1Depts. Radiology and Clinical Research, University of Bern, Bern, Switzerland, 2Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Universitat Autònoma de Barcelona, Barcelona, Spain, 3DRNN, Institute of Diagnostic and Interventional Neuroradiology/SCAN, University Hospital Bern, Bern, Switzerland, 4CRUK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom