Reliable and Robust ECG Gating Signal for Cardiac MR Imaging

用于心脏 MR 成像的可靠且稳定的心电图门控信号

• 批准号: 7112141
• 负责人: Thomas H Frank
• 金额: $ 90.44万
• 依托单位: PERINATRONICS MEDICAL SYSTEMS, INC.
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-11-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7112141
• 关键词: automated data processing; bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical device power system; biomedical equipment development; clinical research; electrocardiography; fiber optics; human subject; magnetic resonance imaging; myocardium; telemetry

DESCRIPTION (provided by applicant): Magnetic Resonance Imaging (MRI) has become the gold standard for the quantitative assessment of cardiac structure and function. The key to imaging the moving myocardium is a reliable and robust electrocardiogram signal which, used as a "trigger," can provide images at specified phases throughout the cardiac cycle. Stronger field strength magnets, greater magnetic gradient slew rates, and an ever increasing number of magnetic gradient pulse sequences such as those that provide cardiac perfusion have significantly increased the difficulties of triggering. In addition, individuals with sick hearts may have abnormal ECGs. The focus of this Phase II project is to research, develop and clinically evaluate our innovative real-time, reliable and robust system for ECG triggering during cardiac MR imaging. The project has four specific aims. The first three, aimed at developing an effective MR ECG triggering system, are: 1) to optimize the Phase I prototype MRI ECG data acquisition, fiberoptic transmission system; 2) to optimize, evaluate and test our adaptive noise cancellation methods to remove the RF and magnetic gradient artifacts that overwhelm ECG detection, and 3) to develop a "real-time" embedded computer ECG trigger system and integrate it into a cardiovascular MR imaging system. Our last specific aim is to clinically analyze and evaluate the effectiveness of our MRI ECG trigger system. Our preliminary results illustrate the effectiveness of our methods in reliably detecting the ECG during MR imaging. Our methods include generating a novel optimal ECG vector for detection, and applying effective adaptive noise cancellation methods to extract the ECG R-wave from RF and gradient artifacts. Additional preliminary data demonstrates the capability of our optical telemetry system to transmit the ECG from the magnet and mitigate against the MR artifacts which corrupt the ECG signal. During Phase II, we will evaluate the performance of our triggering system using normal human subjects and a recorded data base of ECG arrhythmias and other defects. Our approach should provide a reliable and robust ECG trigger with minimal delay from the onset of the R-wave. Such a trigger would minimize blurring artifacts from cardiac and respiratory motion and improve MR tagging studies.

描述（申请人提供）：磁共振成像（MRI）已成为心脏结构和功能定量评估的金标准。成像运动心肌的关键是一个可靠和强大的心电图信号，作为一个“触发器”，可以在整个心脏周期的特定阶段提供图像。磁场强度更强的磁体，更大的磁梯度旋转率，以及不断增加的磁梯度脉冲序列，如那些提供心脏灌注的脉冲序列，大大增加了触发的难度。此外，患有心脏疾病的人可能有异常的心电图。该二期项目的重点是研究、开发和临床评估我们创新的实时、可靠和强大的心脏MR成像过程中ECG触发系统。该项目有四个具体目标。前三项，旨在开发一个有效的磁共振心电触发系统，分别是：1)优化第一阶段原型MRI心电数据采集、光纤传输系统；2)优化、评估和测试我们的自适应降噪方法，以去除干扰心电检测的射频和磁梯度伪影；3)开发“实时”嵌入式计算机心电触发系统，并将其集成到心血管磁共振成像系统中。我们的最后一个具体目标是临床分析和评估我们的MRI心电图触发系统的有效性。我们的初步结果说明了我们的方法在磁共振成像过程中可靠地检测心电图的有效性。我们的方法包括生成一种新的最优心电矢量用于检测，并应用有效的自适应噪声消除方法从RF和梯度伪影中提取心电r波。额外的初步数据证明了我们的光学遥测系统从磁体传输心电信号的能力，并减轻了破坏心电信号的MR伪影。在II期，我们将使用正常受试者和记录心律失常和其他缺陷的数据库来评估我们的触发系统的性能。我们的方法应该提供一个可靠和健壮的ECG触发器，从r波开始的最小延迟。这样的触发将最大限度地减少心脏和呼吸运动产生的模糊伪影，并改善磁共振标记研究。