Abstract：Objective: To investigate the imaging evolution of the ischemic stroke in SWI, and evaluate the role of SWI in assessment of reperfusion after ischemic stroke. Methods: Fifty-four patients(30 males, 24 females, age 20~83 years, average 67 years) with cerebral infarction were performed with conventional MRI and SWI. Nine cases of hyperacute infarction(<6 hours), 18 cases of acute infarction(7~24 hours), 18 cases of subacute infarction(1.5~7days), 3 cases of stable stage(8~14days), and 6 cases of chronic infarction(>15days) were recruited in this study. Twenty-one cases with large area of infarction were followed up by SWI in this study. The presence of hemorrhage within the infarction, the extent of hemorrhage and microvascular changes around the ischemic area were observed in the follow-up images. The correlation between the extent of hemorrhage in the infarction region, the number of surrounding microvessels and the NIHSS changes were analyzed. Results: ①Hemorrhage was revealed by SWI in 16 out of 21 massive cerebral infarctions. There was a significant positive correlation between the severe hemorrhage and the NIHSS scores(rs=0.765, P=0.001). ②Among the 21 cases of large area of infarctions, increased microvessels were observed in 10 patients(47.6%). There was no significant correlation between the microvessels and the NIHSS scores changes(rs=0.408, P=0.066). Conclusion: SWI is sensitive in detecting the microbleeds in the infarction, which can be used to predict the evolution of reperfusion injury after ischemic stroke. The microvascular changes reflected on SWI can be used to assess the reperfusion status after stroke, which is helpful in guiding the clinical treatment.
2010, Vol. 21 
