Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is again status post coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours appear stable . What is new , however , is a new mild interstitial abnormality primarily affecting the right lower lobe with a very small pleural effusion on the right as well as thickened fissures . Particularly since other portions of the lungs appear essentially clear , an infectious process is favored based on the imaging , although atypical pulmonary edema is difficult to exclude .
    OUTPUT:
    
New right lower lobe opacity concerning for pneumonia . Vascular congestion seems less likely based on the imaging appearance , but correlation with clinical presentation is recommended .