TRD2 - Ultrahigh Field Molecular Imaging and Spectroscopy

摘要/摘要 该项目的主要目标是开发一种超高场磁共振成像(MRI)平台 分子成像作为一种日益灵敏的分子成像平台，用于可视化、表征和 在分子和细胞水平上测量生物过程。我们将认识到增加的好处 由增强的静磁场提供的信噪比和频谱色散，同时克服了其 通过开发新的系统解决方案、获取方法和重建而面临的多重挑战 战略。该平台将在独特的10.5T全身核磁共振扫描仪上开发，并将利用 由16通道并行传输(PTX)系统提供的高级射频(RF)管理。三 我们将在这个项目中追求特定的分子成像策略，每个策略都有一个特定的目标。在SA1，我们 将在超高频开发一个集成和先进的多核应用平台，其中质子(1H) 通道可以使用PTX更有效地传输，并且单个x核通道(即31P、23Na或13C)可以 可在同一会话或同一扫描中使用，后者支持高级多核应用程序。这 当前系统上不存在该功能，并且10.5T必须具备该功能。在SA2中，我们将使用PTX RF 产生用于改进光谱成像的新型加速空间光谱脉冲的脉冲设计方法 研究降低了发射场灵敏度、B0灵敏度和回声时间。基于模型的重建 然后，战略将允许我们加速收购，同时提供更好的代谢物估计和 特定间隔，与衰老和疾病相关的参数，如T2和/或弥散。 在SA3中，我们将使用动态RF垫片和RF脉冲设计策略来提高磁化强度 用于分子动力学探测的旋转标架松弛方法的准备。读出和 还将探索重建策略，以提高SNR效率和加快松弛速率 映射。最后，在SA1和SA3中，我们将探讨超短回波时间成像的使用和优化 捕捉短T2自旋信号的方法，如成像钠或试图测量松弛时 髓磷脂的速率特性。总之，这一分子成像平台的发展将提供无与伦比的 功能性和敏感度探测分子参数以通过分子动力学表征组织， 功能代谢参数的空间分布和先进的多核研究。已开发的 技术将加强推动合作项目，这些项目专注于探索新的生物标记物来诊断 疾病，监测进展和评估各种病理学的治疗反应，包括骨关节炎， 多发性硬化症、阿尔茨海默氏症和癌症。虽然主要关注的是这些方法在 10.5T为了获得最高的灵敏度增益，这些方法可以对7T系统产生积极影响，在某些情况下甚至 地势较低。

SUMMARY / ABSTRACT The main goal of this project is to develop an ultrahigh field (UHF) magnetic resonance imaging (MRI) platform for molecular imaging as an increasingly sensitive molecular imaging platform to visualize, characterize, and measure biological processes at the molecular and cellular levels. We will realize the advantages of increases signal-to-noise ratio and spectral dispersion afforded by increased static magnetic fields while overcoming its multiple challenges through the development of novel system solutions, acquisition methods and reconstruction strategies. This platform will be developed on a unique 10.5T whole body MRI scanner and will make use of advanced radiofrequency (RF) management afforded by a 16 channel parallel transmit (pTx) system. Three specific molecular imaging strategies we will pursued in this project, each detailed in a specific aim. In SA1, we will develop a platform for integrated and advanced multinuclear applications at UHF where the proton (1H) channel can transmit more efficiently using pTx and the single x-nuclei channel (i.e. 31P, 23Na, or 13C) can either be used within the same session or the same scan, the later enabling advanced multinuclear applications. This functionality currently does not exist on current systems and is mandatory for 10.5T. In SA2, we will use pTx RF pulse design methods to create novel accelerated spatial-spectral pulses for improved spectroscopic imaging studies with reduced transmit field sensitivity, B0 sensitivity and echo times. Model-based reconstruction strategies will then allow us accelerate the acquisitions while providing improved estimates of metabolite and compartment specific, parameters such as T2 and/or diffusion which are correlated with both aging and disease. In SA3, we will use dynamic RF shimming and RF pulse design strategies to improve the magnetization preparation for rotating frame relaxation methods used to probe molecular dynamics. Readout and reconstruction strategies will also be explored to improve SNR efficiency and to accelerate relaxation rate mapping. Finally in both SA1 and SA3 we will explore the use and optimization of ultrashort echo time imaging methods to capture signals from short T2 spins as when imaging sodium or when trying to measure the relaxation rate properties of myelin. In total, the development of this molecular imaging platform will provide unparalleled functionality and sensitivity to probe molecular parameters to characterize tissue through molecular dynamics, spatial distributions of functional metabolic parameters and advanced multinuclear studies. The developed technologies will enhance the driving collaborative projects which focus on exploring new biomarkers to diagnose disease, monitor progression and evaluate treatment response in a variety of pathologies including osteoarthritis, multiple sclerosis, Alzheimer's and cancer. While the main focus is on the implementation of these methods at 10.5T for the highest sensitivity gains, the methods can positively impact 7T systems and in some cases even lower fields.