Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single - view chest x-ray in upright position shows interval improvement of pulmonary edema , but new right lung base opacity due to atelectasis , probably in the right middle lobe . Left lung base opacity has improved , probably for reduced atelectasis . There is no pleural effusion or pneumothorax . Heart size is top normal . Stable aortosclerosis .
    OUTPUT:
    
Interval improvement of pulmonary edema with better ventilation of the left lung base , but new right lung base opacity compatible with right middle lobe atelectasis .