摘要
四维计算机断层扫描(Four-dimensional computed tomography,4D CT)通过对病人多个呼吸周期进行连续扫描,可以提供肺部全方位的动态信息,对肺部肿瘤的诊断、跟踪和放疗具有重要的作用。本文提出了一种基于B样条形变模型的四维图像配准算法对病人肺部的呼吸运动进行估计。为了充分利用4D CT的时间连贯性信息,保证4D CT配准的稳定性,定义了一个新的图像相似性测度函数,并采用迭代的方法对变形场进行优化求解。实验中,通过和成对三维B样条配准算法进行对比来验证本文算法性能。实验证明:所提的4D CT形变配准算法更加精确和稳定,配准精度可以达到1.22±0.74mm。最后作为应用,对7位病人吸气末相位到呼气末相位的呼吸运动进行估计,并给出了统计结果。
Four-dimensional computed tomography （4D-CT） has been developed as a new imaging technology recently.By scanning the multi-breath cycle of the patient continuously,it can provide full range of lung dynamic information and plays an important role in the diagnosis,tracking and radiotherapy of lung cancer.A B-spline deformable model based registration algorithm is proposed for the accurate estimation of lung respiratory motion using 4D CT data.A new image similarity measure is defined to take advantage of temporal coherence information of 4D CT and guarantee the stability of registration.Meanwhile,the deformation field between end-inhale phase CT and other respiratory phase CT is refined by an iterative way.The registration algorithm is evaluated by comparing with pairwise 3D B-spline based registration algorithm according to simulated ground-truth deformation field.The results demonstrate that the proposed algorithm is more accurate and stable,and it can yield a registration error of 1.22±0.74 mm.Finally,the algorithm is applied to 4D CT data of seven patients to estimate the lung respiratory motion between end-inhale and end-exhale phases.
出处
《数据采集与处理》
CSCD
北大核心
2013年第5期608-613,共6页
Journal of Data Acquisition and Processing
关键词
图像形变配准
呼吸运动
时间连贯性
三维渲染
4D
CT
deformable image registration
respiratory motion
temporal coherence
3D rendering
4D CT
