Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . Left - sided pacemaker device is noted with leads terminating in the right atrium and right ventricle . Heart is moderately enlarged but unchanged . The aorta is diffusely calcified and tortuous . Pulmonary vascularity is not engorged . The lungs remain hyperinflated with flattening of the diaphragms suggestive of underlying chronic obstructive pulmonary disease . There are interstitial changes within the lung bases , with no new focal opacity demonstrated . Additionally there is a suggestion of punctate high density material within the right lung base . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Chronic interstitial abnormality within the lung bases which could reflect chronic aspiration given the presence of punctate radiopaque material in the right lung base possibly representing aspirated barium . Findings could be better characterized with a dedicated chest CT on a nonemergent basis .