A comparative study was carried out on the radiographic findings of the proximal and distal portion of the airways by SAB and bronchography in 49 cases with pulmonary emphysema, 4 cases with chronic bronchitis and 15 cases with chronic bronchiolitis.
1) Pulmonary emphysema was characterized by atrophic change of the airway with concomitant narrowing of the diameter of all airways. Panlobular emphysema showed a lesser tendency for the proximal portion of airway to become narrowed compared with centrilobular and mixed type emphysema, and was characterized by uniformly dilation and irregular wall change. Thus, it was surmised that the impairment extended to the entire airway. The centrilobular type showed more marked inflammatory changes in the distal portion of the airways, indicating the involvement of infection factors.
2) Wall irregularity was most conspicuous in the proximal portion of the airways in chronic bronchitis, followed by cylindrical dilatation. Bead-like wall irregularity was seen only in the distal portion of the airways.
3) In chronic bronchiolitis, both proximal and distal portions of the airways showed distinct impairment in many cases. In the distal portion of the airways, inverted funnel-shaped dilatation was particulary noted, suggesting changes due to mucus plugs, and stenosis or obstruction in the lumen of the airways.
4) Comparison of chest roentgenograms and alveolo-bronchograms disclosed the following results. The more marked the morphological changes in the airways, the more reticular, linear and honeycomb shadows appeared on the chest X-ray films. Inverted funnel-shaped dilatation in the distal portion of the airways was often found in the group in which nodular shadows were seen on the chest X-ray films. This dilatation was considered to occur when the impairment of the distal portion of the airways was mild.
5) Common abnormalities in the airways were not obtainedd between pulmonary emphysema, in particular centrilobular type, and chronic bronchiolitis. Comparing chronic bronchitis with chronic bronchiolitis, the wall irregularity of the proximal airways was remarkable in the former, while the latter was characterized by concomitant dilatation and irregularity in all airways. The alveolar pattern was easily visualized in chronic bronchitis, but not in either pulmonary emphysema or chronic bronchiolitis.