HIGH-RESOLUTION ACOUSTICAL IMAGING APPLICATIONS IN DERMATOLOGY

High resolution acoustical imaging involves hard constraints for the u ltrasonic probes which are used: a high resonance central frequency, a very great bandwidth, a good sensitivity and a strong focussing of th e beam. The system which is described uses a very broad band 17 MHz ce ntral frequency transducer. An acoustic lens focuses the ultrasonic be am with a focal distance of 7 mm. The movement of the transducer in fr ont of the skin provides a 6 mm wide and 5 mm deep cross-section with 15 images/s, a 0.08 to 0.1 mm axial resolution and a 0.2 to 0.3 mm lat eral resolution in the focal zone. The device was tested on fantoms in water and in vivo with applications in Dermatology.