Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is enlarged . There is patchy left basilar opacity suggesting minor atelectasis superimposed on a prominent pericardial fat pad , not significantly changed , although it is difficult to exclude a superimposed process . Elsewhere , the lungs appear clear . There is no definite pleural effusion , although again it is difficult to exclude a small pleural effusion on the left side . There is no pneumothorax .
    OUTPUT:
    
Patchy left basilar opacity , probably due to minor atelectasis and the cardiac fat pad , although it is difficult to exclude a small pleural effusion .