Figure 53-10 Horizontal (top) and coronal magnetic resonance images of a parasagittal meningioma.^[101] Resection of meningiomas arising from the dural reflection overlying the sagittal sinus or from the dura of the adjacent convexity or falx entails a risk of venous air embolism because of the proximity of the sagittal sinus (the triangular structure at the superior end of the interhemispheric fissure in the bottom panel).