An Improved Fuzzy Connectedness Method for Automatic Three-Dimensional Liver Vessel Segmentation in CT Images

Algorithm 1

Improved vesselness filter.

	Input: the liver VOI CT image IVOI.
	Output: the vesselness image Ivesselness.
(1)	Set the vessel scales , ; threshold .
(2)	Perform adaptive sigmoid filtering to IVOI by using Equations (3) and (4) to obtain the filtered image Isigmoid.
(3)	Perform isotropic resampling to Isigmoid.
(4)	For do
(5)	Compute the Hessian matrix elements at each coordinate ;
(6)	Make eigenvalue decomposition , ;
(7)	Rank , ;
(8)	Compensate by using Equation (1);
(9)	Perform vesselness filtering by using Equation (5);
(10)	until .
(11)	End for
(12)	Compute the vesselness image by using Equation (6).