Morphology of the Aging Lung on Computed Tomography

As the population becomes older, recognition of the pulmonary computed tomography (CT) features of "normal" aging is likely to become increasingly important to differentiate from clinically significant disease. Several studies have evaluated the appearances of the lung parenchyma and large and small airways in asymptomatic older individuals and found increased prevalence of cysts, reticular pattern, air trapping, bronchial dilation, and bronchial wall thickening in older individuals compared with younger individuals. Objective differences in CT lung parenchymal attenuation and complexity have also been described. The CT appearances of the aging lung are illustrated, and the histopathologic and functional changes are discussed.