Real-Time MRI Motion Correction System

描述（由申请人提供）：动机-运动仍然是MR研究中最常见的图像伪影之一。MRI的运动敏感性是众所周知的，并催生了许多优雅的导航技术。然而，这些方法是针对特定的MR采集而定制的，这些采集需要修改k空间轨迹或获取额外的MR数据，并且大多数方法无法纠正某些类型的运动，例如穿过平面的运动。此外，运动校正一直集中在特定的序列族，但目前还没有普遍适用的方法。某些患者群体，如儿科或老年患者，比其他人更有可能移动。在儿科成像中，麻醉是用来控制运动的，这大大增加了检查成本和患者风险。序列独立，自主和前瞻性运动校正系统可以大大提高图像质量，为广泛的磁共振检查。对于儿科成像，特别是，我们预计减少依赖麻醉来控制患者的运动。AIMS -我们将专注于三个独立的具体目标（并行进行并在4年内完成），我们认为相应的子目标对于建立技术/科学价值非常重要，并证明我们的实时自适应运动校正方法的拟议研发工作的可行性。具体来说，这些目标是：(1)开发和评估用于常规临床使用的线圈式核磁共振兼容跟踪设备；(2)将姿态跟踪融入实时MRI；(3)在志愿者和患者身上验证我们的实时运动矫正系统。方法-在目标1中，我们将改进基于计算机视觉的MR扫描仪内部姿态估计方法，并构建可用于临床常规检查的MR兼容线圈式姿态跟踪器。在目标2中，我们将专注于减少姿势变化发生和MR扫描仪对这些姿势变化的反应之间的延迟，并建立一个用于MR脉冲序列开发的软件库，该软件库允许人们在所有MR脉冲序列中实现实时运动校正。在Aim 3中，我们将对60名志愿者（30名成人和30名儿童）和120名患者（80名成人和40名儿童）对我们的系统进行全面评估。重要性——我们的技术的影响有几个方面。首先，它将通过减少由于运动伪影而导致质量受损的MR图像的数量来改善患者护理。特别是由于越来越依赖于MR图像作为诊断的主要手段，这将减少误诊的数量。其次，这项技术将大大提高核磁共振成像扫描仪的效率，从而有助于降低国家在成像方面的高额支出。最后，它将通过减少重复序列的需要来改善患者的舒适度，以及减少旨在保持患者静止的镇静的必要性。总的来说，这项技术将对MRI的临床实践和基础科学研究产生重大影响。

DESCRIPTION (provided by applicant): MOTIVATION - Motion remains one of the most frequent contributors to image artifacts in MR studies. The motion susceptibility of MRI is well-known and has spawned a number of elegant navigation techniques. These methods, however, are tailored to specific MR acquisitions that require modified k-space trajectories or the acquisition of additional MR data, and most are unable to correct certain types of motion, for example, through-plane motion. Moreover, motion correction has been focused on specific families of sequences, but no generally applicable approach currently exists. Certain patient populations, such as pediatric or geriatric patients, are more likely to move than others. In pediatric imaging, anesthesia is used to control motion, adding substantially to exam costs and patient risks. A sequence-independent, autonomous and prospective motion correction system could greatly improve image quality for a wide spectrum of MR examinations. For pediatric imaging, in particular, we anticipate reduced reliance on anesthesia to control patient motion. AIMS - We will be focusing on three independent specific aims (carried out in parallel and completed within 4 years), with corresponding subaims that we believe are important for establishing the technical/scientific merit and to demonstrate the feasibility of the proposed R&D efforts for our real-time adaptive motion correction approach. Specifically, these aims are: (1) to develop and evaluate a coil-mounted MR-compatible tracking device for routine clinical use; (2) to integrate pose tracking into real-time MRI; and (3) to validate our real-time motion correction system in volunteers and patients. METHODS -In Aim 1 we will improve the methods for computer-vision-based pose estimation inside an MR scanner and build an MR-compatible coil-mounted pose tracker that can be used in clinical routine examinations. In Aim 2 we will focus on reducing the latency between pose changes happening and the MR scanner reacting to these pose changes, and on building a software library for the MR pulse sequence development that allows one to implement real-time motion correction into all MR pulse sequences. In Aim 3 we will perform a thorough evaluation of our system on 60 volunteers (30 adults and 30 children) and 120 patients (80 adults and 40 children). SIGNIFICANCE - The impact of our technology has several facets. First, it will improve patient care by reducing the number of MR images with compromised quality because of motion artifacts. Especially because of the increasing reliance on MR Images as a primary means of diagnosis, this will reduce the number of misdiagnoses. Secondly, this technology will help to lower the high national spending on imaging by dramatically improving the efficiency of MRI scanners. Finally, it will improve patient comfort by reducing the need for repeat sequences, as well as reduce the necessity of sedation aimed at keeping the patient still. Overall, this technology will have a significant impact on MRI both in clinical practice and basic science research. PUBLIC HEALTH RELEVANCE: Synopsis Patient motion during an MRI exam can result in major degradation of image quality and decreased efficiency in a large portion of the 40 million MRI procedures performed annually. This is not only of increasing concern due to the aging population and its associated diseases, but also in children and patients who are simply too sick to remain still during an exam. This proposal aims to build an optical tracking system and methods to adapt MRI pulse sequences to changes in patient pose in real time. The project leverages on previous work from an R21 project in which a prototype system was successfully built. Specifically, the aims are to (i) introduce innovative improvements to the existing prototype, making the system suitable for use in clinical routine, (ii) modify the optical tracking system to be compatible with multiple MR sequences, and (iii) perform clinical evaluation. Our real-time technique is a unique and innovative solution that will improve MRI image quality and thus patient care, and will address the escalating burden of imaging costs on the health care system.