Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Semi-upright portable radiograph of the chest demonstrates increased hazy opacification of the right lung which may represent a layering pleural effusion and has increased since the prior study from ___ . Additionally , a left retrocardiac opacity is present , which may represent atelectasis versus pneumonia . Increased prominence of central pulmonary vasculature may be positional in nature . No overt pulmonary edema is present .
    OUTPUT:
    
1 . Increased right pleural effusion . 2 . Retrocardiac opacification may be due to atelectasis , however , underlying pneumonia can not be excluded .