Multiband ASL for Neurodevelopment Study

项目总结/摘要 从童年到青春期和青年期之间的发展时期， 潜力和脆弱性的结合一些潜在的终身行为和情感问题 在这个关键时期出现，包括酒精和非法药物的使用，危险行为，以及第一个 情绪障碍的迹象。了解典型开发的详细模式是很重要的， 可以尽早发现和纠正改动。作为一种完全非侵入性的， 定量成像方法，动脉自旋标记（ASL）灌注MRI正日益受到 被认为是两个健康人群中大脑功能发育的重要生物标志物 和神经发育障碍。然而，要使ASL成为一个 研究神经发育的有效工具，包括：1）约4x 4x 4 mm 3的粗略空间分辨率， 2)分段3D采集对头部运动的敏感性，以及3）潜在的混杂效应 使用单次标记后延迟（PLD）扫描的动脉通过时间的年龄依赖性变化。 同时多切片（SMS）或多波段（MB）是一种新的加速成像技术， 同时激励多个切片并利用并行成像技术恢复每个切片。 MB与ASL结合的初步研究表明，MB可以减少标记的T1弛豫， 与标准2D ASL相比，提高了空间覆盖和/或分辨率。MB成像可以 还克服了3D ASL采集在头部运动和空间模糊方面的限制。 然而，现有MB ASL的信噪比（SNR）不如3D ASL。这个项目 基于我们实验室最近的两项创新：1）受限切片依赖（CSD）背景 抑制（BS）技术，将2D MB pCASL的SNR提高到与3D MB pCASL相当 pCASL;以及2）具有2D CAIPIRINHA加速度的单次激发3D GRASE pCASL方法， 提高了3D pCASL的成像速度。本R 01项目的目标是开发和评估 先进的MB pCASL协议，能够提供各向同性2 mm或更高的空间分辨率， 更高的头部运动阻力和多延迟能力， 儿科人群。一种基于卷积神经网络的多时延去噪算法 将进一步开发MB pCASL。开发的MB pCASL协议套件和后 处理算法将在40名发育正常的儿童和青少年中进行评估。的 该R 01项目的成功完成将导致一个强大的多延迟MB pCASL协议， 作为神经发育研究和儿科临床护理潜在生物标志物非常有价值。 为了最大限度地发挥科学和临床影响，我们将继续传播脉冲序列， 相关的后处理软件，就像我们在过去十年中所做的那样。

Project Summary/Abstract The developmental period between childhood to adolescence and young adulthood is marked by a mix of potential and vulnerability. A number of potentially life-long behavioral and emotional problems emerge during this critical period, including alcohol and illicit drug use, risky behaviors, and the first signs of emotional disorders. It is important to understand detailed patterns of typical development, so alterations can be identified and rectified as early as possible. As an entirely noninvasive and quantitative imaging method, arterial spin labeled (ASL) perfusion MRI is increasingly being recognized as an important biomarker for functional brain development in both healthy populations and neurodevelopmental disorders. However, there remain significant challenges for making ASL an impactful tool in studying neurodevelopment, including: 1) a coarse spatial resolution of ~4x4x4mm3, 2) susceptibility to head motion with segmented 3D acquisitions, and 3) potential confounding effects of age dependent variations in arterial transit time using a single post-labeling delay (PLD) scan. Simultaneous multi-slice (SMS) or multiband (MB) is a new accelerated imaging technology that simultaneously excites multiple slices and recovers each slice with parallel imaging techniques. Preliminary studies combining MB with ASL showed that MB can reduce T1 relaxation of the label, improve spatial coverage and/or resolution compared to those of standard 2D ASL. MB imaging may also overcome the limitation of 3D ASL acquisitions in terms of head motion and spatial blurring. However, the signal-to-noise ratio (SNR) of existing MB ASL is inferior to that of 3D ASL. This project builds on two recent innovations from our lab: 1) a constrained slice-dependent (CSD) background suppression (BS) technique that improves the SNR of 2D MB pCASL to be comparable to that of 3D pCASL; and 2) a single-shot 3D GRASE pCASL method with 2D CAIPIRINHA accelerations that improves the imaging speed of 3D pCASL. The goal of this R01 project is to develop and evaluate cutting-edge MB pCASL protocols that are able to offer a high spatial resolution of isotropic 2mm or higher, resistance to head motion and multi-delay capability for accurate perfusion quantification in pediatric populations. A convolutional neural network (CNN) based denoising algorithm for multi-delay MB pCASL will be further developed. The developed suite of MB pCASL protocol and post- processing algorithms will be evaluated in 40 typically developing children and adolescents. The successful completion of this R01 project will lead to a robust multi-delay MB pCASL protocol that is highly valuable as potential biomarker for both neurodevelopment research and pediatric clinical care. To maximize the scientific and clinical impact, we will continue disseminating the pulse sequence and associated post-processing software as we have been doing in the past decade.