Virtual navigator registration procedure for transcranial application

The interest in fusion imaging technology for transcranial application, that is the registration of Echo-color Doppler Ultrasound (ECD) and a second 3D imaging modality, e.g. Magnetic Resonance Imaging (MRI) or Computed Tomography (CT), has recently grown thanks to studies of both arterial system and venous system. In addition the definition of a new ultrasound (US) cranial windows for the brain morphology and hemodynamic has given further attention to the topic. The present work analyses the registration procedure between US and a 3D imaging modality for transcranial application (CT for in vitro tests and MRI for in vivo applications). In vitro and in vivo fusion imaging sessions are tested comparing different choices of reference points. In vivo examples describing practical use of the Virtual Navigator are also presented. In conclusion, fusion of transcranial ECD to anatomical reference images is a robust tool for developing and validating new protocols and for training in clinical practice.