Wang Ge, Zhao Shiying, Heuscher Dominic
Department of Radiology, University of Iowa, Iowa City 52242, USA.
Med Phys. 2002 Aug;29(8):1807-22. doi: 10.1118/1.1494989.
With the introduction of spiral/helical multislice CT, medical x-ray CT began a transition into cone-beam geometry. The higher speed, thinner slice, and wider coverage with multislice/cone-beam CT indicate a great potential for dynamic volumetric imaging, with cardiac CT studies being the primary example. Existing ECG-gated cardiac CT algorithms have achieved encouraging results, but they do not utilize any time-varying anatomical information of the heart, and need major improvements to meet critical clinical needs. In this paper, we develop a knowledge-based spiral/helical multislice/cone-beam CT approach for dynamic volumetric cardiac imaging. This approach assumes the relationship between the cardiac status and the ECG signal, such as the volume of the left ventricle as a function of the cardiac phase. Our knowledge-based cardiac CT algorithm is evaluated in numerical simulation and patient studies. In the patient studies, the cardiac status is estimated initially from ECG data and subsequently refined with reconstructed images. Our results demonstrate significant image quality improvements in cardiac CT studies, giving clearly better clarity of the chamber boundaries and vascular structures. In conclusion, this approach seems promising for practical cardiac CT screening and diagnosis.
随着螺旋/多层CT的引入，医用X射线CT开始向锥形束几何结构转变。多层/锥形束CT的更高速度、更薄切片和更宽覆盖范围显示出动态容积成像的巨大潜力，心脏CT研究就是主要例子。现有的心电图门控心脏CT算法已取得令人鼓舞的结果，但它们未利用心脏的任何随时间变化的解剖信息，需要重大改进以满足关键的临床需求。在本文中，我们开发了一种基于知识的螺旋/多层/锥形束CT方法用于动态容积心脏成像。该方法假定心脏状态与心电图信号之间的关系，例如左心室容积作为心动周期的函数。我们基于知识的心脏CT算法在数值模拟和患者研究中进行了评估。在患者研究中，首先根据心电图数据估计心脏状态，随后用重建图像进行细化。我们的结果表明心脏CT研究中的图像质量有显著改善，腔室边界和血管结构的清晰度明显更好。总之，这种方法对于实际的心脏CT筛查和诊断似乎很有前景。
