Due to the ever increasing interest in the use of non-invasive ultrasonic methods in medical diagnostics on the one hand and the specific effects of ultrasound in medical therapy on the other, the questions of safety and optimal applications are topical and of great importance. For this reason the symposium "Ultrasound Interaction in Biology and Medicine," initiated and supported by the "International Organization of Medical Physics," took place. The organizers were the Institute of Applied Biophysics of the Martin-Luther-University, Halle (Saale), German Democratic Republic, in association...