猪心梗模型MRI心肌首过灌注实验研究

目的 探讨缺血心肌灌注以及局部心肌的存活情况. 方法 制备成功的10只猪心梗模型分别于术前及术后24 h、72 h及1周行MRI心肌首过灌注检查,MRI检查完后处死实验猪,行TTC染色及病理检查.结果 符合实验研究10只猪术前MRI心肌首过期灌注未见灌注减低或缺损,术后8只见心肌灌注缺损和减低,灌注缺损区其灌注曲线未见明显的灌注峰,在正常心肌灌注峰值时间为低灌注表现,后期曲线呈逐渐上升表现;灌注缺损周围心肌其灌注曲线峰值信号强度低于正常侧壁和下壁心肌(P<0.05);灌注曲线峰值时间较正常侧壁和下壁心肌延迟(P<0.05).灌注缺损区TTC染色及病理均可见心肌坏死,灌注减低区见间质局灶水肿、心肌纤维水肿变性. 结论 MRI心肌首过灌注成像结合灌注曲线分析可以评价心肌活性和缺血情况.

Experimental Study of First-Pass Myocardial Perfusion MRI on Pig Myocardial Infarction Model

Objective To explore the ischemic myocardial perfusion and viability.Methods Ten successful pigs with myocardial infarction model underwent MRI first-pass myocardial perfusion examinations preoperatively and 24 hours,72 hours and one week postoperation.After MRI examinations,the experimental pigs were executed and the samples underwent TTC staining and pathological examination.Results The preoperative myocardial perfusion in the all of the 10 pigs was nomal,but there were myocardial perfusion decrease and defects in 8 experimental pigs after operation,the perfusion curves in the area with perfusion defects had no obvious peak,but there was gradual increase in the end of the performance.The perfusion peak of the area with perfusion decrease was lower than that of normal inferior and lateral myocardial wall(P＜0.05) and the peak perfusion time was delayed compared with that of normal inferior and lateral myocardial wall (P＜0.05).There was myocardial necrosis in the perfusion defects areas that was certified by TTC staining and pathological examination.The intersititial edema and myocardial degeneration could be seen in the perfusion reduced areas.Conclusion MRI fist-pass myocardial perfusion imaging combined with perfusion curve analysis can evaluate the perfusion changes of the regional myocardial microcirculation.