The airway dimension in ordinary human lungs. A standardized morphometry of lung sections.

In chronic obstructive pulmonary disease, obscurities remain in the degree of obstruction and its distribution in the airway tree. To overcome these obscurities, a technique was introduced to estimate the original diameter of an airway in lung sections; this technique involved measurement of the accompanying artery. Ordinary lungs had been obtained at autopsy from 17 deceased patients of various ages; from these lungs, 695 pairs of airways and pulmonary arteries were subjected to computer-assisted measurement of their diameters: the whole range of airways from the segmental bronchi to the respiratory bronchioles was sampled. We proved that a log-log regression existed between the diameter of an airway and that of the pulmonary artery; this regression was sufficiently close to allow one to estimate the diameter of an airway from the diameter of the pulmonary artery, even in chronic obstructive pulmonary disease, in which airways are usually strongly stenosed or dilated. In an additional study of three lungs with various types of chronic obstructive pulmonary disease, the diameters of the pulmonary arteries were shown to remain essentially unaffected.