Early prediction of irreversible brain damage after ischemic stroke at CT

PURPOSE: To assess the capability of computed tomography (CT) in the prediction of irreversible ischemic brain damage and its association with the clinical course within 6 hours of stroke onset. MATERIALS AND METHODS: Serial CT scans obtained within 6 hours of stroke onset, at 22-96 hours (median, 1 day), and at 2-36 days (median, 7 days) after symptom onset in 786 patients with ischemic stroke were prospectively studied, and follow-up CT scans were used as the reference. Clinical variables were assessed prospectively and independently of CT evaluation. RESULTS: The specificity and positive predictive value of ischemic edema at baseline CT for brain infarcts were 85% (95% Cl: 77%, 91%) and 96% (95% Cl: 94%, 98%), respectively. Sensitivity and negative predictive values were 64% (95% Cl: 60%, 67%) and 27% (95% Cl: 23%, 32%), respectively. Patients without early CT findings were less severely affected (P <.001), developed smaller infarcts (P <.001), had fewer intracranial bleeding events (P <.001), and had a better clinical outcome at 90 days (P <.001) compared with patients with hypoattenuating brain tissue at early CT. CONCLUSION: After ischemic stroke, x-ray hypoattenuation at CT is highly specific for irreversible ischemic brain damage if detection occurs within the first 6 hours. Patients without hypoattenuating brain tissue have a more favorable clinical course.