The airways comprise the hierarchical tubular structure that leads the air into the lungs, namely the trachea and the bronchi. A well know challenge in the pulmonology field is the automatic segmentation of the airways from tomographic images. We have developed a region growing algorithm in which the segmentation is iteratively bounded by cylinders. These cylinders limit the expansion of leaks, a common problem with region growing, and make them more easily detectable through the use of anatomical information about the airways.