肝肿瘤热消融三维超声造影可视化导航方法及应用研究

Thermal ablation has become one of the radical therapy methods for small liver cancer. Ultrasound-guided thermal ablation of larger liver tumors requires multiple points and multiple times of needle superposition ablation, which can easily lead to inaccurate distribution of ablation needles in three dimensional space. The existing multimodal fusion navigation technology still have the problems of low registration accuracy and strong subjective dependence on surgical planning due to liver displacement and deformation, which affects the effect of ablation therapy and even results in failure of treatment or serious complications. How to avoid the influence of liver displacement and deformation during thermal ablation and maximize the utilization rate of thermal field by objective and accurate needling in three-dimensional space is one of the key scientific issues urgently needed to be solved. Based on the previous research, in this project we study three key points: the standard of 3D contrast-enhanced image acquisition, reconstruction and visual display, an intelligent automatic planning method of liver puncture path based on big data and image registration and fusion method to realize the 3D reconstruction and operation planning of immediate preoperative contrast-enhanced ultrasound and image fusion with real-time ultrasound during operation. A set of visualization navigation system for thermal ablation of liver tumors was established. It provides a new method for preoperative scientific planning and intraoperative accurate localization of liver tumor thermal ablation.

热消融已成为小肝癌根治性治疗方法之一。超声引导下较大肝肿瘤的热消融治疗，需要多点多次进针叠加消融，叠加进针容易造成消融针在三维空间分布不精确甚至偏移，导致热场重复覆盖或覆盖不全。现有的多模态融合导航技术仍然存在受肝脏移位及形变影响造成配准精度低及手术规划主观依赖性强的问题，从而影响消融治疗的精准度及疗效，导致治疗失败或严重并发症。因此如何避免热消融时肝脏移位及形变的影响并在三维空间实现客观、精准布针使热场效率最大化是热消融治疗亟需解决的关键科学问题之一。为此本项目拟在以往研究基础上，从三维超声造影图像采集规范标准、重建及可视化显示方法、基于大数据肝脏穿刺路径智能自动规划方法、图像配准融合方法研究三个关键点入手，实现术前即刻超声造影三维重建及手术规划并与术中实时超声图像融合,建立一套肝肿瘤热消融三维超声造影可视化导航系统，为实现肝肿瘤热消融治疗的术前科学规划及术中精确定位提供一种新的方法。

热消融已成为小肝癌根治性治疗方法之一。超声引导下较大肝肿瘤的热消融治疗，需要多点多次进针叠加消融，叠加进针容易造成消融针在三维空间分布不精确甚至偏移，导致热场重复覆盖或覆盖不全。现有的多模态融合导航技术仍然存在受肝脏移位及形变影响造成配准精度低及手术规划主观依赖性强的问题，从而影响消融治疗的精准度及疗效，导致治疗失败或严重并发症。因此如何避免热消融时肝脏移位及形变的影响并在三维空间实现客观、精准布针使热场效率最大化是热消融治疗亟需解决的关键科学问题之一。本项目在以往研究基础上，从三维超声造影图像采集规范标准、重建及可视化显示方法、基于大数据肝脏穿刺路径智能自动规划方法、图像配准融合方法研究三个关键点入手，制定了术前三维超声造影图像采集规范标准，通过构建基于皮尔逊相关系数的手持式及基于四面体结构体插值的三维超声重建算法，及基于时空连续性学习的精确四维超声重建方法，实现了术前即刻三维超声造影图像重建；在团队肝癌患者微波消融规模化数据库基础上，通过海量数据多维特征的关联计算实现了对个体肝癌患者穿刺路径、消融体积、空间布针、热场组合等适形消融方案的优化设计；采用 2D US-3D CEUS 空间定位配准方法，实现了术前即刻超声造影三维重建及手术规划并与术中实时超声图像融合,建立了一套肝肿瘤热消融三维超声造影可视化导航系统，并通过体模、动物实验来验证了系统的精准性及稳定性，动物实验结果显示三维超声造影可视化导航系统平均穿刺误差1.83±1.00mm；进行了三维超声造影可视化导航系统与多模态影像融合导航系统及常规二维超声引导方式穿刺精准性及安全性对比的动物实验研究等，结果显示三维超声造影可视化导航系统与多模态影像导航系统在穿刺精准性及安全性等方面无明显统计学差异（p>0.05），三维超声造影可视化导航系统较常规二维超声引导下消融有更高的一次完全消融率（p=0.027）。该系统为实现肝肿瘤热消融治疗的术前科学规划及术中精准定位提供了一种新的方法。