NMR PROTON CHEMICAL SHIFT IMAGING

第一个核磁共振图像产生于1973年； 在接下来的几年里，仪器设备取得了重大进展 和技巧。与成像技术的发展同步进行核磁共振 光谱技术已经随着频率的增加而被应用到 研究生物系统。这笔赠款的目标是进一步发展和 评估获取质子光谱(化学位移)的技术 核磁共振图像中的信息。具体地说，努力将集中在两个方面 主要目标。第一，测量信号强度和 质子谱的两个主要贡献者的弛豫时间， 脂肪和水，将使用三种化学位移成像进行测试 技巧。幻影数据将被用来验证理论预测 S/N和技术偏向。伴有和不伴有脂肪肝的大鼠模型 伴随的肝炎将被用于验证这些观察结果 并比较常规核磁共振技术对核磁共振的敏感性。 利用多组分弛豫时间的三种化学位移成像方法 测量。然后研究将扩展到对人类的调查 肝脏病理学。为了便于将信息快速传输到 临床环境，人类骨髓的研究将在#年进行 与动物肝脏研究平行。这些将首先集中在模式上 骨髓发育正常。人骨髓的初步研究 然后进行白血病，测试多种成分的能力 测量以确定正常和异常的骨髓元素。 这项研究的第二个具体目的是利用质子化学位移 全脑和局灶性低氧时脑乳酸的成像技术 侮辱。乳酸测定的灵敏度、精密度和准确度 将在模体中确定，水和水的评估技术 抑制血脂。将在大鼠身上进行非成像实验，以 在体内评估系统线性，组织乳酸弛豫时间 在一定的浓度范围内被测定。全球的猫脑模型 暂时稳定的低氧将与大脑乳酸水平一起成像 生化测定与乳酸盐图像信号强度比较。这 该模型可推广应用于局灶性脑缺血损伤的研究。试点研究 还将进行乳酸在人体内积累的研究，调查 中风和中枢神经系统肿瘤患者。

The first nuclear magnetic resonance (NMR) images were produced in 1973; in the ensuing years significant advances have been made in instrumentation and technique. Concurrent with developments in imaging technology NMR spectroscopic techniques have been applied with increasing frequency to study biological systems. The goal of this grant is to further develop and evaluate techniques which acquire proton spectroscopic (chemical shift) information within an NMR image. Specifically, efforts will focus on two primary aims. First, the ability to measure signal intensity and relaxation times of the two primary contributors to the proton spectra, lipid and water, will be tested using three chemical shift imaging techniques. Phantom data will be used to verify theoretical predictions of S/N and technique bias. Rat models of hepatic steatosis with and without the concomitant hepatitis will be used to validate these observations in vivo, and to compare the sensitivity of conventional NMR techniques to the three chemical shift imaging methods using multicomponent relaxation time measurements. Studies will then be extended to the investigation of human liver pathology. In order to facilitate rapid transfer of information to the clinical environment, studies of human bone marrow will be made in parallel with animal liver studies. These will first focus on patterns of normal bone marrow development. A pilot study of bone marrow in human leukemias will then be carried out, testing the ability of multicomponent measurements to characterize normal and abnormal marrow elements. The second specific aim of this study is to use proton chemical shift imaging techniques to map cerebral lactate during global and focal hypoxic insult. The sensitivity, precision and accuracy of lactate measurements will be determined in phantoms, evaluating techniques of both water and lipid suppression. Non-imaging experiments in rats will be carried out to evaluate system linearity in vivo, and tissue lactate relaxation times will be determined over a range of concentrations. A cat brain model of global hypoxia, temporally stabalized, will be imaged, with brain lactate levels determined biochemically compared to lactate image signal intensity. This model wil be extended in studies of focal ischemic insult. Pilot studies of lactate accumulation in humans will also be carried out, investigating stroke and CNS tumor patients.