Novel Diffusion MRI in Early Psychosis

摘要 我们的目标是提供新颖、临床可行和精确的扩散磁共振成像(DMRI)技术- 研究早期精神病活体人脑细胞微结构的术语。精神错乱- 订单是一种毁灭性的大脑疾病，包括一系列症状，如妄想、幻觉和 思维障碍。更好地了解精神病的病因可以改善诊断和治疗 治疗。Dmri是一种非侵入性的成像方法，它已经识别出了独特的微结构异常。 精神错乱。然而，由于许多病理过程被认为在精神病中共存，因此有一种 需要从数字磁共振成像中得出更具体的措施。 目前最先进的dMRI使用一种称为 单扩散编码。我们提出了q空间轨迹成像(Qti)，这是一种新的动态dmri方法。 在采集过程中更改测量方向，以更好地表征水的真实复杂性 分子运动。我们提出的新的QTI序列允许测量微结构特性 用今天的扫描方法是看不见的活体人脑。这些微观结构特性 以大小(CMD)、形状(C？)和方向(CC)的可变性来数学表示，提取 来自代表不同神经元组织微环境的混合模型，例如神经突起、细胞 结构域和胞外空间。 为了实现我们的目标，我们提出了以下三个目标。在目标1中，我们将发展实验基础 用于新的核磁共振成像。我们将研究QTI方法，以更好地表征重要的病理特征 被认为是精神病患者。我们将扩展QTI框架，使微结构模型和属性能够 明确说明了受限、非高斯和随时间变化的扩散。它的成功终点是 AIM将为提取与精神病相关的新的微观结构特征提供方法和模型 来自QTI。在目标2中，我们将开发新的dMRI序列和标准。我们建议开发强大的和 快速QTI脉冲序列和扫描协议，以DICOM表示采集参数。这个 这一目标的成功终点将是新颖、强大和快速的收购(不到15分钟)，使QTI能够 临床研究。在目标3中，我们建议在24例早期精神病患者中研究基于QTI的微结构测量。 TITS和24名匹配的对照组，以理清精神病中共存的病理，如神经退行性变- 运动性和神经炎性过程。 我们预期在拟议项目成功完成后，我们将开发出新的dMRI以 为研究活体人脑的细胞微结构提供了更高的敏感性和特异性。

Abstract Our goal is to provide novel, clinically feasible, and precise diffusion magnetic resonance imaging (dMRI) tech- nologies for investigation of the in-vivo human brain's cellular microstructure in early psychosis. Psychotic dis- orders are devastating brain diseases that include a range of symptoms such as delusions, hallucinations, and thought disorder. A better understanding of the etiology of psychosis can lead to improved diagnosis and treatment. dMRI is a noninvasive imaging method that has identified unique microstructural abnormalities in psychosis. However, as many pathological processes have been proposed to co-exist in psychosis, there is a need for more specific measures derived from dMRI. Current state-of-the-art dMRI encodes (measures) diffusion along a single direction using a technique called single diffusion encoding. We propose q-space trajectory imaging (QTI), a new dMRI method that dynamically changes the measurement orientation during acquisition to better characterize the true complexity of water molecule motion. The novel QTI sequences that we propose allow measurement of microstructural properties of the in-vivo human brain that are invisible using today's scanning methods. These microstructural properties are mathematically expressed in terms of variability in size (CMD), shape (Cµ), and orientation (Cc), extracted from a model representing a mixture of distinct neuronal tissue microenvironments, such as neurites, cellular domains and extracellular spaces. To achieve our goals we propose the following three aims. In Aim 1, we will develop experimental foundations for novel dMRI. We will investigate QTI methodologies to better characterize important pathological features expected in psychosis. We will extend the QTI framework to enable microstructural models and properties that explicitly account for restricted, non-Gaussian, and time-dependent diffusion. The successful endpoint of this aim will provide measures and models for the extraction of new microstructural properties related to psychosis from QTI. In Aim 2, we will develop novel dMRI sequences and standards. We propose to develop robust and fast QTI pulse sequences and scan protocols, with representation of the acquisition parameters in DICOM. The successful endpoint of this aim will be novel, robust, and fast acquisitions (under 15 minutes), enabling QTI for clinical studies. In Aim 3, we propose to study QTI-based microstructure measures in 24 early psychosis pa- tients and 24 matched controls to disentangle pathologies that co-exist in psychosis, such as neurodegenera- tive and neuroinflammatory processes. We expect that upon successful completion of the proposed project, we will have developed novel dMRI to provide increased sensitivity and specificity for the study of the in-vivo human brain's cellular microstructure.