Functional MR imaging with venography for neurosurgical identification of the central sulcus

We evaluated the applicability of functional MR imaging overlaid onto brain images superimposed venography for neurosurgical identification of the central sulcus. In 20 volunteers and 12 patients with brain tumors located around the sensorimotor cortex, gradient echo and large flip angle functional MR image was performed to allow visualization of flow effect and susceptibility related changes in relative large vein by motor hand task. Functional MR image acquired was overlaid on 3D anatomical image with 3D venography. Based on the 3D mapping, intra-operative cortical somatosensory evoked potentials (SEPs) were recorded. The significant activation area obtained from functional MR imaging was projected on an ascending cortical vein in 16 volunteers (80%) and 10 patients (83%). Comparing the anatomical activation map with visual inspection of the exposed cortical surface made it easy to identify the activation area during surgery. The cortical veins in 9 of 10 were validated as a central vein by intra-operative cortical recording of SEPs. Combination of functional MR imaging overlaid onto 3D anatomical image with venography and intra-operative SEPs permitted rapid and accurate localization of the central sulcus during surgery.