1 Radiology Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Estadual do Cérebro Paulo Niemeyer, Rio de Janeiro, Brazil. Electronic address: sergio_faj@hotmail.com.
2 Radiology Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Estadual do Cérebro Paulo Niemeyer, Rio de Janeiro, Brazil.
3 Radiology Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Radiology Department, Federal Fluminense University, Rio de Janeiro, Brazil.