Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Posterior right base opacity is seen , which may be due to atelectasis or pneumonia . No large pleural effusion is seen . There is no pneumothorax . The cardiac silhouette is top - normal . Mediastinal contours are unremarkable .
    OUTPUT:
    
Patchy posterior basilar opacity could be due to pneumonia