Multiphasic helical computed tomography predicts subsequent development of severe brain edema in acute ischemic stroke.

OBJECTIVE: To evaluate the use of multiphasic helical computed tomography (CT) in predicting subsequent development of severe brain edema in patients with acute middle cerebral artery (MCA) stroke.
DESIGN: Case-control study.
SETTING: Tertiary referral hospital. PATIENTS: We studied 31 patients with acute MCA stroke who had a baseline National Institutes of Health Stroke Scale score of 15 or higher within 6 hours of symptom onset. Sequential 4-phasic enhanced helical CT scans were performed after taking precontrast CT scans. The severity of perfusion deficit was graded as "severe" or "moderate" depending on collateral blood flow. MAIN OUTCOME MEASURES: Patients were classified as having severe brain edema if they showed signs of uncal herniation or deterioration with mass effect leading to hemicraniectomy.
RESULTS: Severe brain edema developed in 10 patients (32%). Severe perfusion deficit greater than 50% of the presumed MCA territory on multiphasic helical CT was more often found in patients with severe brain edema than in those without (8 of 10 vs 4 of 21, P =.002). In contrast, parenchymal hypodensity greater than 50% on precontrast CT was observed only in 5 patients with severe brain edema (5 of 10 vs 4 of 21, P =.10). Additional involvement of the anterior or posterior cerebral artery territory was found on multiphasic CT (6 of 10 vs 0 of 21, P <.001) and on precontrast CT (4 of 10 vs 0 of 21, P =.007) only in patients with severe brain edema.
CONCLUSION: Multiphasic helical CT is more useful than precontrast CT for predicting subsequent severe brain edema in acute MCA stroke based on the findings of severe perfusion deficit greater than 50% of the MCA territory and additional involvement of the anterior or posterior cerebral artery territory.