Transurethral photoacoustic and ultrasonic endoscopic probe developed for bladder cancer diagnosis

Abstract

Minimally-invasive imaging application of photoacoustic (optoacoustic) tomography (PAT) has been mainly focused on gastrointestinal endoscopy or the imaging of cardiovascular and reproductive systems, such as uterus, ovary, and prostate, in relation to the diagnosis of atherosclerotic plaques (e.g., plaques building up in a coronary artery) and the cancers developed in the mentioned core reproductive systems. However, related miniature probe technology could also make a considerable contribution to the diagnosis and post-treatment follow-ups of urinary diseases because PAT can provide unique anatomical, functional, and molecular information, which is not possible with conventional methods. Among related clinical issues, development of a new diagnostic paradigm for the early detection of bladder cancer is urgently needed because this cancer is known very aggressive and lethal if it is found after stage 2 (T2). In this study, we developed a 2.8 mm outer diameter, transurethral photoacoustic and ultrasonic endoscopic probe to contribute to the early diagnosis of bladder cancer. From a live rabbit, we have successfully acquired the first high-resolution 3D vasculature map distributed over an area more than 80% of the bladder wall, which we believe it is a completely new type of image information never acquired from a vertebrate level urinary system before.