Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is background hyperinflation , with flattening of the diaphragms . Heart size is at the upper limits of normal . Aorta is minimally unfolded . Within the limits of plain film radiography , no hilar or mediastinal lymphadenopathy is detected . No CHF , focal infiltrate , effusion , or pneumothorax is detected . Mild degenerative changes of the thoracic spine are noted . No free air seen beneath the diaphragms .
    OUTPUT:
    
No acute pulmonary process identified .