1. School of Medicine, University of California, San Francisco, San Francisco, California
2. Department of Radiology, University of California, San Francisco, San Francisco, California
3. Department of Neurosurgery, University of Southern California, Los Angeles, California
4. Department of Biostatistics, University of California, San Francisco, San Francisco, California
5. Department of Neurosurgery, University of California, San Francisco, San Francisco, California