Dynamic Nuclear Polarization of Aerosols - A Novel Approach for Imaging Water Vapor and Enabling Lung Imaging

项目摘要 通过成像检测和表征肺部疾病及其对气道的影响是极其重要的。 由于组织密度低而具有挑战性。很少有选择来描述微观环境中的变化， 哮喘、肺炎、支气管炎、新冠肺炎等疾病中的空气进入和组织变化的特性， 慢性阻塞性肺疾病使用超极化气体（如3He和129He）的MRI已被广泛应用。 然而，它们具有与成本，实现的复杂性， 现有设备的兼容性，以及气体的一些不可忽略的生物效应。该项目将 提供一种基于雾化超极化水蒸气（AHWV）的替代方法， 生物相容性，便携式，与现有的成像硬件兼容，并将允许探测肺容量， 不同的长度尺度。该方法基于水的Overhauser动态核极化（ODNP）， 随后使超极化的水雾化，使得其可以被成像。对于这个探索性的项目，我们 将开发一个开源的，低场（0.2T）ODNP系统，以高密度水在液相中，将 通过气溶胶化反应器快速蒸发。将研究水蒸气形式的弛豫特性 在不同的磁场强度、温度和雾化方法下， 蒸汽极化的条件，输送到测量体积和灵敏度的优化。的 方法将在3T动物扫描仪上的小鼠动物模型上进行。总的来说，我们将建立一个有效的 方法hyperplastion和雾化水，并将开发必要的工具，以获得 超极化的空气中的水在空的空间图像。这项研究有望为这一新的 便携、经济、灵活的气道成像模式。

Project Summary Detecting and characterizing lung disorders and their impacts on the airways by imaging is extremely challenging due to the low tissue density. Few options exist to characterize the changes in the microscopic properties of air access and tissue changes in diseases such as asthma, pneumonia, bronchitis, Covid-19, and chronic obstructive pulmonary disease. MRI with hyperpolarized gasses, such as 3He and 129Xe have been used to fill this gap, which however have their own limitations related to cost, complexity of implementation, compatibility of existing equipment, and some non-negligible biological effects of the gasses. This project will deliver an alternative approach, based on aerosolized hyperpolarized water vapor (AHWV), which will be fully biocompatible, portable, compatible with existing imaging hardware, and will allow probing lung volume at different length scales. The approach is based on Overhauser Dynamic Nuclear Polarization (ODNP) of water, followed by aerosolization of hyperpolarized water such that it can be imaged. For this exploratory program, we will develop an open-source, low field (0.2T) ODNP system to hyperpolarize water in the liquid phase that will be rapidly vaporized by an aerosolization reactor. Relaxation properties of water in vapor form will be studied at different magnetic field strengths, temperatures and aerosolization approaches to determine the optimal conditions for vapor polarization, delivery into the measurement volume and optimization of sensitivity. The method will be on a mouse animal model on a 3T animal scanner. Overall, we will establish an effective method to hyperpolarize and aerosolize water and will develop the necessary tools required to acquire hyperpolarized water-in-air images in void-spaces. The study is expected to lay the foundation for this new portable, cost-effective, and flexible imaging modality for the airways.