Rat liver and rabbit liver and kidney were exposed to focused ultrasound of 312 w/sq cm (rat) and 900 w/sq cm (rabbit) by direct application of the ultrasound transducer to the surface of the organ exposed. A discrete, narrow, cylindrical zone of tissue necrosis to a depth of approximately 2 cm could be induced in the tissue exposed to the ultrasound. Lesions thus produced were well tolerated and tended to be resorbed over a period of several weeks without evidence of hemorrhage, infection, or adverse systemic effect. In rabbit liver, a linear zone of necorsis was induced by linear movement of the transducer. Development of the use of local high-intensity ultrasound may broaden the clinical scope of thermal destruction of cancer beyond that accomplished by electrocoagulation or cryosurgery.
Linke CA, Carstensen EL, Frizzell LA, Elbadawi A, Fridd CW. Localized Tissue Destruction by High-Intensity Focused Ultrasound. Arch Surg. 1973;107(6):887-891. doi:10.1001/archsurg.1973.01350240053015