García-Dorado D, Oliveras J, Gili J, Sanz E, Pérez-Villa F, Barrabés J, Carreras M J, Solares J, Soler-Soler J
Servicio de Cardiología, Hospital General Universitari Vall d'Hebron, Barcelona, Spain.
Cardiovasc Res. 1993 Aug;27(8):1462-9. doi: 10.1093/cvr/27.8.1462.
The aim was to analyse the relationship between magnetic resonance (MR) imaging parameters and myocardial water content early after coronary occlusion with or without reperfusion.
21 pigs were used. After 78 min of coronary occlusion (n = 7) or 48 min of coronary occlusion and 30 min of reperfusion (n = 14) the heart was excised. In seven animals in the reperfusion protocol the area at risk was perfused for 5 min with an anoxic buffer, starting 5 min after coronary occlusion. Serial T2 weighted and density weighted images of the heart were obtained from apex to base, by using a 1.5 tesla magnetic resonance imager. Water content was measured in samples from control and at-risk myocardium and relaxation parameters were measured in corresponding areas of the magnetic resonance images.
Water content was 399(SEM 2) ml x 100 g-1 dry tissue in control myocardium, 427(8) in ischaemic myocardium, and 511(8) in reperfused myocardium (p < 0.001). Reperfused myocardium that had received intracoronary infusion contained less water than myocardium that did not: 498(9) v 534(4) ml x 100 g-1 (p = 0.003). T2 relaxation time and T2 weighted signal intensity in the different sampling sites of magnetic resonance images correlated well with water content in the corresponding myocardial samples (r = 0.76 and r = 0.83) and with the relative volume of extracellular space, as calculated by quantitative histology (r = 0.58 and r = 0.59, p < 0.001). The increase in T2 weighted signal intensity in the area at risk with respect to control myocardium allowed differentiation between ischaemic and reperfused myocardium [9(8)% v 63(3)% respectively]. The area at risk measured by MR imaging correlated very well with that determined at pathology by the fluorescein method (r = 0.92).
Magnetic resonance imaging allows evaluation of myocardial oedema associated with acute coronary occlusion and reperfusion, and analysis of its spatial distribution. Changes in myocardial water content occurring early during acute myocardial infarction allow quantification of the area at risk and detection of reperfusion by magnetic resonance imaging.
分析冠状动脉闭塞后无论有无再灌注情况下早期磁共振（MR）成像参数与心肌含水量之间的关系。
使用21头猪。在冠状动脉闭塞78分钟（n = 7）或冠状动脉闭塞48分钟及再灌注30分钟（n = 14）后切除心脏。在再灌注方案中的7只动物中，从冠状动脉闭塞后5分钟开始，用缺氧缓冲液对危险区域灌注5分钟。使用1.5特斯拉磁共振成像仪从心尖到心底获取心脏的系列T2加权和密度加权图像。在对照和危险心肌的样本中测量含水量，并在磁共振图像的相应区域测量弛豫参数。
对照心肌的含水量为399（标准误2）ml×100 g⁻¹干组织，缺血心肌为427（8），再灌注心肌为511（8）（p < 0.001）。接受冠状动脉内灌注的再灌注心肌比未接受灌注的心肌含水量少：498（9）对534（4）ml×100 g⁻¹（p = 0.003）。磁共振图像不同采样部位的T2弛豫时间和T2加权信号强度与相应心肌样本中的含水量（r = 0.76和r = 0.83）以及通过定量组织学计算的细胞外间隙相对体积（r = 0.58和r = 0.59，p < 0.001）密切相关。与对照心肌相比，危险区域T2加权信号强度的增加使得能够区分缺血心肌和再灌注心肌[分别为9（8）%对63（3）%]。通过MR成像测量的危险区域与通过荧光素法在病理上确定的区域相关性非常好（r = 0.92）。
磁共振成像能够评估与急性冠状动脉闭塞和再灌注相关的心肌水肿，并分析其空间分布。急性心肌梗死早期发生的心肌含水量变化使得能够通过磁共振成像对危险区域进行定量并检测再灌注情况。
