| Summary: | 碩士 === 國立清華大學 === 生醫工程與環境科學系 === 103 === In early perfusion MRI studies, D2O had been used as a high diffusible tracer. It was verified that D2O can be applied as an effective contrast agent. Due to the limitation of theoretical sensitivity on deuterium images, the signal to noise ratio (SNR) is too low to acquire distinctly anatomical details. In recent study, a new strategy for detecting D2O by monitoring the attenuation of 1H signal has been suggested. By using this new strategy, we further research the microcirculation of D2O and establish a kinetic model. In this study, one and two compartments models were proposed to depict the dynamics of D2O in rat brain. The kinetic parameters were derived from compartmental models by de-convolution. It is showed that the two compartments model could give a more accurate but less precise in the estimation of physiological parameters. Based on the efflux characteristic, brain tissue could be separated into three portions. The main portion of the derived efflux constant is referred as CBF, where the GM and WM can be differentiated successfully on the CBF map. The other portions may imply the process that D2O distributes into normal water or the secretion of cerebrospinal fluid. Improving the temporal resolution and avoiding the signal drift are essential work in following studies to recognize dynamics of D2O.
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