Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear without confluent consolidation . There is no pulmonary edema or pleural effusions . Mediastinal and hilar contours are within normal limits . The cardiac silhouette is mildly enlarged . There is no pneumothorax .
    OUTPUT:
    
Mild enlargement of the cardiac silhouette may be due to cardiomegaly and / or pericardial effusion .