[1] Univ Hosp Leuven, Dept Radiol, B-3000 Louvain, Belgium
[2] AZ St Lucas, Dept Radiol, B-9000 Ghent, Belgium
[3] Univ Hosp Leuven, Dept Otorhinolaryngol Head & Neck Surg, B-3000 Louvain, Belgium
[4] Univ Hosp Leuven, Dept Pathol, B-3000 Louvain, Belgium