Key Technology Research Of Intrahepatic Vascular Modeling In Multi-phase Contrast-enhanced CT Images

With the development of computer technology and digital image processing,computer-aided surgery has made great progress.The liver surgery planning is of high value to improve treatment efficacy as well as life qualities of patients.In a computer-aided diagnosis and surgical planning system,constructing high quality geometric computer models of the vessel systems in the liver is a critical step,especially for hepatic vein and portal vein.Multi-phase CT series are often used for the modeling while different vessel systems can be extracted in different phases.Nonetheless,the vessel systems extracted in hepatic venous phase always contains not only the whole hepatic vein but also a part of portal vein.Furthermore,influenced by the body movement and respiration,the shape and location of organs often cannot be reproduced with high fidelity.This thesis focuses on several key technical problems of intrahepatic vessels modeling.Firstly,an automatic framework with minimal user interactions for intro-hepatic veins extraction in contrast-enhanced CT images is presented,which is suitable for the extraction of both portal venous phase and hepatic venous phase.Secondly,the segmented liver containing vascular system from different phases is modeled as a complex shape,and a two-step registration method is proposed.Finally,the remaining portal veins in hepatic venous phase are deleted using the portal vessel system from portal venous phase as prior information.The methods and frameworks described above are integrated into our cloud medical image processing platform(Ray Plus)to retrieve complete and accurate hepatic vessel systems.Several clinic CT series are used for the evaluation with precision and robustness.