多期对比增强超低剂量CT成像方法及应用

血管、实质脏器多期对比增强CT成像是临床应用最广的影像检查手段之一。然而，碘对比剂相关不良反应，多期扫描X线辐射剂量急速攀升，是限制其在心血管、肿瘤早筛和复查等应用的主要瓶颈。采用适宜的对比剂注射方案、开展个体化的CT扫描技术、实现低/超低剂量的优质CT成像是亟待攻克的重大临床问题。基于此，本项目拟开展：（1）依托涵盖受检者身型与心功能、增强CT全流程质控参数的大样本数据集，通过融合刻画数据误差的统计模型和成像机理模型，构建个体自适应的多期对比增强CT成像方案；（2）建立耦合对比剂注射方案及其碘的k边缘效应与CT扫描参数的成像模型，结合高维正则化学习方法实现特征筛选和图像质量综合优化，构建低/超低剂量CT图像重建算法；（3）通过引入持续学习法，开发个体化的超低剂量多期对比增强CT成像体系，开展临床示范应用。本项目将为临床提供个体化的低对比剂用量、低辐射剂量和高质多期图像的CT检查优化方案。

Multi-phase contrast-enhanced CT imaging of blood vessels and parenchymal organs is one of the most widely used imaging exam approach in clinical practice. However, the contrast medium-related adverse reactions and rapid increase of X-ray radiation dose from multi-phase scanning have been the main bottlenecks which limit its application in cardiovascular, early screening and re-examination of tumors and so on. High-quality CT imaging at low/ultra-low doses with the use of appropriate contrast media injection protocols and individualized CT scanning technology is a major clinical issue that need to be overcome. To this end, this project aims to carry out: (1) Based on the large sample dataset including the patients’ body size and cardiac function, and contrast enhanced CT parameters with all-process quality control, an individual-adaptive multi-phase contrast-enhanced CT imaging scheme will be constructed by fully fusing the imaging fundamentals-based mechanism model and the statistical model characterizing the data error; (2) Imaging model coupled with contrast medium protocol and its iodine k edge effect and CT scanning parameters will be established, and low-dose and ultra-low-dose CT image reconstruction algorithms will be constructed with high-dimensional regularization learning method to achieve feature screening and comprehensive optimization; (3) Through the introduction of continuous learning methods, we will develop an individual-adaptive ultra-low-dose multi-phase contrast-enhanced CT imaging system and carry out the pilot applications. This project will provide an individualized CT examination optimization scheme with low contrast medium dosage, low radiation dose and high-quality multi-phase images for clinical practice.