Background: The efficacy of endovascular therapy (EVT) in acute stroke has been established but the imaging criteria have not yet been assessed. Malignant profile is a magnetic resonance imaging (MRI) pattern that is associated with poor outcomes. We estimated this profile by volumetrically assessing diffusion weighted image (DWI) in patients treated with reperfusion therapy including intravenous tissue plasminogen activator (IV tPA) and endovascular therapy (EVT).
Methods: Acute anterior ischemic stroke patients with baseline DWI before reperfusion therapy were included. Outcome was assessed by modified Rankin Scale (mRS) at discharge. DWI volume was measured by semi-automated software.Receiver operating characteristic (ROC) curve analysis was performed to identify optimal DWI volumes with poor outcome (mRS 5-6).
Results: Total of 96 patients (43% women, mean age 72±13 years) were included in this study. Median (interquartile range: IQR) National Institutes of Health Stroke Scale was 9 (5-12) and median onset to MRI time was 108.5 (70-217) minutes. Median DWI volume was 4.4 (1.3-17) mL for overall patients. Median onset to IV tPA time for 60 (63%) patients were 120 (65-177) minutes. Median onset to puncture time for 36 (38%) EVT-treated patients was 208 (121.0-474.3) minutes; 29 of these 36 patients (81%) had Thrombolysis in Cerebral Infarction (TICI) score of 2B/3. Median discharge mRS was 2 (1-3) for overall and 6 cases (6%) had mRS 5-6. ROC analysis determined DWI volume with poor outcome as 49.5 mL (92.2% specificity and 50% sensitivity, AUC 0.75, p<0.001).
Conclusion: Our study suggests the optimal volume of the malignant profile on DWI was approximately 50mL in reperfusion therapy eligible patients. Clinical outcome of patients exceeding the cutoff volume were very poor. The imaging criteria for reperfusion therapy including EVT should be well considered to achieve better outcomes.