[High-resolution computed tomography study (HRCT) in so-called emphysema B. The correlations between the radiogram,...

The results are reported of a prospective study on 28 emphysematous patients with clinical, functional and radiologic correlations. Thirteen of 28 patients had type-B, the clinical "blue and bloater", emphysema. The grade of emphysema was investigated on conventional chest films and on HRCT scans, with a visual scoring system. Hyperinflation was assessed on conventional chest films and correlated with the extent of emphysema on HRCT images and with functional impairment. In our series, the extent of emphysema in B-type patients was markedly lower than in other patients of the same age, with the same smoking habits, dyspnea and functional impairment. Moreover, the incidence of centrilobular involvement was higher, though not statistically significant. The B-type exhibited more severe dilatation of subsegmental pulmonary arteries (76.9% vs. 20% p < 0.001) and a striking incidence of small airway disease (84.6% vs. 26.6%, p < 0.002). This findings may explain the radiographic pattern of "increased vascularity" seen on chest films. Bronchiolectasis and small airway wall thickening are much more frequent in type-B emphysema, together with patchy areas of ground-glass opacity and small peripheral nodules. A close correlation was observed between signs of small airway disease on HRCT images and functional clinical impairment. Thus, the small airway disease might eventually prove to be a more critical factor in causing functional and hemodynamic impairment in B-type emphysema than the actual extent of centrilobular emphysema.