TRD2 - Ultrahigh Field Molecular Imaging and Spectroscopy

总结/摘要 本项目的主要目标是开发一个超高频磁共振成像平台 作为一个越来越敏感的分子成像平台，用于分子成像的可视化，表征， 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 信噪比和光谱色散提供了增加静磁场，同时克服其 通过开发新的系统解决方案、采集方法和重建， 战略布局该平台将在独特的10.5T全身MRI扫描仪上开发，并将利用 由16通道并行发射（pTx）系统提供的先进射频（RF）管理。三 我们将在本项目中采用特定的分子成像策略，每种策略都有特定的目标。在SA 1中，我们 将开发一个平台，用于UHF的集成和先进的多核应用，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31 P、23 Na或13 C）可以 可以在同一会话或同一扫描中使用，后者可以实现高级多核应用。这 当前系统上不存在该功能，并且该功能对于10.5T是强制性的。在SA 2中，我们将使用pTx RF 产生用于改进的光谱成像的新型加速空间光谱脉冲的脉冲设计方法 降低发射场灵敏度、B 0灵敏度和回波时间的研究。基于模型的重建 战略将使我们能够加快收购，同时提供更好的估计代谢物， 室特异性参数，例如T2和/或扩散，其与衰老和疾病两者相关。 在SA 3中，我们将使用动态RF匀场和RF脉冲设计策略来改善磁化 旋转框架松弛方法用于探测分子动力学的准备。读出和 还将探索重建策略以提高SNR效率并加快松弛速率 映射.最后，在SA 1和SA 3中，我们将探索超短回波时间成像的使用和优化 从短T2自旋捕获信号的方法，如当成像钠或当试图测量弛豫时 髓磷脂的速率特性。总的来说，这种分子成像平台的发展将提供无与伦比的 探测分子参数以通过分子动力学表征组织的功能和灵敏度， 功能代谢参数的空间分布和先进的多核研究。发达 技术将加强推动合作项目，重点是探索新的生物标志物，以诊断 疾病，监测进展并评估各种病理学（包括骨关节炎）的治疗反应， 多发性硬化症老年痴呆症和癌症虽然主要的重点是这些方法的实施， 10.5T的最高灵敏度增益，这些方法可以积极影响7 T系统，在某些情况下，甚至 低场

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.