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.