Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: New left lower lobe and retrocardiac opacity can be aspiration pneumonia in the appropriate clinical setting . No pulmonary edema . Probable small left effusion , although difficult to assess on this single view . Heart size is normal . No pneumothorax .
    OUTPUT:
    
New left lower lobe consolidation can be atelectasis or pneumonia due to aspiration .