Free breathing cardiac MRI sequences

描述（由申请人提供）：本研究的目的是开发自由呼吸心脏磁共振成像，用于准确和快速评估心脏形态、心室功能、血流动力学和心肌表征。目前，临床心脏MRI是使用屏气2D采集方法进行的，通过多次重复屏气逐层成像心脏。这种屏气方法的局限性包括不适用于呼吸困难的患者，屏气问题的图像质量差，切片配准不良，空间分辨率和体积覆盖不充分。我们和其他人使用笔形束横膈膜导航仪开发了自由呼吸方法来解决这些屏气问题。然而，在临床实践中很少进行自由呼吸心脏MRI，部分原因是心脏导航序列尚未充分开发，横膈膜导航仪不能直接测量心脏运动，并且当前导航仪扫描时间过长。我们建议扩展和优化自由呼吸导航心脏MRI序列。心脏脂肪导航器将用于直接监测心脏的运动。使用同步多容积方法将提高导航器扫描效率。使用基于多线圈的并行成像将进一步缩短扫描时间。成功完成后，这项研究将导致快速准确的自由呼吸心脏MRI。在这个为期五年的研究项目中，我们将专注于开发两种类型的脉冲序列，心电图触发的分段序列（黑血快速自旋回波和心肌延迟增强）和电影序列（电影相位对比和电影稳态自由进动）的导航并行成像。这是我们实践中最常用的四种脉冲序列。因此，我们计划通过以下具体目标实现快速准确的自由呼吸心脏MRI的目标：1。为ECG触发的分段序列开发心脏脂肪导航器和集成导航器并行成像。2.为电影序列开发导航器并行成像。3.在一组心脏病患者中评价已开发的自由呼吸心脏MRI。该研究基金将使用导航方法和加速并行成像方法开发快速自由呼吸心脏MRI序列。它将克服目前屏气心脏MRI的局限性。这将使心脏MRI检查的受益范围扩大到屏气困难的患者。它将提高心脏MRI的空间分辨率、空间覆盖范围、时间分辨率和扫描速度。

DESCRIPTION (provided by applicant): The objective of this research is to develop free breathing cardiac magnetic resonance imaging for accurate and fast assessment of cardiac morphology, ventricular function, flow dynamics and myocardial characterization. Currently clinical cardiac MRI is performed using the breath-holding 2D acquisition approach, imaging the heart slice by slice through many repetitive breath-holds. The limitations of this breath-hold approach include inapplicability in dyspneic patients, poor image quality with problematic breath-holding, slice misregistration, indequate spatial resolution and volume coverage. The free breathing approach to address these breath-hold problems have been developed by us and others using the pencil beam diaphragm navigator. However, free breathing cardiac MRI is rarely performed in clincal practice, partly because cardiac navigator sequences have not been adequately developed, the diaphragm navigator does not measure heart motion directly, and current navigator scan time is too long. We propose to expand and optimize free breathing navigator cardiac MRI sequences. The cardiac fat navigator will be used to directly monitor motion of the heart. Navigator scan efficiency will be increased using the simultaneous mulitple volume approach. The scan time will be further shortened using multiple coil based parallel imaging. Upon successful completion, this research will lead to a fast and accurate free breathing cardiac MRI. In this five year research project, we will focus on developing navigator parallel imaging for two types of pulse sequences, eletrocardiogram-triggered segmented sequences (black blood fast spin echo and myocardial delayed enhancement) and cine sequences (cine phase contrast, and cine steady state free precession). These are the four most commonly used pulse sequences in our practice. Accordingly we plan to achieve the goal of fast accurate free breathing cardiac MRI through the following specific aims: 1. Develop cardiac fat navigator and integrated navigator parallel imaging for ECG-triggered segmented sequences. 2. Develop navigator parallel imaging for cine sequences. 3. Evaluate developed free breathing cardiac MRI in a cohort of cardiac patients. This research grant will develop fast free breathing cardiac MRI sequences using the navigator method and the accelerated parallel imaging method. It will overcome the limitation of current breath hold cardiac MRI. It will extend the benefit of cardiac MRI examination to patients with difficulty holding breath. It will improve the spatial resolution, spatial coverage, temporal resolution, and scan speed of cardiac MRI.