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

项目摘要 通过成像来检测和表征肺部疾病及其对呼吸道的影响是非常重要的 由于组织密度低，具有挑战性。几乎没有选择来描述微观上的变化 哮喘、肺炎、支气管炎、新冠肺炎和其他疾病的呼吸道特性和组织变化 慢性阻塞性肺病。具有超极化气体的磁共振成像，如3He和129Xe，已经被 用于填补这一空白，但有其自身的限制与成本、实施的复杂性， 现有设备的兼容性，以及气体的一些不可忽视的生物影响。这个项目将 提供另一种方法，基于气雾化超极化水蒸气(AHWV)，它将完全 生物兼容、便携、与现有成像硬件兼容，并将允许在 不同的长度刻度。该方法基于水的Overhauser动态核极化(ODNP)， 然后是超极化水的气雾化，这样它就可以被成像。对于这个探索性项目，我们 将开发一种开源的低场(0.2吨)ODNP系统，使液体中的水超极化，这将 被气雾化反应器迅速汽化。我们将研究水蒸气形式的水的松弛特性。 在不同磁场强度、温度和气雾化方式下确定最佳 蒸气极化条件、进入测量体积的条件和灵敏度的优化。这个 该方法将在3T动物扫描仪上对小鼠动物模型进行实验。总体而言，我们将建立有效的 超极化和气雾化水的方法，并将开发必要的工具，以获得 真空空间中的超极化空气中的水图像。这项研究有望为这一新的 便携、经济实惠、灵活的呼吸道成像设备。

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.