[1] Johns Hopkins Univ Hosp, Dept Radiol, Div Neuroradiol, 600 N Wolfe St Phipps B100F, Baltimore, MD 21287 USA
[2] Hosp Geral Fortaleza, Dept Radiol, 900 Avila Goulart St, BR-60175295 Fortaleza, Ceara, Brazil
[3] Hosp Geral Fortaleza, Dept Neurosurg, 900 Avila Goulart St, BR-60175295 Fortaleza, Ceara, Brazil
[4] Hosp Univ Walter Cantidio, Dept Pathol, 1290 Pastor Samuel Munguba St, BR-60430372 Fortaleza, Ceara, Brazil