Advances in high-resolution computed tomography (CT) imaging are making a full three-dimensional analysis of the lungs feasible. In particular, airway morphology can be studied in vivo and quantitative metrics of airway size and shape can be extracted. The thickening process associated with the inflammatory response in the diseased lung can be quantified by means of image processing techniques that extract the airway lumen and airway wall. In this article, we give an overview of these imaging techniques and their diverse nature. We also offer a comprehensive view of the analysis pipeline for three-dimensional airway trees and a validation framework that is needed to compare different techniques.