PHYSIOLOGICAL MR STUDIES USING HYPERPOLARIZED 129XE

使用超极化 129XE 进行生理 MR 研究

• 批准号: 2227939
• 负责人: CHARLES S. SPRINGER
• 金额: $ 28.85万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2227939
• 关键词: analytical method; brain neoplasms; clinical biomedical equipment; diagnosis quality /standard; laboratory mouse; laboratory rat; magnetic resonance imaging; noninvasive diagnosis; nuclear magnetic resonance spectroscopy; phantom model; physiology; technology /technique; technology /technique development; xenon

The noble gas xenon is a safe and effective general anesthetic. Rapidly absorbed via the lung into the blood-stream, it concentrates in lipid- rich tissue with a time-dependence related to blood flow. A major isotope, Xe, has a spin 1/2 nucleus with a chemical shift remarkably sensitive to van de Waals environment (range, 300 ppm). Its T and T values are quite sensitive to O2 concentration and other factors. The crucial point is that, prior to administration, Xe can readily be hyperpolarized, 105-106 fold by spin exchange with optically pumped rubidium: its NMR signal strength (and thus time and space resolution) at 20 mM, would be comparable to that of tissue water proton at 80-100 M: This unique property of Xe, as well as its distinctly different behavior compared to H2O in(a) cell and tissue compartmentalization, (b) and subcellular exchange kinetics, will provide a new adequate quantities of hyperpolarized Ce (Xet). Procedures for imaging, Combined Spectroscopy and Imaging (CIS), and image-guided analysis of local T and T probability distributions (Relaxography), well-established in our laboratory for H and Na, will be applied to the new modality. Parameters for determining and optimizing time and space resolution will be obtained using pattern-drilled Teflon phantoms for Xegas. Parameters for CSI will be obtained using a water-octanol-gas phantom. Overall behavior in the mouse will assayed in several large voxels-the lung gas space, the whole brain, and a large muscle. The dynamics of Xe exchange, compartmentalization and relaxation at the cellular and subcellular level will be determined from the behavior of the chemical shift, line shape, T and T2 in nonimaging studies of model systems of hierachiacal complexity, for a range of O2 concentrations. The dynamics of transport, distribution, and lifetime of Xe in the mouse and rat in vivo will be investigated in other major organs, and peripheral tissues. The pharmacokinetics behavior of an anesthetic is important in its own right. Finally, three well-known mouse and rat paradigms will be studied (a) effects of hypoxia, hyperopia and hypercapnia (excess CO2) on blood flow and Xe in brain and elsewhere; (b) effects of stimulating individual mystical vibrissae (facial whiskers) on Xe in the 'barrel field' area of the somatosensory region of the mouse brain; (c) effect on Xe images (correlated with H imaging and CONTIN analysis of T) of development of tumors following injection of 2X10 KHT sarcoma cells into the mouse gastrocnemius, and similar studies with a metastasizing adenocarcinoma and a brain glioma.

惰性气体氙是一种安全有效的全身麻醉剂。 迅速 通过肺部吸收进入血液，它集中在脂质中 丰富的组织与血流具有时间依赖性。 一个专业 同位素 Xe 具有自旋 1/2 原子核，具有显着的化学位移 对范德瓦尔斯环境敏感（范围，300 ppm）。 它的T和T 值对 O2 浓度和其他因素非常敏感。 这 关键的一点是，在给药之前，Xe 可以很容易地被 超极化，通过光泵浦自旋交换实现 105-106 倍 铷：其 NMR 信号强度（以及时间和空间分辨率） 20 mM 时，与组织水质子 80-100 相当 M：Xe的这种独特性质，以及它明显不同的特性 与 H2O 相比，(a) 细胞和组织区室化的行为，(b) 和亚细胞交换动力学，将提供新的足够的量 超极化 Ce (Xet)。 组合成像程序 光谱学和成像 (CIS) 以及局部 T 和图像引导分析 T 概率分布（松弛图），在我们的 H 和 Na 实验室将应用于新模式。 参数 用于确定和优化时间和空间分辨率将获得 使用 Xegas 的图案钻孔 Teflon 模型。 CSI 的参数将 可以使用水-辛醇-气体模型获得。 总体行为在 小鼠将在几个大体素中进行分析——肺气体空间、整个 大脑和大块肌肉。 Xe交换的动态， 细胞和亚细胞水平的区室化和松弛 将由化学位移、线形状的行为确定， 分层模型系统非影像研究中的 T 和 T2 复杂性，适用于一系列 O2 浓度。 运输动态， Xe 在小鼠和大鼠体内的分布和寿命将 对其他主要器官和外周组织进行了研究。 这 麻醉剂的药代动力学行为本身就很重要。 最后，将研究三种著名的小鼠和大鼠范例（a） 缺氧、远视和高碳酸血症（过量二氧化碳）对血流的影响 Xe 在大脑和其他地方； (b) 刺激个人的效果 Xe 上“桶状场”区域神秘的触须（面部胡须） 小鼠大脑的体感区域； (c) 对 Xe 图像的影响 （与 H 成像和 T 的 CONTIN 分析相关） 将 2X10 KHT 肉瘤细胞注射到小鼠体内后的肿瘤 腓肠肌以及转移性腺癌的类似研究 和脑胶质瘤。