Research of Endobronchial Optical Coherence Tomography in Pre-COPD

This study uses a camera technology called Optical Coherence Tomography (OCT) — similar to an ultrasound but using light — inserted through a breathing tube into the airways to look at early structural changes in the lungs. Researchers want to find signs of pre-COPD (early-stage lung damage before major symptoms appear). **You may be eligible if...** - You are a non-smoker with normal lung function - A CT scan found a small lung nodule, but you have no other lung diseases **You may NOT be eligible if...** - You have any condition that makes a bronchoscopy (a tube inserted into your airway) unsafe - You are already enrolled in another clinical study - You cannot cooperate with the examination or follow-up visits - You are pregnant Talk to your doctor to see if this trial is right for you.