Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Midline sternotomy wires again noted as well as metallic stent within the descending thoracic aorta . There is subtle opacity at the left lung base likely representing atelectasis with adjacent effusion though can not exclude pneumonia . The lungs are otherwise clear . The cardiomediastinal silhouette is stable . Bony structures are intact .
    OUTPUT:
    
Subtle opacity in the left lung base concerning for effusion with atelectasis / pneumonia . Extensive aortic graft in place .