Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are mildly decreased , compared to prior which accentuates the heart size and interstitial opacities . Nearly confluent opacities in the right upper lobe , are probably due to pneumonia . Heart size is mildly enlarged . There is no evidence for pneumothorax . Sternotomy wires and prosthetic aortic valve are again seen , unchanged . The aortic knob calcification is also unchanged . There is stable appearance of a well marginated soft tissue density in the anterior mediastinum , likely post op changes .
    OUTPUT:
    
Right upper lobe pneumonia .