Cone-Beam Methods for Dynamic Volumetric X-Ray CT

描述（由申请人提供）： 目前，医用CT扫描仪正处于快速发展之中，锥角越来越大，而生物医学微型CT扫描仪已经处于锥束几何形状。尽管锥束CT的重要性，锥束图像重建算法没有完全开发。有一个关键和迫切需要的动态容积性能的锥束CT，受到多重约束，如剂量，噪声，范围，对比度等，该项目的总体目标是开发和优化分析锥束算法，重点是高时间分辨率和短扫描范围，并直接适用于主要应用，如心脏成像，CT荧光透视，灌注研究，CT血管造影、肿瘤成像、小动物成像以及PET和SPECT。该项目基于最新的锥束CT结果，分别侧重于Feldkamp型、Grangeat型和Katsevich型框架下的近似和精确重建。具体目标是：（1）通过扫描模式设计和加权方案优化，改进Feldkamp型半扫描重建算法，（2）通过锥束数据校正，扩展Grangeat型半扫描重建算法，将Radon空间重建转换为滤波反投影格式;（3）通过检测覆盖最小化和基于n-PI几何的公式化修改Katsevich型动态重建算法;（4）通过理论分析、数值模拟和体模实验对所提出的锥束算法进行了评价和验证，并在小鼠和患者研究中证明了它们的可行性和实用性。完成后，将系统地开发出上级和实用的锥束算法，并为动态容积CT和微型CT提供出色的图像质量。这些算法将在PC集群上实现。这些算法的优势将在小鼠和患者研究中得到证明。

DESCRIPTION (provided by applicant): Currently, medical CT scanners are under rapid development with an increasingly larger cone angle, while biomedical micro-CT scanners are already in cone-beam geometry. Despite the importance of cone-beam CT, cone-beam image reconstruction algorithms are not fully developed. There is a critical and immediate need for a dynamic volumetric performance of cone-beam CT, subject to multiple constraints such as dose, noise, range, contrast, etc. The overall goal of this project is to develop and optimize analytic cone-beam algorithms with an emphasis on high temporal resolution and short scan range, and directly applicable to major applications such as cardiac imaging, CT fluoroscopy, perfusion studies, CT angiography, oncologic imaging, small animal imaging, as well as PET and SPECT. This project is based on the latest cone-beam CT results, and focuses on both approximate and exact reconstruction in the Feldkamp-type, Grangeat-type and Katsevich-type frameworks respectively. The specific aims are to (1) improve Feldkamp-type algorithms for less than half-scan data by scanning pattern design and weighting scheme optimization; (2) extend Grangeat-type half-scan algorithms for long object reconstruction by correcting cone-beam data, and transform the Radon space based reconstruction into the filtered backprojection format; (3) modify Katsevich-type algorithms for dynamic reconstruction by detection coverage minimization and n-PI geometry-based formulation; and (4) evaluate and validate the proposed cone-beam algorithms in theoretical analysis, numerical simulation and phantom experiments, and demonstrate their feasibility and utilities in mouse and patient studies. On completion, superior and practical cone-beam algorithms will have been systematically developed with excellent image quality for dynamic volumetric CT and micro-CT. These proposed algorithms will have been implemented on a PC cluster. The advantages of the algorithms will have been demonstrated in mouse and patient studies.