[1] Univ Hosp Wurzburg, Dept Diagnost & Intervent Radiol, Wurzburg, Germany
[2] Univ Freiburg, Med Ctr Univ Freiburg, Fac Med, Dept Radiol,Med Phys, Freiburg, Germany
[3] Siemens Healthcare GmbH, Erlangen, Germany
[4] Univ Freiburg, Med Ctr Univ Freiburg, Fac Med, Dept Neuroradiol,Med Phys, Freiburg, Germany
[5] Univ Wurzburg, Dept Expt Phys Biophys 5, Wurzburg, Germany