螺旋CT扫描与三维成像技术的临床应用

Clinical Application of Spiral CT Scanning and Three-dimentional Imagining Techniques

螺旋 CT是指 X线源旋转及数据收集过程中病人连续平移 ,并在相对短的时间内获取容积数据。螺旋 CT的投影数据常在病人一次屏气内获得 ,数据采集之后即进行内插运算由此解决平均容积伪影的问题及对层面敏感性曲线的影响。 2 0世纪80年代后期三维软件应用于 CT后处理 ,三维图像更加完整、直观、真实的表现人体各种组织结构的主体形态及其相对位置。重建和显示三维 CT图像的方法主要有四种 :线框重建 ,表面重建 ,体素重建 ,彩色分域。目前普遍采用的方法有两种即表面重建和体素重建。总之 ,高质量的三维图像与扫描方式密切相关。三维 CT图像有较强的真实感 ,但也存在一些不足 ,如图像处理时间延长、三维立体影像生硬。但随着科技的发展和软件多种功能的进一步完善 。

A spiral CT can obtain the volume data in the course of the X ray source rotating and data collecting when the patient's moving position always parallels the machine. The projection data are usually obtained in one breathholding. Then interpolation is performed immediately after the data collection, so that the problems of average volume artifact and its effect on the section sensitivity can be resolved.Since the late 1980s, application of three dimensional softwares to CT image after finishing treatment has made three dimensional images of human structures and their relative positions display more completely, directly and really. There are 4 main methods to reconstruct and display three dimensional CT images. Of them the most widely used two are surface reconstruction and voxel reconstruction. High quality three dimensional images are closely related to way of scanning. There are also some weaknesses of three dimensional CT images, such as prolonged image processing time and indistinctive three dimensional stereoscopic images.