[1] Ernst Moritz Arndt Univ Greifswald, Inst Diagnost Radiol & Neuroradiol, Greifswald, Germany
[2] Alfried Krupp Hosp, Neurol Klin, Essen, Germany
[3] Klinikum Stuttgart, Neurochirurg Klin, Neurozentrum, Stuttgart, Germany
[4] Klinikum Stuttgart, Neurol Klin, Neurozentrum, Stuttgart, Germany
[5] Alfried Krupp Hosp, Klin Radiol & Neuroradiol, Essen, Germany
[6] Klinikum Stuttgart, Klin Neuroradiol, Neurozentrum, Stuttgart, Germany
[7] Ernst Moritz Arndt Univ Greifswald KOR, Univ Med Greifswald, Inst Diagnost Radiol & Neuroradiol, D-17487 Greifswald, Germany