Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Retrocardiac opacity and small - to - moderate bilateral pleural effusions are similar to the prior study three days ago . Cardiomegaly is unchanged . Two pacing leads from a left chest generator terminate in appropriate positions , overlying the right atrium and right ventricle . The generator of a stimulator device is seen in the left upper quadrant of the abdomen .
    OUTPUT:
    
Small to moderate bilateral pleural effusions and retrocardiac opacity are similar to ___ .