An image registration system, comprising: an endoscope operable for generating an intra-operative endoscopic image of a vessel tree within an anatomical region, wherein the intra-operative endoscopic image of the vessel tree includes a plurality of branches of the vessel tree visible within the intra-operative endoscopic image as an indication of a furcation of the vessel tree invisible within the intra-operative endoscopic image; and an endoscope controller operable for image registering the intra-operative endoscopic image of the vessel tree to a pre-operative three-dimensional image of the vessel tree within the anatomical region, wherein the image registration includes: delineating a polygonal area on the intra-operative endoscopic image enclosing the furcation of the vessel tree invisible within the intra-operative endoscopic image, including: marking each branch of the vessel tree visible within the intra-operative endoscopic image as a branch segment; extending rays from each branch segment; and delineating overlapping rays of different branch segments; and defining a furcation candidate within the polygonal area as a detection of the furcation of the vessel tree invisible within the intra-operative endoscopic image; and wherein the image registration includes an image matching of a graphical representation of the furcation of the vessel tree as indicated by the visible branches of the vessel tree within the intra-operative endoscopic image of the vessel tree to a graphical representation of the furcation of the vessel tree within the pre-operative three-dimensional image of the vessel tree. an endoscope operable for generating an intra-operative endoscopic image of a vessel tree within an anatomical region, wherein the intra-operative endoscopic image of the vessel tree includes a plurality of branches of the vessel tree visible within the intra-operative endoscopic image as an indication of a furcation of the vessel tree invisible within the intra-operative endoscopic image; and wherein the intra-operative endoscopic image of the vessel tree includes a plurality of branches of the vessel tree visible within the intra-operative endoscopic image as an indication of a furcation of the vessel tree invisible within the intra-operative endoscopic image; and an endoscope controller operable for image registering the intra-operative endoscopic image of the vessel tree to a pre-operative three-dimensional image of the vessel tree within the anatomical region, wherein the image registration includes: delineating a polygonal area on the intra-operative endoscopic image enclosing the furcation of the vessel tree invisible within the intra-operative endoscopic image, including: marking each branch of the vessel tree visible within the intra-operative endoscopic image as a branch segment; extending rays from each branch segment; and delineating overlapping rays of different branch segments; and defining a furcation candidate within the polygonal area as a detection of the furcation of the vessel tree invisible within the intra-operative endoscopic image; and delineating a polygonal area on the intra-operative endoscopic image enclosing the furcation of the vessel tree invisible within the intra-operative endoscopic image, including: marking each branch of the vessel tree visible within the intra-operative endoscopic image as a branch segment; extending rays from each branch segment; and delineating overlapping rays of different branch segments; and marking each branch of the vessel tree visible within the intra-operative endoscopic image as a branch segment; extending rays from each branch segment; and delineating overlapping rays of different branch segments; and defining a furcation candidate within the polygonal area as a detection of the furcation of the vessel tree invisible within the intra-operative endoscopic image; and wherein the image registration includes an image matching of a graphical representation of the furcation of the vessel tree as indicated by the visible branches of the vessel tree within the intra-operative endoscopic image of the vessel tree to a graphical representation of the furcation of the vessel tree within the pre-operative three-dimensional image of the vessel tree.