4D Flow MRI-based assessment of atrial fibrillation

项目总结/摘要： 心房颤动（AF）是最常见的心律失常，估计占 大约占美国中风总数的15%。研究表明，这些患者的中风似乎 是由左心耳形成并进入大脑的外周血栓栓塞引起的。 抗凝剂已被证明在预防血栓栓塞形成方面非常有效，但 与更高的监测成本和出血风险相关。临床医生缺乏非侵入性诊断技术 可以可靠地评估心房血流动力学，目前的中风预防管理依赖于经验， 已被证明具有较低预测价值的确定风险评分。四维流动磁共振 成像提供时间分辨的三向速度编码，但目前受到长扫描时间的限制 分辨率不足。此外，在当前的MRI中没有考虑AF的逐搏变化 在多个心动周期内收集数据的协议。本项目旨在开发4D Flow MRI协议 它结合了改进的时空分辨率、减少的扫描时间和实时MRI， 综合评价房颤患者的心房血流动力学。我们将制定该方案，评估 重复性和准确性，并将该方案应用于AF患者和健康志愿者的小型研究。

Project Summary/abstract: Atrial fibrillation (AF) is the most common cardiac arrhythmia and estimated to account for approximately 15% of all strokes in the United States. Studies have shown that strokes in these patients seem to be caused by peripheral thromboembolisms which form in the left atrial appendage and travel to the brain. Anticoagulation has been shown to be highly effective at preventing thromboembolism formation, but is associated with greater monitoring costs and bleeding risks. Clinicians lack non-invasive diagnostic techniques that can reliably assess atrial hemodynamics, and current stroke prevention management relies on empirically determined risk scores that have been shown to have low predictive value. 4D flow magnetic resonance imaging provides time-resolved, three directional velocity encoding, but is currently limited by long scan times and inadequate resolution. In addition, the beat-to-beat variation of AF has not been considered in current MRI protocols that collect data over multiple cardiac cycles. This project aims to develop a 4D flow MRI protocol that incorporates improved temporal-spatial resolution, decreased scan time, and real-time MRI to more comprehensively assess atrial hemodynamics in AF patients. We will develop this protocol, assess repeatability and accuracy, and apply the protocol to a small study of AF patients and healthy volunteers.