1. Department of Neurosurgery, Universidade Federal de São Paulo, Brazil
2. Department of Radiology, Hospital Beneficencia Portuguesa de São Paulo, Brazil
3. Department of Interventional Neuroradiology, Pontificia Universidade Católica de Campinas, Campinas, São Paulo, Brazil,
4. Department of Neurosurgery, Bolivian Neurosurgery Institute, Cochabamba, Bolivia.