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

本项目的目的是：1)了解生物系统中水的核磁共振弛豫的控制因素；2)开发基于双量子滤波核磁共振和化学位移成像的新型功能磁共振成像，以遵循水的“有序”结构，并用它来了解健康和病理组织的生理过程。1)双量子滤波核磁共振成像的发展：我们推出了H-1层选择性双量子滤波核磁共振成像（H-1 DQF MRI），选择性地描绘生物组织中有序水（结合水），并开发了H-1和H-2化学位移双量子滤波核磁共振成像（H-1和H-2 DQF CSI），通过选择性窗口描绘一定分子环境中的水。2)用H-1 DQF MRI评估跟腱断裂愈合过程：组织的DQF信号依赖于DQ产生时间τ。在21周的愈合过程中，H-1 DQF图像发生了显著变化。这些变化与愈合过程的阶段相匹配。通过使用τ加权对比，DQF图像显示肌腱未完全愈合的部分，即使在常规MRI显示正常后。3) H-1 DQF MRI在体内系统上的应用：采用a4.7T动物MR扫描仪对麻醉家兔后肢进行H-1 DQF MRI扫描。跟腱和其他肌腱被很好地描绘为突出显示。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.