Real-Time MRI Motion Correction System

描述（由申请人提供）：动机-运动仍然是MR研究中图像伪影的最常见因素之一。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，这些方法被定制为需要修改的k空间轨迹或采集附加MR数据的特定MR采集，并且大多数不能校正某些类型的运动，例如，通过平面运动。某些患者人群，如儿科或老年患者，比其他患者更容易移动。在儿科成像中，麻醉用于控制运动，大大增加了检查成本和患者风险。序列独立、自主和前瞻性的运动校正系统可以极大地提高广泛的MR检查的图像质量。特别是对于儿科成像，我们预计减少对麻醉的依赖，以控制患者的运动。AIMS -该项目旨在探索使用替代MRI运动补偿方法的可能性，使用患者位置的连续光学监测和MR扫描仪3D坐标系的准实时更新。因此，采集跟随患者头部的运动，提供几乎没有运动伪影和没有自旋历史伪影的MR扫描。这种方法需要开发和校准MR兼容的光学位置捕获系统（目标1），该系统可用于不断更新扫描仪的参考坐标系（目标2）。最后，有必要在志愿者身上测试新系统，以评估图像质量相对于传统扫描或基于导航仪的方法的改进（目标3）。方法-将开发一种MR兼容的光学位置跟踪设备，并安装到常见的头部线圈上。该器械将MR系统的参考系锁定到由患者头部位置定义的参考系。因此，当患者发生运动时，MR系统将更新其RF激励、梯度和数据接收，以与该运动保持同步。在2年内，将招募健康儿童（n=38）和成人（n=22），以比较传统MR和运动补偿MR，同时受试者在4个预定义的严重程度水平下进行运动。意义-该项目的成功将显著改善在存在运动的情况下进行的MR检查，因此将使大多数患者人群受益。然而，我们预计在儿科和老年患者中，使用运动补偿MR的优势将最大。这项研究工作的积极成果也将通过减少总体扫描时间或提高图像的诊断能力间接影响患者。我们有信心在未来的研究中表明，通过使用我们的方法，可以显着减少儿科扫描对麻醉的依赖。MR成像不断开发新的方法，以最大限度地减少或消除降低图像质量和增加患者检查时间的运动误差。该项目开发了一种基于光学运动检测系统的独特方法，该系统将安装在MRI头部线圈上。光学系统将跟踪头部位置;在整个图像采集时间内校正运动;提高诊断图像质量;并减少甚至消除由于患者头部运动而需要重复研究。

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. 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 - This project aims to explore the potential to use an alternative MRI motion compensation approach, using continuous optical monitoring of patient position and updating of the MR scanner's 3D coordinate system in quasi real-time. Acquisition thus follows the movement of the patients head, providing MR scans virtually free from motion artifacts and without spin history artifacts. This approach will require the development and calibration of an MR compatible optical position capture system (Aim 1), which can be used to continually update the scanner's reference coordinate system (Aim 2). Finally, testing the new system on volunteers is necessary to assess the improvements in image quality over conventional scanning or navigator- based methods (Aim 3). METHODS - An MR-compatible optical position tracking device will be developed and mounted to common head coils. This device will lock the MR system's frame of reference to that defined by the position of the patient's head. Therefore, when patient motion occurs, the MR system will update its RF excitation, gradients, and data reception to keep pace with this motion. Over 2 years, healthy children (n=38) and adults (n=22) will be enrolled to compare conventional MR and motion-compensated MR while subjects perform movements at four predefined levels of severity. SIGNIFICANCE - The success of this project will significantly improve MR exams conducted in the presence of motion and will therefore benefit most patient populations. However, we expect that in pediatric and geriatric patients the advantages from using motion-compensated MR will be greatest. A positive outcome of this research effort will also affect patients indirectly by reducing the overall scan time or improving diagnostic capacity of the images. We are confident to show in future studies that, by using our approach, the dependence upon anesthesia in pediatric scanning can be significantly reduced. MR imaging continues to develop new approaches to minimize or eliminate motion errors that decrease image quality and increase patient exam time. This project develops a unique approach based on an optical motion detecting system that will be mounted on an MRI head coil. The optical system will track head position; correct for motion throughout image acquisition time; result in improved diagnostic image quality; and reduce, or even eliminate, the need for repeat studies due to patient head motion.