Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is some atlectasis at the right base , but the lungs are otherwise clear . There is no evidence of pneumonia . The aorta is mildly tortuous but the heart is normal in size . The hilar contours are normal . The pleural surfaces are clear without effusion or pneumothorax .
    OUTPUT:
    
No evidence of pneumonia .