1. Stroke Diagnostics and Therapeutics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
2. Center for Neuroscience and Regenerative Medicine, Bethesda, Maryland.
3. Department of Radiology, University Medical Center Groningen, Groningen, The Netherlands.
4. Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, Maryland.
5. Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland.
6. Seton Dell Medical School Stroke Institute, University of Texas, Austin, Texas.