Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The small left pleural effusion appears to be slightly improved compared to the exam from ___ . There is a left - sided pacer with the leads in appropriate position . There is stable moderate cardiomegaly . The hilar and mediastinal contours are unremarkable . The aerated regions of the lungs are unremarkable except for mild bibasilar atelectasis . The left - sided Pleurx catheter tip appears to be in appropriate position .
    OUTPUT:
    
Interval improvement of the small left - sided pleural effusion compared to the study from ___ .