Integrated intravascular ultrasound and photoacoustic imaging scan head.

The combination of intravascular ultrasound and intravascular photoacoustic imaging has been proposed for improving the diagnosis of arterial diseases. We describe a novel scan-head design for implementing such multimodality imaging. The proposed device has the potential to achieve a sufficiently small size for clinical intravascular applications. The design aims for efficient image data acquisition for facilitating real-time three-dimensional imaging and reducing the required laser pulse repetition frequency. The integrated scan head consists of a single-element, ring-shaped transducer for sideward ultrasound transmission, a multimode fiber with a cone-shaped mirror for optical illumination, and a single polymer microring with mechanical scanning. The phantom imaging and some experimental results are presented. A microring array can be realized in the future to achieve high-frame-rate intravascular multimodality imaging.