Real-time optical-resolution photoacoustic endoscope

Abstract

Currently, the reported endoscopic system cannot meet the necessary conditions for real-time and optical-resolution clinical application simultaneously. In this study, by utilizing a high-repetition-rate laser and optimizing the overall structure of the probe, a real-time optical-resolution photoacoustic endoscope was developed, which could image targets in real time while maintaining a relatively constant lateral resolution. The endoscopic system has a best-resolution of 19 μm and a real-time imaging speed of 25 Hz. Experimental results demonstrate that this approach will push the promotion and commercialization of photoacoustic endoscopic imaging in a variety of preclinical and clinical applications.

Transurethral photoacoustic and ultrasonic endoscopic probe developed for bladder cancer diagnosis

“…To realize this approach, the developed probe features a distal tip with a tapered structure and adequate flexibility for smooth transurethral introduction to the bladder. Moreover, it is implemented using optical-resolution (OR) PA endoscopy (PAE) [13][14][15][16][17] rather than conventional acoustic-resolution PAE [18][19][20][21][22] to provide high-resolution vasculature images. It is also equipped with a traditional endoscopic ultrasound (EUS) [23,24] imaging function to provide information on tissue density distribution.…”

“…Given that the human urethra is anatomically curved, we believe that such a feature is crucial for future clinical use. The key advantage of the transurethral approach to imaging is that it is possible to acquire high-resolution vasculature images by applying the OR-PAE principle [13][14][15][16][17]. To achieve a tight optical focus at the desired working distance for OR-PAE, we applied a GRIN lens with a 0.5 mm outer diameter and ~0.1 pitch (GRINTECH, Germany).…”

Tunable spatiotemporal resolution photoacoustic microscopy by combining quasi-periodic scanning and register-fusion algorithm

“…PAM achieves a rich optical contrast with 100% sensitivity; moreover, it exhibits good biological safety owing to its nonionizing radiation, and can sensitively reveal structural and functional information of biological tissues. PAM has great application potential in biomedicine fields, including organology, 2) histology, [3][4][5] cytology, [6][7][8] vascular biology, [9][10][11][12][13][14][15] oncology, [6][7][8][9][10][11][12][13][14][15][16][17][18] neuroscience, 19,20) ophthalmology, 21,22) stomatology, 23,24) and dermatology. 25) PAM imaging usually relies on a point-by-point scanning scheme.…”

“…The spatial resolution and temporal resolution of a PAM are both highly related to the design of the scanning path. Theoretically, the spatial resolution in the lateral direction of a PAM depends on the size of the optical focus (opticalresolution PAM) [8][9][10]13,14,18,24,28) or the acoustic focus (acoustic-resolution PAM). 2,3,13,17,20,25) However, if the scanning step size is larger than the laser spot or acoustic focus, the practical spatial resolution of the image depends on the scanning line spacing.…”

Wideband subwavelength acoustic edge detection via trapped modes with breaking structural periodicity

“…A coustic imaging has significant potential for a variety of applications including non-destructive evaluation, 1) medical ultrasonic diagnostics, 2) and photoacoustic imaging, 3,4) etc. For any wave-based imaging system, the imaging resolution is subject to the diffraction limit.…”