Predicting Transformation to Type 2 Parenchymal Hematoma in Acute Ischemic Stroke by CT Permeability Imaging

摘要

I read with great interest the retrospective study by Hom et al,1 in which a model combining clinical metrics with blood-brain barrier (BBB) permeability data from dynamic CT was presented to predict symptomatic hemorrhagic transformation (HT) and malignant edema in acute ischemic stroke. The authors stated that HT was classified according to the convention of the European Cooperative Acute Stroke Study (ECASS II), of which there are 4 subtypes2: hemorrhagic infarction types 1 and 2 (HI1 and HI2) and parenchymal hematoma types 1 and 2 (PH1 and PH2). It was shown in ECASS II that PH2, defined as a space-occupying hematoma of >30% of the infarct zone with substantial mass effect attributable to the hematoma, is the only subtype of HT that portends poor prognosis.3 HI's, on the other hand, are defined as petechial hemorrhages without mass effect and are likely epiphenomenal, reflecting reperfusion into the infarct. (For examples of the 4 HT subtypes by ECASS criteria, see Berger et al.3)