基于4D CT的肺部运动呼吸模型

Model of Lung Respiratory Movement Based on 4D CT

肺部的呼吸运动会在图像导航穿刺手术中引入误差,并且该误差是穿刺导航手术的主要误差.为解决该问题,提出了一个接近亚体素级精度、方便易用、运算简便的呼吸模型.首先根据肺内部各标记点的真实运动信息推算运动状态参数;然后根据运动状态参数的运动趋势,提取各点运动的总体规律;最后结合已获得的样本数据,得到一个一般化的呼吸模型.交叉实验结果表明,运用该模型可以将由呼吸引起的原始误差降低75%左右,在呼吸幅度较小的情况下,模型可以达到亚体素级的精度,并且具有运算简便、运用简单的特点.

Lung respiratory movement can cause errors in the operation of image navigation surgery and they are the main errors in the navigation system. To solve this problem,a convenient,simple and easy-to-use breathing model whose precision was close to the sub-voxel was proposed. Motion parameters were first calculated according to the actual lung movement information of each point. The general movement law of each point was then obtained from the movement trend of the motion parameters. Finally a generic lung breathing modelwas constructed based on all the sample data. Results of cross experiments show that the proposed model can reduce the original errors caused by lung breath by about 75%. Besides,in circumstances of lung breath with small amplitude,the proposed model is simple and easy-to-use and can reach the sub-voxel precision.