双能量CT技术在电子密度测量中的应用

摘要

双能量CT能够准确地测定被扫描物质中原子序数和电子密度的分布,实现物质识别和精确测定,在医疗和安全检查等领域得到了广泛的应用.在质子和重离子放射治疗中,需要精确测定不同组织中的电子密度,为放疗方案的制定提供参考,双能量CT则为电子密度测定提供了一种精确方法.首先介绍了双能量CT技术的发展和图像重建方法以及双能量CT在物质识别、爆炸物检测和医疗等领域的应用.针对电子密度的精确测定,介绍了一种基于同步辐射单色光的后处理双能重建方法,大大提高了电子密度测量的精度.使用同步辐射光源进行的实验结果证明,双能量CT成像可以准确测量扫描物体中的电子密度分布,从而为放射治疗等提供重要参考.%Atomic number and electron density can be obtained by dual - energy CT technique with high precision. Thus, dual - energy CT technique plays an important role in material discrimination, medical diagnosing and safety check. With the development of photon and charged particle radiotherapy treatment, it becomes more and more important to obtain the distribution of electron density. Dual - energy CT offers a solution for electron density measurement. It presents the recent development of dual - energy CT and reconstruction methods, as well as the utility of this technique in electron density measurement. Also it presents a post - processing dual -energy CT reconstruction method for synchrotron x - ray. To improve the precision, we conducted a dual - energy CT imaging experiment with synchrotron radiation facility. The results improves its feasibility that dual - energy technique in electron density measurement.