Endoscopic high-resolution autofluorescence imaging and OCT of pulmonary vascular networks.

High-resolution imaging from within airways may allow new methods for studying lung disease. In this work, we report an endoscopic imaging system capable of high-resolution autofluorescence imaging (AFI) and optical coherence tomography (OCT) in peripheral airways using a 0.9 mm diameter double-clad fiber (DCF) catheter. In this system, AFI excitation light is coupled into the core of the DCF, enabling tightly focused excitation light while maintaining efficient collection of autofluorescence emission through the large diameter inner cladding of the DCF. We demonstrate the ability of this imaging system to visualize pulmonary vasculature as small as 12 μm in vivo.