In Vivo Ultrahigh-Resolution Quantitative OCT Imaging in Lungs

Pulmonary diseases such as asthma and chronic obstructive pulmonary disease (COPD) are significant global health challenges, characterized by extensive remodeling of small airways. Conventional imaging modalities like spirometry and computed tomography are limited in their ability to visualize these microstructural changes, hindering effective evaluation of disease progression and treatment outcomes. In this study, we developed and utilized an 800-nm ultrahigh-resolution diffractive optical coherence tomography (OCT) system for in vivo imaging of small airway microstructures. The system achieves a lateral resolution of approximately 7.2 μm and an axial resolution of 1.7 μm in tissue, allowing detailed visualization of critical airway components, including smooth muscle, epithelium, basement membrane, and cartilage. We employed a 1.8-mm-outer diameter imaging catheter to access and image small airways. Validation through comparative histological analysis confirmed the accuracy of our OCT system. Furthermore, we utilized deep learning algorithms to achieve automated segmentation of airway microstructures. Our results demonstrate the potential of this advanced imaging tool in providing new insights into airway remodeling in diseases such as asthma and COPD, as well as in assessing the efficacy of therapeutic interventions.