1. Division of Neuroradiology, Department of Radiology, McGill University, Montreal, Quebec, Canada
2. Departamento de Neurorradiologia, Rede Mater Dei de Saúde, Belo Horizonte, Minas Gerais, Brazil
3. Clinica Radiologica Rio Verde CRRV, Rio Verde, Goiás, Brazil
4. Radiology Department, Universidade de Ribeirão Preto, Guarujá, São Paulo, Brazil