中文摘要：

目的：采用7．0Tesla磁共振（MRI）T2加权成像（T2WI）结合磁共振波谱分析（MRS）研究大鼠脑缺血后脑皮质水肿情况。方法：SD大鼠40只随机分为假手术组和大脑中动脉缺血（MCAO）1d、3d及7d组，分别于脑缺血后1、3、7d，采用7．0TeslaMRI扫描各组大鼠脑部TzwI序列，检测缺血侧皮质阳性信号体积，单体素点分辨波谱技术（PRESS）测量水峰峰值及峰下面积，干湿重法检测缺血侧皮质含水量。结果：与假手术组相比，缺血后1、3、7d组T。wI显示缺血侧皮质信号明显增高，MRS显示水峰峰值和峰下面积明显升高，脑组织含水量明显增高，均于第3天达到高峰。结论：MRI及MRS技术可用于脑缺血后脑组织水肿的评估．

英文摘要：

Objective： To analyze 7.0 Tesla magnetic resonance Tz weighted image （TzWI） and magnetic resonance spectroscopy （MRS） of cortical edema in rats after middle cerebral artery occlusion （MCAO）. Methods： Forty SD rats were randomly divided into sham group and MCAO ld,3d and 7d groups （n：10, each）. 7.0 Tesla MR scan of the brain was performed at ld,3d and 7d post MCAO respectively. Brain edema volumetric changes were detected using a Tz weighted spin echo multi-slice sequence. The in vivo single voxel spectroscopy（PRESS） data were ob- tained. The cerebral water content was measured by the wet-dry weight method. Results： The signals in TzWI,HzO peaks in MRS and cerebral water contents of MCAO ld,3d and 7d group were significantly higher than those in the sham group （P~0.05）, peaking at the third day post MCAO. Conclusion： MRI and MRS are useful methods to evaluate the brain edema after cerebral ischemia.