Figure 1: Chest radiograph shows loss of right lung volume, abnormal opacity in the right lower lung obscuring the right hemidiaphragm, inferior displacement of the major fissure (arrows) and right hilum.
Figure 2: Coronal CT image revealed a large right hilar mass (star) resulting in right lower lobe atelectasis.
- Lower lobe atelectasis occurs in posterior, inferior and medial direction because of the presence of pulmonary ligaments
- Medial/inferior shift of major fissure; minor fissure may not shift
- Obscuration of hemidiaphragm, paraspinal interface; right heart border still visible
- Vertical orientation of lower lobe bronchi
- Inferior and medial displacement of ipsilateral hilum
- Triangular opacity of atelectatic lobe, with apex toward the hilum and base toward the hemidiaphragm