Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a dual - lead pacemaker / ICD device with leads again terminating in the right atrium and ventricle , respectively . The cardiac , mediastinal and hilar contours appear stable . A widespread interstitial abnormality has resolved . However , there is an increase in retrocardiac opacification in the left lower lobe . Particularly given the lack of generalized evidence for pulmonary edema and the focal nature of the opacity , pneumonia seems a likely etiology . The bones appear demineralized .
    OUTPUT:
    
Findings concerning for pneumonia in the left lower lobe .