Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable semi-upright chest radiograph demonstrates rounded opacification projecting in right mid lung consistent with known mass . Interval decrease in right lower lung opacification is likely due to decreased effusion with residula right lower lung opacification concerning for pneumonia . No pleural effusion or pneumothorax identified . Stable mild enlargement of the cardiac silhouette corresponding with a moderate pleural effusion previously identified .
    OUTPUT:
    
No pneumothorax . Slightly improved aeration of the right lower lung . Finding likely represents residual pneumonia after interval decrease in right pleural effusion .