Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is mildly enlarged . The aorta is unfolded , and the mediastinal and hilar contours are unchanged . The pulmonary vascularity is not engorged . Streaky retrocardiac opacity could reflect atelectasis but infection is not excluded . No pleural effusion or pneumothorax is present . There are multilevel degenerative changes in the thoracic spine with osteophytic spurring .
    OUTPUT:
    
Low lung volumes with retrocardiac streaky opacity possibly reflecting atelectasis . Infection is not excluded .