摘要
目的:探讨磁共振(MR)灌注成像对皮质类固醇所致股骨头缺血性坏死早期诊断的意义。方法:40只健康成年新西兰大白兔,随机分为4组,分别以大剂量皮质类固醇冲击应用、长期应用和小剂量皮质类固醇短期应用法和生理盐水对照,在给药前及给药后1、3、5、8、12、16周分别行MR常规、MR灌注成像及Gd-DTPA增强MR检查,并在扫描后分批处死动物进行病理检查。结果:大剂量皮质类固醇冲击应用和长期应用组动物均有80%发生股骨头缺血性坏死,小剂量皮质类固醇短期应用组动物未发生股骨头缺血性坏死。MR常规检查5周时敏感性为40%,8周后为100%。MR增强检查3周时敏感性50%,5周时敏感性70%,8周后为100%。MR灌注成像在应用皮质类固醇后1周即发现血流灌注异常;在3周后改变更加明显,表现为最大信号强度下降减小,峰值时间延迟。其敏感性自1周起均为100%。结论:MR灌注成像是早期诊断股骨头血流灌注异常及坏死最敏感的方法,可在超早期对股骨头缺血坏死作出预测及诊断并可反映病理过程;MR增强扫描早期诊断股骨头缺血坏死的敏感性高于MR常规扫描。三者结合可更好地反映病理学改变及病程。
Objective：To evaluate MRI feature and the value of perfusion imaging （PI） in early diagnosis of avascular necrosis of the femoral head （ANFH）.Methods：All 40 adult rabbits were randomly divided into 4 groups,group A received ultra dose corticosteroids,group B received overdose eortieosteroids in a long term, group C received small dose eortieosteroids in a short period,group D received saline as control.MRI, PI and Gd-enhaneed MR changes and pathogenic histology were observed before and 1st week,3rd week,Sth week, 8th week, 12th week and 16th week after the administration of eortieosteroids and compared with the control group.Results：Eighty percent animals in group A and B were induced ANFH.The sensitivity of MR is 40% at the 5th week,all necrosis lesions were detected at the 8th week.The sensitivity of Gd-enhanced MR is 50% at the 3rd week,70% at the 5th week.All necrosis lesions were detected at the 8th week.Initial mieroeireulatory injury of femoral head was detected at the first week by PI and more significant at the 3rd week as less marked transient decrease or no transient decrease and prolonged time to peak.Conclusion：PI Is the most sensitive method in diagnosing ANFH at initial microeirculatory injury and early necrosis stage.Gd- enhanced MR is more sensitive than MR in diagnose ANFH at early stage.The combination of MR,Gdenhanced MR and PI may reflect the pathological progression better.
出处
《中日友好医院学报》
2007年第1期28-31,36,F0003,共6页
Journal of China-Japan Friendship Hospital
关键词
皮质类周醇
缺血性坏死
股骨头
磁共振成像
灌注
eorticosteroid
avaseular necrosis
femoral head
magnetic resonance imaging
perfusion
