Single Scan Rest/Stress Cardiac PET Imaging

描述(申请人提供)：冠状动脉疾病(CAD)是西方世界导致死亡和残疾的主要原因。由于冠心病的信号事件通常是猝死或心肌梗死，人们一直致力于开发新的非侵入性成像技术来识别有冠心病风险和/或其破坏性后果的患者。采用新型血流示踪剂18F-BMS的正电子发射断层扫描(PET)是近年来出现的利用门控成像技术检测和定位CAD、量化心肌血流和表征室壁运动异常的最有前途的方法之一。目前使用正电子发射计算机断层扫描(PET)或单光子发射计算机断层扫描(SPECT)进行静息/负荷心肌灌注成像的方法需要分别在静息状态和药物或运动诱导的心脏应激状态下进行成像。这种重复成像需要后处理静息-应力图像联合配准，耗时、低效、对患者来说繁重，并且需要重复传输或CT扫描以进行衰减校正，从而增加对患者的辐射。在这个R21项目下，我们提出了一种新的18F-BMS心脏PET方案，该方案基于双注射单次扫描技术，用于快速静息/负荷成像。在这种方法中，只需执行一次扫描即可完成REST/STREST方案。在开始时，患者在休息时注射示踪剂，采集动态数据，然后在大约5-10分钟(最佳延迟待定)后，给患者施加药物压力，并在不中断扫描的情况下进行第二次示踪剂注射(压力下)。第二次注射后，继续数据采集5-10分钟(持续时间有待优化)。使用基于新的多态动力学隔室模型的信号分离技术，从数据中计算出分离的静息和应力图像以及血流灌注的定量参数。所提出的多状态单扫描技术具有几个优点。由于完成静息/负荷心肌研究方案所需的时间很短，这将大大增加患者的吞吐量和扫描仪的利用率。评估冠状动脉血流储备(CFR)所需的静息图像和负荷图像之间的配准将得到改善，因为患者不会在静息和负荷研究之间移动。这种新方法还可以减少患者的辐射剂量，因为只需要一次x射线CT扫描。在分离静息和应力信号时，所提出的信号分离算法比目前采用的简单的背景减除技术更强大。虽然在这项工作中我们主要关注心脏18F-BMS，但在这项资助下开发的技术也将直接适用于使用其他示踪剂的心脏成像。通过提供一种更快、更安全、更有效的PET定量灌注成像方法，多状态心脏PET成像在改善心脏患者护理方面具有巨大的潜力。

DESCRIPTION (provided by applicant): Coronary artery disease (CAD) is the leading cause of mortality and disability in the western world. Since the signal event of CAD is often sudden death or myocardial infarction, great energy has been focused on developing new noninvasive imaging technologies to identify patients at risk for CAD and/or its devastating consequences. Positron emission tomography (PET) with the new flow tracer 18F-BMS is one of the most promising methods for detecting and localizing CAD, quantifying myocardial blood flow, and characterizing wall motion abnormalities using gated imaging techniques that have emerged in recent years. Current approaches to rest/stress myocardial perfusion imaging with either PET or Single-Photon Emission Computed Tomography (SPECT) require separate imaging at rest and under pharmacologic- or exercise-induced cardiac stress. Such repeat imaging requires post-processing rest-stress image coregistration, is time-consuming, inefficient, onerous to the patient, and requires repeated transmission or CT scans needed for attenuation correction that increase radiation does to the patient. Under this R21 project, we propose a new protocol for 18F-BMS cardiac PET based on a dual-injection single-scan technique for rapid rest/stress imaging. In this approach only a single scan is performed to complete the rest/stress protocol. At the beginning patient is injected with tracer at rest, dynamic data is acquired, and then after about 5-10 minutes (optimal delay to be determined) patient is stressed with the pharmacologic agent and a second administration of tracer (at stress) is performed without interrupting the scanning. Following the second injection, data acquisition is continued for another 5-10 minutes (duration to be optimized). Separate rest and stress images and quantitative parameters of perfusion are calculated from the data using signal separation techniques based on new multi-state kinetic compartmental models. The proposed multi-state single-scan technique offers several advantages. It would substantially increase patient throughput and scanner utilization due to the short time needed for completing the rest/stress myocardial study protocol. The coregistration between images at rest and stress needed for estimation of coronary flow reserve (CFR) would be improved because patients are not moved between rest and stress studies. The new approach also comes with benefits to the patient in reduced radiation dose because only one x-ray CT scan is necessary. The proposed signal-separation algorithms are more powerful than the simple background subtraction technique currently being employed when separating rest and stress signals. Although in this work we concentrate on cardiac 18F-BMS, the techniques developed under this grant will also be directly applicable to cardiac imaging with other tracers. Multi-state cardiac PET imaging has great potential to improve cardiac patient care by providing a faster, safer, and more effective way of performing quantitative perfusion imaging with PET.