An Automatic Virtual Patient Reconstruction from CT-Scans for Hepatic Surgical Planning

Problem / Background : In order to help hepatic surgical planning we per fected automatic 3D reconstruction of patients from conventional CT-scan, and interactive visualization and virtual resection tools. Tools and Methods : from a conventional abdominal CT-scan, we have developed several methods allowing the automatic 3D reconstruction of skin, bones, kidneys, lung, liver, hepatic lesions, and vessels. These me thods are based on deformable modeling or thresholding algorithms followed by the application of mathematical morphological operators. From these anatomical and pathological models, we have developed a new framework for translating anatomical knowledge into geometrical and topological constraints. More precisely, our a pproach allows to automatically delineate the hepatic and portal veins but also to label the portal vein and finally to build an anatomical segmentation of the liver based on Couinaud definition which is currently used by surgeons all over the world. Fina lly, we have developed a user friendly interface for the 3D visualization of anat omical and pathological structures, the accurate evaluation of volumes and distances an d for the virtual hepatic resection along a user-defined cutting plane. Results : A validation study on a 30 patients database give s 2 mm of precision for liver delineation and less than 1 mm for all other anatomical and pathological structures delineation. An in vivo validation perfo rmed during surgery also showed that anatomical segmentation is more precise than t he delineation performed by a surgeon based on external landmarks. This surgery p lanning system has been routinely used by our medical partner, and this has resulted in an improvement of the planning and performance of hepatic surgery procedures. Conclusion : we have developed new tools for hepatic surgical planning allowing a better surgery through an automatic delineation and visualization of anatomical and pathological structures. These tools represent a fi rst step towards the development of an augmented reality system combined with computer assisted tele-robotical surgery.