Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal with mild tortuosity of the thoracic aorta . There is mild central pulmonary vascular congestion without frank interstitial edema . Lungs are clear . Pleural surfaces are clear without effusion or pneumothorax . There is a rounded midline retrocardiac density unchanged from prior examination which could represent a small hiatal hernia .
    OUTPUT:
    
1 . Mild central pulmonary vascular congestion without frank edema . No consolidation to suggest pneumonia . 2 . Small rounded retrocardiac density which may represent a hiatal hernia , unchanged from prior study .