GAS INJECTION USING A SPECIAL CATHETER FOR LUNG PERFUSION IMAGING IN THE RAT

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 最近，一种新的成像方法被开发出来，用于肺血流和肺气体交换的成像。它是基于静脉注射(尾静脉或颈静脉)溶解于生理盐水的超极化(HP)129Xe。129Xe通过肺部被清除，在那里它可以以相对较高的分辨率成像。除了绘制血流灌注图外，还可以从重复成像或光谱分析中获得定量信息，并对Kty-Schmidt理论进行修正。 新项目旨在通过直接注入气体取代溶解在盐水中的HP 129Xe来避免注入更大量的液体。为了避免在注射过程中产生气泡而造成肺栓塞，将使用一种新型的导管。导管含有微孔中空纤维膜(一种薄壁、不透明的聚合物膜，用于各种医疗、控制释放或生物技术应用)。它具有亚微米孔隙率、相对较高的耐爆强度和优异的耐化学性。由于其疏水性和小孔尺寸，该膜除了在高压下外，还能抵抗水的渗透。该项目将分为三个阶段：(1)在体模实验中验证无气泡的129Xe注射到房水中；(2)复制先前通过膜促进直接气体注射在10只大鼠身上获得的生理盐水注射结果；(3)在10只大鼠身上进行高分辨率灌注成像(平面内亚毫米体素尺寸，切片厚度5 mm或更小)。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Recently, a novel imaging method for imaging lung perfusion and pulmonary gas exchange has been developed at CIVM. It is based on venous injection (tail vein or jugular vein) of hyperpolarized (HP) 129Xe dissolved in saline. 129Xe is cleared through the lungs where it can be imaged with relatively high resolution. In addition to mapping perfusion, quantitative information may be obtained from repetitive imaging or spectroscopy and adaptation of the Kety-Schmidt theory. The new project aims at avoiding injection of larger quantities of fluid by replacing injections of HP 129Xe dissolved in saline with direct gas injections. To avoid creation of pulmonary embolism due to production of gas bubbles during the injections, a novel type of catheter will be used. The catheter contains a microporous hollow-fiber membrane (a thin-walled, opaque, polymer membrane that is used in a variety of medical, controlled-release, or biotechnological applications). It features submicron porosity, relatively high burst strengths, and excellent chemical resistance. Due to their hydrophobic properties and small pore size, the membrane resists water permeation, except at high pressures. The project will be divided into three phases: (1) verification of the bubble-free 129Xe injection into aqueous fluids in a phantom experiment; (2) replication of previous results obtained with saline injections by using membrane-facilitated direct gas injections in 10 rats; (3) high-resolution perfusion imaging (in-plane submillimeter voxel dimensions, slice thickness 5mm or less) in 10 rats.