Automated Extraction of Lymph Nodes from 3-D Abdominal CT Images Using 3-D Minimum Directional Difference Filter. - Takayuki Kitasaka; Yukihiro Tsujimura; Yoshihiko Nakamura; Kensaku Mori; Yasuhito Suenaga; Masaaki Ito; Shigeru Nawano (MICCAI (2), 2007)