1. Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, California 94305, United States
2. Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94304, United States
3. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
4. Department of Surgical and Radiological Sciences, University of California at Davis, Davis, California 95616, United States
5. Department of Pathology, Microbiology and Immunology, University of California, Davis, California 95616, United States
6. Department of Bioengineering, Stanford University, Stanford, California 94305, United States
7. Stanford Neuroscience Institute, Stanford University School of Medicine, Stanford, California 94305, United States