RECYCLE OF 3HE FOR HIGH-RESOLUTION LUNG IMAGING

稀有气体同位素可以被核自旋极化，是非常有吸引力的成像剂，因为它们对核磁共振具有很高的检测灵敏度。特别是，自旋极化3He使肺和气道的快速、气体空间成像用于临床诊断和生理研究。不幸的是，3He的有限可用性严重限制了可进行的高分辨率肺部成像研究的数量。我们建议开发一个系统来回收和循环利用稀有的氦同位素，使高分辨率的肺部成像变得普遍和廉价。这项创新是一种低温气体分离系统，可以从患者呼出的气体中提取和净化3He，并将其保存下来，以便重新极化，并在其他患者中重复使用。在第一阶段，我们将通过(1)进行概念验证测试来证明He回收系统的可行性，该测试证明了从呼出气体中有效分离、净化和灭菌3He的可行性，以及(2)产生一个完整系统的概念设计来回收和循环利用3He。在第二期，我们将建立和示范一个完整的回收和循环再造系统。建议的商业应用：稀有稀有气体同位素如果能够经济地使用，将是医学成像的一个潜在突破。这些同位素的用途包括高分辨率，肺和气道的气体空间成像，实用的低场MRI，使用可溶性同位素研究血液灌注和脑生理学，以及基于气态同位素扩散的多孔介质研究。该计划开发的技术将使这些稀有同位素能够多次重复使用，从而使这些进步变得实用和经济。

Noble gas isotopes that can be nuclear spin-polarized are very attractive imaging agents ,because of their high detection sensitivity for nuclear magnetic resonance. In particular, spin-polarized 3He enables fast, gas- space imaging of the lungs and airways for clinical diagnosis and physiological studies. Unfortunately, the limited availability of 3He severely limits the number of high-resolution lung imaging studies that can be performed. We propose to develop a system to recover and recycle the rare helium isotope so that high-resolution lung imaging can become common and inexpensive. The innovation is a cryogenic gas separation system that extracts and purifies the 3He from a patient's exhalation stream and saves it for re-polarization3 and reuse in other patients. In Phase I we will prove the feasibility of the He recovery system by (l) performing a proof-of-concept test that demonstrates the feasibility of efficiently separating, purifying, and sterilizing the 3He from exhalation gases, and (2) producing a conceptual design of a complete system to recover and recycle 3He. In Phase II we will build and demonstrate a complete recovery and recycling system. PROPOSED COMMERCIAL APPLICATIONS: Rare, noble gas isotopes are a potential breakthrough for medical imaging if they could be used economically. Uses for these isotopes include high- resolution, gas-space imaging of the lungs and airways, practical low-field MRI, studies of blood perfusion and brain physiology using soluble isotopes, and porous media studies based on diffusion of gaseous isotopes. Technology developed in this program will make these advances practical and economical by enabling these rare isotopes to be reused many times.