Fig. 4

Intradural extramedullary mass lesions. A Upper cervical meningioma (female patient, 40 years old, laminectomy); a preoperative T1MRI with contrast, b early postoperative T1 MRI, c follow-up T1 MRIwith contrast after 6 months, d intraoperative photo and e ultrasound images; arrow 1; compressed spinal cord, 2; the tumor and 3; the spinal cord after tumor resection. B Dorsal meningioma (male patient, 35 years old, laminectomy); a preoperative MRI, b early postoperative MRI, c follow-up T1 MRIwith contrast after 6 months, d intraoperative photo and e ultrasound images; arrows 1; the tumor, 2; the spinal cord