脑梗死前期MR脑灌注成像的临床意义

Correlation analysis of magnetic resonance perfusion imaging and its stages of regional cerebral hypoperfusion in pre-infarction period

目的探讨脑梗死前期MR脑灌注成像的表现和分期临床应用价值。方法采用脑MR灌注成像对18例脑血管病患者的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)。TTP(tim e to peak)和MTT(m ean transit tim e)与发病的相关系数较高,分别为0.422和0.371,rCBV(regional cerebral b loodvolum e)和rCBF(regional cerebral b lood flow)较低,且为负值。脑梗死前期分期特征为:I1期TTP稍有延长,I2期MTT显著延长,Ⅱ1期rCBF明显下降,Ⅱ2期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,并可以对其参数变化进行分期。

Ojective To explore clinical value of application to magnetic resonance （MR） perfusion imaging and stages of regional cerebral hypoperfusion in pre-infaretion period and improve the diagnosis level for pre-infaretion period, and prevent or deerease the inci dence of cerebral infaretion. Methods 18 eases of cerebral isehemia in ease group and 20 eases of non-cerebral isehemia in control group were performed with dynamic perfusion MR 170 MR images of ease group were compared with 197 images of control group, ealeulating the ratios of illness side to normal for every image at hypoperfusion areas in the regional cerebral ischemia and referring and comparing their range provided by control group with methods of nonparametric statistics and multivariate analysis of variance and multiple comparison. Results Four parameters of blood flow dynamics between two groups showed a significant difference（ P〈 0. 01 ）. Correlation coefficients between time to peak （TTP） and time to peak （MTT） and incidence of regional eereberal hypoperfusion in pro-infarction period were higher, 0.422 and 0. 371 respectively, but regional cerebral blood volume （rCBV） and regional cerebral blood flow （CBF） were lower, and also negative. The eharaeters ef stages of regional cerebral hypoperfusion in pre-irffaretion period were as follows ： Stage I1, TTP delayed slightly ; stage I2, MTT extended markedly; stage Ⅱ1, rCBF dropped significantly; stage Ⅱ2, rCBV decreased. Conclusions The information of regionat cerebral bypoperfusion in pre-infarction period might be provided by MR cerebral perfasion and stages of pre-infarction period could be designated with the change of blood flow dynamics parameters.