Longitudinal chest x-ray changes in normal men.

To determine the changes on chest x-ray attributable to the aging process, we evaluated cardiovascular and pulmonary structures on two standard postero-anterior chest x-rays taken at least 10 years apart (M = 16.9 years) in 67 carefully screened healthy men initially aged 23 to 76 years. The aortic knob diameter increased in 79% of subjects. Although mean cardiothoracic ratio increased overall, only 3% of men developed a cardiothoracic ratio greater than .50, and none exceeded .51. Pulmonary abnormalities on initial chest x-ray consisted mainly of hyperinflation (27%) and increased markings (19%), both of which doubled in prevalence during follow-up. Kerley B lines and enlarged pulmonary arteries were rare initially but increased three- to five-fold. The prevalence of these findings did not differ between smokers and nonsmokers. Based on commonly accepted x-ray criteria, chronic obstructive lung disease was suggested in 15% of the initial films and 21% of the final films despite the absence of clinical or spirometric abnormalities.