Advancing energy-resolved CT systems for imaging K-edge contrast agents

描述（由申请人提供）：我们的目标是使用能量分辨CT提供准确的、与对象无关的造影剂浓度估计值。能量分辨CT具有降低CT血管造影检查的造影剂剂量和辐射剂量的潜力。与核医学方法相比，将能量分辨CT与靶向K边缘造影剂相结合有助于定量分子CT，具有提高空间分辨率（亚毫米）、时间分辨率（亚秒）和定量准确性（约5%）的潜力。与传统的双kVp方法不同，能量分辨CT通过其独特的K边缘区分造影剂，从而实现直接量化。然而，能量分辨CT的准确性和扫描时间目前受到技术问题的限制。该项目开发了创新的重建和校正方法，以克服能量分辨CT的局限性，同时提高准确性并降低剂量。这一努力将使这项有益的技术更快地转化为临床。我们假设，所提出的方法将量化造影剂浓度在5%的误差与一秒的扫描时间。具体而言，该项目将： (1)开发一种实用的光谱响应校正方法，（2）开发感兴趣区域材料分解算法，以减少剂量和脉冲堆积效应，以及（3）开发一种同时估计造影剂和散射的方法。这些方法将通过在我们的原型能量分辨CT系统上的幻影和动物实验进行测试。该项目的成功完成将减少CT血管造影的辐射和对比剂量，并在与靶向示踪剂结合时提供有关生理功能和疾病状态的重要信息。

DESCRIPTION (provided by applicant): Our goal is to provide accurate, object-independent estimates of contrast-agent concentration using energy- resolved CT. Energy-resolved CT has the potential to reduce the contrast dose and radiation dose of CT angiography exams. Combining energy-resolved CT with targeted K-edge contrast agents facilitates quantitative molecular CT, with the potential for improved spatial resolution (sub-mm), temporal resolution (sub-second) and quantitative accuracy (~5%) compared to nuclear medicine methods. Unlike conventional dual-kVp methods, energy-resolved CT distinguishes contrast materials by their distinct K-edge, enabling direct quantification. However, the accuracy and scan time of energy-resolved CT is currently limited by technological issues. This project develops innovative reconstruction and correction methods to overcome the limitations of energy-resolved CT, while increasing accuracy and reducing dose. This effort will enable faster translation of this beneficia technology into the clinic. We hypothesize that the proposed methods will quantify contrast-agent concentration to within 5% error with a one-second scan time. Specifically, the project will: (1) develop a practical spectral-response correction method, (2) develop region-of-interest material decomposition algorithms to reduce dose and pulse-pileup effects, and (3) develop a method for simultaneous estimation of contrast agent and scatter. The methods will be tested through phantom and animal experiments on our prototype energy-resolved CT system. Successful completion of the project will reduce radiation and contrast dose of CT angiography and provide important information about physiological function and disease states when combined with targeted tracers.