Development of an agar phantom adaptable for visualization of thermal distribution caused by focused ultrasound

To analyze the ultrasound power and exposure time in medical treatment, the temperature distribution due to the ultrasound must be measured. In this study, an agar phantom adaptable for visualization of thermal distribution was developed. Thermochromic particles were used to visualize the thermal distribution in the phantom instead of human tissue. The ultrasound field was focused by a concave-type transducer in the phantom, and the color pattern change with the change in temperature was observed.