Supplemental transmission aided attenuation correction for high performance quantitative PET imaging

项目摘要 来自组合PET-CT和PET-MR的定量示踪剂图像越来越多地用于放射学检查。 决策和临床试验。基于CT和MR的PET光子衰减数据校正，通常 对示踪剂定量的最大影响，可能导致对受试者的辐射剂量增加或需要长时间的 额外的专用MR扫描。使用源自对象的PET信号的算法， 联合估计衰减和示踪剂对比度已经被提出作为鲁棒的替代方案，但是， 日期，未能匹配CT方法的量化。因此，没有单一的PET方法 衰减校正可产生高定量，且不会影响患者安全性或通量 目前存在。这是一个重要的问题，因为研究和临床发现必须平衡这些实际问题。 数据质量问题。本提案的总体目标是开发和表征一种高 性能衰减校正方案，其利用来自受试者的PET信号和变量 活动外部来源。中心假设是，所提出的重建方法将具有 与仅使用源自受试者的PET信号的算法相比，性能显著提高， 独立于成像研究。这两个具体目标包括：1）开发和验证补充 用于校正PET图像在商业PET期间的光子衰减的基于透射的算法 成像和2）原型设计和表征能够动态改变外部源活动的装置。 目标1的结果将是一种重建算法，该算法经过优化以产生定量PET数据， 一些最常见的临床PET研究。在目标2下，可以重复性改变 外部源活动，以最大限度地提高示踪剂定量，同时最大限度地减少不可避免的退化 对于患者，将产生由任何外部源的引入引起的示踪剂图像噪声。的 创新是一种衰减校正策略，它大大减轻了以前联合 提供定量PET诊断的重建方法，预期可与银相匹配 标准CT方法。这是重要的，因为接受脑和心脏PET的患者数量- CT扫描，检查所提出的方法预计将受益，正在稳步增加。对于PET-MR， 可以改善MR性能有限的示踪剂定量，并通过以下方式增加患者吞吐量： 消除了对非诊断性的仅衰减MR采集的需要。因此，拟议战略 极大的潜力，以显着改善放射决策和临床试验结果，依赖于 定量PET摄取测量。

PROJECT SUMMARY Quantitative tracer images from combined PET-CT and PET-MR are increasingly being utilized for radiological decision-making and clinical trials. CT and MR based data corrections for PET photon attenuation, typically the largest impact on tracer quantification, can lead to increased radiation dose to the subject or require lengthy additional dedicated MR scans, respectively. Algorithms using the PET signal originating from the subject to jointly estimate both the attenuation and tracer contrast have been proposed as robust alternatives, but, to date, have failed to match the quantification of CT approaches. Consequently, no single approach for PET attenuation correction that produces high quantification and does not compromise patient safety or throughput currently exists. This is an important problem, since research and clinical findings must balance these practical issues with data quality. The overall objective of this proposal is to develop and characterize a high performance attenuation correction scheme that utilizes both the PET signal from the subject and a variable activity external source. The central hypothesis is that the proposed reconstruction method will have significantly improved performance over algorithms using PET signal originating from the subject alone, independent of the imaging study. The two specific aims include: 1) developing and validating a supplemental transmission-based algorithm for correcting PET images for photon attenuation during commercial PET imaging and 2) prototyping and characterizing a device capable of dynamically varying external source activity. The result of Aim 1 will be a reconstruction algorithm that is optimized to produce quantitative PET data for some of the most common clinical PET studies. Under Aim 2, a prototype device that can repeatability vary the external source activity in order to maximize tracer quantification while minimizing the unavoidable degradation to patient tracer image noise, caused by the introduction of any external source, will be produced. The innovation is an attenuation correction strategy that greatly mitigates the limitations of previous joint reconstruction methods to deliver quantitative PET diagnostics that are expected to match those of silver standard CT approaches. This is significant because the number of patients receiving brain and cardiac PET- CT scans, exams the proposed method is expected to benefit, is steadily increasing. For PET-MR, the method may improve tracer quantification where MR has limited performance and increase patient throughput by eliminating the need for non-diagnostic attenuation-only MR acquisitions. Thus, the proposed strategy has great potential to significantly improve radiological decision-making and clinical trial findings that rely on quantitative PET uptake measurements.