 Videobronchoscopy is an essential diagnostic procedure for evaluation of the central airways and pivotal for the diagnosis and staging of lung cancer. Further technological improvements have resulted in high definition HD images and advanced image enhancement technique i-scan. An earlier study NCT01676012 has indicated that HD bronchoscopy in combination with i-scan technology is superior to HDWL white light for detecting endobronchial vascular changes. In this study we aim to correlate these vascular changes to histology and hypothesize that these vascular changes are related to pre- malignant changes and that the addition of i-scan is superior to HD WL. 