Step 1: Calculate the probability distribution of the cerebral vessels and other brain tissue (background), and automatically obtain seed region of cerebral vessels

Step 2: Reconstruct main cerebrovascular structure using the region distribution obtained in Step 1

Step 3: Initialize the approximate level set function with surface of the main cerebrovascular structure using Eq. 13

Step 4: Compute edge-function g(Ii,j,k), velocity function V(Ii,j,k), restriction variable αi,j,k, and curvature K for the grid points on zero level set

Step 5: Iterate level set function based on Eq. 14

Step 6: If the stopping condition Eq. 15 is satisfied, stop; otherwise, go to Step 4