急性缺血性脑卒中患者脑灌注改变与可能干预靶点

目的观察急性缺血性脑卒中患者病灶区与病灶周围区灌注参数的变化,探讨可能干预治疗的作用靶点。方法选择2015-03—2016-03连续入组的发病时间在72h以内急性缺血性脑卒中住院患者,入院后24~48h内行磁共振灌注检查,灌注参数包括脑血容量(CBV)、脑血流量(CBF)、平均通过时间(MTT)和达峰时间(TTP)。应用视觉评定法判断是否存在灌注异常将患者分为灌注正常组和异常组;采用图像融合技术和同心圆定标法确定位于病灶区和病灶周围区的兴趣区(ROI)和其镜像区(ROM),自动计算ROI、ROM信号值;以ROI/ROM作为灌注参数相对值即rCBV、rCBF、rMTT、rTTP进行比较。结果共入组患者158例,灌注异常113例,灌注正常45例,异常率72%。与灌注正常组比较,无论病灶区还是病灶周围区,灌注异常组患者均表现为rCBV升高(CBV与信号值成反比)、rCBF减少、rMTT和rTTP延长,与灌注正常组差异有统计学意义(P0.01)。在灌注异常组患者病灶区和病灶周围区CBV减少存在低灌注;MTT和TTP延长存在血流淤滞;而灌注正常组患者则表现为CBV增加出现高灌注;MTT和TTP正常,无明显血流淤滞。改善灌注异常组患者病灶和病灶周围区CBV成为临床干预治疗的可能靶点。结论改善病灶区和其周围区域的CBV,为急性缺血性脑卒中患者的临床治疗提供了可能的治疗靶点和客观判断标准。

Changes of cerebral reperfusion and potential targets for intervention in acute ischemic stroke

Objective To observe the changes of cerebral perfusion parameters in ischemic lesion and its surrounding area, and to explore the possible targets for clinical intervention in acute ischemic stroke.Methods Consecutive in-patients with acute ischemic stroke with less than 72 hours of symptom onset from March 2015 to March 2016 were enrolled and all patients received magnetic resonance perfusion weighted imaging within 24 to 48 hours after being admitted to hospital.Cerebral perfusion parame-ters includedcerebral blood volume (CBV),cerebral blood flow (CBF),mean transit time (MTT)and time to peak (TTP).All pa-tients were divided into normal perfusion group and abnormal perfusion group according to the result of visual assessment.Image fusion technique and concentric circle calibration method were used to localize the region of interest (ROI)and itsmirror of interest (ROM)and then the values of them were automatically calculated.ROI/ROM (rCBV,rCBF,rMTT,rTTP)regarded as relative value was compared.Results Of the included 158 cases,113 cases presented abnormal perfusion and 45 casespresented normal perfusion diagnosed by visual assessment,with an abnormal perfusion rate of 72%.Either ischemic lesion or its surrounding area showed increase of rCBV,reduction of rCBF and extension of both rMTT and rTTP in the abnormal perfusion group,all of which displayed statistical differences compared with the normal perfusion group (all P<0.01).It suggested that hypo-perfusion existed in ischemic lesion or its surrounding area in the abnormal perfusion group because of the reduction of CBV and blood stasis oc-curreddue to the extension of both MTT and TTP.Conversely,the normal perfusion grouppresented hyper-perfusion and no obvi-ous stasis.As a result,improvement of CBV inischemic lesion or its surrounding area might become a possible target for clinical in-tervention.Conclusion Improving CBV in ischemic lesion or its surrounding area may be a possible target for clinical intervention and a promising criterion of obj ective j udgment for clinical treatment.