In vivo measurement of temperature rise in living rabbit's liver exposed to ultrasound with acoustic radiation force

Abstract

Acoustic radiation force (ARF) has been used for evaluating tissue elasticity, and is generated by longer pulse duration (PD) and higher acoustic pressure than those used in the conventional ultrasound devices. Although the use of ARF produces relatively-high temperature rise in living biological tissue, the thermal effect of ARF is uncertain. In addition, considering application to the diagnosis of liver, the thermal effect in combination use of ARF and contrast agents should also be considered. In order to evaluate these effects, we have developed a temperature measurement system using a thermocouple for experiment on living animal. In this study, the temperature rise in living rabbit's liver exposed to ultrasound with ARF was measured and evaluated by using the developed system. As the results, all of maximum temperature rise within regulation limits was below 1.5 °C. In addition, there was no significant difference between temperature rises in the liver with and without contrast agents.