Fig. 3From: Comparative evaluation of posterior percutaneous endoscopy cervical discectomy using a 3.7 mm endoscope and a 6.9 mm endoscope for cervical disc herniation: a retrospective comparative cohort studyPre- and postoperative C6-C7 MRI in axial view. a Red arrow demonstrates C6-C7 cervical disc herniation; b Green arrow indicates that C7 nerve root compression was removedBack to article page