1. Department of Neurosurgery, Hospital Felício Rocho e Hospital de Pronto-Socorro João XXIII , Belo Horizonte, MG, Brazil
2. Department of Neurosurgery, Universidade Federal de São Paulo, São Paulo, SP, Brazil
3. Department of Neurosurgery, Faculdade Ciências Médicas de Minas Gerais, Belo Horizonte, MG, Brazil
4. Department of Nuclear Engineering, Instituto Militar de Engenharia, Rio de Janeiro, RJ, Brazil