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

该项目的目的是1）了解生物系统中水的NMR弛豫的控制因素; 2）开发基于双量子滤波器NMR和化学位移成像的新功能MR成像，以跟踪水的“有序”结构，并使用它来了解健康和病理组织中的生理过程。介绍了H-1切片选择性双量子滤波核磁共振成像（H-1 DQF MRI），描绘了有序水（结合水）在生物组织中选择性地，并开发了H-1和H-2化学位移双量子滤波NMR成像（H-1和H-2 DQF CSI），通过选择性窗口描述了特定分子环境中的水。2）H-1 DQF MRI对跟腱断裂愈合过程的评估：组织的特征在于其DQF信号对DQ创建时间τ的依赖性。H-1 DQF图像在21周的跟腱损伤愈合过程中发生了显著变化。这些变化与愈合过程的阶段相匹配。利用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显示正常的情况下。3）H-1 DQF MRI在活体系统中的应用：使用4.7T动物MR扫描仪，对麻醉家兔后肢进行H-1 DQF MRI。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收集了足够的基础数据：人类应用。

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.