Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP view of the chest provided . Bibasilar opacities are likely due to layering effusions . The upper lung fields appear normal . A rounded retrocardiac opacity is seen , which is suspicious for hiatal hernia . The cardiomediastinal silhouette is enlarged , likely accentuated by technique . Degenerative changes are seen within the left shoulder . An endotracheal tube is seen terminating 3 .2 cm above the carina . A dual pacing device is seen within the left chest wall .
    OUTPUT:
    
1 . The endotracheal tube is appropriately positioned . 2 . Bibasilar opacities are seen in the lower lung fields , likely layering effusions . Probable moderate hiatal hernia .