Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is enlarged . Patient is status post sternotomy for ascending aortic repair . There is tortuosity of the descending aorta . Increased focal density in the right lung base could reflect atelectasis , however a superimposed infectious process can not be excluded . The left lung is clear . There is no pneumothorax .
    OUTPUT:
    
Focal density in the right lung base could reflect atelectasis , however a superimposed infectious process can not be excluded .