1. Department of Neurological Surgery, UCSF, San Francisco, CA, USA
2. Department of Neurological Surgery, SFVAMC, San Francisco, CA, USA
3. Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
4. Department of Anatomy, Medical School Hamburg, University of Applied Sciences and Medical University, Hamburg, Germany
5. Department of Bioengineering, University of Washington, Seattle, WA, USA
6. Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA