The Conical Scanner: A Two Transducer Ultrasound Scatter Imaging Technique

Abstract

A new two transducer ultrasound scatter imaging system has been developed. In operation, a large conical transducer generates an ultrasound beam that converges to a sharp line focus in the tissue being imaged. The second transducer is aimed along the axis of the cone and detects scattered ultrasound as a function of time, converting this information into a high resolution image. Excellent focusing properties are maintained over a large depth of field with no increase in the complexity of standard B-scanner electronics. As well, no increase in time is required to generate the image. The performance of a 45° conical scanner is examined theoretically and experimentally. The FWHM of the lateral point response of the scanner remains 0.25 mm over a 5 cm depth of field. Images of phantoms and in vitro breast tissue demonstrate a great improvement in image quality compared with conventional pulse-echo imaging.