Discrimination of myocardial acute and chronic (scar) infarctions on delayed contrast enhanced magnetic resonance imaging with intravascular magnetic resonance contrast media
Discrimination of myocardial acute and chronic (scar) infarctions on delayed contrast enhanced magnetic resonance imaging with intravascular magnetic resonance contrast media
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DOI：
10.1016/j.jacc.2006.03.071
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发表时间：
2006-11-21
影响因子：
24
通讯作者：
Higgins, Charles B.
中科院分区：
文献类型：
--
作者：
Saeed, Maythern;Weber, Oliver;Higgins, Charles B.
目的探讨血管内Gd-络合物在区分急性和慢性心肌梗死(MI)中的作用。背景：标准细胞外Gd-络合物延迟增强磁共振成像的一个潜在局限性是不能区分急性和慢性MI。在血管内和细胞外注射Gd-螯合物前后分别进行反转恢复梯度回波(IR-GRE)、T-1增强自旋回波(TSE)和T-2-TSE成像。死后用三苯基四氮唑氯化铵(TTC)描绘脑梗塞。用Masson‘s三色染色和生物素标记的单叶巴氏杆菌Isolectin B4染色来表征瘢痕心肌。结果血管内药物对急性心肌梗死3天有不同程度的强化(SI比5.8+/-1.3)，8周无明显强化(1.6+/-0.4，p<；0.01)。该细胞外药物对急性(SI比7.7+/-1.4)和慢性(7.5+/-0.9)脑梗塞均有不同程度的强化作用。血管内(16.0+/-1.3%)和细胞外(17.1+/-1.7%)药物治疗后，急性心肌梗死的强化范围无差异，8周时细胞外强化和TTC强化范围较小(分别为13.2+/-1.4%和12.0+/-1.5%)。马森三色染色显示密集的疤痕组织，标志着梗塞完全愈合。血管染色显示瘢痕组织中微血管较少，呈杂乱排列。结论血管内和细胞外Gd络合物结合可在延迟成像上区分急性和慢性脑梗塞。这种双对比剂法可以用来确定梗塞的年龄和范围。
OBJECTIVES The purpose of this study was to examine the potential of intravascular gadolinium (Gd)-chelates in discriminating acute from chronic myocardial infarctions (MIs).BACKGROUND A potential limitation of delayed contrast enhanced magnetic resonance imaging with standard extracellular Gd-chelates is its inability to distinguish acute from chronic MIs.METHODS Eight pigs with MIs were studied at 3 days and 8 weeks. Inversion recovery gradient echo (IR-GRE), T-1-turbo spin echo (TSE), and T-2-TSE images were acquired before and after administration of intravascular and extracellular Gd-chelates. Triphenyltetrazolium chloride (TTC) was used to delineate infarctions at postmortem. Masson's trichrome and Biotinylated Bandeiria simplicifolia Isolectin B4 stains were used to characterize scarred myocardium. Analysis of variance was used to compare signal intensity (SI) ratios and determine differences in infarct extent.RESULTS The intravascular agent produced diffierential enhancement of acute infarctions at 3 days (SI ratio 5.8 +/- 1.3) but not at 8 weeks (1.6 +/- 0.4, p < 0.01). The extracellular agent provided diffierential enhancement of both acute (SI ratio 7.7 +/- 1.4) and chronic (7.5 +/- 0.9) infarctions. The extents of enhanced regions in acute infarctions were not different after intravascular (16.0 +/- 1.3%) or extracellular (17.1 +/- 1.7%) agents; at 8 weeks the extent of extracellular enhanced and TTC regions were smaller (13.2 +/- 1.4% and 12.0 +/- 1.5%, respectively). Masson's trichrome stain demonstrated dense scar tissue, signaling the complete healing of infarction. The vascular stain showed that scar tissue contained fewer microvessels oriented in a haphazard array.dCONCLUSIONS The combination of intravascular and extracellular Gd-chelates discriminates acute from chronic infarctions on delayed images. This double contrast agent approach can be used to determine the age and extent of infarctions.