Herijgers P, Laycock S K, Ni Y, Marchal G, Bogaert J, Bosmans H, Petré C, Flameng W
Center for Experimental Surgery and Anaesthesiology, K.U. Leuven, Belgium.
Int J Card Imaging. 1997 Dec;13(6):499-507. doi: 10.1023/a:1005715426172.
Accurate localization and sizing of a myocardial infarction are necessary for clinical decision making and even more in research. Gd-Mesoporphyrin enhanced magnetic resonance imaging (MRI) was recently shown to specifically delineate necrosis in liver tumors, renal and muscle necrosis and myocardial infarction in rats. In this study, we investigated this technique's potential to accurately delineate myocardial infarction in a larger animal species, the dog.
Myocardial infarction was induced in 8 dogs by ligation of the left anterior descending coronary artery, 4 of which were reperfused after 3 hr Gd-Mesoporphyrin (0.05 mmol/kg) was injected intravenously 210 min after the onset of ischemia (n = 6) or after 24 hr in 2 dogs with non-reperfused infarctions. MRI was performed 10 hr after administration of Gd-Mesoporphyrin. In vivo MRI consisted of EKG-triggered, respiratory gated T1-weighted spin echo and segmented turboFLASH long and short axis measurements. Post-mortem, a spin echo short axis measurement was repeated. Infarct size was determined planimetrically by TTC staining of left ventricular slices.
In all instances, there was a very close qualitative agreement between the MRI and TTC defined myocardial infarction. Quantitatively, the linear regression from post-mortem MRI to TTC determined infarct size yielded a result very close to the line of identity (regression coefficient: 0.980 +/- 0.026, p < 0.000001, adjusted R2 = 0.964).
We conclude that Gd-Mesoporphyrin enhanced MRI is a promising tool for the accurate delineation of myocardial infarction.
准确确定心肌梗死的位置和大小对于临床决策至关重要，在研究中更是如此。钆-中卟啉增强磁共振成像（MRI）最近被证明可特异性描绘肝肿瘤、肾和肌肉坏死以及大鼠心肌梗死中的坏死区域。在本研究中，我们调查了该技术在更大的动物物种——狗身上准确描绘心肌梗死的潜力。
通过结扎左前降支冠状动脉在8只狗中诱导心肌梗死，其中4只在缺血开始210分钟后静脉注射钆-中卟啉（0.05 mmol/kg）3小时后再灌注（n = 6），另外2只未再灌注梗死的狗在24小时后注射。在注射钆-中卟啉10小时后进行MRI检查。体内MRI包括心电图触发、呼吸门控的T1加权自旋回波以及分段涡轮FLASH长轴和短轴测量。死后，重复进行自旋回波短轴测量。通过对左心室切片进行TTC染色，用面积测量法确定梗死面积。
在所有情况下，MRI和TTC定义的心肌梗死之间在定性上非常吻合。定量分析方面，死后MRI与TTC确定的梗死面积的线性回归结果非常接近恒等线（回归系数：0.980±0.026，p < 0.000001，调整后的R2 = 0.964）。
我们得出结论，钆-中卟啉增强MRI是准确描绘心肌梗死的一种有前景的工具。
