时温度监测  

Real-time temperature monitoring for high-intensity focused ultrasound therapy based on magnetoacoustic measurements with magnetic induction

作　　者：丁鹤平[1] 郭各朴[1] 王佳伟[1] 郭余庆 王军[2] 李禹志 马青玉[1] DING Heping;GUO Gepu;WANG Jiawei;GUO Yuqing;WANG Jun;LI Yuzhi;MA Qingyu(School of Physics and Technology,Nanjing Normal University,Nanjing 210023,Jiangsu,China;Jiangsu Nengjian Electromechanical Industrial Co.,Ltd,Taizhou 225327,Jiangsu,China)

机构地区：[1]南京师范大学物理科学与技术学院,江苏南京210023 [2]江苏能建机电实业集团有限公司,江苏泰州225327

出　　处：《陕西师范大学学报（自然科学版）》2019年第6期72-79,共8页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国家自然科学基金(11934009,11974187,11604156);江苏省自然科学基金(BK20161013);中国博士后科学基金(2016M591874)

摘　　要：结合磁感应磁声层析成像和超声治疗技术,基于生物组织的电阻抗-温度关系,利用高强度聚焦超声(HIFU)治疗中焦域的电阻抗变化开展了实时温度监控与疗效评估研究。基于生物组织中的聚焦声场和温度场、电磁脉冲所产生的磁声激励和声辐射理论,利用亥姆霍兹波动方程、生物热传导Pennes方程和磁感应磁声检测的基本理论,研究了HIFU焦域的声场和温度场以及电导率分布,模拟了HIFU治疗过程中焦域的磁声声源分布。进一步考虑换能器响应特性,仿真得到磁声声压和磁声声波信号,分析了磁声波簇幅值及其导数随HIFU治疗时间的变化规律,证明HIFU焦域在规定范围内(径向和轴向分别为±0.46 mm和±2.2 mm)温度达到69℃时,组织发生凝固性坏死,此时的磁声波簇幅值的导数达到最大值。研究结果为温度监测提供了一种灵敏快捷的测量方法,促进其在HIFU治疗实时疗效评估和剂量控制中的应用。By combining the magnetoacoustic tomography with magnetic induction(MAT-MI)with the ultrasound therapy,real-time temperature monitoring and treatment efficacy evaluation for the focal region in high-intensity focused ultrasound(HIFU)are investigated based on the impedance-temperature relationship of biological tissues.On the basis of the theories of the focused acoustic and temperature fields and the principles of magnetoacoustic excitation and radiation,the distributions of the acoustic,temperature and electrical conductivity in the focal region area are studied by solving the Helmholtz wave equation and the Pennes equation.The process of magnetoacoustic measurements during HIFU therapy is simulated based on the theory of MAT-MI.With the distributions of magnetoacoustic sources in the focal region,the transducer detected magnetoacoustic pressure and cluster are simulated.The dependences of the amplitude peak of the cluster and the corresponding derivative with respect to the treatment time during HIFU therapy are analyzed.It is proved that irreversible thermo-coagulations occur when the temperature in the focal region with the sizes of±0.46 mm and±2.2 mm in the radial and axial directions reaches 69℃.The maximum value of the derivative of the amplitude peak of the cluster provides a convenient and sensitive indicator for temperature monitoring,which might promote potential applications in real-time treatment efficacy evaluation and accurate dose control for HIFU therapy.

关 键 词：高强度聚焦超声 磁感应磁声检测 电阻抗-温度关系 温度监测 疗效评估 

分 类 号：O426.4[理学—声学]