R. M. Arthur, W. D. Richard, and J. W. Trobaugh, , "A Modular Synthetic-Aperture System for In Vitro Tissue Characterization", Ultrasonic Imaging, in review, 2007.

Abstract

Conventional, real-time pulse-echo imaging systems use focus-and-steer algorithms to produce images, which are optimally focused only at a limited number of pixels. Because synthetic aperture (SA) imaging separates echo acquisition from image generation, images can be produced from a given set of backscattered signals under different assumptions about the nature of the medium being imaged and with different focus modes and apodization schemes. We designed, built, and tested a novel, inexpensive, modular SA system for \emph{in vitro} studies that can acquire echoes from all element pairs in a transducer array with up to 256 elements. We tested a 64-channel version, which acquired echoes from $64^2$ (4096) source-sensor pairs in about one minute. This system was used to assess image quality of conventional systems and to study temperature effects on tissue. Art work for the board, the board schematic, and parts list are available upon request.

Keywords:  Diagnostic ultrasound; noninvasive thermometry; synthetic aperture; tissue characterization

Support:  National Institutes of Health grants R01-CA107588 and R21-CA90531 from the National Cancer Institute and the Wilkinson Trust at Washington University in St. Louis.