Stanford Stroke Center, Ste 205, 780 Welch Road, Palo Alto 94304, California, USA.
Rev Neurol (Paris). 2011 Dec;167(12):873-80. doi: 10.1016/j.neurol.2011.10.002. Epub 2011 Nov 23.
The extent of the penumbra and the core of an acute ischemic stroke influence, at the given time, the impact of the recanalization of the occluded vessel on the outcome. Research studies have demonstrated that quantitative MR diffusion imaging and, to a lesser extent, CT perfusion (CTP) could provide an acceptable estimation of the size of the core, while perfusion imaging thresholds could outline critically hypoperfused regions. Several software programs now automatically process reliable quantitative diffusion-weighted imaging (DWI) and perfusion maps in real time, making them available for clinical routine. Studies investigating whether acute MRI profile could select patient for acute recanalization after the 4.5h time window approved for rtPA administration are ongoing. Transient ischemic attack (TIA) is a major risk factor for stroke but its clinical diagnosis is difficult. MRI can confirm the ischemic nature of transient neurological symptoms among 50% of the patients and the presence of an acute diffusion lesion is an independent risk factor for acute stroke. Multimodal imaging of ischemic stroke and TIA provides a tissue-based characterization of the ischemic lesion that is dramatically influencing the diagnosis and the management of the patients.
急性缺血性卒中的半影区和核心区在特定时间内影响闭塞血管再通对结局的影响。研究表明，定量磁共振弥散成像（DWI），在一定程度上，CT 灌注（CTP）可以对核心区的大小提供可接受的估计，而灌注成像阈值可以描绘出严重低灌注区域。现在，有几个软件程序可以实时自动处理可靠的定量弥散加权成像（DWI）和灌注图，使其可用于临床常规。目前正在进行研究，以探讨急性 MRI 特征是否可以选择在 rtPA 给药的 4.5 小时时间窗后进行急性再通的患者。短暂性脑缺血发作（TIA）是中风的主要危险因素，但临床诊断较为困难。MRI 可以在 50%的患者中证实短暂性神经症状的缺血性质，而急性弥散性病变是急性中风的独立危险因素。缺血性卒中和 TIA 的多模态成像提供了对缺血性病变的基于组织的特征描述，这极大地影响了患者的诊断和管理。
