Abstract. Volume representations of blood vessels acquired by 3D rotational angiography are very suitable for diagnosing an aneurysm. We presented a fully-automatic aneurysm labelling method in a previous paper. In some cases, a portion of a "normal" vessel part connected to the aneurysm is incorrectly labelled as aneurysm. We developed a method to detect and correct these erroneous border areas. Application of this method gives better estimates for the aneurysm volumes.