Proposal of New Functional NMR Imaging : Development of Double-Quantum-Filtered MRI

本项目的目标是：1)了解影响生物体系中水的核磁共振弛豫的因素；2)发展基于双量子滤光片核磁共振和化学位移成像的新型功能性磁共振成像，跟踪水的“有序”结构，并利用它来了解健康和病理组织中的生理过程。1)双量子滤光片核磁共振成像的发展：我们引入了H-1层选择性双量子滤光片核磁共振成像(H-1 DQF MRI)，它选择性地描绘生物组织中有序的水(结合水)。并发展了H-1和H-2化学位移双量子滤光片核磁共振成像(H-1和H-2 DQF-CSI)，通过选择窗口来描述特定分子环境中的水。2)H-1DQF磁共振对跟腱断裂愈合过程的评估：组织的DQF信号依赖于DQ产生时间τ。在21周的跟腱损伤愈合过程中，H-1DQF图像发生了显著变化。这些变化与愈合过程的各个阶段相匹配。使用τ加权对比图显示肌腱未完全愈合的部分，即使常规MRI显示正常。3)H-1DQF MRI在活体系统上的应用：使用4.7T动物磁共振扫描仪，对麻醉兔的后肢进行H-1DQF MRI检查。跟腱和其他肌腱如突出显示的那样被清楚地描绘出来。我们仍在继续优化测量参数，但我们已经为下一步：人类应用收集了足够的基本数据。

The Aims of this project is 1) to reach an understanding of factors governing the NMR relaxation of water in biological systems and 2) to develop new functional MR imaging based on the double-quantum-filter NMR and the chemical shift imaging to follow "order" structure of water and to use it to understand physiological processes in healthy and pathological tissues.1) Development of double-quantum-filter NMR imaging : We have introduced H-1 slice selective double-quantum-filter NMR imaging (H-1 DQF MRI) which depicted ordered water (bound water) in biological tissues selectively, and also developed H-1 and H-2 chemical shift double-quantum-filter NMR imaging (H-1 and H-2 DQF CSI) which depict water in a certain molecular environment through selective window.2) Assessment of healing process of ruptured Achilles tendon by H-1 DQF MRI : Tissues are characterized by the dependence of their DQF signal on the DQ creation time, τ. The H-1 DQF image changed dramatically during the healing process on the injured Achilles tendon for 21 weeks. These changes matched the phases of the healing process. By using a τ-weighted contrast, the DQF images indicate the part of tendon which has not completely healed, even after the conventional MRI appeared normal.3) Application of H-1 DQF MRI on in vivo system : Using a4.7T animal MR scanner, H-1 DQF MRI was applied hind limbs of anesthetized rabbits. The Achilles tendon and other tendons were well depicted as highlighted. We still continue to optimize parameters for measurement, but we have already collect enough basic data for the next step : human application.