Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Overall , there is little change in a loculated large left pleural effusion since ___ with associated rightward mediastinal shift . A left basilar pigtail catheter has been placed projecting over the left base . There is no evidence of pneumothorax . There is no large right effusion or pneumothorax , with a trace effusion not excluded . There is mild vascular congestion . There is dense left basilar consolidation , likely atelectasis , and effusion .
    OUTPUT:
    
Stable appearance of a loculated effusion after left basilar pigtail placement on the left . No evidence of pneumothorax . In comparison to prior Chest CT , the largest area of fluid is demonstrated superolaterally in relation to the pigtail catheter , with the catheter probably external to this region .