基于亚像素位移的显微CT部分体效应抑制研究  

Micro-CT Imaging with Sub-Pixel Scanning for Suppression of Partial Volume Effect

作　　者：王天舒 李静 罗守华[1] WANG Tianshu;LI Jing;LUO Shouhua(School of Biological Science and Medical Engineering,Southeast University,Nanjing Jiangsu 210000,China)

机构地区：[1]东南大学生物科学与医学工程学院,江苏南京210000

出　　处：《中国医疗设备》2021年第1期75-78,共4页China Medical Devices

基　　金：国家重点研发计划(2017YFA0104302);国家自然科学基金(61871126)。

摘　　要：探测器分辨率不足引起的部分体效应(Partial Volume Effect,PVE)会降低高分辨显微CT的重建分辨率并影响重建图像量化分析的准确性。为了提高该显微CT系统重建图像的空间分辨率,本文提出一种基于纳米载物台抖动的高分辨显微CT重建算法(De-PVE FDK,DP-FDK)。该方法将高精度的纳米载物台固定在旋转台上用于控制待测物体的位置,并设计亚像素尺度下移动纳米载物台获取多张投影图的扫描方案;通过Insight Segmentation and Registration Toolkit平台计算并校正待测物体的亚像素位移向量,最后上采样重建网格并将投影图的亚像素位移信息与FDK重建反投影过程相结合从而提升高分辨显微CT分辨率。仿真及实际实验结果表明,该重建方法能够降低PVE效应,提升重建图像分辨率。The partial volume effect(PVE)caused by insufficient resolution of the detector will degrade the spatial resolution of lenscoupled micro-CT(LCMCT)and affect the accuracy of the quantitative analysis of the reconstructed image.In this paper,we propose a De-PVE FDK(DP-FDK)algorithm to improve the spatial resolution of LCMCT.In this method,the high-precision nanocrystals are fixed on the rotary table to control the position of the object to be measured,and the scanning scheme of moving nanocrystals at the sub-pixel scale to obtain multiple projection images is designed.By measuring and calibrating the sub-pixel displacement vector based on the Insight Segmentation and Registration Toolkit platform,sub-pixel displacement information can be incorporating into conventional FDK algorithm via up-sampling the data grid,thus,the spatial resolution of LCMCT can be greatly improved.The numerical simulations and real experiments indicate that the DP-FDK algorithm can reduce the PVE and improve the resolution of the reconstructed images.

关 键 词：FDK算法 高分辨显微CT 空间分辨率 亚像素 

分 类 号：R197.39[医药卫生—卫生事业管理] O348[医药卫生—公共卫生与预防医学]