Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Linear opacities in the lung bases are compatible with areas of subsegmental atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . No acute osseous abnormalities are identified . There is no subdiaphragmatic free air .
    OUTPUT:
    
Bibasilar subsegmental atelectasis . No subdiaphragmatic free air .