HepaVision2 – A software assistant for preoperative planning in living-related liver transplantation and oncologic liver surgery H. Bourquain, A. Schenk, F. Link, B. Preim, G. Prause, H.-O. Peitgen MeVis – Center for Medical Diagnostic Systems and Visualization, Universitätsallee 29, 28359 Bremen, Germany, Email: bourquain@mevis.de Abstract HepaVision2, a user friendly software application for preoperative planning based on CT images in liver surgery is presented. It is intended for both, evaluation of potential donors in living-related liver transplantation and planning of oncologic resections. The planning takes into account the patient’s individual anatomy allowing for fully automatic calculation of individual resection proposals including volumetric analysis. The results are visualized in 3D, thus allowing the surgeon to choose the optimal strategy for each patient. The software was tested in over 50 cases by our clinical partners and our institution. Average time needed per case is below one hour, therefore allowing the use of the software application in clinical routine. Keywords: Living-related liver transplantation, oncologic resections, computer-assisted preoperative planning 1. Introduction Shortage of cadaveric organs for transplantations leads to an increase in living-related transplantations. For example the number of living-related liver transplantations (LRLT) in the United States of America grew from 86 in 1998 to 219 in 1999 [1]. As the donors are healthy volunteers their eligibility to donate a portion of the liver must be evaluated very carefully before they undergo surgery. It must be assured that both the volume of the transplanted portion and of the remaining liver is sufficient for recipient and donor. Additionally, there are anatomical variants in the vascular or biliary systems that complicate the operation or even interdict it. Examples of these variants are an accessory hepatic vein or an abberant hepatic artery. New surgical strategies such as anatomical resections of tumors created a demand for more careful preoperative planning of the resection, taking into account the volume of the resected portion of the liver. Preoperative planning is also important in case of multiple liver metastases to decide, whether surgery can be performed in an one-stage approach or if the remaining volume would not be sufficient and therefore the tumors must be resected in several stages with intermittent intervals of organ recovery. To calculate vascular territories and their volumes, it is necessary to segment the liver and the major vessels. Only a few groups world-wide deal with image analysis for liver surgery planning. A group in France has developed methods for the analysis of clinical data for liver surgery planning [2]. Liver segmentation as well as the segmentation of intrahepatic structures are carried out fully automatically. The underlying idea for the automatic liver segmentation