MULTI-FREQUENCY ULTRASONIC IMAGING AND THERAPY

摘要

Ultrasound imaging apparatus comprising: a first source of ultrasound energy at a first frequency which irradiates a region of a body; a second source of ultrasound energy at a second frequency which irradiates said region of the body, wherein the energy at the first and second frequencies at the region are sufficient to cause energy at at least one of a third frequency and a fourth frequency to be generated in the region, said third frequency being the difference between the first and second frequencies and the fourth frequency being the sum of the first and second frequencies; and a directional antenna which receives energy at one of the third and fourth frequencies from the region and provides an image signal in response thereto.