脑缺血动物模型的脑氧摄取分数MRI定量分析及后处理优化研究

项目名称： 脑缺血动物模型的脑氧摄取分数MRI定量分析及后处理优化研究

项目编号： No.81201154

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 影像医学与生物医学工程

项目作者： 谢晟

作者单位： 中日友好医院

项目金额： 23万元

中文摘要： 脑血管病目前排在人类致残性疾病的首位。脑氧摄取分数（OEF）增高可以作为一个预示发生卒中的独立危险因素，有较大的临床应用价值。目前检测OEF的方法只有PET，在临床上难以普及。我们通过研究，设计了GESSE序列，可以通过数学模型计算OEF，从而实现了利用MRI无创测量OEF，并进一步开发了快速序列ASE。但是数学模型本身仍待改进，并且病理条件下测量的准确性还有待验证。本课题在以往工作的基础上，通过犬脑低灌注及高灌注模型，以经同步血气分析计算出的OEF为标准，验证在病理条件下定量检测OEF的准确性；同时拟将现代信号处理技术融合到OEF测量中，应用频域分析等方法，改进优化数学模型；以犬脑梗塞模型的病理学观测结果为依据，确立OEF变化与组织学变化的关系，探讨OEF在缺血性脑卒中的预测作用。本课题将为脑血流动力学的测量提供新方法，并进一步为OEF的临床应用提供理论依据和技术支持。

中文关键词： 磁共振成像；氧摄取分数；脑缺血；；

英文摘要： Cerebral vascular disease is now the leading cause of disability in human kind. The presence of increased oxygen extraction fraction (OEF) has been proven to be a powerful and independent risk factor for subsequent stroke. Positron emission tomography remained the only way for measurement of OEF, but the high cost and limited availability inhibited its clinical use. We have worked out gradient echo sampling spin echo sequence (GESSE), which proved to be a noninvasive MR technique to estimate OEF quantitatively on an analytical model. We further investigated a more efficient sequence named asymmetric SE-EPI (ASE). However, the analytical model needs to be improved, and its accuracy under the pathological conditions needs to be tested as well. By using animal models with cerebral hypoperfusion and hyperperfusion, this project is designed to test the accuracy of OEF measurement with the standard results of blood gas analysis. Meanwhile, the estimation of OEF will be improved by optimizing the analytical model with modern signal processing technology. Based on the pathological results of canine infarct models, the correlation between OEF and pathological changes will be established to define the predictive value of OEF in the stroke. In conclusion, our project will provide a new method to evaluate brain hemodynamic,

英文关键词： magnetic resonance imaging；oxygen extraction fraction；cerebral ischemia；；