Principle and Radiation Dose of Energy Imaging for Discovery CT

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 spectral curves.On the other hand,this unique multi-parameter imaging method has also introduced unprecedented challenges to radiologists accustomed to the 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.