1. Department of Radiology; Medimagem - Hospital da Beneficência Portuguesa; São Paulo Brazil
2. Department of Radiology; Santa Casa de Misericordia of Sao Paulo; Brazil
3. Department of Radiology; University of Washington; Seattle WA
4. Department of Radiology; University of Alabama at Birmingham; Birmingham AL
5. Department of Neurology; University of Tennessee Health Sciences Center; Memphis TN
6. Department of Radiology; Rush University; Chicago IL