Right Lower Lobe Atelectasis

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.

Imaging Findings

• 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

Our case: Right hilar mass causing obstructive right lower lobe atelectasis (squamous cell carcinoma)

Reference:

Parker MS, Rosado de Christenson ML, Abbott GF. Teaching atlas of chest imaging, 2006.

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