Collateral circulation formation determines the characteristic profiles of contrast-enhanced MRI in the infarcted myocardium of pigs
Collateral circulation formation determines the characteristic profiles of contrast-enhanced MRI in the infarcted myocardium of pigs
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侧枝循环的形成决定了猪梗死心肌的增强 MRI 特征
DOI：
10.1038/aps.2014.158
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发表时间：
2015-04-01
影响因子：
8.2
通讯作者：
Tian，Gang-hong
中科院分区：
文献类型：
--
作者：
Wang，Jian;Xiang，Bo;Tian，Gang-hong
目的：探讨猪心肌梗死（MI）侧支循环与MR增强信号变化的关系。分别于冠状动脉闭塞后2 h、7 d和4周行首过灌注（FPP）MRI（检测心肌灌注异常）和延迟增强（DE）MRI（判断心肌梗死）。使用非放射性红色微球评价心肌血流量（MBF）。组织学检查进行了表征infarct.Results：急性MI后2小时进行的特点是低增强FPP-DE-MRI，与小，几乎不变的FPP-signal intensity（SI）和DE-SI由于可以忽略不计的MBF。7 d后检测到的亚急性MI显示小但显著增加的FPP-SI，并且在DE-MRI中表现为缓慢的超增强，与正常心肌相比，DE-SI显著升高; MBF接近正常值的一半。4周后检测到的慢性MI显示FPP-SI与正常心肌相当，DE-MRI快速增强，DE-SI更高; MBF接近正常值。在MI的3个阶段，MBF与FPP-SI（r=+ 0.94，P< 0.01）和DE-SI峰值（r=+ 0.92，P< 0.01）相关。在亚急性和慢性periods.Conclusion：渐进性侧支恢复决定了猪急性，亚急性和慢性心肌梗死的对比增强MRI的特征性配置文件，在梗死内和梗死周围区观察到重塑血管。FPP和DE-MRI信号分布不仅取决于组织活力的丧失和扩大的间质空间，而且还取决于侧支循环的建立。
Aim:To investigate the relationship between the collateral circulation and contrast-enhanced MR signal change for myocardial infarction (MI) in pigs.Methods:Pigs underwent permanent ligation of two diagonal branches of the left anterior descending artery. First-pass perfusion (FPP) MRI (for detecting myocardial perfusion abnormalities) and delayed enhancement (DE) MRI (for estimating myocardial infarction) using Gd-DTPA were performed at 2 h, 7 d and 4 weeks after the coronary occlusion. Myocardial blood flow (MBF) was evaluated using nonradioactive red-colored microspheres. Histological examination was performed to characterize the infarcts.Results:Acute MI performed at 2 h afterwards was characterized by hypoenhancement in both FPP-and DE-MRI, with small and almost unchanged FPP-signal intensity (SI) and DE-SI due to negligible MBF. Subacute MI detected 7 d afterwards showed small but significantly increaseing FPP-SI, and was visible as a sluggish hyperenhancement in DE-MRI with considerably higher DE-SI compared to the normal myocardium; the MBF approached the half-normal value. Chronic MI detected at 4 weeks afterwards showed increasing FPP-SI comparable to the normal myocardium, and a rapid hyperenhancement in DE-MRI with even higher DE-SI; the MBF was close to the normal value. The MBF was correlated with FPP-SI (r=+ 0.94, P< 0.01) and with the peak DE-SI (r=+ 0.92, P< 0.01) at the three MI stages. Remodeled vessels were observed at intra-infarction and peri-infarction zones during the subacute and chronic periods.Conclusion:Progressive collateral recovery determines the characteristic profiles of contrast-enhanced MRI in acute, subacute and chronic myocardial infarction in pigs. The FPP-and DE-MRI signal profiles not only depend on the loss of tissue viability and enlarged interstitial space, but also on establishing a collateral circulation.