Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Interval placement of a left - sided chest tube with the tip terminating at the left lung apex . A large left pleural effusion with significant compressive atelectasis has minimally decreased in size as compared to the prior examination . There is no appreciable mediastinal shift identified . The right lung is grossly clear .
    OUTPUT:
    
Status post placement of a left - sided chest tube with slight interval decrease in a large , loculated , left pleural effusion with significant compressive atelectasis .