Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a retrocardiac opacity obscuring the left hemidiaphragmatic contour . Prominence of the right hilum is similar in ___ . There is no pneumothorax . Pulmonary vascularity is normal .
    OUTPUT:
    
Dense retrocardiac opacity may represent a pleural effusion with atelectasis or consolidation secondary to pneumonia . Consider obtaining a lateral radiograph for better characterization .