Document Type : Original Paper
School of Information Science and Engineering, Changsha Normal University, Changsha 410100, China
School of Physics and Electronics, Central South University, Changsha 410083, China
As a non-invasive method of tumor hyperthermia, high intensity focused ultrasound (HIFU) has been widely used in the treatment of various solid tumors in recent years. The purpose of this study was to investigate the effect of HIFU combined with ethanol on biological tissue lesion and its effectiveness.
Materials and Methods
Firstly, 0.5ml 95% ethanol was injected into the porcine liver tissue in vitro, then HIFU was used to irradiate porcine liver, the B-mode ultrasound and needle hydrophone were used to monitor the cavitation, and a thermocouple was used to measure the focal temperature in real time. The ultrasonic signal scattered at the focal point of HIFU irradiation was collected by the fiber hydrophone, and the attenuation coefficient was calculated. Finally, the attenuation coefficient was input into the Khokhlov-Zabolotskaya-Kuznetov (KZK) equation and combined with the Pennes equation, the thermal lesion of porcine liver was simulated by MATLAB software.
The length of long axis of the lesion area simulated by the attenuation coefficient of cavitation was closer to the length of long axis of the actual measured lesion area with ethanol injection, but the length of short axis of the simulated lesion area was smaller than that of the measured lesion area. However, the length of long axis of the lesion area simulated by the attenuation coefficient of cavitation was larger than the length of long axis of lesion area simulated by the attenuation coefficient of liver at room temperature, and the same result was obtained for the length of short axis.
HIFU combined with ethanol can produce larger lesion to biological tissues and improve the therapeutic effect.