1. A method for creating a virtual model of an anatomical structure from a three-dimensional image volume, comprising: providing a three-dimensional image volume created from a plurality of two-dimensional images; setting a threshold value, above which is indicative that an imaged voxel is not representing tissue; selecting a seed point voxel in said three-dimensional image volume as a starting point; performing a plurality of iterations, each iteration comprising: segmenting voxels, immediately adjacent said seed point in all desired directions, that meet or exceed said threshold value; determining a number of voxels segmented in this iteration; if said number of voxels is greater than zero, determining whether said number is large enough to indicate leakage; removing leaked voxels and storing them as leaked objects for post-processing identifying segmented voxels as seed points for next iteration if no leakage is indicated; detecting when said number of voxels segmented equals zero; performing secondary iterations on leaked objects, if any, until said number of voxels segmented equals zero, said secondary iterations comprising: selecting voxels in a first iteration detecting leakage for a given leaked object as seed points; reducing said threshold value; segmenting voxels, immediately adjacent said seed points in all desired directions, that meet or exceed said threshold value; determining a number of voxels segmented in this iteration; if said number of voxels is greater than zero, determining whether said number is large enough to indicate leakage; removing leaked voxels and storing them as leaked objects for post-processing identifying segmented voxels as seed points for next iteration if no leakage is indicated.