氧化氘（D2O）因其為純水之無放射性同位素且幾乎不具生物毒性，被廣泛應用於核磁共振與磁振造影研究中。然而，作為早期微灌流磁振造影的對比劑之一，重水影像卻受限於磁振造影偵測靈敏度的限制。因此，我們改以一般收取氫原子訊號的方式來間接檢測非共振頻率重水的微灌流影像。本實驗中，含有血清蛋白的假體實驗與活體鼠腦動態影像分別用以檢測新式的重水對比機制。在生理訊號方面，我們於三種不同的動物實驗中欲建立清楚的影像對比參數，並透過血液微灌流參數分析來評估不同生理情況對血流速的影響。實驗結果顯示高解析度的質子加權影像較不受磁化率的影響且清楚對比出重水微灌流於灰質與白質之間的差異；假體實驗亦指出重水於高濃度血清蛋白中有顯著的對比差異。基於自由通透血腦障蔽之特性，高解析度重水微灌流影像可於未來研究中對比腦神經病變的可能組織並以血流速分析提供臨床術前術後之病人康復評估。

Deuterium oxide (D2O), which is a nonradioactive and relatively nontoxicity isotope of pure water, was applied as a contrast agent in early NMR and MRI studies. The researches have proved D2O can be utilized as an effective perfusion tracer. However, the detection of deuteron signal was limited to its theoretical sensitivity. Herein we apply an indirect detection strategy to trace administered D2O by monitoring 1H signal attenuation. In this study, phantom experiments were conducted to investigate this novel contrast mechanism. Furthermore, in vivo rat brain imaging was performed on three cases with respective contrast parameters: (1) carotid artery injection, (2) normocapia and hypercapnia models, and (3) infusion administration. Quantitative analysis provides alternative perfusion information against gadolinium-based imaging approaches. Contrast between gray matter and white matter can also be observed in high-resolution imaging. The results suggest proton density-weighted imaging is potential to exhibit better SNR with less susceptibility artifacts. As a freely diffusible tracer, applications of D2O perfusion MRI are especially valuable for its fast exchange with water proton in future research.

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