Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Newly placed right pigtail chest tube drain projects over the right upper hemithorax . Large right pneumothorax has minimally decreased in size and there is no longer evidence of tension . The heart is top - normal in size . The mediastinum is not widened . No left pneumothorax . The aerated lungs are clear . No acute osseous abnormality .
    OUTPUT:
    
Following placement of right pigtail pleural catheter , a large right pneumothorax has minimally decreased in size . .