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

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 最近，CIVM开发了一种用于成像肺灌注和肺气体交换的新型成像方法。它是基于静脉注射（尾静脉或颈静脉）溶解在盐水中的超极化（HP）129？。129微克通过肺部被清除，在那里它可以以相对高的分辨率成像。除了映射灌注之外，定量信息可以从重复成像或光谱学和Kety-Schmidt理论的适应中获得。 新项目旨在通过直接注入气体来取代溶解在盐水中的HP 129 NH 4的注入，从而避免注入大量液体。为了避免由于注射过程中产生气泡而导致肺栓塞，将使用一种新型导管。该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、控释或生物技术应用）。它具有亚微米孔隙率、相对较高的破裂强度和优异的耐化学性。由于它们的疏水性和小孔径，膜抵抗水渗透，除了在高压下。该项目将分为三个阶段：（1）在体模实验中验证无气泡129氚注射到水性液体中;（2）通过使用膜促进的直接气体注射在10只大鼠中复制先前使用盐水注射获得的结果;（3）在10只大鼠中进行高分辨率灌注成像（面内亚毫米体素尺寸，切片厚度为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. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 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 devided 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.