基于三维运动轨迹的高分辨显微CT环状伪影去除方法

环状伪影主要源于高分辨显微CT圆轨迹重建,严重的环状伪影会影响重建图像的后续处理及量化分析。为了避免环状伪影引起的图像退化,本文提出了一种基于三维运动轨迹的高分辨显微CT采集与重建的方法。该方法以高分辨显微CT现有结构为基础,利用旋转台和三维平移台形成待测对象的三维空间运动。首先,基于Insight Segmentationand Registration Toolkit平台,模体数据进行配准获取位移矩阵。随后按照设定的三维运动轨迹获得单圈投影数据,最后使用位移矩阵参数进行FDK重建去除环状伪影。本文对含有环状伪影的仿真数据以及实际数据进行了实验,结果表明,该环状伪影去除方法具有去除效果明显、不改变图像分辨率、重建速度快的特点,且适用于各种锥束CT成像系统。

Ring Artifact Correction Method for High-Resolution Micro-CT Based on 3D Motion Trajectory

Ring artifacts are mainly derived from high-resolution micro-CT circular trajectory reconstruction.However,severe ring artifacts will affect the subsequent processing and quantitative analysis of the reconstructed image.In order to eliminate ring artifacts,a high-resolution micro-CT acquisition and reconstruction method based on 3D m otion trajectory was proposed in this paper.Based on the structure of high-resolution micro-CT,this method used a rotating table and a three-dimensional translation platform to realize the 3D motion trajectory of the object.First,based on the Insight Segmentation and Registration Toolkit platform,the phantom data was registered to obtain the displacement matrix.Next,the projection data according to the 3D motion trajectory were obtained.Finally,the circular artifact was removed by FDK reconstruction with the matrix parameters of the 3D motion trajectory.The proposed method was qualitatively and quantitatively evaluated in numerical simulations and real experiments.The results demonstrated that this ring artifact correction method has the characteristics of obvious correction effect,maintaining image resolution,and fast reconstruction speed,which is suitable for various cone beam CT imaging systems.