Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Comparison with prior study , there is no significant change . Midline sternotomy wires are present . Cardiac silhouette remains mildly enlarged in this patient with previously diagnosed pericardial effusion . No evidence of pleural effusion , pneumothorax , or pneumonia .
    OUTPUT:
    
Persistent mild cardiomegaly .