Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . The lungs appear clear . A large retrocardiac opacities compatible with a known hiatal hernia . No overt signs of pneumonia or CHF . No pneumothorax or large effusion . Cardiomediastinal silhouette is stable . No displaced rib fracture noted . Degenerative changes of bilateral shoulders again noted .
    OUTPUT:
    
No acute intrathoracic process