Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild enlargement of cardiac silhouette . The mediastinal contours are unchanged . There is mild pulmonary vascular engorgement and small bilateral pleural effusions which have decreased in size compared to the previous exam . Patchy bibasilar airspace opacities likely reflect atelectasis , but infection is not fully excluded . No pneumothorax is demonstrated . Multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Small bilateral pleural effusions , mild pulmonary vascular engorgement , and bibasilar atelectasis . Infection , however , within the lung bases can not be completely excluded .