1. Department of Neurology Neurosurgery & Radiology, University of Iowa Hospitals and Clinics, Iowa City Iowa
2. Department of Neurosurgery Hospital Nacional Daniel Alcides Carrion Callao Peru
3. School of Medicine Universidad Mayor de San Marcos Lima Peru
4. Neuroscience, Clinical Effectiveness and Public Health Research Group Universidad Científica del Sur Lima Peru
5. Department of Neuroradiology Sanatorio Sagrado Corazon Buenos Aires Argentina
6. Department of Neuroradiology Instituto Oulton Cordoba Argentina
7. Department of Neurosurgery Montefiore Medical Center Bronx NY
8. Department of Radiology University of Massachusetts Medical School Worcester MA