Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with the immediate prior study of ___ , there may be a small to moderate left pleural effusion and increasing retrocardiac atelectasis . Otherwise , there is no change to the postoperative appearance of the mediastinum . There is no pulmonary edema or pneumothorax . A right IJ central venous catheter tip ends at the cavoatrial junction . There is stable mild cardiomegaly .
    OUTPUT:
    
1 . Possible small to moderate left pleural effusion with increasing retrocardiac atelectasis . 2 . Unchanged postoperative appearance of the mediastinum .