Improved Myocardial Perfusion Assessment using High-Performance Low-Field MRI

项目摘要 本项目将开发和评估一种用于心肌灌注评估的改进工具，该工具简单， 鲁棒，并提供改进的分辨心肌层的能力。我们将通过利用一本小说 高性能低场（HPLF）磁共振成像（MRI）平台。依据：冠状动脉 冠心病（CAD）是美国的主要死因。心肌灌注成像是一种必不可少的 患者管理和诊断工具。心肌首过灌注（FPP）MRI是目前最主要的非心肌灌注成像技术。 但是，它受到成像伪影、有限覆盖和有限的 分辨心肌层的能力。解决这些问题将提高我们检测、管理和 了解CAD创新：我们预计MRI FPP将从HPLF MRI平台中受益匪浅，因为它 承诺大大减少伪影，并有机会改善空间覆盖范围，空间分辨率， 时间分辨率该项目将利用在0.55特斯拉下运行的HPLF系统，以实现改进的 心肌灌注评估，与今天在1.5特斯拉和3特斯拉系统上的可能性相比。我们 还将应用新的实时成像技术，以避免对心电图（ECG）信号的需要。 方法：我们将开发0.55T全心脏MRI FPP，使用两种对比剂生成序列组合 使用螺旋堆叠（SOS）采集-一种使用ECG门控和饱和度恢复准备，另一种 回顾性地识别稳定期的非门控方法。SOS采样模式将进行优化， 心肌灌注测量的CNR、边界清晰度和精度。实现了空间覆盖， 空间分辨率、时间分辨率和SNR/CNR将使用体模，10个志愿者扫描， 和10个病人扫描然后，将在具有已知HPLF的患者队列（N=20）中测试优化的HPLF方法。 非透壁性瘢痕，并与标准3 T多层MRI FPP进行比较，以在技术上验证 检测低灌注的非透壁模式，并评估相对伪影水平。更广泛的影响： 该项目将提供0.55T MRI FPP，与现有技术相比， 在常规MRI场强下可能发生。从长远来看，这种方法可以改善诊断， CAD的评价本项目开发的成像方法将广泛适用于心脏和动态 在HPLF MRI平台上成像。

PROJECT SUMMARY This project will develop and evaluate an improved tool for myocardial perfusion assessment, that will be simple, robust, and provide improved ability to resolve myocardial layers. We will achieve this by leveraging a novel high-performance low-field (HPLF) magnetic resonance imaging (MRI) platform. Rationale: Coronary artery disease (CAD) is the leading cause of death in the United States. Myocardial perfusion imaging is an essential tool in patient management, and prognostication. Myocardial first-pass perfusion (FPP) MRI is the leading non- invasive and radiation-free technique; however, it suffers from imaging artifact, limited coverage, and limited ability to resolve myocardial layers. Resolving these issues will improve our ability to detect, manage, and understand CAD. Innovation: We expect MRI FPP to greatly benefit from the HPLF MRI platform, because it promises substantially reduced artifacts, and opportunities for improved spatial coverage, spatial resolution, and temporal resolution. This project will leverage an HPLF system operating at 0.55 Tesla, to achieve improved myocardial perfusion assessments, compared to what is possible today on 1.5 Tesla and 3 Tesla systems. We will also apply novel real-time imaging techniques to avoid the need for an electrocardiogram (ECG) signal. Approach: We will develop 0.55T whole-heart MRI FPP using two contrast generation sequences in combination with stack-of-spiral (SOS) acquisition—one that uses ECG-gating and saturation recovery preparation, and one ungated approach that retrospectively identifies stable phases. The SOS sampling pattern will be optimized for CNR, boundary sharpness, and precision of myocardial perfusion measurements. Achieved spatial coverage, spatial resolution, temporal resolution, and SNR/CNR will be measured using phantoms, 10 volunteer scans, and 10 patient scans. The optimized HPLF methods will then be tested in a cohort of patients (N=20) with known non-transmural scar, and compared with standard 3T multi-slice MRI FPP, to technically validate the ability to detect non-transmural patterns of hypoperfusion, and to evaluate relative artifact levels. Broader Impact: This project will provide 0.55T MRI FPP with reduced artifact and improved spatial information, compared to what is possible at conventional MRI field strengths. In the long term, this approach could improve the diagnosis and assessment of CAD. The imaging methods developed in this project will broadly benefit cardiac and dynamic imaging on HPLF MRI platforms.