Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild unfolding and calcification of the thoracic aorta . The heart is normal in size . In addition to coarse lung markings of uncertain chronicity , there is a patchy retrocardiac opacity . There is no definite pleural effusion or pneumothorax .
    OUTPUT:
    
Retrocardiac opacity , possibly atelectasis but not specific . Short - term follow - up radiographs are suggested if pneumonia or aspiration is a clinical concern .