Ultrasound responsive micro-composite markers

Abstract

Ultrasound imaging is a non-invasive, non-radioactive, and low cost technology for diagnosis and identification of implantable medical devices in real time. Developing new ultrasound activated coatings is important to broaden the utility of in vivo marking by ultrasound imaging. Ultrasound responsive macro-phase segregated micro-composite thin films were developed to be coated on medical devices composed of multiple materials and with multiple shapes and varying surface area. The macro-phase segregated in films having silica micro-shells in polycyanoacrylate produces strong color Doppler signals with the use of a standard clinical ultrasound transducer. Electron microscopy showed a macro-phase separation during slow curing of the cyanoacrylate adhesive, as air-filled silica micro-shells were driven to the surface of the film. The air sealed in the hollow space of the silica shells acted as an ultrasound contrast agent and echo decorrelation of air exposed to ultrasound waves produces color Doppler signals.