NMR PROTON CHEMICAL SHIFT IMAGING

第一个核磁共振（NMR）图像于1973年产生; 在随后的几年里，在仪器仪表方面取得了重大进展 和技巧。 随着核磁共振成像技术的发展， 光谱技术已经越来越频繁地应用于 研究生物系统。 这项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 NMR图像中的信息。 具体而言，工作将集中在两个方面 主要目标。 首先，测量信号强度的能力， 质子谱的两个主要贡献者的弛豫时间， 脂质和水，将使用三种化学位移成像进行测试 技术. 体模数据将用于验证以下理论预测： S/N和技术偏差。 肝脂肪变性大鼠模型， 合并肝炎将用于验证这些观察结果， 体内，并比较常规NMR技术的灵敏度， 三种利用多组分弛豫时间的化学位移成像方法 测量. 研究将扩展到人类的研究。 肝脏病理学 为了便于迅速将信息传递给 在临床环境下，人类骨髓的研究将在 与动物肝脏研究平行。 这些将首先集中在模式， 正常的骨髓发育 人骨髓的初步研究 然后将进行白血病，测试多组分的能力， 测量以表征正常和异常骨髓元素。 本研究的第二个具体目的是利用质子化学位移 成像技术用于绘制全局和局灶性缺氧期间的脑乳酸 侮辱。 乳酸测定的灵敏度、精密度和准确度 将在幻影中确定，评估水和 脂质抑制。 将在大鼠中进行非成像实验， 评价系统在体内的线性，组织乳酸盐弛豫时间将 在一定浓度范围内测定。 一个猫脑的全局模型 缺氧，暂时稳定，将成像，脑乳酸水平 与乳酸盐图像信号强度相比，生物化学测定。 这 模型可推广应用于局灶性脑缺血损伤的研究。 试点研究 也将进行人体乳酸积累的研究， 中风和CNS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.