Department of Biomedical Engineering and Environmental Sciences, College of Nuclear Science, National Tsing Hua University, Hsinchu, Taiwan.
NMR Biomed. 2013 Jun;26(6):692-8. doi: 10.1002/nbm.2914. Epub 2013 Jan 28.
Deuterium oxide (D2 O), which is commercially available and nonradioactive, was proposed as a perfusion tracer before the clinical usage of conventional gadolinium-based MRI contrast agents. However, the sensitivity of direct deuterium detection is the major challenge for its application. In this study, we propose a contrast-enhanced strategy to indirectly trace administered D2 O by monitoring the signal attenuation of (1) H MRI. Experiments on D2 O concentration phantoms and in vivo rat brains were conducted to prove the concept of the proposed contrast mechanism. An average maximum signal drop ratio of 5.25 ± 0.91% was detected on (1) H MR images of rat brains with 2 mL of D2 O administered per 100 g of body weight. As a diffusible tracer for perfusion, D2 O infusion is a practicable method for the assessment of tissue perfusion and has the potential to provide different information from gadolinium-based contrast agents, which have limited permeability for blood vessels. Furthermore, the observed negative relaxivities of D2 O reveal the (1) H-D exchange effect. Therefore, applications of perfusion MRI with D2 O as a contrast agent are worthy of further investigation.
重水（D2O），商业上可获得且无放射性，在常规基于钆的 MRI 造影剂的临床应用之前，被提议作为灌注示踪剂。然而，直接检测氘的灵敏度是其应用的主要挑战。在这项研究中，我们提出了一种对比增强策略，通过监测（1）H MRI 的信号衰减来间接追踪给予的 D2O。我们在 D2O 浓度体模和体内大鼠脑中进行了实验，以证明所提出的对比机制的概念。在给予每 100 克体重 2 毫升 D2O 的大鼠脑的（1）H MR 图像上，检测到平均最大信号下降比为 5.25±0.91%。作为灌注的可扩散示踪剂，D2O 输注是评估组织灌注的一种可行方法，并且有可能提供与血管通透性有限的基于钆的造影剂不同的信息。此外，观察到的 D2O 的负弛豫率揭示了（1）H-D 交换效应。因此，使用 D2O 作为对比剂的灌注 MRI 的应用值得进一步研究。
