基于脊线预配准的肋骨骨折钢板预弯算法研究

Study of a plate prebending algorithm for costal fracture operation based on pre-registration of ridge lines

提出了一种可以在肋骨骨折手术前获取目标固定钢板几何参数的仿真方法。其主要操作步骤包括：通过CT扫描获取骨折部位的序列断层图像，利用Curvelet变换对CT序列图像进行去噪处理并建立三维模型；根据肋骨的形状特征，提取两段断骨的脊线进行空间预配准；并驱动两段断骨进行模型预配准。使用网格模型内三角面片的面积特征分割得到两个断骨截面；采用基于非迭代估计的配准方法对两个断骨截面进行配准操作，并驱动两个断骨进行模型精配准；拟合出预弯钢板的形态，测量其几何参数。通过对两例成年肋骨骨折进行的模拟实验，证明此方法可以精确地建立预弯钢板模型，缩短手术时间，提高手术质量。

The paper proposes a novel simulation method which can obtain geometric parameters of the target fixation plate before costal fracture operation. Its main processing scheme consists of following steps： Firstly, the Curvelet transform is utilized to denoise CT images of the fracture part and its 3-D reconstruction is implemented; Secondly, ridge lines of fractured bones are extracted and spatially aligned, and synchronously, the fractured bone models are driven to pre-register; Thirdly, a method based on triangular face area feature is utilized to obtain fractured bone section; Fourthly, a method based on non-iterative estimation is used to align sections. Synchronously, fractured bone models are driven to close register; Finally, an accurate NURBS surface fitting method is used to fit the plate, and geometric parameters are measured. Two costal fracture cases were chosen as the experimental subjects, and the experimental results proved the proposed method could construct the prebent plate model precisely, which would shorten the operating time and improve the quality.