Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left - sided pigtail catheter terminates just below the level of the aortic knob . The endotracheal tube is covered by the enteric tube and its tip can not be assessed . Remaining lines and monitoring devices are in unchanged position . As compared to prior chest radiograph from ___ , there has been significant improvement of the left - sided pleural effusion with a small amount of pleural fluid still remaining . Increased opacity at right lung base may represent atelectasis or overlying vascular structures . There is no definite pneumothorax .
    OUTPUT:
    
Interval placement of left pigtail catheter with significant improvement of left - sided pleural effusion .