Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left chest wall pacer and multiple leads are in stable , expected position . The heart is enlarged , but stable in size from the prior examination . The aorta is tortuous and shows mural calcification . A new retrocardiac opacity is identified and is suggestive of atelectasis however infection should be considered . There is no pulmonary vascular engorgement or pulmonary edema . The right lung appears clear . There are no large pleural effusions or pneumothorax identified .
    OUTPUT:
    
Retrocardiac opacity suggests atelectasis however infection should be considered in the appropriate setting . No edema .