Motion and distortion robust diffusion weighted imaging sequences for pediatric patients

项目摘要 在小儿癫痫患者出现耐药性癫痫发作时，手术切除是最有效的治疗方法 选项.切除性手术的目的是最大限度地切除癫痫灶，以达到无癫痫， 最大限度地减少对周围脑区的损伤，以避免术后永久性功能丧失。扩散 MRI能够快速、无创地对语言、运动技能和其他关键功能进行术前定位， 高空间分辨率的大脑区域。然而，过度的头部运动对 在患有局灶性脑病变的儿科患者中获得高质量的弥散MRI，这些患者通常难以 在长扫描持续时间内保持静止。不幸的是，目前的回顾性和前瞻性方法不能 充分补偿扩散MRI中运动的复杂影响。由于回波平面成像（EPI）是 由于对局部磁场变化高度敏感，运动引起的几何畸变可导致 重要的大脑区域的潜在显著的错误定位，即使具有精确的头部运动跟踪。的 在向NIH提交的这项申请中提出的研究的总体目标是大大改善 小儿癫痫患者术前磁共振弥散成像的质量我们提出了一个解决方案 基于双回波EPI序列，该序列被证明可以产生高质量的切片级失真图， 可以用于校正与运动相关的伪像。我们将生成一个流水线，产生运动和失真 利用在线重新获取和失真校正策略，在扫描仪上获得免费图像。我们 假设这种改进的弥散MRI采集策略将产生技术上有用的纤维束成像， 儿童癫痫患者接受切除手术的比率高于以前认为的可能性。 为了实现这些宏伟目标，我们将致力于以下具体目标：具体目标1：发展， 优化和评估双回波序列，以进行切片级几何失真校正;具体 目标2：开发和评估一种新的前瞻性运动校正技术， 在每个位置校正几何失真;具体目标3：开发和评估工具， 扫描仪运动和失真校正、重新获取和扩散参数估计;特定 目的4：运动和失真补偿技术在儿童DW-MRI中的应用和评价 癫痫手术的候选人：如果成功，我们的项目将促进广泛的临床适应， 扩散MRI用于癫痫的术前标测，并使高分辨率扩散MRI用于研究 在不依从的患者人群中进行的研究。

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.