Air bronchogram

An air bronchogram is defined as a pattern of air-filled bronchi on a background of airless lung. An air bronchogram is defined as a pattern of air-filled bronchi on a background of airless lung. In pulmonary consolidations and infiltrates, air bronchograms are most commonly caused by pneumonia or pulmonary edema (especially with alveolar edema). Other potential causes of consolidations or infiltrates with air bronchograms are: For lung nodules, air bronchograms used to be associated with infectious causes of consolidation and, therefore to be benign. However, in the setting of a lung nodule, an air bronchogram is actually more frequent in malignant than in benign nodules. Qiang et al. studied the tumour-bronchus relationship and described five types: