Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Nasogastric tube terminates in the midline of the abdomen . Right upper extremity PICC line terminates at the superior cavoatrial junction . Prosthetic aortic valve is noted . Lung volumes are low with a heterogeneous opacification in the infrahilar region bilaterally , likely representing atelectasis . Diffuse retrocardiac opacification is indicative of left lower lobe collapse . This could be obscuring an underlying pneumonia . There is mild upper zone redistribution and central pulmonary vascular prominence . No pneumothorax . Small left effusion is hard to exclude . There is significant dextro convex scoliosis of thoracic spine .
    OUTPUT:
    
1 . Low lung volumes with left lower lobe collapse , unchanged from ___ . 2 . Right infrahilar opacification likely represents atelectasis . 3 . Mild pulmonary edema .