Dual-Scanning Photoacoustic Endomicroscopy for High-Speed Gastrointestinal Microvascular Imaging

Photoacoustic endomicroscopy enables high-resolution imaging of deep microvasculature within the gastrointestinal wall using modulated laser pulses with point-by-point scanning. However, conventional scanning mechanisms frequently encounter difficulties in balancing imaging speed and field of view, particularly when imaging the peristaltic gastrointestinal tract. To address this challenge, we propose a dual-scanning photoacoustic endomicroscopy with an adjustable focal plane and an ultrafast imaging speed. The probe features two distinct scanning modes: 360° angular scanning providing a wide field of view, and regional spiral scanning offering high image quality. We demonstrated the capability of this probe through imaging both phantoms and rat rectums. The results from the rectal injury model demonstrate the applicability and sensitivity of the probe. Overall, this study offers new perspectives for expanding the applications and clinical potential of photoacoustic endomicroscopy.