Abstract : Micro-tomography produces high resolution images of bio- logical structures such as vascular networks. In this paper, we present a new approach for segmenting vascular network into pathological and normal regions from considering their micro-vessel 3D structure only. We consider a partition of the volume obtained by a watershed algorithm based on the dis- tance from the nearest vessel. Each territory is characterized by its volume and the local vascular density. The volume and density maps are first regularized by minimizing the total vari- ation. Then, a new approach is proposed to segment the vol- ume from the two previous restored images based on hypoth- esis testing. Results are presented on 3D micro-tomographic images of the brain micro-vascular network.