Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy . Heart size is normal . Mediastinal and hilar contours are unchanged . The right internal jugular central venous catheter has been removed . The pulmonary vasculature is normal . Lung volumes remain low . Linear opacities in the lung bases are compatible with areas of subsegmental atelectasis . No focal consolidation , large pleural effusion or pneumothorax is present . No acute osseous abnormalities visualized .
    OUTPUT:
    
Bibasilar subsegmental atelectasis .