Simulation Tools for Dynamic CT

描述（由申请人提供）：模拟是表征、评估和优化医学成像系统以及法师处理和重建方法的强大工具。模拟的两个主要组成部分是：（1）人体解剖结构和生理功能的逼真模型，以及（2）生成包括成像过程影响的准确图像数据的能力。如果没有这些，模拟的结果可能无法指示在实际患者中会发生什么，因此将具有有限的实用价值。目前的四维（4D）基于NURBS的心脏躯干（NCAT）体模被开发用于提供人体解剖学和生理学的逼真和灵活的模型，并广泛用于核医学成像研究。由于其设计，体模具有以下优点：其器官形状可以改变，以逼真地模拟不同的解剖变化和患者运动。虽然NCAT体模能够更加逼真，但它是为低分辨率核医学成像研究而设计的，缺乏适用于高分辨率CT的解剖细节。同时，当前用于CT的体模在描绘真实的人体器官的复杂形状方面缺乏足够的真实性，并且在模拟解剖变化和正常生理运动方面缺乏灵活性，这些缺陷随着这些成像技术的快速发展和新应用的开发而变得越来越重要。我们试图通过建立在现有的4D NCAT模型和我们实验室开发的其他模拟工具上来填补这一空白。我们假设，在这项工作中开发的工具将提供模拟的CT图像数据，准确地模仿从实际患者（男性和女性）在不同的发展阶段（成人和儿童）。随着X射线CT发展成为许多新的应用和获得更广泛的使用，在这项工作中开发的模拟工具将在广泛的成像研究中的应用，在开发图像采集策略，图像处理和重建方法，图像可视化和解释技术。此外，这些工具为优化临床CT应用提供了必要的基础，从而以最小的患者辐射剂量获得尽可能高的图像质量。由于辐射问题，以特定于临床需求的方式优化人类患者中现代CT系统中可用的大量成像参数是不切实际的。在不能真实地复制体内观察到的条件的物理测试对象中执行优化同样是不切实际的。这样的任务只能实际和有效地执行使用准确和现实的计算机模拟方法，尚未开发。我们的研究人员和顾问团队在开发数字模型、医学成像过程的精确模型以及非常适合该项目的3D图像重建技术和方法方面拥有广泛的专业知识。

DESCRIPTION (provided by applicant): Simulation is a powerful tool for characterizing, evaluating, and optimizing medical imaging systems and mage processing and reconstruction methods. The two major components of simulation are: (1) a realistic model of the human anatomy and physiological functions, and (2) ability to generate accurate image data that include effects of the imaging process. Without such, the results of the simulation may not be indicative of what would occur in actual patients and would, therefore, have limited practical value. The current four- dimensional (4D) NURBS-based cardiac-torso (NCAT) phantom was developed to provide a realistic and flexible model of the human anatomy and physiology and is widely used in nuclear medicine imaging research. The phantom has the advantage, due to its design, that its organ shapes can be changed to ealistically model different anatomical variations and patient motion. Although capable of being far more realistic, the NCAT phantom was designed for low-resolution nuclear medicine imaging research, and lacks the anatomical detail to be applicable to high-resolution CT. At the same time, current phantoms used in CT lack sufficient realism in depicting the complex shapes of real human organs and the flexibility to model anatomical variations and normal physiologic motion, deficiencies that are becoming increasingly important with rapid advancements in these imaging technologies and in the development of new applications. We seek to fill this void by building upon the existing 4D NCAT phantom and other simulation tools developed in our laboratory. We hypothesize that the tools developed in this work will provide simulated CT image data that accurately mimic that obtained from actual patients (male and female) at different stages of development (adult and pediatric). As x-ray CT evolves into many new applications and gains wider use, the simulation tools developed in this work will have applications in a broad range of imaging research in developing image acquisition strategies, image processing and reconstruction methods, and image visualization and interpretation techniques. Also, the tools provide the necessary foundation to optimize clinical CT applications so as to obtain the highest possible image quality with the minimum possible radiation dose to the patient. Due to radiation concerns it is impractical to optimize the large number of imaging parameters available in modern CT systems in human patients in ways that are specific to clinical demands. It is equally impractical to perform optimizations in physical test objects that cannot realistically duplicate the conditions seen in vivo. Such a task can only be practically and efficiently performed using accurate and realistic computer simulation methods, which have not yet been developed. Our team of investigators and consultants has extensive expertise in developing digital phantoms, accurate models of the medical imaging process, and 3D image reconstruction techniques and methods that are well suited for this project.