急性缺血性脑梗死头颅CT灌注参数与侧支循环分级的相关性分析

目的探讨2种头颅CT灌注（CTP）参数阈值法下的急性脑梗死病例梗死核心、缺血半暗带体积及错配率与侧支循环分级间的关系。方法收集发病时间24 h内急性缺血性脑梗死48例，所有病例CTP存在灌注不足且CT血管造影（CTA）提示一侧颈内动脉或大脑中动脉狭窄或闭塞，根据CTA将侧支循环分为良好、一般及不良3个级别，分别使用2种CTP阈值法，Tmax-rCBF法（Tmax>6 s定义低灌注区，rCBF < 30%定义梗死核心）及rMTT-CBV法（rMTT>145%定义低灌注区，CBV < 2 mg/100 g定义梗死核心），测量梗死核心、缺血半暗带体积并计算错配率，并比较上述结果与侧支循环分级的相关性。结果2种阈值法所测得的梗死核心体积与侧支分级呈负相关，缺血半暗带体积及错配率与侧支分级呈正相关（P < 0.01），并且Tmax-rCBF法（r_半暗带=0.796/r_错配率=0.880）缺血半暗带体积及错配率较rMTT-CBV法（r_半暗带=0.601/r_错配率=0.737）与侧支分级相关性更强。结论侧支循环优良与梗死核心、缺血半暗带体积及错配率密切相关，且Tmax-rCBF阈值法定义的缺血半暗带体积及错配率与侧支循环分级相关性更好。

Correlation analysis between CT perfusion parameters and collateral circulation grade in acute ischemic cerebral infarction

ObjectiveTo investigate the relationship between infarct core, ischemic penumbra volume and mismatch ratio by parameter threshold method in two methods CT perfusion(CTP) parameter threshold, and collateral grading in acute cerebral infarction cases.MethodsForty-eight patients with acute ischemic cerebral infarction within 24 hours of onset were collected, and the cerebral CTP deficiency and CT angiography(CTA) confirming lateral internal carotid artery or middle cerebral artery occlusion in all cases were analyzed.According to the results of CTA, the collateral circulation was classified into the good, normal and bad grades.The volume of infarct core and ischemic penumbra, and mismatch ratio were explored using two CTP threshold methods the Tmax-rCBF(Tmax>6 s defined as hypoperfusion area, rCBF < 30% defined as infarct core) and rMTT-CBV(rMTT>145% defined as hypoperfusion area, CBV < 2 mg/100 g defined as infarct core).The correlation between the above results with collateral grading was analyzed.ResultsThe results of two threshold methods showed that the volume of infarct core was negatively correlated with the collateral grading, while the volume of ischemic penumbra and mismatch ratio were positively correlated with the collateral grading(P < 0.01).Moreover, the correlation between the ischemic penumbra volume and mismatch ratio measured by Tmax-rCBF(r_penumbra=0.796/r_{mismatch ratio}=0.880) and collateral grading was better than that by rMTT-CBV(r_penumbra=0.601/r_{mismatch ratio}=0.737).ConclusionsThe good collateral cirulation is significantly related to the volume of infarct core, ischemic penumbra and mismatch ratio, and the correlation of ischemic penumbra volume with mismatch ratio of ischemic defined by Tmax-rCBF is better than that of rMTT-CBV.