Fig. 3From: Application of unilateral biportal endoscopy technique to resect a thoracic spinal intradural extramedullary meningioma: technical report and review of the literatureBased on the results of preoperative imaging examination, intraoperative fluoroscopy is used to determine the tumor location, view portal, work portal (A–C), and the upper and lower boundaries of the tumor (D, E)Back to article page