Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is persistent complete opacification of right hemithorax with right mediastinal shift , consistent with right lung collapse . Shift of left heart border is less . Left lung is clear without pleural effusion . Right subclavian venous catheter terminates in mid SVC .
    OUTPUT:
    
Persistent right lung collapse , possibly secondary to mucous plugging .