Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were performed . The lung volumes are low . There is no definite pleural effusion . There is no pneumothorax . Retrocardiac opacities are likely from atelectasis . The cardiac silhouette is mildly enlarged , but unchanged . The hilar and mediastinal structures are stable .
    OUTPUT:
    
Retrocardiac opacities are likely atelectasis .