Reduced rCBV ratio in perfusion-weighted MR images predicts poor outcome after thrombolysis in acute ischemic stroke

Abstract

Recent research has suggested that a perfusion-weighted image (PWI) relative cerebral blood volume (rCBV) map after acute ischemic stroke (AIS) provides information about the collateral circulation in the ischemic region. In this study, we demonstrate the usefulness of the rCBV ratio in PWI in predicting poor outcome after using IV t-PA in AIS. We recruited 58 stroke patients who were treated with IV t-PA after diagnostic magnetic resonance imaging (MRI). Poor outcome was defined as a Modified Rankin Scale (mRS) score >2 measured 90 days after ischemic insult. In total, 21 patients (36.2%) demonstrated poor outcome (i.e. mRS score 3-6). Poor outcome after t-PA correlated with age (p = 0.03), serum glucose level (p = 0.01), NIHSS (p = 0.05), and the presence of T-occlusion (p = 0.05). Poor outcome also correlated with diffusion-weighted MR images of the lesion volume (p < 0.01), lower rCBV ratio on PWI (p < 0.01), and non-recanalization (p < 0.01). Among these, non-recanalization (p < 0.01), reduced rCBV ratio on PWI (p < 0.01), age (p = 0.04), and serum glucose level (p = 0.01) had an independent significance for predicting it. This suggests that the rCBV ratio on PWI may be used to determine prognosis after thrombolysis in AIS.