双能CT的实现方式多种多样，基于双层探测器的能谱CT成像是其中一种新的双能量技术，其使用立体双层探测器 设计，区分一束X射线中的高、低能量数据，一次检查同时提供常规图像以及多参数能量图像。虽然一般认为140 kVp的能 谱分离更好，但基于双层探测器的120 kVp能谱CT成像也可进行足够的能谱分离，和140 kVp在物质定量方面也几乎是等效 的。本文回顾了CT能量成像的技术原理，阐述了双能量CT成像方法，并解读了双层探测器能谱CT图像特点，最后详细地 介绍了近年来双层探测器能谱CT的临床应用，通过本文综述，能让我们更好地运用双层探测器能谱CT来为科研和患者的 临床诊疗提供服务。

Dual-energy CT can be realized in a variety of ways. Energy spectrum CT imaging based on dual-layer detector is one of the new dual-energy technologies. It uses dual-layer detector design to distinguish high and low energy data in a beam of X-rays, and provides both conventional images and multi-parameter energy images in one examination. Although it is generally believed that the energy spectrum separation of 140 kVp is better, 120 kVp energy spectrum CT imaging based on two-layer detector can also perform sufficient energy spectrum separation, and it is almost equivalent to 140 kVp in terms of substance quantification. This article reviewed the CT imaging of energy principle and expounded the dual energy CT imaging method, and interpreted the double probe spectrum characteristics of CT images. Finally, it introduced the clinical application of two-layer detector energy spectrum CT in recent years in detail. It is hoped that through this review, we can better use the two-layer detector energy spectrum CT to provide services for scientific research and clinical diagnosis and treatment of patients.