Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The aorta shows mild tortuosity and calcification . The heart is normal in size allowing for technique . There is no definite pleural effusion or pneumothorax . The lungs appear clear . Vague retrocardiac opacity is most likely due to minor atelectasis .
    OUTPUT:
    
No convincing evidence for pneumonia . Vague retrocardiac density that can probably be explained by atelectasis .