Motion-Robust Methods for Rapid Pediatric MRI without Sedation

项目总结/摘要 需要镇静是幼儿磁共振成像（MRI）的一个重要问题。这一挑战 因为在临床应用中使用的体积成像的典型长持续时间对于婴儿来说太长 小朋友们自愿留下来。如果没有麻醉，扫描过程中的运动会使图像失真， 诊断所需的关键特征。与呼吸相关的运动进一步降低图像质量，并且屏气可能会导致图像质量下降。 对小孩子来说不现实。该项目旨在消除大多数儿科MRI使用镇静剂， 新的采集和重建方法，可加速成像过程并跟踪和补偿运动。一 在没有任何镇静剂的情况下进行的儿科MRI范例将使临床MRI在幼儿中得到更广泛的应用。 其他好处包括更短，更便宜的检查，这是更容易安排没有麻醉师的支持。这些 与X射线计算机等替代方法相比， 断层扫描（CT），其由于其高辐射剂量而不具有吸引力。这种区别变得更加重要， 重复成像是必要的，例如对儿科癌症患者的实体瘤的监测。 用于体积成像的常规MRI数据采集依赖于"自旋扭曲"方法，需要数千甚至更少的时间。 根据所需的视场和空间分辨率，需要数万个读数来重建体积。在 总的来说，整个体积可能需要几分钟来采集，并且通常需要具有不同对比度的多个体积。 在典型的成像会话中规定。患者在此过程中的运动可能会扭曲或模糊重建，渲染 图像无法使用。呼吸门控技术可以减少呼吸相关运动的影响，但这种方法 不要延伸到患者运动。分散注意力、适应环境和父母的参与也能帮助幼儿行为规范 在扫描仪环境中合作，但获得幼儿诊断质量MRI的典型过程 在扫描期间保持镇静或部分镇静。 本方案融合了互补脉冲序列和图像重建算法的设计，引入了一种混合 解决了具有挑战性的运动快速成像问题。我们假设，结合可变密度的内部- 具有自导航运动补偿基于模型的重建（Aim 2）的左螺旋采集（Aim 1）将大大 减少扫描时间并充分减轻患者运动，以实现诊断有用的儿科临床成像， 任何镇静，并引入一个低风险的替代诊断和定期治疗监测的实体瘤， 婴幼儿（目标3）。

Project Summary/Abstract The need for sedation is a significant concern for magnetic resonance imaging (MRI) of young children. This challenge arises because the typically long durations of volumetric imaging used in clinical applications are too long for infants and young children to remain still voluntarily. Without anesthesia, the motion during a scan would distort images, obscuring critical features needed for diagnosis. Breathing-related motion further reduces image quality, and breath-holds may be unrealistic for young children. This project aims to eliminate the use of sedation from the majority of pediatric MRIs using novel acquisition and reconstruction methods that accelerate the imaging process and track and compensate for motion. A pediatric MRI paradigm performed without any sedation would enable broader application of clinical MRI in young children. Other benefits include a shorter, less costly exam, which is easier to schedule absent anesthesiologist support. These benefits should make MRI a more attractive option for pediatric imaging versus an alternative such as X-ray computed tomography (CT), which is unattractive due to its high radiation dose. This distinction becomes even more important when repeated imaging is necessary, such as the monitoring of solid tumors in pediatric cancer patients. Conventional MRI data acquisition for volumetric imaging relies on a “spin warp” approach, requiring thousands or even tens of thousands of readouts to reconstruct a volume, depending on the desired field of view and spatial resolution. In total, an entire volume can take several minutes to acquire, and multiple volumes with different contrasts are generally prescribed in a typical imaging session. Patient motion during this process can distort or blur the reconstruction, rendering the images unusable. Respiratory gating techniques can reduce the effects of breathing-related motion, but such methods do not extend to patient motion. Distraction, acclimation, and parental involvement also can help young children to behave cooperatively in the scanner environment, but the typical process for acquiring diagnostic-quality MRI of young children remains sedation or partial sedation during scanning. This proposal merges complementary pulse sequence and image reconstruction algorithm design to introduce a hybrid solution to the challenging problem of fast imaging with motion. We hypothesize that combining a variable-density inter- leaved spiral acquisition (Aim 1) with self-navigating motion-compensated model-based reconstruction (Aim 2) will greatly reduce scan times and mitigate patient motion sufficiently to enable diagnostically useful pediatric clinical imaging without any sedation, and introduce a low-risk alternative for the diagnosis and regular treatment monitoring of solid tumors in infants and young children (Aim 3).