基于功能磁共振成像技术的模拟失重下的脑灌注及代谢研究

发布时间：2018-04-21 14:07

本文选题：飞行员 + 模拟轻度失重　；参考：《南京航空航天大学》2017年硕士论文

【摘要】：在正常飞行过程中,飞行员经常会处于轻度失重状态。相对重度失重引起的眩晕及红视等问题,轻度失重问题长期被忽视。当人处于失重状态时,因为流体静水压差消失血流向头部转移,所以可以导致脑的灌注和代谢改变,进而影响到脑的生理功能。飞行员长期在失重情况下,会对其健康和任务的执行产生很大影响。因此,研究失重对脑灌注和代谢的影响非常重要。本文重点研究了人体在模拟轻度失重条件下的脑血流和脑氧代谢率的变化机制。首先,为模拟飞行员轻度失重状态,本研究采用了-10°头低位的方式,并采用倾斜前后对比研究轻度失重对脑血流动力学和代谢的影响;其次,为无损检测脑血流动力学和代谢指标,本研究采用基于动脉自旋标记和T2弛豫自旋标记技术的磁共振成像技术的灌注及代谢成像技术,有效和可靠地测量脑血流和脑氧代谢率;再次,通过倾斜前后,脑血流和脑氧代谢的改变,研究了人脑在经受失重环境下的变化机制及其影响;最后,实验结果显示脑血流发生显著性改变的脑区有中央前回、中央后回、顶叶、额叶、楔前叶,扣带回等脑区,全脑的静脉血氧饱和度下降,脑氧代谢率升高。这些脑区如果长时间充血,其功能可能也会受到影响。本研究发现,轻度失重可以对飞行员的脑灌注和代谢产生影响。本研究所采用成像技术为无损的功能磁共振技术,可以为飞行员脑健康评估提供客观评价指标。
[Abstract]:During normal flight, pilots are often in mild weightlessness. Relative severe weightlessness caused by vertigo and red vision problems, mild weightlessness has been ignored for a long time. When people are in weightlessness, the hydrostatic pressure difference disappears and the blood flow transfers to the head, which can lead to the changes of brain perfusion and metabolism, and then affect the physiological function of the brain. Long-term weightlessness affects pilots' health and mission performance. Therefore, it is important to study the effects of weightlessness on cerebral perfusion and metabolism. This paper focuses on the mechanism of cerebral blood flow and cerebral oxygen metabolism rate under simulated mild weightlessness. First, in order to simulate the pilot's mild weightlessness, the study adopted the method of -10 掳head-down, and compared the effects of mild weightlessness on cerebral hemodynamics and metabolism before and after tilt. In order to detect cerebral hemodynamics and metabolism, perfusion and metabolic imaging based on arterial spin labeling and T2 relaxation spin labeling were used to measure cerebral blood flow and cerebral oxygen metabolism rate effectively and reliably. Thirdly, through the changes of cerebral blood flow and cerebral oxygen metabolism before and after tilt, we studied the mechanism of brain changes and their effects under weightlessness. Finally, the experimental results showed that there were precentral gyrus in brain regions with significant changes in cerebral blood flow. After central gyrus, parietal lobe, frontal lobe, prewedge lobe, cingulate gyrus, cerebral venous oxygen saturation decreased and cerebral oxygen metabolism rate increased. These areas may also be affected if they are congested for long periods of time. This study found that mild weightlessness may have an effect on brain perfusion and metabolism in pilots. The imaging technique used in this study is a nondestructive functional magnetic resonance (fMRI) technique, which can be used to evaluate the brain health of pilots.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R852.22

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