Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable frontal chest radiograph was obtained . A left - sided chest tube has been inserted into the left lateral 6th rib interspace . The pigtail is not coiled . The left pneumothorax remains large . Rightward mediastinal shift is unchanged . Small pneumomediastinum is stable .
    OUTPUT:
    
Stable size of large left pneumothorax despite chest tube placement . A subsequently obtained chest radiograph demonstrates resolution of the pneumothorax .