Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Midline sternotomy wires mediastinal clips again noted . Mild cardiomegaly unchanged with a retrocardiac opacity concerning for pneumonia in the left lower lobe . The right lung appears largely clear . No large effusion or pneumothorax is seen . Mediastinal and hilar configuration is unchanged and normal . Bony structures are intact .
    OUTPUT:
    
Left lower lobe opacity concerning for pneumonia . Stable mild cardiomegaly .