Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy lingular opacity , best seen on the frontal view , pneumonia versus atelectasis . No pleural effusion or pneumothorax is seen . The cardiac right is top - normal . Mediastinal contours are grossly unremarkable . No pulmonary edema is seen .
    OUTPUT:
    
Patchy lingular opacity , pneumonia versus and / or atelectasis . No priors for comparison .