摘要
目的基于相似性测度实现周期运动靶区的4D-CT重建。方法自制能模拟呼吸运动的体模,用16排螺旋CT机对体模进行螺旋扫描和电影(Cine)模式扫描;用VC++程序设计语言和VTK工具包,开发了CT图像分相位排序的4D-CT重建软件系统;根据相邻图像互信息量的计算(即相似性测度),把Cine模式扫描的CT图像按相位进行了排序并分别对不同相位的CT图像序列进行三维重建。结果不同相位CT序列的3D重建明显地消除了运动伪影,与静态扫描重建结果相近。随时间变化的多个相位的3D-CT构成了4D-CT序列。结论基于相似性测度能在普通CT上实现4D-CT重建,其重建过程不受CT机本身的软硬件限制具有普遍适用性。
Objective To investigate the feasibility of a 4D - CT reconstruction of periodical motion target based on the similarity measure of spatial adjacent images. Methods A motor driven sinusoidal motion platform made in house was used to create one - dimensional periodical motion that was along the longitudinal axis of the CT couch. CT data of the phantom were acquired using a multi -slice General Electric （GE） LightSpeed 16 - slice CT scanner in an axial mode and Cine mode. A software program was developed by using VC ＋ ＋ and VTK software tools to sort the CT data and reconstruct the 4D - CT. Then all of the CT data with same phase were sorted by the program into a same series based on the similarity measure of spatial adjacent images, and 3D reconstruction of different phase CT data were completed by using the software. Results Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were reduced a lot, and all of the sorted CT series result in a 4D - CT that reflected the characteristic of the periodical motion phantom. Condusions Time - resolved 4D - CT reconstruction of periodical motion target can be implemented with any general multi - slice CT scanners based on the similarity measure of spatial adjacent images, the process of the 4D - CT data acquisition and reconstruction was not restricted to the hardware or software of the CT scanner and has the feasibility and extensive applicability.
出处
《中国辐射卫生》
2009年第1期35-37,共3页
Chinese Journal of Radiological Health
基金
广东省科技计划项目(2007B031509009)
广州市属高校科技计划项目08A008
广东省医学科研究基金项目(A2007290)
关键词
体模
四维计算机断层图像重建
相似性
运动伪影
互信息
Phantom
Four dimensional computed tomography （4D - CT） reconstruction
Similarity
Motion arti- facts
Mutual information
