Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left sided dual - chamber pacemaker is noted with leads terminating in the right atrium and right ventricle , unchanged . The heart size is normal . The mediastinal and hilar contours are unchanged with mild tortuosity of the thoracic aorta noted . The pulmonary vascularity is normal . No focal consolidation , definite pleural effusion or pneumothorax is noted . Mild interstitial opacity is re - demonstrated within the right lung base particularly laterally , which could reflect a chronic process . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
No evidence for pneumonia . Mild interstitial abnormality within the right lung base may reflect chronic changes .