多层螺旋CT血管造影中的冠脉运动估计

提出了由多层螺旋计算机层析(MSCT)数据估计冠脉三维运动的算法。首先对多期相数据进行基于Hessian矩阵的局部血管增强,随后采用自适应阈值区域生长方法分割出血管并进行细化,得到不同时刻的冠脉骨架。血管进行分段后,利用连贯点漂移(CPD)点配准算法对不同期相的各段血管配准,计算点对之间的对应关系矩阵及空间变换,从而估计三维运动场。采用运动场已知的模拟数据评估算法精度,结果表明,对超过50mm的大幅度运动,配准误差小于1voxel,运动场估计误差小于1%。对实际的全期相数据,估计左右冠脉的运动场,也获得了较为均匀和平滑的结果。

Estimation of coronary artery motion from multi-slice CT angiography

An approach for analyzing 3D cardiac motion from multi-slice computed tomographic(MSCT) angiography data is presented.First,a local vessel enhancement based on Hessian matrix and locally adaptive threshold region growing is applied to extract the 3D coronary arteries model and then 3D thinning is performed and the skeleton on different R-R intervals is obtained.The vessel branches are matched with the coherent point drift(CPD) point set registration algorithm and the correspondence matrix and transformation parameter are calculated,and thus 3D motion is estimated.The algorithm accuracy is quantitatively assessed by using simulated data with known transformation parameters,and the experiment results illustrate that the matching error is less than one voxel and the motion estimation is within 1% for a large-scale motion more than 50 mm.Real clinical full-phase data is also processed and reasonable results are achieved.