Signifiance of brush sign on susceptibility-weighted imaging predicts hemorrhagic transformation after intravenous thrombolysis in patients with acute ischemic stroke

Abstract

To assess brush sign (BS) on susceptibility-weighted imaging (SWI) in prediction of hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) after intravenous thrombolysis(IVT). Patients with acute cerebral ischemic stroke, who had major cerebral artery occlusion (internal carotid artery, middle cerebral artery M1 and M2), treated with intravenous recombinant tissue plasminogen activator (rt-PA) from August 2009 to October 2014 in the Second Affiliated Hospital, Zhejiang University School of Medicine, were enrolled in the study. All patients underwent SWI scanning. The asymmetry index (AI) was defined as the difference of intensity between ischemic and normal hemispheres on the SWI phase map; according to AI values patients were divided into 3 groups: BS=0(n=9), BS=1 (n=39) and BS=2 (n=18). The relationships between BS and HT and the clinical outcome among the 3 groups were analyzed. Sixty-six patients aged 68 ± 13 years were included in the study, including 44 males (67%) and 22 females (33%), and 44 (67%) with acute ischemic stroke. The mean pre-treatment National Institutes of Health Stroke Scale (NIHSS) score was 13 (6-17), and the onset to needle time was (252 ± 88) min. Twenty-six (39.4%) patients had HT, including 18 cases (27.3%) with HI and 8 cases (12.1%) with PH; BS was observed more frequently in HT group than non-HT group. Binary logistic regression analysis showed that BS was independently associated with HT of patients with acute ischemic stroke following IVT (OR=2.589, 95% CI: 1.080-6.210, P=0.033). In those without reperfusion after IVT, patients with higher BS grade had higher HT rate (P=0.023). Brush sign on SWI can be used for predicting hemorrhagic transformation after intravenous thrombolysis in patients with acute ischemic stroke.