1. The Department of Neurology, Oregon Health Sciences University, Portland, Oregon
2. Division of Neurosurgery, Oregon Health Sciences University, Portland, Oregon
3. Departments of Medicine, Oregon Health Sciences University, Portland, Oregon
4. Diagnostic Radiology, Oregon Health Sciences University, Portland, Oregon
5. Department of Mathematical Sciences, Portland State University, Portland, Oregon
6. Portland and Providence Medical Center Comprehensive Cancer Center, Portland, Oregon