Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left mild - to - moderate pleural effusion has increased since ___ . Left lung base opacity could be related to atelectasis , aspiration or pneumonia in appropriate clinical setting . Mild pulmonary edema has completely resolved . Mediastinal and cardiac contour are normal . There is no pneumothorax .
    OUTPUT:
    
Left pleural effusion has worsened and is now mild - to - moderate . Left lower lung opacity could be compatible with atelectasis and / or infection in appropriate clinical setting .