Prognostic value of hyperattenuating middle cerebral artery sign at CT in cerebral infarction

PURPOSE: To assess the prognostic value of hyperattenuating middle cerebral artery sign at CT in acute cerebral infarction. MATERIALS AND METHODS: Ninety-two patients with acute cerebral infarction in the sylvian area were retrospectively reviewed. All patients underwent unenhanced CT 12-24 hours after the onset of symptoms and follow-up CT within 48-72 hours. Initial CT scans were evaluated by consensus by three radiologists to confirm or exclude the presence of hyperattenuating middle cerebral artery sign. History, cardiovascular risk factors and neurological impairment at discharge (mean 25 days) were recorded for each patient. The degree of disability was graded 0 (no disability) to 6 (death). Patients were divided into two groups: patients without (group A) and patients with (group B) hyperattenuating middle cerebral artery sign. A logistic regression analysis was performed to compare the two groups. Results were correlated with cardiovascular risk factors. Kaplan-Meier survival curves were calculated for each group. RESULTS: Hyperattenuating middle cerebral artery sign was present in 18 patients (19.6%) (group B). The percentage of neurological deficits was significantly higher in group B than in group A (p<0.05). Sixteen (88.9%) of the 18 patients in group B had a poor prognostic index (score 3 - 6) with a significantly higher percent difference (41.6%, p<0.05) than patients of group A. Within 10 days of admission, 3 patients (16.7%) died in group A and 6 (8.1%) in group B. However, no significant differences were observed in the Kaplan-Meier survival curves. No correlation with cardiovascular risk factors was observed. CONCLUSIONS: Besides having an important diagnostic value, hyperattenuating middle cerebral artery sign is a reliable predictor of prognosis in terms of disability rather than mortality, as it reflect the larger extension of infarction.