Affiliation: | 1. Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., Campus Box 8131, Saint Louis, MO 63110;2. Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue, M-391, San Francisco, CA 94143;3. Departments of Pediatrics and Neurology, University of California, San Francisco, 400 Parnassus Avenue, San Francisco, CA 94143 |