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Evaluation of airways in obstructive pulmonary disease using high-resolution computed tomography.

Technical advances in medical imaging have provided an opportunity to examine the airways of the lung more accurately than ever before. The aim of this article is to review the use of computed tomography (CT) and more particularly, High-resolution CT (HRCT) in the investigation of airway structure and function in health and disease. Although we review both qualitative and quantitative studies, the quantitative studies are emphasized because of the enormous potential provided by the digital data on which this imaging modality is based. HRCT has allowed visualization of airways and parenchyma in much greater detail than conventional CT and plain radiography and has made possible the investigation of the site, magnitude, and distribution of airway narrowing in vivo . Technical improvements have increased the spatial resolution of HRCT, making it theoretically possible to examine small airways. Because technical factors and the methods of analysis significantly influence the quality of HRCT images as well as their quantitative interpretation, we start with a brief review of the recommended methods.