Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Slightly increased left lung base opacity is likely due to increased small to moderate pleural effusion and compressive atelectasis . Superimposed pneumonia is possible in correct clinical setting . Previously seen interstitial edema in the right lung is improved . Cardiac silhouette is obscured by the left lung base opacity .
    OUTPUT:
    
Slightly increased left lung base opacity could due to increased small to moderate pleural effusion and compressive atelectasis . Superimposed pneumonia is possible in correct clinical setting . Previously seen interstitial edema in the right lung is improved , further supporting possibility of pneumonia causing the left lung base consolidation , rather than fluid overload .