Robust Cardiac Self-Gating For Fetal Cardiac MRI

描述（由申请人提供）：先天性心脏病（CHD）是北美最常见的先天性缺陷，影响千分之八的活产婴儿。产前诊断冠心病可以在出生前和出生前对患者进行更好的管理。在目前的临床实践中，超声检查心脏的解剖和功能以及通过瓣膜和大血管的血液流动通常用于诊断冠心病。然而，由于各种原因，超声波的使用在某些患者中受到限制。在这些情况下，胎儿心脏MRI是一种很有前途的替代成像方式，因为它具有良好的软组织对比和较少的辐射暴露。在过去的二十年中，心脏MRI技术的进步使心脏MRI在临床环境中得到了更广泛的应用。然而，由于各种原因，MRI用于胎儿心脏成像仍处于起步阶段。除了对胎儿成像的空间分辨率有更严格的要求外，一个主要的障碍是缺乏强大的心脏运动门控技术。在心脏MRI中，图像采集通常使用心电图（ECG）或外周脉冲信号与心脏周期同步，以最大限度地减少由心脏运动引起的伪影和图像模糊，或获得心脏相位分辨率图像。然而，这些信号根本无法用于胎儿MRI。因此，一个强大的心脏门控策略需要胎儿心脏MRI在临床上使用。该项目的总体目标是开发一种技术，可以可靠地提供用于胎儿心脏MRI的心脏运动自门控信号。在这个项目中，我们提出了几个技术创新，可用于常规获得可靠的胎儿心脏自门控信号。然后将对一组孕妇进行评估，这些孕妇因怀疑患有先天性心脏病而接受胎儿超声检查。

DESCRIPTION (provided by applicant): Congenital heart disease (CHD) is the most common congenital defect affecting eight per thousand live births in North America. Prenatal diagnosis of CHD allows for improved and better informed decisions on patient management before and after birth. In current clinical practices, an ultrasound examination of the anatomy and function of the heart as well as the blood flow through the valves and great vessels is usually used for diagnosis of CHD. However, the use of ultrasound is limited in certain patients due to various reasons. In these cases, fetal cardiac MRI is a promising alternative imaging modality due to its excellent soft tissue contrast and lack of radiation exposure. Advances in cardiac MRI technology in the last two decades have enabled more widespread use of cardiac MRI in the clinical setting. However, the use of MRI for fetal cardiac imaging remains in its infancy due to various reasons. Aside from the more stringent requirement on spatial resolution for fetal imaging, a major impediment is lack of a robust cardiac motion gating technology. In cardiac MRI, the image acquisition is typically synchronized to the cardiac cycle using either an electrocardiogram (ECG) or peripheral pulse signal to minimize the artifacts and image blurring resulting from cardiac motion or to obtain a cardiac phase resolved image. However, these signals are simply not available for fetal MRI. Therefore, a robust cardiac gating strategy is needed for fetal cardiac MRI to be used clinically. The overall goal of this project is to develop techniques that can reliably provide a cardiac motion self- gating signal for use in fetal cardiac MRI. In this project, we propose several technical innovations that can be used routinely to obtain reliable fetal cardiac self-gating signal. The developed strategies will then be evaluated on a cohort of pregnant women who are referred to fetal ultrasound for suspected congenital heart disease.