Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is moderate cardiomegaly . The aortic knob is calcified . The right lung is clear . A retrocardiac opacity most likely represents atelectasis . There are linear lucencies in the left lower lobe , possibly representing bronchiectasis . No pleural effusion or pneumothorax .
    OUTPUT:
    
Moderate cardiomegaly . A retrocardiac opacity most likely represents atelectasis , but infection can not be excluded Linear lucencies in the left lower lobe most likely represent bronchiectasis .