白细胞靶向超声造影显像无创评价犬心肌缺血再灌注损伤

目的 用白细胞靶向超声造影剂无创评价犬心肌缺血再灌注（ischemia-reperfusion，I-R）损伤的范围及严重程度。方法 将自制“表活显”（self-made surfactant fluorocarbon-filled microbubbles，SFCMB）与磷脂酰丝氨酸（phosphatidylserine，PS）结合，制备成白细胞靶向超声造影剂（SFCMB-PS），在实时心脏超声造影（myocardial contrast echocardiography，MCE）条件下，用SFCMB-PS对9只犬心肌I-R模型进行延迟心肌显像。实验结束后，在心肌I-R损伤处取组织块立即进行髓过氧化物酶（myeloperoxidase，MPO）活性测定。结果 延迟心肌显像可见缺血心肌部位有明显充盈缺损，而再灌注后心肌的造影剂回声明显增强。定量分析结果表明I-R损伤心肌部位声像图的灰阶强度与MPO活性有明显的相关关系（r=0．776，P〈0．05）。结论 用白细胞靶向超声造影剂评价心肌I-R损伤有明显的临床价值。

Noninvasive Imaging of Myocardial Ischemia-reperfusion Injury Using Leukocyte-targeted Contrast Echocardiography

Objective To assess the region and severity of myocardium ischemia-reperfusion(I-R)injury via noninvasive ultrasound imaging using leukocyte-targeted contrast echocardiography.Methods We incorporated the phosphatidylserine(PS)into the shell of the self-made,surfactant fluorocarbon-filled microbubbles(SFCMB)for leukocyte-targeted ultrasound contrast agent(SFCMB-PS).Nine open-chest canine myocardial ischemia-reperfusion models were established.Delayed myocardial imaging was applied by real-time myocardium contrast echocardiography(MCE)using SFCMB-PS.After experiment the myocardial tissues were cut in the region of I-R to determine tissue myeloperoxidase(MPO) activity.Results Delayed MCE imaging indicated that the clear filling defect was shown in the ischemic myocardium and the acoustic density after reperfusion was significantly increased.Quantitive analytical results demonstrated that it had an obvious correlation(r=0.776,P<0.05 )between the gray scale in the myocardial I-R region and MPO activity.Conclusions It has great clinical value for evaluating the myocardial I-R injury using leukocyte-targeted ultrasound contrast agent.