[1] Univ Mons, Fac Med, Dept Anat, B-7000 Mons, Belgium
[2] Univ Libre Bruxelles, Erasme Hosp, Dept Neurosurg, Brussels, Belgium
[3] Inst Pathol & Genet, Loverval, Belgium
[4] Univ Libre Bruxelles, CHU Charleroi, Dept Radiol, Brussels, Belgium
[5] Inst Pathol & Genet, B-6041 Gosselies, Belgium
[6] Univ Libre Bruxelles, CHU Charleroi, Dept Neurosurg, Brussels, Belgium