[1] Paracelsus Med Univ, Dept Neurosurg, Nurnberg, Bavaria, Germany
[2] Klinikum Nuremberg, Inst Radiol & Neuroradiol, Nurnberg, Bavaria, Germany
[3] Univ Erlangen Nurnberg, Dept Anat 2, Univ Str 19, Erlangen, Bavaria, Germany
[4] Heidelberg Univ, Dept Neurosurg, Heidelberg, Baden Wuerttemb, Germany