[Ultrasonic hyperthermia of the animal brain]

The paper is concerned with the methods of ultrasonic hyperthermia of the cerebral tissues and the results of preliminary experiments on animals. Ultrasonic radiators made of piezoceramic plates were employed. Ultrasound frequency was 1.56 and 2.85 MHz. Tissue temperature was measured not less than at 14 points using single and "chain" thermocouples with 5 branches every 5 mm and thermistors. In spite of rather inhomogeneous acoustic fields of the ultrasonic radiators they can be used for obtaining homogeneous temperature distributions in tissues at depths up to 20 mm owing to high thermal conduction of tissues. The experiments have demonstrated a possibility of heating animal tissues up to hyperthermic temperatures by ultrasonic exposure of tissues both in cranial trepanation and through the intact skull.