Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable frontal view of the chest . The lungs are hyperexpanded , consistent with known COPD . There may be trace bilateral pleural effusions . A subtle parenchymal opacity is seen at the right lung base . The size of the cardiac silhouette is unchanged . A right internal jugular catheter has been removed in the interim .
    OUTPUT:
    
Subtle parenchymal opacity at the right lung base , may reflect sequela from prior infection , although , acute pneumonia should be considered .