论文部分内容阅读
为了设计螺旋CT三维血管成像的合理扫描条件、重建方法，探讨其肺血管三维成像的显示级别和伪影的形成机制、影响因素，对离体人、狗心肺各两具行肺血管灌注后充气，当pitch为1时，观察不同层厚、FOV和重建间隔对用表面覆盖法进行肺血管三维成像的影响。结果：①扫描层厚越薄，FOV越小，重建间隔适当缩小，肺血管的显示级别升高。②阶梯伪影由不连续内插算法引起，与床进速度和重建间隔有关。③拉长伪影决定于层敏感性，受床进速度、pitch和内插算法影响。表明螺旋CT肺血管三维成像受诸多成像因素影响，需合理选择。
In order to design a reasonable scanning condition and reconstruction method of three-dimensional spiral CT angiography, the formation mechanism and influencing factors of display level and artifact of pulmonary vascular three-dimensional imaging were studied. When the pitch was 1, the effects of different layer thickness, FOV and reconstruction interval on the three-dimensional imaging of pulmonary vessels by surface coverage were observed. Results: (1) The thinner the scan thickness is, the smaller the FOV is, the shorter the reconstruction interval is, and the higher the level of pulmonary vessels is. ② ladder artifacts caused by discontinuous interpolation algorithm, and the bed into the speed and reconstruction interval. ③ elongated artifacts determined by layer sensitivity, by bed speed, pitch and interpolation algorithm. That spiral CT pulmonary vascular three-dimensional imaging by many imaging factors, to be a reasonable choice.