Time-domain solution of the temperature increase induced by diagnostic ultrasound

Presents a complete time-domain solution to estimate the temperature increase induced by pulsed ultrasonic fields, such as those used in diagnostic applications. The authors' computational model includes 3 steps: (1) calculation of the acoustic field, (2) of the rate of heat generation and (3) of the temperature distribution. For step 1 and 3, the acoustic and thermal fields are computed by integrating the known acoustic and thermal Green functions of the homogenous medium, respectively, over the surface of the transducer and over the volume of interest. For step 2, the authors derive a new expression for the instantaneous rate of heat generation. Previous expressions gave only the average rate of heat for a single frequency excitation. The authors finally present computational results of the temperature increase induced by a point source and by a circular focused transducer.