Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable view of the chest demonstrates ET tube terminating 6 .6 cm above the carina . Nasogastric tube is seen coursing through the esophagus , its tip out of field of view . Left subclavian central venous catheter tip projects over cavoatrial junction . Diffuse bilateral rounded lucencies predominantly at the lung bases signify emphysema , better assessed on CT exam of ___ . There is no pleural effusion or pneumothorax . Hilar and mediastinal silhouettes are unchanged . Heart size is normal . Perihilar vascular congestion is noted . Upper lobe heterogeneous opacities , left greater than right , are unchanged , which may represent infection or asymmetric pulmonary edema . Retrocardia opacity is new since ___ .
    OUTPUT:
    
1 . Heterogeneous opacities in the upper lungs , left greater than right , not significantly changed since ___ exam . Retrocardiac opacity is new since prior . Above findings may represent asymmetric pulmonary edema or multifocal infection 2 . Moderate emphysema with basal predominance , compatible with patient 's given history of alpha - 1 antitrypsin deficiency .