Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are unchanged , with the heart size appearing top normal . The pulmonary vascularity is normal . Linear opacities within both lung bases are compatible with subsegmental atelectasis . No focal consolidation , pleural effusion or pneumothorax is identified . No acute osseous abnormality is seen .
    OUTPUT:
    
Subsegmental atelectasis in both lung bases .