脑梗死前期MR脑灌注成像的表现及其分期

Magnetic Resonance Perfusion Imaging and Stages of RegionalCerebral Perfusion in Pre-infarction Period

目的探讨脑梗死前期MR脑灌注成像表现和分期的临床应用价值,提高对脑梗死前期的诊断水平,预防和减少脑梗死的发生。资料与方法采用MR脑灌注成像,对18例患者的170层脑灌注图像和对照组20例非脑血管病患者的197层脑灌注成像进行分析,计算每层图像的患/健侧比值,并与对照组的正常比值及其范围做比较。以非参数统计方法、多元方差分析和两两比较分析病例组和对照组脑灌注血流动力学参数及其分期。结果病例组和对照组的4个血流动力学参数均有显著性差异(P<0.01)。脑梗死前期分期特征为:Ⅰ1期峰值时间(TTP)稍有延长,Ⅰ2期平均通过时间(MTT)显著延长,Ⅱ1期为局部脑血流量(rCBF)明显下降,Ⅱ2期局部脑血容量(rCBV)下降。结论脑灌注成像可提供脑梗死前期的血流动力学参数变化的信息,并可以其参数变化进行分期。

Objective To discuss clinical value of magnetic resonance （MR） perfusion imaging and stages of regional cerebral perfusion in pre-infaretion period and improve the diagnosis level for pre-infarction period, and prevent or decrease the incidence of cerebral infarction. Materials and Methods 18 cases of cerebral ischemia in ease group and 20 eases of non cerebral ischemia in control group were performed with dynamic enhance perfusion MR. Parameters of blood flow dynamics of 170 images of 18 eases in case group were compared with that of 197 images of 20 cases in control group to calculate the ratios of illness side and mirror image for every image at hypoperfusion areas in the regional cerebral ischemia and compared to normal ratios and their range provided by control group. Comparing analysis of four parameters and stages blood flow dynamics were conducted by methods of nonparametric statistics and multivariate analysis of variance and multiple comparison. Results Four parameters of blood flow dynamics between two groups had a significant difference （ P 〈 0.01 ）. The characters of stages of regional cerebral in pre-infarction period were as follows： stage Ⅰ 1, TTP was delayed slightly; stage Ⅰ 2, MTF was extended markedly; stage Ⅱ 1, rCBF was markedly dropped; stage Ⅱ 2, rCBV was notable decreased. Conclusion The information of regional cerebral perfusion in preinfarction period can be provided by MR cerebral perfusion and stages of prenfarction period can be designated with the change of blood flow dynamics parameters.