PHYSIOLOGICAL MR STUDIES USING HYPERPOLARIZED 129XE

使用超极化 129XE 进行生理 MR 研究

• 批准号: 2227941
• 负责人: CHARLES S. SPRINGER
• 金额: $ 17.13万
• 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 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2227941
• 关键词: analytical method; bioimaging /biomedical imaging; 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; vibrissae; 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.

稀有气体氙气是一种安全有效的全身麻醉剂。迅速地 它通过肺吸收进入血液，浓缩在脂质中- 丰富的组织具有与血流有关的时间依赖性。一位少校 同位素Xe有一个自旋1/2的原子核，具有显著的化学位移 对范德华环境敏感(范围，300ppm)。它的T和T 数值对氧气浓度和其他因素相当敏感。这个 关键是，在管理之前，Xe可以很容易地 超极化，通过光泵浦的自旋交换获得105-106倍 Rb：其核磁共振信号强度(因此具有时间和空间分辨率) 在20毫米，将相当于组织水质子在80-100 M：Xe的这一独特性质，以及它的独特之处 (A)细胞和组织区隔中的行为与H2O的比较，(B) 和亚细胞交换动力学，将提供新的适量 超极化Ce(Xet)。成像程序，组合 光谱学和成像(CIS)，以及图像引导的局部T和 T概率分布(重定位)，在我们的 H和Na的实验室，将应用于新的模式。参数 为了确定和优化时间和空间分辨率，将获得 为Xegas使用图案钻过的特氟龙幻影。CSI的参数将 使用水-辛醇-气体模体获得。中的整体行为 小鼠将在几个大的体素中进行分析-肺气体空间，整个 大脑，还有一大块肌肉。Xe交换的动力学， 细胞和亚细胞水平的区隔和松弛 将由化学位移的行为，线条形状， 分层模型系统非成像研究中的T和T_2 复杂性，对于一定范围内的氧气浓度。运输的动态， Xe在小鼠和大鼠体内的分布和寿命将是 在其他主要器官和外周组织中进行了研究。这个 麻醉剂的药代动力学行为本身就很重要。 最后，我们将研究三个著名的小鼠和大鼠范例(A) 低氧、远视和高碳酸血症(过量二氧化碳)对血流的影响 和Xe在大脑和其他地方；(B)刺激个体的效果 神秘的触须(面部胡须)在Xe上的‘桶田’地区 小鼠脑的体感区域；(C)对Xe图像的影响 (与T的H成像和CONTIN分析相关) 小鼠体内注射2X10 KHT肉瘤细胞后的肿瘤 腓肠肌和转移性腺癌的类似研究 还有一个脑胶质瘤。