急性脑缺血兔磁共振弥散加权成像和灌注加权成像与神经功能缺损的关系

目的研究急性脑缺血兔的弥散加权成像（DWI）及灌注加权成像（PWI）的特点,探讨其与神经功能缺损之间的关系。方法取成年雄性新西兰兔30只,制作大脑中动脉急性脑缺血损伤模型;造模成功后6 h采用Purdy评分评价神经功能损害程度;行MRI DWI和PWI检查,计算DWI高信号区和PWI的脑血流量图（CBF）低灌注区的体积,分析异常信号区体积与神经缺损评分之间的相关性。结果脑缺血兔的CBF低灌注区体积为（91.89±51.31）mm3,DWI高信号区体积为（70.90±43.77）mm3,CBF低灌注区体积大于DWI高信号区,CBF-DWI不匹配区体积为（21.99±16.29）mm3。DWI高信号区和CBF图低灌注区体积均与神经缺损评分呈正相关,CBF-DWI不匹配区体积与神经缺损评分无显著相关性。结论 DWI高信号区与PWI的CBF低灌注区的体积能够反映急性脑缺血兔的神经功能缺损程度。

The relationship of diffusion-and perfusion-weighted imaging to neurological deficits in acute focal cerebral ischemia rabbits

Objective To investigate the feature of diffusion-and perfusion-weighted imaging（DWI and PWI） and its relation to neurological deficit in acute focal cerebral ischemia rabbits.Methods A total of 30 adult male New Zealand rabbits were selected,and the acute focal cerebral ischemia models in middle cerebral artery were prepared.All rabbits were assessed of neurological deficit severity by Purdy score 6 h after successful modeling.After that,they underwent DWI and PWI with MRI,and the DWI high signal volume and the hypoperfusion volume of cerebral blood flow（CBF） on the PWI were calculated separately.Finally,the correlation was analyzed between the volume of abnormal signal region and the Purdy score.Results The hypoperfusion volume of CBF was 91.89 ± 51.31 mm3 and the DWI high signal volume was 70.90 ± 43.77 mm3.The former was larger than the later in all the rabbits,and the CBF-DWI mismatch volume was 21.99 ± 16.29 mm3.There was a significant positive correlation between both the CBF hypoperfusion volume and the DWI high signal volume and the neurological deficit score,while the CBF-DWI mismatch volume did not correlate with the Purdy score.Conclusions The CBF hypoperfusion volume and the DWI high signal volume can reflect the extent of the neurological deficit in the rabbits with acute focal cerebral ischemia.