Motion-immune neuro and body MRI for challenging patient populations

描述(由申请人提供)：我们提出了一项计划，旨在开发和整合新的策略，以有效消除与运动相关的伪影，这是 为儿童、震颤主导型帕金森氏症患者和重病患者等具有挑战性的患者群体实现高质量的临床MRI。我们的项目预计将在多个临床领域立即产生重大影响。例如，1)对于腹部磁共振成像，所提出的方法即使在呼吸频率随时间显著变化的情况下也能够自由呼吸地获取高质量和高分辨率的MRI数据；2)对于神经MRI，我们的策略使得即使在受试者(例如帕金森患者)有持续的扫描内头部震颤时也能够实现高质量的成像。提出的运动免疫核磁共振策略是新颖的，在许多方面优于现有的方法。首先，我们的运动伪影校正技术可以更有效地处理非线性和局部运动(例如，在自由呼吸的腹部MRI中)，这是现有方法的局限性，这些方法依赖低分辨率导航回波信号或基于外部非MRI的运动测量(例如，使用红外传感器)。其次，我们的方法可以解决不同时间尺度的运动相关伪影(例如，从~3赫兹头部抖动到不频繁的扫描内移动)，这些伪影可能不总是通过依赖实时系统更新的方法来校正(例如，在1或2个TR之后动态改变切片位置)。第三，我们的方法既可以应用于笛卡尔成像脉冲序列，也可以应用于非笛卡尔成像脉冲序列，因此可以比仅适用于非笛卡尔成像的方法(例如，径向采样；螺旋桨成像)更容易和更快地转换到各种临床应用中。第四，我们的集成技术可以同时有效地处理多种形式的运动相关伪影，从多次激发扩散加权成像中的相位误差到大规模位置变化导致的信号损失。我们的运动免疫磁共振成像是通过独特地集成和优化两种新的方法来实现的：1)基于多路敏感编码的混叠伪影去除(MUSE)；2)基于重复k-t亚采样和伪影最小化的运动免疫结构MRI(REKAM)。我们计划建立运动免疫核磁共振方法，并在健康志愿者和两个具有挑战性的人群中评估所开发的方法：未服用镇静剂的儿童和震颤主导型帕金森患者。

DESCRIPTION (provided by applicant): Here we propose a plan to develop and integrate novel strategies to effectively eliminate motion-related artifact, which is the major bottleneck in achieving high-quality clinical MRI for challenging patient populations such as children, tremor-dominant Parkinson's patients and seriously ill patients among others. The impact of our project is expected to be immediate and significant across multiple clinical areas. For example, 1) for abdominal MR imaging, the proposed methods enable free-breathing data acquisition of high-quality and high- resolution MRI even when the respiratory frequency changes significantly over time; 2) for neuro MRI, our strategies make it possible to achieve high-quality imaging even when subjects have continual intra-scan head tremor (e.g., Parkinson's patients). The proposed motion-immune MRI strategies are novel, and superior to existing approaches in multiple ways. First, our motion artifact correction technique can more effectively address nonlinear and local motions (e.g., in free-breathing abdominal MRI), which have been limitations for existing methods that rely on either low-resolution navigator echo signals or external non-MRI based motion measurement (e.g., with infra-red sensors). Second, our method can address motion-related artifacts of different time scales (e.g., ranging from ~ 3 Hz head tremor to infrequent intra-scan movement), which may not always be corrected by methods that rely on real-time system updating (e.g., dynamically changing the slice location after 1 or 2 TRs). Third, our approach can be applied to both Cartesian and non-Cartesian imaging pulse sequences, and thus can be translated to various clinical applications more easily and quickly than methods only applicable to non-Cartesian imaging (e.g., radial-sampling; PROPELLER imaging). Fourth, our integrated technique can simultaneously and effectively address multiple forms of motion-related artifacts, ranging from phase errors in multi-shot diffusion-weighted imaging to signal loss due to large-scale position changes. Our motion-immune MRI is achieved through uniquely integrating and optimizing two novel approaches: 1) aliasing-artifact removal with multiplexed sensitivity encoding (MUSE), and 2) motion-immune structural MRI based on repeated k-t-subsampling and artifact-minimization (REKAM). We plan to build motion-immune MRI methods, and assess the developed methods in healthy volunteers and two challenging populations: un-sedated children and tremor-dominant Parkinson's patients.