磁共振成像评估大面积脑梗死慢性期患者预后的临床价值

Clinical value of magnetic resonance imaging in evaluating the prognosis of patients with chronic large hemispheric infarction

目的探讨磁共振成像(MRI)在大面积脑梗死(LHI)慢性期患者预后评估中的价值。方法选择2015年3月至2019年3月开封市中心医院收治的首次发病的LHI患者81例为观察对象。患者均于脑梗死发病后10~15 h首次行MRI检查,证实为单侧急性LHI,患侧靶血管重度狭窄或闭塞。采用抗凝+扩血管+改善微循环等治疗,并于慢性期(发病后16~18 d)复查常规MRI、弥散加权成像(DWI)、磁共振血管成像(MRA)、动态磁敏感对比增强灌注成像(DSC-PWI)、增强MRI检查。根据患者LHI区与健侧对照区的磁共振灌注成像参数值的比值计算相对脑血流量(r CBF)、相对脑血容量(r CBV)、相对平均通过时间(r MTT)和相对达峰时间(r TTP)。根据LHI慢性期DSC-PWI表现将81例患者分为低灌注组(n=47)和高灌注组(n=34),比较2组患者脑梗死区的DSC-PWI表现、治疗前后靶血管变化、美国国立卫生研究院率中量表(NIHSS)评分及慢性期介入治疗情况。结果81例LHI慢性期患者中高灌注34例,低灌注47例。与低灌注组比较,高灌注组患者的梗死区r CBF、r CBV显著增高(P<0.01),r MTT、r TTP显著降低(P<0.05)。高灌注组患者中靶血管改善30例(88.2%),无明显改善4例(11.8%);低灌注组患者中靶血管改善11例(23.4%),无明显改善36例(76.6%);高灌注组患者靶血管改善率显著高于低灌注组(χ^2=33.173,P<0.01)。高、低灌注组患者入院当日NIHSS评分比较差异无统计学意义(P>0.05),高灌注组患者慢性期NIHSS评分显著低于入院时(P<0.05),低灌注组患者慢性期NIHSS评分与入院时比较差异无统计学意义(P>0.05),高灌注组患者慢性期NIHSS评分显著低于低灌注组(P<0.05)。低灌注组患者慢性期磁共振评估后行球囊扩张术或者裸支架植入术19例(40.4%),高灌注组患者均未行介入治疗。结论MRI能评估LHI慢性期患者的脑血流灌注、侧支循环代偿能力及靶血管治疗效果,为临床后期合理治疗提供依据。

Objective To discuss the value of magnetic resonance imaging(MRI)in evaluating the prognosis of patients with chronic large hemispheric infarction(LHI).Methods A total of 81 patients with first onset of LHI admitted to the Central Hospital of Kaifeng City from March 2015 to March 2019 were selected as subjects for observation,which were confirmed to be one-sided acute LHI with severe stenosis or occlusion of target blood vessels at 10-15 hours after cerebral infarction by MRI for the first time.All patients were given the same treatment such as anticoagulation,expansion of blood vessel,improving microcirculation and so on.Routine MRI、diffusion weighted imaging(DWI),magnetic resonance angiography(MRA),dynamic magnetic-sensitive contrast-enhanced perfusion imaging(DSC-PWI),and contrast-enhanced MRI scan were performed to81 patients with LHI in chronic phase(16-18 days after cerebral infarction).Relative cerebral blood flow(r CBF),relative cerebral blood volume(r CBV),relative mean passage time(r MTT)and relative peak arrival time(r TTP)were calculated based on the ratio of the parameters of magnetic resonance perfusion imaging(PWI)between the patient’s LHI region and the control region.According to the chronic DSC-PWI of LHI,81 patients were divided into the low perfusion group(n=47)and the high perfusion group(n=34),and the DSC-PWI of cerebral infarction area,the changes of target blood vessels before and after treatment,the national institutes of health stroke scale(NIHSS)score and the chronic interventional treatment were compared between the two groups.Results There were 34 cases with high perfusion and 47 cases with low perfusion among the 81 cases of patients with chronic-phase LHI.Compared with the low perfusion group,r CBF and r CBV of the infarction area in the high perfusion were higher(P<0.01).r MTT、r TTP of the infarction area in the high perfusion were lower(P<0.05).In the hyperperfusion group,there were 30 patients(88.2%)with target vascular improvement,and no significant improvement in 4 patients(11.8%).In the low perfusion group,target vascular improvement was observed in 11 patients(23.4%),while no significant improvement was observed in 36 patients(76.6%).The target vascular improvement rate in the high perfusion group was significantly higher than that in the low perfusion group(χ^2=33.173,P<0.01).There was no significant difference in the NIHSS score between the low perfusion group and the high perfusion group on the day of admission(P>0.05).The NIHSS score of the high perfusion group in the chronic stage was significantly lower than that of the low perfusion group at admission(P<0.05);the NIHSS score of the low perfusion group in the chronic stage was not significantly different from that of the low perfusion group at admission(P>0.05);the NIHSS score of the high perfusion group in the chronic stage was significantly lower than that of the low perfusion group(P<0.05).Balloon dilatation or bare-stent implantation were performed in 19 patients(40.4%)with low perfusion in the chronic stage after MRI evaluation,but no interventional therapy was performed in all patients with high perfusion.Conclusions MRI can evaluate blood flow perfusion,collateral circulation compensation ability and treatment effect of target vascular in large area cerebral infarction in chronic phase,which can provide important basis for clinic to make reasonable treatment.