Axis extraction of three-dimensional blood vessel images is the first and most important step in quantifying blood vessel.A dynamic method of extracting axis of three-dimensional blood vessel images was proposed.Firstly

the energy constraint equations has been constructed

the initial skeleton curve of blood vessel images obtained by thinning algorithm or artificial constructing method keeps the approximation location of the axis of blood vessels under energy constraint equations and along the distance field gradient direction of blood vessel images.When the equation energy reaches a minimum value

the initial skeleton is also fixed in the axis position at this time.Experimental results show that the position of the blood vessels axis extracted by this method is accurate

and the axis preserves topology and connectivity.