Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours appear unchanged including moderate cardiomegaly . What is new is bilateral opacification of each lung base , which is especially confluent in the retrocardiac region on the left . Particularly on the right , small coinciding pleural effusion is suspected . Indistinct pulmonary vasculature appears mildly distended suggesting coinciding vascular congestion .
    OUTPUT:
    
Substantial opacities at both lung bases , raising concern for pneumonia . Findings also suggest mild coinciding vascular congestion and possibly small pleural effusions .