Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear . There is mild left lower lobe atelectasis . The hila and pulmonary vasculature are normal . No pleural abnormalities or pneumothorax . The cardiomediastinal silhouette is normal and unchanged . No fractures .
    OUTPUT:
    
No pneumonia . Small left lower lobe atelectasis .