Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours appear unchanged . There is a persistent small to moderate right - sided pleural effusion with fissural component on the right , which is difficult to evaluate on the lateral view because the arms are down . However , although overall fluid content has probably decreased , coinciding parenchymal opacity has increased . Vague lingular opacity is unchanged .
    OUTPUT:
    
Persistent small to moderate right - sided pleural effusion with fissure ill component , probably with some decrease since remote prior study but with increased parenchymal opacity . The latter may be due to chronic round atelectasis although more acute superimposed atelectatic change or even infection is not excluded . Correlation with more recent prior radiography may be helpful if available . .