Functional Lung Imaging Using CT: An Update

Chest CT has become a key component of the diagnostic approach to a wide range of airway and vascular diseases, including asthma, emphysema, chronic airways disease, and pulmonary vascular disorders such as pulmonary embolism. The interaction between ventilation and perfusion is complex but is always aimed at optimal matching to enable efficient gas exchange. If either one or both of these are affected by disease, they have a negative effect on the other. CT is able to define the structure of lung parenchyma, airways, and pulmonary vasculature in great detail. Beyond morphology, increasingly sophisticated scanner and software technology increase the diagnostic scope of CT toward obtaining comprehensive functional information. This paves the way for new understanding of lung function, the effects of various diseases, and the way in which therapeutic interventions have an effect. Greater understanding of the principal components of chest CT and how they are developing into clinical practice is relevant to anyone with an interest in diagnostic chest imaging. Keywords: CT-Spectral Imaging (Dual Energy), Applications-CT, CT-Quantitative, CT-Perfusion, Thorax, Lung © RSNA, 2025.