Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate mild to moderate cardiomegaly , similar compared to ___ . Retrocardiac / lingular opacity is concerning for pneumonia . There is also mild right base atelectasis . There is no appreciable pleural effusion or pneumothorax . The visualized upper abdomen is unremarkable .
    OUTPUT:
    
Retrocardiac / lingular opacity concerning for pneumonia .