aDepartment of Radiology and Biomedical Imaging, University of California, San Francisco, California 94107, USA

bDepartment of Diagnostic and Interventional Radiology, University Medical Center Freiburg, Freiburg im Breisgau

cDepartment of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany

Correspondence to Maximilian T. Löffler, Department of Radiology and Biomedical Imaging, University of California, 185 Berry St, Suite 350, San Francisco, CA 94107, USA. Tel: +1 415 514 9655; e-mail: [email protected]