Relation between selective alveolo-bronchograms and pulmonary function tests in patients with chronic obstructive pulmonary disease.

We studied the relation between selective alveolo-bronchograms (SAB) and pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD) other than asthma. The SAB were obtained by the technique reported by Nakamura and coworkers (Tohoku J Exp Med 1969; 99:207). First, the relation between SAB and morphologic findings was examined in 14 autopsy lungs in order to confirm the morphologic bases of the shadows. The ring shadows that appeared in the SAB were histologically identified as alveolar ducts in normal lungs and as destroyed parenchymal air spaces in emphysematous lungs. There was a significant correlation between the mean diameter of ring shadow (DR) and the degree of morphologic emphysema (p less than 0.001). This correlation indicated a significant degree of emphysema when the DR exceeded 900 micron. The irregularity index of the airway in SAB also showed a significant correlation to the grade of pathologic abnormalities in the airways (p less than 0.01). Second, SAB were obtained in 64 patients with COPD in whom pulmonary function tests were performed. In these patients, the DR correlated significantly with most of the pulmonary function tests. This correlation was especially high with transfer factor (DLCO/VA). These 64 patients were divided into 2 groups on the basis of the DR: In Group A, DR was more than 900 micron, whereas in Group B, it was less than 900 micron. In Group A, the DR also showed a significant correlation with DLCO/VA and with diffusing capacity (DLCO); in Group B, significant correlations were found in the irregularity index, especially with regard to pulmonary resistance and the ratio of forced expiratory volume in one second to vital capacity.(ABSTRACT TRUNCATED AT 250 WORDS)