联合应用QSM和STI定量监测多发性硬化脑白质病灶动态演变及其成像机制研究

项目名称： 联合应用QSM和STI定量监测多发性硬化脑白质病灶动态演变及其成像机制研究

项目编号： No.81501445

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 医药、卫生

项目作者： 曹玮

作者单位： 华中科技大学

项目金额： 18万元

中文摘要： 多发性硬化是好发于中青年的中枢神经系统炎症脱髓鞘疾病，致残率高。脑白质病灶病理表现复杂多变，为不同程度的炎症反应及脱髓鞘。监测脑白质病灶动态演变对优化治疗策略具有重要意义。然而目前的MRI技术具有相当的局限性。组织学研究表明脑白质病灶内铁和髓鞘的分布与病灶的病理表现存在着密切关系。前期研究证明QSM可以定量反映脑内铁的分布；磁化率张量成像（STI）可以定量检测白质脱髓鞘程度。在此基础上，本项目以EAE小鼠和MS患者为研究对象，采用QSM和STI定量监测脑白质病灶的动态演变过程，通过磁化率及磁化率各向异性的变化定量描述病灶内铁分布和脱髓鞘的变化，从而反映病灶内炎症反应的活动性及髓鞘层的变化；并结合EAE小鼠脑片免疫组织化学及PCR等方法探讨成像机制。这项研究证明磁化率及磁化率各向异性能够作为定量评价多发性硬化病情变化的生物学指标，联合运用QSM和STI是定量监测脑白质病灶动态演变的有效工具。

中文关键词： 磁共振成像；MR磁量图；磁化率张量成像；多发性硬化

英文摘要： Multiple sclerosis (MS) is a common inflammatory demyelinating disorder of the central nervous system in young and middle-aged with the high rate of disability. With the multiplicity and complexity, the pathologic changes in brain white matter lesion are different degree of inflammation and demyelination. Monitoring the dynamic process within white matter lesion in MS is very critical for optimizing the treatment strategy. However conventional MRI techniques are limited to reveal the changes at microscopic level. Histological studies show iron and myelin distribution within white matter lesion are closely associated with the pathology. Our previous studies have shown that quantitative susceptibility mapping (QSM) can reflect brain iron distribution and susceptibility tensor imaging (STI) can reveal demyelination disease. On the basis of the preliminary studies, we will monitor the dynamic process within brain white matter lesion in EAE mice and MS patients with the application of QSM and STI, and describe quantitatively iron distribution and demyelination within white matter lesion through magnetic susceptibility and magnetic susceptibility anisotropy, which may reflect the activity of inflammation and changes of myelin layer. We will also determine the imaging mechanism combined with the methods of immunohistochemistry and PCR in vitro. The current study may provide proof that magnetic susceptibility and magnetic susceptibility anisotropy can be used as the biomarkers for the quantitative evaluation of MS severity, and the combined application of QSM and STI is a useful tool to monitor the dynamic process within white matter lesion in MS.

英文关键词： MRI;quantitative susceptibility mapping;susceptibility tensor imaging;multiple sclerosis