Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are within normal limits and unchanged . The heart is normal in size . There is a small to moderate left pleural effusion , which has increased since the prior examination . Opacity at the left base most likely represent adjacent atelectasis however superimposed infection can not be excluded . Also seen is opacification of the left upper lobe , which has improved since the prior study . A subtle opacity in the right mid lung is concerning for an additional focus of pneumonia . A small right pleural effusion is stable .
    OUTPUT:
    
1 . Small to moderate left pleural effusion , new from the prior exam with adjacent left lower lobe opacity which may represent adjacent atelectasis or superimposed infection . 2 . Left upper lobe opacities are improved from the prior study . 3 . Opacity in the right midlung is concerning for an additional focus of pneumonia .