Influence of severity of myocardial injury on distribution of macromolecules: Extravascular versus intravascular gadolinium-based magnetic resonance contrast agents
Influence of severity of myocardial injury on distribution of macromolecules: Extravascular versus intravascular gadolinium-based magnetic resonance contrast agents
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DOI：
10.1016/s0735-1097(97)00245-3
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发表时间：
1997-10-01
影响因子：
24
通讯作者：
Higgins, CB
中科院分区：
文献类型：
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作者：
Schwitter, J;Saeed, M;Higgins, CB
目标.本研究旨在1）比较血管外（573 Da）和血管内（92 kDa）磁共振造影剂在再灌注梗死心肌中的分布，以及2）研究损伤严重程度对这些分布模式的影响。低分子量和高分子量造影剂的心肌分布取决于血管通透性、心肌内的扩散/对流转运和细胞内室的可及性（细胞完整性）。为了改变心肌损伤的严重程度，72只大鼠进行20，30，45或75分钟（n = 18，分别）的冠状动脉闭塞。再流2 h后，动物接受0.05 mmol/kg二亚乙基三胺五乙酸钆-二甲酰胺（Gd-DTPA-BMA）（n = 24）、（Gd DTPA）（30）-白蛋白（n = 24）或生理盐水（对照组，n = 24）。注射后3分钟，切除心脏并进行成像（自旋回波成像参数：重复时间300 ms，回波时间8 ms，2-特斯拉系统），随后进行氯化三苯基四氮唑染色用于梗死检测和大小测定。组织形态计量学和MR梗死面积（表示为切片表面的百分比）相关性良好：Gd-DTPA BMA的r = 0.96;（Gd-DTPA）（30）-白蛋白的r = 0.95。在Gd-DTPA-CMA增强图像上，再灌注心肌梗死呈均匀强化。梗死/正常心肌的信号强度比随着缺血持续时间的增加而增加（总体p < 0.0001，方差分析[ANOVA]），表明缺血后心肌中Gd-DTPA-BMA的分布体积增加。在（Gd-DTPA）（30）-白蛋白增强图像上，再灌注梗死由明亮的边界区和增强较弱的中央核心组成。核心的范围随着缺血持续时间的增加而增加（总体p值< 0.0001，ANOVA）。在再灌注2小时，MR造影剂在缺血后心肌中的分布1）对血管外和血管内药物具有特异性，2）受缺血持续时间的调节。(C)1997年，美国心脏病学会。
Objectives. This study sought to 1) compare the distribution of extravascular (573 Da) and intravascular (92 kDa) magnetic resonance (MR) contrast agents in reperfused infarcted myocardium, and 2) investigate the effect of injury severity on these distribution patterns.Background. Myocardial distribution of low and high molecular lar weight contrast agents depends on vascular permeability, diffusive/convective transport within the interstitium and accessibility of the intracellular compartment (cellular integrity).Methods. To vary the severity of myocardial injury, 72 rats were subjected to 20, 30, 45 or 75 min (n = 18, respectively) of coronary artery occlusion. After 2 h of reflow, the animals received either 0.05 mmol/kg of gadolinium diethylenetriaminepentaacetic acid-bismethylamide (Gd-DTPA-BMA) (n = 24), (Gd DTPA)(30)- albumin (n = 24) or saline (control group, n = 24). Three minutes after injection, the hearts were excised and imaged (spin-echo imaging parameters: repetition time 300 ms, echo time 8 ms, 2-tesla system), followed by triphenyltetrazolium chloride staining for infarct detection and sizing.Results. Histomorphometric and MR infarct size (expressed as percent of slice surface) correlated well: r = 0.96 for Gd-DTPA BMA; r = 0.95 for (Gd-DTPA)(30)-albumin. On Gd-DTPA BMA-enhanced images, reperfused myocardial infarctions were homo geneously enhanced. The ratio of signal intensity of infarcted/normal myocardium increased with increasing duration of ischemia (overall p < 0.0001, analysis of variance [ANOVA]), indicating an increase in the distribution volume of Gd-DTPA-BMA in postischemic myocardium. On (Gd-DTPA)(30)-albumin-enhanced images, reperfused infarctions consisted of a bright border zone and a less enhanced central core. The extent of the core increased with increasing duration of ischemia (overall p value < 0.0001, ANOVA).Conclusions. At 2 h of reperfusion, the distribution of MR contrast agents in postischemic myocardium is 1) specific for extravascular and intravascular agents, and 2) modulated by the duration of ischemia. (C) 1997 by the American College of Cardiology.