磁共振诊断早期脑缺血的新技术进展--弥散加权成像及灌注加权成像(综述)

磁共振弥散加权成像（ＤＷＩ）和血液灌注成像（ＰＷＩ）是诊断早期脑缺血的新技术；表现弥散系数、脑血流、脑血容量及平均时间是预测缺血灶结果的参数，本文综述了ＤＷＩ及ＰＷＩ的基本原理、测定技术及它们在诊断早期脑缺血方面的应用，分析了ＤＷＩ及ＰＷＩ在诊断早期脑缺血方面的相互关系，认为ＤＷＩ及ＰＷＩ能对早期脑缺血出诊确诊断信息，可反映缺血灶血流动力学的改变。

Recent advances in diagnosis of cerebral ischemia with diffusion-weighted MRI and perfusion-weighted MRI

Diffusion-weighted MRI (DW-MRI) and perfusion- weighted MRI (PW-MRI) are new techniques powerful for the assessment of acute cerebral ischemia. ADC values, cerebral blood volume(CBV), cerebral blood flow(CBF) and mean transition time(MTT) are parameters potential for predicting clinical outcome in acute ischemic patients. The basic principles , dectecting techniques and the application of DWI and PWI in early cerebral ischemia were reviewed, the correlation of perfusion-and diffusion-weighted MRI in diagnosing early cerebral ischemia were discussed. A definite diagnosis of acute cerebral ischemia would be given on both DWI and PWI, PWI would provide assessment of hemodynamics.