Elasticity assessment of intestinal tissues using endoscopic optical coherence elastography

Abstract

Strain-based optical coherence elastography (OCE) is a functional imaging modality derived from optical coherence tomography (OCT), which evaluates biomechanical properties by measuring tissue strain. However, conventional Doppler phase-based strain estimation is highly susceptible to phase wrapping, particularly under conditions of unstable scanning speed, which is often exacerbated by non-uniform rotational distortion (NURD) in proximally driven endoscopic probes. To overcome these limitations, we propose a distal rotary scanning endoscopic OCE system integrated with a balloon catheter. By combining balloon inflation-induced excitation with circumferential scanning, the system enables stable and uniform elastography imaging of intestinal tissue while mitigating NURD-related artifacts. Displacement fields are estimated by calculating inter-frame phase differences of OCT images, based on which radial strain maps are reconstructed, thereby simplifying the phase-unwrapping process. Experiments conducted on tissue-mimicking phantoms and ex vivo porcine intestines confirm the feasibility of the proposed method. The results indicate that the system can simultaneously capture high-resolution structural images and radial strain information from localized intestinal tissues, demonstrating significant potential for clinical applications in the early diagnosis and therapeutic monitoring of intestinal diseases.