MRI OF HYPERPOLARIZED NOBLE GASES

超极化惰性气体（3 He， 129年）开辟了高分辨率成像的可能性， 生理上重要的空气空间，如肺和鼻窦， 在常规质子核磁共振成像中几乎不可见。 一 超极化气体的基本性质，使它们 非常有希望的高分辨率MRI，是他们的异常 大的非平衡核极化 这表明， 超极化气体可用于生成 肺部以及评估鼻窦通气。 总目标 该项目的目的是推进新的MRI技术， 超极化惰性气体成像到临床应用阶段，以及 以确定将其用作诊断工具的可行性 术前和术后评估的患者接受了 肺减容手术或功能性鼻窦手术。 在过去的12个月里，我们建造并组装了 超极化所需的设置组件，包括 高真空气体处理系统和基于二极管的光学单元 阵列激光器 我们已经能够产生适度的 3 He极化（高达6.5%）。 我们得到了一系列的图像 一个正常志愿者和一个慢性阻塞性肺病患者的肺。 的 图像清楚地显示了不同肺叶的边界， 气管、主支气管和一些较小的气道。 的图像 从健康受试者中获得的结果显示均匀分布 吸入的气体，从而表明正常通风的 薄壁组织 相比之下，患者的肺部表现出高度的 不均匀的分布模式，后来与 使用动脉自旋标记和放射成像获得的图像 成像方法。 我们还首次证明， 超极化~ 3 He在人副鼻窦内显像可行性 ses。 所有四种类型的鼻窦都清楚地描绘在 3 He图像。

Recent advances in the imaging of hyperpolarized noble gases (3He, 129Xe) has opened up the possibilities for high resolution imaging of physiologically important airspaces, such as lungs and sinuses, which are otherwise virtually invisible to conventional proton MRI. A fundamental property of the hyperpolarized gases, one which makes them extremely promising for high resolution MRI, is their exceptionally large non-equilibrium nuclear polarization. This suggests that MRI of hyperpolarized gases can be useful in generating ventilation maps of the lungs, as well as assessing sinus ventilation. The overall goal of this project is to advance the novel MRI technique of hyperpolarized noble gas imaging to a clinically applicable stage, and to establish the feasibility of using it as a diagnostic tool in the pre- and post-operative evaluation of patients who undergo either a lung volume reduction surgery or a functional sinus surgery. Over the past 12 months we have built and assembled the components of the setup required for hyperpolarization, including a high-vacuum gas handling system and an optical unit based on a diode array laser. We have been able to produce a moderate degree of polarization in 3He (up to 6.5%). We have obtained a series of images of the lungs of both a normal volunteer and a patient with COPD. The images clearly showed the boundaries of different lung lobes, the trachea, the major bronchi, and some smaller airways. The images obtained from the healthy subject displayed homogeneous distribution of the inhaled gas, thus suggesting normal ventilation of the parenchyma. In contrast, the patient's lungs exhibited highly inhomogeneous pattern of distribution which was later correlated with images obtained using both arterial spin labeling and radionuclear methods of imaging. We have also demonstrated, for the first time, the feasibility of imaging hyperpolarized 3He in human paranasal sinu ses. All four types of paranasal sinuses were clearly depicted in the 3He images.