Intra-operative Multimodal Non-rigid Registration of the Liver for Navigated Tumor Ablation

摘要

CT guided tumor ablation of the liver often suffers from a lack of visualization of the target tumor and surrounding critical structures. This information is available on pre-operative contrast enhanced MR images and a non-rigid registration technique is desirable. However while registration methods have been successfully tested retrospectively on patient data, very few have been incorporated into clinical procedures. A non-rigid registration technique has been evaluated, optimized and validated to be able to perform registration of the liver between MR to CT images, and between intra-operative CT images. The method requires pre-processing and segmentation of the liver, and presents an accuracy of approximately 2mm. A clinical feasibility study has been conducted in 5 liver ablation cases. The method helps clinicians enhance interven-tional planning, confirm ablation probe location with respect to the tumor, and in the case of cryotherapy, evaluate tumor coverage by the ice ball.