ABSTRACT
<p><b>OBJECTIVE</b>To determine the optimal parameters and their thresholds on CT perfusion (CTP) to predict the penumbra and core in patients with acute ischemic stroke.</p><p><b>METHODS</b>The data of 39 thrombolytic candidates with acute cerebral anterior-circulation ischemic stroke admitted in the Second Affiliated Hospital, Zhejiang University School of Medicine from June 2009 to October 2013 were retrospectively reviewed. Patients all underwent CTP at admission and CTP or magnetic resonance perfusion (MRP) 24 h after thrombolysis. Patients were classified as non-reperfusion group (to define the threshold of penumbra, n=10) and reperfusion group (to define the threshold of infarct core, n=21) by reperfusion status. According to the baseline CTP and 24 h imaging, the volumes of threshold-based hypoperfusion lesions and final infarction were calculated. Paired t test, correlation analysis and Bland-Altman plot were performed to assess the optimal thresholds for predicting the penumbra and infarct core.</p><p><b>RESULTS</b>In non-reperfusion group, the best agreement was found between final infarct volume and delay time>3 s (bias 3.3 ml, 95% limits of agreement:-41.7 to 48.3 ml, r=0.933, P<0.001), while in reperfusion group, the best agreement was noted between final infarct volume and rCBF<30% (bias -2.2 ml, 95% limits of agreement:-25.6 to 21.2 ml; r=0.923, P<0.001).</p><p><b>CONCLUSION</b>Delay time>3 s and rCBF<30% are the optimal thresholds for predicting the penumbra and infarct core on CTP, respectively. These thresholds may be of help to estimate the mismatch status and select eligible patients for thrombolysis.</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Brain Ischemia , Diagnostic Imaging , Pathology , Retrospective Studies , Stroke , Diagnostic Imaging , Pathology , Tomography, X-Ray ComputedABSTRACT
<p><b>OBJECTIVE</b>To evaluate the collateral flow of patients with acute ischemic stroke by dynamic CT angiography (CTA) and to analyze the relationship between collateral flow and outcome after intravenous thrombolysis.</p><p><b>METHODS</b>We retrospectively analyzed CT perfusion (CTP) imaging of 22 acute ischemic stroke patients with middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion undergoing intravenous thrombolysis, and reconstructed the images for dynamic CTA in the Second Affiliated Hospital, Zhejiang University School of Medicine from June 2009 to October 2013. The total extent and flow speed of collateral flow based on dynamic CTA images of these patients were evaluated. The scores of National Institute of Health stroke scale (NIHSS) in different collateral flows were compared with repeated measuring. The nonparametric Spearman's rank correlation was used to assess the relationship between collateral flow and modified Rankin scale (mRS) at 3 months after thrombolytic therapy.</p><p><b>RESULTS</b>Compared with the poor collateral flow group, patients with good collateral flow had lower NIHSS at 1 month after thrombolysis (4.7±5.0 vs 25.1±15.1, P=0.001) and higher reperfusion percentage (69%±32% vs 23%±54%, P=0.044). The total condition score of collateral flow was positively correlated with mRS at 3 months after treatment (r=0.450, P=0.001).</p><p><b>CONCLUSION</b>Acute ischemic stroke patients with good collateral flow after intravenous thrombolysis have a better outcome. The dynamic CTA can be used to evaluate the collateral flow and to predict clinical outcomes in patients with acute ischemic stroke after thrombolysis therapy.</p>