Tapered catheter-based transurethral photoacoustic and ultrasonic endoscopy of the urinary system

Abstract

Early diagnosis is critical for treating bladder cancer, as this cancer is very aggressive and lethal if detected too late. To address this important clinical issue, a photoacoustic tomography (PAT)-based transabdominal imaging approach was suggested in previous reports, in which its in vivo feasibility was also demonstrated based on a small animal model. However, successful translation of this approach to real clinical settings would be challenging because the human bladder is located at a depth that far exceeds the typical penetration depth of PAT (∼3 cm for in vivo cases). In this study, we developed a tapered catheter-based, transurethral photoacoustic and ultrasonic endoscopic probe with a 2.8 mm outer diameter to investigate whether the well-known benefits of PAT can be harnessed to resolve unmet urological issues, including early diagnosis of bladder cancer. To demonstrate the in vivo imaging capability of the proposed imaging probe, we performed a rabbit model-based urinary system imaging experiment and acquired a 3D microvasculature map distributed in the wall of the urinary system, which is a first in PAT, to the best of our knowledge. We believe that the results strongly support the use of this transurethral imaging approach as a feasible strategy for addressing urological diagnosis issues.

Transurethral photoacoustic and ultrasonic endoscopic probe developed for bladder cancer diagnosis

“…In Ref. 26, more than 80% of the bladder region was visualized. Through close analysis, we confirmed that the transverse resolution of the OR-PAE mode was as low as 11 µm, which was enough to resolve capillaries.…”

Photoacoustic imaging plus X: a review

“…To address this concern, the following studies underscore the significant progress made to promote the progress of PAE toward clinical application. 134 , 146 – 149 …”

“…To address this concern, the following studies underscore the significant progress made to promote the progress of PAE toward clinical application. 134,[146][147][148][149] A major difficulty in multimodal PAE lies in achieving efficient light coupling. Wen et al 150 addressed this issue by introducing a disposable PAUS endoscopic catheter prototype and its corresponding power interface unit.…”