Air bronchograms – CT

Air bronchograms. Air bronchograms are characteristic of consolidation, and are clearly evident on this CT image from a patient with right middle lobe pneumonia. They are often visible on CXR. This sign is produced by fluid-filled (and therefore opaque) alveoli and small airways contrasting with air-filled larger bronchi. The presence of air bronchograms is a reassuring sign as it helps exclude an obstructing lesion in a central airway.