High speed in vivo endoscopic photoacoustic and ultrasound dual-modality imaging (Conference Presentation)

Abstract

Colorectal cancer, the third most common type of cancer globally, has ~1.4 million new cases and 694,000 deaths annually. Endoscopic photoacoustic (PA) imaging is a non-invasive imaging modality that provides structural, functional and molecular information while maintaining a deep depth. Several groups have reported different designs of endoscopic PA imaging systems that represent a significant step forward for the characterization of gastrointestinal (GI) cancer. However, these imaging systems are still not adequate for in-vivo clinical translation due to insufficient field-of-view, large probe diameters, and slow imaging speed. Endoscopic dual-modality photoacoustic and ultrasound imaging has the potential for early detection of cancer in the gastrointestinal tract. Currently, slow imaging speed is one of the limitations for clinical translation. In this study, we demonstrate an integrated endoscopic PA and US imaging system. Utilizing a high repetition rate pulsed laser, optimized rotary joint as well as proximal scanning method, this integrated imaging system is able to obtain morphological tissue information and vasculature of the GI tract simultaneously at a high imaging speed up to 50 frames/s (the fastest speed reported to date). We conducted in-vivo animal studies to demonstrate the performance of our imaging system for evaluating the GI tract. The results obtained from the in-vivo rat experiment showed that the typical layered architecture and vasculature can be identified by this integrated system with a high imaging speed.