Improved Motion Robust MRI of Children

项目摘要 磁共振成像（MRI）对于儿科护理至关重要。然而，患者运动 严重限制了我们在可能无法做出反应的幼儿中制作高质量图像的能力 以及口头指示和谁有困难保持仍然在扫描仪内。MRI期间的头部运动 破坏空间编码并导致数据丢失，在图像中产生一系列伪影， 诊断实用程序。因此，镇静和麻醉常规用于儿科人群;然而，这些 实践与严重的不良事件相关，并且非常耗时和昂贵， 管理。不幸的是，当前最先进的运动补偿技术既不快速也不准确 足以充分补偿不合作儿童的大而频繁的头部运动，或 需要外部硬件，这对于临床工作流程来说远非理想。在上一个资助期内，我们 在实现我们的总体目标，即改进运动稳健的儿科MRI方面取得了重大进展， 成功开发了一种新的利用自由感应衰减（FID）的无标记运动跟踪方法 导航仪和新算法，以产生诊断图像的小周期的无运动时间。的 根据向NIH的重新申请，提出的研究目标有两个方面：1）继续开发 并改进用于运动测量和校正的新型无标记技术， 大的、频繁的运动的存在，以及2）评估这些技术以提高质量， 不使用镇静和麻醉的儿科MRI的成功率。我们假设， FID导航仪运动测量的准确性，以及我们校正算法的范围和速度， 成功地补偿了图像中持续伪影的来源。为了实现这些宏伟目标， 我们建议在5年的援助期内实现以下具体目标：1）发展 并评估一个扩展的模型，该模型可以首次同时测量头部运动和诱发的 使用FID导航仪的磁场变化; 2）开发和评估一种新的自导航3D径向 增强重建采集，用于回顾性校正运动和感应磁场 和线圈灵敏度变化; 3）开发和评估预期的运动校正和动态匀场 利用实时运动和场测量来产生无伪影图像;以及4）应用和评估 这些高度创新的运动补偿技术用于对0-8岁的患者进行成像， 镇静剂本申请中提出的运动鲁棒成像技术可以容易地部署在 具有广泛可用的标准MRI硬件的临床环境，因此预计将具有快速的 目前通过MRI评估的无数儿科疾病和病症的翻译影响。的能力 在不使用镇静剂和麻醉剂的情况下对幼儿进行成像将大大减少时间、费用 以及利用MRI生成诊断上有用的图像所涉及的风险。

Project Summary Magnetic resonance imaging (MRI) is critically important for pediatric care. However, patient motion significantly limits our ability to produce high-quality images in young children who may be unable to respond well to verbal instructions and who have difficulty remaining still inside the scanner. Head motion during MRI disrupts spatial encoding and leads to data loss, generating a range of artifacts in the images, which hinders diagnostic utility. Thus, sedation and anesthesia are routinely used in pediatric populations; however, these practices are associated with severe adverse events and are extremely time-consuming and costly to administer. Unfortunately, current state-of-the-art motion compensation technologies are not fast or accurate enough to adequately compensate for large and frequent head movements in uncooperative children, or require external hardware, which is far from ideal for clinical workflow. Under the previous grant period, we made significant progress towards our overarching goal of improved motion-robust pediatric MRI by successfully developing a new markerless motion tracking approach utilizing free induction decay (FID) navigators and novel algorithms to generate diagnostic images from small periods of motion-free time. The goal of the research proposed under this renewed application to the NIH is two-fold: 1) to continue to develop and refine novel markerless technologies for motion measurement and correction to enable high-quality MRI in the presence of large, frequent motion and 2) to evaluate these technologies for improving the quality and success rate of pediatric MRI without the use of sedation and anesthesia. We hypothesize that improving the accuracy of FID navigator motion measurements, and the extent and speed of our correction algorithms, will successfully compensate for sources of persistent artifacts in the images. To achieve these ambitious goals, we propose to undertake the following Specific Aims over the 5-year period of requested support: 1) develop and evaluate an extended model that can, for the first time, simultaneously measure head motion and induced magnetic field changes using FID navigators; 2) develop and evaluate a novel self-navigated 3D radial acquisition with augmented reconstruction for retrospective correction of motion, and induced magnetic field and coil sensitivity variations; 3) develop and evaluate prospective motion correction and dynamic shimming utilizing real-time motion and field measurements to produce artifact-free images; and 4) apply and evaluate these highly innovative motion compensation techniques for imaging 0–8 year old patients without the use of sedation. The motion-robust imaging technologies proposed in this application can be easily deployed in clinical settings with widely-available, standard MRI hardware, and are therefore expected to have rapid translational impact for the countless pediatric diseases and disorders presently evaluated by MRI. The ability to image young children without the use of sedation and anesthesia will dramatically decrease the time, cost and risk involved in generating diagnostically useful images with MRI.