Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild to moderate enlargement of cardiac silhouette is unchanged . The mediastinal and hilar contours are within normal limits . There is crowding of the bronchovascular structures . Retrocardiac streaky opacity may reflect atelectasis but infection is not excluded . No large pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities . Multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Low lung volumes with retrocardiac patchy opacity possibly reflective of atelectasis . Infection is not excluded in the correct clinical setting .