Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are unchanged compared to the prior study . Previous median sternotomy and coronary artery bypass graft clips noted . Even allowing for the projection , the heart is moderately to severely enlarged . Haziness of pulmonary vasculature is consistent with congestive heart failure . The extent of airspace opacities slightly decreased when compared to the prior study consistent with slight interval improvement in the known pulmonary edema . No pleural effusion or pneumothorax seen .
    OUTPUT:
    
Possible slight interval improvement in the moderate pulmonary edema .