Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: This study is presented for dictation on ___ . The presence of a large pneumothorax was known at the time with radiographs proceeding and following this study on the same day . There is only minimal reexpansion of the completely collapsed left lung with a chest tube in place . Mediastinal shift has almost completely resolved although a large pneumothorax persists following chest tube placement . There is no focal consolidation or pleural effusion .
    OUTPUT:
    
Persistent large left - sided pneumothorax but with resolution of rightward mediastinal shift following insertion of chest tube .