Malignant middle cerebral artery infarction in hyperacute ischemic stroke: evaluation with multiphasic perfusion computed tomography maps.

OBJECTIVE

The purpose of this study was to compare the incidence of large hypoperfusion (greater than two-thirds of MCA territory) on computed tomography (CT) perfusion maps between hyperacute middle cerebral artery (MCA) stroke patients without or with malignant cerebral edema.

METHODS

Twenty-seven patients diagnosed with a hyperacute MCA stroke who had an initial National Institutes of Health Stroke Scale (NIHSS) score greater than 10 were included. Multiphasic perfusion CT was performed within 6 hours of symptom onset. Patients were divided into 2 groups: the malignant group (n = 11), composed of patients who died within 7 days, and the nonmalignant group, which included all other patients (n = 16). Unenhanced CT and CT perfusion maps were assessed and compared between the 2 groups with special emphasis on examining the CT findings, including hyperdense MCA sign, large (greater than two-thirds) hypoattenuation and hypoperfusion in the MCA territory, and hypoattenuation in the basal ganglia and other vascular territories.

RESULTS

The incidence of large hypoattenuation (greater than two-thirds of MCA territory) on unenhanced CT and large hypoperfusion on CT perfusion maps differed significantly between the 2 groups (P < 0.05). Large hypoperfusion on the CT total perfusion map was most accurate (93%) among various CT findings for the prediction of malignant MCA infarction with high sensitivity (91%), specificity (94%), and positive predictive value (91%).

CONCLUSIONS

The incidence of large hypoperfusion on a CT perfusion map was higher in the malignant group than the nonmalignant group. CT perfusion maps may provide added information about cerebral perfusion and could be a useful predictor of malignant MCA infarction.