Design of Path-Planning System for Interventional Thermal Ablation of Liver Tumors Based on CT Images

Abstract

Objective: Aiming at the shortcomings of artificial surgical path planning for the thermal ablation of liver tumors, such as the time-consuming and labor-consuming process, and relying heavily on doctors' puncture experience, an automatic path-planning system for thermal ablation of liver tumors based on CT images is designed and implemented.

Methods: The system mainly includes three modules: image segmentation and three-dimensional reconstruction, automatic surgical path planning, and image information management. Through organ segmentation and three- dimensional reconstruction based on CT images, the personalized abdominal spatial anatomical structure of patients is obtained, which is convenient for surgical path planning. The weighted summation method based on clinical constraints and the concept of Pareto optimality are used to solve the multi-objective optimization problem, screen the optimal needle entry path, and realize the automatic planning of the thermal ablation path. The image information database was established to store the information related to the surgical path.

Results: In the discussion with clinicians, more than 78% of the paths generated by the planning system were considered to be effective, and the efficiency of system path planning is higher than doctors' planning efficiency.

Conclusion: After improvement, the system can be used for the planning of the thermal ablation path of a liver tumor and has certain clinical application value.

Keywords: Pareto optimality; surgical planning; system design; thermal ablation of tumors; weighted summation.

Figure 1

Functional module of liver tumor thermal ablation surgery path-planning system.

Figure 2

Image segmentation and 3D visualization module usage flow chart.

Figure 3

The usage flowchart of the automatic surgical path-planning module.

Figure 4

Pareto coordinate system constructed by “actual length of puncture path” and “distance to risk structure”.

Figure 5

Surgical path-planning system interface.

Figure 6

“Segmentation and Reconstruction” page of the surgical path-planning system.

Figure 7

Isosurface rendering results of critical structures segmented in CT image by our system. (a–f) Volume rendering of segmented liver, liver tumor, skin, bone, lung, and liver vessel.

Figure 8

Interactively adjusted surgical path system interface. “Optimal Path Evaluation”: The planning parameters for the automatically planned ablation needle puncture path. “Optimal” refers to the needle target with the highest score evaluation within the feasible injection area. “Interactive Path Evaluation”: Specify a new puncture starting point coordinate to generate a new ablation needle puncture path, and display the planning parameters of the interactively adjusted ablation needle puncture path.