探讨陈旧性脑梗死缺血脑区的影像学特点和加压灌注治疗

目的研究低灌注脑缺血区的影像学特点,检验经动脉内加压灌注治疗陈旧性脑梗死的可靠性和疗效,以探讨加压灌注治疗的理论依据。方法利用磁共振灌注成像技术(perfusion weighted imaging,PWI)对45例缺血性脑血管病患者的责任病灶进行局部脑血流量(rCBF),局部脑血容量(rCBV),平均通过时间(MTT)比值测定(患侧/健侧),确定低灌注脑区的影像学特点和缺血分期:代偿期(rCBF保持正常,rCBV升高,MTT延长);失代偿期(rCBF轻度下降,rCBV正常或下降,MTT延长);梗死前期:(rCBF下降,rCBV下降,MTT延长)。结合常规数字减影血管造影术(DSA)进行加压灌注治疗;术后复查PWI,对比相应区域上述血流动力学参数变化,评定治疗效果;根据美国国立卫生研究所脑卒中评分(NIHSS)标准对45例患者治疗前后进行评分。结果45例脑梗死患者经加压灌注治疗后,神经缺损症状均有不同程度的改善,NIHSS中位数由10分降到8分;对比术前和术后的脑灌注磁共振影像,大部分皮质型脑梗死(14/19)、所有分水岭区脑梗死(23/23)血流灌注状态有所好转,2例基底节区脑梗死无效(2/3)。结论脑梗死后长期存在低灌注脑区,DSA结合PWI可以较为准确的评价低灌注脑区的缺血损害程度以及治疗价值,侧支循环的建立是加压灌注治疗能否起效的关键。

Investigation of the image feature of old cerebral infarction and treatment with pressor perfusion

Objectives To analyze the image characteristics of old cerebral infarction,to evaluate the reliability and efficacy of intermittent pressor perfusion by the way of carotid and vertebral arteries and to investigate the rationale of pressor perfusion.Methods Perfusion weighted imaging(PWI) was performed in 45 cases of cerebral infarction.The side-to-side ratios of regional cerebral blood flow(rCBF),regional cerebral blood volume(rCBV) and mean transit time(MMT) were measured at duty lesion of ischemia.The hypoperfused cerebral areas and the stages of ischemia were defined as follows:compensation stage: rCBF was normal,rCBVwas increased,MTT was prolonged;decompensation stage: rCBF was slightly decreased,rCBV was normal or decreased,MTT was prolonged;pre-infarction stage: rCBF and rCBV were decreased,MTT was prolonged.After pressor perfusion therapy, PWI was performed again,then the parameters were compared and therapeutic efficacy was evaluated with NIHSS score.Results After therapy,the neurological deficits were improved to different degrees,median NIHSS score decreased from 10 to 8,the blood perfusion of ischemic area on PWI was markedly increased in 14 cortical infarction cases and all cerebral watershed infarction cases,but not in 2 basal nuclei infarction cases compared with those before therapy.Conclusions Cerebral hypoperfusion exists for long time after cerebral infarction.DSA combined with PWI can evaluate the ischemic degree and therapeutic value.The collateral circulation may play the important role in the therapeutic efficacy.