The Virtual Navigator (VN) technology was used for the fusion of transcranial Ultrasound (US) and brain Magnetic Resonance Images (MRI), with a repeatability error under 0.1 cm. The superimposition of US to the previously acquired MRI volume consisted of external point-based registration, that was subsequently refined with image-based registration of internal brain structures. The common registration procedure with the usage of external fiducial markers acquired with the two modalities was improved using facial anatomical landmarks, with a reduction of the internal targeted structure residual shift (maximum 0.7 cm in the cranio-caudal direction). This allowed the investigation of Deep Cerebral Veins and dural sinuses insonated from the condyloid process of the mandible, a recently introduced US window. The fusion of these vessels to the MRI volume provided their anatomical position and helped excluding false Doppler signal sources.