犬心肌梗塞的MRI与病理对照研究

Comparative Study of MRI and Pathologic Findings in Canine Myocardial Infarction

目的：研究心肌梗塞演变过程中不同时期的ＭＲＩ影像特征及其病理基础。探讨ＭＲＩ在心肌梗塞方面的应用价值。材料与方法：２５只杂种犬结扎冠状动脉左前降支后，于心肌梗塞演变过程的不同时期行ＭＲＩ平扫、电影（Ｃｉｎｅ）磁共振成像和ＧｄＤＴＰＡ增强扫描。取心脏标本进行病理检查。结果：ＭＲＩ平扫不能区别梗塞心肌和非梗塞心肌。ＣｉｎｅＭＲＩ能真实反映梗塞心肌的部位、厚度及运动功能状态。心肌梗塞演变的不同时期，由于其病理基础不同，产生不同的ＧｄＤＴＰＡ增强表现。结论：ＣｉｎｅＭＲＩ及ＧｄＤＴＰＡ增强ＭＲＩ是敏感而又可靠地能显示各期心肌梗塞。

Objective: To study the MRI features and its pathologic basis in different stage of canine myocardial infarction. To evaluate the application of MRI in myocardial infarction. Materials and Methods: After the left anterior descending branch of the coronary artery being ligated, the experimental dogs underwent precontrast MRI, GdDTPA enhanced MRI and Cine MRI at different progressing stage of myocardial infarction. Histopathologic examination of myocardial specimen was made. Results: Infarcted area could not be differentiated from noninfarcted area on plain MR images. Cine MRI well demonstrated the site and size of infarction, the thickness of the infarcted myocardial wall and the dynamic status of the heart. GdDTPA enhanced MRI findings varied from stage to stage due to different pathologic changes. Conclusion: Cine MRI and GdDTPA are very sensitive and specific in demonstrating myocardial infarction of different progressing stage.