[Measurement of the posterior wall of the intermediate bronchus. Diagnostic value].

The posterior wall of the intermediate bronchial trunk (PWIB) is visible in most cases on profile thoracic radiographs. A retrospective study showed that it is thickened (over 3 mm) in cases of cardiac failure, right pneumonitis, adenopathy, right bronchopulmonary neoplasias and pulmonary fibrosis, either acute or chronic. The latter etiology had not yet been described in the literature. In our experience, assessment of the thickness of the intermediate bronchus provides a reliable criterium of response to treatment. The pathological mechanisms of intermediate bronchus thickening due to an increase of bronchial wall thickness or of peribronchial interstitial tissue are discussed.