Motion and distortion robust diffusion weighted imaging sequences for pediatric patients

项目摘要 在儿童癫痫耐药发作患者中，手术切除是最有效的治疗方法。 选择。切除手术的目标是最大限度地切除癫痫灶，以实现癫痫的自由发作，同时 最大限度地减少对周围脑区的损害，避免手术后永久性的功能丧失。扩散 MRI可以在手术前对语言、运动技能和其他关键功能进行快速、非侵入性的标测 具有高空间分辨率的大脑区域。然而，过度的头部运动是一个主要的限制 在儿童脑局灶性病变患者中获得高质量的弥散磁共振成像通常有困难 在长扫描持续时间内保持静止。不幸的是，目前的回顾和前瞻性方法不能 充分补偿扩散磁共振成像中运动的复杂影响。因为回波平面成像(EPI)是 非常容易受到局部磁场变化的影响，运动引起的几何扭曲可能会导致 即使有准确的头部运动跟踪，重要大脑区域的潜在严重错误定位也是如此。这个 在这项应用于美国国立卫生研究院的研究中提出的总体目标是显著改善 弥散磁共振成像在儿童癫痫患者术前标测中的质量。我们正在提出一个解决方案 基于双回波EPI序列，这被证明可以产生高质量的切片级别失真图， 可用于校正与运动相关的伪影。我们将生成一条产生运动和变形的管道 利用在线重新采集和失真校正策略，在扫描仪上免费提供图像。我们 假设这种改进的扩散MRI采集策略将产生技术上有用的 儿童癫痫患者对切除手术的评估比之前认为的可能的比率更高。 为了实现这些雄心勃勃的目标，我们将实现以下具体目标：具体目标1：发展、 优化和评估用于切片级几何失真校正的双回波序列；具体 目标2：开发和评估一种新的预期运动矫正技术，该技术可以估计和评估 纠正每个位置的几何扭曲；具体目标3：开发和评估工具 扫描仪运动和失真校正、再采集和扩散参数估计.具体 目的4：运动和失真补偿技术在儿科DW-MRI中的应用与评价 癫痫手术候选人：如果成功，我们的项目将促进广泛的临床适应 弥散磁共振成像用于癫痫的术前定位，并使高分辨率扩散磁共振成像能够用于研究 对不合规患者群体的研究。

Project Summary In pediatric epilepsy patients with drug-resistant seizures, surgical resection is the most effective treatment option. The goal of resective surgery is to maximize removal of epileptic foci to attain seizure-freedom while minimizing damage to surrounding brain regions to avoid permanent post-surgical functional loss. Diffusion MRI enables rapid and non-invasive pre-surgical mapping of language, motor skills and other critical functional brain regions with high spatial resolution. However, excessive head motion presents a major limitation for acquiring high-quality diffusion MRI in pediatric patients with focal brain lesions, who usually have difficulty remaining still for long scan durations. Unfortunately, current retrospective and prospective approaches cannot adequately compensate for the complex effects of motion in diffusion MRI. As echo planar imaging (EPI) is highly susceptible to local magnetic field variations, motion-induced geometric distortions can lead to potentially significant mislocalization of important brain regions, even with accurate head motion tracking. The overarching goal of the research proposed under this application to the NIH is to dramatically improve the quality of diffusion MRI for pre-surgical mapping in pediatric epilepsy patients. We are proposing a solution based on a dual-echo EPI sequence, which was shown to produce high quality slice level distortion maps that can be used to correct motion related artifacts. We will generate a pipeline that produces motion and distortion free images on the scanner with the utilization of an online reacquisition and distortion correction strategy. We hypothesize that this improved diffusion MRI acquisition strategy will produce technically useful tractography in pediatric epilepsy patients evaluated for a resection surgery at a higher rate than previously thought possible. To achieve these ambitious goals, we will undertake the following specific aims: Specific Aim 1: Develop, optimize and evaluate a dual echo sequence for slice level geometric distortions correction; Specific Aim 2: Develop and evaluate a novel prospective motion correction technology that estimates and corrects geometric distortions at each position; Specific Aim 3: Develop and evaluate tools for on- scanner motion and distortion correction, reacquisition and diffusion parameter estimation; Specific Aim 4: Apply and evaluate motion and distortion compensation technologies in DW-MRI of pediatric candidates for epilepsy surgery: If successful, our project will facilitate widespread clinical adaptation of diffusion MRI for pre-surgical mapping in epilepsy, and enable high resolution diffusion MRI for research studies in incompliant patient populations.