Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is moderately enlarged . Mediastinal and hilar contours are stable . There is no pulmonary edema . Patchy opacity within the left lower lobe could reflect atelectasis though infection is not completely excluded . No pleural effusion or pneumothorax is demonstrated . There are multilevel degenerative changes in the thoracic spine .
    OUTPUT:
    
Patchy opacity in the left lower lobe could reflect an area of atelectasis . Infection is not completely excluded in the correct clinical setting .