Tomographic Imaging of Small Airways

Three-dimensional lung imaging has become a routine investigation in clinical medicine. The clinical needs have driven the development of tomographic imaging, as much as the research into better imaging itself has driven some of the improvements in imaging. There has been a steady stream of publications in which tomographic imaging has been used to measure small airway structure and function in obstructive airway diseases. These data provide unique insights and information on pulmonary physiology because they provide direct measurements of the airways, rather than global information from lung function, and they provide topographical information, i.e. spatial distribution. Their utility is magnified when combined with other information such as lung function. In this article, the application of topographic imaging in relation to small airway function is discussed.