Contrast-enhanced multidetector computed tomography viability imaging after myocardial infarction - Characterization of myocyte death, microvascular obstruction, and chronic scar
Contrast-enhanced multidetector computed tomography viability imaging after myocardial infarction - Characterization of myocyte death, microvascular obstruction, and chronic scar
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DOI：
10.1161/circulationaha.105.521450
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发表时间：
2006-01-24
期刊：
影响因子：
37.8
通讯作者：
Lima, JAC
中科院分区：
文献类型：
--
作者：
Lardo, AC;Cordeiro, MAS;Lima, JAC
背景--区分功能障碍但存活的心肌与不存活的心肌组织的能力对心肌梗死后的预后有重要意义。本研究的目的是验证对比增强多层螺旋CT(MDCT)定量评价闭塞/再灌注性心肌梗死后心肌坏死、微血管阻塞和慢性瘢痕的准确性。方法和结果：10只狗和7只猪球囊结扎左冠状动脉前降支(LAD)，然后再通。结扎前、再通后90min(犬)或8周(猪)行增强扫描(Visipaque，150mL，325 mg/mL)，多层螺旋CT(0.5 mm×32层)。分析MDCT图像以确定梗塞的大小/范围和微血管阻塞，并与死后心肌染色(三苯基四氮唑氯化铵)和微球血流测量进行比较。急慢性脑梗塞多层螺旋CT表现为高强化，而微血管梗阻区则表现为低强化。MDCT心肌梗死体积与氯化三苯基四氮唑染色(急性心肌梗死21.1+/-7.2%对20.4+/-7.4%，平均相差0.7%；慢性心肌梗死4.15+/-1.93%对4.92+/-2.06%，平均相差-0.76%)能准确反映所有动物的形态和跨壁损伤范围。梗死区强化峰值出现在注射造影剂后5min左右。在急性研究中，MDCT也能准确识别微血管阻塞的起源区域，并与微球血流测量的血流减少区域相关联。结论-增强后的MDCT可以准确地确定和量化急性和治愈心肌梗死的空间范围。这一特征与现有的高分辨率多层螺旋CT冠状动脉成像相结合，可能对心血管疾病的综合评估具有重要意义。
Background - The ability to distinguish dysfunctional but viable myocardium from nonviable tissue has important prognostic implications after myocardial infarction. The purpose of this study was to validate the accuracy of contrast-enhanced multidetector computed tomography (MDCT) for quantifying myocardial necrosis, microvascular obstruction, and chronic scar after occlusion/reperfusion myocardial infarction.Methods and Results - Ten dogs and 7 pigs underwent balloon occlusion of the left anterior descending coronary artery (LAD) followed by reperfusion. Contrast-enhanced (Visipaque, 150 mL, 325 mg/mL) MDCT (0.5 mm x 32 slice) was performed before occlusion and 90 minutes (canine) or 8 weeks (porcine) after reperfusion. MDCT images were analyzed to define infarct size/extent and microvascular obstruction and compared with postmortem myocardial staining (triphenyltetrazolium chloride) and microsphere blood flow measurements. Acute and chronic infarcts by MDCT were characterized by hyperenhancement, whereas regions of microvascular obstruction were characterized by hypoenhancement. MDCT infarct volume compared well with triphenyltetrazolium chloride staining (acute infarcts 21.1 +/- 7.2% versus 20.4 +/- 7.4%, mean difference 0.7%; chronic infarcts 4.15 +/- 1.93% versus 4.92 +/- 2.06%, mean difference -0.76%) and accurately reflected morphology and the transmural extent of injury in all animals. Peak hyperenhancement of infarcted regions occurred approximate to 5 minutes after contrast injection. MDCT-derived regions of microvascular obstruction were also identified accurately in acute studies and correlated with reduced flow regions as measured by microsphere blood flow.Conclusions - The spatial extent of acute and healed myocardial infarction can be determined and quantified accurately with contrast-enhanced MDCT. This feature, combined with existing high-resolution MDCT coronary angiography, may have important implications for the comprehensive assessment of cardiovascular disease.