Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate fully expanded and clear lungs . Heart is stably mildly enlarged . Mediastinal and hilar contours are normal . There is no pleural effusion or pneumothorax . There is no intraperitoneal free air . A lucent retrocardiac structure represents a small hiatal hernia .
    OUTPUT:
    
Small hiatal hernia . Otherwise , normal chest radiograph .