Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild to moderate cardiomegaly is unchanged . The mediastinal and hilar contours are stable . Pulmonary vasculature is not engorged . Streaky left retrocardiac opacity likely reflects atelectasis . No pleural effusion or pneumothorax is demonstrated . Moderate multilevel degenerative changes in the thoracic spine are noted .
    OUTPUT:
    
Left basilar atelectasis . No evidence of pulmonary edema .