First in vivo rat colorectum imaging result of the integrated photoacoustic and ultrasonic endoscopic mini-probe system

Abstract

We have successfully acquired first in vivo images from a rat colorectum by using the 3.0-mm outer diameter integrated photoacoustic and ultrasonic endoscopic mini-probe system that we introduced in 2019 ABC conference. As previously presented, the system featured the ~1.8-m long torque coil-based proximal actuation mechanism, which enables intra-instrument channel use, and the quasi-optical-resolution photoacoustic imaging capability. In the recent progress, we could confirm that, although the ultrasound image provided deeper imaging, only the photoacoustic image revealed a high-resolution microvasculature distributed in the rat colorectum. The result suggests that our technique could provide more convincing information in relation to the diagnosis of various types of gastrointestinal cancers based on the photoacoustically added vasculature information.