Free breathing cardiac MRI sequences

描述（由申请人提供）：本研究的目的是发展自由呼吸心脏磁共振成像，以准确快速地评估心脏形态，心室功能，血流动力学和心肌特征。目前，临床心脏MRI采用屏气二维采集方法，通过多次重复屏气对心脏切片进行成像。这种屏气方法的局限性包括：不适用于呼吸困难的患者，图像质量差导致屏气问题，切片配准错误，空间分辨率和体积覆盖不足。自由呼吸的方法来解决这些屏气问题已经由我们和其他人使用铅笔束隔膜导航器开发。然而，自由呼吸心脏MRI在临床实践中很少进行，部分原因是心脏导航序列尚未充分开发，隔膜导航不能直接测量心脏运动，并且目前的导航扫描时间太长。我们建议扩展和优化自由呼吸导航心脏MRI序列。心脏脂肪导航仪将用于直接监测心脏的运动。使用同时多体积方法，Navigator扫描效率将得到提高。使用基于多线圈的并行成像将进一步缩短扫描时间。一旦成功完成，这项研究将导致快速和准确的自由呼吸心脏MRI。在这个为期五年的研究项目中，我们将重点开发两种脉冲序列的导航并行成像，即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）。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来实现快速准确的自由呼吸心脏MRI的目标：开发心脏脂肪导航仪和集成导航仪并行成像，用于ecg触发的分段序列。2. 开发导航并行成像的电影序列。3. 评估一组心脏病患者的自由呼吸心脏MRI。本研究资助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。它将克服目前憋气心脏MRI的局限性。它将心脏MRI检查的益处扩展到呼吸困难的患者。提高心脏MRI的空间分辨率、空间覆盖、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.