In vivo hyperthermia effect induced by high-intensity pulsed ultrasound  

作　　者：崔炜程 屠娟 Hwang Joo-Ha 李倩 范庭波 章东 陈静海 陈伟中 

机构地区：[1]Key Laboratory of Modern Acoustics,MOE,and Institute of Acoustics,Nanjing University [2]Center for Industrial and Medical Ultrasound,Applied Physics Laboratory,University of Washington [3]Department of Cardiology of Children's Hospital Boston,Harvard Medical School

出　　处：《Chinese Physics B》2012年第7期352-358,共7页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China (Grant No. 2011CB707900);the National Natural Science Foundation of China (Grant Nos. 11074123, 10974095, 10904068, and 10204014);the Fundamental Research Funds for the Central Universities of China (Grant Nos. 111602040 and 1095020409);the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2011812);the Priority Academic Program Development of Jiangsu Higher Educaton Institutions of China

摘　　要：Hyperthermia effects （39-44 ℃） induced by pulsed high-intensity focused ultrasound （HIFU） have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid tumor. However, previous studies also reported that the cell death occurs when cells are maintained at 43 ℃ for more than 20 minutes. The aim of this study is to investigate thermal responses inside in vivo rabbit auricular veins exposed to pulsed HIFU （1.17 MHz, 5300 W/cm2, with relatively low-duty ratios （0.2%-4.3%）. The results show that： （1） with constant pulse repetition frequency （PRF） （e.g., 1 Hz）, the thermal responses inside the vessel will increase with the increasing duty ratio; （2） a temperature elevation to 43 ℃ can be identified at the duty ratio of 4.3%; （3） with constant duty ratios, the change of PRF will not significantly affect the temperature measurement in the vessel; （4） as the duty ratios lower than 4.3%, the presence of microbubbles will not significantly enhance the thermal responses in the vessel, but will facilitate HIFU-induced inertial cavitation events.Hyperthermia effects （39-44 ℃） induced by pulsed high-intensity focused ultrasound （HIFU） have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid tumor. However, previous studies also reported that the cell death occurs when cells are maintained at 43 ℃ for more than 20 minutes. The aim of this study is to investigate thermal responses inside in vivo rabbit auricular veins exposed to pulsed HIFU （1.17 MHz, 5300 W/cm2, with relatively low-duty ratios （0.2%-4.3%）. The results show that： （1） with constant pulse repetition frequency （PRF） （e.g., 1 Hz）, the thermal responses inside the vessel will increase with the increasing duty ratio; （2） a temperature elevation to 43 ℃ can be identified at the duty ratio of 4.3%; （3） with constant duty ratios, the change of PRF will not significantly affect the temperature measurement in the vessel; （4） as the duty ratios lower than 4.3%, the presence of microbubbles will not significantly enhance the thermal responses in the vessel, but will facilitate HIFU-induced inertial cavitation events.

关 键 词：hyperthermia effects high-intensity focused ultrasound duty ratio ultrasound contrastagents 

分 类 号：R310[医药卫生—基础医学] O426.9[理学—声学]