Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are normally expanded without focal airspace opacity . There is mild bibasilar atelectasis . There is no pleural effusion or pneumothorax . The convexity of the ascending aortic arch , while similar to ___ , is notably more prominent since the next most recent study . The cardiac countour is normal in size .
    OUTPUT:
    
1 . Prominent ascending aortic convexity raises the possibility of acute aortic syndrome . 2 . Mild bibasilar atelectasis , but no evidence of pneumonia . Updated results telephoned to Dr . ___ by ___ at 8 : 30 am , ___ , 5 minutes after discovery .