Background Recent studies have shown the challenges involved in detecting small conflicting vessels (1.0-1.5 mm) on contrast-enhanced (CE) T1 images during stereoelectroencephalography (SEEG) planning. Improving the resolution of non-invasive approaches to identify these vessels is possible and important. We present a superior sagittal sinus mapping-based CE-magnetic resonance venography (CE-MRV) protocol calibrated by craniotomies. Method Seven patients with epileptic symptoms who received craniotomy were enrolled. CE-MRV was acquired with a bolus mapping of the superior sagittal sinus. Together with the T1 image, 3D veins and the brain surface were visualized. The resolution of the CE-MRV was quantified by measuring the diameter of superficial drainages after exposure of the brain surface during craniotomy. Results A total of 37 superficial drainages were exposed in the bone windows. CE-MRV visualized all these drainages. On average, one superficial drainage could be found in every 13.2 mm diameter of the bone window. The boundary resolution of the CE-MRV was 0.58-0.8 mm in vessel diameter, while drainages larger than 0.8 mm were visualized consistently. Conclusions The resolution of the CE-MRV in the present study met the requirement for detection of small conflicting vessels during SEEG planning. The visualized venous landmarks could be used for visual guidance to the surgical zone. As a non-invasive approach, CE-MRV is practical to use in the clinical setting.