NEW MRI TECHNIQUES PRIOR TO T-PA THERAPY AFTER STROKE

急性脑卒中的治疗尚无有效的治疗方法 直到1995年，组织纤溶酶原激活物（tPA）被证明可以改善 神经和功能结果的中风患者， 三个小时的症状发作目前，许多患者不符合tPA的条件 治疗，因为目前的评估超过3小时后，中风发作。 尝试将治疗窗口扩大到6小时，使用计算机 断层扫描（CT）选择患者已经成功。初步数据 这表明，新的磁共振成像（MRI）技术很可能是 比CT更有效地识别可能对 tPA治疗。研究人员建议将强大的新MRI技术应用于 研究特定的MRI特征是否能预测良好的临床反应 在中风后3至6小时之间给予静脉内tPA治疗 发病他们假设那些可能从治疗中获益的患者亚组 血栓溶解疗法可以基于血流和血栓形成的组合来确定。 参数和早期缺血性脑损伤程度的评估- 与CT不同，新的MRI技术对这些变量非常敏感。在 这项多中心、开放标签、试点临床试验，80名患者将接受 MRI扫描，包括弥散加权成像、灌注加权成像和 磁共振血管造影，在接受tPA治疗前即刻3 - 6 在中风发作后的几小时内。两次随访MRI扫描将评估早期 再灌注发生并建立最终的梗塞体积。临床 对治疗的反应将由改善的量 基线NIH卒中量表（NIHSS）评分与30天评分之间的差异， 达到"有利的临床反应"的比率（8分改善或 基线至30天之间NIHSS评分完全恢复）至tPA 疗法将使用Barthel指数和 改良兰金量表。这项研究将提供重要的数据需要规划一个 随机、安慰剂对照临床试验，旨在确定 具有特定MRI特征的卒中患者受益于tPA治疗 在中风发作后3 - 6小时之间施用。

Effective therapy was not available for treatment of acute stroke until 1995 when tissue plasminogen activator (tPA) was shown to improve neurologic and functional outcome in stroke patients who were treated within three hours of symptom onset. Currently, many patients do not qualify for tPA therapy because the present for evaluation beyond 3 hours after stroke onset. Attempts to expand the treatment window to 6 hours, using computerized tomography (CT) to select patients have been successful. Preliminary data suggest that new magnetic resonance imaging (MRI) techniques are likely to be more effective than CT for identifying patients who may respond favorably to tPA therapy. Investigators propose to apply robust new MRI techniques to investigate whether specific MRI profiles predict a favorable clinical response to intravenous tPA therapy administered between 3 and 6 hours after stroke onset. They hypothesize that patient subgroups who are likely to benefit from thrombolytic therapy can be identified based on a combination of blood flow parameters and an assessment of the degree of early ischemic brain injury - variables for which new MRI techniques, unlike CT, are extremely sensitive. In this multicenter, open-label, pilot clinical trial, 80 patients will receive an MRI scan with diffusion-weighted imaging, perfusion-weighted imaging and magnetic resonance angiography, immediately prior to receiving tPA therapy 3-6 hours after stroke onset. Two follow-up MRI scans will assess whether early reperfusion occurs and establish the final infarct volume. The clinical response to therapy will be determined both by the amount of improvement between the baseline NIH Stroke Scale (NIHSS) score and the 30-day score and the rate of achieving a "favorable clinical response" ((8 point improvement or complete recovery in the NIHSS score between baseline and 30 days) to tPA therapy. Three-month outcomes will be assessed with the Barthel Index and the Modified Rankin Scale. This study will provide important data needed to plan a randomized, placebo-controlled, clinical trial designed to determine whether stroke patients with specific MRI characteristics benefit from tPA therapy administered between 3-6 hours after stroke onset.