Preoperative evaluation of venous systems with magnetic resonance venography in parasagittal meningiomas

الملخص EN

Background : Parasagittal meningiomas may pose a difficult surgical challenge because venous patency and collateral anastomoses have to be clearly defined for correct surgical planning.

Aim: The aim of this case series was to study the diagnostic accuracy of magnetic resonance venogra-phy (MRV) in assessing the superior sagittal sinus (SSS) obstruction and venous collaterals in pa-tients with parasagittal meningioma.

Patients and Methods: Seven patients from 2010 through 2012 undergoing surgery for meningiomas located adjacent to the SSS were prospectively evalu-ated.

All patients underwent both conventional magnetic resonance imaging and MRV.

Magnetic resonance venography was evaluated to assess: (1) patency of the sinus (Permeable / Occluded), (2) the extent of occlusion (in centimeters), and (3) the number of collateral anastomoses close to the insertion of the meningioma.

Magnetic resonance venography assessment was compared with surgery.

All patients were operated on, and the intraoperative findings were taken as the reference standard.

Results: Magnetic resonance venography showed the sinus to be occluded in 3 cases.

MRV data were confirmed by surgery, showing 3 patients to have an occlusion of the SSS.

The MRV sensitivity was thus 100%.

Magnetic resonance venography recognized 90% of collateral venous anastomoses close to the meningioma as subsequently confirmed by surgery.

Conclusion: In the preoperative planning for patients with meningiomas located close to the SSS, MRV can provide additional and more reliable information concerning venous infiltration, patency of the SSS, and the presence of collateral anastomoses.