Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . The lungs are hyperinflated with flattened diaphragms suggesting emphysema . No convincing evidence for pneumonia . No large effusion or pneumothorax . No signs of congestion or edema . Cardiomediastinal silhouette is stable . Atherosclerotic calcification of the aortic knob noted . Mediastinal contour is normal . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
No acute findings . No signs of pneumonia . Background emphysema .