Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to the chest radiograph obtained 1 day prior , there has been interval improvement in opacification at the left lung base , though there remains a retrocardiac consolidation with faint air bronchograms , likely atelectasis , dependent edema , or pneumonia . Pleural effusions small , if any . Heart size top - normal with mild pulmonary edema .
    OUTPUT:
    
Persistent retrocardiac consolidation may be atelectasis , dependent edema , or pneumonia . New , mild pulmonary edema .