MODEL-BASED SCATTER CORRECTION IN PET

PET 中基于模型的散射校正

• 批准号: 2096231
• 负责人: JOHN M OLLINGER
• 金额: $ 11.67万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2096231
• 关键词: clinical biomedical equipment; diagnosis quality /standard; heart imaging /visualization /scanning; light scattering; mathematical model; phantom model

The broad goal of this research is to improve the diagnostic accuracy of clinical positron-emission tomography (PET) scans and the quantitative accuracy of research scans by accurately correcting for the effects of Compton scattering. Current methods of correcting for Compton scatter are lacking in three respects: (1) They assume that the scattering medium is homogeneous; (2) They treat scattering as a two-dimensional phenomenon, ignoring scatter from adjacent slices; and (3) They are empirically based, despite the fact that the physics of Compton scatter are well known. These shortcomings are more pronounced in cardiac scans, the scans that are currently of greatest clinical interest, for two reasons: First, scatter is a major source of image degradation in the chest cause of the relatively long path-lengths encountered there; and second, the lungs introduce significant heterogeneities in the scattering medium. The proposed method, termed model-based scatter correction, makes no assumptions about the scattering medium, takes the three-dimensional nature of scatter into account and is grounded in a model of the fundamental physics of Compton scatter. By appropriately formulating the method as a ray-tracing algorithm, the computational complexity is reduced by a factor of n over what might be expected, thereby making the algorithm computationally practical on currently available processors. A preliminary version of this algorithm has been developed based on several restrictive assumptions. Initial phantom studies suggest that a fully developed version of the algorithm will perform significantly better scatter correction than current approaches. The specific aims of this proposal are to: (1) Develop the preliminary version to the point that it can be used clinically; (2) Evaluate the performance of this method; (3) Extend the algorithm for use with fully 3D PET systems; (4) Evaluate the performance of the 3D model; and (5), Formulate the algorithm for use on high-speed processors. Methods include the use of mathematical modeling, phantom studies, and previously acquired clinical PET data. This project will be performed in cooperation with the departments of Neurology, Radiation Sciences, and Internal Medicine.

这项研究的主要目标是提高诊断的准确性， 临床正电子发射断层扫描（PET）和定量 研究扫描的准确性，通过准确校正的影响， 康普顿散射。 康普顿散射的现行修正方法 在三个方面缺乏：（1）他们认为，散射 介质是均匀的;（2）他们把散射作为一个二维 现象，忽略来自相邻切片的散射;以及（3）它们是 尽管康普顿散射的物理学 是公知。这些缺点在心脏扫描中更为明显， 目前临床上最感兴趣的扫描， 原因：第一，散射是图像退化的主要来源， 胸部的原因，相对较长的路径长度遇到那里; 第二，肺在肺中引入了显著的异质性。 散射介质 所提出的方法，称为基于模型的散射 修正，不对散射介质做任何假设， 考虑到散射的三维性质，并以 康普顿散射的基本物理模型。 通过适当 将该方法公式化为射线跟踪算法，计算 复杂度比预期的复杂度降低了N倍， 从而使得该算法在当前的计算机上是实用的 可用的处理器。 该算法的初步版本已经开发基于 一些限制性假设。最初的幻影研究表明， 该算法的完全开发版本将执行显着 比现有方法更好的散射校正。 的具体目标 这一建议是：（1）发展初步版本，以点 它可以用于临床;（2）评估其性能 方法;（3）扩展算法，用于全3D PET系统;（4） 评估3D模型的性能;以及（5），制定 用于高速处理器的算法。 方法包括使用数学建模，体模研究， 之前获取的临床PET数据。 该项目将执行 与神经病学，放射科学， 和内科。