Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The previously seen mild interstitial edema has improved from prior exam . There is a persistent retrocardiac consolidative opacity , which may represent infection , aspiration , or atelectasis . Mild cardiomegaly and tortuous aorta are unchanged from prior exam . No significant pleural effusion is seen . There is no pneumothorax . Visualized osseous structures are unremarkable .
    OUTPUT:
    
1 . Improved mild pulmonary edema . 2 . Persistent retrocardiac consolidative opacity , which may represent infection , aspiration , or atelectasis .