Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta is tortuous . Mediastinal and hilar contours are otherwise unremarkable . Pulmonary vasculature is normal . Subsegmental atelectasis is demonstrated in both lung bases . No focal consolidation , pleural effusion or pneumothorax is seen . No acute osseous abnormalities identified .
    OUTPUT:
    
Bibasilar subsegmental atelectasis .