螺旋CT扫描数据的虚拟辅助性部分原位肝移植手术

Virtual Auxiliary Partial Orthotopic Liver Transplantation Surgery Based on Data from Helical-CT Scanning

目的探讨三维可视化及虚拟手术技术在肝移植外科中的意义。方法利用2例胆管结石患者的肝脏64排螺旋CT扫描数据集,人工方法对图像进行分割、配准,采用VTK软件进行三维重建,然后导入到Free-Form Modeling System进行修饰。利用系统的力反馈设备PHANTOM进行辅助性部分原位肝移植手术的仿真研究。结果①重建的肝脏模型具有肝脏、肝动脉、肝静脉、门静脉和胆道系统,形态逼真,立体感强;肝脏可视化后,肝脏内部管道空间立体感强,肝动脉、肝静脉、门静脉和肝胆管的分布、行程以及相互关系明晰。②在建立的虚拟手术系统的虚拟环境中,使用力反馈设备PHANTOM操纵"虚拟手术刀"模拟了辅助性部分原位肝移植的手术过程,其结果符合临床手术的效果;通过控制肝脏模型切除部分的透明度,使肝脏手术切割平面可视化以及肝脏内部管道手术切断平面可视化;手术模拟过程逼真,形象,且有"力"的感受。结论①可视化的肝脏重建模型立体、逼真,有利于肝移植手术方案的合理设计;②肝移植术前的手术设计和可视化演示可提高手术效果,降低手术风险及减少手术并发症,加强医患沟通;③虚拟肝移植手术有利于医务人员的培训和学习。

Objective To investigate the significance of three dimensional （3D） visualization and virtual surgery system in liver transplantation surgery. Methods Two patients suffered from cholangiolithiasis were scanned by 64 slice helical-CT on livers and the data were collected. Man-made segmentation and true up on the image from the data were carried out. 3D moulds of the liver and the intrahepatic vessels were reconstructed by VTK software respectively. And then, the moulds were imported to the FreeForm Modeling System for modifying. At last, auxiliary partial orthotopic liver transplantation was simulated with the force feedback equipment （PHANTOM）. Results （1）It had greatly verisimilar image for the reconstructed 3D liver moulds with artery, vein, portal vein and bile duct; By liver seeing through, it had high fidelity and strong 3D effect for the intrahepatic artery, vein, portal vein and bile duct, and their spatial disposition and course and correlationship were shown clearly. （2）In the virtual surgery system, the virtual scalpel could be manipulated on 3D liver mould with PHANTOM. The simulating effect was the same as the clinic operation for auxiliary partial orthotopic liver transplantation. Plane visualization of hepatic resection and intrahepatic vessel cutting was achieved by adjusting the transparency of the resection part. Life-like could be felt and power feeling could be touched during virtul operation. Conclusion （1）The visualized liver mould reconstructed is 3D and verisimilar, and it is helpful to design reasonable scheme for liver transplantation. （2）It not only can improve the surgical effect and decrease the surgical risk, but also can reduce the complications and enhance the communication between doctor and patient through designing surgical plan and demonstrating visualized operation before surgery. （3）Visualized liver transplantation surgery is helpful for medical workers to train and study.