Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Re - demonstrated is severe thoracolumbar scoliosis . Retrocardiac opacity may reflect a combination of a layering pleural effusion and atelectasis . Minimal atelectasis at the right lung base . No pneumothorax identified . The appearance of the cardiomediastinal silhouette is unchanged .
    OUTPUT:
    
Retrocardiac opacity may reflect a combination of a layering pleural effusion and atelectasis .