 Endoscopic confocal endomicroscopy can detect and classify common bronchiolar and alveolar pathological conditions in real time. Specifically, we hypothesize that confocal endomicroscopy images of bronchiolar and alveolar structures during standard bronchoscopy could help to recognize and classify the presenceabsence of acute rejection andor bronchiolitis obliterans syndrome in lung transplant recipients. This technology could also identify the histological characteristics lung diseases such as interstitial, obstructive or vascular end stage lung diseases, and thus lead to more efficient, safer and more accurate diagnosis of these lung conditions during routine bronchoscopies. 