Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are low in volume and show a confluent opacity in the left lower lobe . The cardiac silhouette is enlarged . The mediastinal silhouette is unremarkable . There is mild interstitial opacities bilaterally which could be related to low lung volumes . A left - sided pacer terminates with its leads in the right atrium and right ventricle , unchanged . Sternal wires are intact .
    OUTPUT:
    
Possible left lower lobe opacity could represent an early pneumonia . Mild interstitial edema .