复发缓解型多发性硬化患者看似正常脑白质区脑血流量分析

Reduced perfusion in normal appearing white matter in relapsing-remitting multiple sclerosis using 3D pseudocontinuous arterial spin labeling

目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NAWM)脑血流量(cerebral blood flow,CBF)变化,并分析其临床相关性。材料与方法本研究共纳入29例RRMS患者及年龄性别完全匹配的17名健康志愿者。所有受试者通过GE公司的3.0 T MR采集了T2加权成像(T2weighted image,T2WI)、三维快速扰相梯度回波序列(3-dimensional fast spoiled gradient echo,3D-FSPGR)及3D p CASL。将3D p CASL标准化配准后在半卵圆中心NAWM、侧脑室旁NAWM手绘感兴趣区,得到两个区域的平均CBF值。采用两独立样本t检验比较RRMS和健康志愿者的NAWM CBF值的差异,并将CBF值与临床资料进行相关性分析。结果与健康志愿者比较,RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值明显降低(半卵圆中心NAWM:32.5452±4.5848 vs 35.4865±5.7968,P=0.036;侧脑室旁NAWM:30.7788±4.1746 vs 34.0530±4.4821,P=0.006)。RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值与患者的年龄、发病年龄、发病次数、病程、扩展残疾状态量表(expanded disability status scale,EDSS)评分没有明显相关性。结论采用3D p CASL技术定量分析RRMS患者微循环的脑血流灌注情况发现,在常规MRI没有明显病变的NAWM的CBF值明显降低。该研究表明RRMS患者NAWM存在潜在的血流动力学改变,进一步提示血流动力学因素在RRMS患者的发病中可能起着重要的作用。

Objective： To investigate whether cerebral blood flow （CBF） is abnormal in normal appearing white matter （NAWM） using 3D pseudocontinuous arterial spin labeling （3D pCASL） and its relationship with clinical data. Materials and Methods： Twenty-nine relapsing-remitting MS （RRMS） and seventeen age, sexmatched healthy control subjects were prospectively and consecutively enrolled and performed MRI including T2 weighted image （T2WI）, 3-dimensional Fast Spoiled Gradient Echo （3D FSPGR） and 3D pCASL. Regions of interest （ROls） in centrum semiovale and periventricular NAWM were manually outlined to obtain the average CBF values. Two independent samples t-test was conducted for comparisons between RRMS and healthy control group in centrum semiovale and periventricular NAWM.Person and Spearman correlation analysis were used to assess the relation between clinical data and CBF values for RRMS group. Results： Compared to healthy control subjects, CBF values were significantly reduced both in centrum semiovale and periventricular NAWM in RRMS （centrum semiovale NAWM： 32.5452±4.5848 vs 35.4865±5.7968, P=0.036; periventricular NAWM： 30.7788±4.1746 vs 34.0530±4.4821, P=0.006）. In RRMS group, no relationships were found between CBF values and clinical data （age, age of first onset, onset frequency, disease duration and EDSS score）. Conclusion： Our 3D pCASL results showed reduced perfusion in NAWM in RRMS group indicating that there exists potential hemodynamic abnormality in NAWM and hemodynamics may be play a pivotal role in pathogenesis of RRMS patients.