Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable semi upright view of the chest . AICD is unchanged . Overlying EKG leads are present somewhat limiting assessment . Low lung volumes limits evaluation . Lower lung opacities are concerning for pneumonia versus atelectasis . The upper lungs appear well aerated . No pneumothorax or large effusion . Heart size can not be assessed . Mediastinal contour appears unchanged . Bony structures are intact .
    OUTPUT:
    
Limited exam with subtle lower lung opacities concerning for pneumonia versus atelectasis .