A 100-200 MHz Ultrasound Biomicroscope

Abstract

Clinical ultrasound imaging systems capable of producing real-time, economical, cross sectional images of soft tissue are in widespread use. The resolution of these system is not sufficient for certain specialised applications. A 100-200 MHz ultrasound system providing resolution from 14-35 [mu]m has been produced. Transducers were custom built using a novel design. The properties of two transducers, one at 100 MHz and the other at 200 MHz, have been characterised and they compare well with theoretical values. A minimum insertion loss of 18 dB has been measured. Real-time images have been obtained at 100 MHz. At 200 MHz higher quality images were created with a slower, zone focus scan. Adequate contrast and penetration are shown in images of ocular tissue, superficial skin and a coronary artery. These examples show the potential for clinical utility of this system in assessing superficial conditions such as corneal disease, melanoma and atherosclerosis.