Nils Daniel Forkert Dennis Säring Till Illies Jens Fiehler Jan Ehrhardt Heinz Handels Alexander Schmidt-Richberg Direction-dependent level set segmentation of cerebrovascular structures. 79623S 2011 Image Processing https://doi.org/10.1117/12.877942 conf/miip/2011 db/conf/miip/miip2011.html#ForkertSIFEHS11