Fig. 5

 A-E pre-operative MR and venous sinus of the patient with type IV. The patient’s tumor was located in the posterior third of the superior sagittal sinus, and the tumor invaded the ipsilateral wall and top of the superior sagittal sinus, and MRV imaging showed significant narrowing of the venous sinus; F, G resection of the extra-sinus tumor portion; H, I opening of the venous sinus and compression with gelatin sponge + cotton tape to stop bleeding; J-M patch suture of the venous sinus; N-R complete resection of the tumor, and post-operative MRV indicated patency of the venous sinus