MODEL-BASED SCATTER CORRECTION IN PET

PET 中基于模型的散射校正

• 批准号: 3199417
• 负责人: JOHN M OLLINGER
• 金额: $ 13.73万
• 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 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3199417
• 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及定量 研究扫描的准确性通过准确校正以下影响来实现 康普顿散射。康普顿散射的当前校正方法 缺乏三个方面：(1)他们假设散射 介质是均匀的；(2)它们将散射视为二维 现象，忽略来自相邻切片的散布；以及(3)它们是 基于经验的，尽管康普顿的物理散射 都是众所周知的。这些缺点在心脏扫描中更加明显， 目前最具临床意义的扫描，对于两个 原因：首先，散射是图像质量下降的一个主要来源 在那里遇到较长路径长度的胸部原因；以及 其次，肺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布 修正，对散射介质不做任何假设，采用 考虑到散布的三维性质，并基于 康普顿散射的基本物理模型。通过适当地 将该方法描述为光线跟踪算法，计算 复杂性比可能预期的降低了N倍， 从而使该算法在目前的计算机上具有实用价值。 可用的处理器。 该算法的初步版本是基于以下内容开发的 几个限制性假设。初步的幻影研究表明， 该算法的完全开发版本将显著提高性能 比目前的方法更好的散射校正。的具体目标 这项建议是为了：(1)将初步版本发展到要点 可用于临床；(2)评价本系统的性能 方法；(3)将算法扩展到适用于全三维PET系统；(4) 评估3D模型的性能；以及(5)制定 适用于高速处理器的算法。 方法包括使用数学建模、模型研究和 先前获得的临床正电子发射计算机断层扫描数据。这个项目将会被执行 与神经科、放射科学系合作， 和内科。