Experimental study of temperature elevation in a tissue phantom generated by an operating ultrasonic transducer

The temperature elevation in a homogeneous tissue-mimicking material generated by an ultrasonic transducer (focusing or nonfocusing) operating in megahertz frequencies was measured. It was found that in the vicinity of a transducer front face, both transducer surface heating and ultrasound absorption are important sources for tissue heating. As for heating due to ultrasound absorption, the experimental results are compared with theoretical predictions for nonperfused tissue resulting from a Gaussian beam model and from the model used by the NCRP (National Council on Radiation and Measurements).