Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Increasing linear opacity in the left lung base may reflect atelectasis , however developing pneumonia is possible . There is small left pleural effusion . Mildly enlarged cardiac silhouette is unchanged . Lungs are hyperinflated .
    OUTPUT:
    
Increasing linear opacity in the left lung base may reflect atelectasis , however developing pneumonia is possible .