The Research Of Multi-modality MRI-based Intravenous Thrombolysis Therapy For Patients With Acute Ischemic Stroke

PartⅠ The Value of DWI-FLAIR mismatch in the evaulation of thrombolysis therapy for patients with ischemic stroke within 4.5-6h of symptom onsetPurpose: By comparing the outcomes of thrombolysis therapy in different patients with ischemic stroke of the time since symptom onset and influid-attenuated inversion recovery(FLAIR) singal intensity,This study aimed to evaluate the value of DWI-FLAIR mismatch in thrombolysis therapy for patients with ischenmic stroke within 4.5-6h of symptom onset.Material and Methods: Data of 105 ischemic stroke patients who received thrombolysis therapy were collected. Patients were allocated to three groups according to the time since symptom onset and FLAIR singal intensity of infarct lesions : symptom onset within 4.5 h; symptom onset within 4.5–6 h and FLAIR images negative for changes indicative of stroke; and symptom onset within 4.5–6 h and FLAIR images positive. Outcome of thrombolysis was evaluated for each group by recanalization rate and National Institutes of Health Stroke Scale(NIHSS) and modified Rankin Scale(m RS) scores. The hemorrhage transformation(HT) rate at7 days after thrombolysis was also compared among theree groups.Results: Mismatch between positive DWI and negative FLAIR images identi?edpatients within 3 h or 4.5 h of symptom onset with sensitivity, specificity, positive predictive value and negative predictive value of 67% and 40.9%, 77.9% and 76.9%,52.8% and 75%, and 87% and 43.5%, respectively. Recanalization rate, NHISS score and m RS score were all higher in both the 0–4.5 h and 4.5–6 h FLAIR-negative groups than that in the 4.5–6 h FLAIR-positive group(p < 0.05).The hemorrhage transformation rate at 7days after thrombolysis were 28.8%,33.3% and 53.3%,respectively.Conclusions:Patients within 4.5-6h of symptom onset with an acute ischaemic lesion detected with DWI but not with FLAIR imaging are likely to be within a time window for which thrombolysis is safe and effective.DWI-FLAIR mismatch is an objective imaging marker to identify patients with unkonwn time of symptom onset who might benefit from reperfusion therapy.PartⅡ The effect of susceptibility-weighted imaging in the guidance of outcomes of antiplatelet therapy for haemorrhage patients after thrombolysisPurpose:This study aimed to evaluated the effect of susceptibility-weighted imaging(SWI) for antiplatelet therapy on post-thrombolysis haemorrhage.Material and Methods: A total of 146 patients without symptomatic intracranial haemorrhage on computed tomography(CT) after thrombolysis were included in this study. All patients were divided into two groups:group A(n=72) received antiplatelets therapy 24 h after thrombolysis, independent of SWI-detected microbleeds(MB) or HT; group B(n=74) received antiplatelets therapy for patients without SWI-visualised haemorrhage.NIHSS score at baseline and 6h,24 h,7,14 days afher thromolysis between two groups were compared.The data of patients with SWI--detected hemorrhage after antiplatelets therapy was also analysis.The m RS score at 90 daysafter thrombolysis were calculated.Results:Haemorrhage was detected by SWI in 50 patients at 24 h after thrombolysis,22 in group A and 28 in group B. The differences in mean NIHSS score in group A were-1.6 between baseline and 6 h,-1.7 between baseline and 24 h,-3.6between baseline and 7 days and-5.9 between baseline and 14 days. The difference in mean NIHSS score in group B between baseline and 6, 24 h, 7, 14 days was-2.6,-3.3,-5.4,-8.7, respectively.The difference in reduction of mean NIHSS score between two groups from baseline was 1.0 at 6 h, 1.6 at 24 h, 1.8 at 7 days and 2.8 at14 days(p < 0.01). NIHSS scores at 7, 14 days and m RS scale at 90 days in haemorrhage patients in group B were significantly lower than that in group A,whereas the hospital stay was shorter and the rate of favourable outcome at 90 days was higher in group B than A(p < 0.05).Conclusions:Comparing with other sequences,SWI is more sensitive in detecting hameorrhage,especially in MB.SWI was an effective approach for the guidance of antiplatelet therapy on post-thrombolysis hameorrhage.