目前CT已成为疾病诊断的一种重要手段.与常规CT相比,能谱CT最显著的特征就是提供了多种定量分析工具与多参数成像为基础的综合诊断模式,如基物质图像、单能量图像、能谱曲线等.其独特的多参数成像模式给长期习惯于单一诊断模式的影像科医生提出了前所未有的挑战,熟悉其成像原理、影像表现与应用价值是非常必要的.本文首先回顾了能量CT研发的必要性及其实现途径；随后深入剖析了单源瞬时kVp切换能谱成像的物理基础,并介绍了实现该技术所必需的解析技术；接着从基础实验的角度,展现了能谱成像能够在更低剂量条件下保证同常规CT一致的图像质量.%Computed tomography (CT) has become an important modality for diagnosing diseases. The most prominent advantages of Spectral CT which has over conventional CT are its set of quantitative analysis tools as well as its integrated diagnostic method based on multi-parameter images, including material-decomposition images, monochromatic images and spectra! curves. On the other hand, this unique multi-parameter imaging method has also introduced unprecedented challenges to radiologists accustomed to me single-parameter diagnostic mode- It is thus important for radiologists to understand the imaging principles, image appearance, and clinical applications of Spectral CT. This paper begins by reviewing the history of energy CT with emphases on the necessity of the development of energy CT, followed by a thorough analysis of the fundamentals of Spectral CT imaging with single tube-fast kVp acquisition approach in terms of its necessary image generation algorithm, it then demonstrates the ability of Spectral CT imaging in quantification using phantom experiments, and it reveals the tremendous value of Spectral CT in improving image quality as well reducing the radiation dose.
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