The Susceptibility Weighted Imaging And Clinical Analysis Of Hemorrhagic Transformation After Cerebral Infarction

Objective:To check the more exact incidence of Hemorrhagic transformation aftercerebral infraction by susceptibility weighted imaging（SWI）and explore the bleedingtime、pathogenesis、predilection site、prognosis and risk factors of it.Materials and Methods:Extraction96cases of cerebral infarction were enrolled hospital and had SWI、CT、traditional MRI examination successively within1week、2weeks、3weeks afterthe outbreak of the disease. Then we analysed imaging, collected the clinical data andobserved the changes of patients’ condition. The risk factors of HT was firstlyanalysed by using univariate analysis, the variables screened statistically significantwhich were then analysed by logistical regression. Meanwhile．The ratio of thehemorrhage area（the most massive hemorrhage area/the biggest infarction area）andNIHSS score changes in value before and after hemorrhage （the score afterhemorrhage minus the score before hemorrhage） were done by the correlationanalysis.Results:The total incidence rate of HT is35.4％，which was observed in34patients bySWI examination (100％), in26patients by CT and in19patients by traditionalMRI， SWI could showed larger and clearer focus of hemorrhage than CT andtraditional MRI. HT, which could happened earliest in the first day after the outbreakof the disease, was found16cases within the first week(47.1%),12cases within thesecond week(35.3%) and6cases within the third week(17.6%). There were14HTcases of the parenchymal hematoma (41％),20HT cases of the hemorrhagicinfarction (59％) in34patients. SWI showed that HT was located within the infarctor edge and typically occured in the cerebral cortex infarction (65%), the lesionmorphology of which presented with irregular patchy, spot-like and low signal slugwith local fusion shadow and high density film at the edge of edema. The univariateanalysis demonstrated there were significant differences in age（≥66岁）, high blood sugar, high blood pressure, large cerebral infarction, atrial fibrillation between HTgroup and NHT group（P<0.05）, while no statistically differences could been found insmoking, alcohol consumption, high cholesterol, atherosclerotic plaque and history ofcranial vascular disease between2groups（P>0.05）. The logistic regression analysisshowed that HT was significantly independently associated respectively with largecerebral infarction（OR=6.913，P=0.035<0.05）,atrial fibrillation（OR=5.881，P=0.047<0.05）and age（≥66岁）（OR=3.275，P=0.043<0.05）. A linear positivecorrelation was found between the ratio of the hemorrhage area and NIHSS scorechanges in value before and after hemorrhage(r=0.828、P<0.01), which implied thatthe NIHSS score difference was greater with the increase of the ratio of thehemorrhage area.Conclusion:1、SWI could sensitively detected hemorrhage and was with obvious advantagescompared with CT and traditional MRI, which was considered as the preferredscreening method for HT.2、HT，the incidence rate of which in this group was35.4％，mostly occurred inthe fist week （47.1%) while it took35.3%in the second week and17.6%in the thirdweek. Ｍostly occurred in the cerebral cortex．The parenchymal hematoma（ＰＨ）was mainly seen within1week, possibly due to embolus transitional and vascularrecanalization.The hemorrhagic infarction(ＨＩ) was mainly seen after1week, thepathogenesis of which was related with the establish of collateral circulation.3、Along with the increase of the ratio of the hemorrhage area, clinical symptomsappeared aggravating and the difference of NIHSS scores got bigger with poorprognosis.4、Large area infarction,atrial fibrillation and age（≥66岁） were independentrisk factors of HT and the imaging examination should been reviewed within1week,especially SWI.5、The predictors of HT were drawn less at present. The pathogenesis andlong-term prognosis of HT should be further discussed to find more and more reliablerisk factors.