MULTINUCLEAR IN VIVO MRI/MRS--DEVELOPMENT & APPLICATION

多核体内 MRI/MRS——开发

基本信息

批准号：
3187231
负责人：
JOEL F MARTIN
金额：
$ 13.88万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-02-01 至 1991-01-31
项目状态：
已结题

项目摘要

The proposed research is a multifaceted approach to the development of practical methods of multinuclear magnetic resonance imaging and spectroscopy. The research will be directed principally toward imaging of the 19F nucleus, though the techniques and hardware described are directly applicable to other nuclei. The imaging/spectroscopy experiments will be carried out using a combination of new pulse sequences, new hardware and new signal processing techniques. Developments in each of these areas are necessary to overcome the onerous difficulties inherent in multinuclear in vivo MR. Two new chemical shift imaging sequences are presented which complement ordinary spin warp and gradient echo imaging. These novel sequences eliminate the artifacts associated with large chemical shifts. Gradient pulses for flow compensation are discussed. Designs for switchable coils which can be used for 19F and 1H imaging and localized spectroscopy are also presented. Signal processing techniques are described which can limit the acquisition times and interferogram size of chemical shift experiments. These signal processing techniques may be applied directly to normal 1H imaging and two-dimensional NMR. The 19F imaging experiments will be conducted using perfluoroctylbromide. This compound is an excellent solvent for 02 and CO2 and is reasonably inert, because of these properties it can be used as a "blood substitute". 19F imaging of perfluorocarbon blood substitutes is important, since 19F relaxation rates are strongly influenced by 02 tension. The indirect measurement of pO2 in tissues via 19F MRI would prove extremely important in visualizing lung diseases, ischemic or necrotic tissues, or neoplasms. Perfluoroctylbromide has already been demonstrated as an effective radiographic and ultrasound contrast agent for tumor delineation.

拟议的研究是一种多方面的方法开发多核磁性的实用方法共振成像和光谱法。研究将是主要针对19F核的成像所描述的技术和硬件直接适用于其他核。成像/光谱实验将是使用新的脉冲序列的组合，新的硬件和新信号处理技术。发展这些领域中的每一个都必须克服繁重的多核体内MR固有的困难。提出了两个新的化学移位成像序列补充普通的旋转和梯度回声成像。这些新序列消除了与大型相关的伪影化学移位。用于流动补偿的梯度脉冲是讨论。可切换线圈的设计，可用于19F 还提出了1H成像和局部光谱。描述了信号处理技术，可以限制化学移位的采集时间和干涉图实验。这些信号处理技术可以应用直接达到正常的1H成像和二维NMR。 19F成像实验将使用全氟辛基溴。该化合物是一个极好的溶剂 02和CO2，并且由于这些属性是合理的惰性可以用作“血液替代品”。 19f成像全氟化合物血液替代物很重要，因为19f 放松率受02张力的强烈影响。这通过19F MRI在组织中PO2的间接测量将证明在可视化肺部疾病，缺血性或坏死组织或肿瘤。全氟辛基溴已经存在被证明是有效的射线照相和超声肿瘤描述的对比剂。