Implementation of a novel 288-element dual-frequency array for acoustic angiography: in vitro & in vivo characterization

Acoustic angiography is a superharmonic contrast-enhanced ultrasound imaging method that produces high-resolution, three-dimensional maps of the microvasculature. Previous acoustic angiography studies have used two-element, annular, mechanically actuated transducers (called “wobblers”) to image microvasculature in preclinical tumor models with high contrast-to-tissue ratio and resolution, but these early wobbler transducers could not achieve the depth and sensitivity required for clinical acoustic angiography. In this work, we present a system for performing acoustic angiography with a novel dual-frequency transducer – a coaxially stacked dual-frequency array. We evaluate the dual-frequency array system both in vitro and in vivo and demonstrate improvements in sensitivity and imaging depth up to 13.1 dB and 10 mm, respectively, compared to previous wobbler probes.