Miniature fiber scanning probe for flexible forward-view photoacoustic endoscopy.

The article focuses on the development and evaluation of a flexible forward-view photoacoustic endoscopy (PAE) probe based on a resonant fiber scanner designed for minimally invasive imaging in narrow internal organ areas. This 5 mm diameter probe integrates a piezoelectric (PZT) bender, fiber cantilever, lens, ultrasound transducer, and coupler, achieving a lateral resolution of 15.6 μm within a 3 mm diameter field-of-view and an imaging speed of 0.5 frames per second. Phantom and in vivo imaging of rat gastrointestinal walls demonstrated clear visualization of vascular networks, indicating the probe’s potential for clinical evaluation of gastrointestinal lesions. The study highlights advantages over traditional fiber-bundle scanning methods by enabling higher spatial sampling in a smaller probe size and suggests future improvements including reduced probe size, increased imaging speed, and enhanced axial resolution.