Experimental and Numerical Analysis of Temperature Rise in Phantom Caused by High-Intensity Focused Ultrasonic Irradiation

For the safe usage of ultrasonic diagnosis, it is important to research the temperature rise in the human body caused by ultrasonic irradiation. The temperature increase in the human body has been estimated by numerical analysis and an experiment using a tissue-mimicking phantom. In this study, we developed a method for the three-dimensional nonlinear simulation of temperature rise caused by intense ultrasonic irradiation. The sound fields and thermal distributions were calculated by the nonlinear finite difference time domain (FDTD) method and heat conduction equation (HCE) method, respectively. The sound fields and waveforms in water were measured using a hydrophone. The thermal distributions caused by ultrasonic irradiation in the phantom were measured using a thermal camera. The simulation and experimental results of the sound field and thermal distribution were in good agreement. The maximum temperature increase caused by focused ultrasonic irradiation in the phantom was accurately estimated. (c) 2013 The Japan Society of Applied Physics